Transcriptome analysis of genes involved in defense against alkaline stress in roots of wild jujube (Ziziphus acidojujuba)

PubMed Central

Tian, Shan; Wang, Bei; Zhao, Xusheng

2017-01-01

Wild jujube (Ziziphus acidojujuba Mill.) is highly tolerant to alkaline, saline and drought stress; however, no studies have performed transcriptome profiling to study the response of wild jujube to these and other abiotic stresses. In this study, we examined the tolerance of wild jujube to NaHCO3-NaOH solution and analyzed gene expression profiles in response to alkaline stress. Physiological experiments revealed that H2O2 content in leaves increased significantly and root activity decreased quickly during alkaline of pH 9.5 treatment. For transcriptome analysis, wild jujube plants grown hydroponically were treated with NaHCO3-NaOH solution for 0, 1, and 12 h and six transcriptomes from roots were built. In total, 32,758 genes were generated, and 3,604 differentially expressed genes (DEGs) were identified. After 1 h, 853 genes showed significantly different expression between control and treated plants; after 12 h, expression of 2,856 genes was significantly different. The expression pattern of nine genes was validated by quantitative real-time PCR. After gene annotation and gene ontology enrichment analysis, the genes encoding transcriptional factors, serine/threonine-protein kinases, heat shock proteins, cysteine-like kinases, calmodulin-like proteins, and reactive oxygen species (ROS) scavengers were found to be closely involved in alkaline stress response. These results will provide useful insights for elucidating the mechanisms underlying alkaline tolerance in wild jujube. PMID:28976994

Comparative analysis of transcriptome in two wheat genotypes with contrasting levels of drought tolerance

USDA-ARS?s Scientific Manuscript database

Drought tolerance is a complex trait that is governed by multiple genes. To identify the potential candidate genes, comparative analysis of drought stress-responsive transcriptome between drought-tolerant (Triticum aestivum Cv. C306) and drought-sensitive (Triticum aestivum Cv. WL711) genotypes was ...

Genome-wide transcriptomic analysis of BR-deficient Micro-Tom reveals correlations between drought stress tolerance and brassinosteroid signaling in tomato.

PubMed

Lee, Jinsu; Shim, Donghwan; Moon, Suyun; Kim, Hyemin; Bae, Wonsil; Kim, Kyunghwan; Kim, Yang-Hoon; Rhee, Sung-Keun; Hong, Chang Pyo; Hong, Suk-Young; Lee, Ye-Jin; Sung, Jwakyung; Ryu, Hojin

2018-06-01

Brassinosteroids (BRs) are plant steroid hormones that play crucial roles in a range of growth and developmental processes. Although BR signal transduction and biosynthetic pathways have been well characterized in model plants, their biological roles in an important crop, tomato (Solanum lycopersicum), remain unknown. Here, cultivated tomato (WT) and a BR synthesis mutant, Micro-Tom (MT), were compared using physiological and transcriptomic approaches. The cultivated tomato showed higher tolerance to drought and osmotic stresses than the MT tomato. However, BR-defective phenotypes of MT, including plant growth and stomatal closure defects, were completely recovered by application of exogenous BR or complementation with a SlDWARF gene. Using genome-wide transcriptome analysis, 619 significantly differentially expressed genes (DEGs) were identified between WT and MT plants. Several DEGs were linked to known signaling networks, including those related to biotic/abiotic stress responses, lignification, cell wall development, and hormone responses. Consistent with the higher susceptibility of MT to drought stress, several gene sets involved in responses to drought and osmotic stress were differentially regulated between the WT and MT tomato plants. Our data suggest that BR signaling pathways are involved in mediating the response to abiotic stress via fine-tuning of abiotic stress-related gene networks in tomato plants. Copyright © 2018. Published by Elsevier Masson SAS.

Transcriptome Analysis of the Role of GlnD/GlnBK in Nitrogen Stress Adaptation by Sinorhizobium meliloti Rm1021

PubMed Central

Yurgel, Svetlana N.; Rice, Jennifer; Kahn, Michael L.

2013-01-01

Transcriptional changes in the nitrogen stress response (NSR) of wild type S. meliloti Rm1021, and isogenic strains missing both PII proteins, GlnB and GlnK, or carrying a ΔglnD-sm2 mutation were analyzed using whole-genome microarrays. This approach allowed us to identify a number of new genes involved in the NSR and showed that the response of these bacteria to nitrogen stress overlaps with other stress responses, including induction of the fixK2 transcriptional activator and genes that are part of the phosphate stress response. Our data also show that GlnD and GlnBK proteins may regulate many genes that are not part of the NSR. Analysis of transcriptome profiles of the Rm1021 ΔglnD-sm2 strain allowed us to identify several genes that appear to be regulated by GlnD without the participation of the PII proteins. PMID:23516427

Analysis of differential gene expression in response to handling and confinement stress in rainbow trout using whole transcriptome RNA-seq

USDA-ARS?s Scientific Manuscript database

Fish under intensive rearing conditions experience various stress conditions, which have negative impacts on survival, growth and fillet quality. Understanding the molecular mechanisms underlying stress responses will facilitate improvement of animal welfare and production efficiency. Our objective ...

Transcriptome-Wide Identification of Reference Genes for Expression Analysis of Soybean Responses to Drought Stress along the Day.

PubMed

Marcolino-Gomes, Juliana; Rodrigues, Fabiana Aparecida; Fuganti-Pagliarini, Renata; Nakayama, Thiago Jonas; Ribeiro Reis, Rafaela; Bouças Farias, Jose Renato; Harmon, Frank G; Correa Molinari, Hugo Bruno; Correa Molinari, Mayla Daiane; Nepomuceno, Alexandre

2015-01-01

The soybean transcriptome displays strong variation along the day in optimal growth conditions and also in response to adverse circumstances, like drought stress. However, no study conducted to date has presented suitable reference genes, with stable expression along the day, for relative gene expression quantification in combined studies on drought stress and diurnal oscillations. Recently, water deficit responses have been associated with circadian clock oscillations at the transcription level, revealing the existence of hitherto unknown processes and increasing the demand for studies on plant responses to drought stress and its oscillation during the day. We performed data mining from a transcriptome-wide background using microarrays and RNA-seq databases to select an unpublished set of candidate reference genes, specifically chosen for the normalization of gene expression in studies on soybean under both drought stress and diurnal oscillations. Experimental validation and stability analysis in soybean plants submitted to drought stress and sampled during a 24 h timecourse showed that four of these newer reference genes (FYVE, NUDIX, Golgin-84 and CYST) indeed exhibited greater expression stability than the conventionally used housekeeping genes (ELF1-β and β-actin) under these conditions. We also demonstrated the effect of using reference candidate genes with different stability values to normalize the relative expression data from a drought-inducible soybean gene (DREB5) evaluated in different periods of the day.

Expression of OsMYB55 in maize activates stress-responsive genes and enhances heat and drought tolerance.

PubMed

Casaretto, José A; El-Kereamy, Ashraf; Zeng, Bin; Stiegelmeyer, Suzy M; Chen, Xi; Bi, Yong-Mei; Rothstein, Steven J

2016-04-29

Plant response mechanisms to heat and drought stresses have been considered in strategies for generating stress tolerant genotypes, but with limited success. Here, we analyzed the transcriptome and improved tolerance to heat stress and drought of maize plants over-expressing the OsMYB55 gene. Over-expression of OsMYB55 in maize decreased the negative effects of high temperature and drought resulting in improved plant growth and performance under these conditions. This was evidenced by the higher plant biomass and reduced leaf damage exhibited by the transgenic lines compared to wild type when plants were subjected to individual or combined stresses and during or after recovery from stress. A global transcriptomic analysis using RNA sequencing revealed that several genes induced by heat stress in wild type plants are constitutively up-regulated in OsMYB55 transgenic maize. In addition, a significant number of genes up-regulated in OsMYB55 transgenic maize under control or heat treatments have been associated with responses to abiotic stresses including high temperature, dehydration and oxidative stress. The latter is a common and major consequence of imposed heat and drought conditions, suggesting that this altered gene expression may be associated with the improved stress tolerance in these transgenic lines. Functional annotation and enrichment analysis of the transcriptome also pinpoint the relevance of specific biological processes for stress responses. Our results show that expression of OsMYB55 can improve tolerance to heat stress and drought in maize plants. Enhanced expression of stress-associated genes may be involved in OsMYB55-mediated stress tolerance. Possible implications for the improved tolerance to heat stress and drought of OsMYB55 transgenic maize are discussed.

Systems Biology Analysis of Zymomonas mobilis ZM4 Ethanol Stress Responses

PubMed Central

Yang, Shihui; Pan, Chongle; Tschaplinski, Timothy J.; Hurst, Gregory B.; Engle, Nancy L.; Zhou, Wen; Dam, PhuongAn; Xu, Ying; Rodriguez, Miguel; Dice, Lezlee; Johnson, Courtney M.; Davison, Brian H.; Brown, Steven D.

2013-01-01

Background Zymomonas mobilis ZM4 is a capable ethanologenic bacterium with high ethanol productivity and ethanol tolerance. Previous studies indicated that several stress-related proteins and changes in the ZM4 membrane lipid composition may contribute to ethanol tolerance. However, the molecular mechanisms of its ethanol stress response have not been elucidated fully. Methodology/Principal Findings In this study, ethanol stress responses were investigated using systems biology approaches. Medium supplementation with an initial 47 g/L (6% v/v) ethanol reduced Z. mobilis ZM4 glucose consumption, growth rate and ethanol productivity compared to that of untreated controls. A proteomic analysis of early exponential growth identified about one thousand proteins, or approximately 55% of the predicted ZM4 proteome. Proteins related to metabolism and stress response such as chaperones and key regulators were more abundant in the early ethanol stress condition. Transcriptomic studies indicated that the response of ZM4 to ethanol is dynamic, complex and involves many genes from all the different functional categories. Most down-regulated genes were related to translation and ribosome biogenesis, while the ethanol-upregulated genes were mostly related to cellular processes and metabolism. Transcriptomic data were used to update Z. mobilis ZM4 operon models. Furthermore, correlations among the transcriptomic, proteomic and metabolic data were examined. Among significantly expressed genes or proteins, we observe higher correlation coefficients when fold-change values are higher. Conclusions Our study has provided insights into the responses of Z. mobilis to ethanol stress through an integrated “omics” approach for the first time. This systems biology study elucidated key Z. mobilis ZM4 metabolites, genes and proteins that form the foundation of its distinctive physiology and its multifaceted response to ethanol stress. PMID:23874800

Gene expression analysis of rocket salad under pre-harvest and postharvest stresses: A transcriptomic resource for Diplotaxis tenuifolia

PubMed Central

Cavaiuolo, Marina; Cocetta, Giacomo; Spadafora, Natasha Damiana; Müller, Carsten T.; Rogers, Hilary J.

2017-01-01

Diplotaxis tenuifolia L. is of important economic value in the fresh-cut industry for its nutraceutical and sensorial properties. However, information on the molecular mechanisms conferring tolerance of harvested leaves to pre- and postharvest stresses during processing and shelf-life have never been investigated. Here, we provide the first transcriptomic resource of rocket by de novo RNA sequencing assembly, functional annotation and stress-induced expression analysis of 33874 transcripts. Transcriptomic changes in leaves subjected to commercially-relevant pre-harvest (salinity, heat and nitrogen starvation) and postharvest stresses (cold, dehydration, dark, wounding) known to affect quality and shelf-life were analysed 24h after stress treatment, a timing relevant to subsequent processing of salad leaves. Transcription factors and genes involved in plant growth regulator signaling, autophagy, senescence and glucosinolate metabolism were the most affected by the stresses. Hundreds of genes with unknown function but uniquely expressed under stress were identified, providing candidates to investigate stress responses in rocket. Dehydration and wounding had the greatest effect on the transcriptome and different stresses elicited changes in the expression of genes related to overlapping groups of hormones. These data will allow development of approaches targeted at improving stress tolerance, quality and shelf-life of rocket with direct applications in the fresh-cut industries. PMID:28558066

Gene expression analysis of rocket salad under pre-harvest and postharvest stresses: A transcriptomic resource for Diplotaxis tenuifolia.

PubMed

Cavaiuolo, Marina; Cocetta, Giacomo; Spadafora, Natasha Damiana; Müller, Carsten T; Rogers, Hilary J; Ferrante, Antonio

2017-01-01

Diplotaxis tenuifolia L. is of important economic value in the fresh-cut industry for its nutraceutical and sensorial properties. However, information on the molecular mechanisms conferring tolerance of harvested leaves to pre- and postharvest stresses during processing and shelf-life have never been investigated. Here, we provide the first transcriptomic resource of rocket by de novo RNA sequencing assembly, functional annotation and stress-induced expression analysis of 33874 transcripts. Transcriptomic changes in leaves subjected to commercially-relevant pre-harvest (salinity, heat and nitrogen starvation) and postharvest stresses (cold, dehydration, dark, wounding) known to affect quality and shelf-life were analysed 24h after stress treatment, a timing relevant to subsequent processing of salad leaves. Transcription factors and genes involved in plant growth regulator signaling, autophagy, senescence and glucosinolate metabolism were the most affected by the stresses. Hundreds of genes with unknown function but uniquely expressed under stress were identified, providing candidates to investigate stress responses in rocket. Dehydration and wounding had the greatest effect on the transcriptome and different stresses elicited changes in the expression of genes related to overlapping groups of hormones. These data will allow development of approaches targeted at improving stress tolerance, quality and shelf-life of rocket with direct applications in the fresh-cut industries.

Transcriptome responses of an ungrafted Phytophthora root rot tolerant avocado (Persea americana) rootstock to flooding and Phytophthora cinnamomi.

PubMed

Reeksting, B J; Olivier, N A; van den Berg, N

2016-09-22

Avocado (Persea americana Mill.) is a commercially important fruit crop worldwide. A major limitation to production is the oomycete Phytophthora cinnamomi, which causes root rot leading to branch-dieback and tree death. The decline of orchards infected with P. cinnamomi occurs much faster when exposed to flooding, even if flooding is only transient. Flooding is a multifactorial stress compromised of several individual stresses, making breeding and selection for tolerant varieties challenging. With more plantations occurring in marginal areas, with imperfect irrigation and drainage, understanding the response of avocado to these stresses will be important for the industry. Maintenance of energy production was found to be central in the response to flooding, as seen by up-regulation of transcripts related to glycolysis and induction of transcripts related to ethanolic fermentation. Energy-intensive processes were generally down-regulated, as evidenced by repression of transcripts related to processes such as secondary cell-wall biosynthesis as well as defence-related transcripts. Aquaporins were found to be down-regulated in avocado roots exposed to flooding, indicating reduced water-uptake under these conditions. The transcriptomic response of avocado to flooding and P. cinnamomi was investigated utilizing microarray analysis. Differences in the transcriptome caused by the presence of the pathogen were minor compared to transcriptomic perturbations caused by flooding. The transcriptomic response of avocado to flooding reveals a response to flooding that is conserved in several species. This data could provide key information that could be used to improve selection of stress tolerant rootstocks in the avocado industry.

Global analysis of gene expression in maize leaves treated with low temperature. II. Combined effect of severe cold (8 °C) and circadian rhythm.

PubMed

Jończyk, M; Sobkowiak, A; Trzcinska-Danielewicz, J; Skoneczny, M; Solecka, D; Fronk, J; Sowiński, P

2017-10-01

In maize seedlings, severe cold results in dysregulation of circadian pattern of gene expression causing profound modulation of transcription of genes related to photosynthesis and other key biological processes. Plants live highly cyclic life and their response to environmental stresses must allow for underlying biological rhythms. To study the interplay of a stress and a rhythmic cue we investigated transcriptomic response of maize seedlings to low temperature in the context of diurnal gene expression. Severe cold stress had pronounced effect on the circadian rhythm of a substantial proportion of genes. Their response was strikingly dual, comprising either flattening (partial or complete) of the diel amplitude or delay of expression maximum/minimum by several hours. Genes encoding central oscillator components behaved in the same dual manner, unlike their Arabidopsis counterparts reported earlier to cease cycling altogether upon cold treatment. Also numerous genes lacking circadian rhythm responded to the cold by undergoing up- or down-regulation. Notably, the transcriptome changes preceded major physiological manifestations of cold stress. In silico analysis of metabolic processes likely affected by observed gene expression changes indicated major down-regulation of photosynthesis, profound and multifarious modulation of plant hormone levels, and of chromatin structure, transcription, and translation. A role of trehalose and stachyose in cold stress signaling was also suggested. Meta-analysis of published transcriptomic data allowed discrimination between general stress response of maize and that unique to severe cold. Several cis- and trans-factors likely involved in the latter were predicted, albeit none of them seemed to have a major role. These results underscore a key role of modulation of diel gene expression in maize response to severe cold and the unique character of the cold-response of the maize circadian clock.

Transcriptomic analysis of Petunia hybrida in response to salt stress using high throughput RNA sequencing.

PubMed

Villarino, Gonzalo H; Bombarely, Aureliano; Giovannoni, James J; Scanlon, Michael J; Mattson, Neil S

2014-01-01

Salinity and drought stress are the primary cause of crop losses worldwide. In sodic saline soils sodium chloride (NaCl) disrupts normal plant growth and development. The complex interactions of plant systems with abiotic stress have made RNA sequencing a more holistic and appealing approach to study transcriptome level responses in a single cell and/or tissue. In this work, we determined the Petunia transcriptome response to NaCl stress by sequencing leaf samples and assembling 196 million Illumina reads with Trinity software. Using our reference transcriptome we identified more than 7,000 genes that were differentially expressed within 24 h of acute NaCl stress. The proposed transcriptome can also be used as an excellent tool for biological and bioinformatics in the absence of an available Petunia genome and it is available at the SOL Genomics Network (SGN) http://solgenomics.net. Genes related to regulation of reactive oxygen species, transport, and signal transductions as well as novel and undescribed transcripts were among those differentially expressed in response to salt stress. The candidate genes identified in this study can be applied as markers for breeding or to genetically engineer plants to enhance salt tolerance. Gene Ontology analyses indicated that most of the NaCl damage happened at 24 h inducing genotoxicity, affecting transport and organelles due to the high concentration of Na+ ions. Finally, we report a modification to the library preparation protocol whereby cDNA samples were bar-coded with non-HPLC purified primers, without affecting the quality and quantity of the RNA-seq data. The methodological improvement presented here could substantially reduce the cost of sample preparation for future high-throughput RNA sequencing experiments.

Transcriptomic Analysis of Petunia hybrida in Response to Salt Stress Using High Throughput RNA Sequencing

PubMed Central

Villarino, Gonzalo H.; Bombarely, Aureliano; Giovannoni, James J.; Scanlon, Michael J.; Mattson, Neil S.

2014-01-01

Salinity and drought stress are the primary cause of crop losses worldwide. In sodic saline soils sodium chloride (NaCl) disrupts normal plant growth and development. The complex interactions of plant systems with abiotic stress have made RNA sequencing a more holistic and appealing approach to study transcriptome level responses in a single cell and/or tissue. In this work, we determined the Petunia transcriptome response to NaCl stress by sequencing leaf samples and assembling 196 million Illumina reads with Trinity software. Using our reference transcriptome we identified more than 7,000 genes that were differentially expressed within 24 h of acute NaCl stress. The proposed transcriptome can also be used as an excellent tool for biological and bioinformatics in the absence of an available Petunia genome and it is available at the SOL Genomics Network (SGN) http://solgenomics.net. Genes related to regulation of reactive oxygen species, transport, and signal transductions as well as novel and undescribed transcripts were among those differentially expressed in response to salt stress. The candidate genes identified in this study can be applied as markers for breeding or to genetically engineer plants to enhance salt tolerance. Gene Ontology analyses indicated that most of the NaCl damage happened at 24 h inducing genotoxicity, affecting transport and organelles due to the high concentration of Na+ ions. Finally, we report a modification to the library preparation protocol whereby cDNA samples were bar-coded with non-HPLC purified primers, without affecting the quality and quantity of the RNA-seq data. The methodological improvement presented here could substantially reduce the cost of sample preparation for future high-throughput RNA sequencing experiments. PMID:24722556

Genome-wide analysis of drought induced gene expression changes in flax (Linum usitatissimum).

PubMed

Dash, Prasanta K; Cao, Yongguo; Jailani, Abdul K; Gupta, Payal; Venglat, Prakash; Xiang, Daoquan; Rai, Rhitu; Sharma, Rinku; Thirunavukkarasu, Nepolean; Abdin, Malik Z; Yadava, Devendra K; Singh, Nagendra K; Singh, Jas; Selvaraj, Gopalan; Deyholos, Mike; Kumar, Polumetla Ananda; Datla, Raju

2014-01-01

A robust phenotypic plasticity to ward off adverse environmental conditions determines performance and productivity in crop plants. Flax (linseed), is an important cash crop produced for natural textile fiber (linen) or oilseed with many health promoting products. This crop is prone to drought stress and yield losses in many parts of the world. Despite recent advances in drought research in a number of important crops, related progress in flax is very limited. Since, response of this plant to drought stress has not been addressed at the molecular level; we conducted microarray analysis to capture transcriptome associated with induced drought in flax. This study identified 183 differentially expressed genes (DEGs) associated with diverse cellular, biophysical and metabolic programs in flax. The analysis also revealed especially the altered regulation of cellular and metabolic pathways governing photosynthesis. Additionally, comparative transcriptome analysis identified a plethora of genes that displayed differential regulation both spatially and temporally. These results revealed co-regulated expression of 26 genes in both shoot and root tissues with implications for drought stress response. Furthermore, the data also showed that more genes are upregulated in roots compared to shoots, suggesting that roots may play important and additional roles in response to drought in flax. With prolonged drought treatment, the number of DEGs increased in both tissue types. Differential expression of selected genes was confirmed by qRT-PCR, thus supporting the suggested functional association of these intrinsic genes in maintaining growth and homeostasis in response to imminent drought stress in flax. Together the present study has developed foundational and new transcriptome data sets for drought stress in flax.

Transcriptome characterization of immune suppression from battlefield-like stress

PubMed Central

Muhie, S; Hammamieh, R; Cummings, C; Yang, D; Jett, M

2013-01-01

Transcriptome alterations of leukocytes from soldiers who underwent 8 weeks of Army Ranger training (RASP, Ranger Assessment and Selection Program) were analyzed to evaluate impacts of battlefield-like stress on the immune response. About 1400 transcripts were differentially expressed between pre- and post-RASP leukocytes. Upon functional analysis, immune response was the most enriched biological process, and most of the transcripts associated with the immune response were downregulated. Microbial pattern recognition, chemotaxis, antigen presentation and T-cell activation were among the most downregulated immune processes. Transcription factors predicted to be stress-inhibited (IRF7, RELA, NFκB1, CREB1, IRF1 and HMGB) regulated genes involved in inflammation, maturation of dendritic cells and glucocorticoid receptor signaling. Many altered transcripts were predicted to be targets of stress-regulated microRNAs. Post-RASP leukocytes exposed ex vivo to Staphylococcal enterotoxin B showed a markedly impaired immune response to this superantigen compared with pre-RASP leukocytes, consistent with the suppression of the immune response revealed by transcriptome analyses. Our results suggest that suppression of antigen presentation and lymphocyte activation pathways, in the setting of normal blood cell counts, most likely contribute to the poor vaccine response, impaired wound healing and infection susceptibility associated with chronic intense stress. PMID:23096155

Transcriptome Analysis of Spartina pectinata in Response to Freezing Stress

PubMed Central

Nah, Gyoungju; Lee, Moonsub; Kim, Do-Soon; Rayburn, A. Lane; Voigt, Thomas; Lee, D. K.

2016-01-01

Prairie cordgrass (Spartina pectinata), a perennial C4 grass native to the North American prairie, has several distinctive characteristics that potentially make it a model crop for production in stressful environments. However, little is known about the transcriptome dynamics of prairie cordgrass despite its unique freezing stress tolerance. Therefore, the purpose of this work was to explore the transcriptome dynamics of prairie cordgrass in response to freezing stress at -5°C for 5 min and 30 min. We used a RNA-sequencing method to assemble the S. pectinata leaf transcriptome and performed gene-expression profiling of the transcripts under freezing treatment. Six differentially expressed gene (DEG) groups were categorized from the profiling. In addition, two major consecutive orders of gene expression were observed in response to freezing; the first being the acute up-regulation of genes involved in plasma membrane modification, calcium-mediated signaling, proteasome-related proteins, and transcription regulators (e.g., MYB and WRKY). The follow-up and second response was of genes involved in encoding the putative anti-freezing protein and the previously known DNA and cell-damage-repair proteins. Moreover, we identified the genes involved in epigenetic regulation and circadian-clock expression. Our results indicate that freezing response in S. pectinata reflects dynamic changes in rapid-time duration, as well as in metabolic, transcriptional, post-translational, and epigenetic regulation. PMID:27032112

Poplar trees reconfigure the transcriptome and metabolome in response to drought in a genotype- and time-of-day-dependent manner.

PubMed

Hamanishi, Erin T; Barchet, Genoa L H; Dauwe, Rebecca; Mansfield, Shawn D; Campbell, Malcolm M

2015-04-21

Drought has a major impact on tree growth and survival. Understanding tree responses to this stress can have important application in both conservation of forest health, and in production forestry. Trees of the genus Populus provide an excellent opportunity to explore the mechanistic underpinnings of forest tree drought responses, given the growing molecular resources that are available for this taxon. Here, foliar tissue of six water-deficit stressed P. balsamifera genotypes was analysed for variation in the metabolome in response to drought and time of day by using an untargeted metabolite profiling technique, gas chromatography/mass-spectrometry (GC/MS). Significant variation in the metabolome was observed in response the imposition of water-deficit stress. Notably, organic acid intermediates such as succinic and malic acid had lower concentrations in leaves exposed to drought, whereas galactinol and raffinose were found in increased concentrations. A number of metabolites with significant difference in accumulation under water-deficit conditions exhibited intraspecific variation in metabolite accumulation. Large magnitude fold-change accumulation was observed in three of the six genotypes. In order to understand the interaction between the transcriptome and metabolome, an integrated analysis of the drought-responsive transcriptome and the metabolome was performed. One P. balsamifera genotype, AP-1006, demonstrated a lack of congruence between the magnitude of the drought transcriptome response and the magnitude of the metabolome response. More specifically, metabolite profiles in AP-1006 demonstrated the smallest changes in response to water-deficit conditions. Pathway analysis of the transcriptome and metabolome revealed specific genotypic responses with respect to primary sugar accumulation, citric acid metabolism, and raffinose family oligosaccharide biosynthesis. The intraspecific variation in the molecular strategies that underpin the responses to drought among genotypes may have an important role in the maintenance of forest health and productivity.

Transcriptomic and Proteomic Analysis of Oenococcus oeni Adaptation to Wine Stress Conditions

PubMed Central

Margalef-Català, Mar; Araque, Isabel; Bordons, Albert; Reguant, Cristina; Bautista-Gallego, Joaquín

2016-01-01

Oenococcus oeni, the main lactic acid bacteria responsible for malolactic fermentation in wine, has to adapt to stressful conditions, such as low pH and high ethanol content. In this study, the changes in the transcriptome and the proteome of O. oeni PSU-1 during the adaptation period before MLF start have been studied. DNA microarrays were used for the transcriptomic analysis and two complementary proteomic techniques, 2-D DIGE and iTRAQ labeling were used to analyze the proteomic response. One of the most influenced functions in PSU-1 due to inoculation into wine-like medium (WLM) was translation, showing the over-expression of certain ribosomal genes and the corresponding proteins. Amino acid metabolism and transport was also altered and several peptidases were up regulated both at gene and protein level. Certain proteins involved in glutamine and glutamate metabolism showed an increased abundance revealing the key role of nitrogen uptake under stressful conditions. A strong transcriptional inhibition of carbohydrate metabolism related genes was observed. On the other hand, the transcriptional up-regulation of malate transport and citrate consumption was indicative of the use of L-malate and citrate associated to stress response and as an alternative energy source to sugar metabolism. Regarding the stress mechanisms, our results support the relevance of the thioredoxin and glutathione systems in the adaptation of O. oeni to wine related stress. Genes and proteins related to cell wall showed also significant changes indicating the relevance of the cell envelop as protective barrier to environmental stress. The differences found between transcriptomic and proteomic data suggested the relevance of post-transcriptional mechanisms and the complexity of the stress response in O. oeni adaptation. Further research should deepen into the metabolisms mostly altered due to wine conditions to elucidate the role of each mechanism in the O. oeni ability to develop MLF. PMID:27746771

Comprehensive analysis of transcriptome response to salinity stress in the halophytic turf grass Sporobolus virginicus

PubMed Central

Yamamoto, Naoki; Takano, Tomoyuki; Tanaka, Keisuke; Ishige, Taichiro; Terashima, Shin; Endo, Chisato; Kurusu, Takamitsu; Yajima, Shunsuke; Yano, Kentaro; Tada, Yuichi

2015-01-01

The turf grass Sporobolus virginicus is halophyte and has high salinity tolerance. To investigate the molecular basis of its remarkable tolerance, we performed Illumina high-throughput RNA sequencing on roots and shoots of a S. virginicus genotype under normal and saline conditions. The 130 million short reads were assembled into 444,242 unigenes. A comparative analysis of the transcriptome with rice and Arabidopsis transcriptome revealed six turf grass-specific unigenes encoding transcription factors. Interestingly, all of them showed root specific expression and five of them encode bZIP type transcription factors. Another remarkable transcriptional feature of S. virginicus was activation of specific pathways under salinity stress. Pathway enrichment analysis suggested transcriptional activation of amino acid, pyruvate, and phospholipid metabolism. Up-regulation of several unigenes, previously shown to respond to salt stress in other halophytes was also observed. Gene Ontology enrichment analysis revealed that unigenes assigned as proteins in response to water stress, such as dehydrin and aquaporin, and transporters such as cation, amino acid, and citrate transporters, and H+-ATPase, were up-regulated in both shoots and roots under salinity. A correspondence analysis of the enriched pathways in turf grass cells, but not in rice cells, revealed two groups of unigenes similarly up-regulated in the turf grass in response to salt stress; one of the groups, showing excessive up-regulation under salinity, included unigenes homologos to salinity responsive genes in other halophytes. Thus, the present study identified candidate genes involved in salt tolerance of S. virginicus. This genetic resource should be valuable for understanding the mechanisms underlying high salt tolerance in S. virginicus. This information can also provide insight into salt tolerance in other halophytes. PMID:25954282

De novo assembly and characterization of Muscovy duck liver transcriptome and analysis of differentially regulated genes in response to heat stress.

PubMed

Zeng, Tao; Zhang, Liping; Li, Jinjun; Wang, Deqian; Tian, Yong; Lu, Lizhi

2015-05-01

High temperature is a major abiotic stress limiting animal growth and productivity worldwide. The Muscovy duck (Cairina moschata), sometimes called the Barbary drake, is a type of duck with a fairly unusual domestication history. In Southeast Asia, duck meat is one of the top meats consumed, and as such, the production of the meat is an important topic of research. The transcriptomic and genomic data presently available are insufficient to understanding the molecular mechanism underlying the heat tolerance of Muscovy ducks. Thus, transcriptome and expression profiling data for this species are required as important resource for identifying genes and developing molecular marker. In this study, de novo transcriptome assembly and gene expression analysis using Illumina sequencing technology were performed. More than 225 million clean reads were generated and assembled into 36,903 unique transcripts with an average length of 1,135 bp. A total of 21,221 (57.50 %) unigenes were annotated. Gene Ontology (GO) analysis of the annotated unigenes revealed that the majority of sequenced genes were associated with transcription, signal transduction, and apoptosis. We also performed gene expression profiling analysis upon heat treatment in Muscovy ducks and identified 470 heat-response unique transcripts. GO term enrichment showed that protein folding and chaperone binding were significant enrichment, whereas KEGG pathway analyses showed that Ras and MAPKs were activated after heat stress in Muscovy ducks. Our research enriched sequences information of Muscovy duck, provided novel insights into responses to heat stress in these ducks, and serve as candidate genes or markers that can be used to guide future efforts to breed heat-tolerant duck strains.

The response of Isidorella newcombi to copper exposure: Using an integrated biological framework to interpret transcriptomic responses from RNA-seq analysis.

PubMed

Ubrihien, Rodney P; Ezaz, Tariq; Taylor, Anne M; Stevens, Mark M; Krikowa, Frank; Foster, Simon; Maher, William A

2017-04-01

This study describes the transcriptomic response of the Australian endemic freshwater gastropod Isidorella newcombi exposed to 80±1μg/L of copper for 3days. Analysis of copper tissue concentration, lysosomal membrane destabilisation and RNA-seq were conducted. Copper tissue concentrations confirmed that copper was bioaccumulated by the snails. Increased lysosomal membrane destabilisation in the copper-exposed snails indicated that the snails were stressed as a result of the exposure. Both copper tissue concentrations and lysosomal destabilisation were significantly greater in snails exposed to copper. In order to interpret the RNA-seq data from an ecotoxicological perspective an integrated biological response model was developed that grouped transcriptomic responses into those associated with copper transport and storage, survival mechanisms and cell death. A conceptual model of expected transcriptomic changes resulting from the copper exposure was developed as a basis to assess transcriptomic responses. Transcriptomic changes were evident at all the three levels of the integrated biological response model. Despite lacking statistical significance, increased expression of the gene encoding copper transporting ATPase provided an indication of increased internal transport of copper. Increased expression of genes associated with endocytosis are associated with increased transport of copper to the lysosome for storage in a detoxified form. Survival mechanisms included metabolic depression and processes associated with cellular repair and recycling. There was transcriptomic evidence of increased cell death by apoptosis in the copper-exposed organisms. Increased apoptosis is supported by the increase in lysosomal membrane destabilisation in the copper-exposed snails. Transcriptomic changes relating to apoptosis, phagocytosis, protein degradation and the lysosome were evident and these processes can be linked to the degradation of post-apoptotic debris. The study identified contaminant specific transcriptomic markers as well as markers of general stress. From an ecotoxicological perspective, the use of a framework to group transcriptomic responses into those associated with copper transport, survival and cell death assisted with the complex process of interpretation of RNA-seq data. The broad adoption of such a framework in ecotoxicology studies would assist in comparison between studies and the identification of reliable transcriptomic markers of contaminant exposure and response. Copyright © 2017 Elsevier B.V. All rights reserved.

Autotoxicity mechanism of Oryza sativa: transcriptome response in rice roots exposed to ferulic acid

PubMed Central

2013-01-01

Background Autotoxicity plays an important role in regulating crop yield and quality. To help characterize the autotoxicity mechanism of rice, we performed a large-scale, transcriptomic analysis of the rice root response to ferulic acid, an autotoxin from rice straw. Results Root growth rate was decreased and reactive oxygen species, calcium content and lipoxygenase activity were increased with increasing ferulic acid concentration in roots. Transcriptome analysis revealed more transcripts responsive to short ferulic-acid exposure (1- and 3-h treatments, 1,204 genes) than long exposure (24 h, 176 genes). Induced genes were involved in cell wall formation, chemical detoxification, secondary metabolism, signal transduction, and abiotic stress response. Genes associated with signaling and biosynthesis for ethylene and jasmonic acid were upregulated with ferulic acid. Ferulic acid upregulated ATP-binding cassette and amino acid/auxin permease transporters as well as genes encoding signaling components such as leucine-rich repeat VIII and receptor-like cytoplasmic kinases VII protein kinases, APETALA2/ethylene response factor, WRKY, MYB and Zinc-finger protein expressed in inflorescence meristem transcription factors. Conclusions The results of a transcriptome analysis suggest the molecular mechanisms of plants in response to FA, including toxicity, detoxicification and signaling machinery. FA may have a significant effect on inhibiting rice root elongation through modulating ET and JA hormone homeostasis. FA-induced gene expression of AAAP transporters may contribute to detoxicification of the autotoxin. Moreover, the WRKY and Myb TFs and LRR-VIII and SD-2b kinases might regulate downstream genes under FA stress but not general allelochemical stress. This comprehensive description of gene expression information could greatly facilitate our understanding of the mechanisms of autotoxicity in plants. PMID:23705659

Genome-wide analysis on Chlamydomonas reinhardtii reveals the impact of hydrogen peroxide on protein stress responses and overlap with other stress transcriptomes

DOE PAGES

Blaby, Ian K.; Blaby-Haas, Crysten E.; Pérez-Pérez, María Esther; ...

2015-12-07

Reactive oxygen species (ROS) are produced by and have the potential to be damaging to all aerobic organisms. In photosynthetic organisms, they are an unavoidable byproduct of electron transfer in both the chloroplast and mitochondrion. Here, in this paper, we employ the reference unicellular green alga Chlamydomonas reinhardtii to identify the effect of H 2O 2 on gene expression by monitoring the changes in the transcriptome in a time-course experiment. Comparison of transcriptomes from cells sampled immediately prior to the addition of H 2O 2 and 0.5 and 1 h subsequently revealed 1278 differentially abundant transcripts. Of those transcripts thatmore » increase in abundance, many encode proteins involved in ROS detoxification, protein degradation and stress responses, whereas among those that decrease are transcripts encoding proteins involved in photosynthesis and central carbon metabolism. In addition to these transcriptomic adjustments, we observe that addition of H 2O 2 is followed by an accumulation and oxidation of the total intracellular glutathione pool, and a decrease in photosynthetic O 2 output. Additionally, we analyze our transcriptomes in the context of changes in transcript abundance in response to singlet O 2 (O 2 *), and relate our H 2O 2-induced transcripts to a diurnal transcriptome, where we demonstrate enrichments of H 2O 2-induced transcripts early in the light phase, late in the light phase and 2 h prior to light. In conclusion, on this basis several genes that are highlighted in this work may be involved in previously undiscovered stress remediation pathways or acclimation responses.« less

Changes in the transcriptomic profiles of maize roots in response to iron-deficiency stress.

PubMed

Li, Yan; Wang, Nian; Zhao, Fengtao; Song, Xuejiao; Yin, Zhaohua; Huang, Rong; Zhang, Chunqing

2014-07-01

Plants are often subjected to iron (Fe)-deficiency stress because of its low solubility. Plants have evolved two distinct strategies to solubilize and transport Fe to acclimate to this abiotic stress condition. Transcriptomic profiling analysis was performed using Illumina digital gene expression to understand the mechanism underlying resistance responses of roots to Fe starvation in maize, an important Strategy II plant. A total of 3,427, 4,069, 4,881, and 2,610 genes had significantly changed expression levels after Fe-deficiency treatments of 1, 2, 4 or 7 days, respectively. Genes involved in 2'-deoxymugineic acid (DMA) synthesis, secretion, and Fe(III)-DMA uptake were significantly induced. Many genes related to plant hormones, protein kinases, and protein phosphatases responded to Fe-deficiency stress, suggesting their regulatory roles in response to the Fe-deficiency stress. Functional annotation clustering analysis, using the Database for Annotation, Visualization and Integrated Discovery, revealed maize root responses to Fe starvation. This resulted in 38 functional annotation clusters: 25 for up-regulated genes, and 13 for down-regulated ones. These included genes encoding enzymes involved in the metabolism of carboxylic acids, isoprenoids and aromatic compounds, transporters, and stress response proteins. Our work provides integrated information for understanding maize response to Fe-deficiency stress.

Transcriptomic analysis of the hepatic response to stress in the red cusk-eel (Genypterus chilensis): Insights into lipid metabolism, oxidative stress and liver steatosis

PubMed Central

Aedo, Jorge E.; Zuloaga, Rodrigo; Maldonado, Jonathan; Bastias-Molina, Macarena; Silva, Herman; Meneses, Claudio; Gallardo-Escarate, Cristian; Molina, Alfredo

2017-01-01

Teleosts exhibit a broad divergence in their adaptive response to stress, depending on the magnitude, duration, and frequency of stressors and the species receiving the stimulus. We have previously reported that the red cusk-eel (Genypterus chilensis), an important marine farmed fish, shows a physiological response to stress that results in increased skeletal muscle atrophy mediated by over-expression of components of the ubiquitin proteasome and autophagy-lysosomal systems. To better understand the systemic effects of stress on the red cusk-eel metabolism, the present study assessed the transcriptomic hepatic response to repetitive handling-stress. Using high-throughput RNA-seq, 259 up-regulated transcripts were found, mostly associated with angiogenesis, gluconeogenesis, and triacylglyceride catabolism. Conversely, 293 transcripts were down-regulated, associated to cholesterol biosynthesis, PPARα signaling, fatty acid biosynthesis, and glycolysis. This gene signature was concordant with hepatic metabolite levels and hepatic oxidative damage. Moreover, the increased plasmatic levels of AST (aspartate aminotransferase), ALT (alanine aminotransferase) and AP (alkaline phosphatase), as well as liver histology suggest stress-induced liver steatosis. This study offers an integrative molecular and biochemical analysis of the hepatic response to handling-stress, and reveals unknown aspects of lipid metabolism in a non-model teleost. PMID:28448552

Comparative Transcriptomic Analysis of the Response of Dunaliella acidophila (Chlorophyta) to Short-Term Cadmium and Chronic Natural Metal-Rich Water Exposures.

PubMed

Puente-Sánchez, Fernando; Olsson, Sanna; Aguilera, Angeles

2016-10-01

Heavy metals are toxic compounds known to cause multiple and severe cellular damage. However, acidophilic extremophiles are able to cope with very high concentrations of heavy metals. This study investigated the stress response under natural environmental heavy metal concentrations in an acidophilic Dunaliella acidophila. We employed Illumina sequencing for a de novo transcriptome assembly and to identify changes in response to high cadmium concentrations and natural metal-rich water. The photosynthetic performance was also estimated by pulse amplitude-modulated (PAM) fluorescence. Transcriptomic analysis highlights a number of processes mainly related to a high constitutive expression of genes involved in oxidative stress and response to reactive oxygen species (ROS), even in the absence of heavy metals. Photosynthetic activity seems to be unaltered under short-term exposition to Cd and chronic exposure to natural metal-rich water, probably due to an increase in the synthesis of structural photosynthetic components preserving their functional integrity. An overrepresentation of Gene Ontology (GO) terms related to metabolic activities, transcription, and proteosomal catabolic process was observed when D. acidophila grew under chronic exposure to natural metal-rich water. GO terms involved in carbohydrate metabolic process, reticulum endoplasmic and Golgi bodies, were also specifically overrepresented in natural metal-rich water library suggesting an endoplasmic reticulum stress response.

Transcriptome analysis of Pinus halepensis under drought stress and during recovery

PubMed Central

Fox, Hagar; Doron-Faigenboim, Adi; Kelly, Gilor; Bourstein, Ronny; Attia, Ziv; Zhou, Jing; Moshe, Yosef; Moshelion, Menachem; David-Schwartz, Rakefet

2018-01-01

Abstract Forest trees use various strategies to cope with drought stress and these strategies involve complex molecular mechanisms. Pinus halepensis Miller (Aleppo pine) is found throughout the Mediterranean basin and is one of the most drought-tolerant pine species. In order to decipher the molecular mechanisms that P. halepensis uses to withstand drought, we performed large-scale physiological and transcriptome analyses. We selected a mature tree from a semi-arid area with suboptimal growth conditions for clonal propagation through cuttings. We then used a high-throughput experimental system to continuously monitor whole-plant transpiration rates, stomatal conductance and the vapor pressure deficit. The transcriptomes of plants were examined at six physiological stages: pre-stomatal response, partial stomatal closure, minimum transpiration, post-irrigation, partial recovery and full recovery. At each stage, data from plants exposed to the drought treatment were compared with data collected from well-irrigated control plants. A drought-stressed P. halepensis transcriptome was created using paired-end RNA-seq. In total, ~6000 differentially expressed, non-redundant transcripts were identified between drought-treated and control trees. Cluster analysis has revealed stress-induced down-regulation of transcripts related to photosynthesis, reactive oxygen species (ROS)-scavenging through the ascorbic acid (AsA)-glutathione cycle, fatty acid and cell wall biosynthesis, stomatal activity, and the biosynthesis of flavonoids and terpenoids. Up-regulated processes included chlorophyll degradation, ROS-scavenging through AsA-independent thiol-mediated pathways, abscisic acid response and accumulation of heat shock proteins, thaumatin and exordium. Recovery from drought induced strong transcription of retrotransposons, especially the retrovirus-related transposon Tnt1-94. The drought-related transcriptome illustrates this species’ dynamic response to drought and recovery and unravels novel mechanisms. PMID:29177514

Transcriptome analysis of Pinus halepensis under drought stress and during recovery.

PubMed

Fox, Hagar; Doron-Faigenboim, Adi; Kelly, Gilor; Bourstein, Ronny; Attia, Ziv; Zhou, Jing; Moshe, Yosef; Moshelion, Menachem; David-Schwartz, Rakefet

2018-03-01

Forest trees use various strategies to cope with drought stress and these strategies involve complex molecular mechanisms. Pinus halepensis Miller (Aleppo pine) is found throughout the Mediterranean basin and is one of the most drought-tolerant pine species. In order to decipher the molecular mechanisms that P. halepensis uses to withstand drought, we performed large-scale physiological and transcriptome analyses. We selected a mature tree from a semi-arid area with suboptimal growth conditions for clonal propagation through cuttings. We then used a high-throughput experimental system to continuously monitor whole-plant transpiration rates, stomatal conductance and the vapor pressure deficit. The transcriptomes of plants were examined at six physiological stages: pre-stomatal response, partial stomatal closure, minimum transpiration, post-irrigation, partial recovery and full recovery. At each stage, data from plants exposed to the drought treatment were compared with data collected from well-irrigated control plants. A drought-stressed P. halepensis transcriptome was created using paired-end RNA-seq. In total, ~6000 differentially expressed, non-redundant transcripts were identified between drought-treated and control trees. Cluster analysis has revealed stress-induced down-regulation of transcripts related to photosynthesis, reactive oxygen species (ROS)-scavenging through the ascorbic acid (AsA)-glutathione cycle, fatty acid and cell wall biosynthesis, stomatal activity, and the biosynthesis of flavonoids and terpenoids. Up-regulated processes included chlorophyll degradation, ROS-scavenging through AsA-independent thiol-mediated pathways, abscisic acid response and accumulation of heat shock proteins, thaumatin and exordium. Recovery from drought induced strong transcription of retrotransposons, especially the retrovirus-related transposon Tnt1-94. The drought-related transcriptome illustrates this species' dynamic response to drought and recovery and unravels novel mechanisms.

Integrated transcriptomic and proteomic analysis of the bile stress response in probiotic Lactobacillus salivarius LI01.

PubMed

Lv, Long-Xian; Yan, Ren; Shi, Hai-Yan; Shi, Ding; Fang, Dai-Qiong; Jiang, Hui-Yong; Wu, Wen-Rui; Guo, Fei-Fei; Jiang, Xia-Wei; Gu, Si-Lan; Chen, Yun-Bo; Yao, Jian; Li, Lan-Juan

2017-01-06

Lactobacillus salivarius LI01, isolated from healthy humans, has demonstrated probiotic properties in the prevention and treatment of liver failure. Tolerance to bile stress is crucial to allow lactobacilli to survive in the gastrointestinal tract and exert their benefits. In this work, we used a Digital Gene Expression transcriptomic and iTRAQ LC-MS/MS proteomic approach to examine the characteristics of LI01 in response to bile stress. Using culture medium with or without 0.15% ox bile, 591 differentially transcribed genes and 347 differentially expressed proteins were detected in LI01. Overall, we found the bile resistance of LI01 to be based on a highly remodeled cell envelope and a reinforced bile efflux system rather than on the activity of bile salt hydrolases. Additionally, some differentially expressed genes related to regulatory systems, the general stress response and central metabolism processes, also play roles in stress sensing, bile-induced damage prevention and energy efficiency. Moreover, bile salts appear to enhance proteolysis and amino acid uptake (especially aromatic amino acids) by LI01, which may support the liver protection properties of this strain. Altogether, this study establishes a model of global response mechanism to bile stress in L. salivarius LI01. L. salivarius strain LI01 exhibits not only antibacterial and antifungal properties but also exerts a good health-promoting effect in acute liver failure. As a potential probiotic strain, the bile-tolerance trait of strain LI01 is important, though this has not yet been explored. In this study, an analysis based on DGE and iTRAQ was performed to investigate the gene expression in strain LI01 under bile stress at the mRNA and protein levels, respectively. To our knowledge, this work also represents the first combined transcriptomic and proteomic analysis of the bile stress response mechanism in L. salivarius. Copyright © 2016. Published by Elsevier B.V.

Transcriptome Sequencing of Dianthus spiculifolius and Analysis of the Genes Involved in Responses to Combined Cold and Drought Stress.

PubMed

Zhou, Aimin; Ma, Hongping; Liu, Enhui; Jiang, Tongtong; Feng, Shuang; Gong, Shufang; Wang, Jingang

2017-04-17

Dianthus spiculifolius , a perennial herbaceous flower and a member of the Caryophyllaceae family, has strong resistance to cold and drought stresses. To explore the transcriptional responses of D. spiculifolius to individual and combined stresses, we performed transcriptome sequencing of seedlings under normal conditions or subjected to cold treatment (CT), simulated drought treatment (DT), or their combination (CTDT). After de novo assembly of the obtained reads, 112,015 unigenes were generated. Analysis of differentially expressed genes (DEGs) showed that 2026, 940, and 2346 genes were up-regulated and 1468, 707, and 1759 were down-regulated in CT, DT, and CTDT samples, respectively. Among all the DEGs, 182 up-regulated and 116 down-regulated genes were identified in all the treatment groups. Analysis of metabolic pathways and regulatory networks associated with the DEGs revealed overlaps and cross-talk between cold and drought stress response pathways. The expression profiles of the selected DEGs in CT, DT, and CTDT samples were characterized and confirmed by quantitative RT-PCR. These DEGs and metabolic pathways may play important roles in the response of D. spiculifolius to the combined stress. Functional characterization of these genes and pathways will provide new targets for enhancement of plant stress tolerance through genetic manipulation.

Transcriptome Sequencing of Dianthus spiculifolius and Analysis of the Genes Involved in Responses to Combined Cold and Drought Stress

PubMed Central

Zhou, Aimin; Ma, Hongping; Liu, Enhui; Jiang, Tongtong; Feng, Shuang; Gong, Shufang; Wang, Jingang

2017-01-01

Dianthus spiculifolius, a perennial herbaceous flower and a member of the Caryophyllaceae family, has strong resistance to cold and drought stresses. To explore the transcriptional responses of D. spiculifolius to individual and combined stresses, we performed transcriptome sequencing of seedlings under normal conditions or subjected to cold treatment (CT), simulated drought treatment (DT), or their combination (CTDT). After de novo assembly of the obtained reads, 112,015 unigenes were generated. Analysis of differentially expressed genes (DEGs) showed that 2026, 940, and 2346 genes were up-regulated and 1468, 707, and 1759 were down-regulated in CT, DT, and CTDT samples, respectively. Among all the DEGs, 182 up-regulated and 116 down-regulated genes were identified in all the treatment groups. Analysis of metabolic pathways and regulatory networks associated with the DEGs revealed overlaps and cross-talk between cold and drought stress response pathways. The expression profiles of the selected DEGs in CT, DT, and CTDT samples were characterized and confirmed by quantitative RT-PCR. These DEGs and metabolic pathways may play important roles in the response of D. spiculifolius to the combined stress. Functional characterization of these genes and pathways will provide new targets for enhancement of plant stress tolerance through genetic manipulation. PMID:28420173

Transcriptomic Changes Drive Physiological Responses to Progressive Drought Stress and Rehydration in Tomato

PubMed Central

Iovieno, Paolo; Punzo, Paola; Guida, Gianpiero; Mistretta, Carmela; Van Oosten, Michael J.; Nurcato, Roberta; Bostan, Hamed; Colantuono, Chiara; Costa, Antonello; Bagnaresi, Paolo; Chiusano, Maria L.; Albrizio, Rossella; Giorio, Pasquale; Batelli, Giorgia; Grillo, Stefania

2016-01-01

Tomato is a major crop in the Mediterranean basin, where the cultivation in the open field is often vulnerable to drought. In order to adapt and survive to naturally occurring cycles of drought stress and recovery, plants employ a coordinated array of physiological, biochemical, and molecular responses. Transcriptomic studies on tomato responses to drought and subsequent recovery are few in number. As the search for novel traits to improve the genetic tolerance to drought increases, a better understanding of these responses is required. To address this need we designed a study in which we induced two cycles of prolonged drought stress and a single recovery by rewatering in tomato. In order to dissect the complexity of plant responses to drought, we analyzed the physiological responses (stomatal conductance, CO2 assimilation, and chlorophyll fluorescence), abscisic acid (ABA), and proline contents. In addition to the physiological and metabolite assays, we generated transcriptomes for multiple points during the stress and recovery cycles. Cluster analysis of differentially expressed genes (DEGs) between the conditions has revealed potential novel components in stress response. The observed reduction in leaf gas exchanges and efficiency of the photosystem PSII was concomitant with a general down-regulation of genes belonging to the photosynthesis, light harvesting, and photosystem I and II category induced by drought stress. Gene ontology (GO) categories such as cell proliferation and cell cycle were also significantly enriched in the down-regulated fraction of genes upon drought stress, which may contribute to explain the observed growth reduction. Several histone variants were also repressed during drought stress, indicating that chromatin associated processes are also affected by drought. As expected, ABA accumulated after prolonged water deficit, driving the observed enrichment of stress related GOs in the up-regulated gene fractions, which included transcripts putatively involved in stomatal movements. This transcriptomic study has yielded promising candidate genes that merit further functional studies to confirm their involvement in drought tolerance and recovery. Together, our results contribute to a better understanding of the coordinated responses taking place under drought stress and recovery in adult plants of tomato. PMID:27066027

Transcriptome Profiling of the Abdominal Skin of Larimichthys crocea in Light Stress

NASA Astrophysics Data System (ADS)

Han, Zhaofang; Lv, Changhuan; Xiao, Shijun; Ye, Kun; Zhang, Dongling; Tsai, Huai Jen; Wang, Zhiyong

2018-04-01

Large yellow croaker ( Larimichthys crocea), one of the most important marine fish species in China, can change its abdominal skin color when it is shifted from light to dark or from dark to light, providing us an opportunity of investigating the molecular responding mechanism of teleost in light stress. The gene expression profile of fish under light stress is rarely documented. In this research, the transcriptome profiles of the abdominal skin of L. crocea exposed to light or dark for 0 h, 0.5 h and 2 h were produced by next-generation sequencing (NGS). The cluster results demonstrated that stress period, rather than light intensity ( e.g., light or dark), is the major influencing factor. Differently expressed genes (DEGs) were identified between 0 h and 0.5 h groups, between 0 h and 2 h groups, between 0.5 h light and 0.5 h dark, and between 2 h light and 2 h dark, respectively. The gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation revealed that the genes relating to immunity, energy metabolism, and cytoskeletal protein binding were significantly enriched. The detailed analysis of transcriptome profiles also revealed regular gene expression trends, indicating that the elaborate gene regulation networks underlined the molecular responses of the fish to light stress. This transcriptome analysis suggested that systematic and complicated regulatory cascades were functionally activated in response to external stress, and coloration change caused by light stress was mainly attributed to the change in the density of chromatophores for L. crocea. This study also provided valuable information for skin coloration or light stress research on other marine fish species.

Analysis of the Aspergillus flavus transcriptome reveals a key role of secondary metabolite production in isolate oxidative stress responses

USDA-ARS?s Scientific Manuscript database

The purpose of the production of secondary metabolites in fungi are various and include stress responses, competitive antimicrobial activity, and the elimination of toxic compounds. However, the purpose of the production of aflatoxin, a carcinogenic mycotoxin, by Aspergillus flavus, is unknown. Prev...

Comparative analysis of chrysanthemum transcriptome in response to three RNA viruses: Cucumber mosaic virus, Tomato spotted wilt virus and Potato virus X.

PubMed

Choi, Hoseong; Jo, Yeonhwa; Lian, Sen; Jo, Kyoung-Min; Chu, Hyosub; Yoon, Ju-Yeon; Choi, Seung-Kook; Kim, Kook-Hyung; Cho, Won Kyong

2015-06-01

The chrysanthemum is one of popular flowers in the world and a host for several viruses. So far, molecular interaction studies between the chrysanthemum and viruses are limited. In this study, we carried out a transcriptome analysis of chrysanthemum in response to three different viruses including Cucumber mosaic virus (CMV), Tomato spotted wilt virus (TSWV) and Potato virus X (PVX). A chrysanthemum 135K microarray derived from expressed sequence tags was successfully applied for the expression profiles of the chrysanthemum at early stage of virus infection. Finally, we identified a total of 125, 70 and 124 differentially expressed genes (DEGs) for CMV, TSWV and PVX, respectively. Many DEGs were virus specific; however, 33 DEGs were commonly regulated by three viruses. Gene ontology (GO) enrichment analysis identified a total of 132 GO terms, and of them, six GO terms related stress response and MCM complex were commonly identified for three viruses. Several genes functioning in stress response such as chitin response and ethylene mediated signaling pathway were up-regulated indicating their involvement in establishment of host immune system. In particular, TSWV infection significantly down-regulated genes related to DNA metabolic process including DNA replication, chromatin organization, histone modification and cytokinesis, and they are mostly targeted to nucleosome and MCM complex. Taken together, our comparative transcriptome analysis revealed several genes related to hormone mediated viral stress response and DNA modification. The identified chrysanthemums genes could be good candidates for further functional study associated with resistant to various plant viruses.

Transcriptomes of Eight Arabidopsis thaliana Accessions Reveal Core Conserved, Genotype- and Organ-Specific Responses to Flooding Stress1[OPEN

PubMed Central

van Veen, Hans; Vashisht, Divya; Akman, Melis; Girke, Thomas; Mustroph, Angelika; Reinen, Emilie; Kooiker, Maarten; van Tienderen, Peter; Voesenek, Laurentius A.C.J.

2016-01-01

Climate change has increased the frequency and severity of flooding events, with significant negative impact on agricultural productivity. These events often submerge plant aerial organs and roots, limiting growth and survival due to a severe reduction in light reactions and gas exchange necessary for photosynthesis and respiration, respectively. To distinguish molecular responses to the compound stress imposed by submergence, we investigated transcriptomic adjustments to darkness in air and under submerged conditions using eight Arabidopsis (Arabidopsis thaliana) accessions differing significantly in sensitivity to submergence. Evaluation of root and rosette transcriptomes revealed an early transcriptional and posttranscriptional response signature that was conserved primarily across genotypes, although flooding susceptibility-associated and genotype-specific responses also were uncovered. Posttranscriptional regulation encompassed darkness- and submergence-induced alternative splicing of transcripts from pathways involved in the alternative mobilization of energy reserves. The organ-specific transcriptome adjustments reflected the distinct physiological status of roots and shoots. Root-specific transcriptome changes included marked up-regulation of chloroplast-encoded photosynthesis and redox-related genes, whereas those of the rosette were related to the regulation of development and growth processes. We identified a novel set of tolerance genes, recognized mainly by quantitative differences. These included a transcriptome signature of more pronounced gluconeogenesis in tolerant accessions, a response that included stress-induced alternative splicing. This study provides organ-specific molecular resolution of genetic variation in submergence responses involving interactions between darkness and low-oxygen constraints of flooding stress and demonstrates that early transcriptome plasticity, including alternative splicing, is associated with the ability to cope with a compound environmental stress. PMID:27208254

Comparative Transcriptomes Analysis of Red- and White-Fleshed Apples in an F1 Population of Malus sieversii f. niedzwetzkyana Crossed with M. domestica ‘Fuji’

PubMed Central

Wang, Nan; Zheng, Yi; Duan, Naibin; Zhang, Zongying; Ji, Xiaohao; Jiang, Shenghui; Sun, Shasha; Yang, Long; Bai, Yang; Fei, Zhangjun; Chen, Xuesen

2015-01-01

Transcriptome profiles of the red- and white-fleshed apples in an F1 segregating population of Malus sieversii f.Niedzwetzkyana and M.domestica ‘Fuji’ were generated using the next-generation high-throughput RNA sequencing (RNA-Seq) technology and compared. A total of 114 differentially expressed genes (DEGs) were obtained, of which 88 were up-regulated and 26 were down-regulated in red-fleshed apples. The 88 up-regulated genes were enriched with those related to flavonoid biosynthetic process and stress responses. Further analysis identified 22 genes associated with flavonoid biosynthetic process and 68 genes that may be related to stress responses. Furthermore, the expression of 20 up-regulated candidate genes (10 related to flavonoid biosynthesis, two encoding MYB transcription factors and eight related to stress responses) and 10 down-regulated genes were validated by quantitative real-time PCR. After exploring the possible regulatory network, we speculated that flavonoid metabolism might be involved in stress responses in red-fleshed apple. Our findings provide a theoretical basis for further enriching gene resources associated with flavonoid synthesis and stress responses of fruit trees and for breeding elite apples with high flavonoid content and/or increased stress tolerances. PMID:26207813

Comparative Transcriptomes Analysis of Red- and White-Fleshed Apples in an F1 Population of Malus sieversii f. niedzwetzkyana Crossed with M. domestica 'Fuji'.

PubMed

Wang, Nan; Zheng, Yi; Duan, Naibin; Zhang, Zongying; Ji, Xiaohao; Jiang, Shenghui; Sun, Shasha; Yang, Long; Bai, Yang; Fei, Zhangjun; Chen, Xuesen

2015-01-01

Transcriptome profiles of the red- and white-fleshed apples in an F1 segregating population of Malus sieversii f.Niedzwetzkyana and M.domestica 'Fuji' were generated using the next-generation high-throughput RNA sequencing (RNA-Seq) technology and compared. A total of 114 differentially expressed genes (DEGs) were obtained, of which 88 were up-regulated and 26 were down-regulated in red-fleshed apples. The 88 up-regulated genes were enriched with those related to flavonoid biosynthetic process and stress responses. Further analysis identified 22 genes associated with flavonoid biosynthetic process and 68 genes that may be related to stress responses. Furthermore, the expression of 20 up-regulated candidate genes (10 related to flavonoid biosynthesis, two encoding MYB transcription factors and eight related to stress responses) and 10 down-regulated genes were validated by quantitative real-time PCR. After exploring the possible regulatory network, we speculated that flavonoid metabolism might be involved in stress responses in red-fleshed apple. Our findings provide a theoretical basis for further enriching gene resources associated with flavonoid synthesis and stress responses of fruit trees and for breeding elite apples with high flavonoid content and/or increased stress tolerances.

Microarray analysis and scale-free gene networks identify candidate regulators in drought-stressed roots of loblolly pine (P. taeda L.)

PubMed Central

2011-01-01

Background Global transcriptional analysis of loblolly pine (Pinus taeda L.) is challenging due to limited molecular tools. PtGen2, a 26,496 feature cDNA microarray, was fabricated and used to assess drought-induced gene expression in loblolly pine propagule roots. Statistical analysis of differential expression and weighted gene correlation network analysis were used to identify drought-responsive genes and further characterize the molecular basis of drought tolerance in loblolly pine. Results Microarrays were used to interrogate root cDNA populations obtained from 12 genotype × treatment combinations (four genotypes, three watering regimes). Comparison of drought-stressed roots with roots from the control treatment identified 2445 genes displaying at least a 1.5-fold expression difference (false discovery rate = 0.01). Genes commonly associated with drought response in pine and other plant species, as well as a number of abiotic and biotic stress-related genes, were up-regulated in drought-stressed roots. Only 76 genes were identified as differentially expressed in drought-recovered roots, indicating that the transcript population can return to the pre-drought state within 48 hours. Gene correlation analysis predicts a scale-free network topology and identifies eleven co-expression modules that ranged in size from 34 to 938 members. Network topological parameters identified a number of central nodes (hubs) including those with significant homology (E-values ≤ 2 × 10-30) to 9-cis-epoxycarotenoid dioxygenase, zeatin O-glucosyltransferase, and ABA-responsive protein. Identified hubs also include genes that have been associated previously with osmotic stress, phytohormones, enzymes that detoxify reactive oxygen species, and several genes of unknown function. Conclusion PtGen2 was used to evaluate transcriptome responses in loblolly pine and was leveraged to identify 2445 differentially expressed genes responding to severe drought stress in roots. Many of the genes identified are known to be up-regulated in response to osmotic stress in pine and other plant species and encode proteins involved in both signal transduction and stress tolerance. Gene expression levels returned to control values within a 48-hour recovery period in all but 76 transcripts. Correlation network analysis indicates a scale-free network topology for the pine root transcriptome and identifies central nodes that may serve as drivers of drought-responsive transcriptome dynamics in the roots of loblolly pine. PMID:21609476

Global insights into high temperature and drought stress regulated genes by RNA-Seq in economically important oilseed crop Brassica juncea.

PubMed

Bhardwaj, Ankur R; Joshi, Gopal; Kukreja, Bharti; Malik, Vidhi; Arora, Priyanka; Pandey, Ritu; Shukla, Rohit N; Bankar, Kiran G; Katiyar-Agarwal, Surekha; Goel, Shailendra; Jagannath, Arun; Kumar, Amar; Agarwal, Manu

2015-01-21

Brassica juncea var. Varuna is an economically important oilseed crop of family Brassicaceae which is vulnerable to abiotic stresses at specific stages in its life cycle. Till date no attempts have been made to elucidate genome-wide changes in its transcriptome against high temperature or drought stress. To gain global insights into genes, transcription factors and kinases regulated by these stresses and to explore information on coding transcripts that are associated with traits of agronomic importance, we utilized a combinatorial approach of next generation sequencing and de-novo assembly to discover B. juncea transcriptome associated with high temperature and drought stresses. We constructed and sequenced three transcriptome libraries namely Brassica control (BC), Brassica high temperature stress (BHS) and Brassica drought stress (BDS). More than 180 million purity filtered reads were generated which were processed through quality parameters and high quality reads were assembled de-novo using SOAPdenovo assembler. A total of 77750 unique transcripts were identified out of which 69,245 (89%) were annotated with high confidence. We established a subset of 19110 transcripts, which were differentially regulated by either high temperature and/or drought stress. Furthermore, 886 and 2834 transcripts that code for transcription factors and kinases, respectively, were also identified. Many of these were responsive to high temperature, drought or both stresses. Maximum number of up-regulated transcription factors in high temperature and drought stress belonged to heat shock factors (HSFs) and dehydration responsive element-binding (DREB) families, respectively. We also identified 239 metabolic pathways, which were perturbed during high temperature and drought treatments. Analysis of gene ontologies associated with differentially regulated genes forecasted their involvement in diverse biological processes. Our study provides first comprehensive discovery of B. juncea transcriptome under high temperature and drought stress conditions. Transcriptome resource generated in this study will enhance our understanding on the molecular mechanisms involved in defining the response of B. juncea against two important abiotic stresses. Furthermore this information would benefit designing of efficient crop improvement strategies for tolerance against conditions of high temperature regimes and water scarcity.

Linking the salt transcriptome with physiological responses of a salt-resistant Populus species as a strategy to identify genes important for stress acclimation.

PubMed

Brinker, Monika; Brosché, Mikael; Vinocur, Basia; Abo-Ogiala, Atef; Fayyaz, Payam; Janz, Dennis; Ottow, Eric A; Cullmann, Andreas D; Saborowski, Joachim; Kangasjärvi, Jaakko; Altman, Arie; Polle, Andrea

2010-12-01

To investigate early salt acclimation mechanisms in a salt-tolerant poplar species (Populus euphratica), the kinetics of molecular, metabolic, and physiological changes during a 24-h salt exposure were measured. Three distinct phases of salt stress were identified by analyses of the osmotic pressure and the shoot water potential: dehydration, salt accumulation, and osmotic restoration associated with ionic stress. The duration and intensity of these phases differed between leaves and roots. Transcriptome analysis using P. euphratica-specific microarrays revealed clusters of coexpressed genes in these phases, with only 3% overlapping salt-responsive genes in leaves and roots. Acclimation of cellular metabolism to high salt concentrations involved remodeling of amino acid and protein biosynthesis and increased expression of molecular chaperones (dehydrins, osmotin). Leaves suffered initially from dehydration, which resulted in changes in transcript levels of mitochondrial and photosynthetic genes, indicating adjustment of energy metabolism. Initially, decreases in stress-related genes were found, whereas increases occurred only when leaves had restored the osmotic balance by salt accumulation. Comparative in silico analysis of the poplar stress regulon with Arabidopsis (Arabidopsis thaliana) orthologs was used as a strategy to reduce the number of candidate genes for functional analysis. Analysis of Arabidopsis knockout lines identified a lipocalin-like gene (AtTIL) and a gene encoding a protein with previously unknown functions (AtSIS) to play roles in salt tolerance. In conclusion, by dissecting the stress transcriptome of tolerant species, novel genes important for salt endurance can be identified.

Linking the Salt Transcriptome with Physiological Responses of a Salt-Resistant Populus Species as a Strategy to Identify Genes Important for Stress Acclimation1[W][OA

PubMed Central

Brinker, Monika; Brosché, Mikael; Vinocur, Basia; Abo-Ogiala, Atef; Fayyaz, Payam; Janz, Dennis; Ottow, Eric A.; Cullmann, Andreas D.; Saborowski, Joachim; Kangasjärvi, Jaakko; Altman, Arie; Polle, Andrea

2010-01-01

To investigate early salt acclimation mechanisms in a salt-tolerant poplar species (Populus euphratica), the kinetics of molecular, metabolic, and physiological changes during a 24-h salt exposure were measured. Three distinct phases of salt stress were identified by analyses of the osmotic pressure and the shoot water potential: dehydration, salt accumulation, and osmotic restoration associated with ionic stress. The duration and intensity of these phases differed between leaves and roots. Transcriptome analysis using P. euphratica-specific microarrays revealed clusters of coexpressed genes in these phases, with only 3% overlapping salt-responsive genes in leaves and roots. Acclimation of cellular metabolism to high salt concentrations involved remodeling of amino acid and protein biosynthesis and increased expression of molecular chaperones (dehydrins, osmotin). Leaves suffered initially from dehydration, which resulted in changes in transcript levels of mitochondrial and photosynthetic genes, indicating adjustment of energy metabolism. Initially, decreases in stress-related genes were found, whereas increases occurred only when leaves had restored the osmotic balance by salt accumulation. Comparative in silico analysis of the poplar stress regulon with Arabidopsis (Arabidopsis thaliana) orthologs was used as a strategy to reduce the number of candidate genes for functional analysis. Analysis of Arabidopsis knockout lines identified a lipocalin-like gene (AtTIL) and a gene encoding a protein with previously unknown functions (AtSIS) to play roles in salt tolerance. In conclusion, by dissecting the stress transcriptome of tolerant species, novel genes important for salt endurance can be identified. PMID:20959419

Transcriptome Profiling of Shewanella oneidensis Gene Expression following Exposure to Acidic and Alkaline pH†

PubMed Central

Leaphart, Adam B.; Thompson, Dorothea K.; Huang, Katherine; Alm, Eric; Wan, Xiu-Feng; Arkin, Adam; Brown, Steven D.; Wu, Liyou; Yan, Tingfen; Liu, Xueduan; Wickham, Gene S.; Zhou, Jizhong

2006-01-01

The molecular response of Shewanella oneidensis MR-1 to variations in extracellular pH was investigated based on genomewide gene expression profiling. Microarray analysis revealed that cells elicited both general and specific transcriptome responses when challenged with environmental acid (pH 4) or base (pH 10) conditions over a 60-min period. Global responses included the differential expression of genes functionally linked to amino acid metabolism, transcriptional regulation and signal transduction, transport, cell membrane structure, and oxidative stress protection. Response to acid stress included the elevated expression of genes encoding glycogen biosynthetic enzymes, phosphate transporters, and the RNA polymerase sigma-38 factor (rpoS), whereas the molecular response to alkaline pH was characterized by upregulation of nhaA and nhaR, which are predicted to encode an Na+/H+ antiporter and transcriptional activator, respectively, as well as sulfate transport and sulfur metabolism genes. Collectively, these results suggest that S. oneidensis modulates multiple transporters, cell envelope components, and pathways of amino acid consumption and central intermediary metabolism as part of its transcriptome response to changing external pH conditions. PMID:16452448

Transcriptome analysis of hexaploid hulless oat in response to salinity stress

PubMed Central

Wu, Bin; Hu, Yani; Huo, Pengjie; Zhang, Qian; Chen, Xin; Zhang, Zongwen

2017-01-01

Background Oat is a cereal crop of global importance used for food, feed, and forage. Understanding salinity stress tolerance mechanisms in plants is an important step towards generating crop varieties that can cope with environmental stresses. To date, little is known about the salt tolerance of oat at the molecular level. To better understand the molecular mechanisms underlying salt tolerance in oat, we investigated the transcriptomes of control and salt-treated oat using RNA-Seq. Results Using Illumina HiSeq 4000 platform, we generated 72,291,032 and 356,891,432 reads from non-stressed control and salt-stressed oat, respectively. Assembly of 64 Gb raw sequence data yielded 128,414 putative unique transcripts with an average length of 1,189 bp. Analysis of the assembled unigenes from the salt stressed and control libraries indicated that about 65,000 unigenes were differentially expressed at different stages. Functional annotation showed that ABC transporters, plant hormone signal transduction, plant-pathogen interactions, starch and sucrose metabolism, arginine and proline metabolism, and other secondary metabolite pathways were enriched under salt stress. Based on the RPKM values of assembled unigenes, 24 differentially expressed genes under salt stress were selected for quantitative RT-PCR validation, which successfully confirmed the results of RNA-Seq. Furthermore, we identified 18,039 simple sequence repeats, which may help further elucidate salt tolerance mechanisms in oat. Conclusions Our global survey of transcriptome profiles of oat plants in response to salt stress provides useful insights into the molecular mechanisms underlying salt tolerance in this crop. These findings also represent a rich resource for further analysis of salt tolerance and for breeding oat with improved salt tolerance through the use of salt-related genes. PMID:28192458

RNA-Seq Transcriptome Profiling of Upland Cotton (Gossypium hirsutum L.) Root Tissue under Water-Deficit Stress

PubMed Central

Bowman, Megan J.; Park, Wonkeun; Bauer, Philip J.; Udall, Joshua A.; Page, Justin T.; Raney, Joshua; Scheffler, Brian E.; Jones, Don. C.; Campbell, B. Todd

2013-01-01

An RNA-Seq experiment was performed using field grown well-watered and naturally rain fed cotton plants to identify differentially expressed transcripts under water-deficit stress. Our work constitutes the first application of the newly published diploid D5 Gossypium raimondii sequence in the study of tetraploid AD1 upland cotton RNA-seq transcriptome analysis. A total of 1,530 transcripts were differentially expressed between well-watered and water-deficit stressed root tissues, in patterns that confirm the accuracy of this technique for future studies in cotton genomics. Additionally, putative sequence based genome localization of differentially expressed transcripts detected A2 genome specific gene expression under water-deficit stress. These data will facilitate efforts to understand the complex responses governing transcriptomic regulatory mechanisms and to identify candidate genes that may benefit applied plant breeding programs. PMID:24324815

The contribution of transcriptomic and proteomic analysis in elucidating stress adaptation responses of Listeria monocytogenes

USDA-ARS?s Scientific Manuscript database

The foodborne transmission of Listeria monocytogenes requires physiological adaptation to various conditions, including the cold, osmotic, heat, acid, alkaline, and oxidative stresses, associated with food hygiene, processing, and preservation measures. We review the current knowledge on the molecul...

Strain-Dependent Transcriptome Signatures for Robustness in Lactococcus lactis

PubMed Central

Dijkstra, Annereinou R.; Alkema, Wynand; Starrenburg, Marjo J. C.; van Hijum, Sacha A. F. T.; Bron, Peter A.

2016-01-01

Recently, we demonstrated that fermentation conditions have a strong impact on subsequent survival of Lactococcus lactis strain MG1363 during heat and oxidative stress, two important parameters during spray drying. Moreover, employment of a transcriptome-phenotype matching approach revealed groups of genes associated with robustness towards heat and/or oxidative stress. To investigate if other strains have similar or distinct transcriptome signatures for robustness, we applied an identical transcriptome-robustness phenotype matching approach on the L. lactis strains IL1403, KF147 and SK11, which have previously been demonstrated to display highly diverse robustness phenotypes. These strains were subjected to an identical fermentation regime as was performed earlier for strain MG1363 and consisted of twelve conditions, varying in the level of salt and/or oxygen, as well as fermentation temperature and pH. In the exponential phase of growth, cells were harvested for transcriptome analysis and assessment of heat and oxidative stress survival phenotypes. The variation in fermentation conditions resulted in differences in heat and oxidative stress survival of up to five 10-log units. Effects of the fermentation conditions on stress survival of the L. lactis strains were typically strain-dependent, although the fermentation conditions had mainly similar effects on the growth characteristics of the different strains. By association of the transcriptomes and robustness phenotypes highly strain-specific transcriptome signatures for robustness towards heat and oxidative stress were identified, indicating that multiple mechanisms exist to increase robustness and, as a consequence, robustness of each strain requires individual optimization. However, a relatively small overlap in the transcriptome responses of the strains was also identified and this generic transcriptome signature included genes previously associated with stress (ctsR and lplL) and novel genes, including nanE and genes encoding transport proteins. The transcript levels of these genes can function as indicators of robustness and could aid in selection of fermentation parameters, potentially resulting in more optimal robustness during spray drying. PMID:27973578

Transcriptome Analysis of Salt Stress Responsiveness in the Seedlings of Dongxiang Wild Rice (Oryza rufipogon Griff.).

PubMed

Zhou, Yi; Yang, Ping; Cui, Fenglei; Zhang, Fantao; Luo, Xiangdong; Xie, Jiankun

2016-01-01

Dongxiang wild rice (Oryza rufipogon Griff.) is the progenitor of cultivated rice (Oryza sativa L.), and is well known for its superior level of tolerance against cold, drought and diseases. To date, however, little is known about the salt-tolerant character of Dongxiang wild rice. To elucidate the molecular genetic mechanisms of salt-stress tolerance in Dongxiang wild rice, the Illumina HiSeq 2000 platform was used to analyze the transcriptome profiles of the leaves and roots at the seedling stage under salt stress compared with those under normal conditions. The analysis results for the sequencing data showed that 6,867 transcripts were differentially expressed in the leaves (2,216 up-regulated and 4,651 down-regulated) and 4,988 transcripts in the roots (3,105 up-regulated and 1,883 down-regulated). Among these differentially expressed genes, the detection of many transcription factor genes demonstrated that multiple regulatory pathways were involved in salt stress tolerance. In addition, the differentially expressed genes were compared with the previous RNA-Seq analysis of salt-stress responses in cultivated rice Nipponbare, indicating the possible specific molecular mechanisms of salt-stress responses for Dongxiang wild rice. A large number of the salt-inducible genes identified in this study were co-localized onto fine-mapped salt-tolerance-related quantitative trait loci, providing candidates for gene cloning and elucidation of molecular mechanisms responsible for salt-stress tolerance in rice.

Transcriptome Analysis of Salt Stress Responsiveness in the Seedlings of Dongxiang Wild Rice (Oryza rufipogon Griff.)

PubMed Central

Zhou, Yi; Yang, Ping; Cui, Fenglei; Zhang, Fantao; Luo, Xiangdong; Xie, Jiankun

2016-01-01

Dongxiang wild rice (Oryza rufipogon Griff.) is the progenitor of cultivated rice (Oryza sativa L.), and is well known for its superior level of tolerance against cold, drought and diseases. To date, however, little is known about the salt-tolerant character of Dongxiang wild rice. To elucidate the molecular genetic mechanisms of salt-stress tolerance in Dongxiang wild rice, the Illumina HiSeq 2000 platform was used to analyze the transcriptome profiles of the leaves and roots at the seedling stage under salt stress compared with those under normal conditions. The analysis results for the sequencing data showed that 6,867 transcripts were differentially expressed in the leaves (2,216 up-regulated and 4,651 down-regulated) and 4,988 transcripts in the roots (3,105 up-regulated and 1,883 down-regulated). Among these differentially expressed genes, the detection of many transcription factor genes demonstrated that multiple regulatory pathways were involved in salt stress tolerance. In addition, the differentially expressed genes were compared with the previous RNA-Seq analysis of salt-stress responses in cultivated rice Nipponbare, indicating the possible specific molecular mechanisms of salt-stress responses for Dongxiang wild rice. A large number of the salt-inducible genes identified in this study were co-localized onto fine-mapped salt-tolerance-related quantitative trait loci, providing candidates for gene cloning and elucidation of molecular mechanisms responsible for salt-stress tolerance in rice. PMID:26752408

Comparative Transcriptomic Analysis of the Response to Cold Acclimation in Eucalyptus dunnii

PubMed Central

Liu, Yiqing; Jiang, Yusong; Lan, Jianbin; Zou, Yong; Gao, Junping

2014-01-01

Eucalyptus dunnii is an important macrophanerophyte with high economic value. However, low temperature stress limits its productivity and distribution. To study the cold response mechanisms of E. dunnii, 5 cDNA libraries were constructed from mRNA extracted from leaves exposed to cold stress for varying lengths of time and were evaluated by RNA-Seq analysis. The assembly of the Illumina datasets was optimized using various assembly programs and parameters. The final optimized assembly generated 205,325 transcripts with an average length of 1,701 bp and N50 of 2,627 bp, representing 349.38 Mb of the E. dunnii transcriptome. Among these transcripts, 134,358 transcripts (65.4%) were annotated in the Nr database. According to the differential analysis results, most transcripts were up-regulated as the cold stress prolonging, suggesting that these transcripts may be involved in the response to cold stress. In addition, the cold-relevant GO categories, such as ‘response to stress’ and ‘translational initiation’, were the markedly enriched GO terms. The assembly of the E. dunnii gene index and the GO classification performed in this study will serve as useful genomic resources for the genetic improvement of E. dunnii and also provide insights into the molecular mechanisms of cold acclimation in E. dunnii. PMID:25412179

Investigating the underlying mechanism of Saccharomyces cerevisiae in response to ethanol stress employing RNA-seq analysis.

PubMed

Li, Ruoyun; Xiong, Guotong; Yuan, Shukun; Wu, Zufang; Miao, Yingjie; Weng, Peifang

2017-11-03

Saccharomyces cerevisiae has been widely used for wine fermentation and bio-fuels production. A S. cerevisiae strain Sc131 isolated from tropical fruit shows good fermentation properties and ethanol tolerance, exhibiting significant potential in Chinese bayberry wine fermentation. In this study, RNA-sequence and RT-qPCR was used to investigate the transcriptome profile of Sc131 in response to ethanol stress. Scanning Electron Microscopy were carried out to observe surface morphology of yeast cells. Totally, 937 genes were identified differential expressed, including 587 up-regulated and 350 down-regulated genes, after 4-h ethanol stress (10% v/v). Transcriptomic analysis revealed that, most genes involved in regulating filamentous growth or pseudohyphal growth were significantly up-regulated in response to ethanol stress. The complex protein quality control machineries, Hsp90/Hsp70 and Hsp104/Hsp70/Hsp40 based chaperone system combining with ubiquitin-proteasome proteolytic pathway were both activated to recognize and degrade misfolding proteins. Genes related to biosynthesis and metabolism of two well-known stress-responsive substances trehalose and ergosterol were generally up-regulated, while genes associated with amino acids biosynthesis and metabolism processes were differentially expressed. Moreover, thiamine was also important in response to ethanol stress. This research may promote the potential applications of Sc131 in the fermentation of Chinese bayberry wine.

Transcriptome Analysis Reveals Genes Commonly Induced by Botrytis cinerea Infection, Cold, Drought and Oxidative Stresses in Arabidopsis

PubMed Central

Al-Ameri, Salma; Al-Mahmoud, Bassam; Awwad, Falah; Al-Rawashdeh, Ahmed; Iratni, Rabah; AbuQamar, Synan

2014-01-01

Signaling pathways controlling biotic and abiotic stress responses may interact synergistically or antagonistically. To identify the similarities and differences among responses to diverse stresses, we analyzed previously published microarray data on the transcriptomic responses of Arabidopsis to infection with Botrytis cinerea (a biotic stress), and to cold, drought, and oxidative stresses (abiotic stresses). Our analyses showed that at early stages after B. cinerea inoculation, 1498 genes were up-regulated (B. cinerea up-regulated genes; BUGs) and 1138 genes were down-regulated (B. cinerea down-regulated genes; BDGs). We showed a unique program of gene expression was activated in response each biotic and abiotic stress, but that some genes were similarly induced or repressed by all of the tested stresses. Of the identified BUGs, 25%, 6% and 12% were also induced by cold, drought and oxidative stress, respectively; whereas 33%, 7% and 5.5% of the BDGs were also down-regulated by the same abiotic stresses. Coexpression and protein-protein interaction network analyses revealed a dynamic range in the expression levels of genes encoding regulatory proteins. Analysis of gene expression in response to electrophilic oxylipins suggested that these compounds are involved in mediating responses to B. cinerea infection and abiotic stress through TGA transcription factors. Our results suggest an overlap among genes involved in the responses to biotic and abiotic stresses in Arabidopsis. Changes in the transcript levels of genes encoding components of the cyclopentenone signaling pathway in response to biotic and abiotic stresses suggest that the oxylipin signal transduction pathway plays a role in plant defense. Identifying genes that are commonly expressed in response to environmental stresses, and further analyzing the functions of their encoded products, will increase our understanding of the plant stress response. This information could identify targets for genetic modification to improve plant resistance to multiple stresses. PMID:25422934

Transcriptome sequencing and whole genome expression profiling of chrysanthemum under dehydration stress

PubMed Central

2013-01-01

Background Chrysanthemum is one of the most important ornamental crops in the world and drought stress seriously limits its production and distribution. In order to generate a functional genomics resource and obtain a deeper understanding of the molecular mechanisms regarding chrysanthemum responses to dehydration stress, we performed large-scale transcriptome sequencing of chrysanthemum plants under dehydration stress using the Illumina sequencing technology. Results Two cDNA libraries constructed from mRNAs of control and dehydration-treated seedlings were sequenced by Illumina technology. A total of more than 100 million reads were generated and de novo assembled into 98,180 unique transcripts which were further extensively annotated by comparing their sequencing to different protein databases. Biochemical pathways were predicted from these transcript sequences. Furthermore, we performed gene expression profiling analysis upon dehydration treatment in chrysanthemum and identified 8,558 dehydration-responsive unique transcripts, including 307 transcription factors and 229 protein kinases and many well-known stress responsive genes. Gene ontology (GO) term enrichment and biochemical pathway analyses showed that dehydration stress caused changes in hormone response, secondary and amino acid metabolism, and light and photoperiod response. These findings suggest that drought tolerance of chrysanthemum plants may be related to the regulation of hormone biosynthesis and signaling, reduction of oxidative damage, stabilization of cell proteins and structures, and maintenance of energy and carbon supply. Conclusions Our transcriptome sequences can provide a valuable resource for chrysanthemum breeding and research and novel insights into chrysanthemum responses to dehydration stress and offer candidate genes or markers that can be used to guide future studies attempting to breed drought tolerant chrysanthemum cultivars. PMID:24074255

Transcriptome Profiling of Watermelon Root in Response to Short-Term Osmotic Stress

PubMed Central

Yang, Yongchao; Mo, Yanling; Yang, Xiaozheng; Zhang, Haifei; Wang, Yongqi; Li, Hao; Wei, Chunhua; Zhang, Xian

2016-01-01

Osmotic stress adversely affects the growth, fruit quality and yield of watermelon (Citrullus lanatus (Thunb.) Matsum. & Nakai). Increasing the tolerance of watermelon to osmotic stress caused by factors such as high salt and water deficit is an effective way to improve crop survival in osmotic stress environments. Roots are important organs in water absorption and are involved in the initial response to osmosis stress; however, few studies have examined the underlying mechanism of tolerance to osmotic stress in watermelon roots. For better understanding of this mechanism, the inbred watermelon accession M08, which exhibits relatively high tolerance to water deficits, was treated with 20% polyethylene glycol (PEG) 6000. The root samples were harvested at 6 h after PEG treatment and untreated samples were used as controls. Transcriptome analyses were carried out by Illumina RNA sequencing. A total of 5246 differentially expressed genes were identified. Gene ontology enrichment and biochemical pathway analyses of these 5246 genes showed that short-term osmotic stress affected osmotic adjustment, signal transduction, hormone responses, cell division, cell cycle and ribosome, and M08 may repress root growth to adapt osmotic stress. The results of this study describe the watermelon root transcriptome under osmotic stress and propose new insight into watermelon root responses to osmotic stress at the transcriptome level. Accordingly, these results allow us to better understand the molecular mechanisms of watermelon in response to drought stress and will facilitate watermelon breeding projects to improve drought tolerance. PMID:27861528

Comparative transcriptome and gene co-expression network analysis reveal genes and signaling pathways adaptively responsive to varied adverse stresses in the insect fungal pathogen, Beauveria bassiana.

PubMed

He, Zhangjiang; Zhao, Xin; Lu, Zhuoyue; Wang, Huifang; Liu, Pengfei; Zeng, Fanqin; Zhang, Yongjun

2018-01-01

Sensing, responding, and adapting to the surrounding environment are crucial for all living organisms to survive, proliferate, and differentiate in their biological niches. Beauveria bassiana is an economically important insect-pathogenic fungus which is widely used as a biocontrol agent to control a variety of insect pests. The fungal pathogen unavoidably encounters a variety of adverse environmental stresses and defense response from the host insects during application of the fungal agents. However, few are known about the transcription response of the fungus to respond or adapt varied adverse stresses. Here, we comparatively analyzed the transcriptome of B. bassiana in globe genome under the varied stationary-phase stresses including osmotic agent (0.8 M NaCl), high temperature (32 °C), cell wall-perturbing agent (Congo red), and oxidative agents (H 2 O 2 or menadione). Total of 12,412 reads were obtained, and mapped to the 6767 genes of the B. bassiana. All of these stresses caused transcription responses involved in basal metabolism, cell wall construction, stress response or cell rescue/detoxification, signaling transduction and gene transcription regulation, and likely other cellular processes. An array of genes displayed similar transcription patterns in response to at least two of the five stresses, suggesting a shared transcription response to varied adverse stresses. Gene co-expression network analysis revealed that mTOR signaling pathway, but not HOG1 MAP kinase pathway, played a central role in regulation the varied adverse stress responses, which was verified by RNAi-mediated knockdown of TOR1. Our findings provided an insight of transcription response and gene co-expression network of B. bassiana in adaptation to varied environments. Copyright © 2017 Elsevier Inc. All rights reserved.

Characterizing the stress/defense transcriptome of Arabidopsis

PubMed Central

Mahalingam, Ramamurthy; Gomez-Buitrago, AnaMaria; Eckardt, Nancy; Shah, Nigam; Guevara-Garcia, Angel; Day, Philip; Raina, Ramesh; Fedoroff, Nina V

2003-01-01

Background To understand the gene networks that underlie plant stress and defense responses, it is necessary to identify and characterize the genes that respond both initially and as the physiological response to the stress or pathogen develops. We used PCR-based suppression subtractive hybridization to identify Arabidopsis genes that are differentially expressed in response to ozone, bacterial and oomycete pathogens and the signaling molecules salicylic acid (SA) and jasmonic acid. Results We identified a total of 1,058 differentially expressed genes from eight stress cDNA libraries. Digital northern analysis revealed that 55% of the stress-inducible genes are rarely transcribed in unstressed plants and 17% of them were not previously represented in Arabidopsis expressed sequence tag databases. More than two-thirds of the genes in the stress cDNA collection have not been identified in previous studies as stress/defense response genes. Several stress-responsive cis-elements showed a statistically significant over-representation in the promoters of the genes in the stress cDNA collection. These include W- and G-boxes, the SA-inducible element, the abscisic acid response element and the TGA motif. Conclusions The stress cDNA collection comprises a broad repertoire of stress-responsive genes encoding proteins that are involved in both the initial and subsequent stages of the physiological response to abiotic stress and pathogens. This set of stress-, pathogen- and hormone-modulated genes is an important resource for understanding the genetic interactions underlying stress signaling and responses and may contribute to the characterization of the stress transcriptome through the construction of standardized specialized arrays. PMID:12620105

Transcriptome analysis of Aspergillus flavus reveals isolate specific gene profiles in the response to oxidative stresses and carbon sources in vitro

USDA-ARS?s Scientific Manuscript database

Aflatoxin contamination of peanut and maize is exacerbated by drought stress. Reactive oxygen species (ROS) are produced in host plants during drought/heat stress, and are hypothesized to stimulate aflatoxin production. In order to better understand why Aspergillus flavus produces aflatoxin and the ...

Global transcriptome analysis of grapevine (Vitis vinifera L.) leaves under salt stress reveals differential response at early and late stages of stress in table grape cv. Thompson Seedless.

PubMed

Upadhyay, Anuradha; Gaonkar, Tulsi; Upadhyay, Ajay Kumar; Jogaiah, Satisha; Shinde, Manisha P; Kadoo, Narendra Y; Gupta, Vidya S

2018-05-31

Among the different abiotic stresses, salt stress has a significant effect on the growth and yield of grapevine (Vitis vinifera L.). In this study, we employed RNA sequence based transcriptome analysis to study salinity stress response in grape variety Thompson Seedless. Salt stress adversely affected the growth related and physiological parameters and the effect on physiological parameters was significant within 10 days of stress imposition. A total of 343 genes were differentially expressed in response to salt stress. Among the differentially expressed genes (DEGs) only 42 genes were common at early and late stages of stress. The gene enrichment analysis revealed that GO terms related to transcription factors were over-represented. Among the DEGs, 52 were transcription factors belonging to WRKY, EREB, MYB, NAC and bHLH families. Salt stress significantly affected several pathways like metabolic pathways, biosynthesis of secondary metabolites, membrane transport development related pathways etc. 343 DEGs were distributed on all the 19 chromosomes, however clustered regions of DEGs were present on chromosomes 2, 5, 6 and 12 suggesting probable QTLs for imparting tolerance to salt and other abiotic stresses. Real-time PCR of selected genes in control and treated samples of grafted and own root vines demonstrated that rootstock influenced expression of salt stress responsive genes. Microsatellite regions were identified in ten selected salt responsive genes and highly polymorphic markers were identified using fifteen grape genotypes. This information will be useful for the identification of key genes involved in salt stress tolerance in grape. The identified DEGs could also be useful for genome wide analysis for the identification of polymorphic markers for their subsequent use in molecular breeding for developing salt tolerant grape genotypes. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Transcriptome analysis of nitric oxide-responsive genes in upland cotton (Gossypium hirsutum).

PubMed

Huang, Juan; Wei, Hengling; Li, Libei; Yu, Shuxun

2018-01-01

Nitric oxide (NO) is an important signaling molecule with diverse physiological functions in plants. It is therefore important to characterize the downstream genes and signal transduction networks modulated by NO. Here, we identified 1,932 differentially expressed genes (DEGs) responding to NO in upland cotton using high throughput tag sequencing. The results of quantitative real-time polymerase chain reaction (qRT-PCR) analysis of 25 DEGs showed good consistency. Gene Ontology (GO) and KEGG pathway were analyzed to gain a better understanding of these DEGs. We identified 157 DEGs belonging to 36 transcription factor (TF) families and 72 DEGs related to eight plant hormones, among which several TF families and hormones were involved in stress responses. Hydrogen peroxide and malondialdehyde (MDA) contents were increased, as well related genes after treatment with sodium nitroprusside (SNP) (an NO donor), suggesting a role for NO in the plant stress response. Finally, we compared of the current and previous data indicating a massive number of NO-responsive genes at the large-scale transcriptome level. This study evaluated the landscape of NO-responsive genes in cotton and identified the involvement of NO in the stress response. Some of the identified DEGs represent good candidates for further functional analysis in cotton.

Transcriptome analysis of intraspecific competition in Arabidopsis thaliana reveals organ-specific signatures related to nutrient acquisition and general stress response pathways

PubMed Central

2012-01-01

Background Plants are sessile and therefore have to perceive and adjust to changes in their environment. The presence of neighbours leads to a competitive situation where resources and space will be limited. Complex adaptive responses to such situation are poorly understood at the molecular level. Results Using microarrays, we analysed whole-genome expression changes in Arabidopsis thaliana plants subjected to intraspecific competition. The leaf and root transcriptome was strongly altered by competition. Differentially expressed genes were enriched in genes involved in nutrient deficiency (mainly N, P, K), perception of light quality, and responses to abiotic and biotic stresses. Interestingly, performance of the generalist insect Spodoptera littoralis on densely grown plants was significantly reduced, suggesting that plants under competition display enhanced resistance to herbivory. Conclusions This study provides a comprehensive list of genes whose expression is affected by intraspecific competition in Arabidopsis. The outcome is a unique response that involves genes related to light, nutrient deficiency, abiotic stress, and defence responses. PMID:23194435

OsNucleolin1-L Expression in Arabidopsis Enhances Photosynthesis via Transcriptome Modification under Salt Stress Conditions.

PubMed

Udomchalothorn, Thanikarn; Plaimas, Kitiporn; Sripinyowanich, Siriporn; Boonchai, Chutamas; Kojonna, Thammaporn; Chutimanukul, Panita; Comai, Luca; Buaboocha, Teerapong; Chadchawan, Supachitra

2017-04-01

OsNUC1 encodes rice nucleolin, which has been shown to be involved in salt stress responses. Expression of the full-length OsNUC1 gene in Arabidopsis resulted in hypersensitivity to ABA during germination. Transcriptome analysis of the transgenic lines, in comparison with the wild type, revealed that the RNA abundance of >1,900 genes was significantly changed under normal growth conditions, while under salt stress conditions the RNAs of 999 genes were found to be significantly regulated. Gene enrichment analysis showed that under normal conditions OsNUC1 resulted in repression of genes involved in photosynthesis, while in salt stress conditions OsNUC1 increased expression of the genes involved in the light-harvesting complex. Correspondingly, the net rate of photosynthesis of the transgenic lines was increased under salt stress. Transgenic rice lines with overexpression of the OsNUC1-L gene were generated and tested for photosynthetic performance under salt stress conditions. The transgenic rice lines treated with salt stress at the booting stage had a higher photosynthetic rate and stomatal conductance in flag leaves and second leaves than the wild type. Moreover, higher contents of Chl a and carotenoids were found in flag leaves of the transgenic rice. These results suggest a role for OsNUC1 in the modification of the transcriptome, especially the gene transcripts responsible for photosynthesis, leading to stabilization of photosynthesis under salt stress conditions. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Transcriptome profiling of low temperature-treated cassava apical shoots showed dynamic responses of tropical plant to cold stress

PubMed Central

2012-01-01

Background Cassava is an important tropical root crop adapted to a wide range of environmental stimuli such as drought and acid soils. Nevertheless, it is an extremely cold-sensitive tropical species. Thus far, there is limited information about gene regulation and signalling pathways related to the cold stress response in cassava. The development of microarray technology has accelerated the study of global transcription profiling under certain conditions. Results A 60-mer oligonucleotide microarray representing 20,840 genes was used to perform transcriptome profiling in apical shoots of cassava subjected to cold at 7°C for 0, 4 and 9 h. A total of 508 transcripts were identified as early cold-responsive genes in which 319 sequences had functional descriptions when aligned with Arabidopsis proteins. Gene ontology annotation analysis identified many cold-relevant categories, including 'Response to abiotic and biotic stimulus', 'Response to stress', 'Transcription factor activity', and 'Chloroplast'. Various stress-associated genes with a wide range of biological functions were found, such as signal transduction components (e.g., MAP kinase 4), transcription factors (TFs, e.g., RAP2.11), and reactive oxygen species (ROS) scavenging enzymes (e.g., catalase 2), as well as photosynthesis-related genes (e.g., PsaL). Seventeen major TF families including many well-studied members (e.g., AP2-EREBP) were also involved in the early response to cold stress. Meanwhile, KEGG pathway analysis uncovered many important pathways, such as 'Plant hormone signal transduction' and 'Starch and sucrose metabolism'. Furthermore, the expression changes of 32 genes under cold and other abiotic stress conditions were validated by real-time RT-PCR. Importantly, most of the tested stress-responsive genes were primarily expressed in mature leaves, stem cambia, and fibrous roots rather than apical buds and young leaves. As a response to cold stress in cassava, an increase in transcripts and enzyme activities of ROS scavenging genes and the accumulation of total soluble sugars (including sucrose and glucose) were also detected. Conclusions The dynamic expression changes reflect the integrative controlling and transcriptome regulation of the networks in the cold stress response of cassava. The biological processes involved in the signal perception and physiological response might shed light on the molecular mechanisms related to cold tolerance in tropical plants and provide useful candidate genes for genetic improvement. PMID:22321773

Genomic adaptations of the halophilic Dead Sea filamentous fungus Eurotium rubrum.

PubMed

Kis-Papo, Tamar; Weig, Alfons R; Riley, Robert; Peršoh, Derek; Salamov, Asaf; Sun, Hui; Lipzen, Anna; Wasser, Solomon P; Rambold, Gerhard; Grigoriev, Igor V; Nevo, Eviatar

2014-05-09

The Dead Sea is one of the most hypersaline habitats on Earth. The fungus Eurotium rubrum (Eurotiomycetes) is among the few species able to survive there. Here we highlight its adaptive strategies, based on genome analysis and transcriptome profiling. The 26.2 Mb genome of E. rubrum shows, for example, gains in gene families related to stress response and losses with regard to transport processes. Transcriptome analyses under different salt growth conditions revealed, among other things differentially expressed genes encoding ion and metabolite transporters. Our findings suggest that long-term adaptation to salinity requires cellular and metabolic responses that differ from short-term osmotic stress signalling. The transcriptional response indicates that halophilic E. rubrum actively counteracts the salinity stress. Many of its genes encode for proteins with a significantly higher proportion of acidic amino acid residues. This trait is characteristic of the halophilic prokaryotes as well, supporting the theory of convergent evolution under extreme hypersaline stress.

Transcriptome profiling and physiological studies reveal a major role for aromatic amino acids in mercury stress tolerance in rice seedlings.

PubMed

Chen, Yun-An; Chi, Wen-Chang; Trinh, Ngoc Nam; Huang, Li-Yao; Chen, Ying-Chih; Cheng, Kai-Teng; Huang, Tsai-Lien; Lin, Chung-Yi; Huang, Hao-Jen

2014-01-01

Mercury (Hg) is a serious environmental pollution threat to the planet. The accumulation of Hg in plants disrupts many cellular-level functions and inhibits growth and development, but the mechanism is not fully understood. To gain more insight into the cellular response to Hg, we performed a large-scale analysis of the rice transcriptome during Hg stress. Genes induced with short-term exposure represented functional categories of cell-wall formation, chemical detoxification, secondary metabolism, signal transduction and abiotic stress response. Moreover, Hg stress upregulated several genes involved in aromatic amino acids (Phe and Trp) and increased the level of free Phe and Trp content. Exogenous application of Phe and Trp to rice roots enhanced tolerance to Hg and effectively reduced Hg-induced production of reactive oxygen species. Hg induced calcium accumulation and activated mitogen-activated protein kinase. Further characterization of the Hg-responsive genes we identified may be helpful for better understanding the mechanisms of Hg in plants.

Transcriptional Profiling of Mycobacterium tuberculosis Exposed to In Vitro Lysosomal Stress

PubMed Central

Lin, Wenwei; de Sessions, Paola Florez; Teoh, Garrett Hor Keong; Mohamed, Ahmad Naim Nazri; Zhu, Yuan O.; Koh, Vanessa Hui Qi; Ang, Michelle Lay Teng; Dedon, Peter C.; Hibberd, Martin Lloyd

2016-01-01

Increasing experimental evidence supports the idea that Mycobacterium tuberculosis has evolved strategies to survive within lysosomes of activated macrophages. To further our knowledge of M. tuberculosis response to the hostile lysosomal environment, we profiled the global transcriptional activity of M. tuberculosis when exposed to the lysosomal soluble fraction (SF) prepared from activated macrophages. Transcriptome sequencing (RNA-seq) analysis was performed using various incubation conditions, ranging from noninhibitory to cidal based on the mycobacterial replication or killing profile. Under inhibitory conditions that led to the absence of apparent mycobacterial replication, M. tuberculosis expressed a unique transcriptome with modulation of genes involved in general stress response, metabolic reprogramming, respiration, oxidative stress, dormancy response, and virulence. The transcription pattern also indicates characteristic cell wall remodeling with the possible outcomes of increased infectivity, intrinsic resistance to antibiotics, and subversion of the host immune system. Among the lysosome-specific responses, we identified the glgE-mediated 1,4 α-glucan synthesis pathway and a defined group of VapBC toxin/anti-toxin systems, both of which represent toxicity mechanisms that potentially can be exploited for killing intracellular mycobacteria. A meta-analysis including previously reported transcriptomic studies in macrophage infection and in vitro stress models was conducted to identify overlapping and nonoverlapping pathways. Finally, the Tap efflux pump-encoding gene Rv1258c was selected for validation. An M. tuberculosis ΔRv1258c mutant was constructed and displayed increased susceptibility to killing by lysosomal SF and the antimicrobial peptide LL-37, as well as attenuated survival in primary murine macrophages and human macrophage cell line THP-1. PMID:27324481

Comparative transcriptomics and proteomics analysis of citrus fruit, to improve understanding of the effect of low temperature on maintaining fruit quality during lengthy post-harvest storage

PubMed Central

Yun, Ze; Jin, Shuai; Ding, Yuduan; Wang, Zhuang; Gao, Huijun; Pan, Zhiyong; Xu, Juan; Cheng, Yunjiang; Deng, Xiuxin

2012-01-01

Fruit quality is a very complex trait that is affected by both genetic and non-genetic factors. Generally, low temperature (LT) is used to delay fruit senescence and maintain fruit quality during post-harvest storage but the molecular mechanisms involved are poorly understood. Hirado Buntan Pummelo (HBP; Citrus grandis × C. paradis) fruit were chosen to explore the mechanisms that maintain citrus fruit quality during lengthy LT storage using transcriptome and proteome studies based on digital gene expression (DGE) profiling and two-dimensional gel electrophoresis (2-DE), respectively. Results showed that LT up-regulated stress-responsive genes, arrested signal transduction, and inhibited primary metabolism, secondary metabolism and the transportation of metabolites. Calcineurin B-like protein (CBL)–CBL-interacting protein kinase complexes might be involved in the signal transduction of LT stress, and fruit quality is likely to be regulated by sugar-mediated auxin and abscisic acid (ABA) signalling. Furthermore, ABA was specific to the regulation of citrus fruit senescence and was not involved in the LT stress response. In addition, the accumulation of limonin, nomilin, methanol, and aldehyde, together with the up-regulated heat shock proteins, COR15, and cold response-related genes, provided a comprehensive proteomics and transcriptomics view on the coordination of fruit LT stress responses. PMID:22323274

Machine Learning–Based Differential Network Analysis: A Study of Stress-Responsive Transcriptomes in Arabidopsis[W

PubMed Central

Ma, Chuang; Xin, Mingming; Feldmann, Kenneth A.; Wang, Xiangfeng

2014-01-01

Machine learning (ML) is an intelligent data mining technique that builds a prediction model based on the learning of prior knowledge to recognize patterns in large-scale data sets. We present an ML-based methodology for transcriptome analysis via comparison of gene coexpression networks, implemented as an R package called machine learning–based differential network analysis (mlDNA) and apply this method to reanalyze a set of abiotic stress expression data in Arabidopsis thaliana. The mlDNA first used a ML-based filtering process to remove nonexpressed, constitutively expressed, or non-stress-responsive “noninformative” genes prior to network construction, through learning the patterns of 32 expression characteristics of known stress-related genes. The retained “informative” genes were subsequently analyzed by ML-based network comparison to predict candidate stress-related genes showing expression and network differences between control and stress networks, based on 33 network topological characteristics. Comparative evaluation of the network-centric and gene-centric analytic methods showed that mlDNA substantially outperformed traditional statistical testing–based differential expression analysis at identifying stress-related genes, with markedly improved prediction accuracy. To experimentally validate the mlDNA predictions, we selected 89 candidates out of the 1784 predicted salt stress–related genes with available SALK T-DNA mutagenesis lines for phenotypic screening and identified two previously unreported genes, mutants of which showed salt-sensitive phenotypes. PMID:24520154

Divergence in Morris Water Maze-Based Cognitive Performance under Chronic Stress Is Associated with the Hippocampal Whole Transcriptomic Modification in Mice

PubMed Central

Jung, Seung H.; Brownlow, Milene L.; Pellegrini, Matteo; Jankord, Ryan

2017-01-01

Individual susceptibility determines the magnitude of stress effects on cognitive function. The hippocampus, a brain region of memory consolidation, is vulnerable to stressful environments, and the impact of stress on hippocampus may determine individual variability in cognitive performance. Therefore, the purpose of this study was to define the relationship between the divergence in spatial memory performance under chronically unpredictable stress and an associated transcriptomic alternation in hippocampus, the brain region of spatial memory consolidation. Multiple strains of BXD (B6 × D2) recombinant inbred mice went through a 4-week chronic variable stress (CVS) paradigm, and the Morris water maze (MWM) test was conducted during the last week of CVS to assess hippocampal-dependent spatial memory performance and grouped animals into low and high performing groups based on the cognitive performance. Using hippocampal whole transcriptome RNA-sequencing data, differential expression, PANTHER analysis, WGCNA, Ingenuity's upstream regulator analysis in the Ingenuity Pathway Analysis® and phenotype association analysis were conducted. Our data identified multiple genes and pathways that were significantly associated with chronic stress-associated cognitive modification and the divergence in hippocampal dependent memory performance under chronic stress. Biological pathways associated with memory performance following chronic stress included metabolism, neurotransmitter and receptor regulation, immune response and cellular process. The Ingenuity's upstream regulator analysis identified 247 upstream transcriptional regulators from 16 different molecule types. Transcripts predictive of cognitive performance under high stress included genes that are associated with a high occurrence of Alzheimer's and cognitive impairments (e.g., Ncl, Eno1, Scn9a, Slc19a3, Ncstn, Fos, Eif4h, Copa, etc.). Our results show that the variable effects of chronic stress on the hippocampal transcriptome are related to the ability to complete the MWM task and that the modulations of specific pathways are indicative of hippocampal dependent memory performance. Thus, the divergence in spatial memory performance following chronic stress is related to the unique pattern of gene expression within the hippocampus. PMID:28912681

Transcriptome Profiling of Radish (Raphanus sativus L.) Root and Identification of Genes Involved in Response to Lead (Pb) Stress with Next Generation Sequencing

PubMed Central

Wang, Yan; Xu, Liang; Chen, Yinglong; Shen, Hong; Gong, Yiqin; Limera, Cecilia; Liu, Liwang

2013-01-01

Lead (Pb), one of the most toxic heavy metals, can be absorbed and accumulated by plant roots and then enter the food chain resulting in potential health risks for human beings. The radish (Raphanus sativus L.) is an important root vegetable crop with fleshy taproots as the edible parts. Little is known about the mechanism by which radishes respond to Pb stress at the molecular level. In this study, Next Generation Sequencing (NGS)–based RNA-seq technology was employed to characterize the de novo transcriptome of radish roots and identify differentially expressed genes (DEGs) during Pb stress. A total of 68,940 assembled unique transcripts including 33,337 unigenes were obtained from radish root cDNA samples. Based on the assembled de novo transcriptome, 4,614 DEGs were detected between the two libraries of untreated (CK) and Pb-treated (Pb1000) roots. Gene Ontology (GO) and pathway enrichment analysis revealed that upregulated DEGs under Pb stress are predominately involved in defense responses in cell walls and glutathione metabolism-related processes, while downregulated DEGs were mainly involved in carbohydrate metabolism-related pathways. The expression patterns of 22 selected genes were validated by quantitative real-time PCR, and the results were highly accordant with the Solexa analysis. Furthermore, many candidate genes, which were involved in defense and detoxification mechanisms including signaling protein kinases, transcription factors, metal transporters and chelate compound biosynthesis related enzymes, were successfully identified in response to heavy metal Pb. Identification of potential DEGs involved in responses to Pb stress significantly reflected alterations in major biological processes and metabolic pathways. The molecular basis of the response to Pb stress in radishes was comprehensively characterized. Useful information and new insights were provided for investigating the molecular regulation mechanism of heavy metal Pb accumulation and tolerance in root vegetable crops. PMID:23840502

Comparative genomics analysis of field isolates of Aspergillus flavus and A. parasiticus to explain phenotypic variation in oxidative stress tolerance and host preference

USDA-ARS?s Scientific Manuscript database

Aflatoxin contamination of peanut and other crops is a major concern for producers globally, and has been shown to be exacerbated by drought stress. Previous transcriptomic and proteomic examination of the responses of isolates of Aspergillus flavus to drought-related oxidative stress in vitro have ...

Comparative transcriptome analysis of Sogatella furcifera (Horváth) exposed to different insecticides.

PubMed

Zhou, Cao; Yang, Hong; Wang, Zhao; Long, Gui-Yun; Jin, Dao-Chao

2018-06-08

White-backed planthopper, Sogatella furcifera (Horváth) (Hemiptera: Delphacidae), one of the main agricultural insect pests in China, is resistant to a wide variety of insecticides. We used transcriptome analysis to compare the expression patterns of resistance- and stress-response genes in S. furcifera subjected to imidacloprid, deltamethrin, and triazophos stress, to determine the molecular mechanisms of resistance to these insecticides. A comparative analysis of gene expression under imidacloprid, deltamethrin, and triazophos stress revealed 1,123, 841, and 316 upregulated unigenes, respectively, compared to the control. These upregulated genes included seven P450s (two CYP2 clade, three CYP3 clade, and two CYP4 clade), one GST, one ABC transporter (ABCF), and seven Hsps (one 90 and six Hsp70s) under imidacloprid stress; one P450 (CYP3 clade), two ABC transporters (one ABCF and one ABCD), and one Hsp (Hsp90) under deltamethrin stress; one P450 (CYP3 clade) and one ABC transporter (ABCF) under triazophos stress. In addition, 80 genes were commonly upregulated in response to the three insecticide treatments, including laminin, larval cuticle protein, and fasciclin, which are associated with epidermal formation. These results provide a valuable resource for the molecular characterisation of insecticide action in S. furcifera, especially the molecular characteristics of insecticide cross resistance.

Transcriptome Analysis of Two Species of Jute in Response to Polyethylene Glycol (PEG)- induced Drought Stress.

PubMed

Yang, Zemao; Dai, Zhigang; Lu, Ruike; Wu, Bibo; Tang, Qing; Xu, Ying; Cheng, Chaohua; Su, Jianguang

2017-11-29

Drought stress results in significant crop yield losses. Comparative transcriptome analysis between tolerant and sensitive species can provide insights into drought tolerance mechanisms in jute. We present a comprehensive study on drought tolerance in two jute species-a drought tolerant species (Corchorus olitorius L., GF) and a drought sensitive species (Corchorus capsularis L., YY). In total, 45,831 non-redundant unigenes with average sequence length of 1421 bp were identified. Higher numbers of differentially expressed genes (DEGs) were discovered in YY (794) than in GF (39), implying that YY was relatively more vulnerable or hyper-responsive to drought stress at the molecular level; the two main pathways, phenylpropanoid biosynthesis and peroxisome pathway, significantly involved in scavenging of reactive oxygen species (ROS) and 14 unigenes in the two pathways presented a significant differential expression in response to increase of superoxide. Our classification analysis showed that 1769 transcription factors can be grouped into 81 families and 948 protein kinases (PKs) into 122 families. In YY, we identified 34 TF DEGs from and 23 PK DEGs, including 19 receptor-like kinases (RLKs). Most of these RLKs were downregulated during drought stress, implying their role as negative regulators of the drought tolerance mechanism in jute.

Transcriptome analysis and identification of significantly differentially expressed genes in Holstein calves subjected to severe thermal stress

NASA Astrophysics Data System (ADS)

Srikanth, Krishnamoorthy; Lee, Eunjin; Kwan, Anam; Lim, Youngjo; Lee, Junyep; Jang, Gulwon; Chung, Hoyoung

2017-11-01

RNA-Seq analysis was used to characterize transcriptome response of Holstein calves to thermal stress. A total of eight animals aged between 2 and 3 months were randomly selected and subjected to thermal stress corresponding to a temperature humidity index of 95 in an environmentally controlled house for 12 h consecutively for 3 days. A set of 15,787 unigenes were found to be expressed and after a threshold of threefold change, and a Q value <0.05; 502, 394, and 376 genes were found to be differentially expressed on days 1, 2, and 3 out of which 343, 261 and 256 genes were upregulated and 159, 133, and 120 genes were downregulated. Only 356 genes out of these were expressed on all 3 days, and only they were considered as significantly differentially expressed. KEGG pathway analysis revealed that ten pathways were significantly enriched; the top two among them were protein processing in endoplasmic reticulum and MAPK signaling pathways. These results suggest that thermal stress triggered a complex response in Holstein calves and the animals adjusted their physiological and metabolic processes to survive. Many of the genes identified in this study have not been previously reported to be involved in thermal stress response. The results of this study extend our understanding of the animal's response to thermal stress and some of the identified genes may prove useful in the efforts to breed Holstein cattle with superior thermotolerance, which might help in minimizing production loss due to thermal stress.

Cereal Crop Proteomics: Systemic Analysis of Crop Drought Stress Responses Towards Marker-Assisted Selection Breeding

PubMed Central

Ghatak, Arindam; Chaturvedi, Palak; Weckwerth, Wolfram

2017-01-01

Sustainable crop production is the major challenge in the current global climate change scenario. Drought stress is one of the most critical abiotic factors which negatively impact crop productivity. In recent years, knowledge about molecular regulation has been generated to understand drought stress responses. For example, information obtained by transcriptome analysis has enhanced our knowledge and facilitated the identification of candidate genes which can be utilized for plant breeding. On the other hand, it becomes more and more evident that the translational and post-translational machinery plays a major role in stress adaptation, especially for immediate molecular processes during stress adaptation. Therefore, it is essential to measure protein levels and post-translational protein modifications to reveal information about stress inducible signal perception and transduction, translational activity and induced protein levels. This information cannot be revealed by genomic or transcriptomic analysis. Eventually, these processes will provide more direct insight into stress perception then genetic markers and might build a complementary basis for future marker-assisted selection of drought resistance. In this review, we survey the role of proteomic studies to illustrate their applications in crop stress adaptation analysis with respect to productivity. Cereal crops such as wheat, rice, maize, barley, sorghum and pearl millet are discussed in detail. We provide a comprehensive and comparative overview of all detected protein changes involved in drought stress in these crops and have summarized existing knowledge into a proposed scheme of drought response. Based on a recent proteome study of pearl millet under drought stress we compare our findings with wheat proteomes and another recent study which defined genetic marker in pearl millet. PMID:28626463

Genome-wide transcriptome analysis of soybean primary root under varying water-deficit conditions.

PubMed

Song, Li; Prince, Silvas; Valliyodan, Babu; Joshi, Trupti; Maldonado dos Santos, Joao V; Wang, Jiaojiao; Lin, Li; Wan, Jinrong; Wang, Yongqin; Xu, Dong; Nguyen, Henry T

2016-01-15

Soybean is a major crop that provides an important source of protein and oil to humans and animals, but its production can be dramatically decreased by the occurrence of drought stress. Soybeans can survive drought stress if there is a robust and deep root system at the early vegetative growth stage. However, little is known about the genome-wide molecular mechanisms contributing to soybean root system architecture. This study was performed to gain knowledge on transcriptome changes and related molecular mechanisms contributing to soybean root development under water limited conditions. The soybean Williams 82 genotype was subjected to very mild stress (VMS), mild stress (MS) and severe stress (SS) conditions, as well as recovery from the severe stress after re-watering (SR). In total, 6,609 genes in the roots showed differential expression patterns in response to different water-deficit stress levels. Genes involved in hormone (Auxin/Ethylene), carbohydrate, and cell wall-related metabolism (XTH/lipid/flavonoids/lignin) pathways were differentially regulated in the soybean root system. Several transcription factors (TFs) regulating root growth and responses under varying water-deficit conditions were identified and the expression patterns of six TFs were found to be common across the stress levels. Further analysis on the whole plant level led to the finding of tissue-specific or water-deficit levels specific regulation of transcription factors. Analysis of the over-represented motif of different gene groups revealed several new cis-elements associated with different levels of water deficit. The expression patterns of 18 genes were confirmed byquantitative reverse transcription polymerase chain reaction method and demonstrated the accuracy and effectiveness of RNA-Seq. The primary root specific transcriptome in soybean can enable a better understanding of the root response to water deficit conditions. The genes detected in root tissues that were associated with key hormones, carbohydrates, and cell wall-related metabolism could play a vital role in achieving drought tolerance and could be promising candidates for future functional characterization. TFs involved in the soybean root and at the whole plant level could be used for future network analysis between TFs and cis-elements. All of these findings will be helpful in elucidating the molecular mechanisms associated with water stress responses in soybean roots.

Connecting genes, coexpression modules, and molecular signatures to environmental stress phenotypes in plants

PubMed Central

Weston, David J; Gunter, Lee E; Rogers, Alistair; Wullschleger, Stan D

2008-01-01

Background One of the eminent opportunities afforded by modern genomic technologies is the potential to provide a mechanistic understanding of the processes by which genetic change translates to phenotypic variation and the resultant appearance of distinct physiological traits. Indeed much progress has been made in this area, particularly in biomedicine where functional genomic information can be used to determine the physiological state (e.g., diagnosis) and predict phenotypic outcome (e.g., patient survival). Ecology currently lacks an analogous approach where genomic information can be used to diagnose the presence of a given physiological state (e.g., stress response) and then predict likely phenotypic outcomes (e.g., stress duration and tolerance, fitness). Results Here, we demonstrate that a compendium of genomic signatures can be used to classify the plant abiotic stress phenotype in Arabidopsis according to the architecture of the transcriptome, and then be linked with gene coexpression network analysis to determine the underlying genes governing the phenotypic response. Using this approach, we confirm the existence of known stress responsive pathways and marker genes, report a common abiotic stress responsive transcriptome and relate phenotypic classification to stress duration. Conclusion Linking genomic signatures to gene coexpression analysis provides a unique method of relating an observed plant phenotype to changes in gene expression that underlie that phenotype. Such information is critical to current and future investigations in plant biology and, in particular, to evolutionary ecology, where a mechanistic understanding of adaptive physiological responses to abiotic stress can provide researchers with a tool of great predictive value in understanding species and population level adaptation to climate change. PMID:18248680

Analysis of petunia hybrida in response to salt stress using high throughput RNA sequencing

USDA-ARS?s Scientific Manuscript database

Salt and drought are among the greatest challenges to crop and native plants in meeting their yield and reproductive potentials. DNA sequencing-enabled transcriptome profiling provides a means of assessing what genes are responding to salt or drought stress so as to better understand the molecular ...

Physiological and transcriptomic responses in the seed coat of field-grown soybean (Glycine max L. Merr.) to abiotic stress.

PubMed

Leisner, Courtney P; Yendrek, Craig R; Ainsworth, Elizabeth A

2017-12-12

Understanding how intensification of abiotic stress due to global climate change affects crop yields is important for continued agricultural productivity. Coupling genomic technologies with physiological crop responses in a dynamic field environment is an effective approach to dissect the mechanisms underpinning crop responses to abiotic stress. Soybean (Glycine max L. Merr. cv. Pioneer 93B15) was grown in natural production environments with projected changes to environmental conditions predicted for the end of the century, including decreased precipitation, increased tropospheric ozone concentrations ([O 3 ]), or increased temperature. All three environmental stresses significantly decreased leaf-level photosynthesis and stomatal conductance, leading to significant losses in seed yield. This was driven by a significant decrease in the number of pods per node for all abiotic stress treatments. To understand the underlying transcriptomic response involved in the yield response to environmental stress, RNA-Sequencing analysis was performed on the soybean seed coat, a tissue that plays an essential role in regulating carbon and nitrogen transport to developing seeds. Gene expression analysis revealed 49, 148 and 1,576 differentially expressed genes in the soybean seed coat in response to drought, elevated [O 3 ] and elevated temperature, respectively. Elevated [O 3 ] and drought did not elicit substantive transcriptional changes in the soybean seed coat. However, this may be due to the timing of sampling and does not preclude impacts of those stresses on different tissues or different stages in seed coat development. Expression of genes involved in DNA replication and metabolic processes were enriched in the seed coat under high temperate stress, suggesting that the timing of events that are important for cell division and proper seed development were altered in a stressful growth environment.

Cross-omics comparison of stress responses in mesothelial cells exposed to heat- versus filter-sterilized peritoneal dialysis fluids.

PubMed

Kratochwill, Klaus; Bender, Thorsten O; Lichtenauer, Anton M; Herzog, Rebecca; Tarantino, Silvia; Bialas, Katarzyna; Jörres, Achim; Aufricht, Christoph

2015-01-01

Recent research suggests that cytoprotective responses, such as expression of heat-shock proteins, might be inadequately induced in mesothelial cells by heat-sterilized peritoneal dialysis (PD) fluids. This study compares transcriptome data and multiple protein expression profiles for providing new insight into regulatory mechanisms. Two-dimensional difference gel electrophoresis (2D-DIGE) based proteomics and topic defined gene expression microarray-based transcriptomics techniques were used to evaluate stress responses in human omental peritoneal mesothelial cells in response to heat- or filter-sterilized PD fluids. Data from selected heat-shock proteins were validated by 2D western-blot analysis. Comparison of proteomics and transcriptomics data discriminated differentially regulated protein abundance into groups depending on correlating or noncorrelating transcripts. Inadequate abundance of several heat-shock proteins following exposure to heat-sterilized PD fluids is not reflected on the mRNA level indicating interference beyond transcriptional regulation. For the first time, this study describes evidence for posttranscriptional inadequacy of heat-shock protein expression by heat-sterilized PD fluids as a novel cytotoxic property. Cross-omics technologies introduce a novel way of understanding PDF bioincompatibility and searching for new interventions to reestablish adequate cytoprotective responses.

Concurrent Drought Stress and Vascular Pathogen Infection Induce Common and Distinct Transcriptomic Responses in Chickpea

PubMed Central

Sinha, Ranjita; Gupta, Aarti; Senthil-Kumar, Muthappa

2017-01-01

Chickpea (Cicer arietinum); the second largest legume grown worldwide is prone to drought and various pathogen infections. These drought and pathogen stresses often occur concurrently in the field conditions. However, the molecular events in response to that are largely unknown. The present study examines the transcriptome dynamics in chickpea plants exposed to a combination of water-deficit stress and Ralstonia solanacearum infection. R. solanacearum is a potential wilt disease causing pathogen in chickpea. Drought stressed chickpea plants were infected with this pathogen and the plants were allowed to experience progressive drought with 2 and 4 days of R. solanacearum infection called short duration stress (SD stresses) and long duration stress (LD stresses), respectively. Our study showed that R. solanacearum multiplication decreased under SD-combined stress compared to SD-pathogen but there was no significant change in LD-combined stress compared to LD-pathogen. The microarray analysis during these conditions showed that 821 and 1039 differentially expressed genes (DEGs) were unique to SD- and LD-combined stresses, respectively, when compared with individual stress conditions. Three and fifteen genes were common among all the SD-stress treatments and LD-stress treatments, respectively. Genes involved in secondary cell wall biosynthesis, alkaloid biosynthesis, defense related proteins, and osmo-protectants were up-regulated during combined stress. The expression of genes involved in lignin and cellulose biosynthesis were specifically up-regulated in SD-combined, LD-combined, and LD-pathogen stress. A close transcriptomic association of LD-pathogen stress with SD-combined stress was observed in this study which indicates that R. solanacearum infection also exerts drought stress along with pathogen stress thus mimics combined stress effect. Furthermore the expression profiling of candidate genes using real-time quantitative PCR validated the microarray data. The study showed that down-regulation of defense-related genes during LD-combined stress resulted in an increased bacterial multiplication as compared to SD-combined stress. Overall, our study highlights a sub-set of DEGs uniquely expressed in response to combined stress, which serve as potential candidates for further functional characterization to delineate the molecular response of the plant to concurrent drought-pathogen stress. PMID:28382041

Detecting early signs of heat and drought stress in Phoenix dactylifera (date palm)

PubMed Central

Safronov, Omid; Kreuzwieser, Jürgen; Haberer, Georg; Alyousif, Mohamed S.; Schulze, Waltraud; Al-Harbi, Naif; Arab, Leila; Ache, Peter; Stempfl, Thomas; Kruse, Joerg; Mayer, Klaus X.; Hedrich, Rainer; Rennenberg, Heinz

2017-01-01

Plants adapt to the environment by either long-term genome evolution or by acclimatization processes where the cellular processes and metabolism of the plant are adjusted within the existing potential in the genome. Here we studied the adaptation strategies in date palm, Phoenix dactylifera, under mild heat, drought and combined heat and drought by transcriptomic and metabolomic profiling. In transcriptomics data, combined heat and drought resembled heat response, whereas in metabolomics data it was more similar to drought. In both conditions, soluble carbohydrates, such as fucose, and glucose derivatives, were increased, suggesting a switch to carbohydrate metabolism and cell wall biogenesis. This result is consistent with the evidence from transcriptomics and cis-motif analysis. In addition, transcriptomics data showed transcriptional activation of genes related to reactive oxygen species in all three conditions (drought, heat, and combined heat and drought), suggesting increased activity of enzymatic antioxidant systems in cytosol, chloroplast and peroxisome. Finally, the genes that were differentially expressed in heat and combined heat and drought stresses were significantly enriched for circadian and diurnal rhythm motifs, suggesting new stress avoidance strategies. PMID:28570677

Dehydrin gene expression provides an indicator of low temperature and drought stress: transcriptome-based analysis of barley (Hordeum vulgare L.).

PubMed

Tommasini, Livia; Svensson, Jan T; Rodriguez, Edmundo M; Wahid, Abdul; Malatrasi, Marina; Kato, Kenji; Wanamaker, Steve; Resnik, Josh; Close, Timothy J

2008-11-01

Low temperature and drought have major influences on plant growth and productivity. To identify barley genes involved in responses to these stresses and to specifically test the hypothesis that the dehydrin (Dhn) multigene family can serve as an indicator of the entire transcriptome response, we investigated the response of barley cv. Morex to: (1) gradual drought over 21 days and (2) low temperature including chilling, freeze-thaw cycles, and deacclimation over 33 days. We found 4,153 genes that responded to at least one component of these two stress regimes, about one fourth of all genes called "present" under any condition. About 44% (1,822 of 4,153) responded specifically to drought, whereas only 3.8% (158 of 4,153) were chilling specific and 2.8% (119 of 4,153) freeze-thaw specific, with 34.1% responsive to freeze-thaw and drought. The intersection between chilling and drought (31.9%) was somewhat smaller than the intersection between freeze-thaw and drought, implying an element of osmotic stress response to freeze-thaw. About 82.4% of the responsive genes were similar to Arabidopsis genes. The expression of 13 barley Dhn genes mirrored the global clustering of all transcripts, with specific combinations of Dhn genes providing an excellent indicator of each stress response. Data from these studies provide a robust reference data set for abiotic stress.

The salt-responsive transcriptome of chickpea roots and nodules via deepSuperSAGE

PubMed Central

2011-01-01

Background The combination of high-throughput transcript profiling and next-generation sequencing technologies is a prerequisite for genome-wide comprehensive transcriptome analysis. Our recent innovation of deepSuperSAGE is based on an advanced SuperSAGE protocol and its combination with massively parallel pyrosequencing on Roche's 454 sequencing platform. As a demonstration of the power of this combination, we have chosen the salt stress transcriptomes of roots and nodules of the third most important legume crop chickpea (Cicer arietinum L.). While our report is more technology-oriented, it nevertheless addresses a major world-wide problem for crops generally: high salinity. Together with low temperatures and water stress, high salinity is responsible for crop losses of millions of tons of various legume (and other) crops. Continuously deteriorating environmental conditions will combine with salinity stress to further compromise crop yields. As a good example for such stress-exposed crop plants, we started to characterize salt stress responses of chickpeas on the transcriptome level. Results We used deepSuperSAGE to detect early global transcriptome changes in salt-stressed chickpea. The salt stress responses of 86,919 transcripts representing 17,918 unique 26 bp deepSuperSAGE tags (UniTags) from roots of the salt-tolerant variety INRAT-93 two hours after treatment with 25 mM NaCl were characterized. Additionally, the expression of 57,281 transcripts representing 13,115 UniTags was monitored in nodules of the same plants. From a total of 144,200 analyzed 26 bp tags in roots and nodules together, 21,401 unique transcripts were identified. Of these, only 363 and 106 specific transcripts, respectively, were commonly up- or down-regulated (>3.0-fold) under salt stress in both organs, witnessing a differential organ-specific response to stress. Profiting from recent pioneer works on massive cDNA sequencing in chickpea, more than 9,400 UniTags were able to be linked to UniProt entries. Additionally, gene ontology (GO) categories over-representation analysis enabled to filter out enriched biological processes among the differentially expressed UniTags. Subsequently, the gathered information was further cross-checked with stress-related pathways. From several filtered pathways, here we focus exemplarily on transcripts associated with the generation and scavenging of reactive oxygen species (ROS), as well as on transcripts involved in Na+ homeostasis. Although both processes are already very well characterized in other plants, the information generated in the present work is of high value. Information on expression profiles and sequence similarity for several hundreds of transcripts of potential interest is now available. Conclusions This report demonstrates, that the combination of the high-throughput transcriptome profiling technology SuperSAGE with one of the next-generation sequencing platforms allows deep insights into the first molecular reactions of a plant exposed to salinity. Cross validation with recent reports enriched the information about the salt stress dynamics of more than 9,000 chickpea ESTs, and enlarged their pool of alternative transcripts isoforms. As an example for the high resolution of the employed technology that we coin deepSuperSAGE, we demonstrate that ROS-scavenging and -generating pathways undergo strong global transcriptome changes in chickpea roots and nodules already 2 hours after onset of moderate salt stress (25 mM NaCl). Additionally, a set of more than 15 candidate transcripts are proposed to be potential components of the salt overly sensitive (SOS) pathway in chickpea. Newly identified transcript isoforms are potential targets for breeding novel cultivars with high salinity tolerance. We demonstrate that these targets can be integrated into breeding schemes by micro-arrays and RT-PCR assays downstream of the generation of 26 bp tags by SuperSAGE. PMID:21320317

The salt-responsive transcriptome of chickpea roots and nodules via deepSuperSAGE.

PubMed

Molina, Carlos; Zaman-Allah, Mainassara; Khan, Faheema; Fatnassi, Nadia; Horres, Ralf; Rotter, Björn; Steinhauer, Diana; Amenc, Laurie; Drevon, Jean-Jacques; Winter, Peter; Kahl, Günter

2011-02-14

The combination of high-throughput transcript profiling and next-generation sequencing technologies is a prerequisite for genome-wide comprehensive transcriptome analysis. Our recent innovation of deepSuperSAGE is based on an advanced SuperSAGE protocol and its combination with massively parallel pyrosequencing on Roche's 454 sequencing platform. As a demonstration of the power of this combination, we have chosen the salt stress transcriptomes of roots and nodules of the third most important legume crop chickpea (Cicer arietinum L.). While our report is more technology-oriented, it nevertheless addresses a major world-wide problem for crops generally: high salinity. Together with low temperatures and water stress, high salinity is responsible for crop losses of millions of tons of various legume (and other) crops. Continuously deteriorating environmental conditions will combine with salinity stress to further compromise crop yields. As a good example for such stress-exposed crop plants, we started to characterize salt stress responses of chickpeas on the transcriptome level. We used deepSuperSAGE to detect early global transcriptome changes in salt-stressed chickpea. The salt stress responses of 86,919 transcripts representing 17,918 unique 26 bp deepSuperSAGE tags (UniTags) from roots of the salt-tolerant variety INRAT-93 two hours after treatment with 25 mM NaCl were characterized. Additionally, the expression of 57,281 transcripts representing 13,115 UniTags was monitored in nodules of the same plants. From a total of 144,200 analyzed 26 bp tags in roots and nodules together, 21,401 unique transcripts were identified. Of these, only 363 and 106 specific transcripts, respectively, were commonly up- or down-regulated (>3.0-fold) under salt stress in both organs, witnessing a differential organ-specific response to stress.Profiting from recent pioneer works on massive cDNA sequencing in chickpea, more than 9,400 UniTags were able to be linked to UniProt entries. Additionally, gene ontology (GO) categories over-representation analysis enabled to filter out enriched biological processes among the differentially expressed UniTags. Subsequently, the gathered information was further cross-checked with stress-related pathways. From several filtered pathways, here we focus exemplarily on transcripts associated with the generation and scavenging of reactive oxygen species (ROS), as well as on transcripts involved in Na+ homeostasis. Although both processes are already very well characterized in other plants, the information generated in the present work is of high value. Information on expression profiles and sequence similarity for several hundreds of transcripts of potential interest is now available. This report demonstrates, that the combination of the high-throughput transcriptome profiling technology SuperSAGE with one of the next-generation sequencing platforms allows deep insights into the first molecular reactions of a plant exposed to salinity. Cross validation with recent reports enriched the information about the salt stress dynamics of more than 9,000 chickpea ESTs, and enlarged their pool of alternative transcripts isoforms. As an example for the high resolution of the employed technology that we coin deepSuperSAGE, we demonstrate that ROS-scavenging and -generating pathways undergo strong global transcriptome changes in chickpea roots and nodules already 2 hours after onset of moderate salt stress (25 mM NaCl). Additionally, a set of more than 15 candidate transcripts are proposed to be potential components of the salt overly sensitive (SOS) pathway in chickpea. Newly identified transcript isoforms are potential targets for breeding novel cultivars with high salinity tolerance. We demonstrate that these targets can be integrated into breeding schemes by micro-arrays and RT-PCR assays downstream of the generation of 26 bp tags by SuperSAGE.

The Late Embryogenesis Abundant Protein Family in Cassava (Manihot esculenta Crantz): Genome-Wide Characterization and Expression during Abiotic Stress.

PubMed

Wu, Chunlai; Hu, Wei; Yan, Yan; Tie, Weiwei; Ding, Zehong; Guo, Jianchun; He, Guangyuan

2018-05-17

Late embryogenesis abundant (LEA) proteins, as a highly diverse group of polypeptides, play an important role in plant adaptation to abiotic stress; however, LEAs from cassava have not been studied in cassava. In this study, 26 LEA members were genome-wide identified from cassava, which were clustered into seven subfamily according to evolutionary relationship, protein motif, and gene structure analyses. Chromosomal location and duplication event analyses suggested that 26 MeLEAs distributed in 10 chromosomes and 11 MeLEA paralogues were subjected to purifying selection. Transcriptomic analysis showed the expression profiles of MeLEAs in different tissues of stem, leaves, and storage roots of three accessions. Comparative transcriptomic analysis revealed that the function of MeLEAs in response to drought may be differentiated in different accessions. Compared with the wild subspecies W14, more MeLEA genes were activated in cultivated varieties Arg7 and SC124 after drought treatment. Several MeLEA genes showed induction under various stresses and related signaling treatments. Taken together, this study demonstrates the transcriptional control of MeLEAs in tissue development and the responses to abiotic stress in cassava and identifies candidate genes for improving crop resistance to abiotic stress.

Transcriptome Profiling of the Pineapple under Low Temperature to Facilitate Its Breeding for Cold Tolerance

PubMed Central

Chen, Chengjie; Zhang, Yafeng; Xu, Zhiqiang; Luan, Aiping; Mao, Qi; Feng, Junting; Xie, Tao; Gong, Xue; Wang, Xiaoshuang; Chen, Hao; He, Yehua

2016-01-01

The pineapple (Ananas comosus) is cold sensitive. Most cultivars are injured during winter periods, especially in sub-tropical regions. There is a lack of molecular information on the pineapple’s response to cold stress. In this study, high-throughput transcriptome sequencing and gene expression analysis were performed on plantlets of a cold-tolerant genotype of the pineapple cultivar ‘Shenwan’ before and after cold treatment. A total of 1,186 candidate cold responsive genes were identified, and their credibility was confirmed by RT-qPCR. Gene set functional enrichment analysis indicated that genes related to cell wall properties, stomatal closure and ABA and ROS signal transduction play important roles in pineapple cold tolerance. In addition, a protein association network of CORs (cold responsive genes) was predicted, which could serve as an entry point to dissect the complex cold response network. Our study found a series of candidate genes and their association network, which will be helpful to cold stress response studies and pineapple breeding for cold tolerance. PMID:27656892

Network analysis of oyster transcriptome revealed a cascade of cellular responses during recovery after heat shock.

PubMed

Zhang, Lingling; Hou, Rui; Su, Hailin; Hu, Xiaoli; Wang, Shi; Bao, Zhenmin

2012-01-01

Oysters, as a major group of marine bivalves, can tolerate a wide range of natural and anthropogenic stressors including heat stress. Recent studies have shown that oysters pretreated with heat shock can result in induced heat tolerance. A systematic study of cellular recovery from heat shock may provide insights into the mechanism of acquired thermal tolerance. In this study, we performed the first network analysis of oyster transcriptome by reanalyzing microarray data from a previous study. Network analysis revealed a cascade of cellular responses during oyster recovery after heat shock and identified responsive gene modules and key genes. Our study demonstrates the power of network analysis in a non-model organism with poor gene annotations, which can lead to new discoveries that go beyond the focus on individual genes.

Genomics of Adaptation to Multiple Concurrent Stresses: Insights from Comparative Transcriptomics of a Cichlid Fish from One of Earth's Most Extreme Environments, the Hypersaline Soda Lake Magadi in Kenya, East Africa.

PubMed

Kavembe, Geraldine D; Franchini, Paolo; Irisarri, Iker; Machado-Schiaffino, Gonzalo; Meyer, Axel

2015-10-01

The Magadi tilapia (Alcolapia grahami) is a cichlid fish that inhabits one of the Earth's most extreme aquatic environments, with high pH (~10), salinity (~60% of seawater), high temperatures (~40 °C), and fluctuating oxygen regimes. The Magadi tilapia evolved several unique behavioral, physiological, and anatomical adaptations, some of which are constituent and thus retained in freshwater conditions. We conducted a transcriptomic analysis on A. grahami to study the evolutionary basis of tolerance to multiple stressors. To identify the adaptive regulatory changes associated with stress responses, we massively sequenced gill transcriptomes (RNAseq) from wild and freshwater-acclimated specimens of A. grahami. As a control, corresponding transcriptome data from Oreochromis leucostictus, a closely related freshwater species, were generated. We found expression differences in a large number of genes with known functions related to osmoregulation, energy metabolism, ion transport, and chemical detoxification. Over-representation of metabolism-related gene ontology terms in wild individuals compared to laboratory-acclimated specimens suggested that freshwater conditions greatly decrease the metabolic requirements of this species. Twenty-five genes with diverse physiological functions related to responses to water stress showed signs of divergent natural selection between the Magadi tilapia and its freshwater relative, which shared a most recent common ancestor only about four million years ago. The complete set of genes responsible for urea excretion was identified in the gill transcriptome of A. grahami, making it the only fish species to have a functional ornithine-urea cycle pathway in the gills--a major innovation for increasing nitrogenous waste efficiency.

Day and night heat stress trigger different transcriptomic responses in green and ripening grapevine (vitis vinifera) fruit.

PubMed

Rienth, Markus; Torregrosa, Laurent; Luchaire, Nathalie; Chatbanyong, Ratthaphon; Lecourieux, David; Kelly, Mary T; Romieu, Charles

2014-04-28

Global climate change will noticeably affect plant vegetative and reproductive development. The recent increase in temperatures has already impacted yields and composition of berries in many grapevine-growing regions. Physiological processes underlying temperature response and tolerance of the grapevine fruit have not been extensively investigated. To date, all studies investigating the molecular regulation of fleshly fruit response to abiotic stress were only conducted during the day, overlooking possible critical night-specific variations. The present study explores the night and day transcriptomic response of grapevine fruit to heat stress at several developmental stages. Short heat stresses (2 h) were applied at day and night to vines bearing clusters sequentially ordered according to the developmental stages along their vertical axes. The recently proposed microvine model (DRCF-Dwarf Rapid Cycling and Continuous Flowering) was grown in climatic chambers in order to circumvent common constraints and biases inevitable in field experiments with perennial macrovines. Post-véraison berry heterogeneity within clusters was avoided by constituting homogenous batches following organic acids and sugars measurements of individual berries. A whole genome transcriptomic approach was subsequently conducted using NimbleGen 090818 Vitis 12X (30 K) microarrays. Present work reveals significant differences in heat stress responsive pathways according to day or night treatment, in particular regarding genes associated with acidity and phenylpropanoid metabolism. Precise distinction of ripening stages led to stage-specific detection of malic acid and anthocyanin-related transcripts modulated by heat stress. Important changes in cell wall modification related processes as well as indications for heat-induced delay of ripening and sugar accumulation were observed at véraison, an effect that was reversed at later stages. This first day - night study on heat stress adaption of the grapevine berry shows that the transcriptome of fleshy fruits is differentially affected by abiotic stress at night. The present results emphasize the necessity of including different developmental stages and especially several daytime points in transcriptomic studies.

Global transcriptomic analysis of the response of Corynebacterium glutamicum to ferulic acid.

PubMed

Chen, Can; Pan, Junfeng; Yang, Xiaobing; Xiao, He; Zhang, Yaoling; Si, Meiru; Shen, Xihui; Wang, Yao

2017-03-01

Corynebacterium glutamicum can survive by using ferulic acid as the sole carbon source. In this study, we assessed the response of C. glutamicum to ferulic acid stress by means of a global transcriptional response analysis. The transcriptional data showed that several genes involved in degradation of ferulic acid were affected. Moreover, several genes related to the stress response; protein protection or degradation and DNA repair; replication, transcription and translation; and the cell envelope were differentially expressed. Deletion of the katA or sigE gene in C. glutamicum resulted in a decrease in cell viability under ferulic acid stress. These insights will facilitate further engineering of model industrial strains, with enhanced tolerance to ferulic acid to enable easy production of biofuels from lignocellulose.

A Systems Biology Study in Tomato Fruit Reveals Correlations between the Ascorbate Pool and Genes Involved in Ribosome Biogenesis, Translation, and the Heat-Shock Response

PubMed Central

Stevens, Rebecca G.; Baldet, Pierre; Bouchet, Jean-Paul; Causse, Mathilde; Deborde, Catherine; Deschodt, Claire; Faurobert, Mireille; Garchery, Cécile; Garcia, Virginie; Gautier, Hélène; Gouble, Barbara; Maucourt, Mickaël; Moing, Annick; Page, David; Petit, Johann; Poëssel, Jean-Luc; Truffault, Vincent; Rothan, Christophe

2018-01-01

Changing the balance between ascorbate, monodehydroascorbate, and dehydroascorbate in plant cells by manipulating the activity of enzymes involved in ascorbate synthesis or recycling of oxidized and reduced forms leads to multiple phenotypes. A systems biology approach including network analysis of the transcriptome, proteome and metabolites of RNAi lines for ascorbate oxidase, monodehydroascorbate reductase and galactonolactone dehydrogenase has been carried out in orange fruit pericarp of tomato (Solanum lycopersicum). The transcriptome of the RNAi ascorbate oxidase lines is inversed compared to the monodehydroascorbate reductase and galactonolactone dehydrogenase lines. Differentially expressed genes are involved in ribosome biogenesis and translation. This transcriptome inversion is also seen in response to different stresses in Arabidopsis. The transcriptome response is not well correlated with the proteome which, with the metabolites, are correlated to the activity of the ascorbate redox enzymes—ascorbate oxidase and monodehydroascorbate reductase. Differentially accumulated proteins include metacaspase, protein disulphide isomerase, chaperone DnaK and carbonic anhydrase and the metabolites chlorogenic acid, dehydroascorbate and alanine. The hub genes identified from the network analysis are involved in signaling, the heat-shock response and ribosome biogenesis. The results from this study therefore reveal one or several putative signals from the ascorbate pool which modify the transcriptional response and elements downstream. PMID:29491875

Global transcriptomic responses of Escherichia coli K-12 to volatile organic compounds.

PubMed

Yung, Pui Yi; Grasso, Letizia Lo; Mohidin, Abeed Fatima; Acerbi, Enzo; Hinks, Jamie; Seviour, Thomas; Marsili, Enrico; Lauro, Federico M

2016-01-28

Volatile organic compounds (VOCs) are commonly used as solvents in various industrial settings. Many of them present a challenge to receiving environments, due to their toxicity and low bioavailability for degradation. Microorganisms are capable of sensing and responding to their surroundings and this makes them ideal detectors for toxic compounds. This study investigates the global transcriptomic responses of Escherichia coli K-12 to selected VOCs at sub-toxic levels. Cells grown in the presence of VOCs were harvested during exponential growth, followed by whole transcriptome shotgun sequencing (RNAseq). The analysis of the data revealed both shared and unique genetic responses compared to cells without exposure to VOCs. Results suggest that various functional gene categories, for example, those relating to Fe/S cluster biogenesis, oxidative stress responses and transport proteins, are responsive to selected VOCs in E. coli. The differential expression (DE) of genes was validated using GFP-promoter fusion assays. A variety of genes were differentially expressed even at non-inhibitory concentrations and when the cells are at their balanced-growth. Some of these genes belong to generic stress response and others could be specific to VOCs. Such candidate genes and their regulatory elements could be used as the basis for designing biosensors for selected VOCs.

Global transcriptomic responses of Escherichia coli K-12 to volatile organic compounds

PubMed Central

Yung, Pui Yi; Grasso, Letizia Lo; Mohidin, Abeed Fatima; Acerbi, Enzo; Hinks, Jamie; Seviour, Thomas; Marsili, Enrico; Lauro, Federico M.

2016-01-01

Volatile organic compounds (VOCs) are commonly used as solvents in various industrial settings. Many of them present a challenge to receiving environments, due to their toxicity and low bioavailability for degradation. Microorganisms are capable of sensing and responding to their surroundings and this makes them ideal detectors for toxic compounds. This study investigates the global transcriptomic responses of Escherichia coli K-12 to selected VOCs at sub-toxic levels. Cells grown in the presence of VOCs were harvested during exponential growth, followed by whole transcriptome shotgun sequencing (RNAseq). The analysis of the data revealed both shared and unique genetic responses compared to cells without exposure to VOCs. Results suggest that various functional gene categories, for example, those relating to Fe/S cluster biogenesis, oxidative stress responses and transport proteins, are responsive to selected VOCs in E. coli. The differential expression (DE) of genes was validated using GFP-promoter fusion assays. A variety of genes were differentially expressed even at non-inhibitory concentrations and when the cells are at their balanced-growth. Some of these genes belong to generic stress response and others could be specific to VOCs. Such candidate genes and their regulatory elements could be used as the basis for designing biosensors for selected VOCs. PMID:26818886

Temporal network analysis identifies early physiological and transcriptomic indicators of mild drought in Brassica rapa

PubMed Central

Gehan, Malia A; Mockler, Todd C; Weinig, Cynthia; Ewers, Brent E

2017-01-01

The dynamics of local climates make development of agricultural strategies challenging. Yield improvement has progressed slowly, especially in drought-prone regions where annual crop production suffers from episodic aridity. Underlying drought responses are circadian and diel control of gene expression that regulate daily variations in metabolic and physiological pathways. To identify transcriptomic changes that occur in the crop Brassica rapa during initial perception of drought, we applied a co-expression network approach to associate rhythmic gene expression changes with physiological responses. Coupled analysis of transcriptome and physiological parameters over a two-day time course in control and drought-stressed plants provided temporal resolution necessary for correlation of network modules with dynamic changes in stomatal conductance, photosynthetic rate, and photosystem II efficiency. This approach enabled the identification of drought-responsive genes based on their differential rhythmic expression profiles in well-watered versus droughted networks and provided new insights into the dynamic physiological changes that occur during drought. PMID:28826479

A eukaryotic-type signalling system of Pseudomonas aeruginosa contributes to oxidative stress resistance, intracellular survival and virulence

PubMed Central

2011-01-01

Background The genome of Pseudomonas aeruginosa contains at least three genes encoding eukaryotic-type Ser/Thr protein kinases, one of which, ppkA, has been implicated in P. aeruginosa virulence. Together with the adjacent pppA phosphatase gene, they belong to the type VI secretion system (H1-T6SS) locus, which is important for bacterial pathogenesis. To determine the biological function of this protein pair, we prepared a pppA-ppkA double mutant and characterised its phenotype and transcriptomic profiles. Results Phenotypic studies revealed that the mutant grew slower than the wild-type strain in minimal media and exhibited reduced secretion of pyoverdine. In addition, the mutant had altered sensitivity to oxidative and hyperosmotic stress conditions. Consequently, mutant cells had an impaired ability to survive in murine macrophages and an attenuated virulence in the plant model of infection. Whole-genome transcriptome analysis revealed that pppA-ppkA deletion affects the expression of oxidative stress-responsive genes, stationary phase σ-factor RpoS-regulated genes, and quorum-sensing regulons. The transcriptome of the pppA-ppkA mutant was also analysed under conditions of oxidative stress and showed an impaired response to the stress, manifested by a weaker induction of stress adaptation genes as well as the genes of the SOS regulon. In addition, expression of either RpoS-regulated genes or quorum-sensing-dependent genes was also affected. Complementation analysis confirmed that the transcription levels of the differentially expressed genes were specifically restored when the pppA and ppkA genes were expressed ectopically. Conclusions Our results suggest that in addition to its crucial role in controlling the activity of P. aeruginosa H1-T6SS at the post-translational level, the PppA-PpkA pair also affects the transcription of stress-responsive genes. Based on these data, it is likely that the reduced virulence of the mutant strain results from an impaired ability to survive in the host due to the limited response to stress conditions. PMID:21880152

A eukaryotic-type signalling system of Pseudomonas aeruginosa contributes to oxidative stress resistance, intracellular survival and virulence.

PubMed

Goldová, Jana; Ulrych, Aleš; Hercík, Kamil; Branny, Pavel

2011-08-31

The genome of Pseudomonas aeruginosa contains at least three genes encoding eukaryotic-type Ser/Thr protein kinases, one of which, ppkA, has been implicated in P. aeruginosa virulence. Together with the adjacent pppA phosphatase gene, they belong to the type VI secretion system (H1-T6SS) locus, which is important for bacterial pathogenesis. To determine the biological function of this protein pair, we prepared a pppA-ppkA double mutant and characterised its phenotype and transcriptomic profiles. Phenotypic studies revealed that the mutant grew slower than the wild-type strain in minimal media and exhibited reduced secretion of pyoverdine. In addition, the mutant had altered sensitivity to oxidative and hyperosmotic stress conditions. Consequently, mutant cells had an impaired ability to survive in murine macrophages and an attenuated virulence in the plant model of infection. Whole-genome transcriptome analysis revealed that pppA-ppkA deletion affects the expression of oxidative stress-responsive genes, stationary phase σ-factor RpoS-regulated genes, and quorum-sensing regulons. The transcriptome of the pppA-ppkA mutant was also analysed under conditions of oxidative stress and showed an impaired response to the stress, manifested by a weaker induction of stress adaptation genes as well as the genes of the SOS regulon. In addition, expression of either RpoS-regulated genes or quorum-sensing-dependent genes was also affected. Complementation analysis confirmed that the transcription levels of the differentially expressed genes were specifically restored when the pppA and ppkA genes were expressed ectopically. Our results suggest that in addition to its crucial role in controlling the activity of P. aeruginosa H1-T6SS at the post-translational level, the PppA-PpkA pair also affects the transcription of stress-responsive genes. Based on these data, it is likely that the reduced virulence of the mutant strain results from an impaired ability to survive in the host due to the limited response to stress conditions.

Transcriptomic Analysis of the Primary Roots of Alhagi sparsifolia in Response to Water Stress

PubMed Central

Pei, Xinwu; Zhang, Chao; Jia, Shirong; Li, Weimin

2015-01-01

Background Alhagi sparsifolia is a typical desert phreatophyte and has evolved to withstand extreme dry, cold and hot weather. While A. sparsifolia represents an ideal model to study the molecular mechanism of plant adaption to abiotic stress, no research has been done in this aspect to date. Here we took advantage of Illumina platform to survey transcriptome in primary roots of A. sparsifolia under water stress conditions in aim to facilitate the exploration of its genetic basis for drought tolerance. Methodology and Principal Findings We sequenced four primary roots samples individually collected at 0, 6, 24 and 30h from the A. sparsifolia seedlings in the course of 24h of water stress following 6h of rehydration. The resulting 38,763,230, 67,511,150, 49,259,804 and 54,744,906 clean reads were pooled and assembled into 33,255 unigenes with an average length of 1,057 bp. All-unigenes were subjected to functional annotation by searching against the public databases. Based on the established transcriptome database, we further evaluated the gene expression profiles in the four different primary roots samples, and identified numbers of differently expressed genes (DEGs) reflecting the early response to water stress (6h vs. 0h), the late response to water stress (24h vs. 0h) and the response to post water stress rehydration (30h vs. 24h). Moreover, the DEGs specifically regulated at 6, 24 and 30h were captured in order to depict the dynamic changes of gene expression during water stress and subsequent rehydration. Functional categorization of the DEGs indicated the activation of oxidoreductase system, and particularly emphasized the significance of the ‘Glutathione metabolism pathway’ in response to water stress. Conclusions This is the first description of the genetic makeup of A. sparsifolia, thus providing a substantial contribution to the sequence resources for this species. The identified DEGs offer a deep insight into the molecular mechanism of A. sparsifolia in response to water stress, and merit further investigation. PMID:25822368

Differential transcriptome analysis reveals genes related to cold tolerance in seabuckthorn carpenter moth, Eogystia hippophaecolus

PubMed Central

Hu, Ping; Wang, Tao; Tao, Jing; Zong, Shixiang

2017-01-01

Seabuckthorn carpenter moth, Eogystia hippophaecolus (Lepidoptera: Cossidae), is an important pest of sea buckthorn (Hippophae rhamnoides), which is a shrub that has significant ecological and economic value in China. E. hippophaecolus is highly cold tolerant, but limited studies have been conducted to elucidate the molecular mechanisms underlying its cold resistance. Here we sequenced the E. hippophaecolus transcriptome using RNA-Seq technology and performed de novo assembly from the short paired-end reads. We investigated the larval response to cold stress by comparing gene expression profiles between treatments. We obtained 118,034 unigenes, of which 22,161 were annotated with gene descriptions, conserved domains, gene ontology terms, and metabolic pathways. These resulted in 57 GO terms and 193 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. By comparing transcriptome profiles for differential gene expression, we identified many differentially expressed proteins and genes, including heat shock proteins and cuticular proteins which have previously been reported to be involved in cold resistance of insects. This study provides a global transcriptome analysis and an assessment of differential gene expression in E. hippophaecolus under cold stress. We found seven differential expressed genes in common between developmental stages, which were verified with qPCR. Our findings facilitate future genomic studies aimed at improving our understanding of the molecular mechanisms underlying the response of insects to low temperatures. PMID:29131867

Differential transcriptome analysis reveals genes related to cold tolerance in seabuckthorn carpenter moth, Eogystia hippophaecolus.

PubMed

Cui, Mingming; Hu, Ping; Wang, Tao; Tao, Jing; Zong, Shixiang

2017-01-01

Seabuckthorn carpenter moth, Eogystia hippophaecolus (Lepidoptera: Cossidae), is an important pest of sea buckthorn (Hippophae rhamnoides), which is a shrub that has significant ecological and economic value in China. E. hippophaecolus is highly cold tolerant, but limited studies have been conducted to elucidate the molecular mechanisms underlying its cold resistance. Here we sequenced the E. hippophaecolus transcriptome using RNA-Seq technology and performed de novo assembly from the short paired-end reads. We investigated the larval response to cold stress by comparing gene expression profiles between treatments. We obtained 118,034 unigenes, of which 22,161 were annotated with gene descriptions, conserved domains, gene ontology terms, and metabolic pathways. These resulted in 57 GO terms and 193 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. By comparing transcriptome profiles for differential gene expression, we identified many differentially expressed proteins and genes, including heat shock proteins and cuticular proteins which have previously been reported to be involved in cold resistance of insects. This study provides a global transcriptome analysis and an assessment of differential gene expression in E. hippophaecolus under cold stress. We found seven differential expressed genes in common between developmental stages, which were verified with qPCR. Our findings facilitate future genomic studies aimed at improving our understanding of the molecular mechanisms underlying the response of insects to low temperatures.

The green ash transcriptome and identification of genes responding to abiotic and biotic stresses

Treesearch

Thomas Lane; Teodora Best; Nicole Zembower; Jack Davitt; Nathan Henry; Yi Xu; Jennifer Koch; Haiying Liang; John McGraw; Stephan Schuster; Donghwan Shim; Mark V. Coggeshall; John E. Carlson; Margaret E. Staton

2016-01-01

Background: To develop a set of transcriptome sequences to support research on environmental stress responses in green ash (Fraxinus pennsylvanica), we undertook deep RNA sequencing of green ash tissues under various stress treatments. The treatments, including emerald ash borer (EAB) feeding, heat, drought, cold and ozone, were selected to mimic...

Staying alive in adversity: transcriptome dynamics in the stress-resistant dauer larva.

PubMed

Holt, Suzan J

2006-10-01

In response to food depletion and overcrowding, the soil nematode Caenorhabditis elegans can arrest development and form an alternate third larval stage called the dauer. Though nonfeeding, the dauer larva is long lived and stress resistant. Metabolic and transcription rates are lowered but the transcriptome of the dauer is complex. In this study, distribution analysis of transcript profiles generated by Serial Analysis of Gene Expression (SAGE) in dauer larvae and in mixed developmental stages is presented. An inverse relationship was observed between frequency and abundance/copy number of SAGE tag types (transcripts) in both profiles. In the dauer profile, a relatively greater proportion of highly abundant transcripts was counterbalanced by a smaller fraction of low to moderately abundant transcripts. Comparisons of abundant tag counts between the two profiles revealed relative enrichment in the dauer profile of transcripts with predicted or known involvement in ribosome biogenesis and protein synthesis, membrane transport, and immune responses. Translation-coupled mRNA decay is proposed as part of an immune-like stress response in the dauer larva. An influence of genomic region on transcript level may reflect the coordination of transcription and mRNA turnover.

Genome-Wide Identification and Expression Analysis of the KUP Family under Abiotic Stress in Cassava (Manihot esculenta Crantz).

PubMed

Ou, Wenjun; Mao, Xiang; Huang, Chao; Tie, Weiwei; Yan, Yan; Ding, Zehong; Wu, Chunlai; Xia, Zhiqiang; Wang, Wenquan; Zhou, Shiyi; Li, Kaimian; Hu, Wei

2018-01-01

KT/HAK/KUP (KUP) family is responsible for potassium ion (K + ) transport, which plays a vital role in the response of plants to abiotic stress by maintaining osmotic balance. However, our understanding of the functions of the KUP family in the drought-resistant crop cassava ( Manihot esculenta Crantz) is limited. In the present study, 21 cassava KUP genes ( MeKUPs ) were identified and classified into four clusters based on phylogenetic relationships, conserved motifs, and gene structure analyses. Transcriptome analysis revealed the expression diversity of cassava KUPs in various tissues of three genotypes. Comparative transcriptome analysis showed that the activation of MeKUP genes by drought was more in roots than that in leaves of Arg7 and W14 genotypes, whereas less in roots than that in leaves of SC124 variety. These findings indicate that different cassava genotypes utilize various drought resistance mechanism mediated by KUP genes. Specific KUP genes showed broad upregulation after exposure to salt, osmotic, cold, H 2 O 2 , and abscisic acid (ABA) treatments. Taken together, this study provides insights into the KUP -mediated drought response of cassava at transcription levels and identifies candidate genes that may be utilized in improving crop tolerance to abiotic stress.

Comparative transcriptome analysis reveals different molecular mechanisms of Bacillus coagulans 2-6 response to sodium lactate and calcium lactate during lactic acid production.

PubMed

Qin, Jiayang; Wang, Xiuwen; Wang, Landong; Zhu, Beibei; Zhang, Xiaohua; Yao, Qingshou; Xu, Ping

2015-01-01

Lactate production is enhanced by adding calcium carbonate or sodium hydroxide during fermentation. However, Bacillus coagulans 2-6 can produce more than 180 g/L L-lactic acid when calcium lactate is accumulated, but less than 120 g/L L-lactic acid when sodium lactate is formed. The molecular mechanisms by which B. coagulans responds to calcium lactate and sodium lactate remain unclear. In this study, comparative transcriptomic methods based on high-throughput RNA sequencing were applied to study gene expression changes in B. coagulans 2-6 cultured in non-stress, sodium lactate stress and calcium lactate stress conditions. Gene expression profiling identified 712 and 1213 significantly regulated genes in response to calcium lactate stress and sodium lactate stress, respectively. Gene ontology assignments of the differentially expressed genes were performed. KEGG pathway enrichment analysis revealed that 'ATP-binding cassette transporters' were significantly affected by calcium lactate stress, and 'amino sugar and nucleotide sugar metabolism' was significantly affected by sodium lactate stress. It was also found that lactate fermentation was less affected by calcium lactate stress than by sodium lactate stress. Sodium lactate stress had negative effect on the expression of 'glycolysis/gluconeogenesis' genes but positive effect on the expression of 'citrate cycle (TCA cycle)' genes. However, calcium lactate stress had positive influence on the expression of 'glycolysis/gluconeogenesis' genes and had minor influence on 'citrate cycle (TCA cycle)' genes. Thus, our findings offer new insights into the responses of B. coagulans to different lactate stresses. Notably, our RNA-seq dataset constitute a robust database for investigating the functions of genes induced by lactate stress in the future and identify potential targets for genetic engineering to further improve L-lactic acid production by B. coagulans.

Transcriptome analysis in tardigrade species reveals specific molecular pathways for stress adaptations.

PubMed

Förster, Frank; Beisser, Daniela; Grohme, Markus A; Liang, Chunguang; Mali, Brahim; Siegl, Alexander Matthias; Engelmann, Julia C; Shkumatov, Alexander V; Schokraie, Elham; Müller, Tobias; Schnölzer, Martina; Schill, Ralph O; Frohme, Marcus; Dandekar, Thomas

2012-01-01

Tardigrades have unique stress-adaptations that allow them to survive extremes of cold, heat, radiation and vacuum. To study this, encoded protein clusters and pathways from an ongoing transcriptome study on the tardigrade Milnesium tardigradum were analyzed using bioinformatics tools and compared to expressed sequence tags (ESTs) from Hypsibius dujardini, revealing major pathways involved in resistance against extreme environmental conditions. ESTs are available on the Tardigrade Workbench along with software and databank updates. Our analysis reveals that RNA stability motifs for M. tardigradum are different from typical motifs known from higher animals. M. tardigradum and H. dujardini protein clusters and conserved domains imply metabolic storage pathways for glycogen, glycolipids and specific secondary metabolism as well as stress response pathways (including heat shock proteins, bmh2, and specific repair pathways). Redox-, DNA-, stress- and protein protection pathways complement specific repair capabilities to achieve the strong robustness of M. tardigradum. These pathways are partly conserved in other animals and their manipulation could boost stress adaptation even in human cells. However, the unique combination of resistance and repair pathways make tardigrades and M. tardigradum in particular so highly stress resistant.

Temporal transcriptome profiling reveals expression partitioning of homeologous genes contributing to heat and drought acclimation in wheat (Triticum aestivum L.).

PubMed

Liu, Zhenshan; Xin, Mingming; Qin, Jinxia; Peng, Huiru; Ni, Zhongfu; Yao, Yingyin; Sun, Qixin

2015-06-20

Hexaploid wheat (Triticum aestivum) is a globally important crop. Heat, drought and their combination dramatically reduce wheat yield and quality, but the molecular mechanisms underlying wheat tolerance to extreme environments, especially stress combination, are largely unknown. As an allohexaploid, wheat consists of three closely related subgenomes (A, B, and D), and was reported to show improved tolerance to stress conditions compared to tetraploid. But so far very little is known about how wheat coordinates the expression of homeologous genes to cope with various environmental constraints on the whole-genome level. To explore the transcriptional response of wheat to the individual and combined stress, we performed high-throughput transcriptome sequencing of seedlings under normal condition and subjected to drought stress (DS), heat stress (HS) and their combination (HD) for 1 h and 6 h, and presented global gene expression reprograms in response to these three stresses. Gene Ontology (GO) enrichment analysis of DS, HS and HD responsive genes revealed an overlap and complexity of functional pathways between each other. Moreover, 4,375 wheat transcription factors were identified on a whole-genome scale based on the released scaffold information by IWGSC, and 1,328 were responsive to stress treatments. Then, the regulatory network analysis of HSFs and DREBs implicated they were both involved in the regulation of DS, HS and HD response and indicated a cross-talk between heat and drought stress. Finally, approximately 68.4 % of homeologous genes were found to exhibit expression partitioning in response to DS, HS or HD, which was further confirmed by using quantitative RT-PCR and Nullisomic-Tetrasomic lines. A large proportion of wheat homeologs exhibited expression partitioning under normal and abiotic stresses, which possibly contributes to the wide adaptability and distribution of hexaploid wheat in response to various environmental constraints.

Functional genomics of fuzzless-lintless mutant of Gossypium hirsutum L. cv. MCU5 reveal key genes and pathways involved in cotton fibre initiation and elongation

PubMed Central

2012-01-01

Background Fuzzless-lintless cotton mutants are considered to be the ideal material to understand the molecular mechanisms involved in fibre cell development. Although there are few reports on transcriptome and proteome analyses in cotton at fibre initiation and elongation stages, there is no comprehensive comparative transcriptome analysis of fibre-bearing and fuzzless-lintless cotton ovules covering fibre initiation to secondary cell wall (SCW) synthesis stages. In the present study, a comparative transcriptome analysis was carried out using G. hirsutum L. cv. MCU5 wild-type (WT) and it’s near isogenic fuzzless-lintless (fl) mutant at fibre initiation (0 dpa/days post anthesis), elongation (5, 10 and 15 dpa) and SCW synthesis (20 dpa) stages. Results Scanning electron microscopy study revealed the delay in the initiation of fibre cells and lack of any further development after 2 dpa in the fl mutant. Transcriptome analysis showed major down regulation of transcripts (90%) at fibre initiation and early elongation (5 dpa) stages in the fl mutant. Majority of the down regulated transcripts at fibre initiation stage in the fl mutant represent calcium and phytohormone mediated signal transduction pathways, biosynthesis of auxin and ethylene and stress responsive transcription factors (TFs). Further, transcripts involved in carbohydrate and lipid metabolisms, mitochondrial electron transport system (mETS) and cell wall loosening and elongation were highly down-regulated at fibre elongation stage (5–15 dpa) in the fl mutant. In addition, cellulose synthases and sucrose synthase C were down-regulated at SCW biosynthesis stage (15–20 dpa). Interestingly, some of the transcripts (~50%) involved in phytohormone signalling and stress responsive transcription factors that were up-regulated at fibre initiation stage in the WT were found to be up-regulated at much later stage (15 dpa) in fl mutant. Conclusions Comparative transcriptome analysis of WT and its near isogenic fl mutant revealed key genes and pathways involved at various stages of fibre development. Our data implicated the significant role of mitochondria mediated energy metabolism during fibre elongation process. The delayed expression of genes involved in phytohormone signalling and stress responsive TFs in the fl mutant suggests the need for a coordinated expression of regulatory mechanisms in fibre cell initiation and differentiation. PMID:23151214

Transcriptomics of coping strategies in free-swimming Lepeophtheirus salmonis (Copepoda) larvae responding to abiotic stress.

PubMed

Sutherland, Ben J G; Jantzen, Stuart G; Yasuike, Motoshige; Sanderson, Dan S; Koop, Ben F; Jones, Simon R M

2012-12-01

The salmon louse Lepeophtheirus salmonis is a marine ectoparasite of wild and farmed salmon in the Northern Hemisphere. Infections of farmed salmon are of economic and ecological concern. Nauplius and copepodid salmon lice larvae are free-swimming and disperse in the water column until they encounter a host. In this study, we characterized the sublethal stress responses of L. salmonis copepodid larvae by applying a 38K oligonucleotide microarray to profile transcriptomes following 24 h exposures to suboptimal salinity (30-10 parts per thousand (‰)) or temperature (16-4 °C) environments. Hyposalinity exposure resulted in large-scale gene expression changes relative to those elicited by a thermal gradient. Subsequently, transcriptome responses to a more finely resolved salinity gradient between 30 ‰ and 25 ‰ were profiled. Minimal changes occurred at 29 ‰ or 28 ‰, a threshold of response was identified at 27 ‰, and the largest response was at 25 ‰. Differentially expressed genes were clustered by pattern of expression, and clusters were characterized by functional enrichment analysis. Results indicate larval copepods adopt two distinct coping strategies in response to short-term hyposaline stress: a primary response using molecular chaperones and catabolic processes at 27 ‰; and a secondary response up-regulating ion pumps, transporters, a different suite of chaperones and apoptosis-related transcripts at 26 ‰ and 25 ‰. The results further our understanding of the tolerances of L. salmonis copepodids to salinity and temperature gradients and may assist in the development of salmon louse management strategies. © 2012 Blackwell Publishing Ltd.

De novo Assembly and Analysis of the Chilean Pencil Catfish Trichomycterus areolatus Transcriptome

PubMed Central

Schulze, Thomas T.; Ali, Jonathan M.; Bartlett, Maggie L.; McFarland, Madalyn M.; Clement, Emalie J.; Won, Harim I.; Sanford, Austin G.; Monzingo, Elyssa B.; Martens, Matthew C.; Hemsley, Ryan M.; Kumar, Sidharta; Gouin, Nicolas; Kolok, Alan S.; Davis, Paul H.

2016-01-01

Trichomycterus areolatus is an endemic species of pencil catfish that inhabits the riffles and rapids of many freshwater ecosystems of Chile. Despite its unique adaptation to Chile's high gradient watersheds and therefore potential application in the investigation of ecosystem integrity and environmental contamination, relatively little is known regarding the molecular biology of this environmental sentinel. Here, we detail the assembly of the Trichomycterus areolatus transcriptome, a molecular resource for the study of this organism and its molecular response to the environment. RNA-Seq reads were obtained by next-generation sequencing with an Illumina® platform and processed using PRINSEQ. The transcriptome assembly was performed using TRINITY assembler. Transcriptome validation was performed by functional characterization with KOG, KEGG, and GO analyses. Additionally, differential expression analysis highlights sex-specific expression patterns, and a list of endocrine and oxidative stress related transcripts are included. PMID:27672404

Transcriptomic response to low salinity stress in gills of the Pacific white shrimp, Litopenaeus vannamei.

PubMed

Hu, Dongxu; Pan, Luqing; Zhao, Qun; Ren, Qin

2015-12-01

The Pacific white shrimp, Litopenaeus vannamei (L. vannamei), is one of the most farmed species. Salinity is an important environmental factor that affects its growth and distribution. However, the molecular mechanism of the shrimp in response to salinity stress remains largely unclear. High-throughput sequencing is a helpful tool to analyze the molecular response to salinity challenge in shrimp. In the present study, the transcriptomic responses of the gills in L. vannamei under low salinity stress were detected by Illumina's digital gene expression system. A total of 10,725,789 and 10,827,411 reads were generated from the non-changed and low salinity changed groups, respectively. 64,590 Unigenes with an average length of 764 bp were generated. Compared with the control, 585 genes were differentially expressed under low salinity. GO functional analysis and KEGG pathway analysis indicated some vital genes in response to the challenge. Ten genes related to osmoregulation and ambient salinity adaption were selected to validate the DGE results by RT-qPCR. This work provides valuable information to study the mechanism of salinity adaption in L. vannamei. Genes and pathways from the results will be beneficial to reveal the molecular basis of osmoregulation. It also gives an insight into the response to the salinity challenge in L. vannamei. Copyright © 2015 Elsevier B.V. All rights reserved.

Transcriptome Dynamics in Mango Fruit Peel Reveals Mechanisms of Chilling Stress

PubMed Central

Sivankalyani, Velu; Sela, Noa; Feygenberg, Oleg; Zemach, Hanita; Maurer, Dalia; Alkan, Noam

2016-01-01

Cold storage is considered the most effective method for prolonging fresh produce storage. However, subtropical fruit is sensitive to cold. Symptoms of chilling injury (CI) in mango include red and black spots that start from discolored lenticels and develop into pitting. The response of ‘Keitt’ mango fruit to chilling stress was monitored by transcriptomic, physiological, and microscopic analyses. Transcriptomic changes in the mango fruit peel were evaluated during optimal (12°C) and suboptimal (5°C) cold storage. Two days of chilling stress upregulated genes involved in the plant stress response, including those encoding transmembrane receptors, calcium-mediated signal transduction, NADPH oxidase, MAP kinases, and WRKYs, which can lead to cell death. Indeed, cell death was observed around the discolored lenticels after 19 days of cold storage at 5°C. Localized cell death and cuticular opening in the lumen of discolored lenticels were correlated with increased general decay during shelf-life storage, possibly due to fungal penetration. We also observed increased phenolics accumulation around the discolored lenticels, which was correlated with the biosynthesis of phenylpropanoids that were probably transported from the resin ducts. Increased lipid peroxidation was observed during CI by both the biochemical malondialdehyde method and a new non-destructive luminescent technology, correlated to upregulation of the α-linolenic acid oxidation pathway. Genes involved in sugar metabolism were also induced, possibly to maintain osmotic balance. This analysis provides an in-depth characterization of mango fruit response to chilling stress and could lead to the development of new tools, treatments and strategies to prolong cold storage of subtropical fruit. PMID:27812364

Differential gene expression profiling through transcriptome approach of Saccharum spontaneum L. under low temperature stress reveals genes potentially involved in cold acclimation.

PubMed

Selvarajan, Dharshini; Mohan, Chakravarthi; Dhandapani, Vignesh; Nerkar, Gauri; Jayanarayanan, Ashwin Narayan; Vadakkancherry Mohanan, Manoj; Murugan, Naveenarani; Kaur, Lovejot; Chennappa, Mahadevaiah; Kumar, Ravinder; Meena, Minturam; Ram, Bakshi; Chinnaswamy, Appunu

2018-04-01

Sugarcane ( Saccharum sp.) is predominantly grown in both tropics and subtropics in India, and the subtropics alone contribute more than half of sugarcane production. Sugarcane active growth period in subtropics is restricted to 8-9 months mainly due to winter's low temperature stress prevailing during November to February every year. Being a commercial crop, tolerance to low temperature is important in sugarcane improvement programs. Development of cold tolerant sugarcane varieties require a deep knowledge on molecular mechanism naturally adapted by cold tolerant genotypes during low temperature stress. To understand gene regulation under low temperature stress, control and stressed (10 °C, 24 h) leaf samples of cold tolerant S. spontaneum IND 00-1037 collected from high altitude region in Arunachal Pradesh were used for transcriptome analysis using the Illumina NextSeq 500 platform with paired-end sequencing method. Raw reads of 5.1 GB (control) and 5.3 GB (stressed) obtained were assembled using trinity and annotated with UNIPROT, KEGG, GO, COG and SUCEST databases, and transcriptome was validated using qRT-PCR. The differential gene expression (DGE) analysis showed that 2583 genes were upregulated and 3302 genes were down-regulated upon low temperature stress. A total of 170 cold responsive transcriptional factors belonging to 30 families were differentially regulated. CBF6 (C-binding factor), a DNA binding transcriptional activation protein associated with cold acclimation and freezing tolerance was differentially upregulated. Many low temperature responsive genes involved in various metabolic pathways, viz. cold sensing through membrane fluidity, calcium and lipid signaling genes, MAP kinases, phytohormone signaling and biosynthetic genes, antioxidative enzymes, membrane and cellular stabilizing genes, genes involved in biosynthesis of polyunsaturated fatty acids, chaperones, LEA proteins, soluble sugars, osmoprotectants, lignin and pectin biosynthetic genes were also differentially upregulated. Potential cold responsive genes and transcriptional factors involved in cold tolerance mechanism in cold tolerant S. spontaneum IND 00-1037 were identified. Together, this study provides insights into the cold tolerance to low temperature stress in S. spontaneum , thus opening applications in the genetic improvement of cold stress tolerance in sugarcane.

Characterisation of the Transcriptomes of Genetically Diverse Listeria monocytogenes Exposed to Hyperosmotic and Low Temperature Conditions Reveal Global Stress-Adaptation Mechanisms

PubMed Central

Durack, Juliana; Ross, Tom; Bowman, John P.

2013-01-01

The ability of Listeria monocytogenes to adapt to various food and food- processing environments has been attributed to its robustness, persistence and prevalence in the food supply chain. To improve the present understanding of molecular mechanisms involved in hyperosmotic and low-temperature stress adaptation of L. monocytogenes, we undertook transcriptomics analysis on three strains adapted to sub-lethal levels of these stress stimuli and assessed functional gene response. Adaptation to hyperosmotic and cold-temperature stress has revealed many parallels in terms of gene expression profiles in strains possessing different levels of stress tolerance. Gene sets associated with ribosomes and translation, transcription, cell division as well as fatty acid biosynthesis and peptide transport showed activation in cells adapted to either cold or hyperosmotic stress. Repression of genes associated with carbohydrate metabolism and transport as well as flagella was evident in stressed cells, likely linked to activation of CodY regulon and consequential cellular energy conservation. PMID:24023890

Differential Response to Heat Stress in Outer and Inner Onion Bulb Scales.

PubMed

Galsurker, Ortal; Doron-Faigenboim, Adi; Teper-Bamnolker, Paula; Daus, Avinoam; Lers, Amnon; Eshel, Dani

2018-05-18

Brown protective skin formation in onion bulbs can be induced by rapid postharvest heat treatment. Onions that were peeled to different depths and were exposed to heat stress showed that only the outer scale formed dry brown skin, whereas the inner scales maintained high water content and did not change color. Our results reveal that browning of the outer scale during heat treatment is due to an enzymatic process that is associated with high levels of oxidation components, such as peroxidase and quercetin glucoside. De-novo transcriptome analysis revealed differential molecular responses of the outer and inner scales to the heat stress. Genes involved in lipid metabolism, oxidation pathways and cell-wall modification were highly expressed in the outer scale during heating. Defense-response-related genes such as those encoding heat-shock proteins, antioxidative stress defense or production of osmoprotectant metabolites were mostly induced in the inner scale in response to the heat exposure. These transcriptomic data led to a conceptual model that suggests sequential processes for browning development and desiccation of the outer scales versus processes associated with defense response and heat tolerance in the inner scale. Thus, the observed physiological differences between the outer and inner scales is supported by the identified molecular differences.

Comparative Transcriptomic and Phenotypic Analysis of the Responses of Bacillus cereus to Various Disinfectant Treatments▿ †

PubMed Central

Ceragioli, Mara; Mols, Maarten; Moezelaar, Roy; Ghelardi, Emilia; Senesi, Sonia; Abee, Tjakko

2010-01-01

Antimicrobial chemicals are widely applied to clean and disinfect food-contacting surfaces. However, the cellular response of bacteria to various disinfectants is unclear. In this study, the physiological and genome-wide transcriptional responses of Bacillus cereus ATCC 14579 exposed to four different disinfectants (benzalkonium chloride, sodium hypochlorite, hydrogen peroxide, and peracetic acid) were analyzed. For each disinfectant, concentrations leading to the attenuation of growth, growth arrest, and cell death were determined. The transcriptome analysis revealed that B. cereus, upon exposure to the selected concentrations of disinfectants, induced common and specific responses. Notably, the common response included genes involved in the general and oxidative stress responses. Exposure to benzalkonium chloride, a disinfectant known to induce membrane damage, specifically induced genes involved in fatty acid metabolism. Membrane damage induced by benzalkonium chloride was confirmed by fluorescence microscopy, and fatty acid analysis revealed modulation of the fatty acid composition of the cell membrane. Exposure to sodium hypochlorite induced genes involved in metabolism of sulfur and sulfur-containing amino acids, which correlated with the excessive oxidation of sulfhydryl groups observed in sodium hypochlorite-stressed cells. Exposures to hydrogen peroxide and peracetic acid induced highly similar responses, including the upregulation of genes involved in DNA damage repair and SOS response. Notably, hydrogen peroxide- and peracetic acid-treated cells exhibited high mutation rates correlating with the induced SOS response. PMID:20348290

Abiotic Stresses Modulate Landscape of Poplar Transcriptome via Alternative Splicing, Differential Intron Retention, and Isoform Ratio Switching

PubMed Central

Filichkin, Sergei A.; Hamilton, Michael; Dharmawardhana, Palitha D.; Singh, Sunil K.; Sullivan, Christopher; Ben-Hur, Asa; Reddy, Anireddy S. N.; Jaiswal, Pankaj

2018-01-01

Abiotic stresses affect plant physiology, development, growth, and alter pre-mRNA splicing. Western poplar is a model woody tree and a potential bioenergy feedstock. To investigate the extent of stress-regulated alternative splicing (AS), we conducted an in-depth survey of leaf, root, and stem xylem transcriptomes under drought, salt, or temperature stress. Analysis of approximately one billion of genome-aligned RNA-Seq reads from tissue- or stress-specific libraries revealed over fifteen millions of novel splice junctions. Transcript models supported by both RNA-Seq and single molecule isoform sequencing (Iso-Seq) data revealed a broad array of novel stress- and/or tissue-specific isoforms. Analysis of Iso-Seq data also resulted in the discovery of 15,087 novel transcribed regions of which 164 show AS. Our findings demonstrate that abiotic stresses profoundly perturb transcript isoform profiles and trigger widespread intron retention (IR) events. Stress treatments often increased or decreased retention of specific introns – a phenomenon described here as differential intron retention (DIR). Many differentially retained introns were regulated in a stress- and/or tissue-specific manner. A subset of transcripts harboring super stress-responsive DIR events showed persisting fluctuations in the degree of IR across all treatments and tissue types. To investigate coordinated dynamics of intron-containing transcripts in the study we quantified absolute copy number of isoforms of two conserved transcription factors (TFs) using Droplet Digital PCR. This case study suggests that stress treatments can be associated with coordinated switches in relative ratios between fully spliced and intron-retaining isoforms and may play a role in adjusting transcriptome to abiotic stresses. PMID:29483921

A Transcriptomic Comparison of Two Bambara Groundnut Landraces under Dehydration Stress

PubMed Central

Khan, Faraz; Chai, Hui Hui; Ajmera, Ishan; Hodgman, Charlie; Mayes, Sean; Lu, Chungui

2017-01-01

The ability to grow crops under low-water conditions is a significant advantage in relation to global food security. Bambara groundnut is an underutilised crop grown by subsistence farmers in Africa and is known to survive in regions of water deficit. This study focuses on the analysis of the transcriptomic changes in two bambara groundnut landraces in response to dehydration stress. A cross-species hybridisation approach based on the Soybean Affymetrix GeneChip array has been employed. The differential gene expression analysis of a water-limited treatment, however, showed that the two landraces responded with almost completely different sets of genes. Hence, both landraces with very similar genotypes (as assessed by the hybridisation of genomic DNA onto the Soybean Affymetrix GeneChip) showed contrasting transcriptional behaviour in response to dehydration stress. In addition, both genotypes showed a high expression of dehydration-associated genes, even under water-sufficient conditions. Several gene regulators were identified as potentially important. Some are already known, such as WRKY40, but others may also be considered, namely PRR7, ATAUX2-11, CONSTANS-like 1, MYB60, AGL-83, and a Zinc-finger protein. These data provide a basis for drought trait research in the bambara groundnut, which will facilitate functional genomics studies. An analysis of this dataset has identified that both genotypes appear to be in a dehydration-ready state, even in the absence of dehydration stress, and may have adapted in different ways to achieve drought resistance. This will help in understanding the mechanisms underlying the ability of crops to produce viable yields under drought conditions. In addition, cross-species hybridisation to the soybean microarray has been shown to be informative for investigating the bambara groundnut transcriptome. PMID:28420201

Transcriptomic analysis of rice aleurone cells identified a novel abscisic acid response element.

PubMed

Watanabe, Kenneth A; Homayouni, Arielle; Gu, Lingkun; Huang, Kuan-Ying; Ho, Tuan-Hua David; Shen, Qingxi J

2017-09-01

Seeds serve as a great model to study plant responses to drought stress, which is largely mediated by abscisic acid (ABA). The ABA responsive element (ABRE) is a key cis-regulatory element in ABA signalling. However, its consensus sequence (ACGTG(G/T)C) is present in the promoters of only about 40% of ABA-induced genes in rice aleurone cells, suggesting other ABREs may exist. To identify novel ABREs, RNA sequencing was performed on aleurone cells of rice seeds treated with 20 μM ABA. Gibbs sampling was used to identify enriched elements, and particle bombardment-mediated transient expression studies were performed to verify the function. Gene ontology analysis was performed to predict the roles of genes containing the novel ABREs. This study revealed 2443 ABA-inducible genes and a novel ABRE, designated as ABREN, which was experimentally verified to mediate ABA signalling in rice aleurone cells. Many of the ABREN-containing genes are predicted to be involved in stress responses and transcription. Analysis of other species suggests that the ABREN may be monocot specific. This study also revealed interesting expression patterns of genes involved in ABA metabolism and signalling. Collectively, this study advanced our understanding of diverse cis-regulatory sequences and the transcriptomes underlying ABA responses in rice aleurone cells. © 2017 John Wiley & Sons Ltd.

Acute hypoxia stress induced abundant differential expression genes and alternative splicing events in heart of tilapia.

PubMed

Xia, Jun Hong; Li, Hong Lian; Li, Bi Jun; Gu, Xiao Hui; Lin, Hao Ran

2018-01-10

Hypoxia is one of the critical environmental stressors for fish in aquatic environments. Although accumulating evidences indicate that gene expression is regulated by hypoxia stress in fish, how genes undergoing differential gene expression and/or alternative splicing (AS) in response to hypoxia stress in heart are not well understood. Using RNA-seq, we surveyed and detected 289 differential expressed genes (DEG) and 103 genes that undergo differential usage of exons and splice junctions events (DUES) in heart of a hypoxia tolerant fish, Nile tilapia, Oreochromis niloticus following 12h hypoxic treatment. The spatio-temporal expression analysis validated the significant association of differential exon usages in two randomly selected DUES genes (fam162a and ndrg2) in 5 tissues (heart, liver, brain, gill and spleen) sampled at three time points (6h, 12h, and 24h) under acute hypoxia treatment. Functional analysis significantly associated the differential expressed genes with the categories related to energy conservation, protein synthesis and immune response. Different enrichment categories were found between the DEG and DUES dataset. The Isomerase activity, Oxidoreductase activity, Glycolysis and Oxidative stress process were significantly enriched for the DEG gene dataset, but the Structural constituent of ribosome and Structural molecule activity, Ribosomal protein and RNA binding protein were significantly enriched only for the DUES genes. Our comparative transcriptomic analysis reveals abundant stress responsive genes and their differential regulation function in the heart tissues of Nile tilapia under acute hypoxia stress. Our findings will facilitate future investigation on transcriptome complexity and AS regulation during hypoxia stress in fish. Copyright © 2017 Elsevier B.V. All rights reserved.

Global Transcriptional Analysis Reveals the Complex Relationship between Tea Quality, Leaf Senescence and the Responses to Cold-Drought Combined Stress in Camellia sinensis

PubMed Central

Zheng, Chao; Wang, Yu; Ding, Zhaotang; Zhao, Lei

2016-01-01

In field conditions, especially in arid and semi-arid areas, tea plants are often simultaneously exposed to various abiotic stresses such as cold and drought, which have profound effects on leaf senescence process and tea quality. However, most studies of gene expression in stress responses focus on a single inciting agent, and the confounding effect of multiple stresses on crop quality and leaf senescence remain unearthed. Here, global transcriptome profiles of tea leaves under separately cold and drought stress were compared with their combination using RNA-Seq technology. This revealed that tea plants shared a large overlap in unigenes displayed “similar” (26%) expression pattern and avoid antagonistic responses (lowest level of “prioritized” mode: 0%) to exhibit very congruent responses to co-occurring cold and drought stress; 31.5% differential expressed genes and 38% of the transcriptome changes in response to combined stresses were unpredictable from cold or drought single-case studies. We also identified 319 candidate genes for enhancing plant resistance to combined stress. We then investigated the combined effect of cold and drought on tea quality and leaf senescence. Our results showed that drought-induced leaf senescence were severely delayed by (i) modulation of a number of senescence-associated genes and cold responsive genes, (ii) enhancement of antioxidant capacity, (iii) attenuation of lipid degradation, (iv) maintenance of cell wall and photosynthetic system, (v) alteration of senescence-induced sugar effect/sensitivity, as well as (vi) regulation of secondary metabolism pathways that significantly influence the quality of tea during combined stress. Therefore, care should be taken when utilizing a set of stresses to try and maximize leaf longevity and tea quality. PMID:28018394

De novo transcriptome sequencing and comprehensive analysis of the heat stress response genes in the basidiomycetes fungus Ganoderma lucidum.

PubMed

Tan, Xiaoyan; Sun, Junshe; Ning, Huijuan; Qin, Zifang; Miao, Yuxin; Sun, Tian; Zhang, Xiuqing

2018-06-30

Ganoderma lucidum is a valuable basidiomycete with numerous pharmacological compounds, which is widely consumed throughout China. We previously found that the polysaccharide content of Ganoderma lucidum fruiting bodies could be significantly improved by 45.63% with treatment of 42 °C heat stress (HS) for 2 h. To further investigate genes involved in HS response and explore the mechanisms of HS regulating the carbohydrate metabolism in Ganoderma lucidum, high-throughput RNA-Seq was conducted to analyse the difference between control and heat-treated mycelia at transcriptome level. We sequenced six cDNA libraries with three from control group (mycelia cultivated at 28 °C) and three from heat-treated group (mycelia subjected to 42 °C for 2 h). A total of 99,899 transcripts were generated using Trinity method and 59,136 unigenes were annotated by seven public databases. Among them, 2790 genes were identified to be differential expressed genes (DEGs) under HS condition, which included 1991 up-regulated and 799 down-regulated. 176 DEGs were then manually classified into five main responsive-related categories according to their putative functions and possible metabolic pathways. These groups include stress resistance-related factors; protein assembly, transportation and degradation; signal transduction; carbohydrate metabolism and energy provision-related process; other related functions, suggesting that a series of metabolic pathways in Ganoderma lucidum are activated by HS and the response mechanism involves a complex molecular network which needs further study. Remarkably, 48 DEGs were found to regulate carbohydrate metabolism, both in carbohydrate hydrolysis for energy provision and polysaccharide synthesis. In summary, this comprehensive transcriptome analysis will provide enlarged resource for further investigation into the molecular mechanisms of basidiomycete under HS condition. Copyright © 2018 Elsevier B.V. All rights reserved.

Day and night heat stress trigger different transcriptomic responses in green and ripening grapevine (vitis vinifera) fruit

PubMed Central

2014-01-01

Background Global climate change will noticeably affect plant vegetative and reproductive development. The recent increase in temperatures has already impacted yields and composition of berries in many grapevine-growing regions. Physiological processes underlying temperature response and tolerance of the grapevine fruit have not been extensively investigated. To date, all studies investigating the molecular regulation of fleshly fruit response to abiotic stress were only conducted during the day, overlooking possible critical night-specific variations. The present study explores the night and day transcriptomic response of grapevine fruit to heat stress at several developmental stages. Short heat stresses (2 h) were applied at day and night to vines bearing clusters sequentially ordered according to the developmental stages along their vertical axes. The recently proposed microvine model (DRCF-Dwarf Rapid Cycling and Continuous Flowering) was grown in climatic chambers in order to circumvent common constraints and biases inevitable in field experiments with perennial macrovines. Post-véraison berry heterogeneity within clusters was avoided by constituting homogenous batches following organic acids and sugars measurements of individual berries. A whole genome transcriptomic approach was subsequently conducted using NimbleGen 090818 Vitis 12X (30 K) microarrays. Results Present work reveals significant differences in heat stress responsive pathways according to day or night treatment, in particular regarding genes associated with acidity and phenylpropanoid metabolism. Precise distinction of ripening stages led to stage-specific detection of malic acid and anthocyanin-related transcripts modulated by heat stress. Important changes in cell wall modification related processes as well as indications for heat-induced delay of ripening and sugar accumulation were observed at véraison, an effect that was reversed at later stages. Conclusions This first day - night study on heat stress adaption of the grapevine berry shows that the transcriptome of fleshy fruits is differentially affected by abiotic stress at night. The present results emphasize the necessity of including different developmental stages and especially several daytime points in transcriptomic studies. PMID:24774299

Transcriptome analysis of lentil (Lens culinaris Medikus) in response to seedling drought stress.

PubMed

Singh, Dharmendra; Singh, Chandan Kumar; Taunk, Jyoti; Tomar, Ram Sewak Singh; Chaturvedi, Ashish Kumar; Gaikwad, Kishor; Pal, Madan

2017-02-27

Drought stress is one of the most harmful abiotic stresses in crop plants. As a moderately drought tolerant crop, lentil is a major crop in rainfed areas and a suitable candidate for drought stress tolerance research work. Screening for drought tolerance stress under hydroponic conditions at seedling stage with air exposure is an efficient technique to select genotypes with contrasting traits. Transcriptome analysis provides valuable resources, especially for lentil, as here the information on complete genome sequence is not available. Hence, the present studies were carried out. This study was undertaken to understand the biochemical mechanisms and transcriptome changes involved in imparting adaptation to drought stress at seedling stage in drought-tolerant (PDL-2) and drought-sensitive (JL-3) cultivars. Among different physiological and biochemical parameters, a significant increase was recorded in proline, glycine betaine contents and activities of SOD, APX and GPX in PDL-2 compared to JL-3while chlorophyll, RWC and catalase activity decreased significantly in JL-3. Transcriptome changes between the PDL-2 and JL-3 under drought stress were evaluated using Illumina HiSeq 2500 platform. Total number of bases ranged from 5.1 to 6.7 Gb. Sequence analysis of control and drought treated cDNA libraries of PDL-2 and JL-3 produced 74032, 75500, 78328 and 81523 contigs, respectively with respective N50 value of 2011, 2008, 2000 and 1991. Differential gene expression of drought treated genotypes along with their controls revealed a total of 11,435 upregulated and 6,934 downregulated transcripts. For functional classification of DEGs, KEGG pathway annotation analysis extracted a total of 413 GO annotation terms where 176 were within molecular process, 128 in cellular and 109 in biological process groups. The transcriptional profiles provide a foundation for deciphering the underlying mechanism for drought tolerance in lentil. Transcriptional regulation, signal transduction and secondary metabolism in two genotypes revealed significant differences at seedling stage under severe drought. Our finding suggests role of candidate genes for improving drought tolerance in lentil.

Salt-Responsive Transcriptome Profiling of Suaeda glauca via RNA Sequencing

PubMed Central

Jin, Hangxia; Dong, Dekun; Yang, Qinghua; Zhu, Danhua

2016-01-01

Background Suaeda glauca, a succulent halophyte of the Chenopodiaceae family, is widely distributed in coastal areas of China. Suaeda glauca is highly resistant to salt and alkali stresses. In the present study, the salt-responsive transcriptome of Suaeda glauca was analyzed to identify genes involved in salt tolerance and study halophilic mechanisms in this halophyte. Results Illumina HiSeq 2500 was used to sequence cDNA libraries from salt-treated and control samples with three replicates each treatment. De novo assembly of the six transcriptomes identified 75,445 unigenes. A total of 23,901 (31.68%) unigenes were annotated. Compared with transcriptomes from the three salt-treated and three salt-free samples, 231 differentially expressed genes (DEGs) were detected (including 130 up-regulated genes and 101 down-regulated genes), and 195 unigenes were functionally annotated. Based on the Gene Ontology (GO), Clusters of Orthologous Groups (COG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) classifications of the DEGs, more attention should be paid to transcripts associated with signal transduction, transporters, the cell wall and growth, defense metabolism and transcription factors involved in salt tolerance. Conclusions This report provides a genome-wide transcriptional analysis of a halophyte, Suaeda glauca, under salt stress. Further studies of the genetic basis of salt tolerance in halophytes are warranted. PMID:26930632

Transcriptomic studies reveal a key metabolic pathway contributing to a well-maintained photosynthetic system under drought stress in foxtail millet (Setaria italica L.).

PubMed

Shi, Weiping; Cheng, Jingye; Wen, Xiaojie; Wang, Jixiang; Shi, Guanyan; Yao, Jiayan; Hou, Liyuan; Sun, Qian; Xiang, Peng; Yuan, Xiangyang; Dong, Shuqi; Guo, Pingyi; Guo, Jie

2018-01-01

Drought stress is one of the most important abiotic factors limiting crop productivity. A better understanding of the effects of drought on millet ( Setaria italica L.) production, a model crop for studying drought tolerance, and the underlying molecular mechanisms responsible for drought stress responses is vital to improvement of agricultural production. In this study, we exposed the drought resistant F 1 hybrid, M79, and its parental lines E1 and H1 to drought stress. Subsequent physiological analysis demonstrated that M79 showed higher photosynthetic energy conversion efficiency and drought tolerance than its parents. A transcriptomic study using leaves collected six days after drought treatment, when the soil water content was about ∼20%, identified 3066, 1895, and 2148 differentially expressed genes (DEGs) in M79, E1 and H1 compared to the respective untreated controls, respectively. Further analysis revealed 17 Gene Ontology (GO) enrichments and 14 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways in M79, including photosystem II (PSII) oxygen-evolving complex, peroxidase (POD) activity, plant hormone signal transduction, and chlorophyll biosynthesis. Co-regulation analysis suggested that these DEGs in M79 contributed to the formation of a regulatory network involving multiple biological processes and pathways including photosynthesis, signal transduction, transcriptional regulation, redox regulation, hormonal signaling, and osmotic regulation. RNA-seq analysis also showed that some photosynthesis-related DEGs were highly expressed in M79 compared to its parental lines under drought stress. These results indicate that various molecular pathways, including photosynthesis, respond to drought stress in M79, and provide abundant molecular information for further analysis of the underlying mechanism responding to this stress.

A transcriptomic analysis of bermudagrass (Cynodon dactylon) provides novel insights into the basis of low temperature tolerance.

PubMed

Chen, Liang; Fan, Jibiao; Hu, Longxing; Hu, Zhengrong; Xie, Yan; Zhang, Yingzi; Lou, Yanhong; Nevo, Eviatar; Fu, Jinmin

2015-09-11

Cold stress is regarded as a key factor limiting widespread use for bermudagrass (Cynodon dactylon). Therefore, to improve cold tolerance for bermudagrass, it is urgent to understand molecular mechanisms of bermudagrass response to cold stress. However, our knowledge about the molecular responses of this species to cold stress is largely unknown. The objective of this study was to characterize the transcriptomic response to low temperature in bermudagrass by using RNA-Seq platform. Ten cDNA libraries were generated from RNA samples of leaves from five different treatments in the cold-resistant (R) and the cold-sensitive (S) genotypes, including 4 °C cold acclimation (CA) for 24 h and 48 h, freezing (-5 °C) treatments for 4 h with or without prior CA, and controls. When subjected to cold acclimation, global gene expressions were initiated more quickly in the R genotype than those in the S genotype. The R genotype activated gene expression more effectively in response to freezing temperature after 48 h CA than the S genotype. The differentially expressed genes were identified as low temperature sensing and signaling-related genes, functional proteins and transcription factors, many of which were specifically or predominantly expressed in the R genotype under cold treatments, implying that these genes play important roles in the enhanced cold hardiness of bermudagrass. KEGG pathway enrichment analysis for DEGs revealed that photosynthesis, nitrogen metabolism and carbon fixation pathways play key roles in bermudagrass response to cold stress. The results of this study may contribute to our understanding the molecular mechanism underlying the responses of bermudagrass to cold stress, and also provide important clues for further study and in-depth characterization of cold-resistance breeding candidate genes in bermudagrass.

Characterization of expressed sequence tags (ESTs) of pigeonpea (Cajanus cajan L.) and functional validation of selected genes for abiotic stress tolerance in Arabidopsis thaliana.

PubMed

Priyanka, B; Sekhar, K; Sunita, T; Reddy, V D; Rao, Khareedu Venkateswara

2010-03-01

Pigeonpea, a major grain legume crop with remarkable drought tolerance traits, has been used for the isolation of stress-responsive genes. Herein, we report generation of ESTs, transcript profiles of selected genes and validation of candidate genes obtained from the subtracted cDNA libraries of pigeonpea plants subjected to PEG/water-deficit stress conditions. Cluster analysis of 124 selected ESTs yielded 75 high-quality ESTs. Homology searches disclosed that 55 ESTs share significant similarity with the known/putative proteins or ESTs available in the databases. These ESTs were characterized and genes relevant to the specific physiological processes were identified. Of the 75 ESTs obtained from the cDNA libraries of drought-stressed plants, 20 ESTs proved to be unique to the pigeonpea. These sequences are envisaged to serve as a potential source of stress-inducible genes of the drought stress-response transcriptome, and hence may be used for deciphering the mechanism of drought tolerance of the pigeonpea. Expression profiles of selected genes revealed increased levels of m-RNA transcripts in pigeonpea plants subjected to different abiotic stresses. Transgenic Arabidopsis lines, expressing Cajanus cajan hybrid-proline-rich protein (CcHyPRP), C. cajan cyclophilin (CcCYP) and C. cajan cold and drought regulatory (CcCDR) genes, exhibited marked tolerance, increased plant biomass and enhanced photosynthetic rates under PEG/NaCl/cold/heat stress conditions. This study represents the first report dealing with the isolation of drought-specific ESTs, transcriptome analysis and functional validation of drought-responsive genes of the pigeonpea. These genes, as such, hold promise for engineering crop plants bestowed with tolerance to major abiotic stresses.

Transcriptome Analysis of Arabidopsis GCR1 Mutant Reveals Its Roles in Stress, Hormones, Secondary Metabolism and Phosphate Starvation

PubMed Central

Chakraborty, Navjyoti; Sharma, Priyanka; Kanyuka, Kostya; Pathak, Ravi R.; Choudhury, Devapriya; Hooley, Richard A.; Raghuram, Nandula

2015-01-01

The controversy over the existence or the need for G-protein coupled receptors (GPCRs) in plant G-protein signalling has overshadowed a more fundamental quest for the role of AtGCR1, the most studied and often considered the best candidate for GPCR in plants. Our whole transcriptome microarray analysis of the GCR1-knock-out mutant (gcr1-5) in Arabidopsis thaliana revealed 350 differentially expressed genes spanning all chromosomes. Many of them were hitherto unknown in the context of GCR1 or G-protein signalling, such as in phosphate starvation, storage compound and fatty acid biosynthesis, cell fate, etc. We also found some GCR1-responsive genes/processes that are reported to be regulated by heterotrimeric G-proteins, such as biotic and abiotic stress, hormone response and secondary metabolism. Thus, GCR1 could have G-protein-mediated as well as independent roles and regardless of whether it works as a GPCR, further analysis of the organism-wide role of GCR1 has a significance of its own. PMID:25668726

Transcriptome sequencing analysis of novel sRNAs of Kineococcus radiotolerans in response to ionizing radiation.

PubMed

Chen, Zhouwei; Li, Lufeng; Shan, Zhan; Huang, Hannian; Chen, Huan; Ding, Xianfeng; Guo, Jiangfeng; Liu, Lili

2016-11-01

Kineococcus radiotolerans is a Gram-positive, radio-resistant bacterium isolated from a radioactive environment. The small noncoding RNAs (sRNAs) in bacteria are reported to play roles in the immediate response to stress and/or the recovery from stress. The analysis of K. radiotolerans transcriptome sequencing results can identify these sRNAs in a genome-wide detection, using RNA sequencing (RNA-seq) by the deep sequencing technique. In this study, the raw data of radiation-exposed samples (RS) and control samples (CS) were acquired separately from the sequencing platform. There were 217 common sRNA candidates in the two samples screened in the genome-wide scale by bioinformatics analysis. There were 43 differentially expressed sRNA candidates, including 28 up-regulated and 15 down-regulated ones. The down-regulated sRNAs were selected for the sRNA target prediction, of which 12 sRNAs that may modulate the genes related to the transcription regulation and DNA repair were considered as the candidates involved in the radio-resistance regulation system. Copyright © 2016 Elsevier GmbH. All rights reserved.

Comparative transcriptome analysis of Aspergillus flavus isolates under different oxidative stresses and culture media

USDA-ARS?s Scientific Manuscript database

Aspergillus flavus and aflatoxin contamination in the field are known to be influenced by numerous stress factors, particularly drought and heat stress. However, the purpose of aflatoxin production is unknown. Here, we report transcriptome analyses comprised of 282.6 Gb of sequencing data describing...

Functional genomics of pH homeostasis in Corynebacterium glutamicum revealed novel links between pH response, oxidative stress, iron homeostasis and methionine synthesis

PubMed Central

2009-01-01

Background The maintenance of internal pH in bacterial cells is challenged by natural stress conditions, during host infection or in biotechnological production processes. Comprehensive transcriptomic and proteomic analyses has been conducted in several bacterial model systems, yet questions remain as to the mechanisms of pH homeostasis. Results Here we present the comprehensive analysis of pH homeostasis in C. glutamicum, a bacterium of industrial importance. At pH values between 6 and 9 effective maintenance of the internal pH at 7.5 ± 0.5 pH units was found. By DNA microarray analyses differential mRNA patterns were identified. The expression profiles were validated and extended by 1D-LC-ESI-MS/MS based quantification of soluble and membrane proteins. Regulators involved were identified and thereby participation of numerous signaling modules in pH response was found. The functional analysis revealed for the first time the occurrence of oxidative stress in C. glutamicum cells at neutral and low pH conditions accompanied by activation of the iron starvation response. Intracellular metabolite pool analysis unraveled inhibition of the TCA and other pathways at low pH. Methionine and cysteine synthesis were found to be activated via the McbR regulator, cysteine accumulation was observed and addition of cysteine was shown to be toxic under acidic conditions. Conclusions Novel limitations for C. glutamicum at non-optimal pH values were identified by a comprehensive analysis on the level of the transcriptome, proteome, and metabolome indicating a functional link between pH acclimatization, oxidative stress, iron homeostasis, and metabolic alterations. The results offer new insights into bacterial stress physiology and new starting points for bacterial strain design or pathogen defense. PMID:20025733

Transcriptomics-based analysis using RNA-Seq of the coconut (Cocos nucifera) leaf in response to yellow decline phytoplasma infection.

PubMed

Nejat, Naghmeh; Cahill, David M; Vadamalai, Ganesan; Ziemann, Mark; Rookes, James; Naderali, Neda

2015-10-01

Invasive phytoplasmas wreak havoc on coconut palms worldwide, leading to high loss of income, food insecurity and extreme poverty of farmers in producing countries. Phytoplasmas as strictly biotrophic insect-transmitted bacterial pathogens instigate distinct changes in developmental processes and defence responses of the infected plants and manipulate plants to their own advantage; however, little is known about the cellular and molecular mechanisms underlying host-phytoplasma interactions. Further, phytoplasma-mediated transcriptional alterations in coconut palm genes have not yet been identified. This study evaluated the whole transcriptome profiles of naturally infected leaves of Cocos nucifera ecotype Malayan Red Dwarf in response to yellow decline phytoplasma from group 16SrXIV, using RNA-Seq technique. Transcriptomics-based analysis reported here identified genes involved in coconut innate immunity. The number of down-regulated genes in response to phytoplasma infection exceeded the number of genes up-regulated. Of the 39,873 differentially expressed unigenes, 21,860 unigenes were suppressed and 18,013 were induced following infection. Comparative analysis revealed that genes associated with defence signalling against biotic stimuli were significantly overexpressed in phytoplasma-infected leaves versus healthy coconut leaves. Genes involving cell rescue and defence, cellular transport, oxidative stress, hormone stimulus and metabolism, photosynthesis reduction, transcription and biosynthesis of secondary metabolites were differentially represented. Our transcriptome analysis unveiled a core set of genes associated with defence of coconut in response to phytoplasma attack, although several novel defence response candidate genes with unknown function have also been identified. This study constitutes valuable sequence resource for uncovering the resistance genes and/or susceptibility genes which can be used as genetic tools in disease resistance breeding.

Seasonal and latitudinal acclimatization of cardiac transcriptome responses to thermal stress in porcelain crabs, Petrolisthes cinctipes.

PubMed

Stillman, Jonathon H; Tagmount, Abderrahmane

2009-10-01

Central predictions of climate warming models include increased climate variability and increased severity of heat waves. Physiological acclimatization in populations across large-scale ecological gradients in habitat temperature fluctuation is an important factor to consider in detecting responses to climate change related increases in thermal fluctuation. We measured in vivo cardiac thermal maxima and used microarrays to profile transcriptome heat and cold stress responses in cardiac tissue of intertidal zone porcelain crabs across biogeographic and seasonal gradients in habitat temperature fluctuation. We observed acclimatization dependent induction of heat shock proteins, as well as unknown genes with heat shock protein-like expression profiles. Thermal acclimatization had the largest effect on heat stress responses of extensin-like, beta tubulin, and unknown genes. For these genes, crabs acclimatized to thermally variable sites had higher constitutive expression than specimens from low variability sites, but heat stress dramatically induced expression in specimens from low variability sites and repressed expression in specimens from highly variable sites. Our application of ecological transcriptomics has yielded new biomarkers that may represent sensitive indicators of acclimatization to habitat temperature fluctuation. Our study also has identified novel genes whose further description may yield novel understanding of cellular responses to thermal acclimatization or thermal stress.

Physiological Investigation and Transcriptome Analysis of Polyethylene Glycol (PEG)-Induced Dehydration Stress in Cassava.

PubMed

Fu, Lili; Ding, Zehong; Han, Bingying; Hu, Wei; Li, Yajun; Zhang, Jiaming

2016-02-25

Cassava is an important tropical and sub-tropical root crop that is adapted to drought environment. However, severe drought stress significantly influences biomass accumulation and starchy root production. The mechanism underlying drought-tolerance remains obscure in cassava. In this study, changes of physiological characters and gene transcriptome profiles were investigated under dehydration stress simulated by polyethylene glycol (PEG) treatments. Five traits, including peroxidase (POD) activity, proline content, malondialdehyde (MDA), soluble sugar and soluble protein, were all dramatically induced in response to PEG treatment. RNA-seq analysis revealed a gradient decrease of differentially expressed (DE) gene number in tissues from bottom to top of a plant, suggesting that cassava root has a quicker response and more induced/depressed DE genes than leaves in response to drought. Overall, dynamic changes of gene expression profiles in cassava root and leaves were uncovered: genes related to glycolysis, abscisic acid and ethylene biosynthesis, lipid metabolism, protein degradation, and second metabolism of flavonoids were significantly induced, while genes associated with cell cycle/organization, cell wall synthesis and degradation, DNA synthesis and chromatin structure, protein synthesis, light reaction of photosynthesis, gibberelin pathways and abiotic stress were greatly depressed. Finally, novel pathways in ABA-dependent and ABA-independent regulatory networks underlying PEG-induced dehydration response in cassava were detected, and the RNA-Seq results of a subset of fifteen genes were confirmed by real-time PCR. The findings will improve our understanding of the mechanism related to dehydration stress-tolerance in cassava and will provide useful candidate genes for breeding of cassava varieties better adapted to drought environment.

Physiological Investigation and Transcriptome Analysis of Polyethylene Glycol (PEG)-Induced Dehydration Stress in Cassava

PubMed Central

Fu, Lili; Ding, Zehong; Han, Bingying; Hu, Wei; Li, Yajun; Zhang, Jiaming

2016-01-01

Cassava is an important tropical and sub-tropical root crop that is adapted to drought environment. However, severe drought stress significantly influences biomass accumulation and starchy root production. The mechanism underlying drought-tolerance remains obscure in cassava. In this study, changes of physiological characters and gene transcriptome profiles were investigated under dehydration stress simulated by polyethylene glycol (PEG) treatments. Five traits, including peroxidase (POD) activity, proline content, malondialdehyde (MDA), soluble sugar and soluble protein, were all dramatically induced in response to PEG treatment. RNA-seq analysis revealed a gradient decrease of differentially expressed (DE) gene number in tissues from bottom to top of a plant, suggesting that cassava root has a quicker response and more induced/depressed DE genes than leaves in response to drought. Overall, dynamic changes of gene expression profiles in cassava root and leaves were uncovered: genes related to glycolysis, abscisic acid and ethylene biosynthesis, lipid metabolism, protein degradation, and second metabolism of flavonoids were significantly induced, while genes associated with cell cycle/organization, cell wall synthesis and degradation, DNA synthesis and chromatin structure, protein synthesis, light reaction of photosynthesis, gibberelin pathways and abiotic stress were greatly depressed. Finally, novel pathways in ABA-dependent and ABA-independent regulatory networks underlying PEG-induced dehydration response in cassava were detected, and the RNA-Seq results of a subset of fifteen genes were confirmed by real-time PCR. The findings will improve our understanding of the mechanism related to dehydration stress-tolerance in cassava and will provide useful candidate genes for breeding of cassava varieties better adapted to drought environment. PMID:26927071

Transcriptome analysis of a wild bird reveals physiological responses to the urban environment

PubMed Central

Watson, Hannah; Videvall, Elin; Andersson, Martin N.; Isaksson, Caroline

2017-01-01

Identifying the molecular basis of environmentally induced phenotypic variation presents exciting opportunities for furthering our understanding of how ecological processes and the environment can shape the phenotype. Urban and rural environments present free-living organisms with different challenges and opportunities, which have marked consequences for the phenotype, yet little is known about responses at the molecular level. We characterised transcriptomes from an urban and a rural population of great tits Parus major, demonstrating striking differences in gene expression profiles in both blood and liver tissues. Differentially expressed genes had functions related to immune and inflammatory responses, detoxification, protection against oxidative stress, lipid metabolism, and regulation of gene expression. Many genes linked to stress responses were expressed at higher levels in the urban birds, in accordance with our prediction that urban animals are exposed to greater environmental stress. This is one of the first studies to reveal transcriptional differences between urban- and rural-dwelling animals and suggests an important role for epigenetics in mediating environmentally induced physiological variation. The study provides valuable resources for developing further in-depth studies of the mechanisms driving phenotypic variation in the urban context at larger spatial and temporal scales. PMID:28290496

Transcriptome profiling of a Saccharomyces cerevisiae mutant with a constitutively activated Ras/cAMP pathway.

PubMed

Jones, D L; Petty, J; Hoyle, D C; Hayes, A; Ragni, E; Popolo, L; Oliver, S G; Stateva, L I

2003-12-16

Often changes in gene expression levels have been considered significant only when above/below some arbitrarily chosen threshold. We investigated the effect of applying a purely statistical approach to microarray analysis and demonstrated that small changes in gene expression have biological significance. Whole genome microarray analysis of a pde2Delta mutant, constructed in the Saccharomyces cerevisiae reference strain FY23, revealed altered expression of approximately 11% of protein encoding genes. The mutant, characterized by constitutive activation of the Ras/cAMP pathway, has increased sensitivity to stress, reduced ability to assimilate nonfermentable carbon sources, and some cell wall integrity defects. Applying the Munich Information Centre for Protein Sequences (MIPS) functional categories revealed increased expression of genes related to ribosome biogenesis and downregulation of genes in the cell rescue, defense, cell death and aging category, suggesting a decreased response to stress conditions. A reduced level of gene expression in the unfolded protein response pathway (UPR) was observed. Cell wall genes whose expression was affected by this mutation were also identified. Several of the cAMP-responsive orphan genes, upon further investigation, revealed cell wall functions; others had previously unidentified phenotypes assigned to them. This investigation provides a statistical global transcriptome analysis of the cellular response to constitutive activation of the Ras/cAMP pathway.

Analysis of global gene expression in Brachypodium distachyon reveals extensive network plasticity in response to abiotic stress.

PubMed

Priest, Henry D; Fox, Samuel E; Rowley, Erik R; Murray, Jessica R; Michael, Todd P; Mockler, Todd C

2014-01-01

Brachypodium distachyon is a close relative of many important cereal crops. Abiotic stress tolerance has a significant impact on productivity of agriculturally important food and feedstock crops. Analysis of the transcriptome of Brachypodium after chilling, high-salinity, drought, and heat stresses revealed diverse differential expression of many transcripts. Weighted Gene Co-Expression Network Analysis revealed 22 distinct gene modules with specific profiles of expression under each stress. Promoter analysis implicated short DNA sequences directly upstream of module members in the regulation of 21 of 22 modules. Functional analysis of module members revealed enrichment in functional terms for 10 of 22 network modules. Analysis of condition-specific correlations between differentially expressed gene pairs revealed extensive plasticity in the expression relationships of gene pairs. Photosynthesis, cell cycle, and cell wall expression modules were down-regulated by all abiotic stresses. Modules which were up-regulated by each abiotic stress fell into diverse and unique gene ontology GO categories. This study provides genomics resources and improves our understanding of abiotic stress responses of Brachypodium.

Transcriptomic analysis of Crassostrea sikamea × Crassostrea angulata hybrids in response to low salinity stress.

PubMed

Yan, Lulu; Su, Jiaqi; Wang, Zhaoping; Yan, Xiwu; Yu, Ruihai; Ma, Peizhen; Li, Yangchun; Du, Junpeng

2017-01-01

Hybrid oysters often show heterosis in growth rate, weight, survival and adaptability to extremes of salinity. Oysters have also been used as model organisms to study the evolution of host-defense system. To gain comprehensive knowledge about various physiological processes in hybrid oysters under low salinity stress, we performed transcriptomic analysis of gill tissue of Crassostrea sikamea ♀ × Crassostrea angulata♂ hybrid using the deep-sequencing platform Illumina HiSeq. We exploited the high-throughput technique to delineate differentially expressed genes (DEGs) in oysters maintained in hypotonic conditions. A total of 199,391 high quality unigenes, with average length of 644 bp, were generated. Of these 35 and 31 genes showed up- and down-regulation, respectively. Functional categorization and pathway analysis of these DEGs revealed enrichment for immune mechanism, apoptosis, energy metabolism and osmoregulation under low salinity stress. The expression patterns of 41 DEGs in hybrids and their parental species were further analyzed by quantitative real-time PCR (qRT-PCR). This study will serve as a platform for subsequent gene expression analysis regarding environmental stress. Our findings will also provide valuable information about gene expression to better understand the immune mechanism, apoptosis, energy metabolism and osmoregulation in hybrid oysters under low salinity stress.

Transcriptomic analysis of Crassostrea sikamea × Crassostrea angulata hybrids in response to low salinity stress

PubMed Central

Yan, Lulu; Su, Jiaqi; Wang, Zhaoping; Yan, Xiwu; Yu, Ruihai; Ma, Peizhen; Li, Yangchun; Du, Junpeng

2017-01-01

Hybrid oysters often show heterosis in growth rate, weight, survival and adaptability to extremes of salinity. Oysters have also been used as model organisms to study the evolution of host-defense system. To gain comprehensive knowledge about various physiological processes in hybrid oysters under low salinity stress, we performed transcriptomic analysis of gill tissue of Crassostrea sikamea ♀ × Crassostrea angulata♂ hybrid using the deep-sequencing platform Illumina HiSeq. We exploited the high-throughput technique to delineate differentially expressed genes (DEGs) in oysters maintained in hypotonic conditions. A total of 199,391 high quality unigenes, with average length of 644 bp, were generated. Of these 35 and 31 genes showed up- and down-regulation, respectively. Functional categorization and pathway analysis of these DEGs revealed enrichment for immune mechanism, apoptosis, energy metabolism and osmoregulation under low salinity stress. The expression patterns of 41 DEGs in hybrids and their parental species were further analyzed by quantitative real-time PCR (qRT-PCR). This study will serve as a platform for subsequent gene expression analysis regarding environmental stress. Our findings will also provide valuable information about gene expression to better understand the immune mechanism, apoptosis, energy metabolism and osmoregulation in hybrid oysters under low salinity stress. PMID:28182701

The role of transcriptome resilience in resistance of corals to bleaching.

PubMed

Seneca, Francois O; Palumbi, Stephen R

2015-04-01

Wild populations increasingly experience extreme conditions as climate change amplifies environmental variability. How individuals respond to environmental extremes determines the impact of climate change overall. The variability of response from individual to individual can represent the opportunity for natural selection to occur as a result of extreme conditions. Here, we experimentally replicated the natural exposure to extreme temperatures of the reef lagoon at Ofu Island (American Samoa), where corals can experience severe heat stress during midday low tide. We investigated the bleaching and transcriptome response of 20 Acropora hyacinthus colonies 5 and 20 h after exposure to control (29 °C) or heated (35 °C) conditions. We found a highly dynamic transcriptome response: 27% of the coral transcriptome was significantly regulated 1 h postheat exposure. Yet 15 h later, when heat-induced coral bleaching became apparent, only 12% of the transcriptome was differentially regulated. A large proportion of responsive genes at the first time point returned to control levels, others remained differentially expressed over time, while an entirely different subset of genes was successively regulated at the second time point. However, a noteworthy variability in gene expression was observed among individual coral colonies. Among the genes of which expression lingered over time, fast return to normal levels was associated with low bleaching. Colonies that maintained higher expression levels of these genes bleached severely. Return to normal levels of gene expression after stress has been termed transcriptome resilience, and in the case of some specific genes may signal the physiological health and response ability of individuals to environmental stress. © 2015 John Wiley & Sons Ltd.

Transcriptome Analysis in Tardigrade Species Reveals Specific Molecular Pathways for Stress Adaptations

PubMed Central

Förster, Frank; Beisser, Daniela; Grohme, Markus A.; Liang, Chunguang; Mali, Brahim; Siegl, Alexander Matthias; Engelmann, Julia C.; Shkumatov, Alexander V.; Schokraie, Elham; Müller, Tobias; Schnölzer, Martina; Schill, Ralph O.; Frohme, Marcus; Dandekar, Thomas

2012-01-01

Tardigrades have unique stress-adaptations that allow them to survive extremes of cold, heat, radiation and vacuum. To study this, encoded protein clusters and pathways from an ongoing transcriptome study on the tardigrade Milnesium tardigradum were analyzed using bioinformatics tools and compared to expressed sequence tags (ESTs) from Hypsibius dujardini, revealing major pathways involved in resistance against extreme environmental conditions. ESTs are available on the Tardigrade Workbench along with software and databank updates. Our analysis reveals that RNA stability motifs for M. tardigradum are different from typical motifs known from higher animals. M. tardigradum and H. dujardini protein clusters and conserved domains imply metabolic storage pathways for glycogen, glycolipids and specific secondary metabolism as well as stress response pathways (including heat shock proteins, bmh2, and specific repair pathways). Redox-, DNA-, stress- and protein protection pathways complement specific repair capabilities to achieve the strong robustness of M. tardigradum. These pathways are partly conserved in other animals and their manipulation could boost stress adaptation even in human cells. However, the unique combination of resistance and repair pathways make tardigrades and M. tardigradum in particular so highly stress resistant. PMID:22563243

Transcriptome analysis uncovers Arabidopsis F-BOX STRESS INDUCED 1 as a regulator of jasmonic acid and abscisic acid stress gene expression.

PubMed

Gonzalez, Lauren E; Keller, Kristen; Chan, Karen X; Gessel, Megan M; Thines, Bryan C

2017-07-17

The ubiquitin 26S proteasome system (UPS) selectively degrades cellular proteins, which results in physiological changes to eukaryotic cells. F-box proteins are substrate adaptors within the UPS and are responsible for the diversity of potential protein targets. Plant genomes are enriched in F-box genes, but the vast majority of these have unknown roles. This work investigated the Arabidopsis F-box gene F-BOX STRESS INDUCED 1 (FBS1) for its effects on gene expression in order elucidate its previously unknown biological function. Using publically available Affymetrix ATH1 microarray data, we show that FBS1 is significantly co-expressed in abiotic stresses with other well-characterized stress response genes, including important stress-related transcriptional regulators. This gene suite is most highly expressed in roots under cold and salt stresses. Transcriptome analysis of fbs1-1 knock-out plants grown at a chilling temperature shows that hundreds of genes require FBS1 for appropriate expression, and that these genes are enriched in those having roles in both abiotic and biotic stress responses. Based on both this genome-wide expression data set and quantitative real-time PCR (qPCR) analysis, it is apparent that FBS1 is required for elevated expression of many jasmonic acid (JA) genes that have established roles in combatting environmental stresses, and that it also controls a subset of JA biosynthesis genes. FBS1 also significantly impacts abscisic acid (ABA) regulated genes, but this interaction is more complex, as FBS1 has both positive and negative effects on ABA-inducible and ABA-repressible gene modules. One noteworthy effect of FBS1 on ABA-related stress processes, however, is the restraint it imposes on the expression of multiple class I LIPID TRANSFER PROTEIN (LTP) gene family members that have demonstrated protective effects in water deficit-related stresses. FBS1 impacts plant stress responses by regulating hundreds of genes that respond to the plant stress hormones JA and ABA. The positive effect that FBS1 has on JA processes and the negative effect it has on at least some ABA processes indicates that it in part regulates cellular responses balanced between these two important stress hormones. More broadly then, FBS1 may aid plant cells in switching between certain biotic (JA) and abiotic (ABA) stress responses. Finally, because FBS1 regulates a subset of JA biosynthesis and response genes, we conclude that it might have a role in tuning hormone responses to particular circumstances at the transcriptional level.

De novo transcriptome sequencing of two cultivated jute species under salinity stress.

PubMed

Yang, Zemao; Yan, An; Lu, Ruike; Dai, Zhigang; Tang, Qing; Cheng, Chaohua; Xu, Ying; Su, Jianguang

2017-01-01

Soil salinity, a major environmental stress, reduces agricultural productivity by restricting plant development and growth. Jute (Corchorus spp.), a commercially important bast fiber crop, includes two commercially cultivated species, Corchorus capsularis and Corchorus olitorius. We conducted high-throughput transcriptome sequencing of 24 C. capsularis and C. olitorius samples under salt stress and found 127 common differentially expressed genes (DEGs); additionally, 4489 and 492 common DEGs were identified in the root and leaf tissues, respectively, of both Corchorus species. Further, 32, 196, and 11 common differentially expressed transcription factors (DTFs) were detected in the leaf, root, or both tissues, respectively. Several Gene Ontology (GO) terms were enriched in NY and YY. A Kyoto Encyclopedia of Genes and Genomes analysis revealed numerous DEGs in both species. Abscisic acid and cytokinin signal pathways enriched respectively about 20 DEGs in leaves and roots of both NY and YY. The Ca2+, mitogen-activated protein kinase signaling and oxidative phosphorylation pathways were also found to be related to the plant response to salt stress, as evidenced by the DEGs in the roots of both species. These results provide insight into salt stress response mechanisms in plants as well as a basis for future breeding of salt-tolerant cultivars.

Unique mechanisms of sheng yu decoction ( shèng yù tang) on ischemic stroke mice revealed by an integrated neurofunctional and transcriptome analysis.

PubMed

Hou, Yu-Chang; Lu, Chung-Kuang; Wang, Yea-Hwey; Chern, Chang-Ming; Liou, Kuo-Tong; Wang, Hsei-Wei; Shen, Yuh-Chiang

2013-10-01

Sheng Yu Decoction ( Shèng Yù Tang; SYD) is a popular traditional Chinese medicine (TCM) remedy used in treating cardiovascular and brain-related dysfunction clinically; yet, its neuroprotective mechanisms are still unclear. Here, mice were subjected to an acute ischemic stroke to examine the efficacy and mechanisms of action of SYD by an integrated neurofunctional and transcriptome analysis. More than 80% of the mice died within 2 days after ischemic stroke with vehicle treatment. Treatments with SYD (1.0 g/kg, twice daily, orally or p.o.) and recombinant thrombolytic tissue plasminogen activator (rt-PA; 10 mg/kg, once daily, intravenously or i.v.) both significantly extended the lifespan as compared to that of the vehicle-treated stroke group. SYD successfully restored brain function, ameliorated cerebral infarction and oxidative stress, and significantly improved neurological deficits in mice with stroke. Molecular impact of SYD by a genome-wide transcriptome analysis using brains from stroke mice showed a total of 162 out of 2081 ischemia-induced probe sets were significantly influenced by SYD. Mining the functional modules and genetic networks of these 162 genes revealed a significant upregulation of neuroprotective genes in Wnt receptor signaling pathway (3 genes) and regulation of cell communication (7 genes) and downregulation of destructive genes in response to stress (13 genes) and in the induction of inflammation (5 genes), cytokine production (4 genes), angiogenesis (3 genes), vasculature (6 genes) and blood vessel (5 genes) development, wound healing (7 genes), defense response (7 genes), chemotaxis (4 genes), immune response (7 genes), antigen processing and presenting (3 genes), and leukocyte-mediated cytotoxicity (2 genes) by SYD. Our results suggest that SYD could protect mice against ischemic stroke primarily through significantly downregulating the damaging genes involved in stress, inflammation, angiogenesis, blood vessel formation, immune responses, and wound healing, as well as upregulating the genes mediating neurogenesis and cell communication, which make SYD beneficial for treating ischemic stroke.

Transcriptome Analysis of H2O2-Treated Wheat Seedlings Reveals a H2O2-Responsive Fatty Acid Desaturase Gene Participating in Powdery Mildew Resistance

PubMed Central

Tang, Lichuan; Zhao, Guangyao; Zhu, Mingzhu; Chu, Jinfang; Sun, Xiaohong; Wei, Bo; Zhang, Xiangqi; Jia, Jizeng; Mao, Long

2011-01-01

Hydrogen peroxide (H2O2) plays important roles in plant biotic and abiotic stress responses. However, the effect of H2O2 stress on the bread wheat transcriptome is still lacking. To investigate the cellular and metabolic responses triggered by H2O2, we performed an mRNA tag analysis of wheat seedlings under 10 mM H2O2 treatment for 6 hour in one powdery mildew (PM) resistant (PmA) and two susceptible (Cha and Han) lines. In total, 6,156, 6,875 and 3,276 transcripts were found to be differentially expressed in PmA, Han and Cha respectively. Among them, 260 genes exhibited consistent expression patterns in all three wheat lines and may represent a subset of basal H2O2 responsive genes that were associated with cell defense, signal transduction, photosynthesis, carbohydrate metabolism, lipid metabolism, redox homeostasis, and transport. Among genes specific to PmA, ‘transport’ activity was significantly enriched in Gene Ontology analysis. MapMan classification showed that, while both up- and down- regulations were observed for auxin, abscisic acid, and brassinolides signaling genes, the jasmonic acid and ethylene signaling pathway genes were all up-regulated, suggesting H2O2-enhanced JA/Et functions in PmA. To further study whether any of these genes were involved in wheat PM response, 19 H2O2-responsive putative defense related genes were assayed in wheat seedlings infected with Blumeria graminis f. sp. tritici (Bgt). Eight of these genes were found to be co-regulated by H2O2 and Bgt, among which a fatty acid desaturase gene TaFAD was then confirmed by virus induced gene silencing (VIGS) to be required for the PM resistance. Together, our data presents the first global picture of the wheat transcriptome under H2O2 stress and uncovers potential links between H2O2 and Bgt responses, hence providing important candidate genes for the PM resistance in wheat. PMID:22174904

Clostridium thermocellum Transcriptomic Profiles after Exposure to Furfural or Heat Stress

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilson, Charlotte M; Yang, Shihui; Rodriguez, Jr., Miguel

2013-01-01

Background The thermophilic anaerobe Clostridium thermocellum is a candidate consolidated bioprocessing (CBP)biocatalyst for cellulosic ethanol production. It is capable of both cellulose solubilization and its fermentation to produce lignocellulosic ethanol. Intolerance to stresses routinely encountered during industrial fermentations may hinder the commercial development of this organism. A previous C. thermocellum ethanol stress study showed that largest transcriptomic response was in genes and proteins related to nitrogen uptake and metabolism. Results In this study, C. thermocellum was grown to mid-exponential phase and treated with furfural or heat to a final concentration of 3 g.L-1 or 68 C respectively to investigate generalmore » and specific physiological and regulatory stress responses. Samples were taken at 10, 30, 60 and 120 min post-shock, and from untreated control fermentations, for transcriptomic analyses and fermentation product determinations and compared to a published dataset from an ethanol stress study. Urea uptake genes were induced following furfural stress, but not to the same extent as ethanol stress and transcription from these genes was largely unaffected by heat stress. The largest transcriptomic response to furfural stress was genes for sulfate transporter subunits and enzymes in the sulfate assimilatory pathway, although these genes were also affected late in the heat and ethanol stress responses. Lactate production was higher in furfural treated culture, although the lactate dehydrogenase gene was not differentially expressed under this condition. Other redox related genes such as a copy of the rex gene, a bifunctional acetaldehyde-CoA/alcohol dehydrogenase and adjacent genes did show lower expression after furfural stress compared to the control, heat and ethanol fermentation profiles. Heat stress induced expression from chaperone related genes and overlap was observed with the responses to the other stresses. This study suggests the involvement of C. thermocellum genes with functions in oxidative stress protection, electron transfer, detoxification, sulfur and nitrogen acquisition, and DNA repair mechanisms in its stress responses and the use of different regulatory networks to coordinate and control adaptation. Conclusions This study has identified C. thermocellum gene regulatory motifs and aspects of physiology and gene regulation for further study. The nexus between future systems biology studies and recently developed genetic tools for C. thermocellum offers the potential for more rapid strain development and for broader insights into this organism s physiology and regulation.« less

De Novo Assembly and Analysis of Tartary Buckwheat (Fagopyrum tataricum Garetn.) Transcriptome Discloses Key Regulators Involved in Salt-Stress Response

PubMed Central

Wu, Qi; Bai, Xue; Zhao, Wei; Xiang, Dabing; Wan, Yan; Yan, Jun; Zou, Liang; Zhao, Gang

2017-01-01

Soil salinization has been a tremendous obstacle for agriculture production. The regulatory networks underlying salinity adaption in model plants have been extensively explored. However, limited understanding of the salt response mechanisms has hindered the planting and production in Fagopyrum tataricum, an economic and health-beneficial plant mainly distributing in southwest China. In this study, we performed physiological analysis and found that salt stress of 200 mM NaCl solution significantly affected the relative water content (RWC), electrolyte leakage (EL), malondialdehyde (MDA) content, peroxidase (POD) and superoxide dismutase (SOD) activities in tartary buckwheat seedlings. Further, we conducted transcriptome comparison between control and salt treatment to identify potential regulatory components involved in F. tataricum salt responses. A total of 53.15 million clean reads from control and salt-treated libraries were produced via an Illumina sequencing approach. Then we de novo assembled these reads into a transcriptome dataset containing 57,921 unigenes with N50 length of 1400 bp and total length of 44.5 Mb. A total of 36,688 unigenes could find matches in public databases. GO, KEGG and KOG classification suggested the enrichment of these unigenes in 56 sub-categories, 25 KOG, and 273 pathways, respectively. Comparison of the transcriptome expression patterns between control and salt treatment unveiled 455 differentially expressed genes (DEGs). Further, we found the genes encoding for protein kinases, phosphatases, heat shock proteins (HSPs), ATP-binding cassette (ABC) transporters, glutathione S-transferases (GSTs), abiotic-related transcription factors and circadian clock might be relevant to the salinity adaption of this species. Thus, this study offers an insight into salt tolerance mechanisms, and will serve as useful genetic information for tolerant elite breeding programs in future. PMID:28972562

Mediterranean versus Red sea corals facing climate change, a transcriptome analysis

NASA Astrophysics Data System (ADS)

Maor-Landaw, Keren; Waldman Ben-Asher, Hiba; Karako-Lampert, Sarit; Salmon-Divon, Mali; Prada, Fiorella; Caroselli, Erik; Goffredo, Stefano; Falini, Giuseppe; Dubinsky, Zvy; Levy, Oren

2017-02-01

The anthropogenic increase in atmospheric CO2 that drives global warming and ocean acidification raises serious concerns regarding the future of corals, the main carbonate biomineralizers. Here we used transcriptome analysis to study the effect of long-term gradual temperature increase (annual rate), combined with lowered pH values, on a sub-tropical Red Sea coral, Stylophora pistillata, and on a temperate Mediterranean symbiotic coral Balanophyllia europaea. The gene expression profiles revealed a strong effect of both temperature increase and pH decrease implying for synergism response. The temperate coral, exposed to a twice as high range of seasonal temperature fluctuations than the Red Sea species, faced stress more effectively. The compensatory strategy for coping apparently involves deviating cellular resources into a massive up-regulation of genes in general, and specifically of genes involved in the generation of metabolic energy. Our results imply that sub-lethal, prolonged exposure to stress can stimulate evolutionary increase in stress resilience.

Comparative functional genomics of salt stress in related model and cultivated plants identifies and overcomes limitations to translational genomics.

PubMed

Sanchez, Diego H; Pieckenstain, Fernando L; Szymanski, Jedrzey; Erban, Alexander; Bromke, Mariusz; Hannah, Matthew A; Kraemer, Ute; Kopka, Joachim; Udvardi, Michael K

2011-02-14

One of the objectives of plant translational genomics is to use knowledge and genes discovered in model species to improve crops. However, the value of translational genomics to plant breeding, especially for complex traits like abiotic stress tolerance, remains uncertain. Using comparative genomics (ionomics, transcriptomics and metabolomics) we analyzed the responses to salinity of three model and three cultivated species of the legume genus Lotus. At physiological and ionomic levels, models responded to salinity in a similar way to crop species, and changes in the concentration of shoot Cl(-) correlated well with tolerance. Metabolic changes were partially conserved, but divergence was observed amongst the genotypes. Transcriptome analysis showed that about 60% of expressed genes were responsive to salt treatment in one or more species, but less than 1% was responsive in all. Therefore, genotype-specific transcriptional and metabolic changes overshadowed conserved responses to salinity and represent an impediment to simple translational genomics. However, 'triangulation' from multiple genotypes enabled the identification of conserved and tolerant-specific responses that may provide durable tolerance across species.

Response of microRNAs to cold treatment in the young spikes of common wheat.

PubMed

Song, Guoqi; Zhang, Rongzhi; Zhang, Shujuan; Li, Yulian; Gao, Jie; Han, Xiaodong; Chen, Mingli; Wang, Jiao; Li, Wei; Li, Genying

2017-02-28

MicroRNAs (miRNAs) are a class of small non-coding RNAs that play important roles in biotic and abiotic stresses by regulating their target genes. For common wheat, spring frost damage frequently occurs, especially when low temperature coincides with plants at early floral organ differentiation, which may result in significant yield loss. Up to date, the role of miRNAs in wheat response to frost stress is not well understood. We report here the sequencing of small RNA transcriptomes from the young spikes that were treated with cold stress and the comparative analysis with those of the control. A total of 192 conserved miRNAs from 105 families and nine novel miRNAs were identified. Among them, 34 conserved and five novel miRNAs were differentially expressed between the cold-stressed samples and the controls. The expression patterns of 18 miRNAs were further validated by quantitative real time polymerase chain reaction (qRT-PCR). Moreover, nearly half of the miRNAs were cross inducible by biotic and abiotic stresses when compared with previously published work. Target genes were predicted and validated by degradome sequencing. Gene Ontology (GO) enrichment analysis showed that the target genes of differentially expressed miRNAs were enriched for response to the stimulus, regulation of transcription, and ion transport functions. Since many targets of differentially expressed miRNAs were transcription factors that are associated with floral development such as ARF, SPB (Squamosa Promoter Binding like protein), MADS-box (MCM1, AG, DEFA and SRF), MYB, SPX (SYG1, Pho81 and XPR1), TCP (TEOSINTE BRANCHED, Cycloidea and PCF), and PPR (PentatricoPeptide Repeat) genes, cold-altered miRNA expression may cause abnormal reproductive organ development. Analysis of small RNA transcriptomes and their target genes provide new insight into miRNA regulation in developing wheat inflorescences under cold stress. MiRNAs provide another layer of gene regulation in cold stress response that can be genetically manipulated to reduce yield loss in wheat.

Identification of Rice Genes Associated With Enhanced Cold Tolerance by Comparative Transcriptome Analysis With Two Transgenic Rice Plants Overexpressing DaCBF4 or DaCBF7, Isolated From Antarctic Flowering Plant Deschampsia antarctica

PubMed Central

Byun, Mi Young; Cui, Li Hua; Lee, Jungeun; Park, Hyun; Lee, Andosung; Kim, Woo Taek; Lee, Hyoungseok

2018-01-01

Few plant species can survive in Antarctica, the harshest environment for living organisms. Deschampsia antarctica is the only natural grass species to have adapted to and colonized the maritime Antarctic. To investigate the molecular mechanism of the Antarctic adaptation of this plant, we identified and characterized D. antarctica C-repeat binding factor 4 (DaCBF4), which belongs to monocot CBF group IV. The transcript level of DaCBF4 in D. antarctica was markedly increased by cold and dehydration stress. To assess the roles of DaCBF4 in plants, we generated a DaCBF4-overexpressing transgenic rice plant (Ubi:DaCBF4) and analyzed its abiotic stress response phenotype. Ubi:DaCBF4 displayed enhanced tolerance to cold stress without growth retardation under any condition compared to wild-type plants. Because the cold-specific phenotype of Ubi:DaCBF4 was similar to that of Ubi:DaCBF7 (Byun et al., 2015), we screened for the genes responsible for the improved cold tolerance in rice by selecting differentially regulated genes in both transgenic rice lines. By comparative transcriptome analysis using RNA-seq, we identified 9 and 15 genes under normal and cold-stress conditions, respectively, as putative downstream targets of the two D. antarctica CBFs. Overall, our results suggest that Antarctic hairgrass DaCBF4 mediates the cold-stress response of transgenic rice plants by adjusting the expression levels of a set of stress-responsive genes in transgenic rice plants. Moreover, selected downstream target genes will be useful for genetic engineering to enhance the cold tolerance of cereal plants, including rice. PMID:29774046

Identification of Rice Genes Associated With Enhanced Cold Tolerance by Comparative Transcriptome Analysis With Two Transgenic Rice Plants Overexpressing DaCBF4 or DaCBF7, Isolated From Antarctic Flowering Plant Deschampsia antarctica.

PubMed

Byun, Mi Young; Cui, Li Hua; Lee, Jungeun; Park, Hyun; Lee, Andosung; Kim, Woo Taek; Lee, Hyoungseok

2018-01-01

Few plant species can survive in Antarctica, the harshest environment for living organisms. Deschampsia antarctica is the only natural grass species to have adapted to and colonized the maritime Antarctic. To investigate the molecular mechanism of the Antarctic adaptation of this plant, we identified and characterized D. antarctica C-repeat binding factor 4 ( DaCBF4 ), which belongs to monocot CBF group IV. The transcript level of DaCBF4 in D. antarctica was markedly increased by cold and dehydration stress. To assess the roles of DaCBF4 in plants, we generated a DaCBF4 -overexpressing transgenic rice plant ( Ubi:DaCBF4 ) and analyzed its abiotic stress response phenotype. Ubi:DaCBF4 displayed enhanced tolerance to cold stress without growth retardation under any condition compared to wild-type plants. Because the cold-specific phenotype of Ubi:DaCBF4 was similar to that of Ubi:DaCBF7 (Byun et al., 2015), we screened for the genes responsible for the improved cold tolerance in rice by selecting differentially regulated genes in both transgenic rice lines. By comparative transcriptome analysis using RNA-seq, we identified 9 and 15 genes under normal and cold-stress conditions, respectively, as putative downstream targets of the two D. antarctica CBFs. Overall, our results suggest that Antarctic hairgrass DaCBF4 mediates the cold-stress response of transgenic rice plants by adjusting the expression levels of a set of stress-responsive genes in transgenic rice plants. Moreover, selected downstream target genes will be useful for genetic engineering to enhance the cold tolerance of cereal plants, including rice.

Patterns of gene expression associated with recovery and injury in heat-stressed rats.

PubMed

Stallings, Jonathan D; Ippolito, Danielle L; Rakesh, Vineet; Baer, Christine E; Dennis, William E; Helwig, Bryan G; Jackson, David A; Leon, Lisa R; Lewis, John A; Reifman, Jaques

2014-12-03

The in vivo gene response associated with hyperthermia is poorly understood. Here, we perform a global, multiorgan characterization of the gene response to heat stress using an in vivo conscious rat model. We heated rats until implanted thermal probes indicated a maximal core temperature of 41.8°C (Tc,Max). We then compared transcriptomic profiles of liver, lung, kidney, and heart tissues harvested from groups of experimental animals at Tc,Max, 24 hours, and 48 hours after heat stress to time-matched controls kept at an ambient temperature. Cardiac histopathology at 48 hours supported persistent cardiac injury in three out of six animals. Microarray analysis identified 78 differentially expressed genes common to all four organs at Tc,Max. Self-organizing maps identified gene-specific signatures corresponding to protein-folding disorders in heat-stressed rats with histopathological evidence of cardiac injury at 48 hours. Quantitative proteomics analysis by iTRAQ (isobaric tag for relative and absolute quantitation) demonstrated that differential protein expression most closely matched the transcriptomic profile in heat-injured animals at 48 hours. Calculation of protein supersaturation scores supported an increased propensity of proteins to aggregate for proteins that were found to be changing in abundance at 24 hours and in animals with cardiac injury at 48 hours, suggesting a mechanistic association between protein misfolding and the heat-stress response. Pathway analyses at both the transcript and protein levels supported catastrophic deficits in energetics and cellular metabolism and activation of the unfolded protein response in heat-stressed rats with histopathological evidence of persistent heat injury, providing the basis for a systems-level physiological model of heat illness and recovery.

Leaf Responses to Mild Drought Stress in Natural Variants of Arabidopsis1[OPEN

PubMed Central

Clauw, Pieter; Coppens, Frederik; De Beuf, Kristof; Dhondt, Stijn; Van Daele, Twiggy; Maleux, Katrien; Storme, Veronique; Clement, Lieven; Gonzalez, Nathalie; Inzé, Dirk

2015-01-01

Although the response of plants exposed to severe drought stress has been studied extensively, little is known about how plants adapt their growth under mild drought stress conditions. Here, we analyzed the leaf and rosette growth response of six Arabidopsis (Arabidopsis thaliana) accessions originating from different geographic regions when exposed to mild drought stress. The automated phenotyping platform WIWAM was used to impose stress early during leaf development, when the third leaf emerges from the shoot apical meristem. Analysis of growth-related phenotypes showed differences in leaf development between the accessions. In all six accessions, mild drought stress reduced both leaf pavement cell area and number without affecting the stomatal index. Genome-wide transcriptome analysis (using RNA sequencing) of early developing leaf tissue identified 354 genes differentially expressed under mild drought stress in the six accessions. Our results indicate the existence of a robust response over different genetic backgrounds to mild drought stress in developing leaves. The processes involved in the overall mild drought stress response comprised abscisic acid signaling, proline metabolism, and cell wall adjustments. In addition to these known severe drought-related responses, 87 genes were found to be specific for the response of young developing leaves to mild drought stress. PMID:25604532

The Transcriptome of the Zebrafish Embryo After Chemical Exposure: A Meta-Analysis.

PubMed

Schüttler, Andreas; Reiche, Kristin; Altenburger, Rolf; Busch, Wibke

2017-06-01

Numerous studies have been published in the past years investigating the transcriptome of the zebrafish embryo (ZFE) upon being subjected to chemical stress. Aiming at a more mechanistic understanding of the results of such studies, knowledge about commonalities of transcript regulation in response to chemical stress is needed. Thus, our goal in this study was to identify and interpret genes and gene sets constituting a general response to chemical exposure. Therefore, we aggregated and reanalyzed published toxicogenomics data obtained with the ZFE. We found that overlap of differentially transcribed genes in response to chemical stress across independent studies is generally low and the most commonly differentially transcribed genes appear in less than 50% of all treatments across studies. However, effect size analysis revealed several genes showing a common trend of differential expression, among which genes related to calcium homeostasis emerged as key, especially in exposure settings up to 24 h post-fertilization. Additionally, we found that these and other downregulated genes are often linked to anatomical regions developing during the respective exposure period. Genes showing a trend of increased expression were, among others, linked to signaling pathways (e.g., Wnt, Fgf) as well as lysosomal structures and apoptosis. The findings of this study help to increase the understanding of chemical stress responses in the developing zebrafish embryo and provide a starting point to improve experimental designs for this model system. In future, improved time- and concentration-resolved experiments should offer better understanding of stress response patterns and access to mechanistic information. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology.

Comparative transcriptome analysis of the Asteraceae halophyte Karelinia caspica under salt stress.

PubMed

Zhang, Xia; Liao, Maoseng; Chang, Dan; Zhang, Fuchun

2014-12-17

Much attention has been given to the potential of halophytes as sources of tolerance traits for introduction into cereals. However, a great deal remains unknown about the diverse mechanisms employed by halophytes to cope with salinity. To characterize salt tolerance mechanisms underlying Karelinia caspica, an Asteraceae halophyte, we performed Large-scale transcriptomic analysis using a high-throughput Illumina sequencing platform. Comparative gene expression analysis was performed to correlate the effects of salt stress and ABA regulation at the molecular level. Total sequence reads generated by pyrosequencing were assembled into 287,185 non-redundant transcripts with an average length of 652 bp. Using the BLAST function in the Swiss-Prot, NCBI nr, GO, KEGG, and KOG databases, a total of 216,416 coding sequences associated with known proteins were annotated. Among these, 35,533 unigenes were classified into 69 gene ontology categories, and 18,378 unigenes were classified into 202 known pathways. Based on the fold changes observed when comparing the salt stress and control samples, 60,127 unigenes were differentially expressed, with 38,122 and 22,005 up- and down-regulated, respectively. Several of the differentially expressed genes are known to be involved in the signaling pathway of the plant hormone ABA, including ABA metabolism, transport, and sensing as well as the ABA signaling cascade. Transcriptome profiling of K. caspica contribute to a comprehensive understanding of K. caspica at the molecular level. Moreover, the global survey of differentially expressed genes in this species under salt stress and analyses of the effects of salt stress and ABA regulation will contribute to the identification and characterization of genes and molecular mechanisms underlying salt stress responses in Asteraceae plants.

Transcriptome sequencing of rhizome tissue of Sinopodophyllum hexandrum at two temperatures.

PubMed

Kumari, Anita; Singh, Heikham Russiachand; Jha, Ashwani; Swarnkar, Mohit Kumar; Shankar, Ravi; Kumar, Sanjay

2014-10-07

Sinopodophyllum hexandrum is an endangered medicinal herb, which is commonly present in elevations ranging between 2,400-4,500 m and is sensitive to temperature. Medicinal property of the species is attributed to the presence of podophyllotoxin in the rhizome tissue. The present work analyzed transcriptome of rhizome tissue of S. hexandrum exposed to 15°C and 25°C to understand the temperature mediated molecular responses including those associated with podophyllotoxin biosynthesis. Deep sequencing of transcriptome with an average coverage of 88.34X yielded 60,089 assembled transcript sequences representing 20,387 unique genes having homology to known genes. Fragments per kilobase of exon per million fragments mapped (FPKM) based expression analysis revealed genes related to growth and development were over-expressed at 15°C, whereas genes involved in stress response were over-expressed at 25°C. There was a decreasing trend of podophyllotoxin accumulation at 25°C; data was well supported by the expression of corresponding genes of the pathway. FPKM data was validated by quantitative real-time polymerase chain reaction data using a total of thirty four genes and a positive correlation between the two platforms of gene expression was obtained. Also, detailed analyses yielded cytochrome P450s, methyltransferases and glycosyltransferases which could be the potential candidate hitherto unidentified genes of podophyllotoxin biosynthesis pathway. The present work revealed temperature responsive transcriptome of S. hexandrum on Illumina platform. Data suggested expression of genes for growth and development and podophyllotoxin biosynthesis at 15°C, and prevalence of those associated with stress response at 25°C.

Comparative Immune- and Stress-Related Transcript Response Induced by Air Exposure and Vibrio anguillarum Bacterin in Rainbow Trout (Oncorhynchus mykiss) and Gilthead Seabream (Sparus aurata) Mucosal Surfaces

PubMed Central

Khansari, Ali Reza; Balasch, Joan Carles; Vallejos-Vidal, Eva; Parra, David; Reyes-López, Felipe E.; Tort, Lluís

2018-01-01

Fish have to face various environmental challenges that may compromise the efficacy of the immune response in mucosal surfaces. Since the effect of acute stress on mucosal barriers in fish has still not been fully elucidated, we aimed to compare the short-term mucosal stress and immune transcriptomic responses in a freshwater (rainbow trout, Oncorhynchus mykiss) and a marine fish (gilthead seabream, Sparus aurata) to bacterial immersion (Vibrio anguillarum bacterin vaccine) and air exposure stress in skin, gills, and intestine. Air exposure and combined (vaccine + air) stressors exposure were found to be inducers of the cortisol secretion in plasma and skin mucus on both species in a time-dependent manner, while V. anguillarum bacterin exposure induced cortisol release in trout skin mucus only. This was coincident with a marked differential increase in transcriptomic patterns of stress- and immune-related gene expression profiles. Particularly in seabream skin, the expression of cytokines was markedly enhanced, whereas in gills the response was mainly suppressed. In rainbow trout gut, both air exposure and vaccine stimulated the transcriptomic response, whereas in seabream, stress and immune responses were mainly induced by air exposure. Therefore, our comparative survey on the transcriptomic mucosal responses demonstrates that skin and gut were generally more reactive in both species. However, the upregulation of immune transcripts was more pronounced in gills and gut of vaccinated trout, whereas seabream appeared to be more stress-prone and less responsive to V. anguillarum bacterin in gills and gut. When fish were subjected to both treatments no definite pattern was observed. Overall, the results indicate that (1) the immune response was not homogeneous among mucosae (2), it was greatly influenced by the specific traits of each stressor in each surface and (3) was highly species-specific, probably as a result of the adaptive life story of each species to the microbial load and environmental characteristics of their respective natural habitats. PMID:29770134

Transcriptome responses to heat- and cold-stress in ladybirds (Cryptolaemus montrouzieri Mulasnt) analyzed by deep-sequencing.

PubMed

Zhang, Yuhong; Wu, Hongsheng; Xie, Jiaqin; Jiang, Ruixin; Deng, Congshuang; Pang, Hong

2015-11-19

Changed temperature not only threaten agricultural production, but they also affect individual biological behavior, population and community of many insects, and consequently reduce the stability of our ecosystem. Insect's ability to respond to temperature stress evolved through a complex adaptive process, thus resulting in varied temperature tolerance among different insects. Both high and low extreme temperatures are detrimental to insect development since they constitute an important abiotic stress capable of inducing abnormal biological responses. Many studies on heat or cold tolerance of ladybirds have focused on measurements of physiological and biochemical indexes such as supercooling point, higher/lower lethal temperatures, survival rate, dry body weight, water content, and developmental duration. And studies of the molecular mechanisms of ladybird responses to heat or cold stress have focused on single genes, such as those encoding heat shock proteins, but has not been analyzed by transcriptome profiling. In this study, we report the use of Digital Gene Expression (DGE) tag profiling to gain insight into transcriptional events associated with heat- and cold-stress in C. montrouzieri. About 6 million tags (49 bp in length) were sequenced in a heat stress group, a cold stress group and a negative control group. We obtained 687 and 573 genes that showed significantly altered expression levels following heat and cold shock treatments, respectively. Analysis of the global gene expression pattern suggested that 42 enzyme-encoding genes mapped to many Gene Ontology terms are associated with insect's response to heat- and cold-stress. These results provide a global assessment of genes and molecular mechanisms involved in heat and cold tolerance.

Genome-Wide Transcriptome Analysis Reveals Conserved and Distinct Molecular Mechanisms of Al Resistance in Buckwheat (Fagopyrum esculentum Moench) Leaves

PubMed Central

Chen, Wei Wei; Xu, Jia Meng; Jin, Jian Feng; Lou, He Qiang; Fan, Wei

2017-01-01

Being an Al-accumulating crop, buckwheat detoxifies and tolerates Al not only in roots but also in leaves. While much progress has recently been made toward Al toxicity and resistance mechanisms in roots, little is known about the molecular basis responsible for detoxification and tolerance processes in leaves. Here, we carried out transcriptome analysis of buckwheat leaves in response to Al stress (20 µM, 24 h). We obtained 33,931 unigenes with 26,300 unigenes annotated in the NCBI database, and identified 1063 upregulated and 944 downregulated genes under Al stress. Functional category analysis revealed that genes related to protein translation, processing, degradation and metabolism comprised the biological processes most affected by Al, suggesting that buckwheat leaves maintain flexibility under Al stress by rapidly reprogramming their physiology and metabolism. Analysis of genes related to transcription regulation revealed that a large proportion of chromatin-regulation genes are specifically downregulated by Al stress, whereas transcription factor genes are overwhelmingly upregulated. Furthermore, we identified 78 upregulated and 22 downregulated genes that encode transporters. Intriguingly, only a few genes were overlapped with root Al-regulated transporter genes, which include homologs of AtMATE, ALS1, STAR1, ALS3 and a divalent ion symporter. In addition, we identified a subset of genes involved in development, in which genes associated with flowering regulation were important. Based on these data, it is proposed that buckwheat leaves develop conserved and distinct mechanisms to cope with Al toxicity. PMID:28846612

Genome-Wide Transcriptome Analysis Reveals Conserved and Distinct Molecular Mechanisms of Al Resistance in Buckwheat (Fagopyrum esculentum Moench) Leaves.

PubMed

Chen, Wei Wei; Xu, Jia Meng; Jin, Jian Feng; Lou, He Qiang; Fan, Wei; Yang, Jian Li

2017-08-27

Being an Al-accumulating crop, buckwheat detoxifies and tolerates Al not only in roots but also in leaves. While much progress has recently been made toward Al toxicity and resistance mechanisms in roots, little is known about the molecular basis responsible for detoxification and tolerance processes in leaves. Here, we carried out transcriptome analysis of buckwheat leaves in response to Al stress (20 µM, 24 h). We obtained 33,931 unigenes with 26,300 unigenes annotated in the NCBI database, and identified 1063 upregulated and 944 downregulated genes under Al stress. Functional category analysis revealed that genes related to protein translation, processing, degradation and metabolism comprised the biological processes most affected by Al, suggesting that buckwheat leaves maintain flexibility under Al stress by rapidly reprogramming their physiology and metabolism. Analysis of genes related to transcription regulation revealed that a large proportion of chromatin-regulation genes are specifically downregulated by Al stress, whereas transcription factor genes are overwhelmingly upregulated. Furthermore, we identified 78 upregulated and 22 downregulated genes that encode transporters. Intriguingly, only a few genes were overlapped with root Al-regulated transporter genes, which include homologs of AtMATE , ALS1 , STAR1 , ALS3 and a divalent ion symporter. In addition, we identified a subset of genes involved in development, in which genes associated with flowering regulation were important. Based on these data, it is proposed that buckwheat leaves develop conserved and distinct mechanisms to cope with Al toxicity.

Transcriptome Analysis of Early Responsive Genes in Rice during Magnaporthe oryzae Infection.

PubMed

Wang, Yiming; Kwon, Soon Jae; Wu, Jingni; Choi, Jaeyoung; Lee, Yong-Hwan; Agrawal, Ganesh Kumar; Tamogami, Shigeru; Rakwal, Randeep; Park, Sang-Ryeol; Kim, Beom-Gi; Jung, Ki-Hong; Kang, Kyu Young; Kim, Sang Gon; Kim, Sun Tae

2014-12-01

Rice blast disease caused by Magnaporthe oryzae is one of the most serious diseases of cultivated rice (Oryza sativa L.) in most rice-growing regions of the world. In order to investigate early response genes in rice, we utilized the transcriptome analysis approach using a 300 K tilling microarray to rice leaves infected with compatible and incompatible M. oryzae strains. Prior to the microarray experiment, total RNA was validated by measuring the differential expression of rice defense-related marker genes (chitinase 2, barwin, PBZ1, and PR-10) by RT-PCR, and phytoalexins (sakuranetin and momilactone A) with HPLC. Microarray analysis revealed that 231 genes were up-regulated (>2 fold change, p < 0.05) in the incompatible interaction compared to the compatible one. Highly expressed genes were functionally characterized into metabolic processes and oxidation-reduction categories. The oxidative stress response was induced in both early and later infection stages. Biotic stress overview from MapMan analysis revealed that the phytohormone ethylene as well as signaling molecules jasmonic acid and salicylic acid is important for defense gene regulation. WRKY and Myb transcription factors were also involved in signal transduction processes. Additionally, receptor-like kinases were more likely associated with the defense response, and their expression patterns were validated by RT-PCR. Our results suggest that candidate genes, including receptor-like protein kinases, may play a key role in disease resistance against M. oryzae attack.

A comparison of the transcriptome of Drosophila melanogaster in response to entomopathogenic fungus, ionizing radiation, starvation and cold shock.

PubMed

Moskalev, Alexey; Zhikrivetskaya, Svetlana; Krasnov, George; Shaposhnikov, Mikhail; Proshkina, Ekaterina; Borisoglebsky, Dmitry; Danilov, Anton; Peregudova, Darya; Sharapova, Irina; Dobrovolskaya, Eugenia; Solovev, Ilya; Zemskaya, Nadezhda; Shilova, Lyubov; Snezhkina, Anastasia; Kudryavtseva, Anna

2015-01-01

The molecular mechanisms that determine the organism's response to a variety of doses and modalities of stress factors are not well understood. We studied effects of ionizing radiation (144, 360 and 864 Gy), entomopathogenic fungus (10 and 100 CFU), starvation (16 h), and cold shock (+4, 0 and -4°C) on an organism's viability indicators (survival and locomotor activity) and transcriptome changes in the Drosophila melanogaster model. All stress factors but cold shock resulted in a decrease of lifespan proportional to the dose of treatment. However, stress-factors affected locomotor activity without correlation with lifespan. Our data revealed both significant similarities and differences in differential gene expression and the activity of biological processes under the influence of stress factors. Studied doses of stress treatments deleteriously affect the organism's viability and lead to different changes of both general and specific cellular stress response mechanisms.

Global Analysis of Salmonella Alternative Sigma Factor E on Protein Translation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Jie; Nakayasu, Ernesto S.; Overall, Christopher C.

The alternative sigma factor E (σ E) is critical for response to extracytoplasmic stress in Salmonella. Extensive studies have been conducted on σ E-regulated gene expression, particularly at the transcriptional level. Increasing evidence suggests however that σ E may indirectly participate in post-transcriptional regulation. Here in this study, we conducted sample-matched global proteomic and transcriptomic analyses to determine the level of regulation mediated by σ E in Salmonella. We analysed samples from wild type and isogenic rpoE mutant Salmonella cultivated in three different conditions; nutrient-rich and conditions that mimic early and late intracellular infection. We found that 30% of themore » observed proteome was regulated by σ E combining all three conditions. In different growth conditions, σ E affected the expression of a broad spectrum of Salmonella proteins required for miscellaneous functions. Those involved in transport and binding, protein synthesis, and stress response were particularly highlighted. By comparing transcriptomic and proteomic data, we identified genes post-transcriptionally regulated by σ E and found that post-transcriptional regulation was responsible for a majority of changes observed in the σ E-regulated proteome. Further, comparison of transcriptomic and proteomic data from hfq mutant of Salmonella demonstrated that σ E–mediated post-transcriptional regulation was partially dependent on the RNA-binding protein Hfq.« less

Global Analysis of Salmonella Alternative Sigma Factor E on Protein Translation

DOE PAGES

Li, Jie; Nakayasu, Ernesto S.; Overall, Christopher C.; ...

2015-02-16

The alternative sigma factor E (σ E) is critical for response to extracytoplasmic stress in Salmonella. Extensive studies have been conducted on σ E-regulated gene expression, particularly at the transcriptional level. Increasing evidence suggests however that σ E may indirectly participate in post-transcriptional regulation. Here in this study, we conducted sample-matched global proteomic and transcriptomic analyses to determine the level of regulation mediated by σ E in Salmonella. We analysed samples from wild type and isogenic rpoE mutant Salmonella cultivated in three different conditions; nutrient-rich and conditions that mimic early and late intracellular infection. We found that 30% of themore » observed proteome was regulated by σ E combining all three conditions. In different growth conditions, σ E affected the expression of a broad spectrum of Salmonella proteins required for miscellaneous functions. Those involved in transport and binding, protein synthesis, and stress response were particularly highlighted. By comparing transcriptomic and proteomic data, we identified genes post-transcriptionally regulated by σ E and found that post-transcriptional regulation was responsible for a majority of changes observed in the σ E-regulated proteome. Further, comparison of transcriptomic and proteomic data from hfq mutant of Salmonella demonstrated that σ E–mediated post-transcriptional regulation was partially dependent on the RNA-binding protein Hfq.« less

Comparative Transcriptome Analysis Reveals Different Molecular Mechanisms of Bacillus coagulans 2-6 Response to Sodium Lactate and Calcium Lactate during Lactic Acid Production

PubMed Central

Qin, Jiayang; Wang, Xiuwen; Wang, Landong; Zhu, Beibei; Zhang, Xiaohua; Yao, Qingshou; Xu, Ping

2015-01-01

Lactate production is enhanced by adding calcium carbonate or sodium hydroxide during fermentation. However, Bacillus coagulans 2-6 can produce more than 180 g/L L-lactic acid when calcium lactate is accumulated, but less than 120 g/L L-lactic acid when sodium lactate is formed. The molecular mechanisms by which B. coagulans responds to calcium lactate and sodium lactate remain unclear. In this study, comparative transcriptomic methods based on high-throughput RNA sequencing were applied to study gene expression changes in B. coagulans 2-6 cultured in non-stress, sodium lactate stress and calcium lactate stress conditions. Gene expression profiling identified 712 and 1213 significantly regulated genes in response to calcium lactate stress and sodium lactate stress, respectively. Gene ontology assignments of the differentially expressed genes were performed. KEGG pathway enrichment analysis revealed that ‘ATP-binding cassette transporters’ were significantly affected by calcium lactate stress, and ‘amino sugar and nucleotide sugar metabolism’ was significantly affected by sodium lactate stress. It was also found that lactate fermentation was less affected by calcium lactate stress than by sodium lactate stress. Sodium lactate stress had negative effect on the expression of ‘glycolysis/gluconeogenesis’ genes but positive effect on the expression of ‘citrate cycle (TCA cycle)’ genes. However, calcium lactate stress had positive influence on the expression of ‘glycolysis/gluconeogenesis’ genes and had minor influence on ‘citrate cycle (TCA cycle)’ genes. Thus, our findings offer new insights into the responses of B. coagulans to different lactate stresses. Notably, our RNA-seq dataset constitute a robust database for investigating the functions of genes induced by lactate stress in the future and identify potential targets for genetic engineering to further improve L-lactic acid production by B. coagulans. PMID:25875592

Transcriptomic and metabolomic analysis of copper stress acclimation in Ectocarpus siliculosus highlights signaling and tolerance mechanisms in brown algae

PubMed Central

2014-01-01

Background Brown algae are sessile macro-organisms of great ecological relevance in coastal ecosystems. They evolved independently from land plants and other multicellular lineages, and therefore hold several original ontogenic and metabolic features. Most brown algae grow along the coastal zone where they face frequent environmental changes, including exposure to toxic levels of heavy metals such as copper (Cu). Results We carried out large-scale transcriptomic and metabolomic analyses to decipher the short-term acclimation of the brown algal model E. siliculosus to Cu stress, and compared these data to results known for other abiotic stressors. This comparison demonstrates that Cu induces oxidative stress in E. siliculosus as illustrated by the transcriptomic overlap between Cu and H2O2 treatments. The common response to Cu and H2O2 consisted in the activation of the oxylipin and the repression of inositol signaling pathways, together with the regulation of genes coding for several transcription-associated proteins. Concomitantly, Cu stress specifically activated a set of genes coding for orthologs of ABC transporters, a P1B-type ATPase, ROS detoxification systems such as a vanadium-dependent bromoperoxidase, and induced an increase of free fatty acid contents. Finally we observed, as a common abiotic stress mechanism, the activation of autophagic processes on one hand and the repression of genes involved in nitrogen assimilation on the other hand. Conclusions Comparisons with data from green plants indicate that some processes involved in Cu and oxidative stress response are conserved across these two distant lineages. At the same time the high number of yet uncharacterized brown alga-specific genes induced in response to copper stress underlines the potential to discover new components and molecular interactions unique to these organisms. Of particular interest for future research is the potential cross-talk between reactive oxygen species (ROS)-, myo-inositol-, and oxylipin signaling. PMID:24885189

Transcriptomic and proteomic analyses of a pale-green durum wheat mutant shows variations in photosystem components and metabolic deficiencies under drought stress

PubMed Central

2014-01-01

Background Leaf pigment content is an important trait involved in environmental interactions. In order to determine its impact on drought tolerance in wheat, we characterized a pale-green durum wheat mutant (Triticum turgidum L. var. durum) under contrasting water availability conditions. Results The pale-green mutant was investigated by comparing pigment content and gene/protein expression profiles to wild-type plants at anthesis. Under well-watered (control) conditions the mutant had lower levels of chlorophylls and carotenoids, but higher levels of xanthophyll de-epoxidation compared to wild-type. Transcriptomic analysis under control conditions showed that defense genes (encoding e.g. pathogenesis-related proteins, peroxidases and chitinases) were upregulated in the mutant, suggesting the presence of mild oxidative stress that was compensated without altering the net rate of photosynthesis. Transcriptomic analysis under terminal water stress conditions, revealed the modulation of antioxidant enzymes, photosystem components, and enzymes representing carbohydrate metabolism and the tricarboxylic acid cycle, indicating that the mutant was exposed to greater oxidative stress than the wild-type plants, but had a limited capacity to respond. We also compared the two genotypes under irrigated and rain-fed field conditions over three years, finding that the greater oxidative stress and corresponding molecular changes in the pale-green mutant were associated to a yield reduction. Conclusions This study provides insight on the effect of pigment content in the molecular response to drought. Identified genes differentially expressed under terminal water stress may be valuable for further studies addressing drought resistance in wheat. PMID:24521234

Salt stress responsiveness of a wild cotton species (Gossypium klotzschianum) based on transcriptomic analysis.

PubMed

Wei, Yangyang; Xu, Yanchao; Lu, Pu; Wang, Xingxing; Li, Zhenqing; Cai, Xiaoyan; Zhou, Zhongli; Wang, Yuhong; Zhang, Zhenmei; Lin, Zhongxu; Liu, Fang; Wang, Kunbo

2017-01-01

Cotton is a pioneer of saline land crop, while salt stress still causes its growth inhibition and fiber production decrease. Phenotype identification showed better salt tolerance of a wild diploid cotton species Gossypium klotzschianum. To elucidate the salt-tolerant mechanisms in G. klotzschianum, we firstly detected the changes in hormones, H2O2 and glutathione (GSSH and GSH), then investigated the gene expression pattern of roots and leaves treated with 300 mM NaCl for 0, 3, 12, 48 h, and each time control by RNA-seq on the Illumina-Solexa platform. Physiological determination proved that the significant increase in hormone ABA at 48 h, while that in H2O2 was at 12 h, likewise, the GSH content decrease at 48 h and the GSSH content increase at 48 h, under salt stress. In total, 37,278 unigenes were identified from the transcriptome data, 8,312 and 6,732 differentially expressed genes (DEGs) were discovered to be involved in salt stress tolerance in roots and leaves, respectively. Gene function annotation and expression analysis elucidated hormone biosynthesis and signal transduction, reactive oxygen species (ROS), and salt overly sensitive (SOS) signal transduction related genes revealed the important roles of them in signal transmission, oxidation balance and ion homeostasis in response to salinity stress. This is a report which focuses on primary response to highly salty stress (upto 300 mM NaCl) in cotton using a wild diploid Gossypium species, broadening our understanding of the salt tolerance mechanism in cotton and laying a solid foundation of salt resistant for the genetic improvement of upland cotton with the resistance to salt stress.

Salt stress responsiveness of a wild cotton species (Gossypium klotzschianum) based on transcriptomic analysis

PubMed Central

Wang, Xingxing; Li, Zhenqing; Cai, Xiaoyan; Zhou, Zhongli; Wang, Yuhong; Zhang, Zhenmei; Liu, Fang

2017-01-01

Cotton is a pioneer of saline land crop, while salt stress still causes its growth inhibition and fiber production decrease. Phenotype identification showed better salt tolerance of a wild diploid cotton species Gossypium klotzschianum. To elucidate the salt-tolerant mechanisms in G. klotzschianum, we firstly detected the changes in hormones, H2O2 and glutathione (GSSH and GSH), then investigated the gene expression pattern of roots and leaves treated with 300 mM NaCl for 0, 3, 12, 48 h, and each time control by RNA-seq on the Illumina-Solexa platform. Physiological determination proved that the significant increase in hormone ABA at 48 h, while that in H2O2 was at 12 h, likewise, the GSH content decrease at 48 h and the GSSH content increase at 48 h, under salt stress. In total, 37,278 unigenes were identified from the transcriptome data, 8,312 and 6,732 differentially expressed genes (DEGs) were discovered to be involved in salt stress tolerance in roots and leaves, respectively. Gene function annotation and expression analysis elucidated hormone biosynthesis and signal transduction, reactive oxygen species (ROS), and salt overly sensitive (SOS) signal transduction related genes revealed the important roles of them in signal transmission, oxidation balance and ion homeostasis in response to salinity stress. This is a report which focuses on primary response to highly salty stress (upto 300 mM NaCl) in cotton using a wild diploid Gossypium species, broadening our understanding of the salt tolerance mechanism in cotton and laying a solid foundation of salt resistant for the genetic improvement of upland cotton with the resistance to salt stress. PMID:28552980

Transcriptomic analysis of (group I) Clostridium botulinum ATCC 3502 cold shock response.

PubMed

Dahlsten, Elias; Isokallio, Marita; Somervuo, Panu; Lindström, Miia; Korkeala, Hannu

2014-01-01

Profound understanding of the mechanisms foodborne pathogenic bacteria utilize in adaptation to the environmental stress they encounter during food processing and storage is of paramount importance in design of control measures. Chill temperature is a central control measure applied in minimally processed foods; however, data on the mechanisms the foodborne pathogen Clostridium botulinum activates upon cold stress are scarce. Transcriptomic analysis on the C. botulinum ATCC 3502 strain upon temperature downshift from 37°C to 15°C was performed to identify the cold-responsive gene set of this organism. Significant up- or down-regulation of 16 and 11 genes, respectively, was observed 1 h after the cold shock. At 5 h after the temperature downshift, 199 and 210 genes were up- or down-regulated, respectively. Thus, the relatively small gene set affected initially indicated a targeted acute response to cold shock, whereas extensive metabolic remodeling appeared to take place after prolonged exposure to cold. Genes related to fatty acid biosynthesis, oxidative stress response, and iron uptake and storage were induced, in addition to mechanisms previously characterized as cold-tolerance related in bacteria. Furthermore, several uncharacterized DNA-binding transcriptional regulator-encoding genes were induced, suggesting involvement of novel regulatory mechanisms in the cold shock response of C. botulinum. The role of such regulators, CBO0477 and CBO0558A, in cold tolerance of C. botulinum ATCC 3502 was demonstrated by deteriorated growth of related mutants at 17°C.

Comparative analysis of transcriptomic responses to repeated-dose exposure to 2-MCPD and 3-MCPD in rat kidney, liver and testis.

PubMed

Buhrke, Thorsten; Schultrich, Katharina; Braeuning, Albert; Lampen, Alfonso

2017-08-01

3-Chloro-1,2-propanediol (3-MCPD) and its isomer 2-chloro-1,3-propanediol (2-MCPD) are heat-induced food contaminants present in oil- and fat-containing foodstuff. Kidney and testes are among the main target organs of 3-MCPD. Almost no data on 2-MCPD toxicity are available. Here, transcriptomic responses following repeated-dose exposure of rats to non-toxic doses of 10 mg/kg body weight per day 2-MCPD or 3-MCPD for 28 days were characterized by microarray analysis of kidney, liver, and testes. 3-MCPD exerted more pronounced effects than 2-MCPD in all organs. The limited overlap between the datasets indicates that 2-MCPD and 3-MCPD do not share the same molecular mechanisms of toxicity. By combining transcriptomic data with datasets on proteomic regulation by 3-MCPD, a comprehensive view on 3-MCPD-induced regulation of glucose utilization and oxidative stress response was developed. Bioinformatic analyses revealed that Nrf2 (nuclear factor (erythroid-derived 2)-like 2) signaling is likely to be involved in mediating the oxidative stress response to 3-MCPD. In summary, this study for the first time presents data on alterations in global gene expression by two important food contaminants, 2-MCPD and 3-MCPD. Data demonstrate profound differences between the effects of the two compounds and substantially broaden our knowledge on molecular details of 3-MCPD-induced disturbance of glucose utilization and redox balance. Copyright © 2017 Elsevier Ltd. All rights reserved.

Differential Gene Expression between Leaf and Rhizome in Atractylodes lancea: A Comparative Transcriptome Analysis

PubMed Central

Huang, Qianqian; Huang, Xiao; Deng, Juan; Liu, Hegang; Liu, Yanwen; Yu, Kun; Huang, Bisheng

2016-01-01

The rhizome of Atractylodes lancea is extensively used in the practice of Traditional Chinese Medicine because of its broad pharmacological activities. This study was designed to characterize the transcriptome profiling of the rhizome and leaf of Atractylodes lancea in an attempt to uncover the molecular mechanisms regulating rhizome formation and growth. Over 270 million clean reads were assembled into 92,366 unigenes, 58% of which are homologous with sequences in public protein databases (NR, Swiss-Prot, GO, and KEGG). Analysis of expression levels showed that genes involved in photosynthesis, stress response, and translation were the most abundant transcripts in the leaf, while transcripts involved in stress response, transcription regulation, translation, and metabolism were dominant in the rhizome. Tissue-specific gene analysis identified distinct gene families active in the leaf and rhizome. Differential gene expression analysis revealed a clear difference in gene expression pattern, identifying 1518 up-regulated genes and 3464 down-regulated genes in the rhizome compared with the leaf, including a series of genes related to signal transduction, primary and secondary metabolism. Transcription factor (TF) analysis identified 42 TF families, with 67 and 60 TFs up-regulated in the rhizome and leaf, respectively. A total of 104 unigenes were identified as candidates for regulating rhizome formation and development. These data offer an overview of the gene expression pattern of the rhizome and leaf and provide essential information for future studies on the molecular mechanisms of controlling rhizome formation and growth. The extensive transcriptome data generated in this study will be a valuable resource for further functional genomics studies of A. lancea. PMID:27066021

BRIC-21: Global Transcriptome Profiling to Identify Cellular Stress Mechanisms Responsible for Spaceflight-Induced Antibiotic Resistance

NASA Technical Reports Server (NTRS)

Nicholson, Wayne L.; Fajardo-Cavazos, Patricia

2015-01-01

Comparisons of spaceflight stress responses in Bacillus subtilis spores and Staphylococcus epidermidis cells to ground-based controls will be conducted to uncover alterations in their antibiotic susceptibility.

Dynamics of the Saccharomyces cerevisiae transcriptome during bread dough fermentation.

PubMed

Aslankoohi, Elham; Zhu, Bo; Rezaei, Mohammad Naser; Voordeckers, Karin; De Maeyer, Dries; Marchal, Kathleen; Dornez, Emmie; Courtin, Christophe M; Verstrepen, Kevin J

2013-12-01

The behavior of yeast cells during industrial processes such as the production of beer, wine, and bioethanol has been extensively studied. In contrast, our knowledge about yeast physiology during solid-state processes, such as bread dough, cheese, or cocoa fermentation, remains limited. We investigated changes in the transcriptomes of three genetically distinct Saccharomyces cerevisiae strains during bread dough fermentation. Our results show that regardless of the genetic background, all three strains exhibit similar changes in expression patterns. At the onset of fermentation, expression of glucose-regulated genes changes dramatically, and the osmotic stress response is activated. The middle fermentation phase is characterized by the induction of genes involved in amino acid metabolism. Finally, at the latest time point, cells suffer from nutrient depletion and activate pathways associated with starvation and stress responses. Further analysis shows that genes regulated by the high-osmolarity glycerol (HOG) pathway, the major pathway involved in the response to osmotic stress and glycerol homeostasis, are among the most differentially expressed genes at the onset of fermentation. More importantly, deletion of HOG1 and other genes of this pathway significantly reduces the fermentation capacity. Together, our results demonstrate that cells embedded in a solid matrix such as bread dough suffer severe osmotic stress and that a proper induction of the HOG pathway is critical for optimal fermentation.

RNA-seq analysis of broiler liver transcriptome reveals novel responses to high ambient temperature.

PubMed

Coble, Derrick J; Fleming, Damarius; Persia, Michael E; Ashwell, Chris M; Rothschild, Max F; Schmidt, Carl J; Lamont, Susan J

2014-12-10

In broilers, high ambient temperature can result in reduced feed consumption, digestive inefficiency, impaired metabolism, and even death. The broiler sector of the U.S. poultry industry incurs approximately $52 million in heat-related losses annually. The objective of this study is to characterize the effects of cyclic high ambient temperature on the transcriptome of a metabolically active organ, the liver. This study provides novel insight into the effects of high ambient temperature on metabolism in broilers, because it is the first reported RNA-seq study to characterize the effect of heat on the transcriptome of a metabolic-related tissue. This information provides a platform for future investigations to further elucidate physiologic responses to high ambient temperature and seek methods to ameliorate the negative impacts of heat. Transcriptome sequencing of the livers of 8 broiler males using Illumina HiSeq 2000 technology resulted in 138 million, 100-base pair single end reads, yielding a total of 13.8 gigabases of sequence. Forty genes were differentially expressed at a significance level of P-value < 0.05 and a fold-change ≥ 2 in response to a week of cyclic high ambient temperature with 27 down-regulated and 13 up-regulated genes. Two gene networks were created from the function-based Ingenuity Pathway Analysis (IPA) of the differentially expressed genes: "Cell Signaling" and "Endocrine System Development and Function". The gene expression differences in the liver transcriptome of the heat-exposed broilers reflected physiological responses to decrease internal temperature, reduce hyperthermia-induced apoptosis, and promote tissue repair. Additionally, the differential gene expression revealed a physiological response to regulate the perturbed cellular calcium levels that can result from high ambient temperature exposure. Exposure to cyclic high ambient temperature results in changes at the metabolic, physiologic, and cellular level that can be characterized through RNA-seq analysis of the liver transcriptome of broilers. The findings highlight specific physiologic mechanisms by which broilers reduce the effects of exposure to high ambient temperature. This information provides a foundation for future investigations into the gene networks involved in the broiler stress response and for development of strategies to ameliorate the negative impacts of heat on animal production and welfare.

Analysis of differentially expressed genes and adaptive mechanisms of Prunus triloba Lindl. under alkaline stress.

PubMed

Liu, Jia; Wang, Yongqing; Li, Qingtian

2017-01-01

Prunus triloba Lindl. is a naturally salt-alkaline-tolerant plant with several unique characteristics, and it can be used as the rootstock of Chinese plum ( Prunus salicina Lindl.) in saline-alkaline soils. To comprehensively investigate the alkaline acclimation mechanisms in P. triloba , a series of analyses were conducted under alkaline stress, including analyses of the kinetics of molecular and physiological changes, and leaf microstructure. To understand the kinetics of molecular changes under short-term alkaline stress, we used Illumina HiSeq 2500 platform to identify alkaline stress-related differentially expressed genes (DEGs) in P. triloba . Approximately 53.0 million high-quality clean reads were generated from 59.6 million raw reads, and a total of 124,786 unigenes were obtained after de novo assembly of P. triloba transcriptome data. After alkaline stress treatment, a total of 8948 unigenes were identified as DEGs. Based on these DEGs, a Gene Ontology (GO) enrichment analysis was conducted, suggesting that 28 genes may play an important role in the early alkaline stress response. In addition, analysis of DEGs with the Kyoto Encyclopedia of Genes and Genomes (KEGG) revealed that pathways were significant at different treatment time points. A significant positive correlation was found between the quantitative real-time PCR (qRT-PCR) results and the RNA-Seq data for seven alkaline-related genes, confirming the reliability of the RNA-Seq results. Based on physiological analysis of P. triloba in response to long-term alkaline stress, we found that the internal microstructures of the leaves of P. triloba changed to adapt to long-term alkaline stress. Various physiological indexes indicated that the degree of membrane injury increased with increasing duration of alkaline stress, affecting photosynthesis in P. triloba seedlings. This represents the first investigation into the physiology and transcriptome of P. triloba in response to alkaline stress. The results of this study can enrich the genomic resources available for P. triloba , as well as deepening our understanding of molecular and physiological alkaline tolerance mechanisms in P. triloba . This will also provide new insights into our understanding of alkaline acclimation mechanisms in Chinese plum ( Prunus salicina ) trees.

RNA-Seq Technology and Its Application in Fish Transcriptomics

PubMed Central

Ba, Yi; Zhuang, Qianfeng

2014-01-01

Abstract High-throughput sequencing technologies, also known as next-generation sequencing (NGS) technologies, have revolutionized the way that genomic research is advancing. In addition to the static genome, these state-of-art technologies have been recently exploited to analyze the dynamic transcriptome, and the resulting technology is termed RNA sequencing (RNA-seq). RNA-seq is free from many limitations of other transcriptomic approaches, such as microarray and tag-based sequencing method. Although RNA-seq has only been available for a short time, studies using this method have completely changed our perspective of the breadth and depth of eukaryotic transcriptomes. In terms of the transcriptomics of teleost fishes, both model and non-model species have benefited from the RNA-seq approach and have undergone tremendous advances in the past several years. RNA-seq has helped not only in mapping and annotating fish transcriptome but also in our understanding of many biological processes in fish, such as development, adaptive evolution, host immune response, and stress response. In this review, we first provide an overview of each step of RNA-seq from library construction to the bioinformatic analysis of the data. We then summarize and discuss the recent biological insights obtained from the RNA-seq studies in a variety of fish species. PMID:24380445

Soybean Roots Grown under Heat Stress Show Global Changes in Their Transcriptional and Proteomic Profiles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Valdés-López, Oswaldo; Batek, Josef; Gomez-Hernandez, Nicolas

2016-04-25

Heat stress is likely to be a key factor in the negative impact of climate change on crop production. Roots provide support, water and nutrients to other plant organs. Likewise, roots play an important role in the establishment of symbiotic associations with different microorganisms. Despite the physiological relevance of roots, few studies have examined the response of these plant organs to heat stress. In this study, we performed genome-wide transcriptomic and proteomic analyses on isolated root hairs, which are a single, epidermal cell type, and compared their response to whole roots. We identified 2,013 genes differentially regulated in root hairsmore » in response to heat stress. Our gene regulatory module analysis identified ten, key modules that controlled the majority of the transcriptional response to heat stress. We also conducted proteomic analysis on membrane fractions isolated from roots and root hairs. These experiments identified a variety of proteins whose expression changed within 3 hours of application of heat stress. Most of these proteins were predicted to play a role in thermotolerance, as well as in chromatin remodeling and post-transcriptional regulation. The data presented represent an in-depth analysis of the heat stress response of a single cell type in soybean.« less

Transcriptome analysis of molecular mechanisms responsible for light-stress response in Mythimna separata (Walker)

PubMed Central

Duan, Yun; Gong, ZhongJun; Wu, RenHai; Miao, Jin; Jiang, YueLi; Li, Tong; Wu, XiaoBo; Wu, YuQing

2017-01-01

Light is an important environmental signal for most insects. The Oriental Armyworm, Mythimna separata, is a serious pest of cereal crops worldwide, and is highly sensitive to light signals during its developmental and reproductive stages. However, molecular biological studies of its response to light stress are scarce, and related genomic information is not available. In this study, we sequenced and de novo assembled the transcriptomes of M. separata exposed to four different light conditions: dark, white light (WL), UV light (UVL) and yellow light (YL). A total of 46,327 unigenes with an average size of 571 base pairs (bp) were obtained, among which 24,344 (52.55%) matched to public databases. The numbers of genes differentially expressed between dark vs WL, dark vs UVL, dark vs YL, and UVL vs YL were 12,012, 12,950, 14,855, and 13,504, respectively. These results suggest that light exposure altered gene expression patterns in M. separata. Putative genes involved in phototransduction-fly, phototransduction, circadian rhythm-fly, olfactory transduction, and taste transduction were identified. This study thus identified a series of candidate genes and pathways potentially related to light stress in M. separata. PMID:28345615

Microarray analysis of the abscission-related transcriptome in tomato flower abscission zone in response to auxin depletion

USDA-ARS?s Scientific Manuscript database

Abscission, the separation of organs from the parent plant, results in postharvest quality loss in many fresh produce. The process is initiated by changes in the auxin gradient across the abscission zone (AZ), is triggered by ethylene and may be accelerated by postharvest stresses. Although changes ...

Physiology and transcriptomics of water-deficit stress responses in wheat cultivars TAM 111 and TAM 112.

PubMed

Reddy, Srirama Krishna; Liu, Shuyu; Rudd, Jackie C; Xue, Qingwu; Payton, Paxton; Finlayson, Scott A; Mahan, James; Akhunova, Alina; Holalu, Srinidhi V; Lu, Nanyan

2014-09-01

Hard red winter wheat crops on the U.S. Southern Great Plains often experience moderate to severe drought stress, especially during the grain filling stage, resulting in significant yield losses. Cultivars TAM 111 and TAM 112 are widely cultivated in the region, share parentage and showed superior but distinct adaption mechanisms under water-deficit (WD) conditions. Nevertheless, the physiological and molecular basis of their adaptation remains unknown. A greenhouse study was conducted to understand the differences in the physiological and transcriptomic responses of TAM 111 and TAM 112 to WD stress. Whole-plant data indicated that TAM 112 used more water, produced more biomass and grain yield under WD compared to TAM 111. Leaf-level data at the grain filling stage indicated that TAM 112 had elevated abscisic acid (ABA) content and reduced stomatal conductance and photosynthesis as compared to TAM 111. Sustained WD during the grain filling stage also resulted in greater flag leaf transcriptome changes in TAM 112 than TAM 111. Transcripts associated with photosynthesis, carbohydrate metabolism, phytohormone metabolism, and other dehydration responses were uniquely regulated between cultivars. These results suggested a differential role for ABA in regulating physiological and transcriptomic changes associated with WD stress and potential involvement in the superior adaptation and yield of TAM 112. Copyright © 2014 Elsevier GmbH. All rights reserved.

Genotype-specific physiological and transcriptomic responses to drought stress in Setaria italica (an emerging model for Panicoideae grasses).

PubMed

Tang, Sha; Li, Lin; Wang, Yongqiang; Chen, Qiannan; Zhang, Wenying; Jia, Guanqing; Zhi, Hui; Zhao, Baohua; Diao, Xianmin

2017-08-30

Understanding drought-tolerance mechanisms and identifying genetic dominance are important for crop improvement. Setaria italica, which is extremely drought-tolerant, has been regarded as a model plant for studying stress biology. Moreover, different genotypes of S. italica have evolved various drought-tolerance/avoidance mechanisms that should be elucidated. Physiological and transcriptomic comparisons between drought-tolerant S. italica cultivar 'Yugu1' and drought-sensitive 'An04' were conducted. 'An04' had higher yields and more efficient photosystem activities than 'Yugu1' under well-watered conditions, and this was accompanied by positive brassinosteroid regulatory actions. However, 'An04's growth advantage was severely repressed by drought, while 'Yugu1' maintained normal growth under a water deficiency. High-throughput sequencing suggested that the S. italica transcriptome was severely remodelled by genotype × environment interactions. Expression profiles of genes related to phytohormone metabolism and signalling, transcription factors, detoxification, and other stress-related proteins were characterised, revealing genotype-dependent and -independent drought responses in different S. italica genotypes. Combining our data with drought-tolerance-related QTLs, we identified 20 candidate genes that contributed to germination and early seedling' drought tolerance in S. italica. Our analysis provides a comprehensive picture of how different S. italica genotypes respond to drought, and may be used for the genetic improvement of drought tolerance in Poaceae crops.

Molecular and physiological responses to titanium dioxide ...

EPA Pesticide Factsheets

- Changes in tissue transcriptomes and productivity of Arabidopsis thaliana were investigated during exposure of plants to two widely-used engineered metal oxide nanoparticles, titanium dioxide (nano-titanium) and cerium dioxide (nano-cerium). Microarray analyses confirmed that exposure to either nanoparticle altered the transcriptomes of rosette leaves and roots, with comparatively larger numbers of differentially expressed genes (DEGs) found under nano-titania exposure. Nano-titania induced more DEGs in rosette leaves, whereas roots had more DEGs under nano-ceria exposure. MapMan analyses indicated that while nano-titania up-regulated overall and secondary metabolism in both tissues, metabolic processes under nano-ceria remained mostly unchanged. Gene enrichment analysis indicated that both nanoparticles mainly enriched ontology groups such as responses to stress (abiotic and biotic), and defense responses (pathogens), and responses to endogenous stimuli (hormones). Nano-titania specifically induced genes associated with photosynthesis, whereas nano-ceria induced expression of genes related to activating transcription factors, most notably those belonging to the ethylene responsive element binding protein family. Interestingly, there were also increased numbers of rosette leaves and plant biomass under nano-ceria exposure, but not under nano-titania. Other transcriptomic responses did not clearly relate to responses observed at the organism level. This may b

Transcription expression of immune-related genes from Caligus rogercresseyi evidences host-dependent patterns on Atlantic and coho salmon.

PubMed

Vera-Bizama, Fredy; Valenzuela-Muñoz, Valentina; Gonçalves, Ana Teresa; Marambio, Jorge Pino; Hawes, Christopher; Wadsworth, Simon; Gallardo-Escárate, Cristian

2015-12-01

The transcriptomic response of the sea louse Caligus rogercresseyi during the infestation on Atlantic salmon (Salmo salar) and coho salmon (Oncorhynchus kisutch) was evaluated using 27 genes related to immune response, antioxidant system and secretome. Results showed early responses of TLR/IMD signaling pathway in sea lice infesting Atlantic salmon. Overall, genes associated with oxidative stress responses were upregulated in both host species. This pattern suggests that reactive oxygen species emitted by the host as a response to the infestation, could modulate the sea louse antioxidant system. Secretome-related transcripts evidenced upregulation of trypsins and serpins, mainly associated to Atlantic salmon than coho salmon. Interestingly, cathepsins and trypsin2 were downregulated at 7 days post-infection (dpi) in coho salmon. The principal component analysis revealed an inverse time-dependent pattern based on the different responses of C. rogercresseyi infecting both salmon species. Here, Atlantic salmon strongly modulates the transcriptome responses at earlier infection stages; meanwhile coho salmon reveals a less marked modulation, increasing the transcription activity during the infection process. This study evidences transcriptome differences between two salmon host species and provides pivotal knowledge towards elaborating future control strategies. Copyright © 2015 Elsevier Ltd. All rights reserved.

Soybean Roots Grown under Heat Stress Show Global Changes in Their Transcriptional and Proteomic Profiles

DOE PAGES

Valdés-López, Oswaldo; Batek, Josef; Gomez-Hernandez, Nicolas; ...

2016-04-25

Heat stress is likely to be a key factor in the negative impact of climate change on crop production. Heat stress significantly influences the functions of roots, which provide support, water, and nutrients to other plant organs. Likewise, roots play an important role in the establishment of symbiotic associations with different microorganisms. Despite the physiological relevance of roots, few studies have examined their response to heat stress. Here in this study, we performed genome-wide transcriptomic and proteomic analyses on isolated root hairs, which are a single, epidermal cell type, and compared their response to stripped roots. On average, we identifiedmore » 1849 and 3091 genes differentially regulated in root hairs and stripped roots, respectively, in response to heat stress. Our gene regulatory module analysis identified 10 key modules that might control the majority of the transcriptional response to heat stress. We also conducted proteomic analysis on membrane fractions isolated from root hairs and compared these responses to stripped roots. These experiments identified a variety of proteins whose expression changed within 3 h of application of heat stress. Most of these proteins were predicted to play a significant role in thermo-tolerance, as well as in chromatin remodeling and post-transcriptional regulation. In conclusion, the data presented represent an in-depth analysis of the heat stress response of a single cell type in soybean.« less

Comparative transcriptome analysis of rice seedlings induced by different doses of heavy ion radiation

NASA Astrophysics Data System (ADS)

Zhao, Qian; Sun, Yeqing; Wang, Wei

2016-07-01

Highly ionizing radiation (HZE) in space is considered as a main factor causing biological effects on plant seeds. To investigate the different effects on genome-wide gene expression of low-dose and high-dose ion radiation, we carried out ground-base carbon particle HZE experiments with different cumulative doses (0Gy, 0.2Gy, 2Gy) to rice seeds and then performed comparative transcriptome analysis of the rice seedlings. We identified a total of 2551 and 1464 differentially expressed genes (DEGs) in low-dose and high-dose radiation groups, respectively. Gene ontology analyses indicated that low-dose and high-dose ion radiation both led to multiple physiological and biochemical activities changes in rice. By Gene Ontology analyses, the results showed that only one process-oxidation reduction process was enriched in the biological process category after high-dose ion radiation, while more processes such as response to biotic stimulus, heme binding, tetrapyrrole binding, oxidoreductase activity, catalytic activity and oxidoreductase activity were significantly enriched after low-dose ion radiation. The results indicated that the rice plants only focused on the process of oxidation reduction to response to high-dose ion radiation, whereas it was a coordination of multiple biological processes to response to low-dose ion radiation. To elucidate the transcriptional regulation of radiation stress-responsive genes, we identified several DEGs-encoding TFs. AP2/EREBP, bHLH, C2H2, MYB and WRKY TF families were altered significantly in response to ion radiation. Mapman analysis speculated that the biological effects on rice seedlings caused by the radiation stress might share similar mechanisms with the biotic stress. Our findings highlight important alterations in the expression of radiation response genes, metabolic pathways, and TF-encoding genes in rice seedlings exposed to low-dose and high-dose ion radiation.

Genome-wide expression profiling of maize in response to individual and combined water and nitrogen stresses

PubMed Central

2013-01-01

Background Water and nitrogen are two of the most critical inputs required to achieve the high yield potential of modern corn varieties. Under most agricultural settings however they are often scarce and costly. Fortunately, tremendous progress has been made in the past decades in terms of modeling to assist growers in the decision making process and many tools are now available to achieve more sustainable practices both environmentally and economically. Nevertheless large gaps remain between our empirical knowledge of the physiological changes observed in the field in response to nitrogen and water stresses, and our limited understanding of the molecular processes leading to those changes. Results This work examines in particular the impact of simultaneous stresses on the transcriptome. In a greenhouse setting, corn plants were grown under tightly controlled nitrogen and water conditions, allowing sampling of various tissues and stress combinations. A microarray profiling experiment was performed using this material and showed that the concomitant presence of nitrogen and water limitation affects gene expression to an extent much larger than anticipated. A clustering analysis also revealed how the interaction between the two stresses shapes the patterns of gene expression over various levels of water stresses and recovery. Conclusions Overall, this study suggests that the molecular signature of a specific combination of stresses on the transcriptome might be as unique as the impact of individual stresses, and hence underlines the difficulty to extrapolate conclusions obtained from the study of individual stress responses to more complex settings. PMID:23324127

Transcriptional and metabolomic analysis of Ascophyllum nodosum mediated freezing tolerance in Arabidopsis thaliana

PubMed Central

2012-01-01

Background We have previously shown that lipophilic components (LPC) of the brown seaweed Ascophyllum nodosum (ANE) improved freezing tolerance in Arabidopsis thaliana. However, the mechanism(s) of this induced freezing stress tolerance is largely unknown. Here, we investigated LPC induced changes in the transcriptome and metabolome of A. thaliana undergoing freezing stress. Results Gene expression studies revealed that the accumulation of proline was mediated by an increase in the expression of the proline synthesis genes P5CS1 and P5CS2 and a marginal reduction in the expression of the proline dehydrogenase (ProDH) gene. Moreover, LPC application significantly increased the concentration of total soluble sugars in the cytosol in response to freezing stress. Arabidopsis sfr4 mutant plants, defective in the accumulation of free sugars, treated with LPC, exhibited freezing sensitivity similar to that of untreated controls. The 1H NMR metabolite profile of LPC-treated Arabidopsis plants exposed to freezing stress revealed a spectrum dominated by chemical shifts (δ) representing soluble sugars, sugar alcohols, organic acids and lipophilic components like fatty acids, as compared to control plants. Additionally, 2D NMR spectra suggested an increase in the degree of unsaturation of fatty acids in LPC treated plants under freezing stress. These results were supported by global transcriptome analysis. Transcriptome analysis revealed that LPC treatment altered the expression of 1113 genes (5%) in comparison with untreated plants. A total of 463 genes (2%) were up regulated while 650 genes (3%) were down regulated. Conclusion Taken together, the results of the experiments presented in this paper provide evidence to support LPC mediated freezing tolerance enhancement through a combination of the priming of plants for the increased accumulation of osmoprotectants and alteration of cellular fatty acid composition. PMID:23171218

Unraveling the Root Proteome Changes and Its Relationship to Molecular Mechanism Underlying Salt Stress Response in Radish (Raphanus sativus L.)

PubMed Central

Sun, Xiaochuan; Wang, Yan; Xu, Liang; Li, Chao; Zhang, Wei; Luo, Xiaobo; Jiang, Haiyan; Liu, Liwang

2017-01-01

To understand the molecular mechanism underlying salt stress response in radish, iTRAQ-based proteomic analysis was conducted to investigate the differences in protein species abundance under different salt treatments. In total, 851, 706, and 685 differential abundance protein species (DAPS) were identified between CK vs. Na100, CK vs. Na200, and Na100 vs. Na200, respectively. Functional annotation analysis revealed that salt stress elicited complex proteomic alterations in radish roots involved in carbohydrate and energy metabolism, protein metabolism, signal transduction, transcription regulation, stress and defense and transport. Additionally, the expression levels of nine genes encoding DAPS were further verified using RT-qPCR. The integrative analysis of transcriptomic and proteomic data in conjunction with miRNAs was further performed to strengthen the understanding of radish response to salinity. The genes responsible for signal transduction, ROS scavenging and transport activities as well as several key miRNAs including miR171, miR395, and miR398 played crucial roles in salt stress response in radish. Based on these findings, a schematic genetic regulatory network of salt stress response was proposed. This study provided valuable insights into the molecular mechanism underlying salt stress response in radish roots and would facilitate developing effective strategies toward genetically engineered salt-tolerant radish and other root vegetable crops. PMID:28769938

Transcriptome Analysis of Al-Induced Genes in Buckwheat (Fagopyrum esculentum Moench) Root Apex: New Insight into Al Toxicity and Resistance Mechanisms in an Al Accumulating Species

PubMed Central

Xu, Jia Meng; Fan, Wei; Jin, Jian Feng; Lou, He Qiang; Chen, Wei Wei; Yang, Jian Li; Zheng, Shao Jian

2017-01-01

Relying on Al-activated root oxalate secretion, and internal detoxification and accumulation of Al, buckwheat is highly Al resistant. However, the molecular mechanisms responsible for these processes are still poorly understood. It is well-known that root apex is the critical region of Al toxicity that rapidly impairs a series of events, thus, resulting in inhibition of root elongation. Here, we carried out transcriptome analysis of the buckwheat root apex (0–1 cm) with regards to early response (first 6 h) to Al stress (20 μM), which is crucial for identification of both genes and processes involved in Al toxicity and tolerance mechanisms. We obtained 34,469 unigenes with 26,664 unigenes annotated in the NCBI database, and identified 589 up-regulated and 255 down-regulated differentially expressed genes (DEGs) under Al stress. Functional category analysis revealed that biological processes differ between up- and down-regulated genes, although ‘metabolic processes’ were the most affected category in both up- and down-regulated DEGs. Based on the data, it is proposed that Al stress affects a variety of biological processes that collectively contributes to the inhibition of root elongation. We identified 30 transporter genes and 27 transcription factor (TF) genes induced by Al. Gene homology analysis highlighted candidate genes encoding transporters associated with Al uptake, transport, detoxification, and accumulation. We also found that TFs play critical role in transcriptional regulation of Al resistance genes in buckwheat. In addition, gene duplication events are very common in the buckwheat genome, suggesting a possible role for gene duplication in the species’ high Al resistance. Taken together, the transcriptomic analysis of buckwheat root apex shed light on the processes that contribute to the inhibition of root elongation. Furthermore, the comprehensive analysis of both transporter genes and TF genes not only deep our understanding on the responses of buckwheat roots to Al toxicity but provide a good start for functional characterization of genes critical for Al tolerance. PMID:28702047

Transcriptome Analysis of Al-Induced Genes in Buckwheat (Fagopyrum esculentum Moench) Root Apex: New Insight into Al Toxicity and Resistance Mechanisms in an Al Accumulating Species.

PubMed

Xu, Jia Meng; Fan, Wei; Jin, Jian Feng; Lou, He Qiang; Chen, Wei Wei; Yang, Jian Li; Zheng, Shao Jian

2017-01-01

Relying on Al-activated root oxalate secretion, and internal detoxification and accumulation of Al, buckwheat is highly Al resistant. However, the molecular mechanisms responsible for these processes are still poorly understood. It is well-known that root apex is the critical region of Al toxicity that rapidly impairs a series of events, thus, resulting in inhibition of root elongation. Here, we carried out transcriptome analysis of the buckwheat root apex (0-1 cm) with regards to early response (first 6 h) to Al stress (20 μM), which is crucial for identification of both genes and processes involved in Al toxicity and tolerance mechanisms. We obtained 34,469 unigenes with 26,664 unigenes annotated in the NCBI database, and identified 589 up-regulated and 255 down-regulated differentially expressed genes (DEGs) under Al stress. Functional category analysis revealed that biological processes differ between up- and down-regulated genes, although 'metabolic processes' were the most affected category in both up- and down-regulated DEGs. Based on the data, it is proposed that Al stress affects a variety of biological processes that collectively contributes to the inhibition of root elongation. We identified 30 transporter genes and 27 transcription factor (TF) genes induced by Al. Gene homology analysis highlighted candidate genes encoding transporters associated with Al uptake, transport, detoxification, and accumulation. We also found that TFs play critical role in transcriptional regulation of Al resistance genes in buckwheat. In addition, gene duplication events are very common in the buckwheat genome, suggesting a possible role for gene duplication in the species' high Al resistance. Taken together, the transcriptomic analysis of buckwheat root apex shed light on the processes that contribute to the inhibition of root elongation. Furthermore, the comprehensive analysis of both transporter genes and TF genes not only deep our understanding on the responses of buckwheat roots to Al toxicity but provide a good start for functional characterization of genes critical for Al tolerance.

Isolation of Polysomal RNA for Analyzing Stress-Responsive Genes Regulated at the Translational Level in Plants.

PubMed

Li, Yong-Fang; Mahalingam, Ramamurthy; Sunkar, Ramanjulu

2017-01-01

Alteration of gene expression is an essential mechanism, which allows plants to respond and adapt to adverse environmental conditions. Transcriptome and proteome analyses in plants exposed to abiotic stresses revealed that protein levels are not correlated with the changes in corresponding mRNAs, indicating regulation at translational level is another major regulator for gene expression. Analysis of translatome, which refers to all mRNAs associated with ribosomes, thus has the potential to bridge the gap between transcriptome and proteome. Polysomal RNA profiling and recently developed ribosome profiling (Ribo-seq) are two main methods for translatome analysis at global level. Here, we describe the classical procedure for polysomal RNA isolation by sucrose gradient ultracentrifugation followed by highthroughput RNA-seq to identify genes regulated at translational level. Polysomal RNA can be further used for a variety of downstream applications including Northern blot analysis, qRT-PCR, RNase protection assay, and microarray-based gene expression profiling.

Transcriptome and Molecular Pathway Analysis of the Hepatopancreas in the Pacific White Shrimp Litopenaeus vannamei under Chronic Low-Salinity Stress

PubMed Central

Chen, Ke; Li, Erchao; Li, Tongyu; Xu, Chang; Wang, Xiaodan; Lin, Heizhao; Qin, Jian G.; Chen, Liqiao

2015-01-01

The Pacific white shrimp Litopenaeus vannamei is a euryhaline penaeid species that shows ontogenetic adaptations to salinity, with its larvae inhabiting oceanic environments and postlarvae and juveniles inhabiting estuaries and lagoons. Ontogenetic adaptations to salinity manifest in L. vannamei through strong hyper-osmoregulatory and hypo-osmoregulatory patterns and an ability to tolerate extremely low salinity levels. To understand this adaptive mechanism to salinity stress, RNA-seq was used to compare the transcriptomic response of L. vannamei to changes in salinity from 30 (control) to 3 practical salinity units (psu) for 8 weeks. In total, 26,034 genes were obtained from the hepatopancreas tissue of L. vannamei using the Illumina HiSeq 2000 system, and 855 genes showed significant changes in expression under salinity stress. Eighteen top Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were significantly involved in physiological responses, particularly in lipid metabolism, including fatty-acid biosynthesis, arachidonic acid metabolism and glycosphingolipid and glycosaminoglycan metabolism. Lipids or fatty acids can reduce osmotic stress in L. vannamei by providing additional energy or changing the membrane structure to allow osmoregulation in relevant organs, such as the gills. Steroid hormone biosynthesis and the phosphonate and phosphinate metabolism pathways were also involved in the adaptation of L. vannamei to low salinity, and the differential expression patterns of 20 randomly selected genes were validated by quantitative real-time PCR (qPCR). This study is the first report on the long-term adaptive transcriptomic response of L. vannamei to low salinity, and the results will further our understanding of the mechanisms underlying osmoregulation in euryhaline crustaceans. PMID:26147449

Updated Rice Kinase Database RKD 2.0: enabling transcriptome and functional analysis of rice kinase genes.

PubMed

Chandran, Anil Kumar Nalini; Yoo, Yo-Han; Cao, Peijian; Sharma, Rita; Sharma, Manoj; Dardick, Christopher; Ronald, Pamela C; Jung, Ki-Hong

2016-12-01

Protein kinases catalyze the transfer of a phosphate moiety from a phosphate donor to the substrate molecule, thus playing critical roles in cell signaling and metabolism. Although plant genomes contain more than 1000 genes that encode kinases, knowledge is limited about the function of each of these kinases. A major obstacle that hinders progress towards kinase characterization is functional redundancy. To address this challenge, we previously developed the rice kinase database (RKD) that integrated omics-scale data within a phylogenetics context. An updated version of rice kinase database (RKD) that contains metadata derived from NCBI GEO expression datasets has been developed. RKD 2.0 facilitates in-depth transcriptomic analyses of kinase-encoding genes in diverse rice tissues and in response to biotic and abiotic stresses and hormone treatments. We identified 261 kinases specifically expressed in particular tissues, 130 that are significantly up- regulated in response to biotic stress, 296 in response to abiotic stress, and 260 in response to hormones. Based on this update and Pearson correlation coefficient (PCC) analysis, we estimated that 19 out of 26 genes characterized through loss-of-function studies confer dominant functions. These were selected because they either had paralogous members with PCC values of <0.5 or had no paralog. Compared with the previous version of RKD, RKD 2.0 enables more effective estimations of functional redundancy or dominance because it uses comprehensive expression profiles rather than individual profiles. The integrated analysis of RKD with PCC establishes a single platform for researchers to select rice kinases for functional analyses.

De novo transcriptome assembly and comparative analysis of differentially expressed genes in Prunus dulcis Mill. in response to freezing stress.

PubMed

Mousavi, Sadegh; Alisoltani, Arghavan; Shiran, Behrouz; Fallahi, Hossein; Ebrahimie, Esameil; Imani, Ali; Houshmand, Saadollah

2014-01-01

Almond (Prunus dulcis Mill.), one of the most important nut crops, requires chilling during winter to develop fruiting buds. However, early spring chilling and late spring frost may damage the reproductive tissues leading to reduction in the rate of productivity. Despite the importance of transcriptional changes and regulation, little is known about the almond's transcriptome under the cold stress conditions. In the current research, we used RNA-seq technique to study the response of the reproductive tissues of almond (anther and ovary) to frost stress. RNA sequencing resulted in more than 20 million reads from anther and ovary tissues of almond, individually. About 40,000 contigs were assembled and annotated de novo in each tissue. Profile of gene expression in ovary showed significant alterations in 5,112 genes, whereas in anther 6,926 genes were affected by freezing stress. Around two thousands of these genes were common altered genes in both ovary and anther libraries. Gene ontology indicated the involvement of differentially expressed (DE) genes, responding to freezing stress, in metabolic and cellular processes. qRT-PCR analysis verified the expression pattern of eight genes randomly selected from the DE genes. In conclusion, the almond gene index assembled in this study and the reported DE genes can provide great insights on responses of almond and other Prunus species to abiotic stresses. The obtained results from current research would add to the limited available information on almond and Rosaceae. Besides, the findings would be very useful for comparative studies as the number of DE genes reported here is much higher than that of any previous reports in this plant.

De Novo Transcriptome Assembly and Comparative Analysis of Differentially Expressed Genes in Prunus dulcis Mill. in Response to Freezing Stress

PubMed Central

Shiran, Behrouz; Fallahi, Hossein; Ebrahimie, Esameil; Imani, Ali; Houshmand, Saadollah

2014-01-01

Almond (Prunus dulcis Mill.), one of the most important nut crops, requires chilling during winter to develop fruiting buds. However, early spring chilling and late spring frost may damage the reproductive tissues leading to reduction in the rate of productivity. Despite the importance of transcriptional changes and regulation, little is known about the almond’s transcriptome under the cold stress conditions. In the current reserch, we used RNA-seq technique to study the response of the reporuductive tissues of almond (anther and ovary) to frost stress. RNA sequencing resulted in more than 20 million reads from anther and ovary tissues of almond, individually. About 40,000 contigs were assembled and annotated de novo in each tissue. Profile of gene expression in ovary showed significant alterations in 5,112 genes, whereas in anther 6,926 genes were affected by freezing stress. Around two thousands of these genes were common altered genes in both ovary and anther libraries. Gene ontology indicated the involvement of differentially expressed (DE) genes, responding to freezing stress, in metabolic and cellular processes. qRT-PCR analysis verified the expression pattern of eight genes randomley selected from the DE genes. In conclusion, the almond gene index assembled in this study and the reported DE genes can provide great insights on responses of almond and other Prunus species to abiotic stresses. The obtained results from current research would add to the limited available information on almond and Rosaceae. Besides, the findings would be very useful for comparative studies as the number of DE genes reported here is much higher than that of any previous reports in this plant. PMID:25122458

SAGE Analysis of Transcriptome Responses in Arabidopsis Roots Exposed to 2,4,6-Trinitrotoluene1

PubMed Central

Ekman, Drew R.; Lorenz, W. Walter; Przybyla, Alan E.; Wolfe, N. Lee; Dean, Jeffrey F.D.

2003-01-01

Serial analysis of gene expression was used to profile transcript levels in Arabidopsis roots and assess their responses to 2,4,6-trinitrotoluene (TNT) exposure. SAGE libraries representing control and TNT-exposed seedling root transcripts were constructed, and each was sequenced to a depth of roughly 32,000 tags. More than 19,000 unique tags were identified overall. The second most highly induced tag (27-fold increase) represented a glutathione S-transferase. Cytochrome P450 enzymes, as well as an ABC transporter and a probable nitroreductase, were highly induced by TNT exposure. Analyses also revealed an oxidative stress response upon TNT exposure. Although some increases were anticipated in light of current models for xenobiotic metabolism in plants, evidence for unsuspected conjugation pathways was also noted. Identifying transcriptome-level responses to TNT exposure will better define the metabolic pathways plants use to detoxify this xenobiotic compound, which should help improve phytoremediation strategies directed at TNT and other nitroaromatic compounds. PMID:14551330

Comparative transcriptome analysis of the CO2 sensing pathway via differential expression of carbonic anhydrase in Cryptococcus neoformans.

PubMed

Kim, Min Su; Ko, Young-Joon; Maeng, Shinae; Floyd, Anna; Heitman, Joseph; Bahn, Yong-Sun

2010-08-01

Carbon dioxide (CO(2)) sensing and metabolism via carbonic anhydrases (CAs) play pivotal roles in survival and proliferation of pathogenic fungi infecting human hosts from natural environments due to the drastic difference in CO(2) levels. In Cryptococcus neoformans, which causes fatal fungal meningoencephalitis, the Can2 CA plays essential roles during both cellular growth in air and sexual differentiation of the pathogen. However the signaling networks downstream of Can2 are largely unknown. To address this question, the present study employed comparative transcriptome DNA microarray analysis of a C. neoformans strain in which CAN2 expression is artificially controlled by the CTR4 (copper transporter) promoter. The P(CTR4)CAN2 strain showed growth defects in a CO(2)-dependent manner when CAN2 was repressed but resumed normal growth when CAN2 was overexpressed. The Can2-dependent genes identified by the transcriptome analysis include FAS1 (fatty acid synthase 1) and GPB1 (G-protein beta subunit), supporting the roles of Can2 in fatty acid biosynthesis and sexual differentiation. Cas3, a capsular structure designer protein, was also discovered to be Can2-dependent and yet was not involved in CO(2)-mediated capsule induction. Most notably, a majority of Can2-dependent genes were environmental stress-regulated (ESR) genes. Supporting this, the CAN2 overexpression strain was hypersensitive to oxidative and genotoxic stress as well as antifungal drugs, such as polyene and azole drugs, potentially due to defective membrane integrity. Finally, an oxidative stress-responsive Atf1 transcription factor was also found to be Can2-dependent. Atf1 not only plays an important role in diverse stress responses, including thermotolerance and antifungal drug resistance, but also represses melanin and capsule production in C. neoformans. In conclusion, this study provides insights into the comprehensive signaling networks orchestrated by CA/CO(2)-sensing pathways in pathogenic fungi.

Transcriptome assembly and expression profiling of the molecular responses to cadmium toxicity in cerebral ganglia of wolf spider Pardosa pseudoannulata (Araneae: Lycosidae).

PubMed

Yang, Huilin; Peng, Yuande; Shi, Yixue; Tian, Jianxiang; Wang, Juan; Peng, Xianjin; Xie, Chunliang; Xu, Xiang; Song, Qisheng; Wang, Zhi; Lv, Zhiyue

2018-03-01

Cadmium (Cd) is a heavy metal that can cause irreversible toxicity to animals, and is an environmental pollutant in farmlands. Spiders are considered to be an excellent model for investigating the impacts of heavy metals on the environment. To date, the changes at the molecular level in the cerebral ganglia of spiders are poorly understood. Cd exposure leads to strong damage in the nervous system, such as apoptosis and necrosis of nerve cells, therefore we conducted a transcriptomic analysis of Pardosa pseudoannulata cerebral ganglia under Cd stress to profile differential gene expression (DGE). We obtained a total of 123,328 assembled unigenes, and 1441 Cd stress-associated DEGs between the Cd-treated and control groups. Expression profile analysis demonstrated that many genes involved in calcium signaling, cGMP-PKG signaling, tyrosine metabolism, phototransduction-fly, melanogenesis and isoquinoline alkaloid biosynthesis were up-regulated under Cd stress, whereas oxidative phosphorylation-related, nervous disease-associated, non-alcoholic fatty liver disease-associated, and ribosomal-associated genes were down-regulated. Here, we provide a comprehensive set of DEGs influenced by Cd stress, and heavy metal stress, and provide new information for elucidating the neurotoxic mechanisms of Cd stress in spiders.

Molecular signatures in Arabidopsis thaliana in response to insect attack and bacterial infection.

PubMed

Barah, Pankaj; Winge, Per; Kusnierczyk, Anna; Tran, Diem Hong; Bones, Atle M

2013-01-01

Under the threat of global climatic change and food shortages, it is essential to take the initiative to obtain a comprehensive understanding of common and specific defence mechanisms existing in plant systems for protection against different types of biotic invaders. We have implemented an integrated approach to analyse the overall transcriptomic reprogramming and systems-level defence responses in the model plant species Arabidopsis thaliana (A. thaliana henceforth) during insect Brevicoryne brassicae (B. brassicae henceforth) and bacterial Pseudomonas syringae pv. tomato strain DC3000 (P. syringae henceforth) attacks. The main aim of this study was to identify the attacker-specific and general defence response signatures in A. thaliana when attacked by phloem-feeding aphids or pathogenic bacteria. The obtained annotated networks of differentially expressed transcripts indicated that members of transcription factor families, such as WRKY, MYB, ERF, BHLH and bZIP, could be crucial for stress-specific defence regulation in Arabidopsis during aphid and P. syringae attack. The defence response pathways, signalling pathways and metabolic processes associated with aphid attack and P. syringae infection partially overlapped. Components of several important biosynthesis and signalling pathways, such as salicylic acid (SA), jasmonic acid (JA), ethylene (ET) and glucosinolates, were differentially affected during the two the treatments. Several stress-regulated transcription factors were known to be associated with stress-inducible microRNAs. The differentially regulated gene sets included many signature transcription factors, and our co-expression analysis showed that they were also strongly co-expressed during 69 other biotic stress experiments. Defence responses and functional networks that were unique and specific to aphid or P. syringae stresses were identified. Furthermore, our analysis revealed a probable link between biotic stress and microRNAs in Arabidopsis and, thus gives indicates a new direction for conducting large-scale targeted experiments to explore the detailed regulatory links between them. The presented results provide a comparative understanding of Arabidopsis - B. brassicae and Arabidopsis - P. syringae interactions at the transcriptomic level.

Comparative Transcriptome Analysis of Shoots and Roots of TNG67 and TCN1 Rice Seedlings under Cold Stress and Following Subsequent Recovery: Insights into Metabolic Pathways, Phytohormones, and Transcription Factors

PubMed Central

Yang, Yun-Wei; Chen, Hung-Chi; Jen, Wei-Fu; Liu, Li-Yu; Chang, Men-Chi

2015-01-01

Cold stress affects rice growth, quality and yield. The investigation of genome-wide gene expression is important for understanding cold stress tolerance in rice. We performed comparative transcriptome analysis of the shoots and roots of 2 rice seedlings (TNG67, cold-tolerant; and TCN1, cold-sensitive) in response to low temperatures and restoration of normal temperatures following cold exposure. TNG67 tolerated cold stress via rapid alterations in gene expression and the re-establishment of homeostasis, whereas the opposite was observed in TCN1, especially after subsequent recovery. Gene ontology and pathway analyses revealed that cold stress substantially regulated the expression of genes involved in protein metabolism, modification, translation, stress responses, and cell death. TNG67 takes advantage of energy-saving and recycling resources to more efficiently synthesize metabolites compared with TCN1 during adjustment to cold stress. During recovery, expression of OsRR4 type-A response regulators was upregulated in TNG67 shoots, whereas that of genes involved in oxidative stress, chemical stimuli and carbohydrate metabolic processes was downregulated in TCN1. Expression of genes related to protein metabolism, modification, folding and defense responses was upregulated in TNG67 but not in TCN1 roots. In addition, abscisic acid (ABA)-, polyamine-, auxin- and jasmonic acid (JA)-related genes were preferentially regulated in TNG67 shoots and roots and were closely associated with cold stress tolerance. The TFs AP2/ERF were predominantly expressed in the shoots and roots of both TNG67 and TCN1. The TNG67-preferred TFs which express in shoot or root, such as OsIAA23, SNAC2, OsWRKY1v2, 24, 53, 71, HMGB, OsbHLH and OsMyb, may be good candidates for cold stress tolerance-related genes in rice. Our findings highlight important alterations in the expression of cold-tolerant genes, metabolic pathways, and hormone-related and TF-encoding genes in TNG67 rice during cold stress and recovery. The cross-talk of hormones may play an essential role in the ability of rice plants to cope with cold stress. PMID:26133169

De novo transcriptome sequencing of two cultivated jute species under salinity stress

PubMed Central

Dai, Zhigang; Tang, Qing; Cheng, Chaohua; Xu, Ying

2017-01-01

Soil salinity, a major environmental stress, reduces agricultural productivity by restricting plant development and growth. Jute (Corchorus spp.), a commercially important bast fiber crop, includes two commercially cultivated species, Corchorus capsularis and Corchorus olitorius. We conducted high-throughput transcriptome sequencing of 24 C. capsularis and C. olitorius samples under salt stress and found 127 common differentially expressed genes (DEGs); additionally, 4489 and 492 common DEGs were identified in the root and leaf tissues, respectively, of both Corchorus species. Further, 32, 196, and 11 common differentially expressed transcription factors (DTFs) were detected in the leaf, root, or both tissues, respectively. Several Gene Ontology (GO) terms were enriched in NY and YY. A Kyoto Encyclopedia of Genes and Genomes analysis revealed numerous DEGs in both species. Abscisic acid and cytokinin signal pathways enriched respectively about 20 DEGs in leaves and roots of both NY and YY. The Ca2+, mitogen-activated protein kinase signaling and oxidative phosphorylation pathways were also found to be related to the plant response to salt stress, as evidenced by the DEGs in the roots of both species. These results provide insight into salt stress response mechanisms in plants as well as a basis for future breeding of salt-tolerant cultivars. PMID:29059212

Mongolian Almond (Prunus mongolica Maxim): The Morpho-Physiological, Biochemical and Transcriptomic Response to Drought Stress

PubMed Central

Bai, Shulan; Gao, Xiaomin; Liu, Min; Yan, Wei

2015-01-01

Prunus mongolica Maxim, which is widely established in the Gobi Desert, shows extreme tolerance to drought. However, there is a lack of available transcriptomic resources for this species related to its response to water deficiency. To investigate the mechanisms that allow P. mongolica to maintain growth in extremely arid environments, the response of P. mongolica seedlings to drought stress was analyzed using morphological, physiological, biochemical and high-throughput sequencing approaches. We generated 28,713,735 and 26,650,133 raw reads from no-stress control and drought-stressed P. mongolica seedlings, respectively. In total, we obtained 67,352 transcripts with an average length of 874.44 bp. Compared with the no-stress control, 3,365 transcripts were differentially expressed in the drought-stressed seedlings, including 55.75% (1,876 transcripts) up-regulated and 44.25% (1,489 transcripts) down-regulated transcripts. The photosynthesis response showed a decreasing tendency under drought stress, but the changes in the levels of hormones (auxins, cytokinins and abscisic acid) resulted in the closing of stomata and decreased cell enlargement and division; these changes were effective for promoting P. mongolica survival in Gobi Desert. Next, we analyzed the aquaporin and superoxide dismutase gene families due to their importance in plant resistance to drought stress. We found that all of the plasma membrane intrinsic protein transcripts were down-regulated in the drought-stressed treatment, whereas drought did not affect the expression of nodulin intrinsic protein or small basic intrinsic protein transcripts in P. mongolica seedlings. In addition, activation of iron superoxide dismutase transcription and enhanced transcription of manganese superoxide dismutase were observed in P. mongolica to promote tolerance of drought stress. This study identified drought response genes in P. mongolica seedlings. Our results provide a significant contribution to the understanding of how P. mongolica responds to drought stress at the transcriptome level, which may help to elucidate molecular mechanisms associated with the drought response of almond plants. PMID:25893685

Cryptic diversity in the estuarine copepod Acartia tonsa: reproductive isolation and lineage-specific divergence in transcriptomic response to salinity stress

NASA Astrophysics Data System (ADS)

Plough, L. V.

2016-02-01

Discovery of the near ubiquity of cryptic species among planktonic taxa marks a major advance in marine science over the last two decades. However, little is known about the potential drivers of divergence among species, and particularly how cryptic taxa may respond differentially to environmental stress as climate change and ocean acidification proceed. Here we report results from experimental studies characterizing reproduction and transcriptomic response to stress in Acartia tonsa, a dominant estuarine copepod that exhibits three sympatric (but morphologically cryptic) lineages that sort by salinity along the US Atlantic coast (lineage F - fresh, S - saline, and X - intermediate). Pair crosses between F and S individuals collected from Chesapeake Bay at a common ambient salinity (13ppt) revealed that while inter-lineage (FxS) crosses produced eggs, only eggs from intra-lineage (FxF or SxS) crosses successfully hatched. Analysis of whether 'hybrid' eggs were fertilized and failed to develop or did not fertilize, which could indicate pre vs post-zygotic isolation, is ongoing. Exposing replicate groups of 2nd gen. lab-cultured F and S individuals to ambient and low salinity (7 ppt) stress produced very different patterns of gene expression measured with RNAseq. First, the dynamic range of expression was much greater in the S lineage overall (both salinities), with more differentially expressed genes (DEG's) in comparisons of low vs control salinity (232 vs 77 DEGs at 0.01 FDR level for S, and F respectively). Gene ontology analysis of DEG function revealed a more targeted response in F to ion stress (up and down regulation of genes involved in ion transport, catalytic activity, and binding) while the S lineage showed a more varied and general response (up-regulation of metabolism, nucleic acid synthesis, and general stress response). Overall, these experiments confirm reproductive isolation among two cryptic A. tonsa ineages and identify key differences in thier physiological response to salinity stress. Future work will examine lineage-specific responses to other significant stressors such as hypoxia.

The Transcriptional Responses and Metabolic Consequences of Acclimation to Elevated Light Exposure in Grapevine Berries

PubMed Central

du Plessis, Kari; Young, Philip R.; Eyéghé-Bickong, Hans A.; Vivier, Melané A.

2017-01-01

An increasing number of field studies that focus on grapevine berry development and ripening implement systems biology approaches; the results are highlighting not only the intricacies of the developmental programming/reprogramming that occurs, but also the complexity of how profoundly the microclimate influences the metabolism of the berry throughout the different stages of development. In a previous study we confirmed that a leaf removal treatment to Sauvignon Blanc grapes, grown in a highly characterized vineyard, primarily affected the level of light exposure to the berries throughout their development. A full transcriptomic analysis of berries from this model vineyard details the underlying molecular responses of the berries in reaction to the exposure and show how the berries acclimated to the imposing light stress. Gene expression involved in the protection of the photosynthetic machinery through rapid protein-turnover and the expression of photoprotective flavonoid compounds were most significantly affected in green berries. Overall, the transcriptome analysis showed that the berries implemented multiple stress-mitigation strategies in parallel and metabolite analysis was used to support the main findings. Combining the transcriptome data and amino acid profiling provided evidence that amino acid catabolism probably contributed to the mitigation of a likely energetic deficit created by the upregulation of (energetically) costly stress defense mechanisms. Furthermore, the rapid turnover of essential proteins involved in the maintenance of primary metabolism and growth in the photosynthetically active grapes appeared to provide precursors for the production of protective secondary metabolites such as apocarotenoids and flavonols in the ripening stages of the berries. Taken together, these results confirmed that the green grape berries responded to light stress much like other vegetative organs and were able to acclimate to the increased exposure, managing their metabolism and energy requirements to sustain the developmental cycle toward ripening. The typical metabolic consequences of leaf removal on grape berries can therefore now be linked to increased light exposure through mechanisms of photoprotection in green berries that leads toward acclimation responses that remain intact until ripening. PMID:28775728

The Transcriptional Responses and Metabolic Consequences of Acclimation to Elevated Light Exposure in Grapevine Berries.

PubMed

du Plessis, Kari; Young, Philip R; Eyéghé-Bickong, Hans A; Vivier, Melané A

2017-01-01

An increasing number of field studies that focus on grapevine berry development and ripening implement systems biology approaches; the results are highlighting not only the intricacies of the developmental programming/reprogramming that occurs, but also the complexity of how profoundly the microclimate influences the metabolism of the berry throughout the different stages of development. In a previous study we confirmed that a leaf removal treatment to Sauvignon Blanc grapes, grown in a highly characterized vineyard, primarily affected the level of light exposure to the berries throughout their development. A full transcriptomic analysis of berries from this model vineyard details the underlying molecular responses of the berries in reaction to the exposure and show how the berries acclimated to the imposing light stress. Gene expression involved in the protection of the photosynthetic machinery through rapid protein-turnover and the expression of photoprotective flavonoid compounds were most significantly affected in green berries. Overall, the transcriptome analysis showed that the berries implemented multiple stress-mitigation strategies in parallel and metabolite analysis was used to support the main findings. Combining the transcriptome data and amino acid profiling provided evidence that amino acid catabolism probably contributed to the mitigation of a likely energetic deficit created by the upregulation of (energetically) costly stress defense mechanisms. Furthermore, the rapid turnover of essential proteins involved in the maintenance of primary metabolism and growth in the photosynthetically active grapes appeared to provide precursors for the production of protective secondary metabolites such as apocarotenoids and flavonols in the ripening stages of the berries. Taken together, these results confirmed that the green grape berries responded to light stress much like other vegetative organs and were able to acclimate to the increased exposure, managing their metabolism and energy requirements to sustain the developmental cycle toward ripening. The typical metabolic consequences of leaf removal on grape berries can therefore now be linked to increased light exposure through mechanisms of photoprotection in green berries that leads toward acclimation responses that remain intact until ripening.

Bacterial biofilm under flow: First a physical struggle to stay, then a matter of breathing.

PubMed

Thomen, Philippe; Robert, Jérôme; Monmeyran, Amaury; Bitbol, Anne-Florence; Douarche, Carine; Henry, Nelly

2017-01-01

Bacterial communities attached to surfaces under fluid flow represent a widespread lifestyle of the microbial world. Through shear stress generation and molecular transport regulation, hydrodynamics conveys effects that are very different by nature but strongly coupled. To decipher the influence of these levers on bacterial biofilms immersed in moving fluids, we quantitatively and simultaneously investigated physicochemical and biological properties of the biofilm. We designed a millifluidic setup allowing to control hydrodynamic conditions and to monitor biofilm development in real time using microscope imaging. We also conducted a transcriptomic analysis to detect a potential physiological response to hydrodynamics. We discovered that a threshold value of shear stress determined biofilm settlement, with sub-piconewton forces sufficient to prevent biofilm initiation. As a consequence, distinct hydrodynamic conditions, which set spatial distribution of shear stress, promoted distinct colonization patterns with consequences on the growth mode. However, no direct impact of mechanical forces on biofilm growth rate was observed. Consistently, no mechanosensing gene emerged from our differential transcriptomic analysis comparing distinct hydrodynamic conditions. Instead, we found that hydrodynamic molecular transport crucially impacts biofilm growth by controlling oxygen availability. Our results shed light on biofilm response to hydrodynamics and open new avenues to achieve informed design of fluidic setups for investigating, engineering or fighting adherent communities.

Bacterial biofilm under flow: First a physical struggle to stay, then a matter of breathing

PubMed Central

Thomen, Philippe; Robert, Jérôme; Monmeyran, Amaury; Bitbol, Anne-Florence; Douarche, Carine; Henry, Nelly

2017-01-01

Bacterial communities attached to surfaces under fluid flow represent a widespread lifestyle of the microbial world. Through shear stress generation and molecular transport regulation, hydrodynamics conveys effects that are very different by nature but strongly coupled. To decipher the influence of these levers on bacterial biofilms immersed in moving fluids, we quantitatively and simultaneously investigated physicochemical and biological properties of the biofilm. We designed a millifluidic setup allowing to control hydrodynamic conditions and to monitor biofilm development in real time using microscope imaging. We also conducted a transcriptomic analysis to detect a potential physiological response to hydrodynamics. We discovered that a threshold value of shear stress determined biofilm settlement, with sub-piconewton forces sufficient to prevent biofilm initiation. As a consequence, distinct hydrodynamic conditions, which set spatial distribution of shear stress, promoted distinct colonization patterns with consequences on the growth mode. However, no direct impact of mechanical forces on biofilm growth rate was observed. Consistently, no mechanosensing gene emerged from our differential transcriptomic analysis comparing distinct hydrodynamic conditions. Instead, we found that hydrodynamic molecular transport crucially impacts biofilm growth by controlling oxygen availability. Our results shed light on biofilm response to hydrodynamics and open new avenues to achieve informed design of fluidic setups for investigating, engineering or fighting adherent communities. PMID:28403171

Metabolic and transcriptomic signatures of rice floral organs reveal sugar starvation as a factor in reproductive failure under heat and drought stress.

PubMed

Li, Xia; Lawas, Lovely M F; Malo, Richard; Glaubitz, Ulrike; Erban, Alexander; Mauleon, Ramil; Heuer, Sigrid; Zuther, Ellen; Kopka, Joachim; Hincha, Dirk K; Jagadish, Krishna S V

2015-10-01

Heat and drought stress are projected to become major challenges to sustain rice (Oryza sativa L.) yields with global climate change. Both stresses lead to yield losses when they coincide with flowering. A significant knowledge gap exists in the mechanistic understanding of the responses of rice floral organs that determine reproductive success under stress. Our work connects the metabolomic and transcriptomic changes in anthers, pistils before pollination and pollinated pistils in a heat-tolerant (N22) and a heat-sensitive (Moroberekan) cultivar. Systematic analysis of the floral organs revealed contrasts in metabolic profiles across anthers and pistils. Constitutive metabolic markers were identified that can define reproductive success in rice under stress. Six out of nine candidate metabolites identified by intersection analysis of stressed anthers were differentially accumulated in N22 compared with Moroberekan under non-stress conditions. Sugar metabolism was identified to be the crucial metabolic and transcriptional component that differentiated floral organ tolerance or susceptibility to stress. While susceptible Moroberekan specifically showed high expression of the Carbon Starved Anthers (CSA) gene under combined heat and drought, tolerant N22 responded with high expression of genes encoding a sugar transporter (MST8) and a cell wall invertase (INV4) as markers of high sink strength. © 2015 John Wiley & Sons Ltd.

ASR5 is involved in the regulation of miRNA expression in rice.

PubMed

Neto, Lauro Bücker; Arenhart, Rafael Augusto; de Oliveira, Luiz Felipe Valter; de Lima, Júlio Cesar; Bodanese-Zanettini, Maria Helena; Margis, Rogerio; Margis-Pinheiro, Márcia

2015-11-01

The work describes an ASR knockdown transcriptomic analysis by deep sequencing of rice root seedlings and the transactivation of ASR cis-acting elements in the upstream region of a MIR gene. MicroRNAs are key regulators of gene expression that guide post-transcriptional control of plant development and responses to environmental stresses. ASR (ABA, Stress and Ripening) proteins are plant-specific transcription factors with key roles in different biological processes. In rice, ASR proteins have been suggested to participate in the regulation of stress response genes. This work describes the transcriptomic analysis by deep sequencing two libraries, comparing miRNA abundance from the roots of transgenic ASR5 knockdown rice seedlings with that of the roots of wild-type non-transformed rice seedlings. Members of 59 miRNA families were detected, and 276 mature miRNAs were identified. Our analysis detected 112 miRNAs that were differentially expressed between the two libraries. A predicted inverse correlation between miR167abc and its target gene (LOC_Os07g29820) was confirmed using RT-qPCR. Protoplast transactivation assays showed that ASR5 is able to recognize binding sites upstream of the MIR167a gene and drive its expression in vivo. Together, our data establish a comparative study of miRNAome profiles and is the first study to suggest the involvement of ASR proteins in miRNA gene regulation.

Physiological and Transcriptomic Responses of Chinese Cabbage (Brassica rapa L. ssp. Pekinensis) to Salt Stress

PubMed Central

Gao, Jianwei

2017-01-01

Salt stress is one of the major abiotic stresses that severely impact plant growth and development. In this study, we investigated the physiological and transcriptomic responses of Chinese cabbage “Qingmaye” to salt stress, a main variety in North China. Our results showed that the growth and photosynthesis of Chinese cabbage were significantly inhibited by salt treatment. However, as a glycophyte, Chinese cabbage could cope with high salinity; it could complete an entire life cycle at 100 mM NaCl. The high salt tolerance of Chinese cabbage was achieved by accumulating osmoprotectants and by maintaining higher activity of antioxidant enzymes. Transcriptomic responses were analyzed using the digital gene expression profiling (DGE) technique after 12 h of treatment by 200 mM NaCl. A total of 1235 differentially expressed genes (DEGs) including 740 up- and 495 down-regulated genes were identified. Functional annotation analyses showed that the DEGs were related to signal transduction, osmolyte synthesis, transcription factors, and antioxidant proteins. Taken together, this study contributes to our understanding of the mechanism of salt tolerance in Chinese cabbage and provides valuable information for further improvement of salt tolerance in Chinese cabbage breeding programs. PMID:28895882

An Approach to Function Annotation for Proteins of Unknown Function (PUFs) in the Transcriptome of Indian Mulberry.

PubMed

Dhanyalakshmi, K H; Naika, Mahantesha B N; Sajeevan, R S; Mathew, Oommen K; Shafi, K Mohamed; Sowdhamini, Ramanathan; N Nataraja, Karaba

2016-01-01

The modern sequencing technologies are generating large volumes of information at the transcriptome and genome level. Translation of this information into a biological meaning is far behind the race due to which a significant portion of proteins discovered remain as proteins of unknown function (PUFs). Attempts to uncover the functional significance of PUFs are limited due to lack of easy and high throughput functional annotation tools. Here, we report an approach to assign putative functions to PUFs, identified in the transcriptome of mulberry, a perennial tree commonly cultivated as host of silkworm. We utilized the mulberry PUFs generated from leaf tissues exposed to drought stress at whole plant level. A sequence and structure based computational analysis predicted the probable function of the PUFs. For rapid and easy annotation of PUFs, we developed an automated pipeline by integrating diverse bioinformatics tools, designated as PUFs Annotation Server (PUFAS), which also provides a web service API (Application Programming Interface) for a large-scale analysis up to a genome. The expression analysis of three selected PUFs annotated by the pipeline revealed abiotic stress responsiveness of the genes, and hence their potential role in stress acclimation pathways. The automated pipeline developed here could be extended to assign functions to PUFs from any organism in general. PUFAS web server is available at http://caps.ncbs.res.in/pufas/ and the web service is accessible at http://capservices.ncbs.res.in/help/pufas.

A Transcriptomic Network Underlies Microstructural and Physiological Responses to Cadmium in Populus × canescens1[C][W

PubMed Central

He, Jiali; Li, Hong; Luo, Jie; Ma, Chaofeng; Li, Shaojun; Qu, Long; Gai, Ying; Jiang, Xiangning; Janz, Dennis; Polle, Andrea; Tyree, Melvin; Luo, Zhi-Bin

2013-01-01

Bark tissue of Populus × canescens can hyperaccumulate cadmium, but microstructural, transcriptomic, and physiological response mechanisms are poorly understood. Histochemical assays, transmission electron microscopic observations, energy-dispersive x-ray microanalysis, and transcriptomic and physiological analyses have been performed to enhance our understanding of cadmium accumulation and detoxification in P. × canescens. Cadmium was allocated to the phloem of the bark, and subcellular cadmium compartmentalization occurred mainly in vacuoles of phloem cells. Transcripts involved in microstructural alteration, changes in nutrition and primary metabolism, and stimulation of stress responses showed significantly differential expression in the bark of P. × canescens exposed to cadmium. About 48% of the differentially regulated transcripts formed a coregulation network in which 43 hub genes played a central role both in cross talk among distinct biological processes and in coordinating the transcriptomic regulation in the bark of P. × canescens in response to cadmium. The cadmium transcriptome in the bark of P. × canescens was mirrored by physiological readouts. Cadmium accumulation led to decreased total nitrogen, phosphorus, and calcium and increased sulfur in the bark. Cadmium inhibited photosynthesis, resulting in decreased carbohydrate levels. Cadmium induced oxidative stress and antioxidants, including free proline, soluble phenolics, ascorbate, and thiol compounds. These results suggest that orchestrated microstructural, transcriptomic, and physiological regulation may sustain cadmium hyperaccumulation in P. × canescens bark and provide new insights into engineering woody plants for phytoremediation. PMID:23530184

Transcriptome Analysis of Portunus trituberculatus in Response to Salinity Stress Provides Insights into the Molecular Basis of Osmoregulation

PubMed Central

Lv, Jianjian; Liu, Ping; Wang, Yu; Gao, Baoquan; Chen, Ping; Li, Jian

2013-01-01

Background The swimming crab, Portunus trituberculatus, which is naturally distributed in the coastal waters of Asia-Pacific countries, is an important farmed species in China. Salinity is one of the most important abiotic factors that influence not only the distribution and abundance of crustaceans, it is also an important factor for artificial propagation of the crab. To better understand the interaction between salinity stress and osmoregulation, we performed a transcriptome analysis in the gills of Portunus trituberculatus challenged with salinity stress, using the Illumina Deep Sequencing technology. Results We obtained 27,696,835, 28,268,353 and 33,901,271 qualified Illumina read pairs from low salinity challenged (LC), non-challenged (NC), and high salinity challenged (HC) Portunus trituberculatus cDNA libraries, respectively. The overall de novo assembly of cDNA sequence data generated 94,511 unigenes, with an average length of 644 bp. Comparative genomic analysis revealed that 1,705 genes differentially expressed in salinity stress compared to the controls, including 615 and 1,516 unigenes in NC vs LC and NC vs HC respectively. GO functional enrichment analysis results showed some differentially expressed genes were involved in crucial processes related to osmoregulation, such as ion transport processes, amino acid metabolism and synthesis processes, proteolysis process and chitin metabolic process. Conclusion This work represents the first report of the utilization of the next generation sequencing techniques for transcriptome analysis in Portunus trituberculatus and provides valuable information on salinity adaptation mechanism. Results reveal a substantial number of genes modified by salinity stress and a few important salinity acclimation pathways, which will serve as an invaluable resource for revealing the molecular basis of osmoregulation in Portunus trituberculatus. In addition, the most comprehensive sequences of transcripts reported in this study provide a rich source for identification of novel genes in the crab. PMID:24312639

A comparison of the transcriptome of Drosophila melanogaster in response to entomopathogenic fungus, ionizing radiation, starvation and cold shock

PubMed Central

2015-01-01

Background The molecular mechanisms that determine the organism's response to a variety of doses and modalities of stress factors are not well understood. Results We studied effects of ionizing radiation (144, 360 and 864 Gy), entomopathogenic fungus (10 and 100 CFU), starvation (16 h), and cold shock (+4, 0 and -4°C) on an organism's viability indicators (survival and locomotor activity) and transcriptome changes in the Drosophila melanogaster model. All stress factors but cold shock resulted in a decrease of lifespan proportional to the dose of treatment. However, stress-factors affected locomotor activity without correlation with lifespan. Our data revealed both significant similarities and differences in differential gene expression and the activity of biological processes under the influence of stress factors. Conclusions Studied doses of stress treatments deleteriously affect the organism's viability and lead to different changes of both general and specific cellular stress response mechanisms. PMID:26694630

Heterologous oligonucleotide microarrays for transcriptomics in a non-model species; a proof-of-concept study of drought stress in Musa

PubMed Central

Davey, Mark W; Graham, Neil S; Vanholme, Bartel; Swennen, Rony; May, Sean T; Keulemans, Johan

2009-01-01

Background 'Systems-wide' approaches such as microarray RNA-profiling are ideally suited to the study of the complex overlapping responses of plants to biotic and abiotic stresses. However, commercial microarrays are only available for a limited number of plant species and development costs are so substantial as to be prohibitive for most research groups. Here we evaluate the use of cross-hybridisation to Affymetrix oligonucleotide GeneChip® microarrays to profile the response of the banana (Musa spp.) leaf transcriptome to drought stress using a genomic DNA (gDNA)-based probe-selection strategy to improve the efficiency of detection of differentially expressed Musa transcripts. Results Following cross-hybridisation of Musa gDNA to the Rice GeneChip® Genome Array, ~33,700 gene-specific probe-sets had a sufficiently high degree of homology to be retained for transcriptomic analyses. In a proof-of-concept approach, pooled RNA representing a single biological replicate of control and drought stressed leaves of the Musa cultivar 'Cachaco' were hybridised to the Affymetrix Rice Genome Array. A total of 2,910 Musa gene homologues with a >2-fold difference in expression levels were subsequently identified. These drought-responsive transcripts included many functional classes associated with plant biotic and abiotic stress responses, as well as a range of regulatory genes known to be involved in coordinating abiotic stress responses. This latter group included members of the ERF, DREB, MYB, bZIP and bHLH transcription factor families. Fifty-two of these drought-sensitive Musa transcripts were homologous to genes underlying QTLs for drought and cold tolerance in rice, including in 2 instances QTLs associated with a single underlying gene. The list of drought-responsive transcripts also included genes identified in publicly-available comparative transcriptomics experiments. Conclusion Our results demonstrate that despite the general paucity of nucleotide sequence data in Musa and only distant phylogenetic relations to rice, gDNA probe-based cross-hybridisation to the Rice GeneChip® is a highly promising strategy to study complex biological responses and illustrates the potential of such strategies for gene discovery in non-model species. PMID:19758430

A genome-wide transcriptome map of pistachio (Pistacia vera L.) provides novel insights into salinity-related genes and marker discovery.

PubMed

Moazzzam Jazi, Maryam; Seyedi, Seyed Mahdi; Ebrahimie, Esmaeil; Ebrahimi, Mansour; De Moro, Gianluca; Botanga, Christopher

2017-08-17

Pistachio (Pistacia vera L.) is one of the most important commercial nut crops worldwide. It is a salt-tolerant and long-lived tree, with the largest cultivation area in Iran. Climate change and subsequent increased soil salt content have adversely affected the pistachio yield in recent years. However, the lack of genomic/global transcriptomic sequences on P. vera impedes comprehensive researches at the molecular level. Hence, whole transcriptome sequencing is required to gain insight into functional genes and pathways in response to salt stress. RNA sequencing of a pooled sample representing 24 different tissues of two pistachio cultivars with contrasting salinity tolerance under control and salt treatment by Illumina Hiseq 2000 platform resulted in 368,953,262 clean 100 bp paired-ends reads (90 Gb). Following creating several assemblies and assessing their quality from multiple perspectives, we found that using the annotation-based metrics together with the length-based parameters allows an improved assessment of the transcriptome assembly quality, compared to the solely use of the length-based parameters. The generated assembly by Trinity was adopted for functional annotation and subsequent analyses. In total, 29,119 contigs annotated against all of five public databases, including NR, UniProt, TAIR10, KOG and InterProScan. Among 279 KEGG pathways supported by our assembly, we further examined the pathways involved in the plant hormone biosynthesis and signaling as well as those to be contributed to secondary metabolite biosynthesis due to their importance under salinity stress. In total, 11,337 SSRs were also identified, which the most abundant being dinucleotide repeats. Besides, 13,097 transcripts as candidate stress-responsive genes were identified. Expression of some of these genes experimentally validated through quantitative real-time PCR (qRT-PCR) that further confirmed the accuracy of the assembly. From this analysis, the contrasting expression pattern of NCED3 and SOS1 genes were observed between salt-sensitive and salt-tolerant cultivars. This study, as the first report on the whole transcriptome survey of P. vera, provides important resources and paves the way for functional and comparative genomic studies on this major tree to discover the salinity tolerance-related markers and stress response mechanisms for breeding of new pistachio cultivars with more salinity tolerance.

Investigating the Responses of Cronobacter sakazakii to Garlic-Drived Organosulfur Compounds: a Systematic Study of Pathogenic-Bacterium Injury by Use of High-Throughput Whole-Transcriptome Sequencing and Confocal Micro-Raman Spectroscopy

PubMed Central

Feng, Shaolong; Eucker, Tyson P.; Holly, Mayumi K.; Konkel, Michael E.

2014-01-01

We present the results of a study using high-throughput whole-transcriptome sequencing (RNA-seq) and vibrational spectroscopy to characterize and fingerprint pathogenic-bacterium injury under conditions of unfavorable stress. Two garlic-derived organosulfur compounds were found to be highly effective antimicrobial compounds against Cronobacter sakazakii, a leading pathogen associated with invasive infection of infants and causing meningitis, necrotizing entercolitis, and bacteremia. RNA-seq shows changes in gene expression patterns and transcriptomic response, while confocal micro-Raman spectroscopy characterizes macromolecular changes in the bacterial cell resulting from this chemical stress. RNA-seq analyses showed that the bacterial response to ajoene differed from the response to diallyl sulfide. Specifically, ajoene caused downregulation of motility-related genes, while diallyl sulfide treatment caused an increased expression of cell wall synthesis genes. Confocal micro-Raman spectroscopy revealed that the two compounds appear to have the same phase I antimicrobial mechanism of binding to thiol-containing proteins/enzymes in bacterial cells generating a disulfide stretching band but different phase II antimicrobial mechanisms, showing alterations in the secondary structures of proteins in two different ways. Diallyl sulfide primarily altered the α-helix and β-sheet, as reflected in changes in amide I, while ajoene altered the structures containing phenylalanine and tyrosine. Bayesian probability analysis validated the ability of principal component analysis to differentiate treated and control C. sakazakii cells. Scanning electron microscopy confirmed cell injury, showing significant morphological variations in cells following treatments by these two compounds. Findings from this study aid in the development of effective intervention strategies to reduce the risk of C. sakazakii contamination in the food production environment and on food contact surfaces, reducing the risks to susceptible consumers. PMID:24271174

Monitoring Transcriptomic Changes in Soil-Grown Roots and Shoots of Arabidopsis thaliana Subjected to a Progressive Drought Stress.

PubMed

Bashir, Khurram; Rasheed, Sultana; Matsui, Akihiro; Iida, Kei; Tanaka, Maho; Seki, Motoaki

2018-01-01

Numerous experiments have been performed in Arabidopsis to monitor changes in gene expression that occur in response to a variety of abiotic and biotic stresses, different growth conditions, and at various developmental stages. In addition, gene expression patterns have also been characterized among wild-type and mutant genotypes. Despite these numerous reports, transcriptional changes occurring in roots of soil-grown plants subjected to a progressive drought stress have remained undocumented. To fill this gap, we established a system that allows one to establish water-deficit conditions and to collect root and shoot samples with minimal damage to the root system. Arabidopsis plants are grown in a ceramic-based granular soil and subjected to progressive drought stress by withholding water. Root and shoot samples were collected separately, RNA was purified, and a microarray analysis of drought-stressed roots and shoots was performed at 0, 1, 3, 5, 7, and 9 days after the onset of drought stress treatment. Here, we describe the detailed protocol used to analyze the transcriptomic changes occurring in roots and shoots of soil-grown Arabidopsis subjected to a progressive drought stress.

De Novo assembly of expressed transcripts and global transcriptomic analysis from seedlings of the paper mulberry (Broussonetia kazinoki x Broussonetia papyifera).

PubMed

Xianjun, Peng; Linhong, Teng; Xiaoman, Wang; Yucheng, Wang; Shihua, Shen

2014-01-01

The paper mulberry is one of the multifunctional tree species in agroforestry systems and is also commonly utilized in traditional medicine in China and other Asian countries. However, little is known about its molecular genetics, which hinders research on and exploitation of this valuable resource. To discern the correlation between gene expression and the essential properties of the paper mulberry, we performed a transcriptomics analysis, assembling a total of 37,725 unigenes from 54,638,676 reads generated by RNA-seq. Among these, 22,692 unigenes showed greater than 60% similarity with genes from other species. The lengths of 13,566 annotated unigenes were longer than 1,000 bp. Functional clustering analysis with COG (Cluster of Orthologous Groups) revealed that 17,184 unigenes are primarily involved in transcription, translation, signal transduction, carbohydrate metabolism, secondary metabolism, and energy metabolism. GO (Gene Ontology) annotation suggests enrichment of genes encoding antioxidant activity, transporter activity, biosynthesis, metabolism and stress response, with a total of 30,659 unigenes falling in these categories. KEGG (Kyoto Encyclopedia of Genes and Genomes) metabolic pathway analysis showed that 7,199 unigenes are associated with 119 metabolic pathways. In addition to the basic metabolism, these genes are enriched for plant pathogen interaction, flavonoid metabolism and other secondary metabolic processes. Furthermore, differences in the transcriptomes of leaf, stem and root tissues were analyzed and 7,233 specifically expressed unigenes were identified. This global expression analysis provided novel insights about the molecular mechanisms of the biosynthesis of flavonoid, lignin and cellulose, as well as on the response to biotic and abiotic stresses including the remediation of contaminated soil by the paper mulberry.

Response to Long-Term NaHCO3-Derived Alkalinity in Model Lotus japonicus Ecotypes Gifu B-129 and Miyakojima MG-20: Transcriptomic Profiling and Physiological Characterization

PubMed Central

Rocco, Rubén; Bordenave, Cesar D.; Escaray, Francisco J.; Antonelli, Cristian; Calzadilla, Pablo; Gárriz, Andrés; Serna, Eva; Carrasco, Pedro; Menendez, Ana B.

2014-01-01

The current knowledge regarding transcriptomic changes induced by alkalinity on plants is scarce and limited to studies where plants were subjected to the alkaline salt for periods not longer than 48 h, so there is no information available regarding the regulation of genes involved in the generation of a new homeostatic cellular condition after long-term alkaline stress. Lotus japonicus is a model legume broadly used to study many important physiological processes including biotic interactions and biotic and abiotic stresses. In the present study, we characterized phenotipically the response to alkaline stress of the most widely used L. japonicus ecotypes, Gifu B-129 and MG-20, and analyzed global transcriptome of plants subjected to 10 mM NaHCO3 during 21 days, by using the Affymetrix Lotus japonicus GeneChip®. Plant growth assessment, gas exchange parameters, chlorophyll a fluorescence transient (OJIP) analysis and metal accumulation supported the notion that MG-20 plants displayed a higher tolerance level to alkaline stress than Gifu B-129. Overall, 407 and 459 probe sets were regulated in MG-20 and Gifu B-129, respectively. The number of probe sets differentially expressed in roots was higher than that of shoots, regardless the ecotype. Gifu B-129 and MG-20 also differed in their regulation of genes that could play important roles in the generation of a new Fe/Zn homeostatic cellular condition, synthesis of plant compounds involved in stress response, protein-degradation, damage repair and root senescence, as well as in glycolysis, gluconeogenesis and TCA. In addition, there were differences between both ecotypes in the expression patterns of putative transcription factors that could determine distinct arrangements of flavonoid and isoflavonoid compounds. Our results provided a set of selected, differentially expressed genes deserving further investigation and suggested that the L. japonicus ecotypes could constitute a useful model to search for common and distinct tolerance mechanisms to long-term alkaline stress response in plants. PMID:24835559

Transcriptomic Analysis of Metabolic Pathways in Milkfish That Respond to Salinity and Temperature Changes.

PubMed

Hu, Yau-Chung; Kang, Chao-Kai; Tang, Cheng-Hao; Lee, Tsung-Han

2015-01-01

Milkfish (Chanos chanos), an important marine aquaculture species in southern Taiwan, show considerable euryhalinity but have low tolerance to sudden drops in water temperatures in winter. Here, we used high throughput next-generation sequencing (NGS) to identify molecular and biological processes involved in the responses to environmental changes. Preliminary tests revealed that seawater (SW)-acclimated milkfish tolerated lower temperatures than the fresh water (FW)-acclimated group. Although FW- and SW-acclimated milkfish have different levels of tolerance for hypothermal stress, to date, the molecular physiological basis of this difference has not been elucidated. Here, we performed a next-generation sequence analysis of mRNAs from four groups of milkfish. We obtained 29669 unigenes with an average length of approximately 1936 base pairs. Gene ontology (GO) analysis was performed after gene annotation. A large number of genes for molecular regulation were identified through a transcriptomic comparison in a KEGG analysis. Basal metabolic pathways involved in hypothermal tolerance, such as glycolysis, fatty acid metabolism, amino acid catabolism and oxidative phosphorylation, were analyzed using PathVisio and Cytoscape software. Our results indicate that in response to hypothermal stress, genes for oxidative phosphorylation, e.g., succinate dehydrogenase, were more highly up-regulated in SW than FW fish. Moreover, SW and FW milkfish used different strategies when exposed to hypothermal stress: SW milkfish up-regulated oxidative phosphorylation and catabolism genes to produce more energy budget, whereas FW milkfish down-regulated genes related to basal metabolism to reduce energy loss.

Transcriptomic Analysis of Metabolic Pathways in Milkfish That Respond to Salinity and Temperature Changes

PubMed Central

Hu, Yau-Chung; Kang, Chao-Kai; Tang, Cheng-Hao; Lee, Tsung-Han

2015-01-01

Milkfish (Chanos chanos), an important marine aquaculture species in southern Taiwan, show considerable euryhalinity but have low tolerance to sudden drops in water temperatures in winter. Here, we used high throughput next-generation sequencing (NGS) to identify molecular and biological processes involved in the responses to environmental changes. Preliminary tests revealed that seawater (SW)-acclimated milkfish tolerated lower temperatures than the fresh water (FW)-acclimated group. Although FW- and SW-acclimated milkfish have different levels of tolerance for hypothermal stress, to date, the molecular physiological basis of this difference has not been elucidated. Here, we performed a next-generation sequence analysis of mRNAs from four groups of milkfish. We obtained 29669 unigenes with an average length of approximately 1936 base pairs. Gene ontology (GO) analysis was performed after gene annotation. A large number of genes for molecular regulation were identified through a transcriptomic comparison in a KEGG analysis. Basal metabolic pathways involved in hypothermal tolerance, such as glycolysis, fatty acid metabolism, amino acid catabolism and oxidative phosphorylation, were analyzed using PathVisio and Cytoscape software. Our results indicate that in response to hypothermal stress, genes for oxidative phosphorylation, e.g., succinate dehydrogenase, were more highly up-regulated in SW than FW fish. Moreover, SW and FW milkfish used different strategies when exposed to hypothermal stress: SW milkfish up-regulated oxidative phosphorylation and catabolism genes to produce more energy budget, whereas FW milkfish down-regulated genes related to basal metabolism to reduce energy loss. PMID:26263550

Gene regulation network behind drought escape, avoidance and tolerance strategies in black poplar (Populus nigra L.).

PubMed

Yıldırım, Kubilay; Kaya, Zeki

2017-06-01

Drought is the major environmental problem limiting the productivity and survival of plant species. Here, previously identified three black poplar genotypes having contrasting response to drought were subjected to gradual soil water depletion in a pot trial to identify their physiological, morphological and antioxidation related adaptations. We also performed a microarray based transcriptome analyses on the leaves of genotypes by using Affymetrix poplar Genome Array containing 56,000 transcripts. Phenotypic analyses of each genotype confirmed their differential adaptations to drought that could be classified as drought escape, avoidance and tolerance. Comparative transcriptomic analysis indicated highly divergent gene expression patterns among the genotypes in response to drought and post drought re-watering (PDR). We identified 10641, 3824 and 9411 transcripts exclusively regulated in drought escape, avoidance and tolerant genotypes, respectively. The key genes involved in metabolic pathways, such as carbohydrate metabolism, photosynthesis, lipid metabolism, generation of precursor metabolites/energy, protein folding, redox homeostasis, secondary metabolic process and cell wall component biogenesis, were affected by drought stresses in the leaves of these genotypes. Transcript isoforms showed increased expression specificity in the genes coding for bark storage proteins and small heat shock proteins in drought tolerant genotype. On the other hand, drought-avoiding genotype specifically induced the transcripts annotated to the genes functional in secondary metabolite production that linked to enhanced leaf water content and growth performance under drought stress. Transcriptome profiling of drought escape genotype indicated specific regulation of the genes functional in programmed cell death and leaf senescence. Specific upregulation of GTP cyclohydrolase II and transcription factors (WRKY and ERFs) in only this genotype were associated to ROS dependent signalling pathways and gene regulation network responsible in induction of many degrading enzymes acting on cell wall carbohydrates, fatty acids and proteins under drought stress. Our findings provide new insights into the transcriptome dynamics and components of regulatory network associated with drought adaptation strategies. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Transcriptome-wide identification of salt-responsive members of the WRKY gene family in Gossypium aridum.

PubMed

Fan, Xinqi; Guo, Qi; Xu, Peng; Gong, YuanYong; Shu, Hongmei; Yang, Yang; Ni, Wanchao; Zhang, Xianggui; Shen, Xinlian

2015-01-01

WRKY transcription factors are plant-specific, zinc finger-type transcription factors. The WRKY superfamily is involved in abiotic stress responses in many crops including cotton, a major fiber crop that is widely cultivated and consumed throughout the world. Salinity is an important abiotic stress that results in considerable yield losses. In this study, we identified 109 WRKY genes (GarWRKYs) in a salt-tolerant wild cotton species Gossypium aridum from transcriptome sequencing data to elucidate the roles of these factors in cotton salt tolerance. According to their structural features, the predicted members were divided into three groups (Groups I-III), as previously described for Arabidopsis. Furthermore, 28 salt-responsive GarWRKY genes were identified from digital gene expression data and subjected to real-time quantitative RT-PCR analysis. The expression patterns of most GarWRKY genes revealed by this analysis are in good agreement with those revealed by RNA-Seq analysis. RT-PCR analysis revealed that 27 GarWRKY genes were expressed in roots and one was exclusively expressed in roots. Analysis of gene orthology and motif compositions indicated that WRKY members from Arabidopsis, rice and soybean generally shared the similar motifs within the same subgroup, suggesting they have the similar function. Overexpression-GarWRKY17 and -GarWRKY104 in Arabidopsis revealed that they could positively regulate salt tolerance of transgenic Arabidopsis during different development stages. The comprehensive data generated in this study provide a platform for elucidating the functions of WRKY transcription factors in salt tolerance of G. aridum. In addition, GarWRKYs related to salt tolerance identified in this study will be potential candidates for genetic improvement of cultivated cotton salt stress tolerance.

Deep Transcriptomic Analysis of Black Rockfish (Sebastes schlegelii) Provides New Insights on Responses to Acute Temperature Stress.

PubMed

Lyu, Likang; Wen, Haishen; Li, Yun; Li, Jifang; Zhao, Ji; Zhang, Simin; Song, Min; Wang, Xiaojie

2018-06-14

In the present study, we conducted an RNA-Seq analysis to characterize the genes and pathways involved in acute thermal and cold stress responses in the liver of black rockfish, a viviparous teleost that has the ability to cope with a wide range of temperature changes. A total of 584 annotated differentially expressed genes (DEGs) were identified in all three comparisons (HT vs NT, HT vs LT and LT vs NT). Based on an enrichment analysis, DEGs with a potential role in stress accommodation were classified into several categories, including protein folding, metabolism, immune response, signal transduction, molecule transport, membrane, and cell proliferation/apoptosis. Considering that thermal stress has a greater effect than cold stress in black rockfish, 24 shared DEGs in the intersection of the HT vs LT and HT vs NT groups were enriched in 2 oxidation-related gene ontology (GO) terms. Nine important heat-stress-reducing pathways were significantly identified and classified into 3 classes: immune and infectious diseases, organismal immune system and endocrine system. Eight DEGs (early growth response protein 1, bile salt export pump, abcb11, hsp70a, rtp3, 1,25-dihydroxyvitamin d(3) 24-hydroxylase, apoa4, transcription factor jun-b-like and an uncharacterized gene) were observed among all three comparisons, strongly implying their potentially important roles in temperature stress responses.

Dynamics of the Saccharomyces cerevisiae Transcriptome during Bread Dough Fermentation

PubMed Central

Aslankoohi, Elham; Zhu, Bo; Rezaei, Mohammad Naser; Voordeckers, Karin; De Maeyer, Dries; Marchal, Kathleen; Dornez, Emmie

2013-01-01

The behavior of yeast cells during industrial processes such as the production of beer, wine, and bioethanol has been extensively studied. In contrast, our knowledge about yeast physiology during solid-state processes, such as bread dough, cheese, or cocoa fermentation, remains limited. We investigated changes in the transcriptomes of three genetically distinct Saccharomyces cerevisiae strains during bread dough fermentation. Our results show that regardless of the genetic background, all three strains exhibit similar changes in expression patterns. At the onset of fermentation, expression of glucose-regulated genes changes dramatically, and the osmotic stress response is activated. The middle fermentation phase is characterized by the induction of genes involved in amino acid metabolism. Finally, at the latest time point, cells suffer from nutrient depletion and activate pathways associated with starvation and stress responses. Further analysis shows that genes regulated by the high-osmolarity glycerol (HOG) pathway, the major pathway involved in the response to osmotic stress and glycerol homeostasis, are among the most differentially expressed genes at the onset of fermentation. More importantly, deletion of HOG1 and other genes of this pathway significantly reduces the fermentation capacity. Together, our results demonstrate that cells embedded in a solid matrix such as bread dough suffer severe osmotic stress and that a proper induction of the HOG pathway is critical for optimal fermentation. PMID:24056467

Transcriptomic changes during maize roots development responsive to Cadmium (Cd) pollution using comparative RNAseq-based approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peng, Hua; Sichuan Tourism College, Chengdu, 610000, Sichuan; He, Xiujing

The heavy metal cadmium (Cd), acts as a widespread environmental contaminant, which has shown to adversely affect human health, food safety and ecosystem safety in recent years. However, research on how plant respond to various kinds of heavy metal stress is scarcely reported, especially for understanding of complex molecular regulatory mechanisms and elucidating the gene networks of plant respond to Cd stress. Here, transcriptomic changes during Mo17 and B73 seedlings development responsive to Cd pollution were investigated and comparative RNAseq-based approach in both genotypes were performed. 115 differential expression genes (DEGs) with significant alteration in expression were found co-modulated inmore » both genotypes during the maize seedling development; of those, most of DGEs were found comprised of stress and defense responses proteins, transporters, as well as transcription factors, such as thaumatin-like protein, ZmOPR2 and ZmOPR5. More interestingly, genotype-specific transcriptional factors changes induced by Cd stress were found contributed to the regulatory mechanism of Cd sensitivity in both different genotypes. Moreover, 12 co-expression modules associated with specific biological processes or pathways (M1 to M12) were identified by consensus co-expression network. These results will expand our understanding of complex molecular mechanism of response and defense to Cd exposure in maize seedling roots. - Highlights: • Transcriptomic changes responsive to Cd pollution using comparative RNAseq-based approach. • 115 differential expression genes (DEGs) were found co-modulated in both genotypes. • Most of DGEs belong to stress and defense responses proteins, transporters, transcription factors. • 12 co-expression modules associated with specific biological processes or pathways. • Genotype-specific transcriptional factors changes induced by Cd stress were found.« less

RNA-seq Analysis of Cold and Drought Responsive Transcriptomes of Zea mays ssp. mexicana L.

PubMed

Lu, Xiang; Zhou, Xuan; Cao, Yu; Zhou, Meixue; McNeil, David; Liang, Shan; Yang, Chengwei

2017-01-01

The annual Zea mays ssp. mexicana L. is a member of teosinte, a wild relative of the Zea mays spp. mays L. This subspecies has strong growth and regeneration ability, high tiller numbers, high protein and lysine content as well as resistance to many fungal diseases, and it can be effectively used in maize improvement. In this study, we reported a Zea mays ssp. mexicana L. transcriptome by merging data from untreated control (CK), cold (4°C) and drought (PEG2000, 20%) treated plant samples. A total of 251,145 transcripts (N50 = 1,269 bp) and 184,280 unigenes (N50 = 923 bp) were predicted, which code for homologs of near 47% of the published maize proteome. Under cold conditions, 2,232 and 817 genes were up-regulated and down-regulated, respectively, while fewer genes were up-regulated (532) and down-regulated (82) under drought stress, indicating that Zea mays ssp. mexicana L. is more sensitive to the applied cold rather than to the applied drought stresses. Functional enrichment analyses identified many common or specific biological processes and gene sets in response to drought and cold stresses. The ABA dependent pathway, trehalose synthetic pathway and the ICE1-CBF pathway were up-regulated by both stresses. GA associated genes have been shown to differentially regulate the responses to cold in close subspecies in Zea mays . These findings and the identified functional genes can provide useful clues for improving abiotic stress tolerance of maize.

RNA-seq Analysis of Cold and Drought Responsive Transcriptomes of Zea mays ssp. mexicana L.

PubMed Central

Lu, Xiang; Zhou, Xuan; Cao, Yu; Zhou, Meixue; McNeil, David; Liang, Shan; Yang, Chengwei

2017-01-01

The annual Zea mays ssp. mexicana L. is a member of teosinte, a wild relative of the Zea mays spp. mays L. This subspecies has strong growth and regeneration ability, high tiller numbers, high protein and lysine content as well as resistance to many fungal diseases, and it can be effectively used in maize improvement. In this study, we reported a Zea mays ssp. mexicana L. transcriptome by merging data from untreated control (CK), cold (4°C) and drought (PEG2000, 20%) treated plant samples. A total of 251,145 transcripts (N50 = 1,269 bp) and 184,280 unigenes (N50 = 923 bp) were predicted, which code for homologs of near 47% of the published maize proteome. Under cold conditions, 2,232 and 817 genes were up-regulated and down-regulated, respectively, while fewer genes were up-regulated (532) and down-regulated (82) under drought stress, indicating that Zea mays ssp. mexicana L. is more sensitive to the applied cold rather than to the applied drought stresses. Functional enrichment analyses identified many common or specific biological processes and gene sets in response to drought and cold stresses. The ABA dependent pathway, trehalose synthetic pathway and the ICE1-CBF pathway were up-regulated by both stresses. GA associated genes have been shown to differentially regulate the responses to cold in close subspecies in Zea mays. These findings and the identified functional genes can provide useful clues for improving abiotic stress tolerance of maize. PMID:28223998

Transcriptomic and physiological analyses of Medicago sativa L. roots in response to lead stress

PubMed Central

Zhang, Shichao; Guo, Qiang; Jin, Yan; Chen, Jingjing; Ma, Hongxia

2017-01-01

Lead (Pb) is one of the nonessential and toxic metals that threaten the environment and human health. Medicago sativa L. is a legume with high salt tolerance and high biomass production. It is not only a globally important forage crop but is also an ideal plant for phytoremediation. However, the biological and molecular mechanisms that respond to heavy metals are still not well defined in M. sativa. In this study, de novo and strand-specific RNA-sequencing was performed to identify genes involved in the Pb stress response in M. sativa roots. A total of 415,350 unigenes were obtained from the assembled cDNA libraries, among which 5,416 were identified as significantly differentially expressed genes (DEGs) (false discovery rate < 0.005) between cDNA libraries from control and Pb-treated plants. Gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of the DEGs showed they mainly clustered with terms associated with binding, transport, membranes, and the pathways related to signal and energy metabolism. Moreover, a number of candidate genes included antioxidant enzymes, metal transporters, and transcription factors involved in heavy metal response were upregulated under Pb stress. Quantitative real-time PCR(qRT-PCR) validation of the expression patterns of 10 randomly selected candidate DEGs were consistent with the transcriptome analysis results. Thus, this study offers new information towards the investigation of biological changes and molecular mechanisms related to Pb stress response in plants. PMID:28388670

Transcriptome Response to Embolism Formation in Stems of Populus trichocarpa Provides Insight into Signaling and the Biology of Refilling1[W][OA

PubMed Central

Secchi, Francesca; Gilbert, Matthew E.; Zwieniecki, Maciej A.

2011-01-01

The mechanism of embolism repair in transpiring plants is still not understood, despite significant scientific effort. The refilling process is crucial to maintaining stem transport capacity and ensuring survival for plants experiencing dynamic changes in water stress. Refilling air-filled xylem vessels requires an energy and water source that can only be provided by adjacent living parenchyma cells. Here, we report an analysis of the transcriptome response of xylem parenchyma cells after embolism formation in Populus trichocarpa trees. Genes encoding aquaporins, ion transporters, and carbohydrate metabolic pathways were up-regulated, and there was a significant reduction in the expression of genes responding to oxidative stress. Thus, a novel view of the plant response to embolism emerges that suggests a role for oxygen in embolized vessels as a signal triggering xylem refilling and for the activity of cation transport as having a significant role in the generation of the energy gradient necessary to heal embolized vessels. These findings redefine current hypotheses surrounding the refilling phenomenon and provide insight into the complexity of the biological response to the seemingly simple physical event of xylem embolism formation. PMID:21951466

Transcriptome Analysis of the Hepatopancreas in the Pacific White Shrimp (Litopenaeus vannamei) under Acute Ammonia Stress

PubMed Central

Lu, Xia; Kong, Jie; Luan, Sheng; Dai, Ping; Meng, Xianhong; Cao, Baoxiang; Luo, Kun

2016-01-01

In the practical farming of Litopenaeus vannamei, the intensive culture system and environmental pollution usually results in a high concentration of ammonia, which usually brings large detrimental effects to shrimp, such as increasing the susceptibility to pathogens, reducing growth, decreasing osmoregulatory capacity, increasing the molting frequency, and even causing high mortality. However, little information is available on the molecular mechanisms of the detrimental effects of ammonia stress in shrimp. In this study, we performed comparative transcriptome analysis between ammonia-challenged and control groups from the same family of L. vannamei to identify the key genes and pathways response to ammonia stress. The comparative transcriptome analysis identified 136 significantly differentially expressed genes that have high homologies with the known proteins in aquatic species, among which 94 genes are reported potentially related to immune function, and the rest of the genes are involved in apoptosis, growth, molting, and osmoregulation. Fourteen GO terms and 6 KEGG pathways were identified to be significantly changed by ammonia stress. In these GO terms, 13 genes have been studied in aquatic species, and 11 of them were reported potentially involved in immune defense and two genes were related to molting. In the significantly changed KEGG pathways, all the 7 significantly changed genes have been reported in shrimp, and four of them were potentially involved in immune defense and the other three were related to molting, defending toxicity, and osmoregulation, respectively. In addition, majority of the significantly changed genes involved in nitrogen metabolisms that play an important role in reducing ammonia toxicity failed to perform the protection function. The present results have supplied molecular level support for the previous founding of the detrimental effects of ammonia stress in shrimp, which is a prerequisite for better understanding the molecular mechanism of the immunosuppression from ammonia stress. PMID:27760162

Transcriptome Analysis of the Hepatopancreas in the Pacific White Shrimp (Litopenaeus vannamei) under Acute Ammonia Stress.

PubMed

Lu, Xia; Kong, Jie; Luan, Sheng; Dai, Ping; Meng, Xianhong; Cao, Baoxiang; Luo, Kun

2016-01-01

In the practical farming of Litopenaeus vannamei, the intensive culture system and environmental pollution usually results in a high concentration of ammonia, which usually brings large detrimental effects to shrimp, such as increasing the susceptibility to pathogens, reducing growth, decreasing osmoregulatory capacity, increasing the molting frequency, and even causing high mortality. However, little information is available on the molecular mechanisms of the detrimental effects of ammonia stress in shrimp. In this study, we performed comparative transcriptome analysis between ammonia-challenged and control groups from the same family of L. vannamei to identify the key genes and pathways response to ammonia stress. The comparative transcriptome analysis identified 136 significantly differentially expressed genes that have high homologies with the known proteins in aquatic species, among which 94 genes are reported potentially related to immune function, and the rest of the genes are involved in apoptosis, growth, molting, and osmoregulation. Fourteen GO terms and 6 KEGG pathways were identified to be significantly changed by ammonia stress. In these GO terms, 13 genes have been studied in aquatic species, and 11 of them were reported potentially involved in immune defense and two genes were related to molting. In the significantly changed KEGG pathways, all the 7 significantly changed genes have been reported in shrimp, and four of them were potentially involved in immune defense and the other three were related to molting, defending toxicity, and osmoregulation, respectively. In addition, majority of the significantly changed genes involved in nitrogen metabolisms that play an important role in reducing ammonia toxicity failed to perform the protection function. The present results have supplied molecular level support for the previous founding of the detrimental effects of ammonia stress in shrimp, which is a prerequisite for better understanding the molecular mechanism of the immunosuppression from ammonia stress.

Transcriptome analysis reveals that multidrug efflux genes are upregulated to protect Pseudomonas aeruginosa from pentachlorophenol stress.

PubMed

Muller, Jocelyn Fraga; Stevens, Ann M; Craig, Johanna; Love, Nancy G

2007-07-01

Through chemical contamination of natural environments, microbial communities are exposed to many different types of chemical stressors; however, research on whole-genome responses to this contaminant stress is limited. This study examined the transcriptome response of a common soil bacterium, Pseudomonas aeruginosa, to the common environmental contaminant pentachlorophenol (PCP). Cells were grown in chemostats at a low growth rate to obtain substrate-limited, steady-state, balanced-growth conditions. The PCP stress was administered as a continuous increase in concentration, and samples taken over time were examined for physiological function changes with whole-cell acetate uptake rates (WAURs) and cell viability and for gene expression changes by Affymetrix GeneChip technology and real-time reverse transcriptase PCR. Cell viability, measured by heterotrophic plate counts, showed a moderately steady decrease after exposure to the stressor, but WAURs did not change in response to PCP. In contrast to the physiological data, the microarray data showed significant changes in the expression of several genes. In particular, genes coding for multidrug efflux pumps, including MexAB-OprM, were strongly upregulated. The upregulation of these efflux pumps protected the cells from the potentially toxic effects of PCP, allowing the physiological whole-cell function to remain constant.

Comparative Analysis of Transcriptomes in Rhizophoraceae Provides Insights into the Origin and Adaptive Evolution of Mangrove Plants in Intertidal Environments.

PubMed

Guo, Wuxia; Wu, Haidan; Zhang, Zhang; Yang, Chao; Hu, Ling; Shi, Xianggang; Jian, Shuguang; Shi, Suhua; Huang, Yelin

2017-01-01

Mangroves are woody plants that grow at the interface between land and sea in tropical and subtropical latitudes, where they exist in conditions of high salinity, extreme tides, strong winds, high temperatures, and muddy, anaerobic soils. Rhizophoraceae is a key mangrove family, with highly developed morphological and physiological adaptations to extreme conditions. It is an ideal system for the study of the origin and adaptive evolution of mangrove plants. In this study, we characterized and comprehensively compared the transcriptomes of four mangrove species, from all four mangrove genera, as well as their closest terrestrial relative in Rhizophoraceae, using RNA-Seq. We obtained 41,936-48,845 unigenes with N50 values of 982-1,185 bp and 61.42-69.48% annotated for the five species in Rhizophoraceae. Orthology annotations of Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and Clusters of Orthologous Groups revealed overall similarities in the transcriptome profiles among the five species, whereas enrichment analysis identified remarkable genomic characteristics that are conserved across the four mangrove species but differ from their terrestrial relative. Based on 1,816 identified orthologs, phylogeny analysis and divergence time estimation revealed a single origin for mangrove species in Rhizophoraceae, which diverged from the terrestrial lineage ~56.4 million years ago (Mya), suggesting that the transgression during the Paleocene-Eocene Thermal Maximum may have been responsible for the entry of the mangrove lineage of Rhizophoraceae into intertidal environments. Evidence showed that the ancestor of Rhizophoraceae may have experienced a whole genome duplication event ~74.6 Mya, which may have increased the adaptability and survival chances of Rhizophoraceae during and following the Cretaceous-Tertiary extinction. The analysis of positive selection identified 10 positively selected genes from the ancestor branch of Rhizophoraceae mangroves, which were mainly associated with stress response, embryo development, and regulation of gene expression. Positive selection of these genes may be crucial for increasing the capability of stress tolerance (i.e., defense against salt and oxidative stress) and development of adaptive traits (i.e., vivipary) of Rhizophoraceae mangroves, and thus plays an important role in their adaptation to the stressful intertidal environments.

Comparative Analysis of Transcriptomes in Rhizophoraceae Provides Insights into the Origin and Adaptive Evolution of Mangrove Plants in Intertidal Environments

PubMed Central

Guo, Wuxia; Wu, Haidan; Zhang, Zhang; Yang, Chao; Hu, Ling; Shi, Xianggang; Jian, Shuguang; Shi, Suhua; Huang, Yelin

2017-01-01

Mangroves are woody plants that grow at the interface between land and sea in tropical and subtropical latitudes, where they exist in conditions of high salinity, extreme tides, strong winds, high temperatures, and muddy, anaerobic soils. Rhizophoraceae is a key mangrove family, with highly developed morphological and physiological adaptations to extreme conditions. It is an ideal system for the study of the origin and adaptive evolution of mangrove plants. In this study, we characterized and comprehensively compared the transcriptomes of four mangrove species, from all four mangrove genera, as well as their closest terrestrial relative in Rhizophoraceae, using RNA-Seq. We obtained 41,936–48,845 unigenes with N50 values of 982–1,185 bp and 61.42–69.48% annotated for the five species in Rhizophoraceae. Orthology annotations of Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and Clusters of Orthologous Groups revealed overall similarities in the transcriptome profiles among the five species, whereas enrichment analysis identified remarkable genomic characteristics that are conserved across the four mangrove species but differ from their terrestrial relative. Based on 1,816 identified orthologs, phylogeny analysis and divergence time estimation revealed a single origin for mangrove species in Rhizophoraceae, which diverged from the terrestrial lineage ~56.4 million years ago (Mya), suggesting that the transgression during the Paleocene–Eocene Thermal Maximum may have been responsible for the entry of the mangrove lineage of Rhizophoraceae into intertidal environments. Evidence showed that the ancestor of Rhizophoraceae may have experienced a whole genome duplication event ~74.6 Mya, which may have increased the adaptability and survival chances of Rhizophoraceae during and following the Cretaceous–Tertiary extinction. The analysis of positive selection identified 10 positively selected genes from the ancestor branch of Rhizophoraceae mangroves, which were mainly associated with stress response, embryo development, and regulation of gene expression. Positive selection of these genes may be crucial for increasing the capability of stress tolerance (i.e., defense against salt and oxidative stress) and development of adaptive traits (i.e., vivipary) of Rhizophoraceae mangroves, and thus plays an important role in their adaptation to the stressful intertidal environments. PMID:28559911

Rapid accumulation of glutathione during light stress in Arabidopsis.

PubMed

Choudhury, Feroza K; Devireddy, Amith R; Azad, Rajeev K; Shulaev, Vladimir; Mittler, Ron

2018-05-25

Environmental stress conditions can drastically affect plant growth and productivity. In contrast to soil moisture or salinity that can gradually change over a period of days or weeks, changes in light intensity or temperature can occur very rapidly, sometimes over the course of minutes or seconds. We previously reported that in response to rapid changes in light intensity (0-60 sec), Arabidopsis thaliana plants mount a large-scale transcriptomic response that includes several different transcripts essential for light stress acclimation. Here, we expand our analysis of the rapid response of Arabidopsis to light stress using a metabolomics approach and identify 111 metabolites that significantly alter in their level during the first 90 sec of light stress exposure. We further show that the levels of free and total glutathione accumulate rapidly during light stress in Arabidopsis and that the accumulation of total glutathione during light stress is associated with an increase in nitric oxide (NO) levels. We further suggest that the increase in precursors for glutathione biosynthesis could be linked to alterations in photorespiration, and that phosphoenolpyruvate could represent a major energy and carbon source for rapid metabolic responses. Taken together, our analysis could be used as an initial road map for the identification of different pathways that could be used to augment the rapid response of plants to abiotic stress. In addition, it highlights the important role of glutathione in these responses.

Effect of chronic mild stress on hippocampal transcriptome in mice selected for high and low stress-induced analgesia and displaying different emotional behaviors.

PubMed

Lisowski, Pawel; Juszczak, Grzegorz R; Goscik, Joanna; Wieczorek, Marek; Zwierzchowski, Lech; Swiergiel, Artur H

2011-01-01

There is increasing evidence that mood disorders may derive from the impact of environmental pressure on genetically susceptible individuals. Stress-induced hippocampal plasticity has been implicated in depression. We studied hippocampal transcriptomes in strains of mice that display high (HA) and low (LA) swim stress-induced analgesia and that differ in emotional behaviors and responses to different classes of antidepressants. Chronic mild stress (CMS) affected expression of a number of genes common for both strains. CMS also produced strain specific changes in expression suggesting that hippocampal responses to stress depend on genotype. Considerably larger number of genes, biological processes, molecular functions, biochemical pathways, and gene networks were affected by CMS in LA than in HA mice. The results suggest that potential drug targets against detrimental effects of stress include glutamate transporters, and cholinergic, cholecystokinin (CCK), glucocorticoids, and thyroid hormones receptors. Furthermore, some biological processes evoked by stress and different between the strains, such as apoptosis, neurogenesis and chromatin modifications, may be responsible for the long-term, irreversible effects of stress and suggest a role for epigenetic regulation of mood related stress responses. Copyright © 2010 Elsevier B.V. and ECNP. All rights reserved.

Identification of the acclimation genes in transcriptomic responses to heat stress of White Pekin duck.

PubMed

Kim, Jun-Mo; Lim, Kyu-Sang; Byun, Mijeong; Lee, Kyung-Tai; Yang, Young-Rok; Park, Mina; Lim, Dajeong; Chai, Han-Ha; Bang, Han-Tae; Hwangbo, Jong; Choi, Yang-Ho; Cho, Yong-Min; Park, Jong-Eun

2017-11-01

White Pekin duck is an important meat resource in the livestock industries. However, the temperature increase due to global warming has become a serious environmental factor in duck production, because of hyperthermia. Therefore, identifying the gene regulations and understanding the molecular mechanism for adaptation to the warmer environment will provide insightful information on the acclimation system of ducks. This study examined transcriptomic responses to heat stress treatments (3 and 6 h at 35 °C) and control (C, 25 °C) using RNA-sequencing analysis of genes from the breast muscle tissue. Based on three distinct differentially expressed gene (DEG) sets (3H/C, 6H/C, and 6H/3H), the expression patterns of significant DEGs (absolute log2 > 1.0 and false discovery rate < 0.05) were clustered into three responsive gene groups divided into upregulated and downregulated genes. Next, we analyzed the clusters that showed relatively higher expression levels in 3H/C and lower levels in 6H/C with much lower or opposite levels in 6H/3H; we referred to these clusters as the adaptable responsive gene group. These genes were significantly enriched in the ErbB signaling pathway, neuroactive ligand-receptor interaction and type II diabetes mellitus in the KEGG pathways (P < 0.01). From the functional enrichment analysis and significantly regulated genes observed in the enriched pathways, we think that the adaptable responsive genes are responsible for the acclimation mechanism of ducks and suggest that the regulation of phosphoinositide 3-kinase genes including PIK3R6, PIK3R5, and PIK3C2B has an important relationship with the mechanisms of adaptation to heat stress in ducks.

AtRD22 and AtUSPL1, Members of the Plant-Specific BURP Domain Family Involved in Arabidopsis thaliana Drought Tolerance

PubMed Central

Harshavardhan, Vokkaliga Thammegowda; Van Son, Le; Seiler, Christiane; Junker, Astrid; Weigelt-Fischer, Kathleen; Klukas, Christian; Altmann, Thomas; Sreenivasulu, Nese; Bäumlein, Helmut; Kuhlmann, Markus

2014-01-01

Crop plants are regularly challenged by a range of environmental stresses which typically retard their growth and ultimately compromise economic yield. The stress response involves the reprogramming of approximately 4% of the transcriptome. Here, the behavior of AtRD22 and AtUSPL1, both members of the Arabidopsis thaliana BURP (BNM2, USP, RD22 and polygalacturonase isozyme) domain-containing gene family, has been characterized. Both genes are up-regulated as part of the abscisic acid (ABA) mediated moisture stress response. While AtRD22 transcript was largely restricted to the leaf, that of AtUSPL1 was more prevalent in the root. As the loss of function of either gene increased the plant's moisture stress tolerance, the implication was that their products act to suppress the drought stress response. In addition to the known involvement of AtUSPL1 in seed development, a further role in stress tolerance was demonstrated. Based on transcriptomic data and phenotype we concluded that the enhanced moisture stress tolerance of the two loss-of-function mutants is a consequence of an enhanced basal defense response. PMID:25333723

Transcriptome Analysis of Shewanella oneidensis MR-1 in Response to Elevated Salt Conditions

PubMed Central

Liu, Yongqing; Gao, Weimin; Wang, Yue; Wu, Liyou; Liu, Xueduan; Yan, Tinfeng; Alm, Eric; Arkin, Adam; Thompson, Dorothea K.; Fields, Matthew W.; Zhou, Jizhong

2005-01-01

Whole-genomic expression patterns were examined in Shewanella oneidensis cells exposed to elevated sodium chloride. Genes involved in Na+ extrusion and glutamate biosynthesis were significantly up-regulated, and the majority of chemotaxis/motility-related genes were significantly down-regulated. The data also suggested an important role for metabolic adjustment in salt stress adaptation in S. oneidensis. PMID:15774893

Functional and transcriptome analysis reveals an acclimatization strategy for abiotic stress tolerance mediated by Arabidopsis NF-YA family members.

PubMed

Leyva-González, Marco Antonio; Ibarra-Laclette, Enrique; Cruz-Ramírez, Alfredo; Herrera-Estrella, Luis

2012-01-01

Nuclear Factor Y (NF-Y) is a heterotrimeric complex formed by NF-YA/NF-YB/NF-YC subunits that binds to the CCAAT-box in eukaryotic promoters. In contrast to other organisms, in which a single gene encodes each subunit, in plants gene families of over 10 members encode each of the subunits. Here we report that five members of the Arabidopsis thaliana NF-YA family are strongly induced by several stress conditions via transcriptional and miR169-related post-transcriptional mechanisms. Overexpression of NF-YA2, 7 and 10 resulted in dwarf late-senescent plants with enhanced tolerance to several types of abiotic stress. These phenotypes are related to alterations in sucrose/starch balance and cell elongation observed in NF-YA overexpressing plants. The use of transcriptomic analysis of transgenic plants that express miR169-resistant versions of NF-YA2, 3, 7, and 10 under an estradiol inducible system, as well as a dominant-repressor version of NF-YA2 revealed a set of genes, whose promoters are enriched in NF-Y binding sites (CCAAT-box) and that may be directly regulated by the NF-Y complex. This analysis also suggests that NF-YAs could participate in modulating gene regulation through positive and negative mechanisms. We propose a model in which the increase in NF-YA transcript levels in response to abiotic stress is part of an adaptive response to adverse environmental conditions in which a reduction in plant growth rate plays a key role.

Functional and Transcriptome Analysis Reveals an Acclimatization Strategy for Abiotic Stress Tolerance Mediated by Arabidopsis NF-YA Family Members

PubMed Central

Leyva-González, Marco Antonio; Ibarra-Laclette, Enrique; Cruz-Ramírez, Alfredo; Herrera-Estrella, Luis

2012-01-01

Nuclear Factor Y (NF-Y) is a heterotrimeric complex formed by NF-YA/NF-YB/NF-YC subunits that binds to the CCAAT-box in eukaryotic promoters. In contrast to other organisms, in which a single gene encodes each subunit, in plants gene families of over 10 members encode each of the subunits. Here we report that five members of the Arabidopsis thaliana NF-YA family are strongly induced by several stress conditions via transcriptional and miR169-related post-transcriptional mechanisms. Overexpression of NF-YA2, 7 and 10 resulted in dwarf late-senescent plants with enhanced tolerance to several types of abiotic stress. These phenotypes are related to alterations in sucrose/starch balance and cell elongation observed in NF-YA overexpressing plants. The use of transcriptomic analysis of transgenic plants that express miR169-resistant versions of NF-YA2, 3, 7, and 10 under an estradiol inducible system, as well as a dominant-repressor version of NF-YA2 revealed a set of genes, whose promoters are enriched in NF-Y binding sites (CCAAT-box) and that may be directly regulated by the NF-Y complex. This analysis also suggests that NF-YAs could participate in modulating gene regulation through positive and negative mechanisms. We propose a model in which the increase in NF-YA transcript levels in response to abiotic stress is part of an adaptive response to adverse environmental conditions in which a reduction in plant growth rate plays a key role. PMID:23118940

Transcriptomic analysis provides insight into high-altitude acclimation in domestic goats.

PubMed

Tang, Qianzi; Huang, Wenyao; Guan, Jiuqiang; Jin, Long; Che, Tiandong; Fu, Yuhua; Hu, Yaodong; Tian, Shilin; Wang, Dawei; Jiang, Zhi; Li, Xuewei; Li, Mingzhou

2015-08-10

Domestic goats are distributed in a wide range of habitats and have acclimated to their local environmental conditions. To investigate the gene expression changes of goats that are induced by high altitude stress, we performed RNA-seq on 27 samples from the three hypoxia-sensitive tissues (heart, lung, and skeletal muscle) in three indigenous populations from distinct altitudes (600 m, 2000 m, and 3000 m). We generated 129Gb of high-quality sequencing data (~4Gb per sample) and catalogued the expression profiles of 12,421 annotated hircine genes in each sample. The analysis showed global similarities and differences of high-altitude transcriptomes among populations and tissues as well as revealed that the heart underwent the most high-altitude induced expression changes. We identified numerous differentially expressed genes that exhibited distinct expression patterns, and nonsynonymous single nucleotide variant-containing genes that were highly differentiated between the high- and low-altitude populations. These genes have known or potential roles in hypoxia response and were enriched in functional gene categories potentially responsible for high-altitude stress. Therefore, they are appealing candidates for further investigation of the gene expression and associated regulatory mechanisms related to high-altitude acclimation. Copyright © 2015 Elsevier B.V. All rights reserved.

Biofilm Formation by Clostridium ljungdahlii Is Induced by Sodium Chloride Stress: Experimental Evaluation and Transcriptome Analysis.

PubMed

Philips, Jo; Rabaey, Korneel; Lovley, Derek R; Vargas, Madeline

2017-01-01

The acetogen Clostridium ljungdahlii is capable of syngas fermentation and microbial electrosynthesis. Biofilm formation could benefit both these applications, but was not yet reported for C. ljungdahlii. Biofilm formation does not occur under standard growth conditions, but attachment or aggregation could be induced by different stresses. The strongest biofilm formation was observed with the addition of sodium chloride. After 3 days of incubation, the biomass volume attached to a plastic surface was 20 times higher with than without the addition of 200 mM NaCl to the medium. The addition of NaCl also resulted in biofilm formation on glass, graphite and glassy carbon, the latter two being often used electrode materials for microbial electrosynthesis. Biofilms were composed of extracellular proteins, polysaccharides, as well as DNA, while pilus-like appendages were observed with, but not without, the addition of NaCl. A transcriptome analysis comparing planktonic (no NaCl) and biofilm (NaCl addition) cells showed that C. ljungdahlii coped with the salt stress by the upregulation of the general stress response, Na+ export and osmoprotectant accumulation. A potential role for poly-N-acetylglucosamines and D-alanine in biofilm formation was found. Flagellar motility was downregulated, while putative type IV pili biosynthesis genes were not expressed. Moreover, the gene expression analysis suggested the involvement of the transcriptional regulators LexA, Spo0A and CcpA in stress response and biofilm formation. This study showed that NaCl addition might be a valuable strategy to induce biofilm formation by C. ljungdahlii, which can improve the efficacy of syngas fermentation and microbial electrosynthesis applications.

Biofilm Formation by Clostridium ljungdahlii Is Induced by Sodium Chloride Stress: Experimental Evaluation and Transcriptome Analysis

PubMed Central

Rabaey, Korneel; Lovley, Derek R.; Vargas, Madeline

2017-01-01

The acetogen Clostridium ljungdahlii is capable of syngas fermentation and microbial electrosynthesis. Biofilm formation could benefit both these applications, but was not yet reported for C. ljungdahlii. Biofilm formation does not occur under standard growth conditions, but attachment or aggregation could be induced by different stresses. The strongest biofilm formation was observed with the addition of sodium chloride. After 3 days of incubation, the biomass volume attached to a plastic surface was 20 times higher with than without the addition of 200 mM NaCl to the medium. The addition of NaCl also resulted in biofilm formation on glass, graphite and glassy carbon, the latter two being often used electrode materials for microbial electrosynthesis. Biofilms were composed of extracellular proteins, polysaccharides, as well as DNA, while pilus-like appendages were observed with, but not without, the addition of NaCl. A transcriptome analysis comparing planktonic (no NaCl) and biofilm (NaCl addition) cells showed that C. ljungdahlii coped with the salt stress by the upregulation of the general stress response, Na+ export and osmoprotectant accumulation. A potential role for poly-N-acetylglucosamines and D-alanine in biofilm formation was found. Flagellar motility was downregulated, while putative type IV pili biosynthesis genes were not expressed. Moreover, the gene expression analysis suggested the involvement of the transcriptional regulators LexA, Spo0A and CcpA in stress response and biofilm formation. This study showed that NaCl addition might be a valuable strategy to induce biofilm formation by C. ljungdahlii, which can improve the efficacy of syngas fermentation and microbial electrosynthesis applications. PMID:28118386

Transcriptomic analysis of the mussel Elliptio complanata identifies candidate stress-response genes and an abundance of novel or noncoding transcripts

USGS Publications Warehouse

Cornman, Robert S.; Robertson, Laura S.; Galbraith, Heather S.; Blakeslee, Carrie J.

2014-01-01

Mussels are useful indicator species of environmental stress and degradation, and the global decline in freshwater mussel diversity and abundance is of conservation concern. Elliptio complanata is a common freshwater mussel of eastern North America that can serve both as an indicator and as an experimental model for understanding mussel physiology and genetics. To support genetic components of these research goals, we assembled transcriptome contigs from Illumina paired-end reads. Despite efforts to collapse similar contigs, the final assembly was in excess of 136,000 contigs with an N50 of 982 bp. Even so, comparisons to the CEGMA database of conserved eukaryotic genes indicated that ∼20% of genes remain unrepresented. However, numerous candidate stress-response genes were present, and we identified lineage-specific patterns of diversification among molluscs for cytochrome P450 detoxification genes and two saccharide-modifying enzymes: 1,3 beta-galactosyltransferase and fucosyltransferase. Less than a quarter of contigs had protein-level similarity based on modest BLAST and Hmmer3 statistical thresholds. These results add comparative genomic resources for molluscs and suggest a wealth of novel proteins and noncoding transcripts.

Transcriptomic analysis of the highly efficient oil-degrading bacterium Acinetobacter venetianus RAG-1 reveals genes important in dodecane uptake and utilization [Transcriptomic analysis of the marine oil-degrading bacterium Acinetobacter venetianus RAG-1 reveals genes important in dodecane uptake and utilization

DOE PAGES

Kothari, Ankita; Charrier, Marimikel; Wu, Yu -Wei; ...

2016-09-22

The hydrocarbonoclastic bacterium Acinetobacter venetianus RAG-1 has attracted substantial attention due to its powerful oil-degrading capabilities and its potential to play an important ecological role in the cleanup of alkanes. In this study, we compare the transcriptome of the strain RAG-1 grown in dodecane, the corresponding alkanol (dodecanol), and sodium acetate for the characterization of genes involved in dodecane uptake and utilization. Comparison of the transcriptional responses of RAG-1 grown on dodecane led to the identification of 1074 genes that were differentially expressed relative to sodium acetate. Of these, 622 genes were upregulated when grown in dodecane. The highly upregulatedmore » genes were involved in alkane catabolism, along with stress response. Our data suggest AlkMb to be primarily involved in dodecane oxidation. Transcriptional response of RAG-1 grown on dodecane relative to dodecanol also led to the identification of permease, outer membrane protein and thin fimbriae coding genes potentially involved in dodecane uptake. As a result, this study provides the first model for key genes involved in alkane uptake and metabolism in A. venetianus RAG-1.« less

Transcriptomic analysis of the highly efficient oil-degrading bacterium Acinetobacter venetianus RAG-1 reveals genes important in dodecane uptake and utilization [Transcriptomic analysis of the marine oil-degrading bacterium Acinetobacter venetianus RAG-1 reveals genes important in dodecane uptake and utilization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kothari, Ankita; Charrier, Marimikel; Wu, Yu -Wei

The hydrocarbonoclastic bacterium Acinetobacter venetianus RAG-1 has attracted substantial attention due to its powerful oil-degrading capabilities and its potential to play an important ecological role in the cleanup of alkanes. In this study, we compare the transcriptome of the strain RAG-1 grown in dodecane, the corresponding alkanol (dodecanol), and sodium acetate for the characterization of genes involved in dodecane uptake and utilization. Comparison of the transcriptional responses of RAG-1 grown on dodecane led to the identification of 1074 genes that were differentially expressed relative to sodium acetate. Of these, 622 genes were upregulated when grown in dodecane. The highly upregulatedmore » genes were involved in alkane catabolism, along with stress response. Our data suggest AlkMb to be primarily involved in dodecane oxidation. Transcriptional response of RAG-1 grown on dodecane relative to dodecanol also led to the identification of permease, outer membrane protein and thin fimbriae coding genes potentially involved in dodecane uptake. As a result, this study provides the first model for key genes involved in alkane uptake and metabolism in A. venetianus RAG-1.« less

Genome-Wide Identification and Expression Analysis of the Mitogen-Activated Protein Kinase Gene Family in Cassava

PubMed Central

Yan, Yan; Wang, Lianzhe; Ding, Zehong; Tie, Weiwei; Ding, Xupo; Zeng, Changying; Wei, Yunxie; Zhao, Hongliang; Peng, Ming; Hu, Wei

2016-01-01

Mitogen-activated protein kinases (MAPKs) play central roles in plant developmental processes, hormone signaling transduction, and responses to abiotic stress. However, no data are currently available about the MAPK family in cassava, an important tropical crop. Herein, 21 MeMAPK genes were identified from cassava. Phylogenetic analysis indicated that MeMAPKs could be classified into four subfamilies. Gene structure analysis demonstrated that the number of introns in MeMAPK genes ranged from 1 to 10, suggesting large variation among cassava MAPK genes. Conserved motif analysis indicated that all MeMAPKs had typical protein kinase domains. Transcriptomic analysis suggested that MeMAPK genes showed differential expression patterns in distinct tissues and in response to drought stress between wild subspecies and cultivated varieties. Interaction networks and co-expression analyses revealed that crucial pathways controlled by MeMAPK networks may be involved in the differential response to drought stress in different accessions of cassava. Expression of nine selected MAPK genes showed that these genes could comprehensively respond to osmotic, salt, cold, oxidative stressors, and abscisic acid (ABA) signaling. These findings yield new insights into the transcriptional control of MAPK gene expression, provide an improved understanding of abiotic stress responses and signaling transduction in cassava, and lead to potential applications in the genetic improvement of cassava cultivars. PMID:27625666

Systemic response of the stony coral Pocillopora damicornis against acute cadmium stress.

PubMed

Zhou, Zhi; Yu, Xiaopeng; Tang, Jia; Wu, Yibo; Wang, Lingui; Huang, Bo

2018-01-01

Heavy metals have become one of the main pollutants in the marine environment and a major threat to the growth and reproduction of stony corals. In the present study, the density of symbiotic zooxanthellae, levels of crucial physiological activities and the transcriptome were investigated in the stony coral Pocillopora damicornis after the acute exposure to elevated cadmium concentration. The density of symbiotic zooxanthellae decreased significantly during 12-24h period, and reached lowest at 24h after acute cadmium stress. No significant changes were observed in the activity of glutathione S-transferase during the entire stress exposure. The activities of superoxide dismutase and catalase, and the concentration of glutathione decreased significantly, but the activation level of caspase3 increased significantly after cadmium exposure. Furthermore, transcriptome sequencing and bioinformatics analysis revealed 3538 significantly upregulated genes and 8048 significantly downregulated genes at 12h after the treatment. There were 12 overrepresented GO terms for significantly upregulated genes, mostly related to unfolded protein response, endoplasmic reticulum stress and apoptosis. In addition, a total of 32 GO terms were overrepresented for significantly downregulated genes, and mainly correlated with macromolecular metabolic processes. These results collectively suggest that acute cadmium stress could induce apoptosis by repressing the production of the antioxidants, elevating oxidative stress and activating the unfolded protein response. This cascade of reactions would result to the collapse of the coral-zooxanthella symbiosis and the expulsion of symbiotic zooxanthellae in the stony coral P. damicornis, ultimately leading to coral bleaching. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparative Transcriptome Analysis of Bombyx mori (Lepidoptera) Larval Midgut Response to BmNPV in Susceptible and Near-Isogenic Resistant Strains

PubMed Central

Geng, Lei; Xu, Jia-Ping; Yu, Dong; Zhang, Shang-Zhi; Ma, Yan; Fei, Dong-Qiong

2016-01-01

Bombyx mori nucleopolyhedrovirus (BmNPV) is one of the primary pathogens causing severe economic losses in sericulture. However, the molecular mechanism of silkworm resistance to BmNPV remains largely unknown. Here, the recurrent parent P50 (susceptible strain) and the near-isogenic line BC9 (resistance strain) were used in a comparative transcriptome study examining the response to infection with BmNPV. A total of 14,300 unigenes were obtained from two different resistant strains; of these, 869 differentially expressed genes (DEGs) were identified after comparing the four transcriptomes. Many DEGs associated with protein metabolism, cytoskeleton, and apoptosis may be involved in the host response to BmNPV infection. Moreover, some immunity related genes were also altered following BmNPV infection. Specifically, after removing genetic background and individual immune stress response genes, 22 genes were found to be potentially involved in repressing BmNPV infection. These genes were related to transport, virus replication, intracellular innate immune, and apoptosis. Our study provided an overview of the molecular mechanism of silkworm resistance to BmNPV infection and laid a foundation for controlling BmNPV in the future. PMID:27168061

Transcriptome analysis of salinity responsiveness in contrasting genotypes of finger millet (Eleusine coracana L.) through RNA-sequencing.

PubMed

Rahman, Hifzur; Jagadeeshselvam, N; Valarmathi, R; Sachin, B; Sasikala, R; Senthil, N; Sudhakar, D; Robin, S; Muthurajan, Raveendran

2014-07-01

Finger millet (Eleusine coracana L.) is a hardy cereal known for its superior level of tolerance against drought, salinity, diseases and its nutritional properties. In this study, attempts were made to unravel the physiological and molecular basis of salinity tolerance in two contrasting finger millet genotypes viz., CO 12 and Trichy 1. Physiological studies revealed that the tolerant genotype Trichy 1 had lower Na(+) to K(+) ratio in leaves and shoots, higher growth rate (osmotic tolerance) and ability to accumulate higher amount of total soluble sugar in leaves under salinity stress. We sequenced the salinity responsive leaf transcriptome of contrasting finger millet genotypes using IonProton platform and generated 27.91 million reads. Mapping and annotation of finger millet transcripts against rice gene models led to the identification of salinity responsive genes and genotype specific responses. Several functional groups of genes like transporters, transcription factors, genes involved in cell signaling, osmotic homeostasis and biosynthesis of compatible solutes were found to be highly up-regulated in the tolerant Trichy 1. Salinity stress inhibited photosynthetic capacity and photosynthesis related genes in the susceptible genotype CO 12. Several genes involved in cell growth and differentiation were found to be up-regulated in both the genotypes but more specifically in tolerant genotype. Genes involved in flavonoid biosynthesis were found to be down-regulated specifically in the salinity tolerant Trichy 1. This study provides a genome-wide transcriptional analysis of two finger millet genotypes differing in their level of salinity tolerance during a gradually progressing salinity stress under greenhouse conditions.

Transcriptome response to elevated CO2, water deficit, and thermal stress in peanut

USDA-ARS?s Scientific Manuscript database

Previously, our laboratories have performed gene expression studies using EST sequencing and spotted microarrays to investigate tissue-specific gene expression and response to abiotic stress. While these studies have provided valuable insight into these processes, they are constrained by sequencer t...

Transcriptomic signatures in seeds of apple (Malus domestica L. Borkh) during fruitlet abscission.

PubMed

Ferrero, Sergio; Carretero-Paulet, Lorenzo; Mendes, Marta Adelina; Botton, Alessandro; Eccher, Giulia; Masiero, Simona; Colombo, Lucia

2015-01-01

Abscission is the regulated process of detachment of an organ from a plant. In apple the abscission of fruits occurs during their early development to control the fruit load depending on the nutritional state of the plant. In order to control production and obtain fruits with optimal market qualities, the horticultural procedure of thinning is performed to further reduce the number of fruitlets. In this study we have conducted a transcriptomic profiling of seeds from two different types of fruitlets, according to size and position in the fruit cluster. Transcriptomic profiles of central and lateral fruit seeds were obtained by RNAseq. Comparative analysis was performed by the functional categorization of differentially expressed genes by means of Gene Ontology (GO) annotation of the apple genome. Our results revealed the overexpression of genes involved in responses to stress, hormone biosynthesis and also the response and/or transport of auxin and ethylene. A smaller set of genes, mainly related to ion transport and homeostasis, were found to be down-regulated. The transcriptome characterization described in this manuscript contributes to unravelling the molecular mechanisms and pathways involved in the physiological abscission of apple fruits and suggests a role for seeds in this process.

Transcriptomic Signatures in Seeds of Apple (Malus domestica L. Borkh) during Fruitlet Abscission

PubMed Central

Ferrero, Sergio; Carretero-Paulet, Lorenzo; Mendes, Marta Adelina; Botton, Alessandro; Eccher, Giulia; Masiero, Simona; Colombo, Lucia

2015-01-01

Abscission is the regulated process of detachment of an organ from a plant. In apple the abscission of fruits occurs during their early development to control the fruit load depending on the nutritional state of the plant. In order to control production and obtain fruits with optimal market qualities, the horticultural procedure of thinning is performed to further reduce the number of fruitlets. In this study we have conducted a transcriptomic profiling of seeds from two different types of fruitlets, according to size and position in the fruit cluster. Transcriptomic profiles of central and lateral fruit seeds were obtained by RNAseq. Comparative analysis was performed by the functional categorization of differentially expressed genes by means of Gene Ontology (GO) annotation of the apple genome. Our results revealed the overexpression of genes involved in responses to stress, hormone biosynthesis and also the response and/or transport of auxin and ethylene. A smaller set of genes, mainly related to ion transport and homeostasis, were found to be down-regulated. The transcriptome characterization described in this manuscript contributes to unravelling the molecular mechanisms and pathways involved in the physiological abscission of apple fruits and suggests a role for seeds in this process. PMID:25781174

Identification of the WRKY gene family and functional analysis of two genes in Caragana intermedia.

PubMed

Wan, Yongqing; Mao, Mingzhu; Wan, Dongli; Yang, Qi; Yang, Feiyun; Mandlaa; Li, Guojing; Wang, Ruigang

2018-02-09

WRKY transcription factors, one of the largest families of transcriptional regulators in plants, play important roles in plant development and various stress responses. The WRKYs of Caragana intermedia are still not well characterized, although many WRKYs have been identified in various plant species. We identified 53 CiWRKY genes from C. intermedia transcriptome data, 28 of which exhibited complete open reading frames (ORFs). These CiWRKYs were divided into three groups via phylogenetic analysis according to their WRKY domains and zinc finger motifs. Conserved domain analysis showed that the CiWRKY proteins contain a highly conserved WRKYGQK motif and two variant motifs (WRKYGKK and WKKYEEK). The subcellular localization of CiWRKY26 and CiWRKY28-1 indicated that these two proteins localized exclusively to nuclei, supporting their role as transcription factors. The expression patterns of the 28 CiWRKYs with complete ORFs were examined through quantitative real-time PCR (qRT-PCR) in various tissues and under different abiotic stresses (drought, cold, salt, high-pH and abscisic acid (ABA)). The results showed that each CiWRKY responded to at least one stress treatment. Furthermore, overexpression of CiWRKY75-1 and CiWRKY40-4 in Arabidopsis thaliana suppressed the drought stress tolerance of the plants and delayed leaf senescence, respectively. Fifty-three CiWRKY genes from the C. intermedia transcriptome were identified and divided into three groups via phylogenetic analysis. The expression patterns of the 28 CiWRKYs under different abiotic stresses suggested that each CiWRKY responded to at least one stress treatment. Overexpression of CiWRKY75-1 and CiWRKY40-4 suppressed the drought stress tolerance of Arabidopsis and delayed leaf senescence, respectively. These results provide a basis for the molecular mechanism through which CiWRKYs mediate stress tolerance.

Dissecting Tissue-Specific Transcriptomic Responses from Leaf and Roots under Salt Stress in Petunia hybrida Mitchell

PubMed Central

Villarino, Gonzalo H.; Hu, Qiwen; Scanlon, Michael J.; Mueller, Lukas; Mattson, Neil S.

2017-01-01

One of the primary objectives of plant biotechnology is to increase resistance to abiotic stresses, such as salinity. Salinity is a major abiotic stress and increasing crop resistant to salt continues to the present day as a major challenge. Salt stress disturbs cellular environment leading to protein misfolding, affecting normal plant growth and causing agricultural losses worldwide. The advent of state-of-the-art technologies such as high throughput mRNA sequencing (RNA-seq) has revolutionized whole-transcriptome analysis by allowing, with high precision, to measure changes in gene expression. In this work, we used tissue-specific RNA-seq to gain insight into the Petunia hybrida transcriptional responses under NaCl stress using a controlled hydroponic system. Roots and leaves samples were taken from a continuum of 48 h of acute 150 mM NaCl. This analysis revealed a set of tissue and time point specific differentially expressed genes, such as genes related to transport, signal transduction, ion homeostasis as well as novel and undescribed genes, such as Peaxi162Scf00003g04130 and Peaxi162Scf00589g00323 expressed only in roots under salt stress. In this work, we identified early and late expressed genes in response to salt stress while providing a core of differentially express genes across all time points and tissues, including the trehalose-6-phosphate synthase 1 (TPS1), a glycosyltransferase reported in salt tolerance in other species. To test the function of the novel petunia TPS1 allele, we cloned and showed that TPS1 is a functional plant gene capable of complementing the trehalose biosynthesis pathway in a yeast tps1 mutant. The list of candidate genes to enhance salt tolerance provided in this work constitutes a major effort to better understand the detrimental effects of salinity in petunia with direct implications for other economically important Solanaceous species. PMID:28771200

Genomic, transcriptomic and phenomic variation reveals the complex adaptation to stress response of modern maize breeding

USDA-ARS?s Scientific Manuscript database

Early maize adaptation to different agricultural environments was an important process associated with the creation of a stable food supply that allowed the evolution of human civilization in the Americas. To explore the mechanisms of maize adaptation, genomic, transcriptomic and phenomic data were ...

Comparative Analysis of Anther Transcriptome Profiles of Two Different Rice Male Sterile Lines Genotypes under Cold Stress.

PubMed

Bai, Bin; Wu, Jun; Sheng, Wen-Tao; Zhou, Bo; Zhou, Li-Jie; Zhuang, Wen; Yao, Dong-Ping; Deng, Qi-Yun

2015-05-18

Rice is highly sensitive to cold stress during reproductive developmental stages, and little is known about the mechanisms of cold responses in rice anther. Using the HiSeq™ 2000 sequencing platform, the anther transcriptome of photo thermo sensitive genic male sterile lines (PTGMS) rice Y58S and P64S (Pei'ai64S) were analyzed at the fertility sensitive stage under cold stress. Approximately 243 million clean reads were obtained from four libraries and aligned against the oryza indica genome and 1497 and 5652 differentially expressed genes (DEGs) were identified in P64S and Y58S, respectively. Both gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were conducted for these DEGs. Functional classification of DEGs was also carried out. The DEGs common to both genotypes were mainly involved in signal transduction, metabolism, transport, and transcriptional regulation. Most of the DEGs were unique for each comparison group. We observed that there were more differentially expressed MYB (Myeloblastosis) and zinc finger family transcription factors and signal transduction components such as calmodulin/calcium dependent protein kinases in the Y58S comparison group. It was also found that ribosome-related DEGs may play key roles in cold stress signal transduction. These results presented here would be particularly useful for further studies on investigating the molecular mechanisms of rice responses to cold stress.

Comparative Analysis of Anther Transcriptome Profiles of Two Different Rice Male Sterile Lines Genotypes under Cold Stress

PubMed Central

Bai, Bin; Wu, Jun; Sheng, Wen-Tao; Zhou, Bo; Zhou, Li-Jie; Zhuang, Wen; Yao, Dong-Ping; Deng, Qi-Yun

2015-01-01

Rice is highly sensitive to cold stress during reproductive developmental stages, and little is known about the mechanisms of cold responses in rice anther. Using the HiSeq™ 2000 sequencing platform, the anther transcriptome of photo thermo sensitive genic male sterile lines (PTGMS) rice Y58S and P64S (Pei’ai64S) were analyzed at the fertility sensitive stage under cold stress. Approximately 243 million clean reads were obtained from four libraries and aligned against the oryza indica genome and 1497 and 5652 differentially expressed genes (DEGs) were identified in P64S and Y58S, respectively. Both gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were conducted for these DEGs. Functional classification of DEGs was also carried out. The DEGs common to both genotypes were mainly involved in signal transduction, metabolism, transport, and transcriptional regulation. Most of the DEGs were unique for each comparison group. We observed that there were more differentially expressed MYB (Myeloblastosis) and zinc finger family transcription factors and signal transduction components such as calmodulin/calcium dependent protein kinases in the Y58S comparison group. It was also found that ribosome-related DEGs may play key roles in cold stress signal transduction. These results presented here would be particularly useful for further studies on investigating the molecular mechanisms of rice responses to cold stress. PMID:25993302

Integrating Genetic and Gene Co-expression Analysis Identifies Gene Networks Involved in Alcohol and Stress Responses

PubMed Central

Luo, Jie; Xu, Pei; Cao, Peijian; Wan, Hongjian; Lv, Xiaonan; Xu, Shengchun; Wang, Gangjun; Cook, Melloni N.; Jones, Byron C.; Lu, Lu; Wang, Xusheng

2018-01-01

Although the link between stress and alcohol is well recognized, the underlying mechanisms of how they interplay at the molecular level remain unclear. The purpose of this study is to identify molecular networks underlying the effects of alcohol and stress responses, as well as their interaction on anxiety behaviors in the hippocampus of mice using a systems genetics approach. Here, we applied a gene co-expression network approach to transcriptomes of 41 BXD mouse strains under four conditions: stress, alcohol, stress-induced alcohol and control. The co-expression analysis identified 14 modules and characterized four expression patterns across the four conditions. The four expression patterns include up-regulation in no restraint stress and given an ethanol injection (NOE) but restoration in restraint stress followed by an ethanol injection (RSE; pattern 1), down-regulation in NOE but rescue in RSE (pattern 2), up-regulation in both restraint stress followed by a saline injection (RSS) and NOE, and further amplification in RSE (pattern 3), and up-regulation in RSS but reduction in both NOE and RSE (pattern 4). We further identified four functional subnetworks by superimposing protein-protein interactions (PPIs) to the 14 co-expression modules, including γ-aminobutyric acid receptor (GABA) signaling, glutamate signaling, neuropeptide signaling, cAMP-dependent signaling. We further performed module specificity analysis to identify modules that are specific to stress, alcohol, or stress-induced alcohol responses. Finally, we conducted causality analysis to link genetic variation to these identified modules, and anxiety behaviors after stress and alcohol treatments. This study underscores the importance of integrative analysis and offers new insights into the molecular networks underlying stress and alcohol responses. PMID:29674951

Transcriptomic and biochemical evidence for the role of lysine biosynthesis against linoleic acid hydroperoxide-induced stress in Saccharomyces cerevisiae.

PubMed

O'Doherty, P J; Lyons, V; Tun, N M; Rogers, P J; Bailey, T D; Wu, M J

2014-12-01

Amino acid biosynthesis forms part of an integrated stress response against oxidants in Saccharomyces cerevisiae and higher eukaryotes. Here we show an essential protective role of the l-lysine biosynthesis pathway in response to the oxidative stress condition induced by the lipid oxidant-linoleic acid hydroperoxide (LoaOOH), by means of transcriptomic profiling and phenotypic analysis, and using the deletion mutant dal80∆ and lysine auxotroph lys1∆. A comprehensive up-regulation of lysine biosynthetic genes (LYS1, LYS2, LYS4, LYS9, LYS12, LYS20 and LYS21) was revealed in dal80Δ following the oxidant challenge. The lysine auxotroph (lys1∆) exhibited a significant decrease in growth compared with that of BY4743 upon exposure to LoaOOH, albeit with the sufficient provision of lysine in the medium. Furthermore, the growth of wild type BY4743 exposed to LoaOOH was also greatly reduced in lysine-deficient conditions, despite a full complement of lysine biosynthetic genes. Amino acid analysis of LoaOOH-treated yeast showed that the level of cellular lysine remained unchanged throughout oxidant challenge, suggesting that the induced lysine biosynthesis leads to a steady-state metabolism as compared to the untreated yeast cells. Together, these findings demonstrate that lysine availability and its biosynthesis pathway play an important role in protecting the cell from lipid peroxide-induced oxidative stress, which is directly related to understanding environmental stress and industrial yeast management in brewing, wine making and baking.

De novo characterisation of the greenlip abalone transcriptome (Haliotis laevigata) with a focus on the heat shock protein 70 (HSP70) family.

PubMed

Shiel, Brett P; Hall, Nathan E; Cooke, Ira R; Robinson, Nicholas A; Strugnell, Jan M

2015-02-01

Abalone (Haliotis) are economically important molluscs for fisheries and aquaculture industries worldwide. Despite this, genomic resources for abalone and molluscs are still limited. Here we present a description and functional annotation of the greenlip abalone (Haliotis laevigata) transcriptome. We present a focused analysis on the heat shock protein 70 (HSP70) family of genes with putative functions affecting temperature stress and immunity. A total of ~38 million paired end Illumina reads were obtained, resulting in a Trinity assembly of 222,172 contigs with minimum length of 200 base pairs and maximum length of 33 kilobases. The 20,702 contigs were annotated with gene descriptions by BLAST. We created a program to maximise the number of functionally annotated genes, and over 10,000 contigs were assigned Gene ontologies (GO terms). By using CateGOrizer, immunity related GO terms for stressors such as heat, hypoxia, oxidative stress and wounding received the highest counts. Twenty-six contigs with homology to the HSP70 family of genes were identified. Ninety-one putative single-nucleotide polymorphisms were observed in the abalone HSP70 contigs. Eleven of these were considered non-synonymous. The annotated transcriptome described in this study will be a useful basis for future work investigating the genetic response of abalone to stress.

Heterochromatin assembly and transcriptome repression by Set1 in coordination with a class II histone deacetylase

PubMed Central

Lorenz, David R; Meyer, Lauren F; Grady, Patrick J R; Meyer, Michelle M; Cam, Hugh P

2014-01-01

Histone modifiers play essential roles in controlling transcription and organizing eukaryotic genomes into functional domains. Here, we show that Set1, the catalytic subunit of the highly conserved Set1C/COMPASS complex responsible for histone H3K4 methylation (H3K4me), behaves as a repressor of the transcriptome largely independent of Set1C and H3K4me in the fission yeast Schizosaccharomyces pombe. Intriguingly, while Set1 is enriched at highly expressed and repressed loci, Set1 binding levels do not generally correlate with the levels of transcription. We show that Set1 is recruited by the ATF/CREB homolog Atf1 to heterochromatic loci and promoters of stress-response genes. Moreover, we demonstrate that Set1 coordinates with the class II histone deacetylase Clr3 in heterochromatin assembly at prominent chromosomal landmarks and repression of the transcriptome that includes Tf2 retrotransposons, noncoding RNAs, and regulators of development and stress-responses. Our study delineates a molecular framework for elucidating the functional links between transcriptome control and chromatin organization. DOI: http://dx.doi.org/10.7554/eLife.04506.001 PMID:25497836

Functional and transcriptomic analysis of the key unfolded protein response transcription factor HacA in Aspergillus oryzae.

PubMed

Zhou, Bin; Xie, Jingyi; Liu, Xiaokai; Wang, Bin; Pan, Li

2016-11-15

HacA is a conserved basic leucine zipper transcription factor that serves as the master transcriptional regulator in the unfolded protein response (UPR). To comprehensively evaluate the role of HacA in Aspergillus oryzae, a homokaryotic hacA disruption mutant (HacA-DE) and a strain that expressed a constitutively active form of HacA (HacA-CA) were successfully generated, and transcriptome analyses of these mutants were performed. Growth and phenotypic profiles demonstrated that hyphal growth and sporulation were impaired in the HacA-DE and HacA-CA strains that were grown on complete and minimal media, and the growth impairment was more pronounced for the HacA-CA strain. Compared with a wild-type (WT) strain, the transcriptome results indicated that differentially expressed genes in these mutants mainly fell into four categories: the protein secretory pathway, amino acid metabolism, lipid metabolism, and carbohydrate metabolism. Furthermore, we identified 80 and 36 genes of the secretory pathway whose expression significantly differed in the HacA-CA strain (compared with the WT and HacA-DE strains) and HacA-DE strain (compared with the WT strain), respectively, which mostly belonged to protein folding/UPR, glycosylation, and vesicle transport processes. Both the HacA-CA and HacA-DE strains exhibited reduced expression of extracellular enzymes, especially amylolytic enzymes, which resulted from the activation of the repression under secretion stress mechanism in response to endoplasmic reticulum stress. Collectively, our results suggest that the function of HacA is important not only for UPR induction, but also for growth and fungal physiology, as it serves to reduce secretion stress in A. oryzae. Copyright © 2016 Elsevier B.V. All rights reserved.

Genome-Wide Analysis of the GRF Family Reveals Their Involvement in Abiotic Stress Response in Cassava.

PubMed

Shang, Sang; Wu, Chunlai; Huang, Chao; Tie, Weiwei; Yan, Yan; Ding, Zehong; Xia, Zhiqiang; Wang, Wenquan; Peng, Ming; Tian, Libo; Hu, Wei

2018-02-20

GENERAL REGULATORY FACTOR (GRF) proteins play vital roles in the regulation of plant growth, development, and response to abiotic stress. However, little information is known for this gene family in cassava ( Manihot esculenta ). In this study, 15 MeGRFs were identified from the cassava genome and were clustered into the ε and the non-ε groups according to phylogenetic, conserved motif, and gene structure analyses. Transcriptomic analyses showed eleven Me GRFs with constitutively high expression in stems, leaves, and storage roots of two cassava genotypes. Expression analyses revealed that the majority of GRFs showed transcriptional changes under cold, osmotic, salt, abscisic acid (ABA), and H₂O₂ treatments. Six Me GRFs were found to be commonly upregulated by abiotic stress, ABA, and H₂O₂ treatments, which may be the converging points of multiple signaling pathways. Interaction network analysis identified 18 possible interactors of MeGRFs. Taken together, this study elucidates the transcriptional control of Me GRFs in tissue development and the responses of abiotic stress and related signaling in cassava. Some constitutively expressed, tissue-specific, and abiotic stress-responsive candidate MeGRF genes were identified for the further genetic improvement of crops.

Genome-wide characterization and expression analysis enables identification of abiotic stress-responsive MYB transcription factors in cassava (Manihot esculenta).

PubMed

Ruan, Meng-Bin; Guo, Xin; Wang, Bin; Yang, Yi-Ling; Li, Wen-Qi; Yu, Xiao-Ling; Zhang, Peng; Peng, Ming

2017-06-15

The myeloblastosis (MYB) transcription factor superfamily is the largest transcription factor family in plants, playing different roles during stress response. However, abiotic stress-responsive MYB transcription factors have not been systematically studied in cassava (Manihot esculenta), an important tropical tuber root crop. In this study, we used a genome-wide transcriptome analysis to predict 299 putative MeMYB genes in the cassava genome. Under drought and cold stresses, many MeMYB genes exhibited different expression patterns in cassava leaves, indicating that these genes might play a role in abiotic stress responses. We found that several stress-responsive MeMYB genes responded to abscisic acid (ABA) in cassava leaves. We characterize four MeMYBs, namely MeMYB1, MeMYB2, MeMYB4, and MeMYB9, as R2R3-MYB transcription factors. Furthermore, RNAi-driven repression of MeMYB2 resulted in drought and cold tolerance in transgenic cassava. Gene expression assays in wild-type and MeMYB2-RNAi cassava plants revealed that MeMYB2 may affect other MeMYBs as well as MeWRKYs under drought and cold stress, suggesting crosstalk between MYB and WRKY family genes under stress conditions in cassava. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Physiological and transcriptomic responses in the seed coat of field-grown soybean (Glycine max L. Merr.) to abiotic stress

USDA-ARS?s Scientific Manuscript database

Understanding how intensification of abiotic stress due to global climate change affects crop yields is important for continued agricultural productivity. Coupling genomic technologies with physiological crop responses in a dynamic field environment is an effective approach to dissect the mechanisms...

RNA-seq based transcriptomic analysis uncovers α-linolenic acid and jasmonic acid biosynthesis pathways respond to cold acclimation in Camellia japonica

PubMed Central

Li, Qingyuan; Lei, Sheng; Du, Kebing; Li, Lizhi; Pang, Xufeng; Wang, Zhanchang; Wei, Ming; Fu, Shao; Hu, Limin; Xu, Lin

2016-01-01

Camellia is a well-known ornamental flower native to Southeast of Asia, including regions such as Japan, Korea and South China. However, most species in the genus Camellia are cold sensitive. To elucidate the cold stress responses in camellia plants, we carried out deep transcriptome sequencing of ‘Jiangxue’, a cold-tolerant cultivar of Camellia japonica, and approximately 1,006 million clean reads were generated using Illumina sequencing technology. The assembly of the clean reads produced 367,620 transcripts, including 207,592 unigenes. Overall, 28,038 differentially expressed genes were identified during cold acclimation. Detailed elucidation of responses of transcription factors, protein kinases and plant hormone signalling-related genes described the interplay of signal that allowed the plant to fine-tune cold stress responses. On the basis of global gene regulation of unsaturated fatty acid biosynthesis- and jasmonic acid biosynthesis-related genes, unsaturated fatty acid biosynthesis and jasmonic acid biosynthesis pathways were deduced to be involved in the low temperature responses in C. japonica. These results were supported by the determination of the fatty acid composition and jasmonic acid content. Our results provide insights into the genetic and molecular basis of the responses to cold acclimation in camellia plants. PMID:27819341

Comprehensive Transcriptome Analysis of Response to Nickel Stress in White Birch (Betula papyrifera)

PubMed Central

Theriault, Gabriel; Michael, Paul; Nkongolo, Kabwe

2016-01-01

White birch (Betula papyrifera) is a dominant tree species of the Boreal Forest. Recent studies have shown that it is fairly resistant to heavy metal contamination, specifically to nickel. Knowledge of regulation of genes associated with metal resistance in higher plants is very sketchy. Availability and annotation of the dwarf birch (B. nana) enables the use of high throughout sequencing approaches to understanding responses to environmental challenges in other Betula species such as B. papyrifera. The main objectives of this study are to 1) develop and characterize the B. papyrifera transcriptome, 2) assess gene expression dynamics of B. papyrifera in response to nickel stress, and 3) describe gene function based on ontology. Nickel resistant and susceptible genotypes were selected and used for transcriptome analysis. A total of 208,058 trinity genes were identified and were assembled to 275,545 total trinity transcripts. The transcripts were mapped to protein sequences and based on best match; we annotated the B. papyrifera genes and assigned gene ontology. In total, 215,700 transcripts were annotated and were compared to the published B. nana genome. Overall, a genomic match for 61% transcripts with the reference genome was found. Expression profiles were generated and 62,587 genes were found to be significantly differentially expressed among the nickel resistant, susceptible, and untreated libraries. The main nickel resistance mechanism in B. papyrifera is a downregulation of genes associated with translation (in ribosome), binding, and transporter activities. Five candidate genes associated to nickel resistance were identified. They include Glutathione S–transferase, thioredoxin family protein, putative transmembrane protein and two Nramp transporters. These genes could be useful for genetic engineering of birch trees. PMID:27082755

Whole-transcriptome response to water stress in a California endemic oak, Quercus lobata.

PubMed

Gugger, Paul F; Peñaloza-Ramírez, Juan Manuel; Wright, Jessica W; Sork, Victoria L

2017-05-01

Reduced water availability during drought can create major stress for many plant species. Within a species, populations with a history of seasonal drought may have evolved the ability to tolerate drought more than those in areas of high precipitation and low seasonality. In this study, we assessed response to water stress in a California oak species, Quercus lobata Née, by measuring changes in gene expression profiles before and after a simulated drought stress treatment through water deprivation of seedlings in a greenhouse setting. Using whole-transcriptome sequencing from nine samples from three collection localities, we identified which genes are involved in response to drought stress and tested the hypothesis that seedlings sampled from climatically different regions of the species range respond to water stress differently. We observed a surprisingly massive transcriptional response to drought: 35,347 of 68,434 contigs (52%) were differentially expressed before versus after drought treatment, of which 18,111 were down-regulated and 17,236 were up-regulated. Genes functionally associated with abiotic stresses and death were enriched among the up-regulated genes, whereas metabolic and cell part-related genes were enriched among the down-regulated. We found 56 contigs that exhibited significantly different expression responses to the drought treatment among the three populations (treatment × population interaction), suggesting that those genes may be involved in local adaptation to drought stress. These genes have stress response (e.g., WRKY DNA-binding protein 51 and HSP20-like chaperones superfamily protein), metabolic (e.g., phosphoglycerate kinase and protein kinase superfamily protein), transport/transfer (e.g., cationic amino acid transporter 7 and K+ transporter) and regulatory functions (e.g., WRKY51 and Homeodomain-like transcriptional regulator). Baseline expression levels of 1310 unique contigs also differed among pairs of populations, and they were enriched for metabolic and cell part-related genes. Out of the large fraction of the transcriptome that was differentially expressed in response to our drought treatment, we identified several novel genes that are candidates for involvement in local adaptation to drought. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Transcriptomic Profiling of the Maize (Zea mays L.) Leaf Response to Abiotic Stresses at the Seedling Stage.

PubMed

Li, Pengcheng; Cao, Wei; Fang, Huimin; Xu, Shuhui; Yin, Shuangyi; Zhang, Yingying; Lin, Dezhou; Wang, Jianan; Chen, Yufei; Xu, Chenwu; Yang, Zefeng

2017-01-01

Abiotic stresses, including drought, salinity, heat, and cold, negatively affect maize ( Zea mays L.) development and productivity. To elucidate the molecular mechanisms of resistance to abiotic stresses in maize, RNA-seq was used for global transcriptome profiling of B73 seedling leaves exposed to drought, salinity, heat, and cold stress. A total of 5,330 differentially expressed genes (DEGs) were detected in differential comparisons between the control and each stressed sample, with 1,661, 2,019, 2,346, and 1,841 DEGs being identified in comparisons of the control with salinity, drought, heat, and cold stress, respectively. Functional annotations of DEGs suggested that the stress response was mediated by pathways involving hormone metabolism and signaling, transcription factors (TFs), very-long-chain fatty acid biosynthesis and lipid signaling, among others. Of the obtained DEGs (5,330), 167 genes are common to these four abiotic stresses, including 10 up-regulated TFs (five ERFs, two NACs, one ARF, one MYB, and one HD-ZIP) and two down-regulated TFs (one b-ZIP and one MYB-related), which suggested that common mechanisms may be initiated in response to different abiotic stresses in maize. This study contributes to a better understanding of the molecular mechanisms of maize leaf responses to abiotic stresses and could be useful for developing maize cultivars resistant to abiotic stresses.

Transcriptomic analysis reveals the flooding tolerant mechanism in flooding tolerant line and abscisic acid treated soybean.

PubMed

Yin, Xiaojian; Hiraga, Susumu; Hajika, Makita; Nishimura, Minoru; Komatsu, Setsuko

2017-03-01

Soybean is highly sensitive to flooding stress and exhibits markedly reduced plant growth and grain yield under flooding conditions. To explore the mechanisms underlying initial flooding tolerance in soybean, RNA sequencing-based transcriptomic analysis was performed using a flooding-tolerant line and ABA-treated soybean. A total of 31 genes included 12 genes that exhibited similar temporal patterns were commonly changed in these plant groups in response to flooding and they were mainly involved in RNA regulation and protein metabolism. The mRNA expression of matrix metalloproteinase, glucose-6-phosphate isomerase, ATPase family AAA domain-containing protein 1, and cytochrome P450 77A1 was up-regulated in wild-type soybean under flooding conditions; however, no changes were detected in the flooding-tolerant line or ABA-treated soybean. The mRNA expression of cytochrome P450 77A1 was specifically up-regulated in root tips by flooding stress, but returned to the level found in control plants following treatment with the P450 inhibitor uniconazole. The survival ratio and root fresh weight of plants were markedly improved by 3-h uniconazole treatment under flooding stress. Taken together, these results suggest that cytochrome P450 77A1 is suppressed by uniconazole treatment and that this inhibition may enhance soybean tolerance to flooding stress.

Gene expression profiling of flax (Linum usitatissimum L.) under edaphic stress.

PubMed

Dmitriev, Alexey A; Kudryavtseva, Anna V; Krasnov, George S; Koroban, Nadezhda V; Speranskaya, Anna S; Krinitsina, Anastasia A; Belenikin, Maxim S; Snezhkina, Anastasiya V; Sadritdinova, Asiya F; Kishlyan, Natalya V; Rozhmina, Tatiana A; Yurkevich, Olga Yu; Muravenko, Olga V; Bolsheva, Nadezhda L; Melnikova, Nataliya V

2016-11-16

Cultivated flax (Linum usitatissimum L.) is widely used for production of textile, food, chemical and pharmaceutical products. However, various stresses decrease flax production. Search for genes, which are involved in stress response, is necessary for breeding of adaptive cultivars. Imbalanced concentration of nutrient elements in soil decrease flax yields and also results in heritable changes in some flax lines. The appearance of Linum Insertion Sequence 1 (LIS-1) is the most studied modification. However, LIS-1 function is still unclear. High-throughput sequencing of transcriptome of flax plants grown under normal (N), phosphate deficient (P), and nutrient excess (NPK) conditions was carried out using Illumina platform. The assembly of transcriptome was performed, and a total of 34924, 33797, and 33698 unique transcripts for N, P, and NPK sequencing libraries were identified, respectively. We have not revealed any LIS-1 derived mRNA in our sequencing data. The analysis of high-throughput sequencing data allowed us to identify genes with potentially differential expression under imbalanced nutrition. For further investigation with qPCR, 15 genes were chosen and their expression levels were evaluated in the extended sampling of 31 flax plants. Significant expression alterations were revealed for genes encoding WRKY and JAZ protein families under P and NPK conditions. Moreover, the alterations of WRKY family genes differed depending on LIS-1 presence in flax plant genome. Besides, we revealed slight and LIS-1 independent mRNA level changes of KRP2 and ING1 genes, which are adjacent to LIS-1, under nutrition stress. Differentially expressed genes were identified in flax plants, which were grown under phosphate deficiency and excess nutrition, on the basis of high-throughput sequencing and qPCR data. We showed that WRKY and JAS gene families participate in flax response to imbalanced nutrient content in soil. Besides, we have not identified any mRNA, which could be derived from LIS-1, in our transcriptome sequencing data. Expression of LIS-1 flanking genes, ING1 and KRP2, was suggested not to be nutrient stress-induced. Obtained results provide new insights into edaphic stress response in flax and the role of LIS-1 in these process.

Transcriptome Analysis in Haematococcus pluvialis: Astaxanthin Induction by Salicylic Acid (SA) and Jasmonic Acid (JA).

PubMed

Gao, Zhengquan; Li, Yan; Wu, Guanxun; Li, Guoqiang; Sun, Haifeng; Deng, Suzhen; Shen, Yicheng; Chen, Guoqiang; Zhang, Ruihao; Meng, Chunxiao; Zhang, Xiaowen

2015-01-01

Haematococcus pluvialis is an astaxanthin-rich microalga that can increase its astaxanthin production by salicylic acid (SA) or jasmonic acid (JA) induction. The genetic transcriptome details of astaxanthin biosynthesis were analyzed by exposing the algal cells to 25 mg/L of SA and JA for 1, 6 and 24 hours, plus to the control (no stress). Based on the RNA-seq analysis, 56,077 unigenes (51.7%) were identified with functions in response to the hormone stress. The top five identified subcategories were cell, cellular process, intracellular, catalytic activity and cytoplasm, which possessed 5600 (~9.99%), 5302 (~9.45%), 5242 (~9.35%), 4407 (~7.86%) and 4195 (~7.48%) unigenes, respectively. Furthermore, 59 unigenes were identified and assigned to 26 putative transcription factors (TFs), including 12 plant-specific TFs. They were likely associated with astaxanthin biosynthesis in Haematococcus upon SA and JA stress. In comparison, the up-regulation of differential expressed genes occurred much earlier, with higher transcript levels in the JA treatment (about 6 h later) than in the SA treatment (beyond 24 h). These results provide valuable information for directing metabolic engineering efforts to improve astaxanthin biosynthesis in H. pluvialis.

Editor's Highlight: Hydroxyurea Exposure Activates the P53 Signaling Pathway in Murine Organogenesis-Stage Embryos

PubMed Central

El Husseini, Nazem; Schlisser, Ava E.; Hales, Barbara F.

2016-01-01

Hydroxyurea, an anticancer agent and potent teratogen, induces oxidative stress and activates a DNA damage response pathway in the gestation day (GD) 9 mouse embryo. To delineate the stress response pathways activated by this drug, we investigated the effect of hydroxyurea exposure on the transcriptome of GD 9 embryos. Timed pregnant CD-1 mice were treated with saline or hydroxyurea (400 mg/kg or 600 mg/kg) on GD 9; embryonic gene and protein expression were examined 3 h later. Microarray analysis revealed that the expression of 1346 probe sets changed significantly in embryos exposed to hydroxyurea compared with controls; the P53 signaling pathway was highly affected. In addition, P53 related family members, P63 and P73, were predicted to be activated and had common and unique downstream targets. Western blot analysis revealed that active phospho-P53 was significantly increased in drug-exposed embryos; confocal microscopy showed that the translocation of phospho-P53 to the nucleus was widespread in the embryo. Furthermore, qRT-PCR showed that the expression of P53-regulated genes (Cdkn1A, Fas, and Trp53inp1) was significantly upregulated in hydroxyurea-exposed embryos; the concentration of the redox sensitive P53INP1 protein was also increased in a hydroxyurea dose-dependent fashion. Thus, hydroxyurea elicits a significant effect on the transcriptome of the organogenesis stage murine embryo, activating several key developmental signaling pathways related to DNA damage and oxidative stress. We propose that the P53 pathway plays a central role in the embryonic stress response and the developmental outcome after teratogen exposure. PMID:27208086

Transcriptomic changes in an animal-bacterial symbiosis under modeled microgravity conditions

PubMed Central

Casaburi, Giorgio; Goncharenko-Foster, Irina; Duscher, Alexandrea A.; Foster, Jamie S.

2017-01-01

Spaceflight imposes numerous adaptive challenges for terrestrial life. The reduction in gravity, or microgravity, represents a novel environment that can disrupt homeostasis of many physiological processes. Additionally, it is becoming increasingly clear that an organism’s microbiome is critical for host health and examining its resiliency in microgravity represents a new frontier for space biology research. In this study, we examine the impact of microgravity on the interactions between the squid Euprymna scolopes and its beneficial symbiont Vibrio fischeri, which form a highly specific binary mutualism. First, animals inoculated with V. fischeri aboard the space shuttle showed effective colonization of the host light organ, the site of the symbiosis, during space flight. Second, RNA-Seq analysis of squid exposed to modeled microgravity conditions exhibited extensive differential gene expression in the presence and absence of the symbiotic partner. Transcriptomic analyses revealed in the absence of the symbiont during modeled microgravity there was an enrichment of genes and pathways associated with the innate immune and oxidative stress response. The results suggest that V. fischeri may help modulate the host stress responses under modeled microgravity. This study provides a window into the adaptive responses that the host animal and its symbiont use during modeled microgravity. PMID:28393904

Transcriptome analysis of Gossypium hirsutum flower buds infested by cotton boll weevil (Anthonomus grandis) larvae.

PubMed

Artico, Sinara; Ribeiro-Alves, Marcelo; Oliveira-Neto, Osmundo Brilhante; de Macedo, Leonardo Lima Pepino; Silveira, Sylvia; Grossi-de-Sa, Maria Fátima; Martinelli, Adriana Pinheiro; Alves-Ferreira, Marcio

2014-10-04

Cotton is a major fibre crop grown worldwide that suffers extensive damage from chewing insects, including the cotton boll weevil larvae (Anthonomus grandis). Transcriptome analysis was performed to understand the molecular interactions between Gossypium hirsutum L. and cotton boll weevil larvae. The Illumina HiSeq 2000 platform was used to sequence the transcriptome of cotton flower buds infested with boll weevil larvae. The analysis generated a total of 327,489,418 sequence reads that were aligned to the G. hirsutum reference transcriptome. The total number of expressed genes was over 21,697 per sample with an average length of 1,063 bp. The DEGseq analysis identified 443 differentially expressed genes (DEG) in cotton flower buds infected with boll weevil larvae. Among them, 402 (90.7%) were up-regulated, 41 (9.3%) were down-regulated and 432 (97.5%) were identified as orthologues of A. thaliana genes using Blastx. Mapman analysis of DEG indicated that many genes were involved in the biotic stress response spanning a range of functions, from a gene encoding a receptor-like kinase to genes involved in triggering defensive responses such as MAPK, transcription factors (WRKY and ERF) and signalling by ethylene (ET) and jasmonic acid (JA) hormones. Furthermore, the spatial expression pattern of 32 of the genes responsive to boll weevil larvae feeding was determined by "in situ" qPCR analysis from RNA isolated from two flower structures, the stamen and the carpel, by laser microdissection (LMD). A large number of cotton transcripts were significantly altered upon infestation by larvae. Among the changes in gene expression, we highlighted the transcription of receptors/sensors that recognise chitin or insect oral secretions; the altered regulation of transcripts encoding enzymes related to kinase cascades, transcription factors, Ca2+ influxes, and reactive oxygen species; and the modulation of transcripts encoding enzymes from phytohormone signalling pathways. These data will aid in the selection of target genes to genetically engineer cotton to control the cotton boll weevil.

Large-scale transcriptome analysis reveals arabidopsis metabolic pathways are frequently influenced by different pathogens.

PubMed

Jiang, Zhenhong; He, Fei; Zhang, Ziding

2017-07-01

Through large-scale transcriptional data analyses, we highlighted the importance of plant metabolism in plant immunity and identified 26 metabolic pathways that were frequently influenced by the infection of 14 different pathogens. Reprogramming of plant metabolism is a common phenomenon in plant defense responses. Currently, a large number of transcriptional profiles of infected tissues in Arabidopsis (Arabidopsis thaliana) have been deposited in public databases, which provides a great opportunity to understand the expression patterns of metabolic pathways during plant defense responses at the systems level. Here, we performed a large-scale transcriptome analysis based on 135 previously published expression samples, including 14 different pathogens, to explore the expression pattern of Arabidopsis metabolic pathways. Overall, metabolic genes are significantly changed in expression during plant defense responses. Upregulated metabolic genes are enriched on defense responses, and downregulated genes are enriched on photosynthesis, fatty acid and lipid metabolic processes. Gene set enrichment analysis (GSEA) identifies 26 frequently differentially expressed metabolic pathways (FreDE_Paths) that are differentially expressed in more than 60% of infected samples. These pathways are involved in the generation of energy, fatty acid and lipid metabolism as well as secondary metabolite biosynthesis. Clustering analysis based on the expression levels of these 26 metabolic pathways clearly distinguishes infected and control samples, further suggesting the importance of these metabolic pathways in plant defense responses. By comparing with FreDE_Paths from abiotic stresses, we find that the expression patterns of 26 FreDE_Paths from biotic stresses are more consistent across different infected samples. By investigating the expression correlation between transcriptional factors (TFs) and FreDE_Paths, we identify several notable relationships. Collectively, the current study will deepen our understanding of plant metabolism in plant immunity and provide new insights into disease-resistant crop improvement.

Transcriptome and gene expression analysis of DHA producer Aurantiochytrium under low temperature conditions

PubMed Central

Ma, Zengxin; Tan, Yanzhen; Cui, Guzhen; Feng, Yingang; Cui, Qiu; Song, Xiaojin

2015-01-01

Aurantiochytrium is a promising docosahexaenoic acid (DHA) production candidate due to its fast growth rate and high proportions of lipid and DHA content. In this study, high-throughput RNA sequencing technology was employed to explore the acclimatization of this DHA producer under cold stress at the transcriptional level. The overall de novo assembly of the cDNA sequence data generated 29,783 unigenes, with an average length of 1,200 bp. In total, 13,245 unigenes were annotated in at least one database. A comparative genomic analysis between normal conditions and cold stress revealed that 2,013 genes were differentially expressed during the growth stage, while 2,071 genes were differentially expressed during the lipid accumulation stage. Further functional categorization and analyses showed some differentially expressed genes were involved in processes crucial to cold acclimation, such as signal transduction, cellular component biogenesis, and carbohydrate and lipid metabolism. A brief survey of the transcripts obtained in response to cold stress underlines the survival strategy of Aurantiochytrium; of these transcripts, many directly or indirectly influence the lipid composition. This is the first study to perform a transcriptomic analysis of the Aurantiochytrium under low temperature conditions. Our results will help to enhance DHA production by Aurantiochytrium in the future. PMID:26403200

Transcriptome and gene expression analysis of DHA producer Aurantiochytrium under low temperature conditions.

PubMed

Ma, Zengxin; Tan, Yanzhen; Cui, Guzhen; Feng, Yingang; Cui, Qiu; Song, Xiaojin

2015-09-25

Aurantiochytrium is a promising docosahexaenoic acid (DHA) production candidate due to its fast growth rate and high proportions of lipid and DHA content. In this study, high-throughput RNA sequencing technology was employed to explore the acclimatization of this DHA producer under cold stress at the transcriptional level. The overall de novo assembly of the cDNA sequence data generated 29,783 unigenes, with an average length of 1,200 bp. In total, 13,245 unigenes were annotated in at least one database. A comparative genomic analysis between normal conditions and cold stress revealed that 2,013 genes were differentially expressed during the growth stage, while 2,071 genes were differentially expressed during the lipid accumulation stage. Further functional categorization and analyses showed some differentially expressed genes were involved in processes crucial to cold acclimation, such as signal transduction, cellular component biogenesis, and carbohydrate and lipid metabolism. A brief survey of the transcripts obtained in response to cold stress underlines the survival strategy of Aurantiochytrium; of these transcripts, many directly or indirectly influence the lipid composition. This is the first study to perform a transcriptomic analysis of the Aurantiochytrium under low temperature conditions. Our results will help to enhance DHA production by Aurantiochytrium in the future.

Understanding the response to endurance exercise using a systems biology approach: combining blood metabolomics, transcriptomics and miRNomics in horses.

PubMed

Mach, Núria; Ramayo-Caldas, Yuliaxis; Clark, Allison; Moroldo, Marco; Robert, Céline; Barrey, Eric; López, Jesús Maria; Le Moyec, Laurence

2017-02-17

Endurance exercise in horses requires adaptive processes involving physiological, biochemical, and cognitive-behavioral responses in an attempt to regain homeostasis. We hypothesized that the identification of the relationships between blood metabolome, transcriptome, and miRNome during endurance exercise in horses could provide significant insights into the molecular response to endurance exercise. For this reason, the serum metabolome and whole-blood transcriptome and miRNome data were obtained from ten horses before and after a 160 km endurance competition. We obtained a global regulatory network based on 11 unique metabolites, 263 metabolic genes and 5 miRNAs whose expression was significantly altered at T1 (post- endurance competition) relative to T0 (baseline, pre-endurance competition). This network provided new insights into the cross talk between the distinct molecular pathways (e.g. energy and oxygen sensing, oxidative stress, and inflammation) that were not detectable when analyzing single metabolites or transcripts alone. Single metabolites and transcripts were carrying out multiple roles and thus sharing several biochemical pathways. Using a regulatory impact factor metric analysis, this regulatory network was further confirmed at the transcription factor and miRNA levels. In an extended cohort of 31 independent animals, multiple factor analysis confirmed the strong associations between lactate, methylene derivatives, miR-21-5p, miR-16-5p, let-7 family and genes that coded proteins involved in metabolic reactions primarily related to energy, ubiquitin proteasome and lipopolysaccharide immune responses after the endurance competition. Multiple factor analysis also identified potential biomarkers at T0 for an increased likelihood for failure to finish an endurance competition. To the best of our knowledge, the present study is the first to provide a comprehensive and integrated overview of the metabolome, transcriptome, and miRNome co-regulatory networks that may have a key role in regulating the metabolic and immune response to endurance exercise in horses.

Salt-Stress Response Mechanisms Using de Novo Transcriptome Sequencing of Salt-Tolerant and Sensitive Corchorus spp. Genotypes

PubMed Central

Yang, Zemao; Lu, Ruike; Dai, Zhigang; Yan, An; Tang, Qing; Cheng, Chaohua; Xu, Ying; Yang, Wenting; Su, Jianguang

2017-01-01

High salinity is a major environmental stressor for crops. To understand the regulatory mechanisms underlying salt tolerance, we conducted a comparative transcriptome analysis between salt-tolerant and salt-sensitive jute (Corchorus spp.) genotypes in leaf and root tissues under salt stress and control conditions. In total, 68,961 unigenes were identified. Additionally, 11,100 unigenes (including 385 transcription factors (TFs)) exhibited significant differential expression in salt-tolerant or salt-sensitive genotypes. Numerous common and unique differentially expressed unigenes (DEGs) between the two genotypes were discovered. Fewer DEGs were observed in salt-tolerant jute genotypes whether in root or leaf tissues. These DEGs were involved in various pathways, such as ABA signaling, amino acid metabolism, etc. Among the enriched pathways, plant hormone signal transduction (ko04075) and cysteine/methionine metabolism (ko00270) were the most notable. Eight common DEGs across both tissues and genotypes with similar expression profiles were part of the PYL-ABA-PP2C (pyrabactin resistant-like/regulatory components of ABA receptors-abscisic acid-protein phosphatase 2C). The methionine metabolism pathway was only enriched in salt-tolerant jute root tissue. Twenty-three DEGs were involved in methionine metabolism. Overall, numerous common and unique salt-stress response DEGs and pathways between salt-tolerant and salt-sensitive jute have been discovered, which will provide valuable information regarding salt-stress response mechanisms and help improve salt-resistance molecular breeding in jute. PMID:28927022

Global transcriptomic profiling demonstrates induction of oxidative stress and of compensatory cellular stress responses in brown trout exposed to glyphosate and Roundup.

PubMed

Uren Webster, Tamsyn M; Santos, Eduarda M

2015-01-31

Glyphosate, the active ingredient in Roundup formulations, is the most widely used herbicide worldwide, and as a result contaminates surface waters and has been detected in food residues, drinking water and human urine, raising concerns for potential environmental and human health impacts. Research has shown that glyphosate and Roundup can induce a broad range of biological effects in exposed organisms, particularly via generation of oxidative stress. However, there has been no comprehensive investigation of the global molecular mechanisms of toxicity of glyphosate and Roundup for any species. We aimed to characterise and compare the global mechanisms of toxicity of glyphosate and Roundup in the liver of brown trout (Salmo trutta), an ecologically and economically important vertebrate species, using RNA-seq on an Illumina HiSeq 2500 platform. To do this, we exposed juvenile female brown trout to 0, 0.01, 0.5 and 10 mg/L of glyphosate and Roundup (glyphosate acid equivalent) for 14 days, and sequenced 6 replicate liver samples from each treatment. We assembled the brown trout transcriptome using an optimised de novo approach, and subsequent differential expression analysis identified a total of 1020 differentially-regulated transcripts across all treatments. These included transcripts encoding components of the antioxidant system, a number of stress-response proteins and pro-apoptotic signalling molecules. Functional analysis also revealed over-representation of pathways involved in regulating of cell-proliferation and turnover, and up-regulation of energy metabolism and other metabolic processes. These transcriptional changes are consistent with generation of oxidative stress and the widespread induction of compensatory cellular stress response pathways. The mechanisms of toxicity identified were similar across both glyphosate and Roundup treatments, including for environmentally relevant concentrations. The significant alterations in transcript expression observed at the lowest concentrations tested raises concerns for the potential toxicity of this herbicide to fish populations inhabiting contaminated rivers.

Muscle transcriptome response to ACTH administration in a free-ranging marine mammal

PubMed Central

Champagne, Cory D.; Preeyanon, Likit; Ortiz, Rudy M.; Crocker, Daniel E.

2015-01-01

While much of our understanding of stress physiology is derived from biomedical studies, little is known about the downstream molecular consequences of adaptive stress responses in free-living animals. We examined molecular effectors of the stress hormones cortisol and aldosterone in the northern elephant seal, a free-ranging study system in which extreme physiological challenges and cortisol fluctuations are a routine part of life history. We stimulated the neuroendocrine stress axis by administering exogenous adrenocorticotropic hormone (ACTH) and examined the resultant effects by measuring corticosteroid hormones, metabolites, and gene expression before, during, and following administration. ACTH induced an elevation in cortisol, aldosterone, glucose, and fatty acids within 2 h, with complete recovery observed within 24 h of administration. The global transcriptional response of elephant seal muscle tissue to ACTH was evaluated by transcriptomics and involved upregulation of a highly coordinated network of conserved glucocorticoid (GC) target genes predicted to promote metabolic substrate availability without causing deleterious effects seen in laboratory animals. Transcriptional recovery from ACTH was characterized by downregulation of GC target genes and restoration of cell proliferation, metabolism, and tissue maintenance pathways within 24 h. Differentially expressed genes included several adipokines not previously described in muscle, reflecting unique metabolic physiology in fasting-adapted animals. This study represents one of the first transcriptome analyses of cellular responses to hypothalamic-pituitary-adrenal axis stimulation in a free-living marine mammal and suggests that compensatory, tissue-sparing mechanisms may enable marine mammals to maintain cortisol and aldosterone sensitivity while avoiding deleterious long-term consequences of stress. PMID:26038394

Identification and comparative analysis of the microRNA transcriptome in roots of two contrasting tobacco genotypes in response to cadmium stress

NASA Astrophysics Data System (ADS)

He, Xiaoyan; Zheng, Weite; Cao, Fangbin; Wu, Feibo

2016-09-01

Tobacco (Nicotiana tabacum L.) is more acclimated to cadmium (Cd) uptake and preferentially enriches Cd in leaves than other crops. MicroRNAs (miRNAs) play crucial roles in regulating expression of various stress response genes in plants. However, genome-wide expression of miRNAs and their target genes in response to Cd stress in tobacco are still unknown. Here, miRNA high-throughput sequencing technology was performed using two contrasting tobacco genotypes Guiyan 1 and Yunyan 2 of Cd-sensitive and tolerance. Comprehensive analysis of miRNA expression profiles in control and Cd treated plants identified 72 known (27 families) and 14 novel differentially expressed miRNAs in the two genotypes. Among them, 28 known (14 families) and 5 novel miRNAs were considered as Cd tolerance associated miRNAs, which mainly involved in cell growth, ion homeostasis, stress defense, antioxidant and hormone signaling. Finally, a hypothetical model of Cd tolerance mechanism in Yunyan 2 was presented. Our findings suggest that some miRNAs and their target genes and pathways may play critical roles in Cd tolerance.

Homoeolog-specific activation of genes for heat acclimation in the allopolyploid grass Brachypodium hybridum.

PubMed

Takahagi, Kotaro; Inoue, Komaki; Shimizu, Minami; Uehara-Yamaguchi, Yukiko; Onda, Yoshihiko; Mochida, Keiichi

2018-04-01

Allopolyploid plants often show wider environmental tolerances than their ancestors; this is expected to be due to the merger of multiple distinct genomes with a fixed heterozygosity. The complex homoeologous gene expression could have been evolutionarily advantageous for the adaptation of allopolyploid plants. Despite multiple previous studies reporting homoeolog-specific gene expression in allopolyploid species, there are no clear examples of homoeolog-specific function in acclimation to a long-term stress condition. We found that the allopolyploid grass Brachypodium hybridum and its ancestor Brachypodium stacei show long-term heat stress tolerance, unlike its other ancestor, Brachypodium distachyon. To understand the physiological traits of B. hybridum, we compared the transcriptome of the 3 Brachypodium species grown under normal and heat stress conditions. We found that the expression patterns of approximately 26% and approximately 38% of the homoeolog groups in B. hybridum changed toward nonadditive expression and nonancestral expression, respectively, under normal condition. Moreover, we found that B. distachyon showed similar expression patterns between normal and heat stress conditions, whereas B. hybridum and B. stacei significantly altered their transcriptome in response to heat after 3 days of stress exposure, and homoeologs that were inherited from B. stacei may have contributed to the transcriptional stress response to heat in B. hybridum. After 15 days of heat exposure, B. hybridum and B. stacei maintained transcriptional states similar to those under normal conditions. These results suggest that an earlier response to heat that was specific to homoeologs originating from B. stacei contributed to cellular homeostasis under long-term heat stress in B. hybridum. Our results provide insights into different regulatory events of the homoeo-transcriptome that are associated with stress acclimation in allopolyploid plants.

Uncovering a Dual Regulatory Role for Caspases During Endoplasmic Reticulum Stress-induced Cell Death.

PubMed

Anania, Veronica G; Yu, Kebing; Gnad, Florian; Pferdehirt, Rebecca R; Li, Han; Ma, Taylur P; Jeon, Diana; Fortelny, Nikolaus; Forrest, William; Ashkenazi, Avi; Overall, Christopher M; Lill, Jennie R

2016-07-01

Many diseases are associated with endoplasmic reticulum (ER) stress, which results from an accumulation of misfolded proteins. This triggers an adaptive response called the "unfolded protein response" (UPR), and prolonged exposure to ER stress leads to cell death. Caspases are reported to play a critical role in ER stress-induced cell death but the underlying mechanisms by which they exert their effect continue to remain elusive. To understand the role caspases play during ER stress, a systems level approach integrating analysis of the transcriptome, proteome, and proteolytic substrate profile was employed. This quantitative analysis revealed transcriptional profiles for most human genes, provided information on protein abundance for 4476 proteins, and identified 445 caspase substrates. Based on these data sets many caspase substrates were shown to be downregulated at the protein level during ER stress suggesting caspase activity inhibits their cellular function. Additionally, RNA sequencing revealed a role for caspases in regulation of ER stress-induced transcriptional pathways and gene set enrichment analysis showed expression of multiple gene targets of essential transcription factors to be upregulated during ER stress upon inhibition of caspases. Furthermore, these transcription factors were degraded in a caspase-dependent manner during ER stress. These results indicate that caspases play a dual role in regulating the cellular response to ER stress through both post-translational and transcriptional regulatory mechanisms. Moreover, this study provides unique insight into progression of the unfolded protein response into cell death, which may help identify therapeutic strategies to treat ER stress-related diseases. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Time-Course Transcriptome Analysis Reveals Resistance Genes of Panax ginseng Induced by Cylindrocarpon destructans Infection Using RNA-Seq.

PubMed

Gao, Yuan; He, Xiaoli; Wu, Bin; Long, Qiliang; Shao, Tianwei; Wang, Zi; Wei, Jianhe; Li, Yong; Ding, Wanlong

2016-01-01

Panax ginseng C. A. Meyer is a highly valued medicinal plant. Cylindrocarpon destructans is a destructive pathogen that causes root rot and significantly reduces the quality and yield of P. ginseng. However, an efficient method to control root rot remains unavailable because of insufficient understanding of the molecular mechanism underlying C. destructans-P. ginseng interaction. In this study, C. destructans-induced transcriptomes at different time points were investigated using RNA sequencing (RNA-Seq). De novo assembly produced 73,335 unigenes for the P. ginseng transcriptome after C. destructans infection, in which 3,839 unigenes were up-regulated. Notably, the abundance of the up-regulated unigenes sharply increased at 0.5 d postinoculation to provide effector-triggered immunity. In total, 24 of 26 randomly selected unigenes can be validated using quantitative reverse transcription (qRT)-PCR. Gene ontology enrichment analysis of these unigenes showed that "defense response to fungus", "defense response" and "response to stress" were enriched. In addition, differentially expressed transcription factors involved in the hormone signaling pathways after C. destructans infection were identified. Finally, differentially expressed unigenes involved in reactive oxygen species and ginsenoside biosynthetic pathway during C. destructans infection were indentified. To our knowledge, this study is the first to report on the dynamic transcriptome triggered by C. destructans. These results improve our understanding of disease resistance in P. ginseng and provide a useful resource for quick detection of induced markers in P. ginseng before the comprehensive outbreak of this disease caused by C. destructans.

The MAPKKK gene family in cassava: Genome-wide identification and expression analysis against drought stress.

PubMed

Ye, Jianqiu; Yang, Hai; Shi, Haitao; Wei, Yunxie; Tie, Weiwei; Ding, Zehong; Yan, Yan; Luo, Ying; Xia, Zhiqiang; Wang, Wenquan; Peng, Ming; Li, Kaimian; Zhang, He; Hu, Wei

2017-11-02

Mitogen-activated protein kinase kinase kinases (MAPKKKs), an important unit of MAPK cascade, play crucial roles in plant development and response to various stresses. However, little is known concerning the MAPKKK family in the important subtropical and tropical crop cassava. In this study, 62 MAPKKK genes were identified in the cassava genome, and were classified into 3 subfamilies based on phylogenetic analysis. Most of MAPKKKs in the same subfamily shared similar gene structures and conserved motifs. The comprehensive transcriptome analysis showed that MAPKKK genes participated in tissue development and response to drought stress. Comparative expression profiles revealed that many MAPKKK genes were activated in cultivated varieties SC124 and Arg7 and the function of MeMAPKKKs in drought resistance may be different between SC124/Arg7 and W14. Expression analyses of the 7 selected MeMAPKKK genes showed that most of them were significantly upregulated by osmotic, salt and ABA treatments, whereas slightly induced by H 2 O 2 and cold stresses. Taken together, this study identified candidate MeMAPKKK genes for genetic improvement of abiotic stress resistance and provided new insights into MAPKKK -mediated cassava resistance to drought stress.

Comparative physiological, metabolomic, and transcriptomic analyses reveal mechanisms of improved abiotic stress resistance in bermudagrass [Cynodon dactylon (L). Pers.] by exogenous melatonin

PubMed Central

Shi, Haitao; Jiang, Chuan; Ye, Tiantian; Tan, Dun-xian; Reiter, Russel J.; Zhang, Heng; Liu, Renyi; Chan, Zhulong

2015-01-01

Melatonin (N-acetyl-5-methoxytryptamine), a well-known animal hormone, is also involved in plant development and abiotic stress responses. In this study, it is shown that exogenous application of melatonin conferred improved salt, drought, and cold stress resistances in bermudagrass. Moreover, exogenous melatonin treatment alleviated reactive oxygen species (ROS) burst and cell damage induced by abiotic stress; this involved activation of several antioxidants. Additionally, melatonin-pre-treated plants exhibited higher concentrations of 54 metabolites, including amino acids, organic acids, sugars, and sugar alcohols, than non-treated plants under abiotic stress conditions. Genome-wide transcriptomic profiling identified 3933 transcripts (2361 up-regulated and 1572 down-regulated) that were differentially expressed in melatonin-treated plants versus controls. Pathway and gene ontology (GO) term enrichment analyses revealed that genes involved in nitrogen metabolism, major carbohydrate metabolism, tricarboxylic acid (TCA)/org transformation, transport, hormone metabolism, metal handling, redox, and secondary metabolism were over-represented after melatonin pre-treatment. Taken together, this study provides the first evidence of the protective roles of exogenous melatonin in the bermudagrass response to abiotic stresses, partially via activation of antioxidants and modulation of metabolic homeostasis. Notably, metabolic and transcriptomic analyses showed that the underlying mechanisms of melatonin could involve major reorientation of photorespiratory and carbohydrate and nitrogen metabolism. PMID:25225478

Whole-transcriptome response to water stress in a California endemic oak, Quercus lobata

Treesearch

Paul F. Gugger; Juan Manuel Peñaloza-Ramírez; Jessica W. Wright; Victoria L. Sork; Jörg-Peter Schnitzler

2016-01-01

Reduced water availability during drought can create major stress for many plant species. Within a species, populations with a history of seasonal drought may have evolved the ability to tolerate drought more than those in areas of high precipitation and low seasonality. In this study, we assessed response to water stress in a California oak species, Quercus lobata Née...

Transcriptomic Responses to Salinity Stress in the Pacific Oyster Crassostrea gigas

PubMed Central

Zhao, Xuelin; Yu, Hong; Kong, Lingfeng; Li, Qi

2012-01-01

Background Low salinity is one of the main factors limiting the distribution and survival of marine species. As a euryhaline species, the Pacific oyster Crassostrea gigas is considered to be tolerant to relative low salinity. The genes that regulate C. gigas responses to osmotic stress were monitored using the next-generation sequencing of whole transcriptome with samples taken from gills. By RNAseq technology, transcript catalogs of up- and down-regulated genes were generated from the oysters exposed to low and optimal salinity seawater. Methodology/Principal Findings Through Illumina sequencing, we reported 1665 up-regulated transcripts and 1815 down-regulated transcripts. A total of 45771 protein-coding contigs were identified from two groups based on sequence similarities with known proteins. As determined by GO annotation and KEGG pathway mapping, functional annotation of the genes recovered diverse biological functions and processes. The genes that changed expression significantly were highly represented in cellular process and regulation of biological process, intracellular and cell, binding and protein binding according to GO annotation. The results highlighted genes related to osmoregulation, signaling and interactions of osmotic stress response, anti-apoptotic reactions as well as immune response, cell adhesion and communication, cytoskeleton and cell cycle. Conclusions/Significance Through more than 1.5 million sequence reads and the expression data of the two libraries, the study provided some useful insights into signal transduction pathways in oysters and offered a number of candidate genes as potential markers of tolerance to hypoosmotic stress for oysters. In addition, the characterization of C. gigas transcriptome will not only provide a better understanding of the molecular mechanisms about the response to osmotic stress of the oysters, but also facilitate research into biological processes to find underlying physiological adaptations to hypoosmotic shock for marine invertebrates. PMID:23029449

Analysis of Transcriptomic Dose Response Data in the ...

EPA Pesticide Factsheets

Slide presentation at the HESI-HEALTH Canada-McGill Workshop on Transcriptomic Dose Response Data in the Context of Chemical Risk Assessment Slide presentation at the HESI-HEALTH Canada-McGill Workshop on Transcriptomic Dose Response Data in the Context of Chemical Risk Assessment

Hydrogen-peroxide-induced oxidative stress responses in Desulfovibrio vulgaris Hildenborough

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, A.; He, Z.; Redding-Johanson, A.M.

2010-07-01

To understand how sulphate-reducing bacteria respond to oxidative stresses, the responses of Desulfovibrio vulgaris Hildenborough to H{sub 2}O{sub 2}-induced stresses were investigated with transcriptomic, proteomic and genetic approaches. H{sub 2}O{sub 2} and induced chemical species (e.g. polysulfide, ROS) and redox potential shift increased the expressions of the genes involved in detoxification, thioredoxin-dependent reduction system, protein and DNA repair, and decreased those involved in sulfate reduction, lactate oxidation and protein synthesis. A gene coexpression network analysis revealed complicated network interactions among differentially expressed genes, and suggested possible importance of several hypothetical genes in H{sub 2}O{sub 2} stress. Also, most of themore » genes in PerR and Fur regulons were highly induced, and the abundance of a Fur regulon protein increased. Mutant analysis suggested that PerR and Fur are functionally overlapped in response to stresses induced by H{sub 2}O{sub 2} and reaction products, and the upregulation of thioredoxin-dependent reduction genes was independent of PerR or Fur. It appears that induction of those stress response genes could contribute to the increased resistance of deletion mutants to H{sub 2}O{sub 2}-induced stresses. In addition, a conceptual cellular model of D. vulgaris responses to H{sub 2}O{sub 2} stress was constructed to illustrate that this bacterium may employ a complicated molecular mechanism to defend against the H{sub 2}O{sub 2}-induced stresses.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sardi, Maria; Rovinskiy, Nikolay; Zhang, Yaoping

We report a major obstacle to sustainable lignocellulosic biofuel production is microbe inhibition by the combinatorial stresses in pretreated plant hydrolysate. Chemical biomass pretreatment releases a suite of toxins that interact with other stressors, including high osmolarity and temperature, which together can have poorly understood synergistic effects on cells. Improving tolerance in industrial strains has been hindered, in part because the mechanisms of tolerance reported in the literature often fail to recapitulate in other strain backgrounds. Here, we explored and then exploited variations in stress tolerance, toxin-induced transcriptomic responses, and fitness effects of gene overexpression in different Saccharomyces cerevisiae (yeast)more » strains to identify genes and processes linked to tolerance of hydrolysate stressors. Using six different S. cerevisiae strains that together maximized phenotypic and genetic diversity, first we explored transcriptomic differences between resistant and sensitive strains to identify common and strain-specific responses. This comparative analysis implicated primary cellular targets of hydrolysate toxins, secondary effects of defective defense strategies, and mechanisms of tolerance. Dissecting the responses to individual hydrolysate components across strains pointed to synergistic interactions between osmolarity, pH, hydrolysate toxins, and nutrient composition. By characterizing the effects of high-copy gene overexpression in three different strains, we revealed the breadth of the background-specific effects of gene fitness contributions in synthetic hydrolysate. Lastly, our approach identified new genes for engineering improved stress tolerance in diverse strains while illuminating the effects of genetic background on molecular mechanisms.« less

Transcriptome profiling analysis reveals the role of latrophilin in controlling development, reproduction and insecticide susceptibility in Tribolium castaneum.

PubMed

Gao, Shanshan; Xiong, Wenfeng; Wei, Luting; Liu, Juanjuan; Liu, Xing; Xie, Jia; Song, Xiaowen; Bi, Jingxiu; Li, Bin

2018-06-01

Latrophilin of Tribolium castaneum (Tclph) has been reported to play crucial roles in growth, development and reproduction. However, the regulatory mechanism of Tclph associated with these physiology processes is unknown. Thus, the global transcriptome profiles between RNAi treated (ds-Tclph) and control larvae of T. castaneum were analyzed by RNA-sequencing. Totally, 274 differentially expressed genes (DEGs) were identified between the ds-Tclph and control samples. These DEGs were classified into 42 GO functional groups, including developmental process, reproduction and stress response. The results indicated that knockdown of Tclph disturbed the antioxidant activity process, and partially inhibited the serine protease (SP) and lipase signaling pathways to regulate the development and reproduction as well as the decreasing of the stress response in T. castaneum. Additionally, knockdown of Tclph suppressed IMD immunity pathways which likely modulated the effects of Tclph on stress response. Interestingly, CSPs, ESTs, CYPs, AOXs and BGs were significantly down-regulated in ds-Tclph larvae, implying that they cooperated with Tclph to reduce the activity of cellular metabolism system. FMOs was up-regulated in ds-Tclph insects suggested it may be involved in detoxifying alkaloid of insect metabolism system. These results implied that Tclph participated in phase 0, I and II cellular detoxification. Furthermore, RNAi against Tclph increased larval susceptibility to carbamates and organophosphates insecticides, supporting that Tclph was indeed involved into the insecticide susceptibility in T. castaneum.

Comparative transcriptome analysis of duckweed (Landoltia punctata) in response to cadmium provides insights into molecular mechanisms underlying hyperaccumulation.

PubMed

Xu, Hua; Yu, Changjiang; Xia, Xinli; Li, Mingliang; Li, Huiguang; Wang, Yu; Wang, Shumin; Wang, Congpeng; Ma, Yubin; Zhou, Gongke

2018-01-01

Cadmium (Cd) is a detrimental environmental pollutant. Duckweeds have been considered promising candidates for Cd phytoremediation. Although many physiological studies have been conducted, the molecular mechanisms underlying Cd hyperaccumulation in duckweeds are largely unknown. In this study, clone 6001 of Landoltia punctata, which showed high Cd tolerance, was obtained by large-scale screening of over 200 duckweed clones. Subsequently, its growth, Cd flux, Cd accumulation, and Cd distribution characteristics were investigated. To further explore the global molecular mechanism, a comprehensive transcriptome analysis was performed. For RNA-Seq, samples were treated with 20 μM CdCl 2 for 0, 1, 3, and 6 days. In total, 9,461, 9,847, and 9615 differentially expressed unigenes (DEGs) were discovered between Cd-treated and control (0 day) samples. DEG clustering and enrichment analysis identified several biological processes for coping with Cd stress. Genes involved in DNA repair acted as an early response to Cd, while RNA and protein metabolism would be likely to respond as well. Furthermore, the carbohydrate metabolic flux tended to be modulated in response to Cd stress, and upregulated genes involved in sulfur and ROS metabolism might cause high Cd tolerance. Vacuolar sequestration most likely played an important role in Cd detoxification in L. punctata 6001. These novel findings provided important clues for molecular assisted screening and breeding of Cd hyperaccumulating cultivars for phytoremediation. Copyright © 2017 Elsevier Ltd. All rights reserved.

RNA-Seq and Gene Network Analysis Uncover Activation of an ABA-Dependent Signalosome During the Cork Oak Root Response to Drought

PubMed Central

Magalhães, Alexandre P.; Verde, Nuno; Reis, Francisca; Martins, Inês; Costa, Daniela; Lino-Neto, Teresa; Castro, Pedro H.; Tavares, Rui M.; Azevedo, Herlânder

2016-01-01

Quercus suber (cork oak) is a West Mediterranean species of key economic interest, being extensively explored for its ability to generate cork. Like other Mediterranean plants, Q. suber is significantly threatened by climatic changes, imposing the need to quickly understand its physiological and molecular adaptability to drought stress imposition. In the present report, we uncovered the differential transcriptome of Q. suber roots exposed to long-term drought, using an RNA-Seq approach. 454-sequencing reads were used to de novo assemble a reference transcriptome, and mapping of reads allowed the identification of 546 differentially expressed unigenes. These were enriched in both effector genes (e.g., LEA, chaperones, transporters) as well as regulatory genes, including transcription factors (TFs) belonging to various different classes, and genes associated with protein turnover. To further extend functional characterization, we identified the orthologs of differentially expressed unigenes in the model species Arabidopsis thaliana, which then allowed us to perform in silico functional inference, including gene network analysis for protein function, protein subcellular localization and gene co-expression, and in silico enrichment analysis for TFs and cis-elements. Results indicated the existence of extensive transcriptional regulatory events, including activation of ABA-responsive genes and ABF-dependent signaling. We were then able to establish that a core ABA-signaling pathway involving PP2C-SnRK2-ABF components was induced in stressed Q. suber roots, identifying a key mechanism in this species’ response to drought. PMID:26793200

Temporal transcriptome changes induced by methyl jasmonate in Salvia sclarea.

PubMed

Hao, Da Cheng; Chen, Shi Lin; Osbourn, Anne; Kontogianni, Vassiliki G; Liu, Li Wei; Jordán, Maria J

2015-03-01

Salvia sclarea is a traditional medicinal and aromatic plant that grows in Europe and produces various economically important compounds, including phenylpropanoid derivatives and terpenoids. Methyl jasmonate (MeJA) is commonly used to elicit plant stress responses. However, how MeJA enhances production of secondary metabolites in S. sclarea is not well understood. We performed a genome-wide analysis of temporal gene expression in S. sclarea leaves and roots. The transcriptome profiles 0, 10 and 26 h after MeJA treatment were analyzed by Illumina RNA-Seq. A total of 16,142 isogenes (average length 866bp; N50 1035bp) were obtained by de novo assembly of 35,757,567 raw sequencing reads. When these sequencing reads were mapped onto the assembled Unigenes, 3236, 2792 and 798 Unigenes were found to be expressed differentially between 0 and 10h, 0 and 26 h, and 10 and 26h, respectively. These included many secondary metabolite biosynthesis, stress and defense-related genes. A qRT-PCR analysis confirmed the expression profiles of selected differentially expressed genes (DEGs) revealed by RNA-Seq data, and also extended our analysis of differential gene expression to 73 h. Our investigations revealed temporal differences in the responses of S. sclarea to MeJA treatment. MeJA treatment induced the expression of a large number of genes involved in phenylpropanoid biosynthesis, especially between 0 and 10h, and 0 and 26 h. Additionally, many genes encoding transcription factors, cytochrome P450s, glycosyltransferases, methyltransferases and transporters were shown to respond to MeJA elicitation. DEGs related to structural molecule activity and cell death showed a significant temporal variation. A chromatographic analysis of metabolites at 26h, 73h and six days after MeJA treatment indicated that these transcriptomic changes precede MeJA-induced changes in secondary metabolite content. This study sheds light on the molecular mechanisms of MeJA elicitation and is helpful in understanding how exogenous MeJA treatment mediates extensive plant transcriptome reprogramming/remodeling. Our results can be utilized to characterize genes related to secondary metabolism and their regulation, and in breeding S. sclarea for desirable chemotypes. Copyright © 2014 Elsevier B.V. All rights reserved.

Transcriptome Analysis of Kiwifruit (Actinidia chinensis) Bark in Response to Armoured Scale Insect (Hemiberlesia lataniae) Feeding

PubMed Central

Hill, M. Garry; Wurms, Kirstin V.; Davy, Marcus W.; Gould, Elaine; Allan, Andrew; Mauchline, Nicola A.; Luo, Zhiwei; Ah Chee, Annette; Stannard, Kate; Storey, Roy D.; Rikkerink, Erik H.

2015-01-01

The kiwifruit cultivar Actinidia chinensis ‘Hort16A’ is resistant to the polyphagous armoured scale insect pest Hemiberlesia lataniae (Hemiptera: Diaspididae). A cDNA microarray consisting of 17,512 unigenes selected from over 132,000 expressed sequence tags (ESTs) was used to measure the transcriptomic profile of the A. chinensis ‘Hort16A’ canes in response to a controlled infestation of H. lataniae. After 2 days, 272 transcripts were differentially expressed. After 7 days, 5,284 (30%) transcripts were differentially expressed. The transcripts were grouped into 22 major functional categories using MapMan software. After 7 days, transcripts associated with photosynthesis (photosystem II) were significantly down-regulated, while those associated with secondary metabolism were significantly up-regulated. A total of 643 transcripts associated with response to stress were differentially expressed. This included biotic stress-related transcripts orthologous with pathogenesis related proteins, the phenylpropanoid pathway, NBS-LRR (R) genes, and receptor-like kinase–leucine rich repeat signalling proteins. While transcriptional studies are not conclusive in their own right, results were suggestive of a defence response involving both ETI and PTI, with predominance of the SA signalling pathway. Exogenous application of an SA-mimic decreased H. lataniae growth on A. chinensis ‘Hort16A’ plants in two laboratory experiments. PMID:26571404

Flower bud transcriptome analysis of Sapium sebiferum (Linn.) Roxb. and primary investigation of drought induced flowering: pathway construction and G-quadruplex prediction based on transcriptome.

PubMed

Yang, Minglei; Wu, Ying; Jin, Shan; Hou, Jinyan; Mao, Yingji; Liu, Wenbo; Shen, Yangcheng; Wu, Lifang

2015-01-01

Sapium sebiferum (Linn.) Roxb. (Chinese Tallow Tree) is a perennial woody tree and its seeds are rich in oil which hold great potential for biodiesel production. Despite a traditional woody oil plant, our understanding on S. sebiferum genetics and molecular biology remains scant. In this study, the first comprehensive transcriptome of S. sebiferum flower has been generated by sequencing and de novo assembly. A total of 149,342 unigenes were generated from raw reads, of which 24,289 unigenes were successfully matched to public database. A total of 61 MADS box genes and putative pathways involved in S. sebiferum flower development have been identified. Abiotic stress response network was also constructed in this work, where 2,686 unigenes are involved in the pathway. As for lipid biosynthesis, 161 unigenes have been identified in fatty acid (FA) and triacylglycerol (TAG) biosynthesis. Besides, the G-Quadruplexes in RNA of S. sebiferum also have been predicted. An interesting finding is that the stress-induced flowering was observed in S. sebiferum for the first time. According to the results of semi-quantitative PCR, expression tendencies of flowering-related genes, GA1, AP2 and CRY2, accorded with stress-related genes, such as GRX50435 and PRXⅡ39562. This transcriptome provides functional genomic information for further research of S. sebiferum, especially for the genetic engineering to shorten the juvenile period and improve yield by regulating flower development. It also offers a useful database for the research of other Euphorbiaceae family plants.

Hepatic Transcriptome Responses in Mice (Mus musculus) Exposed to the Nafion Membrane and Its Combustion Products

PubMed Central

Feng, Mingbao; Qu, Ruijuan; Habteselassie, Mussie; Wu, Jun; Yang, Shaogui; Sun, Ping; Huang, Qingguo; Wang, Zunyao

2015-01-01

Nafion 117 membrane (N117), an important polymer electrolyte membrane (PEM), has been widely used for numerous chemical technologies. Despite its increasing production and use, the toxicity data for N117 and its combustion products remain lacking. Toxicity studies are necessary to avoid problems related to waste disposal in landfills and incineration that may arise. In this study, we investigated the histopathological alterations, oxidative stress biomarker responses, and transcriptome profiles in the liver of male mice exposed to N117 and its combustion products for 24 days. An ion-chromatography system and liquid chromatography system coupled to a hybrid quadrupole time-of-flight mass spectrometry were used to analyze the chemical compositions of these combustion products. The transcriptomics analysis identified several significantly altered molecular pathways, including the metabolism of xenobiotics, carbohydrates and lipids; signal transduction; cellular processes; immune system; and signaling molecules and interaction. These studies provide preliminary data for the potential toxicity of N117 and its combustion products on living organisms and may fill the information gaps in the toxicity databases for the currently used PEMs. PMID:26057616

Impact of Heat Stress on Cellular and Transcriptional Adaptation of Mammary Epithelial Cells in Riverine Buffalo (Bubalus Bubalis)

PubMed Central

Kapila, Neha; Sharma, Ankita; Kishore, Amit; Sodhi, Monika; Tripathi, Pawan K.; Mohanty, Ashok K.

2016-01-01

The present study aims to identify the heat responsive genes and biological pathways in heat stressed buffalo mammary epithelial cells (MECs). The primary mammary epithelial cells of riverine buffalo were exposed to thermal stress at 42°C for one hour. The cells were subsequently allowed to recover at 37°C and harvested at different time intervals (30 min to 48 h) along with control samples (un-stressed). In order to assess the impact of heat stress in buffalo MECs, several in-vitro cellular parameters (lactate dehydrogenase activity, cell proliferation assay, cellular viability, cell death and apoptosis) and transcriptional studies were conducted. The heat stress resulted in overall decrease in cell viability and cell proliferation of MECs while induction of cellular apoptosis and necrosis. The transcriptomic profile of heat stressed MECs was generated using Agilent 44 K bovine oligonucleotide array and at cutoff criteria of ≥3-or ≤3 fold change, a total of 153 genes were observed to be upregulated while 8 genes were down regulated across all time points post heat stress. The genes that were specifically up-regulated or down-regulated were identified as heat responsive genes. The upregulated genes in heat stressed MECs belonged to heat shock family viz., HSPA6, HSPB8, DNAJB2, HSPA1A. Along with HSPs, genes like BOLA, MRPL55, PFKFB3, PSMC2, ENDODD1, ARID5A, and SENP3 were also upregulated. Microarray data revealed that the heat responsive genes belonged to different functional classes viz., chaperons; immune responsive; cell proliferation and metabolism related. Gene ontology analysis revealed enrichment of several biological processes like; cellular process, metabolic process, response to stimulus, biological regulation, immune system processes and signaling. The transcriptome analysis data was further validated by RT-qPCR studies. Several HSP (HSP40, HSP60, HSP70, HSP90, and HSPB1), apoptotic (Bax and Bcl2), immune (IL6, TNFα and NF-kβ) and oxidative stress (GPX1 and DUSP1) related genes showed differential expression profile at different time points post heat stress. The transcriptional data strongly indicated the induction of survival/apoptotic mechanism in heat stressed buffalo MECs. The overrepresented pathways across all time points were; electron transport chain, cytochrome P450, apoptosis, MAPK, FAS and stress induction of HSP regulation, delta Notch signaling, apoptosis modulation by HSP70, EGFR1 signaling, cytokines and inflammatory response, oxidative stress, TNF-alpha and NF- kB signaling pathway. The study thus identified several genes from different functional classes and biological pathways that could be termed as heat responsive in buffalo MEC. The responsiveness of buffalo MECs to heat stress in the present study clearly suggested its suitability as a model to understand the modulation of buffalo mammary gland expression signature in response to environmental heat load. PMID:27682256

Genomic, transcriptomic, and proteomic approaches towards understanding the molecular mechanisms of salt tolerance in Frankia strains isolated from Casuarina trees.

PubMed

Oshone, Rediet; Ngom, Mariama; Chu, Feixia; Mansour, Samira; Sy, Mame Ourèye; Champion, Antony; Tisa, Louis S

2017-08-18

Soil salinization is a worldwide problem that is intensifying because of the effects of climate change. An effective method for the reclamation of salt-affected soils involves initiating plant succession using fast growing, nitrogen fixing actinorhizal trees such as the Casuarina. The salt tolerance of Casuarina is enhanced by the nitrogen-fixing symbiosis that they form with the actinobacterium Frankia. Identification and molecular characterization of salt-tolerant Casuarina species and associated Frankia is imperative for the successful utilization of Casuarina trees in saline soil reclamation efforts. In this study, salt-tolerant and salt-sensitive Casuarina associated Frankia strains were identified and comparative genomics, transcriptome profiling, and proteomics were employed to elucidate the molecular mechanisms of salt and osmotic stress tolerance. Salt-tolerant Frankia strains (CcI6 and Allo2) that could withstand up to 1000 mM NaCl and a salt-sensitive Frankia strain (CcI3) which could withstand only up to 475 mM NaCl were identified. The remaining isolates had intermediate levels of salt tolerance with MIC values ranging from 650 mM to 750 mM. Comparative genomic analysis showed that all of the Frankia isolates from Casuarina belonged to the same species (Frankia casuarinae). Pangenome analysis revealed a high abundance of singletons among all Casuarina isolates. The two salt-tolerant strains contained 153 shared single copy genes (most of which code for hypothetical proteins) that were not found in the salt-sensitive(CcI3) and moderately salt-tolerant (CeD) strains. RNA-seq analysis of one of the two salt-tolerant strains (Frankia sp. strain CcI6) revealed hundreds of genes differentially expressed under salt and/or osmotic stress. Among the 153 genes, 7 and 7 were responsive to salt and osmotic stress, respectively. Proteomic profiling confirmed the transcriptome results and identified 19 and 8 salt and/or osmotic stress-responsive proteins in the salt-tolerant (CcI6) and the salt-sensitive (CcI3) strains, respectively. Genetic differences between salt-tolerant and salt-sensitive Frankia strains isolated from Casuarina were identified. Transcriptome and proteome profiling of a salt-tolerant strain was used to determine molecular differences correlated with differential salt-tolerance and several candidate genes were identified. Mechanisms involving transcriptional and translational regulation, cell envelop remodeling, and previously uncharacterized proteins appear to be important for salt tolerance. Physiological and mutational analyses will further shed light on the molecular mechanism of salt tolerance in Casuarina associated Frankia isolates.

Transcriptome analysis shows activation of the arginine deiminase pathway in Lactococcus lactis as a response to ethanol stress.

PubMed

Díez, Lorena; Solopova, Ana; Fernández-Pérez, Rocío; González, Miriam; Tenorio, Carmen; Kuipers, Oscar P; Ruiz-Larrea, Fernanda

2017-09-18

This paper describes the molecular response of Lactococcus lactis NZ9700 to ethanol. This strain is a well-known nisin producer and a lactic acid bacteria (LAB) model strain. Global transcriptome profiling using DNA microarrays demonstrated a bacterial adaptive response to the presence of 2% ethanol in the culture broth and differential expression of 67 genes. The highest up-regulation was detected for those genes involved in arginine degradation through the arginine deiminase (ADI) pathway (20-40 fold up-regulation). The metabolic responses to ethanol of wild type L. lactis strains were studied and compared to those of regulator-deletion mutants MG∆argR and MG∆ahrC. The results showed that in the presence of 2% ethanol those strains with an active ADI pathway reached higher growth rates when arginine was available in the culture broth than in absence of arginine. In a chemically defined medium strains with an active ADI pathway consumed arginine and produced ornithine in the presence of 2% ethanol, hence corroborating that arginine catabolism is involved in the bacterial response to ethanol. This is the first study of the L. lactis response to ethanol stress to demonstrate the relevance of arginine catabolism for bacterial adaptation and survival in an ethanol containing medium. Copyright © 2017 Elsevier B.V. All rights reserved.

Tissue-Specific Transcriptomics Reveals an Important Role of the Unfolded Protein Response in Maintaining Fertility upon Heat Stress in Arabidopsis

PubMed Central

Zhang, Shuang-Shuang; Yang, Hongxing; Ding, Lan; Song, Ze-Ting; Ma, Hong; Chang, Fang

2017-01-01

High temperatures have a great impact on plant reproductive development and subsequent fruit and seed set, but the underlying molecular mechanisms are not well understood. We used transcriptome profiling to investigate the effect of heat stress on reproductive development of Arabidopsis thaliana plants and observed distinct response patterns in vegetative versus reproductive tissues. Exposure to heat stress affected reproductive developmental programs, including early phases of anther/ovule development and meiosis. Also, genes participating in the unfolded protein response (UPR) were enriched in the reproductive tissue-specific genes that were upregulated by heat. Moreover, we found that the UPR-deficient bzip28 bzip60 double mutant was sensitive to heat stresses and had reduced silique length and fertility. Comparison of heat-responsive wild type versus bzip28 bzip60 plants identified 521 genes that were regulated by bZIP28 and bZIP60 upon heat stress during reproductive stages, most of which were noncanonical UPR genes. Chromatin immunoprecipitation coupled with high-throughput sequencing analyses revealed 133 likely direct targets of bZIP28 in Arabidopsis seedlings subjected to heat stress, including 27 genes that were also upregulated by heat during reproductive development. Our results provide important insights into heat responsiveness in Arabidopsis reproductive tissues and demonstrate the protective roles of the UPR for maintaining fertility upon heat stress. PMID:28442596

Global Transcriptome and Deletome Profiles of Yeast Exposed to Transition Metals

PubMed Central

Jin, Yong Hwan; Dunlap, Paul E.; McBride, Sandra J.; Al-Refai, Hanan; Bushel, Pierre R.; Freedman, Jonathan H.

2008-01-01

A variety of pathologies are associated with exposure to supraphysiological concentrations of essential metals and to non-essential metals and metalloids. The molecular mechanisms linking metal exposure to human pathologies have not been clearly defined. To address these gaps in our understanding of the molecular biology of transition metals, the genomic effects of exposure to Group IB (copper, silver), IIB (zinc, cadmium, mercury), VIA (chromium), and VB (arsenic) elements on the yeast Saccharomyces cerevisiae were examined. Two comprehensive sets of metal-responsive genomic profiles were generated following exposure to equi-toxic concentrations of metal: one that provides information on the transcriptional changes associated with metal exposure (transcriptome), and a second that provides information on the relationship between the expression of ∼4,700 non-essential genes and sensitivity to metal exposure (deletome). Approximately 22% of the genome was affected by exposure to at least one metal. Principal component and cluster analyses suggest that the chemical properties of the metal are major determinants in defining the expression profile. Furthermore, cells may have developed common or convergent regulatory mechanisms to accommodate metal exposure. The transcriptome and deletome had 22 genes in common, however, comparison between Gene Ontology biological processes for the two gene sets revealed that metal stress adaptation and detoxification categories were commonly enriched. Analysis of the transcriptome and deletome identified several evolutionarily conserved, signal transduction pathways that may be involved in regulating the responses to metal exposure. In this study, we identified genes and cognate signaling pathways that respond to exposure to essential and non-essential metals. In addition, genes that are essential for survival in the presence of these metals were identified. This information will contribute to our understanding of the molecular mechanism by which organisms respond to metal stress, and could lead to an understanding of the connection between environmental stress and signal transduction pathways. PMID:18437200

Comparative transcriptome analysis reveals insights into the streamlined genomes of haplosclerid demosponges

NASA Astrophysics Data System (ADS)

Guzman, Christine; Conaco, Cecilia

2016-01-01

Sponges (Porifera) are one of the most ancestral metazoan groups. They are characterized by a simple body plan lacking the true tissues and organ systems found in other animals. Members of this phylum display a remarkable diversity of form and function and yet little is known about the composition and complexity of their genomes. In this study, we sequenced the transcriptomes of two marine haplosclerid sponges belonging to Demospongiae, the largest and most diverse class within phylum Porifera, and compared their gene content with members of other sponge classes. We recovered 44,693 and 50,067 transcripts expressed in adult tissues of Haliclona amboinensis and Haliclona tubifera, respectively. These transcripts translate into 20,280 peptides in H. amboinensis and 18,000 peptides in H. tubifera. Genes associated with important signaling and metabolic pathways, regulatory networks, as well as genes that may be important in the organismal stress response, were identified in the transcriptomes. Futhermore, lineage-specific innovations were identified that may be correlated with observed sponge characters and ecological adaptations. The core gene complement expressed within the tissues of adult haplosclerid demosponges may represent a streamlined and flexible genetic toolkit that underlies the ecological success and resilience of sponges to environmental stress.

Dehydration induced transcriptomic responses in two Tibetan hulless barley (Hordeum vulgare var. nudum) accessions distinguished by drought tolerance.

PubMed

Liang, Junjun; Chen, Xin; Deng, Guangbing; Pan, Zhifen; Zhang, Haili; Li, Qiao; Yang, Kaijun; Long, Hai; Yu, Maoqun

2017-10-11

The harsh environment on the Qinghai-Tibetan Plateau gives Tibetan hulless barley (Hordeum vulgare var. nudum) great ability to resist adversities such as drought, salinity, and low temperature, and makes it a good subject for the analysis of drought tolerance mechanism. To elucidate the specific gene networks and pathways that contribute to its drought tolerance, and for identifying new candidate genes for breeding purposes, we performed a transcriptomic analysis using two accessions of Tibetan hulless barley, namely Z772 (drought-tolerant) and Z013 (drought-sensitive). There were more up-regulated genes of Z772 than Z013 under both mild (5439-VS-2604) and severe (7203-VS-3359) dehydration treatments. Under mild dehydration stress, the pathways exclusively enriched in drought-tolerance genotype Z772 included Protein processing in endoplasmic reticulum, tricarboxylic acid (TCA) cycle, Wax biosynthesis, and Spliceosome. Under severe dehydration stress, the pathways that were mainly enriched in Z772 included Carbon fixation in photosynthetic organisms, Pyruvate metabolism, Porphyrin and chlorophyll metabolism. The main differentially expressed genes (DEGs) in response to dehydration stress and genes whose expression was different between tolerant and sensitive genotypes were presented in this study, respectively. The candidate genes for drought tolerance were selected based on their expression patterns. The RNA-Seq data obtained in this study provided an initial overview on global gene expression patterns and networks that related to dehydration shock in Tibetan hulless barley. Furthermore, these data provided pathways and a targeted set of candidate genes that might be essential for deep analyzing the molecular mechanisms of plant tolerance to drought stress.

Physiological and transcriptomic analyses reveal a response mechanism to cold stress in Santalum album L. leaves

PubMed Central

Zhang, Xinhua; Teixeira da Silva, Jaime A.; Niu, Meiyun; Li, Mingzhi; He, Chunmei; Zhao, Jinhui; Zeng, Songjun; Duan, Jun; Ma, Guohua

2017-01-01

Santalum album L. (Indian sandalwood) is an economically important plant species because of its ability to produce highly valued perfume oils. Little is known about the mechanisms by which S. album adapts to low temperatures. In this study, we obtained 100,445,724 raw reads by paired-end sequencing from S. album leaves. Physiological and transcriptomic changes in sandalwood seedlings exposed to 4 °C for 0–48 h were characterized. Cold stress induced the accumulation of malondialdehyde, proline and soluble carbohydrates, and increased the levels of antioxidants. A total of 4,424 differentially expressed genes were responsive to cold, including 3,075 cold-induced and 1,349 cold-repressed genes. When cold stress was prolonged, there was an increase in the expression of cold-responsive genes coding for transporters, responses to stimuli and stress, regulation of defense response, as well as genes related to signal transduction of all phytohormones. Candidate genes in the terpenoid biosynthetic pathway were identified, eight of which were significantly involved in the cold stress response. Gene expression analyses using qRT-PCR showed a peak in the accumulation of SaCBF2 to 4, 50-fold more than control leaves and roots following 12 h and 24 h of cold stress, respectively. The CBF-dependent pathway may play a crucial role in increasing cold tolerance. PMID:28169358

The rehydration transcriptome of the desiccation-tolerant bryophyte Tortula ruralis: transcript classification and analysis

PubMed Central

Oliver, Melvin J; Dowd, Scot E; Zaragoza, Joaquin; Mauget, Steven A; Payton, Paxton R

2004-01-01

Background The cellular response of plants to water-deficits has both economic and evolutionary importance directly affecting plant productivity in agriculture and plant survival in the natural environment. Genes induced by water-deficit stress have been successfully enumerated in plants that are relatively sensitive to cellular dehydration, however we have little knowledge as to the adaptive role of these genes in establishing tolerance to water loss at the cellular level. Our approach to address this problem has been to investigate the genetic responses of plants that are capable of tolerating extremes of dehydration, in particular the desiccation-tolerant bryophyte, Tortula ruralis. To establish a sound basis for characterizing the Tortula genome in regards to desiccation tolerance, we analyzed 10,368 expressed sequence tags (ESTs) from rehydrated rapid-dried Tortula gametophytes, a stage previously determined to exhibit the maximum stress induced change in gene expression. Results The 10, 368 ESTs formed 5,563 EST clusters (contig groups representing individual genes) of which 3,321 (59.7%) exhibited similarity to genes present in the public databases and 2,242 were categorized as unknowns based on protein homology scores. The 3,321 clusters were classified by function using the Gene Ontology (GO) hierarchy and the KEGG database. The results indicate that the transcriptome contains a diverse population of transcripts that reflects, as expected, a period of metabolic upheaval in the gametophyte cells. Much of the emphasis within the transcriptome is centered on the protein synthetic machinery, ion and metabolite transport, and membrane biosynthesis and repair. Rehydrating gametophytes also have an abundance of transcripts that code for enzymes involved in oxidative stress metabolism and phosphorylating activities. The functional classifications reflect a remarkable consistency with what we have previously established with regards to the metabolic activities that are important in the recovery of the gametophytes from desiccation. A comparison of the GO distribution of Tortula clusters with an identical analysis of 9,981 clusters from the desiccation sensitive bryophyte species Physcomitrella patens, revealed, and accentuated, the differences between stressed and unstressed transcriptomes. Cross species sequence comparisons indicated that on the whole the Tortula clusters were more closely related to those from Physcomitrella than Arabidopsis (complete genome BLASTx comparison) although because of the differences in the databases there were more high scoring matches to the Arabidopsis sequences. The most abundant transcripts contained within the Tortula ESTs encode Late Embryogenesis Abundant (LEA) proteins that are normally associated with drying plant tissues. This suggests that LEAs may also play a role in recovery from desiccation when water is reintroduced into a dried tissue. Conclusion The establishment of a rehydration EST collection for Tortula ruralis, an important plant model for plant stress responses and vegetative desiccation tolerance, is an important step in understanding the genome level response to cellular dehydration. The type of transcript analysis performed here has laid the foundation for more detailed functional and genome level analyses of the genes involved in desiccation tolerance in plants. PMID:15546486

Responses of grapevine rootstocks to drought through altered root system architecture and root transcriptomic regulations.

PubMed

Yıldırım, Kubilay; Yağcı, Adem; Sucu, Seda; Tunç, Sümeyye

2018-06-01

Roots are the major interface between the plant and various stress factors in the soil environment. Alteration of root system architecture (RSA) (root length, spread, number and length of lateral roots) in response to environmental changes is known to be an important strategy for plant adaptation and productivity. In light of ongoing climate changes and global warming predictions, the breeding of drought-tolerant grapevine cultivars is becoming a crucial factor for developing a sustainable viticulture. Root-trait modeling of grapevine rootstock for drought stress scenarios, together with high-throughput phenotyping and genotyping techniques, may provide a valuable background for breeding studies in viticulture. Here, tree grafted grapevine rootstocks (110R, 5BB and 41B) having differential RSA regulations and drought tolerance were investigated to define their drought dependent root characteristics. Root area, root length, ramification and number of root tips reduced less in 110R grafted grapevines compared to 5BB and 41B grafted ones during drought treatment. Root relative water content as well as total carbohydrate and nitrogen content were found to be much higher in the roots of 110R than it was in the roots of other rootstocks under drought. Microarray-based root transcriptome profiling was also conducted on the roots of these rootstocks to identify their gene regulation network behind drought-dependent RSA alterations. Transcriptome analysis revealed totally 2795, 1196 and 1612 differentially expressed transcripts at the severe drought for the roots of 110R, 5BB and 41B, respectively. According to this transcriptomic data, effective root elongation and enlargement performance of 110R were suggested to depend on three transcriptomic regulations. First one is the drought-dependent induction in sugar and protein transporters genes (SWEET and NRT1/PTR) in the roots of 110R to facilitate carbohydrate and nitrogen accumulation. In the roots of the same rootstock, expression increase in osmolyte producer genes revealed another transcriptomic regulation enabling effective root osmotic adjustment under drought stress. The third mechanism was linked to root suberization with upregulation of transcripts functional in wax producing enzymes (Caffeic acid 3-O-methyltransferase, Eceriferum3, 3-ketoacyl-CoAsynthase). These three transcriptomic regulations were suggested to provide essential energy and water preservation to the roots of 110R for its effective RSA regulation under drought. This phenotypic and genotypic knowledge could be used to develop root-dependent drought tolerant grapevines in breeding programs and could facilitate elucidation of genetic regulations behind RSA alteration in other plants. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Comparative transcriptome profiling of a thermal resistant vs. sensitive silkworm strain in response to high temperature under stressful humidity condition

PubMed Central

Xiao, Jinshu; Wang, La; Liu, Taihang; Wu, Yunfei; Dong, Feifan; Jiang, Yaming; Pan, Minhui; Zhang, Youhong; Lu, Cheng

2017-01-01

Thermotolerance is important particularly for poikilotherms such as insects. Understanding the mechanisms by which insects respond to high temperatures can provide insights into their adaptation to the environment. Therefore, in this study, we performed a transcriptome analysis of two silkworm strains with significantly different resistance to heat as well as humidity; the thermo-resistant strain 7532 and the thermos-sensitive strain Knobbed. We identified in total 4,944 differentially expressed genes (DEGs) using RNA-Seq. Among these, 4,390 were annotated and 554 were novel. Gene Ontology (GO) analysis of 747 DEGs identified between RT_48h (Resistant strain with high-temperature Treatment for 48 hours) and ST_48h (Sensitive strain with high-temperature Treatment for 48 hours) showed significant enrichment of 12 GO terms including metabolic process, extracellular region and serine-type peptidase activity. Moreover, we discovered 12 DEGs that may contribute to the heat-humidity stress response in the silkworm. Our data clearly showed that 48h post-exposure may be a critical time point for silkworm to respond to high temperature and humidity. These results provide insights into the genes and biological processes involved in high temperature and humidity tolerance in the silkworm, and advance our understanding of thermal tolerance in insects. PMID:28542312

Comparative transcriptome profiling of a thermal resistant vs. sensitive silkworm strain in response to high temperature under stressful humidity condition.

PubMed

Xiao, Wenfu; Chen, Peng; Xiao, Jinshu; Wang, La; Liu, Taihang; Wu, Yunfei; Dong, Feifan; Jiang, Yaming; Pan, Minhui; Zhang, Youhong; Lu, Cheng

2017-01-01

Thermotolerance is important particularly for poikilotherms such as insects. Understanding the mechanisms by which insects respond to high temperatures can provide insights into their adaptation to the environment. Therefore, in this study, we performed a transcriptome analysis of two silkworm strains with significantly different resistance to heat as well as humidity; the thermo-resistant strain 7532 and the thermos-sensitive strain Knobbed. We identified in total 4,944 differentially expressed genes (DEGs) using RNA-Seq. Among these, 4,390 were annotated and 554 were novel. Gene Ontology (GO) analysis of 747 DEGs identified between RT_48h (Resistant strain with high-temperature Treatment for 48 hours) and ST_48h (Sensitive strain with high-temperature Treatment for 48 hours) showed significant enrichment of 12 GO terms including metabolic process, extracellular region and serine-type peptidase activity. Moreover, we discovered 12 DEGs that may contribute to the heat-humidity stress response in the silkworm. Our data clearly showed that 48h post-exposure may be a critical time point for silkworm to respond to high temperature and humidity. These results provide insights into the genes and biological processes involved in high temperature and humidity tolerance in the silkworm, and advance our understanding of thermal tolerance in insects.

Transcriptomic basis for drought-resistance in Brassica napus L.

NASA Astrophysics Data System (ADS)

Wang, Pei; Yang, Cuiling; Chen, Hao; Song, Chunpeng; Zhang, Xiao; Wang, Daojie

2017-01-01

Based on transcriptomic data from four experimental settings with drought-resistant and drought-sensitive cultivars under drought and well-watered conditions, statistical analysis revealed three categories encompassing 169 highly differentially expressed genes (DEGs) in response to drought in Brassica napus L., including 37 drought-resistant cultivar-related genes, 35 drought-sensitive cultivar-related genes and 97 cultivar non-specific ones. We provide evidence that the identified DEGs were fairly uniformly distributed on different chromosomes and their expression patterns are variety specific. Except commonly enriched in response to various stimuli or stresses, different categories of DEGs show specific enrichment in certain biological processes or pathways, which indicated the possibility of functional differences among the three categories. Network analysis revealed relationships among the 169 DEGs, annotated biological processes and pathways. The 169 DEGs can be classified into different functional categories via preferred pathways or biological processes. Some pathways might simultaneously involve a large number of shared DEGs, and these pathways are likely to cross-talk and have overlapping biological functions. Several members of the identified DEGs fit to drought stress signal transduction pathway in Arabidopsis thaliana. Finally, quantitative real-time PCR validations confirmed the reproducibility of the RNA-seq data. These investigations are profitable for the improvement of crop varieties through transgenic engineering.

Low Temperature and Short-Term High-CO2 Treatment in Postharvest Storage of Table Grapes at Two Maturity Stages: Effects on Transcriptome Profiling

PubMed Central

Rosales, Raquel; Romero, Irene; Fernandez-Caballero, Carlos; Escribano, M. Isabel; Merodio, Carmen; Sanchez-Ballesta, M. Teresa

2016-01-01

Table grapes (Vitis vinifera cv. Cardinal) are highly perishable and their quality deteriorates during postharvest storage at low temperature mainly because of sensitivity to fungal decay and senescence of rachis. The application of a 3-day CO2 treatment (20 kPa CO2 + 20 kPa O2 + 60 kPa N2) at 0°C reduced total decay and retained fruit quality in early and late-harvested table grapes during postharvest storage. In order to study the transcriptional responsiveness of table grapes to low temperature and high CO2 levels in the first stage of storage and how the maturity stage affect these changes, we have performed a comparative large-scale transcriptional analysis using the custom-made GrapeGen GeneChip®. In the first stage of storage, low temperature led to a significantly intense change in grape skin transcriptome irrespective of fruit maturity, although there were different changes within each stage. In the case of CO2 treated samples, in comparison to fruit at time zero, only slight differences were observed. Functional enrichment analysis revealed that major modifications in the transcriptome profile of early- and late-harvested grapes stored at 0°C are linked to biotic and abiotic stress-responsive terms. However, in both cases there is a specific reprogramming of the transcriptome during the first stage of storage at 0°C in order to withstand the cold stress. Thus, genes involved in gluconeogenesis, photosynthesis, mRNA translation and lipid transport were up-regulated in the case of early-harvested grapes, and genes related to protein folding stability and intracellular membrane trafficking in late-harvested grapes. The beneficial effect of high CO2 treatment maintaining table grape quality seems to be an active process requiring the induction of several transcription factors and kinases in early-harvested grapes, and the activation of processes associated to the maintenance of energy in late-harvested grapes. PMID:27468290

Cloning and characterization of the ONAC106 gene from Oryza sativa cultivar Kuku Belang

NASA Astrophysics Data System (ADS)

Basri, Khairunnisa; Sukiran, Noor Liyana; Zainal, Zamri

2016-11-01

Plants possess different mechanisms in stress response, where induction of stress-responsive genes provides tolerance to unfavorable conditions. Stress-responsive genes are characterized for functional and regulatory genes that help in overcoming stress by molecular, biochemical and morphological adaptations. NAC transcription factors are one of the regulatory proteins that involved in stress signaling pathway. A putative NAC transcription factor, ONAC016 was identified from drought transcriptomic data. Our data suggested that ONAC106 was induced by drought, but its function in abiotic stress is still unclear. In silico analysis of ONAC106 showed that this gene encodes 334 amino acids, and its protein consists of NAM (No Apical Meristem) domain. The orthologue of ONAC106 was present in several Poaceae family members, suggesting that ONAC106 is unique to monocot plants only. We found that ONAC106 was induced by salt and cold stresses, indicating that this gene involves in abiotic stress response. In addition, we also found that ONAC106 might function in defense response to pathogen invasion. The ABRE (Abscisic Acid Regulatory Element) cis-element was identified in the promoter region of ONAC106, suggesting that it may involve in the abscisic acid (ABA)-dependent signaling pathway. Based on this preliminary result, we hypothesize that ONAC106 may play a role in abiotic stress response by regulating ABA-responsive genes.

Genomic identification of WRKY transcription factors in carrot (Daucus carota) and analysis of evolution and homologous groups for plants

PubMed Central

Li, Meng-Yao; Xu, Zhi-Sheng; Tian, Chang; Huang, Ying; Wang, Feng; Xiong, Ai-Sheng

2016-01-01

WRKY transcription factors belong to one of the largest transcription factor families. These factors possess functions in plant growth and development, signal transduction, and stress response. Here, we identified 95 DcWRKY genes in carrot based on the carrot genomic and transcriptomic data, and divided them into three groups. Phylogenetic analysis of WRKY proteins from carrot and Arabidopsis divided these proteins into seven subgroups. To elucidate the evolution and distribution of WRKY transcription factors in different species, we constructed a schematic of the phylogenetic tree and compared the WRKY family factors among 22 species, which including plants, slime mold and protozoan. An in-depth study was performed to clarify the homologous factor groups of nine divergent taxa in lower and higher plants. Based on the orthologous factors between carrot and Arabidopsis, 38 DcWRKY proteins were calculated to interact with other proteins in the carrot genome. Yeast two-hybrid assay showed that DcWRKY20 can interact with DcMAPK1 and DcMAPK4. The expression patterns of the selected DcWRKY genes based on transcriptome data and qRT-PCR suggested that those selected DcWRKY genes are involved in root development, biotic and abiotic stress response. This comprehensive analysis provides a basis for investigating the evolution and function of WRKY genes. PMID:26975939

Genomic identification of WRKY transcription factors in carrot (Daucus carota) and analysis of evolution and homologous groups for plants.

PubMed

Li, Meng-Yao; Xu, Zhi-Sheng; Tian, Chang; Huang, Ying; Wang, Feng; Xiong, Ai-Sheng

2016-03-15

WRKY transcription factors belong to one of the largest transcription factor families. These factors possess functions in plant growth and development, signal transduction, and stress response. Here, we identified 95 DcWRKY genes in carrot based on the carrot genomic and transcriptomic data, and divided them into three groups. Phylogenetic analysis of WRKY proteins from carrot and Arabidopsis divided these proteins into seven subgroups. To elucidate the evolution and distribution of WRKY transcription factors in different species, we constructed a schematic of the phylogenetic tree and compared the WRKY family factors among 22 species, which including plants, slime mold and protozoan. An in-depth study was performed to clarify the homologous factor groups of nine divergent taxa in lower and higher plants. Based on the orthologous factors between carrot and Arabidopsis, 38 DcWRKY proteins were calculated to interact with other proteins in the carrot genome. Yeast two-hybrid assay showed that DcWRKY20 can interact with DcMAPK1 and DcMAPK4. The expression patterns of the selected DcWRKY genes based on transcriptome data and qRT-PCR suggested that those selected DcWRKY genes are involved in root development, biotic and abiotic stress response. This comprehensive analysis provides a basis for investigating the evolution and function of WRKY genes.

Transcriptomic changes in Cucurbita pepo fruit after cold storage: differential response between two cultivars contrasting in chilling sensitivity.

PubMed

Carvajal, F; Rosales, R; Palma, F; Manzano, S; Cañizares, J; Jamilena, M; Garrido, D

2018-02-07

Zucchini fruit is susceptible to chilling injury (CI), but the response to low storage temperature is cultivar dependent. Previous reports about the response of zucchini fruit to chilling storage have been focused on the physiology and biochemistry of this process, with little information about the molecular mechanisms underlying it. In this work, we present a comprehensive analysis of transcriptomic changes that take place after cold storage in zucchini fruit of two commercial cultivars with contrasting response to chilling stress. RNA-Seq analysis was conducted in exocarp of fruit at harvest and after 14 days of storage at 4 and 20 °C. Differential expressed genes (DEGs) were obtained comparing fruit stored at 4 °C with their control at 20 °C, and then specific and common up and down-regulated DEGs of each cultivar were identified. Functional analysis of these DEGs identified similarities between the response of zucchini fruit to low temperature and other stresses, with an important number of GO terms related to biotic and abiotic stresses overrepresented in both cultivars. This study also revealed several molecular mechanisms that could be related to chilling tolerance, since they were up-regulated in cv. Natura (CI tolerant) or down-regulated in cv. Sinatra (CI sensitive). These mechanisms were mainly those related to carbohydrate and energy metabolism, transcription, signal transduction, and protein transport and degradation. Among DEGs belonging to these pathways, we selected candidate genes that could regulate or promote chilling tolerance in zucchini fruit including the transcription factors MYB76-like, ZAT10-like, DELLA protein GAIP, and AP2/ERF domain-containing protein. This study provides a broader understanding of the important mechanisms and processes related to coping with low temperature stress in zucchini fruit and allowed the identification of some candidate genes that may be involved in the acquisition of chilling tolerance in this crop. These genes will be the basis of future studies aimed to identify markers involved in cold tolerance and aid in zucchini breeding programs.

System analysis of metabolism and the transcriptome in Arabidopsis thaliana roots reveals differential co-regulation upon iron, sulfur and potassium deficiency.

PubMed

Forieri, Ilaria; Sticht, Carsten; Reichelt, Michael; Gretz, Norbert; Hawkesford, Malcolm J; Malagoli, Mario; Wirtz, Markus; Hell, Ruediger

2017-01-01

Deprivation of mineral nutrients causes significant retardation of plant growth. This retardation is associated with nutrient-specific and general stress-induced transcriptional responses. In this study, we adjusted the external supply of iron, potassium and sulfur to cause the same retardation of shoot growth. Nevertheless, limitation by individual nutrients resulted in specific morphological adaptations and distinct shifts within the root metabolite fingerprint. The metabolic shifts affected key metabolites of primary metabolism and the stress-related phytohormones, jasmonic, salicylic and abscisic acid. These phytohormone signatures contributed to specific nutrient deficiency-induced transcriptional regulation. Limitation by the micronutrient iron caused the strongest regulation and affected 18% of the root transcriptome. Only 130 genes were regulated by all nutrients. Specific co-regulation between the iron and sulfur metabolic routes upon iron or sulfur deficiency was observed. Interestingly, iron deficiency caused regulation of a different set of genes of the sulfur assimilation pathway compared with sulfur deficiency itself, which demonstrates the presence of specific signal-transduction systems for the cross-regulation of the pathways. Combined iron and sulfur starvation experiments demonstrated that a requirement for a specific nutrient can overrule this cross-regulation. The comparative metabolomics and transcriptomics approach used dissected general stress from nutrient-specific regulation in roots of Arabidopsis. © 2016 John Wiley & Sons Ltd.

The enhanced value of combining conventional and 'omics' analyses in early assessment of drug-induced hepatobiliary injury

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ellinger-Ziegelbauer, Heidrun, E-mail: heidrun.ellinger-ziegelbauer@bayerhealthcare.com; Adler, Melanie; Amberg, Alexander

2011-04-15

The InnoMed PredTox consortium was formed to evaluate whether conventional preclinical safety assessment can be significantly enhanced by incorporation of molecular profiling ('omics') technologies. In short-term toxicological studies in rats, transcriptomics, proteomics and metabolomics data were collected and analyzed in relation to routine clinical chemistry and histopathology. Four of the sixteen hepato- and/or nephrotoxicants given to rats for 1, 3, or 14 days at two dose levels induced similar histopathological effects. These were characterized by bile duct necrosis and hyperplasia and/or increased bilirubin and cholestasis, in addition to hepatocyte necrosis and regeneration, hepatocyte hypertrophy, and hepatic inflammation. Combined analysis ofmore » liver transcriptomics data from these studies revealed common gene expression changes which allowed the development of a potential sequence of events on a mechanistic level in accordance with classical endpoint observations. This included genes implicated in early stress responses, regenerative processes, inflammation with inflammatory cell immigration, fibrotic processes, and cholestasis encompassing deregulation of certain membrane transporters. Furthermore, a preliminary classification analysis using transcriptomics data suggested that prediction of cholestasis may be possible based on gene expression changes seen at earlier time-points. Targeted bile acid analysis, based on LC-MS metabonomics data demonstrating increased levels of conjugated or unconjugated bile acids in response to individual compounds, did not provide earlier detection of toxicity as compared to conventional parameters, but may allow distinction of different types of hepatobiliary toxicity. Overall, liver transcriptomics data delivered mechanistic and molecular details in addition to the classical endpoint observations which were further enhanced by targeted bile acid analysis using LC/MS metabonomics.« less

Wild soybean roots depend on specific transcription factors and oxidation reduction related genesin response to alkaline stress.

PubMed

DuanMu, Huizi; Wang, Yang; Bai, Xi; Cheng, Shufei; Deyholos, Michael K; Wong, Gane Ka-Shu; Li, Dan; Zhu, Dan; Li, Ran; Yu, Yang; Cao, Lei; Chen, Chao; Zhu, Yanming

2015-11-01

Soil alkalinity is an important environmental problem limiting agricultural productivity. Wild soybean (Glycine soja) shows strong alkaline stress tolerance, so it is an ideal plant candidate for studying the molecular mechanisms of alkaline tolerance and identifying alkaline stress-responsive genes. However, limited information is available about G. soja responses to alkaline stress on a genomic scale. Therefore, in the present study, we used RNA sequencing to compare transcript profiles of G. soja root responses to sodium bicarbonate (NaHCO3) at six time points, and a total of 68,138,478 pairs of clean reads were obtained using the Illumina GAIIX. Expression patterns of 46,404 G. soja genes were profiled in all six samples based on RNA-seq data using Cufflinks software. Then, t12 transcription factors from MYB, WRKY, NAC, bZIP, C2H2, HB, and TIFY families and 12 oxidation reduction related genes were chosen and verified to be induced in response to alkaline stress by using quantitative real-time polymerase chain reaction (qRT-PCR). The GO functional annotation analysis showed that besides "transcriptional regulation" and "oxidation reduction," these genes were involved in a variety of processes, such as "binding" and "response to stress." This is the first comprehensive transcriptome profiling analysis of wild soybean root under alkaline stress by RNA sequencing. Our results highlight changes in the gene expression patterns and identify a set of genes induced by NaHCO3 stress. These findings provide a base for the global analyses of G. soja alkaline stress tolerance mechanisms.

Overexpression of the brassinosteroid biosynthetic gene DWF4 in Brassica napus simultaneously increases seed yield and stress tolerance

PubMed Central

Sahni, Sangita; Prasad, Bishun D.; Liu, Qing; Grbic, Vojislava; Sharpe, Andrew; Singh, Surinder P.; Krishna, Priti

2016-01-01

As a resource allocation strategy, plant growth and defense responses are generally mutually antagonistic. Brassinosteroid (BR) regulates many aspects of plant development and stress responses, however, genetic evidence of its integrated effects on plant growth and stress tolerance is lacking. We overexpressed the Arabidopsis BR biosynthetic gene AtDWF4 in the oilseed plant Brassica napus and scored growth and stress response phenotypes. The transgenic B. napus plants, in comparison to wild type, displayed increased seed yield leading to increased overall oil content per plant, higher root biomass and root length, significantly better tolerance to dehydration and heat stress, and enhanced resistance to necrotrophic fungal pathogens Leptosphaeria maculans and Sclerotinia sclerotiorum. Transcriptome analysis supported the integrated effects of BR on growth and stress responses; in addition to BR responses associated with growth, a predominant plant defense signature, likely mediated by BES1/BZR1, was evident in the transgenic plants. These results establish that BR can interactively and simultaneously enhance abiotic and biotic stress tolerance and plant productivity. The ability to confer pleiotropic beneficial effects that are associated with different agronomic traits suggests that BR–related genes may be important targets for simultaneously increasing plant productivity and performance under stress conditions. PMID:27324083

Transcriptome analysis of the sulfate deficiency response in the marine microalga Emiliania huxleyi.

PubMed

Bochenek, Michal; Etherington, Graham J; Koprivova, Anna; Mugford, Sam T; Bell, Thomas G; Malin, Gill; Kopriva, Stanislav

2013-08-01

The response to sulfate deficiency of plants and freshwater green algae has been extensively analysed by system biology approaches. By contrast, seawater sulfate concentration is high and very little is known about the sulfur metabolism of marine organisms. Here, we used a combination of metabolite analysis and transcriptomics to analyse the response of the marine microalga Emiliania huxleyi as it acclimated to sulfate limitation. Lowering sulfate availability in artificial seawater from 25 to 5 mM resulted in significant reduction in growth and intracellular concentrations of dimethylsulfoniopropionate and glutathione. Sulfate-limited E. huxleyi cells showed increased sulfate uptake but sulfate reduction to sulfite did not seem to be regulated. Sulfate limitation in E. huxleyi affected expression of 1718 genes. The vast majority of these genes were upregulated, including genes involved in carbohydrate and lipid metabolism, and genes involved in the general stress response. The acclimation response of E. huxleyi to sulfate deficiency shows several similarities to the well-described responses of Arabidopsis and Chlamydomonas, but also has many unique features. This dataset shows that even though E. huxleyi is adapted to constitutively high sulfate concentration, it retains the ability to re-program its gene expression in response to reduced sulfate availability. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

METAL BIOSENSORS: DEVELOPMENT AND ENVIRONMENTAL TESTING

EPA Science Inventory

Proteomic and Transcriptional Findings

P. putida cells responded differentially to Cd and Cu exposures at the proteomic and transcriptome levels. The cells displayed different stress responses that correlated with a more intense oxidative stress imposed...

No Time to Waste: Transcriptome Study Reveals that Drought Tolerance in Barley May Be Attributed to Stressed-Like Expression Patterns that Exist before the Occurrence of Stress

PubMed Central

Janiak, Agnieszka; Kwasniewski, Miroslaw; Sowa, Marta; Gajek, Katarzyna; Żmuda, Katarzyna; Kościelniak, Janusz; Szarejko, Iwona

2018-01-01

Plant survival in adverse environmental conditions requires a substantial change in the metabolism, which is reflected by the extensive transcriptome rebuilding upon the occurrence of the stress. Therefore, transcriptomic studies offer an insight into the mechanisms of plant stress responses. Here, we present the results of global gene expression profiling of roots and leaves of two barley genotypes with contrasting ability to cope with drought stress. Our analysis suggests that drought tolerance results from a certain level of transcription of stress-influenced genes that is present even before the onset of drought. Genes that predispose the plant to better drought survival play a role in the regulatory network of gene expression, including several transcription factors, translation regulators and structural components of ribosomes. An important group of genes is involved in signaling mechanisms, with significant contribution of hormone signaling pathways and an interplay between ABA, auxin, ethylene and brassinosteroid homeostasis. Signal transduction in a drought tolerant genotype may be more efficient through the expression of genes required for environmental sensing that are active already during normal water availability and are related to actin filaments and LIM domain proteins, which may function as osmotic biosensors. Better survival of drought may also be attributed to more effective processes of energy generation and more efficient chloroplasts biogenesis. Interestingly, our data suggest that several genes involved in a photosynthesis process are required for the establishment of effective drought response not only in leaves, but also in roots of barley. Thus, we propose a hypothesis that root plastids may turn into the anti-oxidative centers protecting root macromolecules from oxidative damage during drought stress. Specific genes and their potential role in building up a drought-tolerant barley phenotype is extensively discussed with special emphasis on processes that take place in barley roots. When possible, the interconnections between particular factors are emphasized to draw a broader picture of the molecular mechanisms of drought tolerance in barley. PMID:29375595

No Time to Waste: Transcriptome Study Reveals that Drought Tolerance in Barley May Be Attributed to Stressed-Like Expression Patterns that Exist before the Occurrence of Stress.

PubMed

Janiak, Agnieszka; Kwasniewski, Miroslaw; Sowa, Marta; Gajek, Katarzyna; Żmuda, Katarzyna; Kościelniak, Janusz; Szarejko, Iwona

2017-01-01

Plant survival in adverse environmental conditions requires a substantial change in the metabolism, which is reflected by the extensive transcriptome rebuilding upon the occurrence of the stress. Therefore, transcriptomic studies offer an insight into the mechanisms of plant stress responses. Here, we present the results of global gene expression profiling of roots and leaves of two barley genotypes with contrasting ability to cope with drought stress. Our analysis suggests that drought tolerance results from a certain level of transcription of stress-influenced genes that is present even before the onset of drought. Genes that predispose the plant to better drought survival play a role in the regulatory network of gene expression, including several transcription factors, translation regulators and structural components of ribosomes. An important group of genes is involved in signaling mechanisms, with significant contribution of hormone signaling pathways and an interplay between ABA, auxin, ethylene and brassinosteroid homeostasis. Signal transduction in a drought tolerant genotype may be more efficient through the expression of genes required for environmental sensing that are active already during normal water availability and are related to actin filaments and LIM domain proteins, which may function as osmotic biosensors. Better survival of drought may also be attributed to more effective processes of energy generation and more efficient chloroplasts biogenesis. Interestingly, our data suggest that several genes involved in a photosynthesis process are required for the establishment of effective drought response not only in leaves, but also in roots of barley. Thus, we propose a hypothesis that root plastids may turn into the anti-oxidative centers protecting root macromolecules from oxidative damage during drought stress. Specific genes and their potential role in building up a drought-tolerant barley phenotype is extensively discussed with special emphasis on processes that take place in barley roots. When possible, the interconnections between particular factors are emphasized to draw a broader picture of the molecular mechanisms of drought tolerance in barley.

Active transcriptomic and proteomic reprogramming in the C. elegans nucleotide excision repair mutant xpa-1.

PubMed

Arczewska, Katarzyna D; Tomazella, Gisele G; Lindvall, Jessica M; Kassahun, Henok; Maglioni, Silvia; Torgovnick, Alessandro; Henriksson, Johan; Matilainen, Olli; Marquis, Bryce J; Nelson, Bryant C; Jaruga, Pawel; Babaie, Eshrat; Holmberg, Carina I; Bürglin, Thomas R; Ventura, Natascia; Thiede, Bernd; Nilsen, Hilde

2013-05-01

Transcription-blocking oxidative DNA damage is believed to contribute to aging and to underlie activation of oxidative stress responses and down-regulation of insulin-like signaling (ILS) in Nucleotide Excision Repair (NER) deficient mice. Here, we present the first quantitative proteomic description of the Caenorhabditis elegans NER-defective xpa-1 mutant and compare the proteome and transcriptome signatures. Both methods indicated activation of oxidative stress responses, which was substantiated biochemically by a bioenergetic shift involving increased steady-state reactive oxygen species (ROS) and Adenosine triphosphate (ATP) levels. We identify the lesion-detection enzymes of Base Excision Repair (NTH-1) and global genome NER (XPC-1 and DDB-1) as upstream requirements for transcriptomic reprogramming as RNA-interference mediated depletion of these enzymes prevented up-regulation of genes over-expressed in the xpa-1 mutant. The transcription factors SKN-1 and SLR-2, but not DAF-16, were identified as effectors of reprogramming. As shown in human XPA cells, the levels of transcription-blocking 8,5'-cyclo-2'-deoxyadenosine lesions were reduced in the xpa-1 mutant compared to the wild type. Hence, accumulation of cyclopurines is unlikely to be sufficient for reprogramming. Instead, our data support a model where the lesion-detection enzymes NTH-1, XPC-1 and DDB-1 play active roles to generate a genomic stress signal sufficiently strong to result in transcriptomic reprogramming in the xpa-1 mutant.

Transcriptome comparison in the pituitary-adrenal axis between Beagle and Chinese Field dogs after chronic stress exposure.

PubMed

Luo, Wei; Fang, Meixia; Xu, Haiping; Xing, Huijie; Nie, Qinghua

2015-10-01

Chronic stress can induce a series of maladjustments, and the response to stress is partly regulated by the hypothalamus-pituitary-adrenal axis. The aim of this study was to investigate the genetic mechanisms of this axis regulating stress responsiveness. The pituitary and adrenal cortex of Beagle and Chinese Field Dog (CFD) from a stress exposure group [including Beagle pituitary 1 (BP1), CFD pituitary 1 (CFDP1), Beagle adrenal cortex 1 (BAC1), CFD adrenal cortex 1 (CFDAC1)] and a control group [including Beagle pituitary 2 (BP2), CFD pituitary 2 (CFDP2), Beagle adrenal cortex 2 (BAC2), CFD adrenal cortex 2 (CFDAC2)], selected to perform RNA-seq transcriptome comparisons, showed that 40, 346, 376, 69, 70, 38, 57 and 71 differentially expressed genes were detected in BP1 vs. BP2, CFDP1 vs. CFDP2, BP1 vs. CFDP1, BP2 vs. CFDP2, BAC1 vs. BAC2, CFDAC1 vs. CFDAC2, BAC1 vs. CFDAC1 and BAC2 vs. CFDAC2 respectively. NPB was a gene common to BAC1 vs. BAC2 and CFDAC1 vs. CFDAC2, indicating it was a potential gene affecting response to chronic stress, regardless of the extent of chronic stress induced. PLP1 was a gene common to BP1 vs. CFDP1 and BP2 vs. CFDP2, suggesting its important roles in affecting the stress-tolerance difference between the two breeds, regardless of whether there was stress exposure or not. Pathway analysis found 12, 4, 11 and 1 enriched pathway in the comparisons of BP1 vs. CFDP1, BP2 vs. CFDP2, CFDP1 vs. CFDP2 and BAC1 vs. BAC2 respectively. Glutamatergic synapse, neuroactive ligand-receptor interaction, retrograde endocannabinoid signaling, GABAergic synapse, calcium signaling pathway and dopaminergic synapse were the most significantly enriched pathways in both CFDP1 vs. CFDP2 and BP1 vs. CFDP1. GO, KEGG pathway and gene network analysis demonstrated that GRIA3, GRIN2A, GRIN2B and NPY were important in regulating the stress response in CFD. Nevertheless, ADORA1, CAMK2A, GRM1, GRM7 and NR4A1 might be critical genes contributing to the stress-tolerance difference between CFD and Beagle when subjected to stress exposure. In addition, RGS4 and SYN1 might play important roles both in regulating the stress response in CFD and in affecting the stress-tolerance difference in different breeds. These observations clearly showed that some genes in the adrenal cortex and pituitary could regulate the stress response in Beagle and CFDs, whereas some others could affect the stress-tolerance difference between these two breeds. Our results can contribute to a more comprehensive understanding of the genetic mechanisms of response to chronic stress. © 2015 Stichting International Foundation for Animal Genetics.

Cell Wall Metabolism in Response to Abiotic Stress

PubMed Central

Gall, Hyacinthe Le; Philippe, Florian; Domon, Jean-Marc; Gillet, Françoise; Pelloux, Jérôme; Rayon, Catherine

2015-01-01

This review focuses on the responses of the plant cell wall to several abiotic stresses including drought, flooding, heat, cold, salt, heavy metals, light, and air pollutants. The effects of stress on cell wall metabolism are discussed at the physiological (morphogenic), transcriptomic, proteomic and biochemical levels. The analysis of a large set of data shows that the plant response is highly complex. The overall effects of most abiotic stress are often dependent on the plant species, the genotype, the age of the plant, the timing of the stress application, and the intensity of this stress. This shows the difficulty of identifying a common pattern of stress response in cell wall architecture that could enable adaptation and/or resistance to abiotic stress. However, in most cases, two main mechanisms can be highlighted: (i) an increased level in xyloglucan endotransglucosylase/hydrolase (XTH) and expansin proteins, associated with an increase in the degree of rhamnogalacturonan I branching that maintains cell wall plasticity and (ii) an increased cell wall thickening by reinforcement of the secondary wall with hemicellulose and lignin deposition. Taken together, these results show the need to undertake large-scale analyses, using multidisciplinary approaches, to unravel the consequences of stress on the cell wall. This will help identify the key components that could be targeted to improve biomass production under stress conditions. PMID:27135320

Comparative Transcriptome Analysis of the Cosmopolitan Marine Fungus Corollospora maritima Under Two Physiological Conditions

PubMed Central

Velez, Patricia; Alejandri-Ramírez, Naholi D.; González, María C.; Estrada, Karel J.; Sanchez-Flores, Alejandro; Dinkova, Tzvetanka D.

2015-01-01

Marine sandy beaches represent dynamic environments often subject to harsh conditions and climate fluctuations, where natural and anthropogenic inputs of freshwater from fluvial and pluvial sources alter salinity, which has been recognized as a key variable affecting the distribution of aquatic organisms and influencing critical physiological processes. The marine arenicolous fungus Corollospora maritima is a worldwide-distributed saprobe that has been reported to present tolerance to freshwater. Here, we present a transcriptome analysis that will provide the first insight of the genomic content for this fungus and a gene expression comparison between two different salinity conditions. We also identified genes that are candidates for being differentially expressed in response to environmental variations on salinity during the fungal growth. The de novo reconstruction of C. maritima transcriptome Illumina sequencing provided a total of 14,530 transcripts (16 megabases). The comparison between the two growth conditions rendered 103 genes specifically overexpressed in seawater, and 132 genes specifically up-regulated under freshwater. Using fungal isolates collected from different beaches, the specific environmental regulation of particular transcript differential expression was confirmed by RT-qPCR. To our knowledge, this is the first analysis that explores the marine fungus C. maritima molecular responses to overcome freshwater stress, and these data could shed light to understand the fungal adaptation and plasticity mechanisms to the marine habitat. PMID:26116293

Genome-Wide Small RNA Analysis of Soybean Reveals Auxin-Responsive microRNAs that are Differentially Expressed in Response to Salt Stress in Root Apex

PubMed Central

Sun, Zhengxi; Wang, Youning; Mou, Fupeng; Tian, Yinping; Chen, Liang; Zhang, Senlei; Jiang, Qiong; Li, Xia

2016-01-01

Root growth and the architecture of the root system in Arabidopsis are largely determined by root meristematic activity. Legume roots show strong developmental plasticity in response to both abiotic and biotic stimuli, including symbiotic rhizobia. However, a global analysis of gene regulation in the root meristem of soybean plants is lacking. In this study, we performed a global analysis of the small RNA transcriptome of root tips from soybean seedlings grown under normal and salt stress conditions. In total, 71 miRNA candidates, including known and novel variants of 59 miRNA families, were identified. We found 66 salt-responsive miRNAs in the soybean root meristem; among them, 22 are novel miRNAs. Interestingly, we found auxin-responsive cis-elements in the promoters of many salt-responsive miRNAs, implying that these miRNAs may be regulated by auxin and auxin signaling plays a key role in regulating the plasticity of the miRNAome and root development in soybean. A functional analysis of miR399, a salt-responsive miRNA in the root meristem, indicates the crucial role of this miRNA in modulating soybean root developmental plasticity. Our data provide novel insight into the miRNAome-mediated regulatory mechanism in soybean root growth under salt stress. PMID:26834773

Inhibiting ethylene perception with 1-methylcyclopropene triggers molecular responses aimed to cope with cell toxicity and increased respiration in citrus fruits.

PubMed

Establés-Ortiz, Beatriz; Romero, Paco; Ballester, Ana-Rosa; González-Candelas, Luis; Lafuente, María T

2016-06-01

The ethylene perception inhibitor 1-methylcyclopropene (1-MCP) has been critical in understanding the hormone's mode of action. However, 1-MCP may trigger other processes that could vary the interpretation of results related until now to ethylene, which we aim to understand by using transcriptomic analysis. Transcriptomic changes in ethylene and 1-MCP-treated 'Navelate' (Citrus sinensis L. Osbeck) oranges were studied in parallel with changes in ethylene production, respiration and peel damage. The effects of compounds modifying the levels of the ethylene co-product cyanide and nitric oxide (NO) on fruit physiology were also studied. Results suggested that: 1) The ethylene treatment caused sub-lethal stress since it induced stress-related responses and reduced peel damage; 2) 1-MCP induced ethylene-dependent and ethylene-independent responsive networks; 3) 1-MCP triggered ethylene overproduction, stress-related responses and metabolic shifts aimed to cope with cell toxicity, which mostly affected to the inner part of the peel (albedo); 4) 1-MCP increased respiration and drove metabolism reconfiguration for favoring energy conservation but up-regulated genes related to lipid and protein degradation and triggered the over-expression of genes associated with the plasma membrane cellular component; 5) Xenobiotics and/or reactive oxygen species (ROS) might act as signals for defense responses in the ethylene-treated fruit, while their uncontrolled generation would induce processes mimicking cell death and damage in 1-MCP-treated fruit; 6) ROS, the ethylene co-product cyanide and NO may converge in the toxic effects of 1-MCP. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Physiological and transcriptome response to cadmium in cosmos (Cosmos bipinnatus Cav.) seedlings.

PubMed

Liu, Yujing; Yu, Xiaofang; Feng, Yimei; Zhang, Chao; Wang, Chao; Zeng, Jian; Huang, Zhuo; Kang, Houyang; Fan, Xing; Sha, Lina; Zhang, Haiqin; Zhou, Yonghong; Gao, Suping; Chen, Qibing

2017-10-31

To date, several species of Asteraceae have been considered as Cd-accumulators. However, little information on the Cd tolerance and associated mechanisms of Asteraceae species Cosmos bipinnatus, is known. Presently, several physiological indexes and transcriptome profiling under Cd stress were investigated. C. bipinnatus exhibited strong Cd tolerance and recommended as a Cd-accumulator, although the biomasses were reduced by Cd. Meanwhile, Cd stresses reduced Zn and Ca uptake, but increased Fe uptake. Subcellular distribution indicated that the vacuole sequestration in root mainly detoxified Cd under lower Cd stress. Whilst, cell wall binding and vacuole sequestration in root co-detoxified Cd under high Cd exposure. Meanwhile, 66,407 unigenes were assembled and 41,674 (62.75%) unigenes were annotated in at least one database. 2,658 DEGs including 1,292 up-regulated unigenes and 1,366 down-regulated unigenes were identified under 40 μmol/L Cd stress. Among of these DEGs, ZIPs, HMAs, NRAMPs and ABC transporters might participate in Cd uptake, translocation and accumulation. Many DEGs participating in several processes such as cell wall biosynthesis, GSH metabolism, TCA cycle and antioxidant system probably play critical roles in cell wall binding, vacuole sequestration and detoxification. These results provided a novel insight into the physiological and transcriptome response to Cd in C. bipinnatus seedlings.

Toxicogenomic response of Mycobacterium bovis BCG to peracetic acid and a comparative analysis of the M. bovis BCG response to three oxidative disinfectants.

PubMed

Nde, Chantal W; Toghrol, Freshteh; Jang, Hyeung-Jin; Bentley, William E

2011-04-01

Tuberculosis is a leading cause of death worldwide and infects thousands of Americans annually. Mycobacterium bovis causes tuberculosis in humans and several animal species. Peracetic acid is an approved tuberculocide in hospital and domestic environments. This study presents for the first time the transcriptomic changes in M. bovis BCG after treatment with 0.1 mM peracetic acid for 10 and 20 min. This study also presents for the first time a comparison among the transcriptomic responses of M. bovis BCG to three oxidative disinfectants: peracetic acid, sodium hypochlorite, and hydrogen peroxide after 10 min of treatment. Results indicate that arginine biosynthesis, virulence, and oxidative stress response genes were upregulated after both peracetic acid treatment times. Three DNA repair genes were downregulated after 10 and 20 min and cell wall component genes were upregulated after 20 min. The devR-devS signal transduction system was upregulated after 10 min, suggesting a role in the protection against peracetic acid treatment. Results also suggest that peracetic acid and sodium hypochlorite both induce the expression of the ctpF gene which is upregulated in hypoxic environments. Further, this study reveals that in M. bovis BCG, hydrogen peroxide and peracetic acid both induce the expression of katG involved in oxidative stress response and the mbtD and mbtI genes involved in iron regulation/virulence.

Sequencing-based gene network analysis provides a core set of gene resource for understanding thermal adaptation in Zhikong scallop Chlamys farreri.

PubMed

Fu, X; Sun, Y; Wang, J; Xing, Q; Zou, J; Li, R; Wang, Z; Wang, S; Hu, X; Zhang, L; Bao, Z

2014-01-01

Marine organisms are commonly exposed to variable environmental conditions, and many of them are under threat from increased sea temperatures caused by global climate change. Generating transcriptomic resources under different stress conditions are crucial for understanding molecular mechanisms underlying thermal adaptation. In this study, we conducted transcriptome-wide gene expression profiling of the scallop Chlamys farreri challenged by acute and chronic heat stress. Of the 13 953 unique tags, more than 850 were significantly differentially expressed at each time point after acute heat stress, which was more than the number of tags differentially expressed (320-350) under chronic heat stress. To obtain a systemic view of gene expression alterations during thermal stress, a weighted gene coexpression network was constructed. Six modules were identified as acute heat stress-responsive modules. Among them, four modules involved in apoptosis regulation, mRNA binding, mitochondrial envelope formation and oxidation reduction were downregulated. The remaining two modules were upregulated. One was enriched with chaperone and the other with microsatellite sequences, whose coexpression may originate from a transcription factor binding site. These results indicated that C. farreri triggered several cellular processes to acclimate to elevated temperature. No modules responded to chronic heat stress, suggesting that the scallops might have acclimated to elevated temperature within 3 days. This study represents the first sequencing-based gene network analysis in a nonmodel aquatic species and provides valuable gene resources for the study of thermal adaptation, which should assist in the development of heat-tolerant scallop lines for aquaculture. © 2013 John Wiley & Sons Ltd.

Transcriptome Analysis of Blunt Snout Bream (Megalobrama amblycephala) Reveals Putative Differential Expression Genes Related to Growth and Hypoxia

PubMed Central

Li, Fu-Gui; Chen, Jie; Jiang, Xia-Yun; Zou, Shu-Ming

2015-01-01

The blunt snout bream (Megalobrama amblycephala) is an important freshwater aquaculture species, but it is sensitive to hypoxia. No transcriptome data related to growth and hypoxia response are available for this species. In this study, we performed de novo transcriptome sequencing for the liver and gills of the fast-growth family and slow-growth family derived from ‘Pujiang No.1’ F10 blunt snout bream that were under hypoxic stress and normoxia, respectively. The fish were divided into the following 4 groups: fast-growth family under hypoxic stress, FH; slow-growth family under hypoxic stress, SH; fast-growth family under normoxia, FN; and slow-growth family under normoxia, SN. A total of 185 million high-quality reads were obtained from the normalized cDNA of the pooled samples, which were assembled into 465,582 contigs and 237,172 transcripts. A total of 31,338 transcripts from the same locus (unigenes) were annotated and assigned to 104 functional groups, and 23,103 unigenes were classified into seven main categories, including 45 secondary KEGG pathways. A total of 22,255 (71%) known putative unigenes were found to be shared across the genomes of five model fish species and mammals, and a substantial number (9.4%) of potentially novel genes were identified. When 6,639 unigenes were used in the analysis of differential expression (DE) genes, the number of putative DE genes related to growth pathways in FH, SH, SN and FN was 159, 118, 92 and 65 in both the liver and gills, respectively, and the number of DE genes related to hypoxic response was 57, 33, 23 and 21 in FH, FN, SH and SN, respectively. Our results suggest that growth performance of the fast-growth family should be due to complex mutual gene regulatory mechanisms of these putative DE genes between growth and hypoxia. PMID:26554582

Organization of cis-acting regulatory elements in osmotic- and cold-stress-responsive promoters.

PubMed

Yamaguchi-Shinozaki, Kazuko; Shinozaki, Kazuo

2005-02-01

cis-Acting regulatory elements are important molecular switches involved in the transcriptional regulation of a dynamic network of gene activities controlling various biological processes, including abiotic stress responses, hormone responses and developmental processes. In particular, understanding regulatory gene networks in stress response cascades depends on successful functional analyses of cis-acting elements. The ever-improving accuracy of transcriptome expression profiling has led to the identification of various combinations of cis-acting elements in the promoter regions of stress-inducible genes involved in stress and hormone responses. Here we discuss major cis-acting elements, such as the ABA-responsive element (ABRE) and the dehydration-responsive element/C-repeat (DRE/CRT), that are a vital part of ABA-dependent and ABA-independent gene expression in osmotic and cold stress responses.

Differential proteomic analysis reveals sequential heat stress-responsive regulatory network in radish (Raphanus sativus L.) taproot.

PubMed

Wang, Ronghua; Mei, Yi; Xu, Liang; Zhu, Xianwen; Wang, Yan; Guo, Jun; Liu, Liwang

2018-05-01

Differential abundance protein species (DAPS) involved in reducing damage and enhancing thermotolerance in radish were firstly identified. Proteomic analysis and omics association analysis revealed a HS-responsive regulatory network in radish. Heat stress (HS) is a major destructive factor influencing radish production and supply in summer, for radish is a cool season vegetable crop being susceptible to high temperature. In this study, the proteome changes of radish taproots under 40 °C treatment at 0 h (Control), 12 h (Heat12) and 24 h (Heat24) were analyzed using iTRAQ (Isobaric Tag for Relative and Absolute Quantification) approach. In total, 2258 DAPS representing 1542 differentially accumulated uniprotein species which respond to HS were identified. A total of 604, 910 and 744 DAPS was detected in comparison of Control vs. Heat12, Control vs. Heat24, and Heat12 vs. Heat24, respectively. Gene ontology and pathway analysis showed that annexin, ubiquitin-conjugating enzyme, ATP synthase, heat shock protein (HSP) and other stress-related proteins were predominately enriched in signal transduction, stress and defense pathways, photosynthesis and energy metabolic pathways, working cooperatively to reduce stress-induced damage in radish. Based on iTRAQ combined with the transcriptomics analysis, a schematic model of a sequential HS-responsive regulatory network was proposed. The initial sensing of HS occurred at the plasma membrane, and then key components of stress signal transduction triggered heat-responsive genes in the plant protective metabolism to re-establish homeostasis and enhance thermotolerance. These results provide new insights into characteristics of HS-responsive DAPS and facilitate dissecting the molecular mechanisms underlying heat tolerance in radish and other root crops.

Brain Radiation Information Data Exchange (BRIDE): integration of experimental data from low-dose ionising radiation research for pathway discovery.

PubMed

Karapiperis, Christos; Kempf, Stefan J; Quintens, Roel; Azimzadeh, Omid; Vidal, Victoria Linares; Pazzaglia, Simonetta; Bazyka, Dimitry; Mastroberardino, Pier G; Scouras, Zacharias G; Tapio, Soile; Benotmane, Mohammed Abderrafi; Ouzounis, Christos A

2016-05-11

The underlying molecular processes representing stress responses to low-dose ionising radiation (LDIR) in mammals are just beginning to be understood. In particular, LDIR effects on the brain and their possible association with neurodegenerative disease are currently being explored using omics technologies. We describe a light-weight approach for the storage, analysis and distribution of relevant LDIR omics datasets. The data integration platform, called BRIDE, contains information from the literature as well as experimental information from transcriptomics and proteomics studies. It deploys a hybrid, distributed solution using both local storage and cloud technology. BRIDE can act as a knowledge broker for LDIR researchers, to facilitate molecular research on the systems biology of LDIR response in mammals. Its flexible design can capture a range of experimental information for genomics, epigenomics, transcriptomics, and proteomics. The data collection is available at: .

Differential DNA methylation and transcription profiles in date palm roots exposed to salinity

PubMed Central

Al-Harrasi, Ibtisam; Al-Yahyai, Rashid

2018-01-01

As a salt-adaptive plant, the date palm (Phoenix dactylifera L.) requires a suitable mechanism to adapt to the stress of saline soils. There is growing evidence that DNA methylation plays an important role in regulating gene expression in response to abiotic stresses, including salinity. Thus, the present study sought to examine the differential methylation status that occurs in the date palm genome when plants are exposed to salinity, and to identify salinity responsive genes that are regulated by DNA methylation. To achieve these, whole-genome bisulfite sequencing (WGBS) was employed and mRNA was sequenced from salinity-treated and untreated roots. The WGBS analysis included 324,987,795 and 317,056,091 total reads of the control and the salinity-treated samples, respectively. The analysis covered about 81% of the total genomic DNA with about 40% of mapping efficiency of the sequenced reads and an average read depth of 17-fold coverage per DNA strand, and with a bisulfite conversion rate of around 99%. The level of methylation within the differentially methylated regions (DMRs) was significantly (p < 0.05, FDR ≤ 0.05) increased in response to salinity specifically at the mCHG and mCHH sequence contexts. Consistently, the mass spectrometry and the enzyme-linked immunosorbent assay (ELISA) showed that there was a significant (p < 0.05) increase in the global DNA methylation in response to salinity. mRNA sequencing revealed the presence of 6,405 differentially regulated genes with a significant value (p < 0.001, FDR ≤ 0.05) in response to salinity. Integration of high-resolution methylome and transcriptome analyses revealed a negative correlation between mCG methylation located within the promoters and the gene expression, while a positive correlation was noticed between mCHG/mCHH methylation rations and gene expression specifically when plants grew under control conditions. Therefore, the methylome and transcriptome relationships vary based on the methylated sequence context, the methylated region within the gene, the protein-coding ability of the gene, and the salinity treatment. These results provide insights into interplay among DNA methylation and gene expression, and highlight the effect of salinity on the nature of this relationship, which may involve other genetic and epigenetic players under salt stress conditions. The results obtained from this project provide the first draft map of the differential methylome and transcriptome of date palm when exposed to an abiotic stress. PMID:29352281

Differential DNA methylation and transcription profiles in date palm roots exposed to salinity.

PubMed

Al-Harrasi, Ibtisam; Al-Yahyai, Rashid; Yaish, Mahmoud W

2018-01-01

As a salt-adaptive plant, the date palm (Phoenix dactylifera L.) requires a suitable mechanism to adapt to the stress of saline soils. There is growing evidence that DNA methylation plays an important role in regulating gene expression in response to abiotic stresses, including salinity. Thus, the present study sought to examine the differential methylation status that occurs in the date palm genome when plants are exposed to salinity, and to identify salinity responsive genes that are regulated by DNA methylation. To achieve these, whole-genome bisulfite sequencing (WGBS) was employed and mRNA was sequenced from salinity-treated and untreated roots. The WGBS analysis included 324,987,795 and 317,056,091 total reads of the control and the salinity-treated samples, respectively. The analysis covered about 81% of the total genomic DNA with about 40% of mapping efficiency of the sequenced reads and an average read depth of 17-fold coverage per DNA strand, and with a bisulfite conversion rate of around 99%. The level of methylation within the differentially methylated regions (DMRs) was significantly (p < 0.05, FDR ≤ 0.05) increased in response to salinity specifically at the mCHG and mCHH sequence contexts. Consistently, the mass spectrometry and the enzyme-linked immunosorbent assay (ELISA) showed that there was a significant (p < 0.05) increase in the global DNA methylation in response to salinity. mRNA sequencing revealed the presence of 6,405 differentially regulated genes with a significant value (p < 0.001, FDR ≤ 0.05) in response to salinity. Integration of high-resolution methylome and transcriptome analyses revealed a negative correlation between mCG methylation located within the promoters and the gene expression, while a positive correlation was noticed between mCHG/mCHH methylation rations and gene expression specifically when plants grew under control conditions. Therefore, the methylome and transcriptome relationships vary based on the methylated sequence context, the methylated region within the gene, the protein-coding ability of the gene, and the salinity treatment. These results provide insights into interplay among DNA methylation and gene expression, and highlight the effect of salinity on the nature of this relationship, which may involve other genetic and epigenetic players under salt stress conditions. The results obtained from this project provide the first draft map of the differential methylome and transcriptome of date palm when exposed to an abiotic stress.

Comparative transcriptome analysis of differentially expressed genes in foxtail millet (Setaria italica L.) during dehydration stress.

PubMed

Lata, Charu; Sahu, Pranav Pankaj; Prasad, Manoj

2010-03-19

Dehydration stress is one of the most important abiotic stresses that adversely influence crop growth and productivity. With the aim to understand the molecular mechanisms underlying dehydration stress tolerance in foxtail millet (Setaria italica L.), a drought tolerant crop, we examined its transcriptome changes at two time points (early and late) of dehydration stress. Two suppression subtractive hybridization (SSH) forward libraries were constructed from 21-day old seedlings of tolerant cv. Prasad at 0.5 and 6h PEG-induced dehydration stress. A total of 327 unique ESTs were identified from both libraries and were classified into 11 different categories according to their putative functions. The plant response against dehydration stress was complex, representing major transcripts involved in metabolism, stress, signaling, transcription regulation, translation and proteolysis. By Reverse Northern (RN) technique we identified the differential expression pattern of 327 transcripts, 86 (about 26%) of which showed > or = 1.7-fold induction. Further the obtained results were validated by quantitative real-time PCR (qRT-PCR) to have a comparative expression profiling of randomly chosen 9 up-regulated transcripts (> or =2.5 fold induction) between cv. Prasad (tolerant) and cv. Lepakshi (sensitive) upon dehydration stress. These transcripts showed a differential expression pattern in both cultivars at different time points of stress treatment as analyzed by qRT-PCR. The possible relationship of the identified transcripts with dehydration tolerance mechanism is discussed. Copyright 2010 Elsevier Inc. All rights reserved.

An emerging picture of the seed desiccome: confirmed regulators and newcomers identified using transcriptome comparison.

PubMed

Terrasson, Emmanuel; Buitink, Julia; Righetti, Karima; Ly Vu, Benoit; Pelletier, Sandra; Zinsmeister, Julia; Lalanne, David; Leprince, Olivier

2013-01-01

Desiccation tolerance (DT) is the capacity to withstand total loss of cellular water. It is acquired during seed filling and lost just after germination. However, in many species, a germinated seed can regain DT under adverse conditions such as osmotic stress. The genes, proteins and metabolites that are required to establish this DT is referred to as the desiccome. It includes both a range of protective mechanisms and underlying regulatory pathways that remain poorly understood. As a first step toward the identification of the seed desiccome of Medicago truncatula, using updated microarrays we characterized the overlapping transcriptomes associated with acquisition of DT in developing seeds and the re-establishment of DT in germinated seeds using a polyethylene glycol treatment (-1.7 MPa). The resulting list contained 740 and 2829 transcripts whose levels, respectively, increased and decreased with DT. Fourty-eight transcription factors (TF) were identified including MtABI3, MtABI5 and many genes regulating flowering transition and cell identity. A promoter enrichment analysis revealed a strong over-representation of ABRE elements together with light-responsive cis-acting elements. In Mtabi5 Tnt1 insertion mutants, DT could no longer be re-established by an osmotic stress. Transcriptome analysis on Mtabi5 radicles during osmotic stress revealed that 13 and 15% of the up-regulated and down-regulated genes, respectively, are mis-regulated in the mutants and might be putative downstream targets of MtABI5 implicated in the re-establishment of DT. Likewise, transcriptome comparisons of the desiccation sensitive Mtabi3 mutants and hairy roots ectopically expressing MtABI3 revealed that 35 and 23% of the up-regulated and down-regulated genes are acting downstream of MtABI3. Our data suggest that ABI3 and ABI5 have complementary roles in DT. Whether DT evolved by co-opting existing pathways regulating flowering and cellular phase transition and cell identity is discussed.

Genome-wide analysis of Glycine soja ubiquitin (UBQ) genes and functional analysis of GsUBQ10 in response to alkaline stress.

PubMed

Chen, Chao; Chen, Ranran; Wu, Shengyang; Zhu, Dan; Sun, Xiaoli; Liu, Beidong; Li, Qiang; Zhu, Yanming

2018-03-26

Ubiquitin is a highly conserved protein with multiple essential regulation functions through the ubiquitin-proteasome system. Even though its functions in the ubiquitin-mediated protein degradation pathway were very well characterized. The functions of ubiquitin genes in regulating alkaline stress response are not fully established. In this study, we identified 12 potential UBQ genes in Glycine soja genome, and analyzed their evolutionary relationship, conserved domains and promoter cis-elements. We also explored the expression profiles of G. soja UBQ genes under alkaline stress, based on the transcriptome sequencing. We found that the expression of GsUBQ10 was significantly induced by alkaline stress, and function of GsUBQ10 was characterized using overexpression transgenic alfalfa (Medicago sativa). Our results suggested that GsUBQ10 transgenic lines significantly improved the alkaline tolerance in alfalfa. The GsUBQ10 transgenic lines showed lower relative membrane permeability, lower malon dialdehyde content and higher catalase activity than in the wild-type plants. This indicates that GsUBQ10 is involved in regulating the reactive oxygen species accumulation under alkaline stress. Taken together, we identified an ubiquitin gene GsUBQ10 from G. soja, which plays a positive role in responses to alkaline stress in alfalfa. This article is protected by copyright. All rights reserved.

Comparative physiological, metabolomic, and transcriptomic analyses reveal mechanisms of improved abiotic stress resistance in bermudagrass [Cynodon dactylon (L). Pers.] by exogenous melatonin.

PubMed

Shi, Haitao; Jiang, Chuan; Ye, Tiantian; Tan, Dun-Xian; Reiter, Russel J; Zhang, Heng; Liu, Renyi; Chan, Zhulong

2015-02-01

Melatonin (N-acetyl-5-methoxytryptamine), a well-known animal hormone, is also involved in plant development and abiotic stress responses. In this study, it is shown that exogenous application of melatonin conferred improved salt, drought, and cold stress resistances in bermudagrass. Moreover, exogenous melatonin treatment alleviated reactive oxygen species (ROS) burst and cell damage induced by abiotic stress; this involved activation of several antioxidants. Additionally, melatonin-pre-treated plants exhibited higher concentrations of 54 metabolites, including amino acids, organic acids, sugars, and sugar alcohols, than non-treated plants under abiotic stress conditions. Genome-wide transcriptomic profiling identified 3933 transcripts (2361 up-regulated and 1572 down-regulated) that were differentially expressed in melatonin-treated plants versus controls. Pathway and gene ontology (GO) term enrichment analyses revealed that genes involved in nitrogen metabolism, major carbohydrate metabolism, tricarboxylic acid (TCA)/org transformation, transport, hormone metabolism, metal handling, redox, and secondary metabolism were over-represented after melatonin pre-treatment. Taken together, this study provides the first evidence of the protective roles of exogenous melatonin in the bermudagrass response to abiotic stresses, partially via activation of antioxidants and modulation of metabolic homeostasis. Notably, metabolic and transcriptomic analyses showed that the underlying mechanisms of melatonin could involve major reorientation of photorespiratory and carbohydrate and nitrogen metabolism. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Gene expression during different periods of the handling-stress response in Pampus argenteus

NASA Astrophysics Data System (ADS)

Sun, Peng; Tang, Baojun; Yin, Fei

2017-11-01

Common aquaculture practices subject fish to a variety of acute and chronic stressors. Such stressors are inherent in aquaculture production but can adversely affect survival, growth, immune response, reproductive capacity, and behavior. Understanding the biological mechanisms underlying stress responses helps with methods to alleviate the negative effects through better aquaculture practices, resulting in improved animal welfare and production efficiency. In the present study, transcriptome sequencing of liver and kidney was performed in silver pomfret (Pampus argenteus) subjected to handling stress versus controls. A total of 162.19 million clean reads were assembled to 30 339 unigenes. The quality of the assembly was high, with an N50 length of 2 472 bases. For function classification and pathway assignment, the unigenes were categorized into three GO (gene ontology) categories, twenty-six clusters of eggNOG (evolutionary genealogy of genes: non-supervised orthologous groups) function categories, and thirty-eight KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways. Stress affected different functional groups of genes in the tissues studied. Differentially expressed genes were mainly involved in metabolic pathways (carbohydrate metabolism, lipid metabolism, amino-acid metabolism, uptake of cofactors and vitamins, and biosynthesis of other secondary metabolites), environmental information processing (signaling molecules and their interactions), organismal systems (endocrine system, digestive system), and disease (immune, neurodegenerative, endocrine and metabolic diseases). This is the first reported analysis of genome-wide transcriptome in P. argenteus, and the findings expand our understanding of the silver pomfret genome and gene expression in association with stress. The results will be useful to future analyses of functional genes and studies of healthy artificial breeding in P. argenteus and other related fish species.

Transcriptomic study to understand thermal adaptation in a high temperature-tolerant strain of Pyropia haitanensis

PubMed Central

Wang, Wenlei; Teng, Fei; Lin, Yinghui; Ji, Dehua; Xu, Yan; Chen, Changsheng

2018-01-01

Pyropia haitanensis, a high-yield commercial seaweed in China, is currently undergoing increasing levels of high-temperature stress due to gradual global warming. The mechanisms of plant responses to high temperature stress vary with not only plant type but also the degree and duration of high temperature. To understand the mechanism underlying thermal tolerance in P. haitanensis, gene expression and regulation in response to short- and long-term temperature stresses (SHS and LHS) was investigated by performing genome-wide high-throughput transcriptomic sequencing for a high temperature tolerant strain (HTT). A total of 14,164 differential expression genes were identified to be high temperature-responsive in at least one time point by high-temperature treatment, representing 41.10% of the total number of unigenes. The present data indicated a decrease in the photosynthetic and energy metabolic rates in HTT to reduce unnecessary energy consumption, which in turn facilitated in the rapid establishment of acclimatory homeostasis in its transcriptome during SHS. On the other hand, an increase in energy consumption and antioxidant substance activity was observed with LHS, which apparently facilitates in the development of resistance against severe oxidative stress. Meanwhile, ubiquitin-mediated proteolysis, brassinosteroids, and heat shock proteins also play a vital role in HTT. The effects of SHS and LHS on the mechanism of HTT to resist heat stress were relatively different. The findings may facilitate further studies on gene discovery and the molecular mechanisms underlying high-temperature tolerance in P. haitanensis, as well as allow improvement of breeding schemes for high temperature-tolerant macroalgae that can resist global warming. PMID:29694388

Transcriptomic study to understand thermal adaptation in a high temperature-tolerant strain of Pyropia haitanensis.

PubMed

Wang, Wenlei; Teng, Fei; Lin, Yinghui; Ji, Dehua; Xu, Yan; Chen, Changsheng; Xie, Chaotian

2018-01-01

Pyropia haitanensis, a high-yield commercial seaweed in China, is currently undergoing increasing levels of high-temperature stress due to gradual global warming. The mechanisms of plant responses to high temperature stress vary with not only plant type but also the degree and duration of high temperature. To understand the mechanism underlying thermal tolerance in P. haitanensis, gene expression and regulation in response to short- and long-term temperature stresses (SHS and LHS) was investigated by performing genome-wide high-throughput transcriptomic sequencing for a high temperature tolerant strain (HTT). A total of 14,164 differential expression genes were identified to be high temperature-responsive in at least one time point by high-temperature treatment, representing 41.10% of the total number of unigenes. The present data indicated a decrease in the photosynthetic and energy metabolic rates in HTT to reduce unnecessary energy consumption, which in turn facilitated in the rapid establishment of acclimatory homeostasis in its transcriptome during SHS. On the other hand, an increase in energy consumption and antioxidant substance activity was observed with LHS, which apparently facilitates in the development of resistance against severe oxidative stress. Meanwhile, ubiquitin-mediated proteolysis, brassinosteroids, and heat shock proteins also play a vital role in HTT. The effects of SHS and LHS on the mechanism of HTT to resist heat stress were relatively different. The findings may facilitate further studies on gene discovery and the molecular mechanisms underlying high-temperature tolerance in P. haitanensis, as well as allow improvement of breeding schemes for high temperature-tolerant macroalgae that can resist global warming.

Distinct transcriptome responses to water limitation in isohydric and anisohydric grapevine cultivars.

PubMed

Dal Santo, Silvia; Palliotti, Alberto; Zenoni, Sara; Tornielli, Giovanni Battista; Fasoli, Marianna; Paci, Paola; Tombesi, Sergio; Frioni, Tommaso; Silvestroni, Oriana; Bellincontro, Andrea; d'Onofrio, Claudio; Matarese, Fabiola; Gatti, Matteo; Poni, Stefano; Pezzotti, Mario

2016-10-20

Grapevine (Vitis vinifera L.) is an economically important crop with a wide geographical distribution, reflecting its ability to grow successfully in a range of climates. However, many vineyards are located in regions with seasonal drought, and these are often predicted to be global climate change hotspots. Climate change affects the entire physiology of grapevine, with strong effects on yield, wine quality and typicity, making it difficult to produce berries of optimal enological quality and consistent stability over the forthcoming decades. Here we investigated the reactions of two grapevine cultivars to water stress, the isohydric variety Montepulciano and the anisohydric variety Sangiovese, by examining physiological and molecular perturbations in the leaf and berry. A multidisciplinary approach was used to characterize the distinct stomatal behavior of the two cultivars and its impact on leaf and berry gene expression. Positive associations were found among the photosynthetic, physiological and transcriptional modifications, and candidate genes encoding master regulators of the water stress response were identified using an integrated approach based on the analysis of topological co-expression network properties. In particular, the genome-wide transcriptional study indicated that the isohydric behavior relies upon the following responses: i) faster transcriptome response after stress imposition; ii) faster abscisic acid-related gene modulation; iii) more rapid expression of heat shock protein (HSP) genes and iv) reversion of gene-expression profile at rewatering. Conversely, that reactive oxygen species (ROS)-scavenging enzymes, molecular chaperones and abiotic stress-related genes were induced earlier and more strongly in the anisohydric cultivar. Overall, the present work found original evidence of a molecular basis for the proposed classification between isohydric and anisohydric grapevine genotypes.

Uncovering a Dual Regulatory Role for Caspases During Endoplasmic Reticulum Stress-induced Cell Death

PubMed Central

Anania, Veronica G.; Yu, Kebing; Gnad, Florian; Pferdehirt, Rebecca R.; Li, Han; Ma, Taylur P.; Jeon, Diana; Fortelny, Nikolaus; Forrest, William; Ashkenazi, Avi; Overall, Christopher M.; Lill, Jennie R.

2016-01-01

Many diseases are associated with endoplasmic reticulum (ER) stress, which results from an accumulation of misfolded proteins. This triggers an adaptive response called the “unfolded protein response” (UPR), and prolonged exposure to ER stress leads to cell death. Caspases are reported to play a critical role in ER stress-induced cell death but the underlying mechanisms by which they exert their effect continue to remain elusive. To understand the role caspases play during ER stress, a systems level approach integrating analysis of the transcriptome, proteome, and proteolytic substrate profile was employed. This quantitative analysis revealed transcriptional profiles for most human genes, provided information on protein abundance for 4476 proteins, and identified 445 caspase substrates. Based on these data sets many caspase substrates were shown to be downregulated at the protein level during ER stress suggesting caspase activity inhibits their cellular function. Additionally, RNA sequencing revealed a role for caspases in regulation of ER stress-induced transcriptional pathways and gene set enrichment analysis showed expression of multiple gene targets of essential transcription factors to be upregulated during ER stress upon inhibition of caspases. Furthermore, these transcription factors were degraded in a caspase-dependent manner during ER stress. These results indicate that caspases play a dual role in regulating the cellular response to ER stress through both post-translational and transcriptional regulatory mechanisms. Moreover, this study provides unique insight into progression of the unfolded protein response into cell death, which may help identify therapeutic strategies to treat ER stress-related diseases. PMID:27125827

Characterisation of transcriptional responses to dioxins and dioxin-like contaminants in roach (Rutilus rutilus) using whole transcriptome analysis.

PubMed

Brinkmann, Markus; Koglin, Sven; Eisner, Bryanna; Wiseman, Steve; Hecker, Markus; Eichbaum, Kathrin; Thalmann, Beat; Buchinger, Sebastian; Reifferscheid, Georg; Hollert, Henner

2016-01-15

There is significant concern regarding the contamination of riverine sediments with dioxins and dioxin-like compounds (DLCs), including polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) and some polycyclic aromatic hydrocarbons (PAHs). The majority of studies investigating the ecotoxicology of DLCs in fish have focused on a few standard model species. However, there is significant uncertainty as to whether these model species are representative of native river fish, particularly in Europe. In this study, the transcriptional responses following exposure to equipotent concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), PCB 156 or the dioxin-like PAH, benzo[k]fluoranthene (BkF), were investigated in juvenile roach (Rutilus rutilus), a fish species that constitutes a large proportion of the fish biomass in freshwater bodies throughout Europe. To this end, RNA sequencing analysis was used to comprehensively characterise the molecular mechanisms and pathways of toxicity of these DLCs. Whole transcriptome analyses using ClueGO software revealed that DLCs have the potential to disrupt a number of important processes, including energy metabolism, oogenesis, the immune system, apoptosis and the response to oxidative stress. However, despite using equipotent concentrations, there was very little conservation of the transcriptional responses observed in fish exposed to different DLCs. TCDD provoked significant specific changes in the levels of transcripts related to immunotoxicity and carbohydrate metabolism, while PCB 156 caused virtually no specific effects. Exposure to BkF affected the most diverse suite of molecular functions and biological processes, including blood coagulation, oxidative stress responses, unspecific responses to organic or inorganic substances/stimuli, cellular redox homeostasis and specific receptor pathways. To our knowledge, this is the first study of the transcriptome-wide effects of different classes of DLCs in fish. These findings represent an important step towards describing complete toxicity pathways of DLCs, which will be important in the context of informing risk assessments of DLC toxicity in native fish species. Copyright © 2015 Elsevier B.V. All rights reserved.

Combined Cytological and Transcriptomic Analysis Reveals a Nitric Oxide Signaling Pathway Involved in Cold-Inhibited Camellia sinensis Pollen Tube Growth

PubMed Central

Wang, Weidong; Sheng, Xianyong; Shu, Zaifa; Li, Dongqin; Pan, Junting; Ye, Xiaoli; Chang, Pinpin; Li, Xinghui; Wang, Yuhua

2016-01-01

Nitric oxide (NO) as a signaling molecule plays crucial roles in many abiotic stresses in plant development processes, including pollen tube growth. Here, the signaling networks dominated by NO during cold stress that inhibited Camellia sinensis pollen tube growth are investigated in vitro. Cytological analysis show that cold-induced NO is involved in the inhibition of pollen tube growth along with disruption of the cytoplasmic Ca2+ gradient, increase in ROS content, acidification of cytoplasmic pH and abnormalities in organelle ultrastructure and cell wall component distribution in the pollen tube tip. Furthermore, differentially expressed genes (DEGs)-related to signaling pathway, such as NO synthesis, cGMP, Ca2+, ROS, pH, actin, cell wall, and MAPK cascade signal pathways, are identified and quantified using transcriptomic analyses and qRT-PCR, which indicate a potential molecular mechanism for the above cytological results. Taken together, these findings suggest that a complex signaling network dominated by NO, including Ca2+, ROS, pH, RACs signaling and the crosstalk among them, is stimulated in the C. sinensis pollen tube in response to cold stress, which further causes secondary and tertiary alterations, such as ultrastructural abnormalities in organelles and cell wall construction, ultimately resulting in perturbed pollen tube extension. PMID:27148289

Comparison of the Transcriptomes of Ginger (Zingiber officinale Rosc.) and Mango Ginger (Curcuma amada Roxb.) in Response to the Bacterial Wilt Infection

PubMed Central

Prasath, Duraisamy; Karthika, Raveendran; Habeeba, Naduva Thadath; Suraby, Erinjery Jose; Rosana, Ottakandathil Babu; Shaji, Avaroth; Eapen, Santhosh Joseph; Deshpande, Uday; Anandaraj, Muthuswamy

2014-01-01

Bacterial wilt in ginger (Zingiber officinale Rosc.) caused by Ralstonia solanacearum is one of the most important production constraints in tropical, sub-tropical and warm temperature regions of the world. Lack of resistant genotype adds constraints to the crop management. However, mango ginger (Curcuma amada Roxb.), which is resistant to R. solanacearum, is a potential donor, if the exact mechanism of resistance is understood. To identify genes involved in resistance to R. solanacearum, we have sequenced the transcriptome from wilt-sensitive ginger and wilt-resistant mango ginger using Illumina sequencing technology. A total of 26387032 and 22268804 paired-end reads were obtained after quality filtering for C. amada and Z. officinale, respectively. A total of 36359 and 32312 assembled transcript sequences were obtained from both the species. The functions of the unigenes cover a diverse set of molecular functions and biological processes, among which we identified a large number of genes associated with resistance to stresses and response to biotic stimuli. Large scale expression profiling showed that many of the disease resistance related genes were expressed more in C. amada. Comparative analysis also identified genes belonging to different pathways of plant defense against biotic stresses that are differentially expressed in either ginger or mango ginger. The identification of many defense related genes differentially expressed provides many insights to the resistance mechanism to R. solanacearum and for studying potential pathways involved in responses to pathogen. Also, several candidate genes that may underline the difference in resistance to R. solanacearum between ginger and mango ginger were identified. Finally, we have developed a web resource, ginger transcriptome database, which provides public access to the data. Our study is among the first to demonstrate the use of Illumina short read sequencing for de novo transcriptome assembly and comparison in non-model species of Zingiberaceae. PMID:24940878

Comparison of the transcriptomes of ginger (Zingiber officinale Rosc.) and mango ginger (Curcuma amada Roxb.) in response to the bacterial wilt infection.

PubMed

Prasath, Duraisamy; Karthika, Raveendran; Habeeba, Naduva Thadath; Suraby, Erinjery Jose; Rosana, Ottakandathil Babu; Shaji, Avaroth; Eapen, Santhosh Joseph; Deshpande, Uday; Anandaraj, Muthuswamy

2014-01-01

Bacterial wilt in ginger (Zingiber officinale Rosc.) caused by Ralstonia solanacearum is one of the most important production constraints in tropical, sub-tropical and warm temperature regions of the world. Lack of resistant genotype adds constraints to the crop management. However, mango ginger (Curcuma amada Roxb.), which is resistant to R. solanacearum, is a potential donor, if the exact mechanism of resistance is understood. To identify genes involved in resistance to R. solanacearum, we have sequenced the transcriptome from wilt-sensitive ginger and wilt-resistant mango ginger using Illumina sequencing technology. A total of 26387032 and 22268804 paired-end reads were obtained after quality filtering for C. amada and Z. officinale, respectively. A total of 36359 and 32312 assembled transcript sequences were obtained from both the species. The functions of the unigenes cover a diverse set of molecular functions and biological processes, among which we identified a large number of genes associated with resistance to stresses and response to biotic stimuli. Large scale expression profiling showed that many of the disease resistance related genes were expressed more in C. amada. Comparative analysis also identified genes belonging to different pathways of plant defense against biotic stresses that are differentially expressed in either ginger or mango ginger. The identification of many defense related genes differentially expressed provides many insights to the resistance mechanism to R. solanacearum and for studying potential pathways involved in responses to pathogen. Also, several candidate genes that may underline the difference in resistance to R. solanacearum between ginger and mango ginger were identified. Finally, we have developed a web resource, ginger transcriptome database, which provides public access to the data. Our study is among the first to demonstrate the use of Illumina short read sequencing for de novo transcriptome assembly and comparison in non-model species of Zingiberaceae.

Spaceflight modulates gene expression in the whole blood of astronauts.

PubMed

Barrila, Jennifer; Ott, C Mark; LeBlanc, Carly; Mehta, Satish K; Crabbé, Aurélie; Stafford, Phillip; Pierson, Duane L; Nickerson, Cheryl A

2016-01-01

Astronauts are exposed to a unique combination of stressors during spaceflight, which leads to alterations in their physiology and potentially increases their susceptibility to disease, including infectious diseases. To evaluate the potential impact of the spaceflight environment on the regulation of molecular pathways mediating cellular stress responses, we performed a first-of-its-kind pilot study to assess spaceflight-related gene-expression changes in the whole blood of astronauts. Using an array comprised of 234 well-characterized stress-response genes, we profiled transcriptomic changes in six astronauts (four men and two women) from blood preserved before and immediately following the spaceflight. Differentially regulated transcripts included those important for DNA repair, oxidative stress, and protein folding/degradation, including HSP90AB1 , HSP27 , GPX1 , XRCC1 , BAG-1 , HHR23A , FAP48 , and C-FOS . No gender-specific differences or relationship to number of missions flown was observed. This study provides a first assessment of transcriptomic changes occurring in the whole blood of astronauts in response to spaceflight.

Spaceflight modulates gene expression in the whole blood of astronauts

PubMed Central

Barrila, Jennifer; Ott, C Mark; LeBlanc, Carly; Mehta, Satish K; Crabbé, Aurélie; Stafford, Phillip; Pierson, Duane L; Nickerson, Cheryl A

2016-01-01

Astronauts are exposed to a unique combination of stressors during spaceflight, which leads to alterations in their physiology and potentially increases their susceptibility to disease, including infectious diseases. To evaluate the potential impact of the spaceflight environment on the regulation of molecular pathways mediating cellular stress responses, we performed a first-of-its-kind pilot study to assess spaceflight-related gene-expression changes in the whole blood of astronauts. Using an array comprised of 234 well-characterized stress-response genes, we profiled transcriptomic changes in six astronauts (four men and two women) from blood preserved before and immediately following the spaceflight. Differentially regulated transcripts included those important for DNA repair, oxidative stress, and protein folding/degradation, including HSP90AB1, HSP27, GPX1, XRCC1, BAG-1, HHR23A, FAP48, and C-FOS. No gender-specific differences or relationship to number of missions flown was observed. This study provides a first assessment of transcriptomic changes occurring in the whole blood of astronauts in response to spaceflight. PMID:28725744

Genome-wide characterization and analysis of bZIP transcription factor gene family related to abiotic stress in cassava.

PubMed

Hu, Wei; Yang, Hubiao; Yan, Yan; Wei, Yunxie; Tie, Weiwei; Ding, Zehong; Zuo, Jiao; Peng, Ming; Li, Kaimian

2016-03-07

The basic leucine zipper (bZIP) transcription factor family plays crucial roles in various aspects of biological processes. Currently, no information is available regarding the bZIP family in the important tropical crop cassava. Herein, 77 bZIP genes were identified from cassava. Evolutionary analysis indicated that MebZIPs could be divided into 10 subfamilies, which was further supported by conserved motif and gene structure analyses. Global expression analysis suggested that MebZIPs showed similar or distinct expression patterns in different tissues between cultivated variety and wild subspecies. Transcriptome analysis of three cassava genotypes revealed that many MebZIP genes were activated by drought in the root of W14 subspecies, indicating the involvement of these genes in the strong resistance of cassava to drought. Expression analysis of selected MebZIP genes in response to osmotic, salt, cold, ABA, and H2O2 suggested that they might participate in distinct signaling pathways. Our systematic analysis of MebZIPs reveals constitutive, tissue-specific and abiotic stress-responsive candidate MebZIP genes for further functional characterization in planta, yields new insights into transcriptional regulation of MebZIP genes, and lays a foundation for understanding of bZIP-mediated abiotic stress response.

Tissue-Specific Transcriptomics Reveals an Important Role of the Unfolded Protein Response in Maintaining Fertility upon Heat Stress in Arabidopsis.

PubMed

Zhang, Shuang-Shuang; Yang, Hongxing; Ding, Lan; Song, Ze-Ting; Ma, Hong; Chang, Fang; Liu, Jian-Xiang

2017-05-01

High temperatures have a great impact on plant reproductive development and subsequent fruit and seed set, but the underlying molecular mechanisms are not well understood. We used transcriptome profiling to investigate the effect of heat stress on reproductive development of Arabidopsis thaliana plants and observed distinct response patterns in vegetative versus reproductive tissues. Exposure to heat stress affected reproductive developmental programs, including early phases of anther/ovule development and meiosis. Also, genes participating in the unfolded protein response (UPR) were enriched in the reproductive tissue-specific genes that were upregulated by heat. Moreover, we found that the UPR-deficient bzip28 bzip60 double mutant was sensitive to heat stresses and had reduced silique length and fertility. Comparison of heat-responsive wild type versus bzip28 bzip60 plants identified 521 genes that were regulated by bZIP28 and bZIP60 upon heat stress during reproductive stages, most of which were noncanonical UPR genes. Chromatin immunoprecipitation coupled with high-throughput sequencing analyses revealed 133 likely direct targets of bZIP28 in Arabidopsis seedlings subjected to heat stress, including 27 genes that were also upregulated by heat during reproductive development. Our results provide important insights into heat responsiveness in Arabidopsis reproductive tissues and demonstrate the protective roles of the UPR for maintaining fertility upon heat stress. © 2017 American Society of Plant Biologists. All rights reserved.

Transcriptome profiling of Galaxea fascicularis and its endosymbiont Symbiodinium reveals chronic eutrophication tolerance pathways and metabolic mutualism between partners

PubMed Central

Lin, Zhenyue; Chen, Mingliang; Dong, Xu; Zheng, Xinqing; Huang, Haining; Xu, Xun; Chen, Jianming

2017-01-01

In the South China Sea, coastal eutrophication in the Beibu Gulf has seriously threatened reef habitats by subjecting corals to chronic physiological stress. To determine how coral holobionts may tolerate such conditions, we examined the transcriptomes of healthy colonies of the galaxy coral Galaxea fascicularis and its endosymbiont Symbiodinium from two reef sites experiencing pristine or eutrophied nutrient regimes. We identified 236 and 205 genes that were differentially expressed in eutrophied hosts and symbionts, respectively. Both gene sets included pathways related to stress responses and metabolic interactions. An analysis of genes originating from each partner revealed striking metabolic integration with respect to vitamins, cofactors, amino acids, fatty acids, and secondary metabolite biosynthesis. The expression levels of these genes supported the existence of a continuum of mutualism in this coral-algal symbiosis. Additionally, large sets of transcription factors, cell signal transduction molecules, biomineralization components, and galaxin-related proteins were expanded in G. fascicularis relative to other coral species. PMID:28181581

Sex Differences in Nucleus Accumbens Transcriptome Profiles Associated with Susceptibility versus Resilience to Subchronic Variable Stress.

PubMed

Hodes, Georgia E; Pfau, Madeline L; Purushothaman, Immanuel; Ahn, H Francisca; Golden, Sam A; Christoffel, Daniel J; Magida, Jane; Brancato, Anna; Takahashi, Aki; Flanigan, Meghan E; Ménard, Caroline; Aleyasin, Hossein; Koo, Ja Wook; Lorsch, Zachary S; Feng, Jian; Heshmati, Mitra; Wang, Minghui; Turecki, Gustavo; Neve, Rachel; Zhang, Bin; Shen, Li; Nestler, Eric J; Russo, Scott J

2015-12-16

Depression and anxiety disorders are more prevalent in females, but the majority of research in animal models, the first step in finding new treatments, has focused predominantly on males. Here we report that exposure to subchronic variable stress (SCVS) induces depression-associated behaviors in female mice, whereas males are resilient as they do not develop these behavioral abnormalities. In concert with these different behavioral responses, transcriptional analysis of nucleus accumbens (NAc), a major brain reward region, by use of RNA sequencing (RNA-seq) revealed markedly different patterns of stress regulation of gene expression between the sexes. Among the genes displaying sex differences was DNA methyltransferase 3a (Dnmt3a), which shows a greater induction in females after SCVS. Interestingly, Dnmt3a expression levels were increased in the NAc of depressed humans, an effect seen in both males and females. Local overexpression of Dnmt3a in NAc rendered male mice more susceptible to SCVS, whereas Dnmt3a knock-out in this region rendered females more resilient, directly implicating this gene in stress responses. Associated with this enhanced resilience of female mice upon NAc knock-out of Dnmt3a was a partial shift of the NAc female transcriptome toward the male pattern after SCVS. These data indicate that males and females undergo different patterns of transcriptional regulation in response to stress and that a DNA methyltransferase in NAc contributes to sex differences in stress vulnerability. Women have a higher incidence of depression than men. However, preclinical models, the first step in developing new diagnostics and therapeutics, have been performed mainly on male subjects. Using a stress-based animal model of depression that causes behavioral effects in females but not males, we demonstrate a sex-specific transcriptional profile in brain reward circuitry. This transcriptional profile can be altered by removal of an epigenetic mechanism, which normally suppresses DNA transcription, creating a hybrid male/female transcriptional pattern. Removal of this epigenetic mechanism also induces behavioral resilience to stress in females. These findings shed new light onto molecular factors controlling sex differences in stress response. Copyright © 2015 the authors 0270-6474/15/3516363-15$15.00/0.

Sex Differences in Nucleus Accumbens Transcriptome Profiles Associated with Susceptibility versus Resilience to Subchronic Variable Stress

PubMed Central

Hodes, Georgia E.; Pfau, Madeline L.; Purushothaman, Immanuel; Ahn, H. Francisca; Golden, Sam A.; Christoffel, Daniel J.; Magida, Jane; Brancato, Anna; Takahashi, Aki; Flanigan, Meghan E.; Ménard, Caroline; Aleyasin, Hossein; Koo, Ja Wook; Lorsch, Zachary S.; Feng, Jian; Heshmati, Mitra; Wang, Minghui; Turecki, Gustavo; Neve, Rachel; Zhang, Bin; Shen, Li; Nestler, Eric J.

2015-01-01

Depression and anxiety disorders are more prevalent in females, but the majority of research in animal models, the first step in finding new treatments, has focused predominantly on males. Here we report that exposure to subchronic variable stress (SCVS) induces depression-associated behaviors in female mice, whereas males are resilient as they do not develop these behavioral abnormalities. In concert with these different behavioral responses, transcriptional analysis of nucleus accumbens (NAc), a major brain reward region, by use of RNA sequencing (RNA-seq) revealed markedly different patterns of stress regulation of gene expression between the sexes. Among the genes displaying sex differences was DNA methyltransferase 3a (Dnmt3a), which shows a greater induction in females after SCVS. Interestingly, Dnmt3a expression levels were increased in the NAc of depressed humans, an effect seen in both males and females. Local overexpression of Dnmt3a in NAc rendered male mice more susceptible to SCVS, whereas Dnmt3a knock-out in this region rendered females more resilient, directly implicating this gene in stress responses. Associated with this enhanced resilience of female mice upon NAc knock-out of Dnmt3a was a partial shift of the NAc female transcriptome toward the male pattern after SCVS. These data indicate that males and females undergo different patterns of transcriptional regulation in response to stress and that a DNA methyltransferase in NAc contributes to sex differences in stress vulnerability. SIGNIFICANCE STATEMENT Women have a higher incidence of depression than men. However, preclinical models, the first step in developing new diagnostics and therapeutics, have been performed mainly on male subjects. Using a stress-based animal model of depression that causes behavioral effects in females but not males, we demonstrate a sex-specific transcriptional profile in brain reward circuitry. This transcriptional profile can be altered by removal of an epigenetic mechanism, which normally suppresses DNA transcription, creating a hybrid male/female transcriptional pattern. Removal of this epigenetic mechanism also induces behavioral resilience to stress in females. These findings shed new light onto molecular factors controlling sex differences in stress response. PMID:26674863

Time of day determines Arabidopsis transcriptome and growth dynamics under mild drought.

PubMed

Dubois, Marieke; Claeys, Hannes; Van den Broeck, Lisa; Inzé, Dirk

2017-02-01

Drought stress is a major problem for agriculture worldwide, causing significant yield losses. Plants have developed highly flexible mechanisms to deal with drought, including organ- and developmental stage-specific responses. In young leaves, growth is repressed as an active mechanism to save water and energy, increasing the chances of survival but decreasing yield. Despite its importance, the molecular basis for this growth inhibition is largely unknown. Here, we present a novel approach to explore early molecular mechanisms controlling Arabidopsis leaf growth inhibition following mild drought. We found that growth and transcriptome responses to drought are highly dynamic. Growth was only repressed by drought during the day, and our evidence suggests that this may be due to gating by the circadian clock. Similarly, time of day strongly affected the extent, specificity, and in certain cases even direction of drought-induced changes in gene expression. These findings underscore the importance of taking into account diurnal patterns to understand stress responses, as only a small core of drought-responsive genes are affected by drought at all times of the day. Finally, we leveraged our high-resolution data to demonstrate that phenotypic and transcriptome responses can be matched to identify putative novel regulators of growth under mild drought. © 2016 The Authors Plant, Cell & Environment Published by John Wiley & Sons Ltd.

Rice tolerance to suboptimal low temperatures relies on the maintenance of the photosynthetic capacity.

PubMed

Gazquez, Ayelén; Vilas, Juan Manuel; Colman Lerner, Jorge Esteban; Maiale, Santiago Javier; Calzadilla, Pablo Ignacio; Menéndez, Ana Bernardina; Rodríguez, Andrés Alberto

2018-06-01

The purpose of this research was to identify differences between two contrasting rice cultivars in their response to suboptimal low temperatures stress. A transcriptomic analysis of the seedlings was performed and results were complemented with biochemical and physiological analyses. The microarray analysis showed downregulation of many genes related with PSII and particularly with the oxygen evolving complex in the sensitive cultivar IR50. Complementary studies indicated that the PSII performance, the degree of oxygen evolving complex coupling with the PSII core and net photosynthetic rate diminished in this cultivar in response to the stress. However, the tolerant cultivar Koshihikari was able to maintain its energy equilibrium by sustaining the photosynthetic capacity. The increase of oleic acid in Koshihikari could be related with membrane remodelling of the chloroplasts and hence contribute to tolerance. Overall, these results work as a ground for future analyses that look forward to characterize possible mechanisms to tolerate this stress. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

High throughput sequencing identifies chilling responsive genes in sweetpotato (Ipomoea batatas Lam.) during storage.

PubMed

Xie, Zeyi; Zhou, Zhilin; Li, Hongmin; Yu, Jingjing; Jiang, Jiaojiao; Tang, Zhonghou; Ma, Daifu; Zhang, Baohong; Han, Yonghua; Li, Zongyun

2018-05-21

Sweetpotato (Ipomoea batatas L.) is a globally important economic food crop. It belongs to Convolvulaceae family and origins in the tropics; however, sweetpotato is sensitive to cold stress during storage. In this study, we performed transcriptome sequencing to investigate the sweetpotato response to chilling stress during storage. A total of 110,110 unigenes were generated via high-throughput sequencing. Differentially expressed genes (DEGs) analysis showed that 18,681 genes were up-regulated and 21,983 genes were down-regulated in low temperature condition. Many DEGs were related to the cell membrane system, antioxidant enzymes, carbohydrate metabolism, and hormone metabolism, which are potentially associated with sweetpotato resistance to low temperature. The existence of DEGs suggests a molecular basis for the biochemical and physiological consequences of sweetpotato in low temperature storage conditions. Our analysis will provide a new target for enhancement of sweetpotato cold stress tolerance in postharvest storage through genetic manipulation. Copyright © 2018. Published by Elsevier Inc.

An integrative transcriptomic approach to identify depot differences in genes and microRNAs in adipose tissues from high fat fed mice.

PubMed

Wijayatunga, Nadeeja N; Pahlavani, Mandana; Kalupahana, Nishan S; Kottapalli, Kameswara Rao; Gunaratne, Preethi H; Coarfa, Cristian; Ramalingam, Latha; Moustaid-Moussa, Naima

2018-02-06

Obesity contributes to metabolic disorders such as diabetes and cardiovascular disease. Characterization of differences between the main adipose tissue depots, white (WAT) [including subcutaneous (SAT) and visceral adipose tissue (VAT)] and brown adipose tissue (BAT) helps to identify their roles in obesity. Thus, we studied depot-specific differences in whole transcriptome and miRNA profiles of SAT, VAT and BAT from high fat diet (HFD/45% of calories from fat) fed mice using RNA sequencing and small RNA-Seq. Using quantitative real-time polymerase chain reaction, we validated depot-specific differences in endoplasmic reticulum (ER) stress related genes and miRNAs using mice fed a HFD vs. low fat diet (LFD/10% of calories from fat). According to the transcriptomic analysis, lipogenesis, adipogenesis, inflammation, endoplasmic reticulum (ER) stress and unfolded protein response (UPR) were higher in VAT compared to BAT, whereas energy expenditure, fatty acid oxidation and oxidative phosphorylation were higher in BAT than in VAT of the HFD fed mice. In contrast to BAT, ER stress marker genes were significantly upregulated in VAT of HFD fed mice than the LFD fed mice. For the first time, we report depot specific differences in ER stress related miRNAs including; downregulation of miR-125b-5p, upregulation miR-143-3p, and miR-222-3p in VAT following HFD and upregulation of miR-30c-2-3p only in BAT following a HFD in mice than the LFD mice. In conclusion, HFD differentially regulates miRNAs and genes in different adipose depots with significant induction of genes related to lipogenesis, adipogenesis, inflammation, ER stress, and UPR in WAT compared to BAT.

Proteomics of drug resistance in Candida glabrata biofilms.

PubMed

Seneviratne, C Jayampath; Wang, Yu; Jin, Lijian; Abiko, Y; Samaranayake, Lakshman P

2010-04-01

Candida glabrata is a fungal pathogen that causes a variety of mucosal and systemic infections among compromised patient populations with higher mortality rates. Previous studies have shown that biofilm mode of the growth of the fungus is highly resistant to antifungal agents compared with the free-floating or planktonic mode of growth. Therefore, in the present study, we used 2-D DIGE to evaluate the differential proteomic profiles of C. glabrata under planktonic and biofilm modes of growth. Candida glabrata biofilms were developed on polystyrene surfaces and age-matched planktonic cultures were obtained in parallel. Initially, biofilm architecture, viability, and antifungal susceptibility were evaluated. Differentially expressed proteins more than 1.5-fold in DIGE analysis were subjected to MS/MS. The transcriptomic regulation of these biomarkers was evaluated by quantitative real-time PCR. Candida glabrata biofilms were highly resistant to the antifungals and biocides compared with the planktonic mode of growth. Candida glabrata biofilm proteome when compared with its planktonic proteome showed upregulation of stress response proteins, while glycolysis enzymes were downregulated. Similar trend could be observed at transcriptomic level. In conclusion, C. glabrata biofilms possess higher amount of stress response proteins, which may potentially contribute to the higher antifungal resistance seen in C. glabrata biofilms.

Genome-wide analyses of the bZIP family reveal their involvement in the development, ripening and abiotic stress response in banana

PubMed Central

Hu, Wei; Wang, Lianzhe; Tie, Weiwei; Yan, Yan; Ding, Zehong; Liu, Juhua; Li, Meiying; Peng, Ming; Xu, Biyu; Jin, Zhiqiang

2016-01-01

The leucine zipper (bZIP) transcription factors play important roles in multiple biological processes. However, less information is available regarding the bZIP family in the important fruit crop banana. In this study, 121 bZIP transcription factor genes were identified in the banana genome. Phylogenetic analysis showed that MabZIPs were classified into 11 subfamilies. The majority of MabZIP genes in the same subfamily shared similar gene structures and conserved motifs. The comprehensive transcriptome analysis of two banana genotypes revealed the differential expression patterns of MabZIP genes in different organs, in various stages of fruit development and ripening, and in responses to abiotic stresses, including drought, cold, and salt. Interaction networks and co-expression assays showed that group A MabZIP-mediated networks participated in various stress signaling, which was strongly activated in Musa ABB Pisang Awak. This study provided new insights into the complicated transcriptional control of MabZIP genes and provided robust tissue-specific, development-dependent, and abiotic stress-responsive candidate MabZIP genes for potential applications in the genetic improvement of banana cultivars. PMID:27445085

Leveraging Genetic-Background Effects in Saccharomyces cerevisiae To Improve Lignocellulosic Hydrolysate Tolerance

DOE PAGES

Sardi, Maria; Rovinskiy, Nikolay; Zhang, Yaoping; ...

2016-07-22

We report a major obstacle to sustainable lignocellulosic biofuel production is microbe inhibition by the combinatorial stresses in pretreated plant hydrolysate. Chemical biomass pretreatment releases a suite of toxins that interact with other stressors, including high osmolarity and temperature, which together can have poorly understood synergistic effects on cells. Improving tolerance in industrial strains has been hindered, in part because the mechanisms of tolerance reported in the literature often fail to recapitulate in other strain backgrounds. Here, we explored and then exploited variations in stress tolerance, toxin-induced transcriptomic responses, and fitness effects of gene overexpression in different Saccharomyces cerevisiae (yeast)more » strains to identify genes and processes linked to tolerance of hydrolysate stressors. Using six different S. cerevisiae strains that together maximized phenotypic and genetic diversity, first we explored transcriptomic differences between resistant and sensitive strains to identify common and strain-specific responses. This comparative analysis implicated primary cellular targets of hydrolysate toxins, secondary effects of defective defense strategies, and mechanisms of tolerance. Dissecting the responses to individual hydrolysate components across strains pointed to synergistic interactions between osmolarity, pH, hydrolysate toxins, and nutrient composition. By characterizing the effects of high-copy gene overexpression in three different strains, we revealed the breadth of the background-specific effects of gene fitness contributions in synthetic hydrolysate. Lastly, our approach identified new genes for engineering improved stress tolerance in diverse strains while illuminating the effects of genetic background on molecular mechanisms.« less

Transcriptome Sequence and Plasmid Copy Number Analysis of the Brewery Isolate Pediococcus claussenii ATCC BAA-344T during Growth in Beer

PubMed Central

Pittet, Vanessa; Phister, Trevor G.; Ziola, Barry

2013-01-01

Growth of specific lactic acid bacteria in beer leads to spoiled product and economic loss for the brewing industry. Microbial growth is typically inhibited by the combined stresses found in beer (e.g., ethanol, hops, low pH, minimal nutrients); however, certain bacteria have adapted to grow in this harsh environment. Considering little is known about the mechanisms used by bacteria to grow in and spoil beer, transcriptome sequencing was performed on a variant of the beer-spoilage organism Pediococcus claussenii ATCC BAA-344T (Pc344-358). Illumina sequencing was used to compare the transcript levels in Pc344-358 growing mid-exponentially in beer to those in nutrient-rich MRS broth. Various operons demonstrated high gene expression in beer, several of which are involved in nutrient acquisition and overcoming the inhibitory effects of hop compounds. As well, genes functioning in cell membrane modification and biosynthesis demonstrated significantly higher transcript levels in Pc344-358 growing in beer. Three plasmids had the majority of their genes showing increased transcript levels in beer, whereas the two cryptic plasmids showed slightly decreased gene expression. Follow-up analysis of plasmid copy number in both growth environments revealed similar trends, where more copies of the three non-cryptic plasmids were found in Pc344-358 growing in beer. Transcriptome sequencing also enabled the addition of several genes to the P . claussenii ATCC BAA-344T genome annotation, some of which are putatively transcribed as non-coding RNAs. The sequencing results not only provide the first transcriptome description of a beer-spoilage organism while growing in beer, but they also highlight several targets for future exploration, including genes that may have a role in the general stress response of lactic acid bacteria. PMID:24040005

Transcriptomic analysis of the response of Pseudomonas fluorescens to epigallocatechin gallate by RNA-seq

PubMed Central

Liu, Xiaoxiang; Shen, Bimiao; Du, Peng; Wang, Nan; Wang, Jiaxue; Li, Jianrong

2017-01-01

Epigallocatechin gallate (EGCG) is a main constituent of green tea polyphenols that are widely used as food preservatives and are considered to be safe for consumption. However, the underlying antimicrobial mechanism of EGCG and the bacterial response to EGCG are not clearly understood. In the present study, a genome-wide transcriptional analysis of a typical spoilage bacterium, Pseudomonas fluorescens that responded to EGCG was performed using RNA-seq technology. A total of 26,365,414 and 23,287,092 clean reads were generated from P. fluorescens treated with or without 1 mM EGCG and the clean reads were aligned to the reference genome. Differential expression analysis revealed 291 upregulated genes and 134 downregulated genes and the differentially expressed genes (DEGs) were verified using RT-qPCR. Most of the DGEs involved in iron uptake, antioxidation, DNA repair, efflux system, cell envelope and cell-surface component synthesis were significantly upregulated by EGCG treatment, while most genes associated with energy production were downregulated. These transcriptomic changes are likely to be adaptive responses of P. fluorescens to iron limitation and oxidative stress, as well as DNA and envelope damage caused by EGCG. The expression of specific genes encoding the extra-cytoplasmic function sigma factor (PvdS, RpoE and AlgU) and the two-component sensor histidine kinase (BaeS and RpfG) were markedly changed by EGCG treatment, which may play important roles in regulating the stress responses of P. fluorescens to EGCG. The present data provides important insights into the molecular action of EGCG and the possible cross-resistance mediated by EGCG on P. fluorescens, which may ultimately contribute to the optimal application of green tea polyphenols in food preservation. PMID:28545064

Microbiome and ecotypic adaption of Holcus lanatus (L.) to extremes of its soil pH range, investigated through transcriptome sequencing.

PubMed

Young, Ellen; Carey, Manus; Meharg, Andrew A; Meharg, Caroline

2018-03-20

Plants can adapt to edaphic stress, such as nutrient deficiency, toxicity and biotic challenges, by controlled transcriptomic responses, including microbiome interactions. Traditionally studied in model plant species with controlled microbiota inoculation treatments, molecular plant-microbiome interactions can be functionally investigated via RNA-Seq. Complex, natural plant-microbiome studies are limited, typically focusing on microbial rRNA and omitting functional microbiome investigations, presenting a fundamental knowledge gap. Here, root and shoot meta-transcriptome analyses, in tandem with shoot elemental content and root staining, were employed to investigate transcriptome responses in the wild grass Holcus lanatus and its associated natural multi-species eukaryotic microbiome. A full factorial reciprocal soil transplant experiment was employed, using plant ecotypes from two widely contrasting natural habitats, acid bog and limestone quarry soil, to investigate naturally occurring, and ecologically meaningful, edaphically driven molecular plant-microbiome interactions. Arbuscular mycorrhizal (AM) and non-AM fungal colonization was detected in roots in both soils. Staining showed greater levels of non-AM fungi, and transcriptomics indicated a predominance of Ascomycota-annotated genes. Roots in acid bog soil were dominated by Phialocephala-annotated transcripts, a putative growth-promoting endophyte, potentially involved in N nutrition and ion homeostasis. Limestone roots in acid bog soil had greater expression of other Ascomycete genera and Oomycetes and lower expression of Phialocephala-annotated transcripts compared to acid ecotype roots, which corresponded with reduced induction of pathogen defense processes, particularly lignin biosynthesis in limestone ecotypes. Ascomycota dominated in shoots and limestone soil roots, but Phialocephala-annotated transcripts were insignificant, and no single Ascomycete genus dominated. Fusarium-annotated transcripts were the most common genus in shoots, with Colletotrichum and Rhizophagus (AM fungi) most numerous in limestone soil roots. The latter coincided with upregulation of plant genes involved in AM symbiosis initiation and AM-based P acquisition in an environment where P availability is low. Meta-transcriptome analyses provided novel insights into H. lanatus transcriptome responses, associated eukaryotic microbiota functions and taxonomic community composition. Significant edaphic and plant ecotype effects were identified, demonstrating that meta-transcriptome-based functional analysis is a powerful tool for the study of natural plant-microbiome interactions.

Transcriptome-Wide Survey and Expression Profile Analysis of Putative Chrysanthemum HD-Zip I and II Genes

PubMed Central

Song, Aiping; Li, Peiling; Xin, Jingjing; Chen, Sumei; Zhao, Kunkun; Wu, Dan; Fan, Qingqing; Gao, Tianwei; Chen, Fadi; Guan, Zhiyong

2016-01-01

The homeodomain-leucine zipper (HD-Zip) transcription factor family is a key transcription factor family and unique to the plant kingdom. It consists of a homeodomain and a leucine zipper that serve in combination as a dimerization motif. The family can be classified into four subfamilies, and these subfamilies participate in the development of hormones and mediation of hormone action and are involved in plant responses to environmental conditions. However, limited information on this gene family is available for the important chrysanthemum ornamental species (Chrysanthemum morifolium). Here, we characterized 17 chrysanthemum HD-Zip genes based on transcriptome sequences. Phylogenetic analyses revealed that 17 CmHB genes were distributed in the HD-Zip subfamilies I and II and identified two pairs of putative orthologous proteins in Arabidopsis and chrysanthemum and four pairs of paralogous proteins in chrysanthemum. The software MEME was used to identify 7 putative motifs with E values less than 1e-3 in the chrysanthemum HD-Zip factors, and they can be clearly classified into two groups based on the composition of the motifs. A bioinformatics analysis predicted that 8 CmHB genes could be targeted by 10 miRNA families, and the expression of these 17 genes in response to phytohormone treatments and abiotic stresses was characterized. The results presented here will promote research on the various functions of the HD-Zip gene family members in plant hormones and stress responses. PMID:27196930

Suboptimal evolutionary novel environments promote singular altered gravity responses of transcriptome during Drosophila metamorphosis

PubMed Central

2013-01-01

Background Previous experiments have shown that the reduced gravity aboard the International Space Station (ISS) causes important alterations in Drosophila gene expression. These changes were shown to be intimately linked to environmental space-flight related constraints. Results Here, we use an array of different techniques for ground-based simulation of microgravity effects to assess the effect of suboptimal environmental conditions on the gene expression of Drosophila in reduced gravity. A global and integrative analysis, using “gene expression dynamics inspector” (GEDI) self-organizing maps, reveals different degrees in the responses of the transcriptome when using different environmental conditions or microgravity/hypergravity simulation devices. Although the genes that are affected are different in each simulation technique, we find that the same gene ontology groups, including at least one large multigene family related with behavior, stress response or organogenesis, are over represented in each case. Conclusions These results suggest that the transcriptome as a whole can be finely tuned to gravity force. In optimum environmental conditions, the alteration of gravity has only mild effects on gene expression but when environmental conditions are far from optimal, the gene expression must be tuned greatly and effects become more robust, probably linked to the lack of experience of organisms exposed to evolutionary novel environments such as a gravitational free one. PMID:23806134

Transcriptome Analysis in Sheepgrass (Leymus chinensis): A Dominant Perennial Grass of the Eurasian Steppe

PubMed Central

Chen, Shuangyan; Huang, Xin; Yan, Xueqing; Liang, Ye; Wang, Yuezhu; Li, Xiaofeng; Peng, Xianjun; Ma, Xingyong; Zhang, Lexin; Cai, Yueyue; Ma, Tian; Cheng, Liqin; Qi, Dongmei; Zheng, Huajun; Yang, Xiaohan; Li, Xiaoxia; Liu, Gongshe

2013-01-01

Background Sheepgrass [Leymus chinensis (Trin.) Tzvel.] is an important perennial forage grass across the Eurasian Steppe and is known for its adaptability to various environmental conditions. However, insufficient data resources in public databases for sheepgrass limited our understanding of the mechanism of environmental adaptations, gene discovery and molecular marker development. Results The transcriptome of sheepgrass was sequenced using Roche 454 pyrosequencing technology. We assembled 952,328 high-quality reads into 87,214 unigenes, including 32,416 contigs and 54,798 singletons. There were 15,450 contigs over 500 bp in length. BLAST searches of our database against Swiss-Prot and NCBI non-redundant protein sequences (nr) databases resulted in the annotation of 54,584 (62.6%) of the unigenes. Gene Ontology (GO) analysis assigned 89,129 GO term annotations for 17,463 unigenes. We identified 11,675 core Poaceae-specific and 12,811 putative sheepgrass-specific unigenes by BLAST searches against all plant genome and transcriptome databases. A total of 2,979 specific freezing-responsive unigenes were found from this RNAseq dataset. We identified 3,818 EST-SSRs in 3,597 unigenes, and some SSRs contained unigenes that were also candidates for freezing-response genes. Characterizations of nucleotide repeats and dominant motifs of SSRs in sheepgrass were also performed. Similarity and phylogenetic analysis indicated that sheepgrass is closely related to barley and wheat. Conclusions This research has greatly enriched sheepgrass transcriptome resources. The identified stress-related genes will help us to decipher the genetic basis of the environmental and ecological adaptations of this species and will be used to improve wheat and barley crops through hybridization or genetic transformation. The EST-SSRs reported here will be a valuable resource for future gene-phenotype studies and for the molecular breeding of sheepgrass and other Poaceae species. PMID:23861841

Transcriptome analysis in sheepgrass (Leymus chinensis): a dominant perennial grass of the Eurasian Steppe.

PubMed

Chen, Shuangyan; Huang, Xin; Yan, Xueqing; Liang, Ye; Wang, Yuezhu; Li, Xiaofeng; Peng, Xianjun; Ma, Xingyong; Zhang, Lexin; Cai, Yueyue; Ma, Tian; Cheng, Liqin; Qi, Dongmei; Zheng, Huajun; Yang, Xiaohan; Li, Xiaoxia; Liu, Gongshe

2013-01-01

Sheepgrass [Leymus chinensis (Trin.) Tzvel.] is an important perennial forage grass across the Eurasian Steppe and is known for its adaptability to various environmental conditions. However, insufficient data resources in public databases for sheepgrass limited our understanding of the mechanism of environmental adaptations, gene discovery and molecular marker development. The transcriptome of sheepgrass was sequenced using Roche 454 pyrosequencing technology. We assembled 952,328 high-quality reads into 87,214 unigenes, including 32,416 contigs and 54,798 singletons. There were 15,450 contigs over 500 bp in length. BLAST searches of our database against Swiss-Prot and NCBI non-redundant protein sequences (nr) databases resulted in the annotation of 54,584 (62.6%) of the unigenes. Gene Ontology (GO) analysis assigned 89,129 GO term annotations for 17,463 unigenes. We identified 11,675 core Poaceae-specific and 12,811 putative sheepgrass-specific unigenes by BLAST searches against all plant genome and transcriptome databases. A total of 2,979 specific freezing-responsive unigenes were found from this RNAseq dataset. We identified 3,818 EST-SSRs in 3,597 unigenes, and some SSRs contained unigenes that were also candidates for freezing-response genes. Characterizations of nucleotide repeats and dominant motifs of SSRs in sheepgrass were also performed. Similarity and phylogenetic analysis indicated that sheepgrass is closely related to barley and wheat. This research has greatly enriched sheepgrass transcriptome resources. The identified stress-related genes will help us to decipher the genetic basis of the environmental and ecological adaptations of this species and will be used to improve wheat and barley crops through hybridization or genetic transformation. The EST-SSRs reported here will be a valuable resource for future gene-phenotype studies and for the molecular breeding of sheepgrass and other Poaceae species.

Genetic dissection of the Arabidopsis spaceflight transcriptome: Are some responses dispensable for the physiological adaptation of plants to spaceflight?

PubMed Central

Sng, Natasha J.; Zupanska, Agata K.; Krishnamurthy, Aparna; Schultz, Eric R.; Ferl, Robert J.

2017-01-01

Experimentation on the International Space Station has reached the stage where repeated and nuanced transcriptome studies are beginning to illuminate the structural and metabolic differences between plants grown in space compared to plants on the Earth. Genes that are important in establishing the spaceflight responses are being identified, their roles in spaceflight physiological adaptation are increasingly understood, and the fact that different genotypes adapt differently is recognized. However, the basic question of whether these spaceflight responses are actually required for survival has yet to be posed, and the fundamental notion that spaceflight responses may be non-adaptive has yet to be explored. Therefore the experiments presented here were designed to ask if portions of the plant spaceflight response can be genetically removed without causing loss of spaceflight survival and without causing increased stress responses. The CARA experiment compared the spaceflight transcriptome responses in the root tips of two Arabidopsis ecotypes, Col-0 and WS, as well as that of a PhyD mutant of Col-0. When grown with the ambient light of the ISS, phyD plants displayed a significantly reduced spaceflight transcriptome response compared to Col-0, suggesting that altering the activity of a single gene can actually improve spaceflight adaptation by reducing the transcriptome cost of physiological adaptation. The WS genotype showed an even simpler spaceflight transcriptome response in the ambient light of the ISS, more broadly indicating that the plant genotype can be manipulated to reduce the cost of spaceflight adaptation, as measured by transcriptional response. These differential genotypic responses suggest that genetic manipulation could further reduce, or perhaps eliminate the metabolic cost of spaceflight adaptation. When plants were germinated and then left in the dark on the ISS, the WS genotype actually mounted a larger transcriptome response than Col-0, suggesting that the in-space light environment affects physiological adaptation, which implies that manipulating the local habitat can also substantially impact the metabolic cost of spaceflight adaptation. PMID:28662188

Genetic dissection of the Arabidopsis spaceflight transcriptome: Are some responses dispensable for the physiological adaptation of plants to spaceflight?

PubMed

Paul, Anna-Lisa; Sng, Natasha J; Zupanska, Agata K; Krishnamurthy, Aparna; Schultz, Eric R; Ferl, Robert J

2017-01-01

Experimentation on the International Space Station has reached the stage where repeated and nuanced transcriptome studies are beginning to illuminate the structural and metabolic differences between plants grown in space compared to plants on the Earth. Genes that are important in establishing the spaceflight responses are being identified, their roles in spaceflight physiological adaptation are increasingly understood, and the fact that different genotypes adapt differently is recognized. However, the basic question of whether these spaceflight responses are actually required for survival has yet to be posed, and the fundamental notion that spaceflight responses may be non-adaptive has yet to be explored. Therefore the experiments presented here were designed to ask if portions of the plant spaceflight response can be genetically removed without causing loss of spaceflight survival and without causing increased stress responses. The CARA experiment compared the spaceflight transcriptome responses in the root tips of two Arabidopsis ecotypes, Col-0 and WS, as well as that of a PhyD mutant of Col-0. When grown with the ambient light of the ISS, phyD plants displayed a significantly reduced spaceflight transcriptome response compared to Col-0, suggesting that altering the activity of a single gene can actually improve spaceflight adaptation by reducing the transcriptome cost of physiological adaptation. The WS genotype showed an even simpler spaceflight transcriptome response in the ambient light of the ISS, more broadly indicating that the plant genotype can be manipulated to reduce the cost of spaceflight adaptation, as measured by transcriptional response. These differential genotypic responses suggest that genetic manipulation could further reduce, or perhaps eliminate the metabolic cost of spaceflight adaptation. When plants were germinated and then left in the dark on the ISS, the WS genotype actually mounted a larger transcriptome response than Col-0, suggesting that the in-space light environment affects physiological adaptation, which implies that manipulating the local habitat can also substantially impact the metabolic cost of spaceflight adaptation.

Transcriptome Profiling of Chironomus kiinensis under Phenol Stress Using Solexa Sequencing Technology

PubMed Central

Cao, Chuanwang; Wang, Zhiying; Niu, Changying; Desneux, Nicolas; Gao, Xiwu

2013-01-01

Phenol is a major pollutant in aquatic ecosystems due to its chemical stability, water solubility and environmental mobility. To date, little is known about the molecular modifications of invertebrates under phenol stress. In the present study, we used Solexa sequencing technology to investigate the transcriptome and differentially expressed genes (DEGs) of midges (Chironomus kiinensis) in response to phenol stress. A total of 51,518,972 and 51,150,832 clean reads in the phenol-treated and control libraries, respectively, were obtained and assembled into 51,014 non-redundant (Nr) consensus sequences. A total of 6,032 unigenes were classified by Gene Ontology (GO), and 18,366 unigenes were categorized into 238 Kyoto Encyclopedia of Genes and Genomes (KEGG) categories. These genes included representatives from almost all functional categories. A total of 10,724 differentially expressed genes (P value <0.05) were detected in a comparative analysis of the expression profiles between phenol-treated and control C. kiinensis including 8,390 upregulated and 2,334 downregulated genes. The expression levels of 20 differentially expressed genes were confirmed by real-time RT-PCR, and the trends in gene expression that were observed matched the Solexa expression profiles, although the magnitude of the variations was different. Through pathway enrichment analysis, significantly enriched pathways were identified for the DEGs, including metabolic pathways, aryl hydrocarbon receptor (AhR), pancreatic secretion and neuroactive ligand-receptor interaction pathways, which may be associated with the phenol responses of C. kiinensis. Using Solexa sequencing technology, we identified several groups of key candidate genes as well as important biological pathways involved in the molecular modifications of chironomids under phenol stress. PMID:23527048

The impact of oxygen on the transcriptome of recombinant S. cerevisiae and P. pastoris - a comparative analysis.

PubMed

Baumann, Kristin; Dato, Laura; Graf, Alexandra B; Frascotti, Gianni; Dragosits, Martin; Porro, Danilo; Mattanovich, Diethard; Ferrer, Pau; Branduardi, Paola

2011-05-09

Saccharomyces cerevisiae and Pichia pastoris are two of the most relevant microbial eukaryotic platforms for the production of recombinant proteins. Their known genome sequences enabled several transcriptomic profiling studies under many different environmental conditions, thus mimicking not only perturbations and adaptations which occur in their natural surroundings, but also in industrial processes. Notably, the majority of such transcriptome analyses were performed using non-engineered strains.In this comparative study, the gene expression profiles of S. cerevisiae and P. pastoris, a Crabtree positive and Crabtree negative yeast, respectively, were analyzed for three different oxygenation conditions (normoxic, oxygen-limited and hypoxic) under recombinant protein producing conditions in chemostat cultivations. The major differences in the transcriptomes of S. cerevisiae and P. pastoris were observed between hypoxic and normoxic conditions, where the availability of oxygen strongly affected ergosterol biosynthesis, central carbon metabolism and stress responses, particularly the unfolded protein response. Steady state conditions under low oxygen set-points seemed to perturb the transcriptome of S. cerevisiae to a much lesser extent than the one of P. pastoris, reflecting the major tolerance of the baker's yeast towards oxygen limitation, and a higher fermentative capacity. Further important differences were related to Fab production, which was not significantly affected by oxygen availability in S. cerevisiae, while a clear productivity increase had been previously reported for hypoxically grown P. pastoris. The effect of three different levels of oxygen availability on the physiology of P. pastoris and S. cerevisiae revealed a very distinct remodelling of the transcriptional program, leading to novel insights into the different adaptive responses of Crabtree negative and positive yeasts to oxygen availability. Moreover, the application of such comparative genomic studies to recombinant hosts grown in different environments might lead to the identification of key factors for efficient protein production.

Transcriptomic analysis of submergence-tolerant and sensitive Brachypodium distachyon ecotypes reveals oxidative stress as a major tolerance factor

PubMed Central

Rivera-Contreras, Irma Karla; Zamora-Hernández, Teresa; Huerta-Heredia, Ariana Arlene; Capataz-Tafur, Jacqueline; Barrera-Figueroa, Blanca Estela; Juntawong, Piyada; Peña-Castro, Julián Mario

2016-01-01

When excessive amounts of water accumulate around roots and aerial parts of plants, submergence stress occurs. To find the integrated mechanisms of tolerance, we used ecotypes of the monocot model plant Brachypodium distachyon to screen for genetic material with contrasting submergence tolerance. For this purpose, we used a set of previously studied drought sensitive/tolerant ecotypes and the knowledge that drought tolerance is positively associated with submergence stress. We decided to contrast aerial tissue transcriptomes of the ecotype Bd21 14-day-old plants as sensitive and ecotype Bd2-3 as tolerant after 2 days of stress under a long-day photoperiod. Gene ontology and the grouping of transcripts indicated that tolerant Bd2-3 differentially down-regulated NITRATE REDUCTASE and ALTERNATIVE OXIDASE under stress and constitutively up-regulated HAEMOGLOBIN, when compared with the sensitive ecotype, Bd21. These results suggested the removal of nitric oxide, a gaseous phytohormone and concomitant reactive oxygen species as a relevant tolerance determinant. Other mechanisms more active in tolerant Bd2-3 were the pathogen response, glyoxylate and tricarboxylic acid cycle integration, and acetate metabolism. This data set could be employed to design further studies on the basic science of plant tolerance to submergence stress and its biotechnological application in the development of submergence-tolerant crops. PMID:27282694

Jasmonic Acid Enhances Al-Induced Root Growth Inhibition1[OPEN

PubMed Central

Yang, Zhong-Bao; Ma, Yanqi

2017-01-01

Phytohormones such as ethylene and auxin are involved in the regulation of the aluminum (Al)-induced root growth inhibition. Although jasmonate (JA) has been reported to play a crucial role in the regulation of root growth and development in response to environmental stresses through interplay with ethylene and auxin, its role in the regulation of root growth response to Al stress is not yet known. In an attempt to elucidate the role of JA, we found that exogenous application of JA enhanced the Al-induced root growth inhibition. Furthermore, phenotype analysis with mutants defective in either JA biosynthesis or signaling suggests that JA is involved in the regulation of Al-induced root growth inhibition. The expression of the JA receptor CORONATINE INSENSITIVE1 (COI1) and the key JA signaling regulator MYC2 was up-regulated in response to Al stress in the root tips. This process together with COI1-mediated Al-induced root growth inhibition under Al stress was controlled by ethylene but not auxin. Transcriptomic analysis revealed that many responsive genes under Al stress were regulated by JA signaling. The differential responsive of microtubule organization-related genes between the wild-type and coi1-2 mutant is consistent with the changed depolymerization of cortical microtubules in coi1 under Al stress. In addition, ALMT-mediated malate exudation and thus Al exclusion from roots in response to Al stress was also regulated by COI1-mediated JA signaling. Together, this study suggests that root growth inhibition is regulated by COI1-mediated JA signaling independent from auxin signaling and provides novel insights into the phytohormone-mediated root growth inhibition in response to Al stress. PMID:27932419

Jasmonic Acid Enhances Al-Induced Root Growth Inhibition.

PubMed

Yang, Zhong-Bao; He, Chunmei; Ma, Yanqi; Herde, Marco; Ding, Zhaojun

2017-02-01

Phytohormones such as ethylene and auxin are involved in the regulation of the aluminum (Al)-induced root growth inhibition. Although jasmonate (JA) has been reported to play a crucial role in the regulation of root growth and development in response to environmental stresses through interplay with ethylene and auxin, its role in the regulation of root growth response to Al stress is not yet known. In an attempt to elucidate the role of JA, we found that exogenous application of JA enhanced the Al-induced root growth inhibition. Furthermore, phenotype analysis with mutants defective in either JA biosynthesis or signaling suggests that JA is involved in the regulation of Al-induced root growth inhibition. The expression of the JA receptor CORONATINE INSENSITIVE1 (COI1) and the key JA signaling regulator MYC2 was up-regulated in response to Al stress in the root tips. This process together with COI1-mediated Al-induced root growth inhibition under Al stress was controlled by ethylene but not auxin. Transcriptomic analysis revealed that many responsive genes under Al stress were regulated by JA signaling. The differential responsive of microtubule organization-related genes between the wild-type and coi1-2 mutant is consistent with the changed depolymerization of cortical microtubules in coi1 under Al stress. In addition, ALMT-mediated malate exudation and thus Al exclusion from roots in response to Al stress was also regulated by COI1-mediated JA signaling. Together, this study suggests that root growth inhibition is regulated by COI1-mediated JA signaling independent from auxin signaling and provides novel insights into the phytohormone-mediated root growth inhibition in response to Al stress. © 2017 American Society of Plant Biologists. All Rights Reserved.

Transcriptome, expression, and activity analyses reveal a vital heat shock protein 70 in the stress response of stony coral Pocillopora damicornis.

PubMed

Zhang, Yidan; Zhou, Zhi; Wang, Lingui; Huang, Bo

2018-02-12

Coral bleaching occurs worldwide with increasing frequencies and intensities, which is caused by the stress response of stony coral to environmental change, especially increased sea surface temperature. In the present study, transcriptome, expression, and activity analyses were employed to illustrate the underlying molecular mechanisms of heat shock protein 70 (HSP70) in the stress response of coral to environmental changes. The domain analyses of assembled transcripts revealed 30 HSP70 gene contigs in stony coral Pocillopora damicornis. One crucial HSP70 (PdHSP70) was observed, whose expressions were induced by both elevated temperature and ammonium after expression difference analysis. The complete complementary DNA (cDNA) sequence of PdHSP70 was identified, which encoded a polypeptide of 650 amino acids with a molecular weight of 71.93 kDa. The deduced amino acid sequence of PdHSP70 contained a HSP70 domain (from Pro8 to Gly616), and it shared the highest similarity (95%) with HSP70 from Stylophora pistillata. The expression level of PdHSP70 gene increased significantly at 12 h, and returned to the initial level at 24 h after the stress of high temperature (32 °C). The cDNA fragment encoding the mature peptide of PdHSP70 was recombined and expressed in the prokaryotic expression system. The ATPase activity of recombinant PdHSP70 protein was determined, and it did not change significantly in a wide range of temperature from 25 to 40 °C. These results collectively suggested that PdHSP70 was a vital heat shock protein 70 in the stony coral P. damicornis, whose mRNA expression could be induced by diverse environmental stress and whose activity could remain stable under heat stress. PdHSP70 might be involved in the regulation of the bleaching owing to heat stress in the stony coral P. damicornis.

Transcriptional changes of rice in response to rice black-streaked dwarf virus.

PubMed

Ahmed, Mohamed M S; Ji, Wen; Wang, Muyue; Bian, Shiquan; Xu, Meng; Wang, Weiyun; Zhang, Jiangxiang; Xu, Zhihao; Yu, Meimei; Liu, Qiaoquan; Zhang, Changquan; Zhang, Honggen; Tang, Shuzhu; Gu, Minghong; Yu, Hengxiu

2017-09-10

Rice black-streaked dwarf virus (RBSDV), a member of the genus Fijivirus in the family Reoviridae, causes significant economic losses in rice production in China and many other Asian countries. Although a great deal of effort has been made to elucidate the interactions among the virus, insect vectors, host and environmental conditions, few RBSDV proteins involved in pathogenesis have been identified, and the biological basis of disease development in rice remains largely unknown. Transcriptomic information associated with the disease development in rice would be helpful to unravel the biological mechanism. To determine how the rice transcriptome changes in response to RBSDV infection, we carried out RNA-Seq to perform a genome-wide gene expression analysis of a susceptible rice cultivar KTWYJ3. The transcriptomes of RBSDV-infected samples were compared to those of RBSDV-free (healthy) at two time points (time points are represented by group I and II). The results derived from the differential expression analysis in RBSDV-infected libraries vs. healthy ones in group I revealed that 102 out of a total of 281 significant differentially expressed genes (DEGs) were up-regulated and 179 DEGs were down-regulated. Of the 2592 identified DEGs in group II, 1588 DEGs were up-regulated and 1004 DEGs were down-regulated. A total of 66 DEGs were commonly identified in both groups. Of these 66 DEGs, expression patterns for 36 DEGs were similar in both groups. Our analysis demonstrated that some genes related to disease defense and stress resistance were up-regulated while genes associated with chloroplast were down-regulated in response to RBSDV infection. In addition, some genes associated with plant-height were differentially expressed. This result indicates those genes might be involved in dwarf symptoms caused by RBSDV. Taken together, our results provide a genome-wide transcriptome analysis for rice plants in response to RBSDV infection which may contribute to the understanding of the regulatory mechanisms involved in rice-RBSDV interaction and the biological basis of rice black-streaked dwarf disease development in rice. Copyright © 2017 Elsevier B.V. All rights reserved.

Identification and Expression Profiling of the Auxin Response Factors in Dendrobium officinale under Abiotic Stresses

PubMed Central

Chen, Zhehao; Yuan, Ye; Fu, Di; Shen, Chenjia; Yang, Yanjun

2017-01-01

Auxin response factor (ARF) proteins play roles in plant responses to diverse environmental stresses by binding specifically to the auxin response element in the promoters of target genes. Using our latest public Dendrobium transcriptomes, a comprehensive characterization and analysis of 14 DnARF genes were performed. Three selected DnARFs, including DnARF1, DnARF4, and DnARF6, were confirmed to be nuclear proteins according to their transient expression in epidermal cells of Nicotiana benthamiana leaves. Furthermore, the transcription activation abilities of DnARF1, DnARF4, and DnARF6 were tested in a yeast system. Our data showed that DnARF6 is a transcriptional activator in Dendrobium officinale. To uncover the basic information of DnARF gene responses to abiotic stresses, we analyzed their expression patterns under various hormones and abiotic treatments. Based on our data, several hormones and significant stress responsive DnARF genes have been identified. Since auxin and ARF genes have been identified in many plant species, our data is imperative to reveal the function of ARF mediated auxin signaling in the adaptation to the challenging Dendrobium environment. PMID:28471373

Identification and Expression Profiling of the Auxin Response Factors in Dendrobium officinale under Abiotic Stresses.

PubMed

Chen, Zhehao; Yuan, Ye; Fu, Di; Shen, Chenjia; Yang, Yanjun

2017-05-04

Auxin response factor (ARF) proteins play roles in plant responses to diverse environmental stresses by binding specifically to the auxin response element in the promoters of target genes. Using our latest public Dendrobium transcriptomes, a comprehensive characterization and analysis of 14 DnARF genes were performed. Three selected DnARFs , including DnARF1 , DnARF4 , and DnARF6 , were confirmed to be nuclear proteins according to their transient expression in epidermal cells of Nicotiana benthamiana leaves. Furthermore, the transcription activation abilities of DnARF1 , DnARF4 , and DnARF6 were tested in a yeast system. Our data showed that DnARF6 is a transcriptional activator in Dendrobium officinale . To uncover the basic information of DnARF gene responses to abiotic stresses, we analyzed their expression patterns under various hormones and abiotic treatments. Based on our data, several hormones and significant stress responsive DnARF genes have been identified. Since auxin and ARF genes have been identified in many plant species, our data is imperative to reveal the function of ARF mediated auxin signaling in the adaptation to the challenging Dendrobium environment.

Analysis of essential gene dynamics under antibiotic stress in Streptococcus sanguinis

PubMed Central

El-Rami, Fadi; Kong, Xiangzhen; Parikh, Hardik; Zhu, Bin; Stone, Victoria; Kitten, Todd; Xu, Ping

2018-01-01

The paradoxical response of Streptococcus sanguinis to drugs prescribed for dental and clinical practices has complicated treatment guidelines and raised the need for further investigation. We conducted a high throughput study on concomitant transcriptome and proteome dynamics in a time course to assess S. sanguinis behaviour under a sub-inhibitory concentration of ampicillin. Temporal changes at the transcriptome and proteome level were monitored to cover essential genes and proteins over a physiological map of intricate pathways. Our findings revealed that translation was the functional category in S. sanguinis that was most enriched in essential proteins. Moreover, essential proteins in this category demonstrated the greatest conservation across 2774 bacterial proteomes, in comparison to other essential functional categories like cell wall biosynthesis and energy production. In comparison to non-essential proteins, essential proteins were less likely to contain ‘degradation-prone’ amino acids at their N-terminal position, suggesting a longer half-life. Despite the ampicillin-induced stress, the transcriptional up-regulation of amino acid-tRNA synthetases and proteomic elevation of amino acid biosynthesis enzymes favoured the enriched components of essential proteins revealing ‘proteomic signatures’ that can be used to bridge the genotype–phenotype gap of S. sanguinis under ampicillin stress. Furthermore, we identified a significant correlation between the levels of mRNA and protein for essential genes and detected essential protein-enriched pathways differentially regulated through a persistent stress response pattern at late time points. We propose that the current findings will help characterize a bacterial model to study the dynamics of essential genes and proteins under clinically relevant stress conditions. PMID:29393020

Transcriptional profiling of Medicago truncatula under salt stress identified a novel CBF transcription factor MtCBF4 that plays an important role in abiotic stress responses

PubMed Central

2011-01-01

Background Salt stress hinders the growth of plants and reduces crop production worldwide. However, different plant species might possess different adaptive mechanisms to mitigate salt stress. We conducted a detailed pathway analysis of transcriptional dynamics in the roots of Medicago truncatula seedlings under salt stress and selected a transcription factor gene, MtCBF4, for experimental validation. Results A microarray experiment was conducted using root samples collected 6, 24, and 48 h after application of 180 mM NaCl. Analysis of 11 statistically significant expression profiles revealed different behaviors between primary and secondary metabolism pathways in response to external stress. Secondary metabolism that helps to maintain osmotic balance was induced. One of the highly induced transcription factor genes was successfully cloned, and was named MtCBF4. Phylogenetic analysis revealed that MtCBF4, which belongs to the AP2-EREBP transcription factor family, is a novel member of the CBF transcription factor in M. truncatula. MtCBF4 is shown to be a nuclear-localized protein. Expression of MtCBF4 in M. truncatula was induced by most of the abiotic stresses, including salt, drought, cold, and abscisic acid, suggesting crosstalk between these abiotic stresses. Transgenic Arabidopsis over-expressing MtCBF4 enhanced tolerance to drought and salt stress, and activated expression of downstream genes that contain DRE elements. Over-expression of MtCBF4 in M. truncatula also enhanced salt tolerance and induced expression level of corresponding downstream genes. Conclusion Comprehensive transcriptomic analysis revealed complex mechanisms exist in plants in response to salt stress. The novel transcription factor gene MtCBF4 identified here played an important role in response to abiotic stresses, indicating that it might be a good candidate gene for genetic improvement to produce stress-tolerant plants. PMID:21718548

Genome and Transcriptome Analyses Provide Insight into the Euryhaline Adaptation Mechanism of Crassostrea gigas

PubMed Central

Zhang, Linlin; Li, Chunyan; Li, Li; She, Zhicai; Huang, Baoyu; Zhang, Guofan

2013-01-01

Background The Pacific oyster, Crassostrea gigas, has developed special mechanisms to regulate its osmotic balance to adapt to fluctuations of salinities in coastal zones. To understand the oyster’s euryhaline adaptation, we analyzed salt stress effectors metabolism pathways under different salinities (salt 5, 10, 15, 20, 25, 30 and 40 for 7 days) using transcriptome data, physiology experiment and quantitative real-time PCR. Results Transcriptome data uncovered 189, 480, 207 and 80 marker genes for monitoring physiology status of oysters and the environment conditions. Three known salt stress effectors (involving ion channels, aquaporins and free amino acids) were examined. The analysis of ion channels and aquaporins indicated that 7 days long-term salt stress inhibited voltage-gated Na+/K+ channel and aquaporin but increased calcium-activated K+ channel and Ca2+ channel. As the most important category of osmotic stress effector, we analyzed the oyster FAAs metabolism pathways (including taurine, glycine, alanine, beta-alanine, proline and arginine) and explained FAAs functional mechanism for oyster low salinity adaptation. FAAs metabolism key enzyme genes displayed expression differentiation in low salinity adapted individuals comparing with control which further indicated that FAAs played important roles for oyster salinity adaptation. A global metabolic pathway analysis (iPath) of oyster expanded genes displayed a co-expansion of FAAs metabolism in C. gigas compared with seven other species, suggesting oyster’s powerful ability regarding FAAs metabolism, allowing it to adapt to fluctuating salinities, which may be one important mechanism underlying euryhaline adaption in oyster. Additionally, using transcriptome data analysis, we uncovered salt stress transduction networks in C. gigas. Conclusions Our results represented oyster salt stress effectors functional mechanisms under salt stress conditions and explained the expansion of FAAs metabolism pathways as the most important effectors for oyster euryhaline adaptation. This study was the first to explain oyster euryhaline adaptation at a genome-wide scale in C. gigas. PMID:23554902

Daytime soybean transcriptome fluctuations during water deficit stress

USDA-ARS?s Scientific Manuscript database

Since drought can seriously affect plant growth and development and little is known about how the oscillations of gene expression during the drought stress-acclimation response in soybean is affected, we applied Illumina technology to sequence 36 cDNA libraries synthesized from control and drought-s...

Comparative transcriptomics involving greenbug and water-deficit stress responses in hard-red winter wheat

USDA-ARS?s Scientific Manuscript database

Sessile nature of plants necessitates them to perceive impending cues about biotic and abiotic stresses and alter their growth accordingly by eliciting appropriate defense signals. During the evolutionary progression, plants have developed sophisticated mechanisms to precisely identify the nature of...

Rapid stress-induced transcriptomic changes in the brain depend on beta-adrenergic signaling.

PubMed

Roszkowski, Martin; Manuella, Francesca; von Ziegler, Lukas; Durán-Pacheco, Gonzalo; Moreau, Jean-Luc; Mansuy, Isabelle M; Bohacek, Johannes

2016-08-01

Acute exposure to stressful experiences can rapidly increase anxiety and cause neuropsychiatric disorders. The effects of stress result in part from the release of neurotransmitters and hormones, which regulate gene expression in different brain regions. The fast neuroendocrine response to stress is largely mediated by norepinephrine (NE) and corticotropin releasing hormone (CRH), followed by a slower and more sustained release of corticosterone. While corticosterone is an important regulator of gene expression, it is not clear which stress-signals contribute to the rapid regulation of gene expression observed immediately after stress exposure. Here, we demonstrate in mice that 45 min after an acute swim stress challenge, large changes in gene expression occur across the transcriptome in the hippocampus, a region sensitive to the effects of stress. We identify multiple candidate genes that are rapidly and transiently altered in both males and females. Using a pharmacological approach, we show that most of these rapidly induced genes are regulated by NE through β-adrenergic receptor signaling. We find that CRH and corticosterone can also contribute to rapid changes in gene expression, although these effects appear to be restricted to fewer genes. These results newly reveal a widespread impact of NE on the transcriptome and identify novel genes associated with stress and adrenergic signaling. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparative transcriptome analysis reveals insights into the streamlined genomes of haplosclerid demosponges

PubMed Central

Guzman, Christine; Conaco, Cecilia

2016-01-01

Sponges (Porifera) are one of the most ancestral metazoan groups. They are characterized by a simple body plan lacking the true tissues and organ systems found in other animals. Members of this phylum display a remarkable diversity of form and function and yet little is known about the composition and complexity of their genomes. In this study, we sequenced the transcriptomes of two marine haplosclerid sponges belonging to Demospongiae, the largest and most diverse class within phylum Porifera, and compared their gene content with members of other sponge classes. We recovered 44,693 and 50,067 transcripts expressed in adult tissues of Haliclona amboinensis and Haliclona tubifera, respectively. These transcripts translate into 20,280 peptides in H. amboinensis and 18,000 peptides in H. tubifera. Genes associated with important signaling and metabolic pathways, regulatory networks, as well as genes that may be important in the organismal stress response, were identified in the transcriptomes. Futhermore, lineage-specific innovations were identified that may be correlated with observed sponge characters and ecological adaptations. The core gene complement expressed within the tissues of adult haplosclerid demosponges may represent a streamlined and flexible genetic toolkit that underlies the ecological success and resilience of sponges to environmental stress. PMID:26738846

Transcriptome analysis of Cronobacter sakazakii ATCC BAA-894 after interaction with human intestinal epithelial cell line HCT-8.

PubMed

Jing, Chun-e; Du, Xin-jun; Li, Ping; Wang, Shuo

2016-01-01

Cronobacter spp. are opportunistic pathogens that are responsible for infections including severe meningitis, septicemia, and necrotizing enterocolitis in neonates and infants. To date, questions still remain regarding the mechanisms of pathogenicity and virulence determinants for each bacterial strain. In this study, we established an in vitro model for Cronobacter sakazakii ATCC BAA-894 infection of HCT-8 human colorectal epithelial cells. The transcriptome profile of C. sakazakii ATCC BAA-894 after interaction with HCT-8 cells was determined using high-throughput whole-transcriptome sequencing (RNA sequencing (RNA-seq)). Gene expression profiles indicated that 139 genes were upregulated and 72 genes were downregulated in the adherent C. sakazakii ATCC BAA-894 strain on HCT-8 cells compared to the cultured bacteria in the cell-free medium. Expressions of some flagella genes and virulence factors involved in adherence were upregulated. High osmolarity and osmotic stress-associated genes were highly upregulated, as well as genes responsible for the synthesis of lipopolysaccharides and outer membrane proteins, iron acquisition systems, and glycerol and glycerophospholipid metabolism. In sum, our study provides further insight into the mechanisms underlying C. sakazakii pathogenesis in the human gastrointestinal tract.

RNA-Seq analysis of salinity stress-responsive transcriptome in the liver of spotted sea bass (Lateolabrax maculatus).

PubMed

Zhang, Xiaoyan; Wen, Haishen; Wang, Hailiang; Ren, Yuanyuan; Zhao, Ji; Li, Yun

2017-01-01

Salinity is one of the most prominent abiotic factors, which greatly influence reproduction, development, growth, physiological and metabolic activities of fishes. Spotted sea bass (Lateolabrax maculatus), as a euryhaline marine teleost, has extraordinary ability to deal with a wide range of salinity changes. However, this species is devoid of genomic resources, and no study has been conducted at the transcriptomic level to determine genes responsible for salinity regulation, which impedes the understanding of the fundamental mechanism conferring tolerance to salinity fluctuations. Liver, as the major metabolic organ, is the key source supplying energy for iono- and osmoregulation in fish, however, little attention has been paid to its salinity-related functions but which should not be ignored. In this study, we perform RNA-Seq analysis to identify genes involved in salinity adaptation and osmoregulation in liver of spotted sea bass, generating from the fishes exposed to low and high salinity water (5 vs 30ppt). After de novo assembly, annotation and differential gene expression analysis, a total of 455 genes were differentially expressed, including 184 up-regulated and 271 down-regulated transcripts in low salinity-acclimated fish group compared with that in high salinity-acclimated group. A number of genes with a potential role in salinity adaptation for spotted sea bass were classified into five functional categories based on the gene ontology (GO) and enrichment analysis, which include genes involved in metabolites and ion transporters, energy metabolism, signal transduction, immune response and structure reorganization. The candidate genes identified in L. maculates liver provide valuable information to explore new pathways related to fish salinity and osmotic regulation. Besides, the transcriptomic sequencing data supplies significant resources for identification of novel genes and further studying biological questions in spotted sea bass.

From root to fruit: RNA-Seq analysis shows that arbuscular mycorrhizal symbiosis may affect tomato fruit metabolism.

PubMed

Zouari, Inès; Salvioli, Alessandra; Chialva, Matteo; Novero, Mara; Miozzi, Laura; Tenore, Gian Carlo; Bagnaresi, Paolo; Bonfante, Paola

2014-03-21

Tomato (Solanum lycopersicum) establishes a beneficial symbiosis with arbuscular mycorrhizal (AM) fungi. The formation of the mycorrhizal association in the roots leads to plant-wide modulation of gene expression. To understand the systemic effect of the fungal symbiosis on the tomato fruit, we used RNA-Seq to perform global transcriptome profiling on Moneymaker tomato fruits at the turning ripening stage. Fruits were collected at 55 days after flowering, from plants colonized with Funneliformis mosseae and from control plants, which were fertilized to avoid responses related to nutrient deficiency. Transcriptome analysis identified 712 genes that are differentially expressed in fruits from mycorrhizal and control plants. Gene Ontology (GO) enrichment analysis of these genes showed 81 overrepresented functional GO classes. Up-regulated GO classes include photosynthesis, stress response, transport, amino acid synthesis and carbohydrate metabolism functions, suggesting a general impact of fungal symbiosis on primary metabolisms and, particularly, on mineral nutrition. Down-regulated GO classes include cell wall, metabolism and ethylene response pathways. Quantitative RT-PCR validated the RNA-Seq results for 12 genes out of 14 when tested at three fruit ripening stages, mature green, breaker and turning. Quantification of fruit nutraceutical and mineral contents produced values consistent with the expression changes observed by RNA-Seq analysis. This RNA-Seq profiling produced a novel data set that explores the intersection of mycorrhization and fruit development. We found that the fruits of mycorrhizal plants show two transcriptomic "signatures": genes characteristic of a climacteric fleshy fruit, and genes characteristic of mycorrhizal status, like phosphate and sulphate transporters. Moreover, mycorrhizal plants under low nutrient conditions produce fruits with a nutrient content similar to those from non-mycorrhizal plants under high nutrient conditions, indicating that AM fungi can help replace exogenous fertilizer for fruit crops.

The dehydration stress of couch grass is associated with its lipid metabolism, the induction of transporters and the re-programming of development coordinated by ABA.

PubMed

Janská, Anna; Svoboda, Pavel; Spiwok, Vojtěch; Kučera, Ladislav; Ovesná, Jaroslava

2018-05-02

The wild relatives of crop species represent a potentially valuable source of novel genetic variation, particularly in the context of improving the crop's level of tolerance to abiotic stress. The mechanistic basis of these tolerances remains largely unexplored. Here, the focus was to characterize the transcriptomic response of the nodes (meristematic tissue) of couch grass (a relative of barley) to dehydration stress, and to compare it to that of the barley crown formed by both a drought tolerant and a drought sensitive barley cultivar. Many of the genes up-regulated in the nodes by the stress were homologs of genes known to be mediated by abscisic acid during the response to drought, or were linked to either development or lipid metabolism. Transporters also featured prominently, as did genes acting on root architecture. The resilience of the couch grass node arise from both their capacity to develop an altered, more effective root architecture, but also from their formation of a lipid barrier on their outer surface and their ability to modify both their lipid metabolism and transporter activity when challenged by dehydration stress. Our analysis revealed the nature of dehydration stress response in couch grass. We suggested the tolerance is associated with lipid metabolism, the induction of transporters and the re-programming of development coordinated by ABA. We also proved the applicability of barley microarray for couch grass stress-response analysis.

The aquatic animals' transcriptome resource for comparative functional analysis.

PubMed

Chou, Chih-Hung; Huang, Hsi-Yuan; Huang, Wei-Chih; Hsu, Sheng-Da; Hsiao, Chung-Der; Liu, Chia-Yu; Chen, Yu-Hung; Liu, Yu-Chen; Huang, Wei-Yun; Lee, Meng-Lin; Chen, Yi-Chang; Huang, Hsien-Da

2018-05-09

Aquatic animals have great economic and ecological importance. Among them, non-model organisms have been studied regarding eco-toxicity, stress biology, and environmental adaptation. Due to recent advances in next-generation sequencing techniques, large amounts of RNA-seq data for aquatic animals are publicly available. However, currently there is no comprehensive resource exist for the analysis, unification, and integration of these datasets. This study utilizes computational approaches to build a new resource of transcriptomic maps for aquatic animals. This aquatic animal transcriptome map database dbATM provides de novo assembly of transcriptome, gene annotation and comparative analysis of more than twenty aquatic organisms without draft genome. To improve the assembly quality, three computational tools (Trinity, Oases and SOAPdenovo-Trans) were employed to enhance individual transcriptome assembly, and CAP3 and CD-HIT-EST software were then used to merge these three assembled transcriptomes. In addition, functional annotation analysis provides valuable clues to gene characteristics, including full-length transcript coding regions, conserved domains, gene ontology and KEGG pathways. Furthermore, all aquatic animal genes are essential for comparative genomics tasks such as constructing homologous gene groups and blast databases and phylogenetic analysis. In conclusion, we establish a resource for non model organism aquatic animals, which is great economic and ecological importance and provide transcriptomic information including functional annotation and comparative transcriptome analysis. The database is now publically accessible through the URL http://dbATM.mbc.nctu.edu.tw/ .

Next-Generation Transcriptome Profiling of the Salmon Louse Caligus rogercresseyi Exposed to Deltamethrin (AlphaMax™): Discovery of Relevant Genes and Sex-Related Differences.

PubMed

Chávez-Mardones, Jacqueline; Gallardo-Escárate, Cristian

2015-12-01

Sea lice are one of the main parasites affecting the salmon aquaculture industry, causing significant economic losses worldwide. Increased resistance to traditional chemical treatments has created the need to find alternative control methods. Therefore, the objective of this study was to identify the transcriptome response of the salmon louse Caligus rogercresseyi to the delousing drug deltamethrin (AlphaMax™). Through bioassays with different concentrations of deltamethrin, adult salmon lice transcriptomes were sequenced from cDNA libraries in the MiSeq Illumina platform. A total of 78 million reads for females and males were assembled in 30,212 and 38,536 contigs, respectively. De novo assembly yielded 86,878 high-quality contigs and, based on published data, it was possible to annotate and identify relevant genes involved in several biological processes. RNA-seq analysis in conjunction with heatmap hierarchical clustering evidenced that pyrethroids modify the ectoparasitic transcriptome in adults, affecting molecular processes associated with the nervous system, cuticle formation, oxidative stress, reproduction, and metabolism, among others. Furthermore, sex-related transcriptome differences were evidenced. Specifically, 534 and 1033 exclusive transcripts were identified for males and females, respectively, and 154 were shared between sexes. For males, estradiol 17-beta-dehydrogenase, sphingolipid delta4-desaturase DES1, ketosamine-3-kinase, and arylsulfatase A, among others, were discovered, while for females, vitellogenin 1, glycoprotein G, transaldolase, and nitric oxide synthase were among those identified. The shared transcripts included annotations for tropomyosin, γ-crystallin A, glutamate receptor-metabotropic, glutathione S-transferase, and carboxipeptidase B. The present study reveals that deltamethrin generates a complex transcriptome response in C. rogercresseyi, thus providing valuable genomic information for developing new delousing drugs.

Rice-arsenate interactions in hydroponics: whole genome transcriptional analysis.

PubMed

Norton, Gareth J; Lou-Hing, Daniel E; Meharg, Andrew A; Price, Adam H

2008-01-01

Rice (Oryza sativa) varieties that are arsenate-tolerant (Bala) and -sensitive (Azucena) were used to conduct a transcriptome analysis of the response of rice seedlings to sodium arsenate (AsV) in hydroponic solution. RNA extracted from the roots of three replicate experiments of plants grown for 1 week in phosphate-free nutrient with or without 13.3 muM AsV was used to challenge the Affymetrix (52K) GeneChip Rice Genome array. A total of 576 probe sets were significantly up-regulated at least 2-fold in both varieties, whereas 622 were down-regulated. Ontological classification is presented. As expected, a large number of transcription factors, stress proteins, and transporters demonstrated differential expression. Striking is the lack of response of classic oxidative stress-responsive genes or phytochelatin synthases/synthatases. However, the large number of responses from genes involved in glutathione synthesis, metabolism, and transport suggests that glutathione conjugation and arsenate methylation may be important biochemical responses to arsenate challenge. In this report, no attempt is made to dissect differences in the response of the tolerant and sensitive variety, but analysis in a companion article will link gene expression to the known tolerance loci available in the BalaxAzucena mapping population.

Rice–arsenate interactions in hydroponics: whole genome transcriptional analysis

PubMed Central

Norton, Gareth J.; Lou-Hing, Daniel E.; Meharg, Andrew A.; Price, Adam H.

2008-01-01

Rice (Oryza sativa) varieties that are arsenate-tolerant (Bala) and -sensitive (Azucena) were used to conduct a transcriptome analysis of the response of rice seedlings to sodium arsenate (AsV) in hydroponic solution. RNA extracted from the roots of three replicate experiments of plants grown for 1 week in phosphate-free nutrient with or without 13.3 μM AsV was used to challenge the Affymetrix (52K) GeneChip Rice Genome array. A total of 576 probe sets were significantly up-regulated at least 2-fold in both varieties, whereas 622 were down-regulated. Ontological classification is presented. As expected, a large number of transcription factors, stress proteins, and transporters demonstrated differential expression. Striking is the lack of response of classic oxidative stress-responsive genes or phytochelatin synthases/synthatases. However, the large number of responses from genes involved in glutathione synthesis, metabolism, and transport suggests that glutathione conjugation and arsenate methylation may be important biochemical responses to arsenate challenge. In this report, no attempt is made to dissect differences in the response of the tolerant and sensitive variety, but analysis in a companion article will link gene expression to the known tolerance loci available in the Bala×Azucena mapping population. PMID:18453530

De novo transcriptome profiling of cold-stressed siliques during pod filling stages in Indian mustard (Brassica juncea L.)

PubMed Central

Sinha, Somya; Raxwal, Vivek K.; Joshi, Bharat; Jagannath, Arun; Katiyar-Agarwal, Surekha; Goel, Shailendra; Kumar, Amar; Agarwal, Manu

2015-01-01

Low temperature is a major abiotic stress that impedes plant growth and development. Brassica juncea is an economically important oil seed crop and is sensitive to freezing stress during pod filling subsequently leading to abortion of seeds. To understand the cold stress mediated global perturbations in gene expression, whole transcriptome of B. juncea siliques that were exposed to sub-optimal temperature was sequenced. Manually self-pollinated siliques at different stages of development were subjected to either short (6 h) or long (12 h) durations of chilling stress followed by construction of RNA-seq libraries and deep sequencing using Illumina's NGS platform. De-novo assembly of B. juncea transcriptome resulted in 133,641 transcripts, whose combined length was 117 Mb and N50 value was 1428 bp. We identified 13,342 differentially regulated transcripts by pair-wise comparison of 18 transcriptome libraries. Hierarchical clustering along with Spearman correlation analysis identified that the differentially expressed genes segregated in two major clusters representing early (5–15 DAP) and late stages (20–30 DAP) of silique development. Further analysis led to the discovery of sub-clusters having similar patterns of gene expression. Two of the sub-clusters (one each from the early and late stages) comprised of genes that were inducible by both the durations of cold stress. Comparison of transcripts from these clusters led to identification of 283 transcripts that were commonly induced by cold stress, and were referred to as “core cold-inducible” transcripts. Additionally, we found that 689 and 100 transcripts were specifically up-regulated by cold stress in early and late stages, respectively. We further explored the expression patterns of gene families encoding for transcription factors (TFs), transcription regulators (TRs) and kinases, and found that cold stress induced protein kinases only during early silique development. We validated the digital gene expression profiles of selected transcripts by qPCR and found a high degree of concordance between the two analyses. To our knowledge this is the first report of transcriptome sequencing of cold-stressed B. juncea siliques. The data generated in this study would be a valuable resource for not only understanding the cold stress signaling pathway but also for introducing cold hardiness in B. juncea. PMID:26579175

ALOMYbase, a resource to investigate non-target-site-based resistance to herbicides inhibiting acetolactate-synthase (ALS) in the major grass weed Alopecurus myosuroides (black-grass).

PubMed

Gardin, Jeanne Aude Christiane; Gouzy, Jérôme; Carrère, Sébastien; Délye, Christophe

2015-08-12

Herbicide resistance in agrestal weeds is a global problem threatening food security. Non-target-site resistance (NTSR) endowed by mechanisms neutralising the herbicide or compensating for its action is considered the most agronomically noxious type of resistance. Contrary to target-site resistance, NTSR mechanisms are far from being fully elucidated. A part of weed response to herbicide stress, NTSR is considered to be largely driven by gene regulation. Our purpose was to establish a transcriptome resource allowing investigation of the transcriptomic bases of NTSR in the major grass weed Alopecurus myosuroides L. (Poaceae) for which almost no genomic or transcriptomic data was available. RNA-Seq was performed from plants in one F2 population that were sensitive or expressing NTSR to herbicides inhibiting acetolactate-synthase. Cloned plants were sampled over seven time-points ranging from before until 73 h after herbicide application. Assembly of over 159M high-quality Illumina reads generated a transcriptomic resource (ALOMYbase) containing 65,558 potentially active contigs (N50 = 1240 nucleotides) predicted to encode 32,138 peptides with 74% GO annotation, of which 2017 were assigned to protein families presumably involved in NTSR. Comparison with the fully sequenced grass genomes indicated good coverage and correct representation of A. myosuroides transcriptome in ALOMYbase. The part of the herbicide transcriptomic response common to the resistant and the sensitive plants was consistent with the expected effects of acetolactate-synthase inhibition, with striking similarities observed with published Arabidopsis thaliana data. A. myosuroides plants with NTSR were first affected by herbicide action like sensitive plants, but ultimately overcame it. Analysis of differences in transcriptomic herbicide response between resistant and sensitive plants did not allow identification of processes directly explaining NTSR. Five contigs associated to NTSR in the F2 population studied were tentatively identified. They were predicted to encode three cytochromes P450 (CYP71A, CYP71B and CYP81D), one peroxidase and one disease resistance protein. Our data confirmed that gene regulation is at the root of herbicide response and of NTSR. ALOMYbase proved to be a relevant resource to support NTSR transcriptomic studies, and constitutes a valuable tool for future research aiming at elucidating gene regulations involved in NTSR in A. myosuroides.

Analysis of drought-responsive signalling network in two contrasting rice cultivars using transcriptome-based approach

PubMed Central

Borah, Pratikshya; Sharma, Eshan; Kaur, Amarjot; Chandel, Girish; Mohapatra, Trilochan; Kapoor, Sanjay; Khurana, Jitendra P.

2017-01-01

Traditional cultivars of rice in India exhibit tolerance to drought stress due to their inherent genetic variations. Here we present comparative physiological and transcriptome analyses of two contrasting cultivars, drought tolerant Dhagaddeshi (DD) and susceptible IR20. Microarray analysis revealed several differentially expressed genes (DEGs) exclusively in DD as compared to IR20 seedlings exposed to 3 h drought stress. Physiologically, DD seedlings showed higher cell membrane stability and differential ABA accumulation in response to dehydration, coupled with rapid changes in gene expression. Detailed analyses of metabolic pathways enriched in expression data suggest interplay of ABA dependent along with secondary and redox metabolic networks that activate osmotic and detoxification signalling in DD. By co-localization of DEGs with QTLs from databases or published literature for physiological traits of DD and IR20, candidate genes were identified including those underlying major QTL qDTY1.1 in DD. Further, we identified previously uncharacterized genes from both DD and IR20 under drought conditions including OsWRKY51, OsVP1 and confirmed their expression by qPCR in multiple rice cultivars. OsFBK1 was also functionally validated in susceptible PB1 rice cultivar and Arabidopsis for providing drought tolerance. Some of the DEGs mapped to the known QTLs could thus, be of potential significance for marker-assisted breeding. PMID:28181537

Research Resource: A Reference Transcriptome for Constitutive Androstane Receptor and Pregnane X Receptor Xenobiotic Signaling

PubMed Central

Ochsner, Scott A.; Tsimelzon, Anna; Dong, Jianrong; Coarfa, Cristian

2016-01-01

The pregnane X receptor (PXR) (PXR/NR1I3) and constitutive androstane receptor (CAR) (CAR/NR1I2) members of the nuclear receptor (NR) superfamily of ligand-regulated transcription factors are well-characterized mediators of xenobiotic and endocrine-disrupting chemical signaling. The Nuclear Receptor Signaling Atlas maintains a growing library of transcriptomic datasets involving perturbations of NR signaling pathways, many of which involve perturbations relevant to PXR and CAR xenobiotic signaling. Here, we generated a reference transcriptome based on the frequency of differential expression of genes across 159 experiments compiled from 22 datasets involving perturbations of CAR and PXR signaling pathways. In addition to the anticipated overrepresentation in the reference transcriptome of genes encoding components of the xenobiotic stress response, the ranking of genes involved in carbohydrate metabolism and gonadotropin action sheds mechanistic light on the suspected role of xenobiotics in metabolic syndrome and reproductive disorders. Gene Set Enrichment Analysis showed that although acetaminophen, chlorpromazine, and phenobarbital impacted many similar gene sets, differences in direction of regulation were evident in a variety of processes. Strikingly, gene sets representing genes linked to Parkinson's, Huntington's, and Alzheimer's diseases were enriched in all 3 transcriptomes. The reference xenobiotic transcriptome will be supplemented with additional future datasets to provide the community with a continually updated reference transcriptomic dataset for CAR- and PXR-mediated xenobiotic signaling. Our study demonstrates how aggregating and annotating transcriptomic datasets, and making them available for routine data mining, facilitates research into the mechanisms by which xenobiotics and endocrine-disrupting chemicals subvert conventional NR signaling modalities. PMID:27409825

Research Resource: A Reference Transcriptome for Constitutive Androstane Receptor and Pregnane X Receptor Xenobiotic Signaling.

PubMed

Ochsner, Scott A; Tsimelzon, Anna; Dong, Jianrong; Coarfa, Cristian; McKenna, Neil J

2016-08-01

The pregnane X receptor (PXR) (PXR/NR1I3) and constitutive androstane receptor (CAR) (CAR/NR1I2) members of the nuclear receptor (NR) superfamily of ligand-regulated transcription factors are well-characterized mediators of xenobiotic and endocrine-disrupting chemical signaling. The Nuclear Receptor Signaling Atlas maintains a growing library of transcriptomic datasets involving perturbations of NR signaling pathways, many of which involve perturbations relevant to PXR and CAR xenobiotic signaling. Here, we generated a reference transcriptome based on the frequency of differential expression of genes across 159 experiments compiled from 22 datasets involving perturbations of CAR and PXR signaling pathways. In addition to the anticipated overrepresentation in the reference transcriptome of genes encoding components of the xenobiotic stress response, the ranking of genes involved in carbohydrate metabolism and gonadotropin action sheds mechanistic light on the suspected role of xenobiotics in metabolic syndrome and reproductive disorders. Gene Set Enrichment Analysis showed that although acetaminophen, chlorpromazine, and phenobarbital impacted many similar gene sets, differences in direction of regulation were evident in a variety of processes. Strikingly, gene sets representing genes linked to Parkinson's, Huntington's, and Alzheimer's diseases were enriched in all 3 transcriptomes. The reference xenobiotic transcriptome will be supplemented with additional future datasets to provide the community with a continually updated reference transcriptomic dataset for CAR- and PXR-mediated xenobiotic signaling. Our study demonstrates how aggregating and annotating transcriptomic datasets, and making them available for routine data mining, facilitates research into the mechanisms by which xenobiotics and endocrine-disrupting chemicals subvert conventional NR signaling modalities.

Transcriptomic analyses and leukocyte telomere length measurement in subjects exposed to severe recent stressful life events.

PubMed

Lopizzo, N; Tosato, S; Begni, V; Tomassi, S; Cattane, N; Barcella, M; Turco, G; Ruggeri, M; Riva, M A; Pariante, C M; Cattaneo, A

2017-02-21

Stressful life events occurring in adulthood have been found able to affect mood and behavior, thus increasing the vulnerability for several stress-related psychiatric disorders. However, although there is plenty of clinical data supporting an association between stressful life events in adulthood and an enhanced vulnerability for psychopathology, the underlying molecular mechanisms are still poorly investigated. Thus, in this study we performed peripheral/whole-genome transcriptomic analyses in blood samples obtained from 53 adult subjects characterized for recent stressful life events occurred within the previous 6 months. Transcriptomic data were analyzed using Partek Genomics Suite; pathway and network analyses were performed using Ingenuity Pathway Analysis and GeneMANIA Software. We found 207 genes significantly differentially expressed in adult subjects who reported recent stressful life experiences (n=21) compared with those without such experiences (n=32). Moreover, the same subjects exposed to such stressful experiences showed a reduction in leukocyte telomere length. A correlation analyses between telomere length and transcriptomic data indicated an association between the exposures to recent stressful life events and the modulation of several pathways, mainly involved in immune-inflammatory-related processes and oxidative stress, such as natural killer cell signaling, interleukin-1 (IL-1) signaling, MIF regulation of innate immunity and IL-6 signaling. Our data suggest an association between exposures to recent stressful life events in adulthood and alterations in the immune, inflammatory and oxidative stress pathways, which could be also involved in the negative effect of stressful life events on leukocyte telomere length. The modulation of these mechanisms may underlie the clinical association between the exposure to recent Stressful life events in adulthood and an enhanced vulnerability to develop psychiatric diseases in adulthood.

Response of Methylocystis sp. Strain SC2 to Salt Stress: Physiology, Global Transcriptome, and Amino Acid Profiles.

PubMed

Han, Dongfei; Link, Hannes; Liesack, Werner

2017-08-11

Soil microorganisms have to rapidly respond to salt-induced osmotic stress. Type II methanotrophs of the genus Methylocystis are widely distributed in upland soils, but are known to have a low salt tolerance. Here, we tested the ability of Methylocystis sp. strain SC2 to adapt to increased salinity. When exposed to 0.75% NaCl, methane oxidation was completely inhibited for 2.25 h and fully recovered within 6 h. Growth was inhibited for 23.5 h and then fully recovered. Its transcriptome was profiled after 0 min (control), 45 min (early response) and 14 h (late response) of stress exposure. Physiological and transcriptomic stress response corresponded well. Salt stress induced differential expression of 301 genes, with sigma factor σ 32 being a major controller of the transcriptional stress response. The transcript levels of nearly all the genes involved in oxidizing CH 4 to CO 2 remained unaffected, while gene expression involved in energy-yielding reactions ( nuoEFGHI ) recovered concomitantly with methane oxidation from salt stress shock. Glutamate acted as an osmoprotectant. Its accumulation in late response corresponded to increased production of glutamate dehydrogenase 1. Chromosomal genes whose products (stress-induced protein, DNA-binding protein from starved cells, and CsbD family protein) are known to confer stress tolerance showed increased expression. On plasmid pBSC2-1, genes encoding type IV secretion system and single-strand DNA-binding protein were upregulated in late response, suggesting stress-induced activation of the plasmid-borne conjugation machinery. Collectively, our results show that Methylocystis sp. strain SC2 is able to adapt to salt stress, but only within a narrow range of salinities. Importance Besides the oxic interface of methanogenic environments, Methylocystis spp. are widely distributed in upland soils where they may contribute to the oxidation of atmospheric methane. However, little is known about their ability to cope with changes in moisture content and soil salinity. Growth and methane oxidation of Methylocystis sp. strain SC2 was not affected by the presence of 0.5% NaCl, while 1% NaCl completely inhibited its activities. This places strain SC2 into the low salt tolerance range reported for other Methylocystis spp. Our results show that, albeit in a narrow range, strain SC2 is able to respond and adapt to salinity changes. It possesses various stress-response mechanisms, which allows for a full resumption of its activities within 23.5 hours when exposed to 0.75% NaCl. Presumably, these mechanisms allow Methylocystis spp., such as strain SC2, to thrive in upland soils and to adapt to certain fluctuations in soil salinity. Copyright © 2017 American Society for Microbiology.

Integrating Omics and Alternative Splicing Reveals Insights into Grape Response to High Temperature1[OPEN

PubMed Central

Jiang, Jianfu; Liu, Xinna; Liu, Guotian; Li, Shaohua

2017-01-01

Heat stress is one of the primary abiotic stresses that limit crop production. Grape (Vitis vinifera) is a cultivated fruit with high economic value throughout the world, with its growth and development often influenced by high temperature. Alternative splicing (AS) is a widespread phenomenon increasing transcriptome and proteome diversity. We conducted high-temperature treatments (35°C, 40°C, and 45°C) on grapevines and assessed transcriptomic (especially AS) and proteomic changes in leaves. We found that nearly 70% of the genes were alternatively spliced under high temperature. Intron retention (IR), exon skipping, and alternative donor/acceptor sites were markedly induced under different high temperatures. Among all differential AS events, IR was the most abundant up- and down-regulated event. Moreover, the occurrence frequency of IR events at 40°C and 45°C was far higher than at 35°C. These results indicated that AS, especially IR, is an important posttranscriptional regulatory event during grape leaf responses to high temperature. Proteomic analysis showed that protein levels of the RNA-binding proteins SR45, SR30, and SR34 and the nuclear ribonucleic protein U1A gradually rose as ambient temperature increased, which revealed a reason why AS events occurred more frequently under high temperature. After integrating transcriptomic and proteomic data, we found that heat shock proteins and some important transcription factors such as MULTIPROTEIN BRIDGING FACTOR1c and HEAT SHOCK TRANSCRIPTION FACTOR A2 were involved mainly in heat tolerance in grape through up-regulating transcriptional (especially modulated by AS) and translational levels. To our knowledge, these results provide the first evidence for grape leaf responses to high temperature at simultaneous transcriptional, posttranscriptional, and translational levels. PMID:28049741

Integrating Omics and Alternative Splicing Reveals Insights into Grape Response to High Temperature.

PubMed

Jiang, Jianfu; Liu, Xinna; Liu, Chonghuai; Liu, Guotian; Li, Shaohua; Wang, Lijun

2017-02-01

Heat stress is one of the primary abiotic stresses that limit crop production. Grape (Vitis vinifera) is a cultivated fruit with high economic value throughout the world, with its growth and development often influenced by high temperature. Alternative splicing (AS) is a widespread phenomenon increasing transcriptome and proteome diversity. We conducted high-temperature treatments (35°C, 40°C, and 45°C) on grapevines and assessed transcriptomic (especially AS) and proteomic changes in leaves. We found that nearly 70% of the genes were alternatively spliced under high temperature. Intron retention (IR), exon skipping, and alternative donor/acceptor sites were markedly induced under different high temperatures. Among all differential AS events, IR was the most abundant up- and down-regulated event. Moreover, the occurrence frequency of IR events at 40°C and 45°C was far higher than at 35°C. These results indicated that AS, especially IR, is an important posttranscriptional regulatory event during grape leaf responses to high temperature. Proteomic analysis showed that protein levels of the RNA-binding proteins SR45, SR30, and SR34 and the nuclear ribonucleic protein U1A gradually rose as ambient temperature increased, which revealed a reason why AS events occurred more frequently under high temperature. After integrating transcriptomic and proteomic data, we found that heat shock proteins and some important transcription factors such as MULTIPROTEIN BRIDGING FACTOR1c and HEAT SHOCK TRANSCRIPTION FACTOR A2 were involved mainly in heat tolerance in grape through up-regulating transcriptional (especially modulated by AS) and translational levels. To our knowledge, these results provide the first evidence for grape leaf responses to high temperature at simultaneous transcriptional, posttranscriptional, and translational levels. © 2017 American Society of Plant Biologists. All Rights Reserved.

Rapid Acclimation Ability Mediated by Transcriptome Changes in Reef-Building Corals.

PubMed

Bay, Rachael A; Palumbi, Stephen R

2015-05-15

Population response to environmental variation involves adaptation, acclimation, or both. For long-lived organisms, acclimation likely generates a faster response but is only effective if the rates and limits of acclimation match the dynamics of local environmental variation. In coral reef habitats, heat stress from extreme ocean warming can occur over several weeks, resulting in symbiont expulsion and widespread coral death. However, transcriptome regulation during short-term acclimation is not well understood. We examined acclimation during a 11-day experiment in the coral Acropora nana. We acclimated colonies to three regimes: ambient temperature (29 °C), increased stable temperature (31 °C), and variable temperature (29-33 °C), mimicking local heat stress conditions. Within 7-11 days, individuals acclimated to increased temperatures had higher tolerance to acute heat stress. Despite physiological changes, no gene expression changes occurred during acclimation before acute heat stress. However, we found strikingly different transcriptional responses to heat stress between acclimation treatments across 893 contigs. Across these contigs, corals acclimated to higher temperatures (31 °C or 29-33 °C) exhibited a muted stress response--the magnitude of expression change before and after heat stress was less than in 29 °C acclimated corals. Our results show that corals have a rapid phase of acclimation that substantially increases their heat resilience within 7 days and that alters their transcriptional response to heat stress. This is in addition to a previously observed longer term response, distinguishable by its shift in baseline expression, under nonstressful conditions. Such rapid acclimation may provide some protection for this species of coral against slow onset of warming ocean temperatures. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Editor's Highlight: Hydroxyurea Exposure Activates the P53 Signaling Pathway in Murine Organogenesis-Stage Embryos.

PubMed

El Husseini, Nazem; Schlisser, Ava E; Hales, Barbara F

2016-08-01

Hydroxyurea, an anticancer agent and potent teratogen, induces oxidative stress and activates a DNA damage response pathway in the gestation day (GD) 9 mouse embryo. To delineate the stress response pathways activated by this drug, we investigated the effect of hydroxyurea exposure on the transcriptome of GD 9 embryos. Timed pregnant CD-1 mice were treated with saline or hydroxyurea (400 mg/kg or 600 mg/kg) on GD 9; embryonic gene and protein expression were examined 3 h later. Microarray analysis revealed that the expression of 1346 probe sets changed significantly in embryos exposed to hydroxyurea compared with controls; the P53 signaling pathway was highly affected. In addition, P53 related family members, P63 and P73, were predicted to be activated and had common and unique downstream targets. Western blot analysis revealed that active phospho-P53 was significantly increased in drug-exposed embryos; confocal microscopy showed that the translocation of phospho-P53 to the nucleus was widespread in the embryo. Furthermore, qRT-PCR showed that the expression of P53-regulated genes (Cdkn1A, Fas, and Trp53inp1) was significantly upregulated in hydroxyurea-exposed embryos; the concentration of the redox sensitive P53INP1 protein was also increased in a hydroxyurea dose-dependent fashion. Thus, hydroxyurea elicits a significant effect on the transcriptome of the organogenesis stage murine embryo, activating several key developmental signaling pathways related to DNA damage and oxidative stress. We propose that the P53 pathway plays a central role in the embryonic stress response and the developmental outcome after teratogen exposure. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Transcriptome analysis of WRKY gene family in Oryza officinalis Wall ex Watt and WRKY genes involved in responses to Xanthomonas oryzae pv. oryzae stress

PubMed Central

Jiang, Chunmiao; Shen, Qingxi J.; Wang, Bo; He, Bin; Xiao, Suqin; Chen, Ling; Yu, Tengqiong; Ke, Xue; Zhong, Qiaofang; Fu, Jian; Chen, Yue; Wang, Lingxian; Yin, Fuyou; Zhang, Dunyu; Ghidan, Walid; Huang, Xingqi; Cheng, Zaiquan

2017-01-01

Oryza officinalis Wall ex Watt, a very important and special wild rice species, shows abundant genetic diversity and disease resistance features, especially high resistance to bacterial blight. The molecular mechanisms of bacterial blight resistance in O. officinalis have not yet been elucidated. The WRKY transcription factor family is one of the largest gene families involved in plant growth, development and stress response. However, little is known about the numbers, structure, molecular phylogenetics, and expression of the WRKY genes under Xanthomonas oryzae pv. oryzae (Xoo) stress in O. officinalis due to lacking of O. officinalis genome. Therefore, based on the RNA-sequencing data of O. officinalis, we performed a comprehensive study of WRKY genes in O. officinalis and identified 89 OoWRKY genes. Then 89 OoWRKY genes were classified into three groups based on the WRKY domains and zinc finger motifs. Phylogenetic analysis strongly supported that the evolution of OoWRKY genes were consistent with previous studies of WRKYs, and subgroup IIc OoWRKY genes were the original ancestors of some group II and group III OoWRKYs. Among the 89 OoWRKY genes, eight OoWRKYs displayed significantly different expression (>2-fold, p<0.01) in the O. officinalis transcriptome under Xoo strains PXO99 and C5 stress 48 h, suggesting these genes might play important role in PXO99 and C5 stress responses in O. officinalis. QRT-PCR analysis and confirmation of eight OoWRKYs expression patterns revealed that they responded strongly to PXO99 and C5 stress 24 h, 48 h, and 72 h, and the trends of these genes displaying marked changes were consistent with the 48 h RNA-sequencing data, demonstrated these genes played important roles in response to biotic stress and might even involved in the bacterial blight resistance. Tissue expression profiles of eight OoWRKY genes revealed that they were highly expressed in root, stem, leaf, and flower, especially in leaf (except OoWRKY71), suggesting these genes might be also important for plant growth and organ development. In this study, we analyzed the WRKY family of transcription factors in O.officinalis. Insight was gained into the classification, evolution, and function of the OoWRKY genes, revealing the putative roles of eight significantly different expression OoWRKYs in Xoo strains PXO99 and C5 stress responses in O.officinalis. This study provided a better understanding of the evolution and functions of O. officinalis WRKY genes, and suggested that manipulating eight significantly different expression OoWRKYs would enhance resistance to bacterial blight. PMID:29190793

Transcriptome analysis of WRKY gene family in Oryza officinalis Wall ex Watt and WRKY genes involved in responses to Xanthomonas oryzae pv. oryzae stress.

PubMed

Jiang, Chunmiao; Shen, Qingxi J; Wang, Bo; He, Bin; Xiao, Suqin; Chen, Ling; Yu, Tengqiong; Ke, Xue; Zhong, Qiaofang; Fu, Jian; Chen, Yue; Wang, Lingxian; Yin, Fuyou; Zhang, Dunyu; Ghidan, Walid; Huang, Xingqi; Cheng, Zaiquan

2017-01-01

Oryza officinalis Wall ex Watt, a very important and special wild rice species, shows abundant genetic diversity and disease resistance features, especially high resistance to bacterial blight. The molecular mechanisms of bacterial blight resistance in O. officinalis have not yet been elucidated. The WRKY transcription factor family is one of the largest gene families involved in plant growth, development and stress response. However, little is known about the numbers, structure, molecular phylogenetics, and expression of the WRKY genes under Xanthomonas oryzae pv. oryzae (Xoo) stress in O. officinalis due to lacking of O. officinalis genome. Therefore, based on the RNA-sequencing data of O. officinalis, we performed a comprehensive study of WRKY genes in O. officinalis and identified 89 OoWRKY genes. Then 89 OoWRKY genes were classified into three groups based on the WRKY domains and zinc finger motifs. Phylogenetic analysis strongly supported that the evolution of OoWRKY genes were consistent with previous studies of WRKYs, and subgroup IIc OoWRKY genes were the original ancestors of some group II and group III OoWRKYs. Among the 89 OoWRKY genes, eight OoWRKYs displayed significantly different expression (>2-fold, p<0.01) in the O. officinalis transcriptome under Xoo strains PXO99 and C5 stress 48 h, suggesting these genes might play important role in PXO99 and C5 stress responses in O. officinalis. QRT-PCR analysis and confirmation of eight OoWRKYs expression patterns revealed that they responded strongly to PXO99 and C5 stress 24 h, 48 h, and 72 h, and the trends of these genes displaying marked changes were consistent with the 48 h RNA-sequencing data, demonstrated these genes played important roles in response to biotic stress and might even involved in the bacterial blight resistance. Tissue expression profiles of eight OoWRKY genes revealed that they were highly expressed in root, stem, leaf, and flower, especially in leaf (except OoWRKY71), suggesting these genes might be also important for plant growth and organ development. In this study, we analyzed the WRKY family of transcription factors in O.officinalis. Insight was gained into the classification, evolution, and function of the OoWRKY genes, revealing the putative roles of eight significantly different expression OoWRKYs in Xoo strains PXO99 and C5 stress responses in O.officinalis. This study provided a better understanding of the evolution and functions of O. officinalis WRKY genes, and suggested that manipulating eight significantly different expression OoWRKYs would enhance resistance to bacterial blight.

Global transcriptome analysis of eukaryotic genes affected by gromwell extract.

PubMed

Bang, Soohyun; Lee, Dohyun; Kim, Hanhe; Park, Jiyong; Bahn, Yong-Sun

2014-02-01

Gromwell is known to have diverse pharmacological, cosmetic and nutritional benefits for humans. Nevertheless, the biological influence of gromwell extract (GE) on the general physiology of eukaryotic cells remains unknown. In this study a global transcriptome analysis was performed to identify genes affected by the addition of GE with Cryptococcus neoformans as the model system. In response to GE treatment, genes involved in signal transduction were immediately regulated, and the evolutionarily conserved sets of genes involved in the core cellular functions, including DNA replication, RNA transcription/processing and protein translation/processing, were generally up-regulated. In contrast, a number of genes involved in carbohydrate metabolism and transport, inorganic ion transport and metabolism, post-translational modification/protein turnover/chaperone functions and signal transduction were down-regulated. Among the GE-responsive genes that are also evolutionarily conserved in the human genome, the expression patterns of YSA1, TPO2, CFO1 and PZF1 were confirmed by northern blot analysis. Based on the functional characterization of some GE-responsive genes, it was found that GE treatment may promote cellular tolerance against a variety of environmental stresses in eukaryotes. GE treatment affects the expression levels of a significant portion of the Cryptococcus genome, implying that GE significantly affects the general physiology of eukaryotic cells. © 2013 Society of Chemical Industry.

Genome-wide identification of WRKY family genes and their response to cold stress in Vitis vinifera

PubMed Central

2014-01-01

Background WRKY transcription factors are one of the largest families of transcriptional regulators in plants. WRKY genes are not only found to play significant roles in biotic and abiotic stress response, but also regulate growth and development. Grapevine (Vitis vinifera) production is largely limited by stressful climate conditions such as cold stress and the role of WRKY genes in the survival of grapevine under these conditions remains unknown. Results We identified a total of 59 VvWRKYs from the V. vinifera genome, belonging to four subgroups according to conserved WRKY domains and zinc-finger structure. The majority of VvWRKYs were expressed in more than one tissue among the 7 tissues examined which included young leaves, mature leaves, tendril, stem apex, root, young fruits and ripe fruits. Publicly available microarray data suggested that a subset of VvWRKYs was activated in response to diverse stresses. Quantitative real-time PCR (qRT-PCR) results demonstrated that the expression levels of 36 VvWRKYs are changed following cold exposure. Comparative analysis was performed on data from publicly available microarray experiments, previous global transcriptome analysis studies, and qRT-PCR. We identified 15 VvWRKYs in at least two of these databases which may relate to cold stress. Among them, the transcription of three genes can be induced by exogenous ABA application, suggesting that they can be involved in an ABA-dependent signaling pathway in response to cold stress. Conclusions We identified 59 VvWRKYs from the V. vinifera genome and 15 of them showed cold stress-induced expression patterns. These genes represented candidate genes for future functional analysis of VvWRKYs involved in the low temperature-related signal pathways in grape. PMID:24755338

Transcriptomic Profiling of Soybean in Response to High-Intensity UV-B Irradiation Reveals Stress Defense Signaling

PubMed Central

Yoon, Min Young; Kim, Moon Young; Shim, Sangrae; Kim, Kyung Do; Ha, Jungmin; Shin, Jin Hee; Kang, Sungtaeg; Lee, Suk-Ha

2016-01-01

The depletion of the ozone layer in the stratosphere has led to a dramatic spike in ultraviolet B (UV-B) intensity and increased UV-B light levels. The direct absorption of high-intensity UV-B induces complex abiotic stresses in plants, including excessive light exposure, heat, and dehydration. However, UV-B stress signaling mechanisms in plants including soybean (Glycine max [L.]) remain poorly understood. Here, we surveyed the overall transcriptional responses of two soybean genotypes, UV-B-sensitive Cheongja 3 and UV-B-resistant Buseok, to continuous UV-B irradiation for 0 (control), 0.5, and 6 h using RNA-seq analysis. Homology analysis using UV-B-related genes from Arabidopsis thaliana revealed differentially expressed genes (DEGs) likely involved in UV-B stress responses. Functional classification of the DEGs showed that the categories of immune response, stress defense signaling, and reactive oxygen species (ROS) metabolism were over-represented. UV-B-resistant Buseok utilized phosphatidic acid-dependent signaling pathways (based on subsequent reactions of phospholipase C and diacylglycerol kinase) rather than phospholipase D in response to UV-B exposure at high fluence rates, and genes involved in its downstream pathways, such as ABA signaling, mitogen-activated protein kinase cascades, and ROS overproduction, were upregulated in this genotype. In addition, the DEGs for TIR-NBS-LRR and heat shock proteins are positively activated. These results suggest that defense mechanisms against UV-B stress at high fluence rates are separate from the photomorphogenic responses utilized by plants to adapt to low-level UV light. Our study provides valuable information for deep understanding of UV-B stress defense mechanisms and for the development of resistant soybean genotypes that survive under high-intensity UV-B stress. PMID:28066473

Activation of Two Different Resistance Mechanisms in Saccharomyces cerevisiae upon Exposure to Octanoic and Decanoic Acids▿ †

PubMed Central

Legras, J. L.; Erny, C.; Le Jeune, C.; Lollier, M.; Adolphe, Y.; Demuyter, C.; Delobel, P.; Blondin, B.; Karst, F.

2010-01-01

Medium-chain fatty acids (octanoic and decanoic acids) are well known as fermentation inhibitors. During must fermentation, the toxicity of these fatty acids is enhanced by ethanol and low pH, which favors their entrance in the cell, resulting in a decrease of internal pH. We present here the characterization of the mechanisms involved in the establishment of the resistance to these fatty acids. The analysis of the transcriptome response to the exposure to octanoic and decanoic acids revealed that two partially overlapping mechanisms are activated; both responses share many genes with an oxidative stress response, but some key genes were activated differentially. The transcriptome response to octanoic acid stress can be described mainly as a weak acid response, and it involves Pdr12p as the main transporter. The phenotypic analysis of knocked-out strains confirmed the role of the Pdr12p transporter under the control of WAR1 but also revealed the involvement of the Tpo1p major facilitator superfamily proteins (MFS) transporter in octanoic acid expulsion. In contrast, the resistance to decanoic acid is composite. It also involves the transporter Tpo1p and includes the activation of several genes of the beta-oxidation pathway and ethyl ester synthesis. Indeed, the induction of FAA1 and EEB1, coding for a long-chain fatty acyl coenzyme A synthetase and an alcohol acyltransferase, respectively, suggests a detoxification pathway through the production of decanoate ethyl ester. These results are confirmed by the sensitivity of strains bearing deletions for the transcription factors encoded by PDR1, STB5, OAF1, and PIP2 genes. PMID:20851956

Prominent alterations of wild barley leaf transcriptome in response to individual and combined drought acclimation and heat shock conditions.

PubMed

Ashoub, Ahmed; Müller, Niels; Jiménez-Gómez, José M; Brüggemann, Wolfgang

2018-05-01

Under field conditions, drought and heat stress typically happen simultaneously and their negative impact on the agricultural production is expected to increase worldwide under the climate change scenario. In this study, we performed RNA-sequencing analysis on leaves of wild barley (Hordeum spontaneum) originated from the northern coastal region of Egypt following individual drought acclimation (DA) and heat shock (HS) treatments and their combination (CS, combined stresses) to distinguish the unique and shared differentially expressed genes (DEG). Results indicated that the number of unique genes that were differentially expressed following HS treatment exceeded the number of those expressed following DA. In addition, the number of genes that were uniquely differentially expressed in response to CS treatment exceeded the number of those of shared responses to individual DA and HS treatments. These results indicate a better adaptation of the Mediterranean wild barley to drought conditions when compared with heat stress. It also manifests that the wild barley response to CS tends to be unique rather than common. Annotation of DEG showed that metabolic processes were the most influenced biological function in response to the applied stresses. © 2017 Scandinavian Plant Physiology Society.

Physiological genomics of response to soil drying in diverse Arabidopsis accessions.

PubMed

Des Marais, David L; McKay, John K; Richards, James H; Sen, Saunak; Wayne, Tierney; Juenger, Thomas E

2012-03-01

Arabidopsis thaliana, like many species, is characterized by abundant genetic variation. This variation is rapidly being cataloged at the sequence level, but careful dissection of genetic variation in whole-organism responses to stresses encountered in the natural environment are lacking; this functional variation can be exploited as a natural mutant screen to determine gene function. Here, we document physiological and transcriptomic response to soil drying in 17 natural accessions of Arabidopsis. By imposing ecologically realistic stress conditions, we found that acclimation in Arabidopsis involved a strong signature of increased investment in photosynthesis, carbohydrate turnover, and root growth. Our results extend previous work in the Columbia accession suggesting that abscisic acid signaling pathways play an important role in drought stress response. We also identified several mechanisms, including an increase in leaf nitrogen concentration and upregulation of two-component signaling relays, that were common to most natural accessions but had not been identified in studies using only the Columbia accession. Principal component analysis reveals strong correlations between suites of genes and specific physiological responses to stress. The functional variants we identified may represent adaptive mutations in natural habitats and useful variants for agronomic improvement of crop species.

Physiological Genomics of Response to Soil Drying in Diverse Arabidopsis Accessions[W][OA

PubMed Central

Des Marais, David L.; McKay, John K.; Richards, James H.; Sen, Saunak; Wayne, Tierney; Juenger, Thomas E.

2012-01-01

Arabidopsis thaliana, like many species, is characterized by abundant genetic variation. This variation is rapidly being cataloged at the sequence level, but careful dissection of genetic variation in whole-organism responses to stresses encountered in the natural environment are lacking; this functional variation can be exploited as a natural mutant screen to determine gene function. Here, we document physiological and transcriptomic response to soil drying in 17 natural accessions of Arabidopsis. By imposing ecologically realistic stress conditions, we found that acclimation in Arabidopsis involved a strong signature of increased investment in photosynthesis, carbohydrate turnover, and root growth. Our results extend previous work in the Columbia accession suggesting that abscisic acid signaling pathways play an important role in drought stress response. We also identified several mechanisms, including an increase in leaf nitrogen concentration and upregulation of two-component signaling relays, that were common to most natural accessions but had not been identified in studies using only the Columbia accession. Principal component analysis reveals strong correlations between suites of genes and specific physiological responses to stress. The functional variants we identified may represent adaptive mutations in natural habitats and useful variants for agronomic improvement of crop species. PMID:22408074

Reciprocal osmotic challenges reveal mechanisms of divergence in phenotypic plasticity in the killifish Fundulus heteroclitus.

PubMed

Brennan, Reid S; Galvez, Fernando; Whitehead, Andrew

2015-04-15

The killifish Fundulus heteroclitus is an estuarine species with broad physiological plasticity, enabling acclimation to diverse stressors. Previous work suggests that freshwater populations expanded their physiology to accommodate low salinity environments; however, it is unknown whether this compromises their tolerance to high salinity. We used a comparative approach to investigate the mechanisms of a derived freshwater phenotype and the fate of an ancestral euryhaline phenotype after invasion of a freshwater environment. We compared physiological and transcriptomic responses to high- and low-salinity stress in fresh and brackish water populations and found an enhanced plasticity to low salinity in the freshwater population coupled with a reduced ability to acclimate to high salinity. Transcriptomic data identified genes with a conserved common response, a conserved salinity-dependent response and responses associated with population divergence. Conserved common acclimation responses revealed stress responses and alterations in cell-cycle regulation as important mechanisms in the general osmotic response. Salinity-specific responses included the regulation of genes involved in ion transport, intracellular calcium, energetic processes and cellular remodeling. Genes diverged between populations were primarily those showing salinity-specific expression and included those regulating polyamine homeostasis and the cell cycle. Additionally, when populations were matched with their native salinity, expression patterns were consistent with the concept of 'transcriptomic resilience', suggesting local adaptation. These findings provide insight into the fate of a plastic phenotype after a shift in environmental salinity and help to reveal mechanisms allowing for euryhalinity. © 2015. Published by The Company of Biologists Ltd.

Comparative transcriptome profiling of potassium starvation responsiveness in two contrasting watermelon genotypes.

PubMed

Fan, Molin; Huang, Yuan; Zhong, Yaqin; Kong, Qiusheng; Xie, Junjun; Niu, Mengliang; Xu, Yong; Bie, Zhilong

2014-02-01

Potassium (K) is one of the essential nutrients for crops, and K⁺ deficiency highly restricts crop yield and quality. Watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] is an economically important crop that often suffers from K⁺ deficiency. To elucidate the underlying tolerance mechanism of watermelon to K⁺ deficiency and to improve K efficiency of watermelon and other crops in the future, two watermelon genotypes, namely, YS and 8424, that exhibit contrasting K efficiencies were studied to compare their response mechanisms to K⁺ deficiency. YS was more tolerant of K⁺ deficiency and displayed less inhibited root growth than 8424. Roots of YS and 8424 seedlings with or without K⁺ supply were harvested at 6 and 120 h after treatment (HAT), and their transcriptomes were analyzed by Illumina RNA sequencing. Different regulation mechanisms of the root K⁺-uptake genes for short- and long-term stress were observed. Genes involved in jasmonic acid and reactive oxygen species production; Ca²⁺ and receptor-like kinase signaling; lignin biosynthesis; and other stress-related genes were repressed in YS, whereas a large number of such stress-related genes were induced in 8424 at 120 HAT. These results suggested that repressed defense and stress response can save energy for better root growth in YS, which can facilitate K⁺ uptake and increase K efficiency and tolerance to K⁺ deficiency. This study presents the first global root transcriptome in watermelon and provides new insights into the molecular mechanisms underlying tolerance to K⁺ deficiency of K-efficient watermelon genotypes.

Genome-scale cold stress response regulatory networks in ten Arabidopsis thaliana ecotypes

PubMed Central

2013-01-01

Background Low temperature leads to major crop losses every year. Although several studies have been conducted focusing on diversity of cold tolerance level in multiple phenotypically divergent Arabidopsis thaliana (A. thaliana) ecotypes, genome-scale molecular understanding is still lacking. Results In this study, we report genome-scale transcript response diversity of 10 A. thaliana ecotypes originating from different geographical locations to non-freezing cold stress (10°C). To analyze the transcriptional response diversity, we initially compared transcriptome changes in all 10 ecotypes using Arabidopsis NimbleGen ATH6 microarrays. In total 6061 transcripts were significantly cold regulated (p < 0.01) in 10 ecotypes, including 498 transcription factors and 315 transposable elements. The majority of the transcripts (75%) showed ecotype specific expression pattern. By using sequence data available from Arabidopsis thaliana 1001 genome project, we further investigated sequence polymorphisms in the core cold stress regulon genes. Significant numbers of non-synonymous amino acid changes were observed in the coding region of the CBF regulon genes. Considering the limited knowledge about regulatory interactions between transcription factors and their target genes in the model plant A. thaliana, we have adopted a powerful systems genetics approach- Network Component Analysis (NCA) to construct an in-silico transcriptional regulatory network model during response to cold stress. The resulting regulatory network contained 1,275 nodes and 7,720 connections, with 178 transcription factors and 1,331 target genes. Conclusions A. thaliana ecotypes exhibit considerable variation in transcriptome level responses to non-freezing cold stress treatment. Ecotype specific transcripts and related gene ontology (GO) categories were identified to delineate natural variation of cold stress regulated differential gene expression in the model plant A. thaliana. The predicted regulatory network model was able to identify new ecotype specific transcription factors and their regulatory interactions, which might be crucial for their local geographic adaptation to cold temperature. Additionally, since the approach presented here is general, it could be adapted to study networks regulating biological process in any biological systems. PMID:24148294

Transcriptomic response of the Antarctic pteropod Limacina helicina antarctica to ocean acidification.

PubMed

Johnson, Kevin M; Hofmann, Gretchen E

2017-10-23

Ocean acidification (OA), a change in ocean chemistry due to the absorption of atmospheric CO 2 into surface oceans, challenges biogenic calcification in many marine organisms. Ocean acidification is expected to rapidly progress in polar seas, with regions of the Southern Ocean expected to experience severe OA within decades. Biologically, the consequences of OA challenge calcification processes and impose an energetic cost. In order to better characterize the response of a polar calcifier to conditions of OA, we assessed differential gene expression in the Antarctic pteropod, Limacina helicina antarctica. Experimental levels of pCO 2 were chosen to create both contemporary pH conditions, and to mimic future pH expected in OA scenarios. Significant changes in the transcriptome were observed when juvenile L. h. antarctica were acclimated for 21 days to low-pH (7.71), mid-pH (7.9) or high-pH (8.13) conditions. Differential gene expression analysis of individuals maintained in the low-pH treatment identified down-regulation of genes involved in cytoskeletal structure, lipid transport, and metabolism. High pH exposure led to increased expression and enrichment for genes involved in shell formation, calcium ion binding, and DNA binding. Significant differential gene expression was observed in four major cellular and physiological processes: shell formation, the cellular stress response, metabolism, and neural function. Across these functional groups, exposure to conditions that mimic ocean acidification led to rapid suppression of gene expression. Results of this study demonstrated that the transcriptome of the juvenile pteropod, L. h. antarctica, was dynamic and changed in response to different levels of pCO 2 . In a global change context, exposure of L. h. antarctica to the low pH, high pCO 2 OA conditions resulted in a suppression of transcripts for genes involved in key physiological processes: calcification, metabolism, and the cellular stress response. The transcriptomic response at both acute and longer-term acclimation time frames indicated that contemporary L. h. antarctica may not have the physiological plasticity necessary for adaptation to OA conditions expected in future decades. Lastly, the differential gene expression results further support the role of shelled pteropods such as L. h. antarctica as sentinel organisms for the impacts of ocean acidification.

Analysis of plant hormone profiles in response to moderate dehydration stress.

PubMed

Urano, Kaoru; Maruyama, Kyonoshin; Jikumaru, Yusuke; Kamiya, Yuji; Yamaguchi-Shinozaki, Kazuko; Shinozaki, Kazuo

2017-04-01

Plant responses to dehydration stress are mediated by highly complex molecular systems involving hormone signaling and metabolism, particularly the major stress hormone abscisic acid (ABA) and ABA-dependent gene expression. To understand the roles of plant hormones and their interactions during dehydration, we analyzed the plant hormone profiles with respect to dehydration responses in Arabidopsis thaliana wild-type (WT) plants and ABA biosynthesis mutants (nced3-2). We developed a procedure for moderate dehydration stress, and then investigated temporal changes in the profiles of ABA, jasmonic acid isoleucine (JA-Ile), salicylic acid (SA), cytokinin (trans-zeatin, tZ), auxin (indole-acetic acid, IAA), and gibberellin (GA 4 ), along with temporal changes in the expression of key genes involved in hormone biosynthesis. ABA levels increased in a bi-phasic pattern (at the early and late phases) in response to moderate dehydration stress. JA-Ile levels increased slightly in WT plants and strongly increased in nced3-2 mutant plants at 72 h after the onset of dehydration. The expression profiles of dehydration-inducible genes displayed temporal responses in an ABA-dependent manner. The early phase of ABA accumulation correlated with the expression of touch-inducible genes and was independent of factors involved in the major ABA regulatory pathway, including the ABA-responsive element-binding (AREB/ABF) transcription factor. JA-Ile, SA, and tZ were negatively regulated during the late dehydration response phase. Transcriptome analysis revealed important roles for hormone-related genes in metabolism and signaling during dehydration-induced plant responses. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

Transcriptome changes during fruit development and ripening of sweet orange (Citrus sinensis).

PubMed

Yu, Keqin; Xu, Qiang; Da, Xinlei; Guo, Fei; Ding, Yuduan; Deng, Xiuxin

2012-01-10

The transcriptome of the fruit pulp of the sweet orange variety Anliu (WT) and that of its red fleshed mutant Hong Anliu (MT) were compared to understand the dynamics and differential expression of genes expressed during fruit development and ripening. The transcriptomes of WT and MT were sampled at four developmental stages using an Illumina sequencing platform. A total of 19,440 and 18,829 genes were detected in MT and WT, respectively. Hierarchical clustering analysis revealed 24 expression patterns for the set of all genes detected, of which 20 were in common between MT and WT. Over 89% of the genes showed differential expression during fruit development and ripening in the WT. Functional categorization of the differentially expressed genes revealed that cell wall biosynthesis, carbohydrate and citric acid metabolism, carotenoid metabolism, and the response to stress were the most differentially regulated processes occurring during fruit development and ripening. A description of the transcriptomic changes occurring during fruit development and ripening was obtained in sweet orange, along with a dynamic view of the gene expression differences between the wild type and a red fleshed mutant. © 2012 Yu et al; licensee BioMed Central Ltd.

Global Landscape of a Co-Expressed Gene Network in Barley and its Application to Gene Discovery in Triticeae Crops

PubMed Central

Mochida, Keiichi; Uehara-Yamaguchi, Yukiko; Yoshida, Takuhiro; Sakurai, Tetsuya; Shinozaki, Kazuo

2011-01-01

Accumulated transcriptome data can be used to investigate regulatory networks of genes involved in various biological systems. Co-expression analysis data sets generated from comprehensively collected transcriptome data sets now represent efficient resources that are capable of facilitating the discovery of genes with closely correlated expression patterns. In order to construct a co-expression network for barley, we analyzed 45 publicly available experimental series, which are composed of 1,347 sets of GeneChip data for barley. On the basis of a gene-to-gene weighted correlation coefficient, we constructed a global barley co-expression network and classified it into clusters of subnetwork modules. The resulting clusters are candidates for functional regulatory modules in the barley transcriptome. To annotate each of the modules, we performed comparative annotation using genes in Arabidopsis and Brachypodium distachyon. On the basis of a comparative analysis between barley and two model species, we investigated functional properties from the representative distributions of the gene ontology (GO) terms. Modules putatively involved in drought stress response and cellulose biogenesis have been identified. These modules are discussed to demonstrate the effectiveness of the co-expression analysis. Furthermore, we applied the data set of co-expressed genes coupled with comparative analysis in attempts to discover potentially Triticeae-specific network modules. These results demonstrate that analysis of the co-expression network of the barley transcriptome together with comparative analysis should promote the process of gene discovery in barley. Furthermore, the insights obtained should be transferable to investigations of Triticeae plants. The associated data set generated in this analysis is publicly accessible at http://coexpression.psc.riken.jp/barley/. PMID:21441235

Cellular stress responses to chronic heat shock and shell damage in temperate Mya truncata.

PubMed

Sleight, Victoria A; Peck, Lloyd S; Dyrynda, Elisabeth A; Smith, Valerie J; Clark, Melody S

2018-05-12

Acclimation, via phenotypic flexibility, is a potential means for a fast response to climate change. Understanding the molecular mechanisms underpinning phenotypic flexibility can provide a fine-scale cellular understanding of how organisms acclimate. In the last 30 years, Mya truncata populations around the UK have faced an average increase in sea surface temperature of 0.7 °C and further warming of between 1.5 and 4 °C, in all marine regions adjacent to the UK, is predicted by the end of the century. Hence, data are required on the ability of M. truncata to acclimate to physiological stresses, and most notably, chronic increases in temperature. Animals in the present study were exposed to chronic heat-stress for 2 months prior to shell damage and subsequently, only 3, out of 20 damaged individuals, were able to repair their shells within 2 weeks. Differentially expressed genes (between control and damaged animals) were functionally enriched with processes relating to cellular stress, the immune response and biomineralisation. Comparative transcriptomics highlighted genes, and more broadly molecular mechanisms, that are likely to be pivotal in this lack of acclimation. This study demonstrates that discovery-led transcriptomic profiling of animals during stress-response experiments can shed light on the complexity of biological processes and changes within organisms that can be more difficult to detect at higher levels of biological organisation.

Acclimation of Antarctic Chlamydomonas to the sea-ice environment: a transcriptomic analysis.

PubMed

Liu, Chenlin; Wang, Xiuliang; Wang, Xingna; Sun, Chengjun

2016-07-01

The Antarctic green alga Chlamydomonas sp. ICE-L was isolated from sea ice. As a psychrophilic microalga, it can tolerate the environmental stress in the sea-ice brine, such as freezing temperature and high salinity. We performed a transcriptome analysis to identify freezing stress responding genes and explore the extreme environmental acclimation-related strategies. Here, we show that many genes in ICE-L transcriptome that encoding PUFA synthesis enzymes, molecular chaperon proteins, and cell membrane transport proteins have high similarity to the gens from Antarctic bacteria. These ICE-L genes are supposed to be acquired through horizontal gene transfer from its symbiotic microbes in the sea-ice brine. The presence of these genes in both sea-ice microalgae and bacteria indicated the biological processes they involved in are possibly contributing to ICE-L success in sea ice. In addition, the biological pathways were compared between ICE-L and its closely related sister species, Chlamydomonas reinhardtii and Volvox carteri. In ICE-L transcripome, many sequences homologous to the plant or bacteria proteins in the post-transcriptional, post-translational modification, and signal-transduction KEGG pathways, are absent in the nonpsychrophilic green algae. These complex structural components might imply enhanced stress adaptation capacity. At last, differential gene expression analysis at the transcriptome level of ICE-L indicated that genes that associated with post-translational modification, lipid metabolism, and nitrogen metabolism are responding to the freezing treatment. In conclusion, the transcriptome of Chlamydomonas sp. ICE-L is very useful for exploring the mutualistic interaction between microalgae and bacteria in sea ice; and discovering the specific genes and metabolism pathways responding to the freezing acclimation in psychrophilic microalgae.

Population-Level Transcriptomic Responses of the Southern Ocean Salp Salpa thompsoni to Environment Variability of the Western Antarctic Peninsula Region

NASA Astrophysics Data System (ADS)

Bucklin, A. C.; Batta Lona, P. G.; Maas, A. E.; O'Neill, R. J.; Wiebe, P. H.

2015-12-01

In response to the changing Antarctic climate, the Southern Ocean salp Salpa thompsoni has shown altered patterns of distribution and abundance that are anticipated to have profound impacts on pelagic food webs and ecosystem dynamics. The physiological and molecular processes that underlay ecological function and biogeographical distribution are key to understanding present-day dynamics and predicting future trajectories. This study examined transcriptome-wide patterns of gene expression in relation to biological and physical oceanographic conditions in coastal, shelf and offshore waters of the Western Antarctic Peninsula (WAP) region during austral spring and summer 2011. Based on field observations and collections, seasonal changes in the distribution and abundance of salps of different life stages were associated with differences in water mass structure of the WAP. Our observations are consistent with previous suggestions that bathymetry and currents in Bransfield Strait could generate a retentive cell for an overwintering population of S. thompsoni, which may generate the characteristic salp blooms found throughout the region later in summer. The statistical analysis of transcriptome-wide patterns of gene expression revealed differences among salps collected in different seasons and from different habitats (i.e., coastal versus offshore) in the WAP. Gene expression patterns also clustered by station in austral spring - but not summer - collections, suggesting stronger heterogeneity of environmental conditions. During the summer, differentially expressed genes covered a wider range of functions, including those associated with stress responses. Future research using novel molecular transcriptomic / genomic characterization of S. thompsoni will allow more complete understanding of individual-, population-, and species-level responses to environmental variability and prediction of future dynamics of Southern Ocean food webs and ecosystems.

ABA Is Required for Plant Acclimation to a Combination of Salt and Heat Stress.

PubMed

Suzuki, Nobuhiro; Bassil, Elias; Hamilton, Jason S; Inupakutika, Madhuri A; Zandalinas, Sara Izquierdo; Tripathy, Deesha; Luo, Yuting; Dion, Erin; Fukui, Ginga; Kumazaki, Ayana; Nakano, Ruka; Rivero, Rosa M; Verbeck, Guido F; Azad, Rajeev K; Blumwald, Eduardo; Mittler, Ron

2016-01-01

Abiotic stresses such as drought, heat or salinity are a major cause of yield loss worldwide. Recent studies revealed that the acclimation of plants to a combination of different environmental stresses is unique and cannot be directly deduced from studying the response of plants to each of the different stresses applied individually. Here we report on the response of Arabidopsis thaliana to a combination of salt and heat stress using transcriptome analysis, physiological measurements and mutants deficient in abscisic acid, salicylic acid, jasmonic acid or ethylene signaling. Arabidopsis plants were found to be more susceptible to a combination of salt and heat stress compared to each of the different stresses applied individually. The stress combination resulted in a higher ratio of Na+/K+ in leaves and caused the enhanced expression of 699 transcripts unique to the stress combination. Interestingly, many of the transcripts that specifically accumulated in plants in response to the salt and heat stress combination were associated with the plant hormone abscisic acid. In accordance with this finding, mutants deficient in abscisic acid metabolism and signaling were found to be more susceptible to a combination of salt and heat stress than wild type plants. Our study highlights the important role abscisic acid plays in the acclimation of plants to a combination of two different abiotic stresses.

ABA Is Required for Plant Acclimation to a Combination of Salt and Heat Stress

PubMed Central

Suzuki, Nobuhiro; Bassil, Elias; Hamilton, Jason S.; Inupakutika, Madhuri A.; Zandalinas, Sara Izquierdo; Tripathy, Deesha; Luo, Yuting; Dion, Erin; Fukui, Ginga; Kumazaki, Ayana; Nakano, Ruka; Rivero, Rosa M.; Verbeck, Guido F.; Azad, Rajeev K.; Blumwald, Eduardo; Mittler, Ron

2016-01-01

Abiotic stresses such as drought, heat or salinity are a major cause of yield loss worldwide. Recent studies revealed that the acclimation of plants to a combination of different environmental stresses is unique and cannot be directly deduced from studying the response of plants to each of the different stresses applied individually. Here we report on the response of Arabidopsis thaliana to a combination of salt and heat stress using transcriptome analysis, physiological measurements and mutants deficient in abscisic acid, salicylic acid, jasmonic acid or ethylene signaling. Arabidopsis plants were found to be more susceptible to a combination of salt and heat stress compared to each of the different stresses applied individually. The stress combination resulted in a higher ratio of Na+/K+ in leaves and caused the enhanced expression of 699 transcripts unique to the stress combination. Interestingly, many of the transcripts that specifically accumulated in plants in response to the salt and heat stress combination were associated with the plant hormone abscisic acid. In accordance with this finding, mutants deficient in abscisic acid metabolism and signaling were found to be more susceptible to a combination of salt and heat stress than wild type plants. Our study highlights the important role abscisic acid plays in the acclimation of plants to a combination of two different abiotic stresses. PMID:26824246

Transcriptomic analysis on the formation of the viable putative non-culturable state of beer-spoilage Lactobacillus acetotolerans

PubMed Central

Liu, Junyan; Deng, Yang; Peters, Brian M.; Li, Lin; Li, Bing; Chen, Lequn; Xu, Zhenbo; Shirtliff, Mark E.

2016-01-01

Lactic acid bacteria (LAB) are the most common beer-spoilage bacteria regardless of beer type, and thus pose significant problems for the brewery industry. The aim of this study was to investigate the genetic mechanisms involved in the ability of the hard-to-culture beer-spoilage bacterium Lactobacillus acetotolerans to enter into the viable putative non-culturable (VPNC) state. A genome-wide transcriptional analysis of beer-spoilage L. acetotolerans strains BM-LA14526, BM-LA14527, and BM-LA14528 under normal, mid-term and VPNC states were performed using RNA-sequencing (RNA-seq) and further bioinformatics analyses. GO function, COG category, and KEGG pathway enrichment analysis were conducted to investigate functional and related metabolic pathways of the differentially expressed genes. Functional and pathway enrichment analysis indicated that heightened stress response and reduction in genes associated with transport, metabolic process, and enzyme activity might play important roles in the formation of the VPNC state. This is the first transcriptomic analysis on the formation of the VPNC state of beer spoilage L. acetotolerans. PMID:27819317

Transcriptomic analysis on the formation of the viable putative non-culturable state of beer-spoilage Lactobacillus acetotolerans.

PubMed

Liu, Junyan; Deng, Yang; Peters, Brian M; Li, Lin; Li, Bing; Chen, Lequn; Xu, Zhenbo; Shirtliff, Mark E

2016-11-07

Lactic acid bacteria (LAB) are the most common beer-spoilage bacteria regardless of beer type, and thus pose significant problems for the brewery industry. The aim of this study was to investigate the genetic mechanisms involved in the ability of the hard-to-culture beer-spoilage bacterium Lactobacillus acetotolerans to enter into the viable putative non-culturable (VPNC) state. A genome-wide transcriptional analysis of beer-spoilage L. acetotolerans strains BM-LA14526, BM-LA14527, and BM-LA14528 under normal, mid-term and VPNC states were performed using RNA-sequencing (RNA-seq) and further bioinformatics analyses. GO function, COG category, and KEGG pathway enrichment analysis were conducted to investigate functional and related metabolic pathways of the differentially expressed genes. Functional and pathway enrichment analysis indicated that heightened stress response and reduction in genes associated with transport, metabolic process, and enzyme activity might play important roles in the formation of the VPNC state. This is the first transcriptomic analysis on the formation of the VPNC state of beer spoilage L. acetotolerans.

Exposure to Solute Stress Affects Genome-Wide Expression but Not the Polycyclic Aromatic Hydrocarbon-Degrading Activity of Sphingomonas sp. Strain LH128 in Biofilms

PubMed Central

Fida, Tekle Tafese; Breugelmans, Philip; Lavigne, Rob; Coronado, Edith; Johnson, David R.; van der Meer, Jan Roelof; Mayer, Antonia P.; Heipieper, Hermann J.; Hofkens, Johan

2012-01-01

Members of the genus Sphingomonas are important catalysts for removal of polycyclic aromatic hydrocarbons (PAHs) in soil, but their activity can be affected by various stress factors. This study examines the physiological and genome-wide transcription response of the phenanthrene-degrading Sphingomonas sp. strain LH128 in biofilms to solute stress (invoked by 450 mM NaCl solution), either as an acute (4-h) or a chronic (3-day) exposure. The degree of membrane fatty acid saturation was increased as a response to chronic stress. Oxygen consumption in the biofilms and phenanthrene mineralization activities of biofilm cells were, however, not significantly affected after imposing either acute or chronic stress. This finding was in agreement with the transcriptomic data, since genes involved in PAH degradation were not differentially expressed in stressed conditions compared to nonstressed conditions. The transcriptomic data suggest that LH128 adapts to NaCl stress by (i) increasing the expression of genes coping with osmolytic and ionic stress such as biosynthesis of compatible solutes and regulation of ion homeostasis, (ii) increasing the expression of genes involved in general stress response, (iii) changing the expression of general and specific regulatory functions, and (iv) decreasing the expression of protein synthesis such as proteins involved in motility. Differences in gene expression between cells under acute and chronic stress suggest that LH128 goes through changes in genome-wide expression to fully adapt to NaCl stress, without significantly changing phenanthrene degrading activity. PMID:23001650

Rapid Acclimation Ability Mediated by Transcriptome Changes in Reef-Building Corals

PubMed Central

Bay, Rachael A.; Palumbi, Stephen R.

2015-01-01

Population response to environmental variation involves adaptation, acclimation, or both. For long-lived organisms, acclimation likely generates a faster response but is only effective if the rates and limits of acclimation match the dynamics of local environmental variation. In coral reef habitats, heat stress from extreme ocean warming can occur over several weeks, resulting in symbiont expulsion and widespread coral death. However, transcriptome regulation during short-term acclimation is not well understood. We examined acclimation during a 11-day experiment in the coral Acropora nana. We acclimated colonies to three regimes: ambient temperature (29 °C), increased stable temperature (31 °C), and variable temperature (29–33 °C), mimicking local heat stress conditions. Within 7–11 days, individuals acclimated to increased temperatures had higher tolerance to acute heat stress. Despite physiological changes, no gene expression changes occurred during acclimation before acute heat stress. However, we found strikingly different transcriptional responses to heat stress between acclimation treatments across 893 contigs. Across these contigs, corals acclimated to higher temperatures (31 °C or 29–33 °C) exhibited a muted stress response—the magnitude of expression change before and after heat stress was less than in 29 °C acclimated corals. Our results show that corals have a rapid phase of acclimation that substantially increases their heat resilience within 7 days and that alters their transcriptional response to heat stress. This is in addition to a previously observed longer term response, distinguishable by its shift in baseline expression, under nonstressful conditions. Such rapid acclimation may provide some protection for this species of coral against slow onset of warming ocean temperatures. PMID:25979751

Global Analysis of Gene Expression Profiles in Physic Nut (Jatropha curcas L.) Seedlings Exposed to Salt Stress

PubMed Central

Wu, Pingzhi; Chen, Yaping; Li, Meiru; Jiang, Huawu; Wu, Guojiang

2014-01-01

Background Salt stress interferes with plant growth and production. Plants have evolved a series of molecular and morphological adaptations to cope with this abiotic stress, and overexpression of salt response genes reportedly enhances the productivity of various crops. However, little is known about the salt responsive genes in the energy plant physic nut (Jatropha curcas L.). Thus, excavate salt responsive genes in this plant are informative in uncovering the molecular mechanisms for the salt response in physic nut. Methodology/Principal Findings We applied next-generation Illumina sequencing technology to analyze global gene expression profiles of physic nut plants (roots and leaves) 2 hours, 2 days and 7 days after the onset of salt stress. A total of 1,504 and 1,115 genes were significantly up and down-regulated in roots and leaves, respectively, under salt stress condition. Gene ontology (GO) analysis of physiological process revealed that, in the physic nut, many “biological processes” were affected by salt stress, particular those categories belong to “metabolic process”, such as “primary metabolism process”, “cellular metabolism process” and “macromolecule metabolism process”. The gene expression profiles indicated that the associated genes were responsible for ABA and ethylene signaling, osmotic regulation, the reactive oxygen species scavenging system and the cell structure in physic nut. Conclusions/Significance The major regulated genes detected in this transcriptomic data were related to trehalose synthesis and cell wall structure modification in roots, while related to raffinose synthesis and reactive oxygen scavenger in leaves. The current study shows a comprehensive gene expression profile of physic nut under salt stress. The differential expression genes detected in this study allows the underling the salt responsive mechanism in physic nut with the aim of improving its salt resistance in the future. PMID:24837971

Global analysis of gene expression profiles in physic nut (Jatropha curcas L.) seedlings exposed to salt stress.

PubMed

Zhang, Lin; Zhang, Chao; Wu, Pingzhi; Chen, Yaping; Li, Meiru; Jiang, Huawu; Wu, Guojiang

2014-01-01

Salt stress interferes with plant growth and production. Plants have evolved a series of molecular and morphological adaptations to cope with this abiotic stress, and overexpression of salt response genes reportedly enhances the productivity of various crops. However, little is known about the salt responsive genes in the energy plant physic nut (Jatropha curcas L.). Thus, excavate salt responsive genes in this plant are informative in uncovering the molecular mechanisms for the salt response in physic nut. We applied next-generation Illumina sequencing technology to analyze global gene expression profiles of physic nut plants (roots and leaves) 2 hours, 2 days and 7 days after the onset of salt stress. A total of 1,504 and 1,115 genes were significantly up and down-regulated in roots and leaves, respectively, under salt stress condition. Gene ontology (GO) analysis of physiological process revealed that, in the physic nut, many "biological processes" were affected by salt stress, particular those categories belong to "metabolic process", such as "primary metabolism process", "cellular metabolism process" and "macromolecule metabolism process". The gene expression profiles indicated that the associated genes were responsible for ABA and ethylene signaling, osmotic regulation, the reactive oxygen species scavenging system and the cell structure in physic nut. The major regulated genes detected in this transcriptomic data were related to trehalose synthesis and cell wall structure modification in roots, while related to raffinose synthesis and reactive oxygen scavenger in leaves. The current study shows a comprehensive gene expression profile of physic nut under salt stress. The differential expression genes detected in this study allows the underling the salt responsive mechanism in physic nut with the aim of improving its salt resistance in the future.

Transcriptome-wide identification and expression profiles of the WRKY transcription factor family in Broomcorn millet (Panicum miliaceum L.).

PubMed

Yue, Hong; Wang, Meng; Liu, Siyan; Du, Xianghong; Song, Weining; Nie, Xiaojun

2016-05-10

WRKY genes, as the most pivotal transcription factors in plants, play the indispensable roles in regulating various physiological processes, including plant growth and development as well as in response to stresses. Broomcorn millet is one of the most important crops in drought areas worldwide. However, the WRKY gene family in broomcorn millet remains unknown. A total of 32 PmWRKY genes were identified in this study using computational prediction method. Structural analysis found that PmWRKY proteins contained a highly conserved motif WRKYGQK and two common variant motifs, namely WRKYGKK and WRKYGEK. Phylogenetic analysis of PmWRKYs together with the homologous genes from the representative species could classify them into three groups, with the number of 1, 15, and 16, respectively. Finally, the transcriptional profiles of these 32 PmWRKY genes in various tissues or under different abiotic stresses were systematically investigated using qRT-PCR analysis. Results showed that the expression level of 22 PmWRKY genes varied significantly under one or more abiotic stress treatments, which could be defined as abiotic stress-responsive genes. This was the first study to identify the organization and transcriptional profiles of PmWRKY genes, which not only facilitates the functional analysis of the PmWRKY genes, and also lays the foundation to reveal the molecular mechanism of stress tolerance in this important crop.

A Transcriptome Meta-Analysis Proposes Novel Biological Roles for the Antifungal Protein AnAFP in Aspergillus niger

PubMed Central

Schäpe, Paul; Müller-Hagen, Dirk; Ouedraogo, Jean-Paul; Heiderich, Caroline; Jedamzick, Johanna; van den Hondel, Cees A.; Ram, Arthur F.; Meyer, Vera

2016-01-01

Understanding the genetic, molecular and evolutionary basis of cysteine-stabilized antifungal proteins (AFPs) from fungi is important for understanding whether their function is mainly defensive or associated with fungal growth and development. In the current study, a transcriptome meta-analysis of the Aspergillus niger γ-core protein AnAFP was performed to explore co-expressed genes and pathways, based on independent expression profiling microarrays covering 155 distinct cultivation conditions. This analysis uncovered that anafp displays a highly coordinated temporal and spatial transcriptional profile which is concomitant with key nutritional and developmental processes. Its expression profile coincides with early starvation response and parallels with genes involved in nutrient mobilization and autophagy. Using fluorescence- and luciferase reporter strains we demonstrated that the anafp promoter is active in highly vacuolated compartments and foraging hyphal cells during carbon starvation with CreA and FlbA, but not BrlA, as most likely regulators of anafp. A co-expression network analysis supported by luciferase-based reporter assays uncovered that anafp expression is embedded in several cellular processes including allorecognition, osmotic and oxidative stress survival, development, secondary metabolism and autophagy, and predicted StuA and VelC as additional regulators. The transcriptomic resources available for A. niger provide unparalleled resources to investigate the function of proteins. Our work illustrates how transcriptomic meta-analyses can lead to hypotheses regarding protein function and predict a role for AnAFP during slow growth, allorecognition, asexual development and nutrient recycling of A. niger and propose that it interacts with the autophagic machinery to enable these processes. PMID:27835655

A Transcriptome Meta-Analysis Proposes Novel Biological Roles for the Antifungal Protein AnAFP in Aspergillus niger.

PubMed

Paege, Norman; Jung, Sascha; Schäpe, Paul; Müller-Hagen, Dirk; Ouedraogo, Jean-Paul; Heiderich, Caroline; Jedamzick, Johanna; Nitsche, Benjamin M; van den Hondel, Cees A; Ram, Arthur F; Meyer, Vera

2016-01-01

Understanding the genetic, molecular and evolutionary basis of cysteine-stabilized antifungal proteins (AFPs) from fungi is important for understanding whether their function is mainly defensive or associated with fungal growth and development. In the current study, a transcriptome meta-analysis of the Aspergillus niger γ-core protein AnAFP was performed to explore co-expressed genes and pathways, based on independent expression profiling microarrays covering 155 distinct cultivation conditions. This analysis uncovered that anafp displays a highly coordinated temporal and spatial transcriptional profile which is concomitant with key nutritional and developmental processes. Its expression profile coincides with early starvation response and parallels with genes involved in nutrient mobilization and autophagy. Using fluorescence- and luciferase reporter strains we demonstrated that the anafp promoter is active in highly vacuolated compartments and foraging hyphal cells during carbon starvation with CreA and FlbA, but not BrlA, as most likely regulators of anafp. A co-expression network analysis supported by luciferase-based reporter assays uncovered that anafp expression is embedded in several cellular processes including allorecognition, osmotic and oxidative stress survival, development, secondary metabolism and autophagy, and predicted StuA and VelC as additional regulators. The transcriptomic resources available for A. niger provide unparalleled resources to investigate the function of proteins. Our work illustrates how transcriptomic meta-analyses can lead to hypotheses regarding protein function and predict a role for AnAFP during slow growth, allorecognition, asexual development and nutrient recycling of A. niger and propose that it interacts with the autophagic machinery to enable these processes.

De novo RNA-Seq based transcriptome analysis of Papiliotrema laurentii strain RY1 under nitrogen starvation.

PubMed

Sarkar, Soumyadev; Chakravorty, Somnath; Mukherjee, Avishek; Bhattacharya, Debanjana; Bhattacharya, Semantee; Gachhui, Ratan

2018-03-01

Nitrogen is a key nutrient for all cell forms. Most organisms respond to nitrogen scarcity by slowing down their growth rate. On the contrary, our previous studies have shown that Papiliotrema laurentii strain RY1 has a robust growth under nitrogen starvation. To understand the global regulation that leads to such an extraordinary response, we undertook a de novo approach for transcriptome analysis of the yeast. Close to 33 million sequence reads of high quality for nitrogen limited and enriched condition were generated using Illumina NextSeq500. Trinity analysis and clustered transcripts annotation of the reads produced 17,611 unigenes, out of which 14,157 could be annotated. Gene Ontology term analysis generated 44.92% cellular component terms, 39.81% molecular function terms and 15.24% biological process terms. The most over represented pathways in general were translation, carbohydrate metabolism, amino acid metabolism, general metabolism, folding, sorting, degradation followed by transport and catabolism, nucleotide metabolism, replication and repair, transcription and lipid metabolism. A total of 4256 Single Sequence Repeats were identified. Differential gene expression analysis detected 996 P-significant transcripts to reveal transmembrane transport, lipid homeostasis, fatty acid catabolism and translation as the enriched terms which could be essential for Papiliotrema laurentii strain RY1 to adapt during nitrogen deprivation. Transcriptome data was validated by quantitative real-time PCR analysis of twelve transcripts. To the best of our knowledge, this is the first report of Papiliotrema laurentii strain RY1 transcriptome which would play a pivotal role in understanding the biochemistry of the yeast under acute nitrogen stress and this study would be encouraging to initiate extensive investigations into this Papiliotrema system. Copyright © 2017 Elsevier B.V. All rights reserved.

Isolation of polysomal RNA for analyzing stress-responsive genes regulated at the translational level in plants

USDA-ARS?s Scientific Manuscript database

Alteration of gene expression is an essential mechanism, which allows plants to respond and adapt to adverse environmental conditions. Transcriptome and proteome analyses in plants exposed to abiotic stresses revealed that protein levels are not correlated with the changes in corresponding mRNAs, in...

Physiology and transcriptomics of water-deficit stress responses in wheat cultivars TAM 111 and TAM 112

USDA-ARS?s Scientific Manuscript database

Hard red winter wheat crops on the U.S. Southern Great Plains often experience moderate to severe drought stress, especially during the grain filling stage, resulting in significant yield losses. Among popular commercial varieties, TAM 111 and TAM 112 showed a superior adaptation to water-deficit c...

Shape-Shifted Red Blood Cells: A Novel Red Blood Cell Stage?

PubMed Central

Chico, Verónica; Puente-Marin, Sara; Ciordia, Sergio; Mena, María Carmen; Carracedo, Begoña; Mercado, Luis; Coll, Julio

2018-01-01

Primitive nucleated erythroid cells in the bloodstream have long been suggested to be more similar to nucleated red cells of fish, amphibians, and birds than the red cells of fetal and adult mammals. Rainbow trout Ficoll-purified red blood cells (RBCs) cultured in vitro undergo morphological changes, especially when exposed to stress, and enter a new cell stage that we have coined shape-shifted RBCs (shRBCs). We have characterized these shRBCs using transmission electron microscopy (TEM) micrographs, Wright–Giemsa staining, cell marker immunostaining, and transcriptomic and proteomic evaluation. shRBCs showed reduced density of the cytoplasm, hemoglobin loss, decondensed chromatin in the nucleus, and striking expression of the B lymphocyte molecular marker IgM. In addition, shRBCs shared some features of mammalian primitive pyrenocytes (extruded nucleus surrounded by a thin rim of cytoplasm and phosphatidylserine (PS) exposure on cell surface). These shRBCs were transiently observed in heat-stressed rainbow trout bloodstream for three days. Functional network analysis of combined transcriptomic and proteomic studies resulted in the identification of proteins involved in pathways related to the regulation of cell morphogenesis involved in differentiation, cellular response to stress, and immune system process. In addition, shRBCs increased interleukin 8 (IL8), interleukin 1 β (IL1β), interferon ɣ (IFNɣ), and natural killer enhancing factor (NKEF) protein production in response to viral hemorrhagic septicemia virus (VHSV). In conclusion, shRBCs may represent a novel cell stage that participates in roles related to immune response mediation, homeostasis, and the differentiation and development of blood cells. PMID:29671811

Shape-Shifted Red Blood Cells: A Novel Red Blood Cell Stage?

PubMed

Chico, Verónica; Puente-Marin, Sara; Nombela, Iván; Ciordia, Sergio; Mena, María Carmen; Carracedo, Begoña; Villena, Alberto; Mercado, Luis; Coll, Julio; Ortega-Villaizan, María Del Mar

2018-04-19

Primitive nucleated erythroid cells in the bloodstream have long been suggested to be more similar to nucleated red cells of fish, amphibians, and birds than the red cells of fetal and adult mammals. Rainbow trout Ficoll-purified red blood cells (RBCs) cultured in vitro undergo morphological changes, especially when exposed to stress, and enter a new cell stage that we have coined shape-shifted RBCs (shRBCs). We have characterized these shRBCs using transmission electron microscopy (TEM) micrographs, Wright⁻Giemsa staining, cell marker immunostaining, and transcriptomic and proteomic evaluation. shRBCs showed reduced density of the cytoplasm, hemoglobin loss, decondensed chromatin in the nucleus, and striking expression of the B lymphocyte molecular marker IgM. In addition, shRBCs shared some features of mammalian primitive pyrenocytes (extruded nucleus surrounded by a thin rim of cytoplasm and phosphatidylserine (PS) exposure on cell surface). These shRBCs were transiently observed in heat-stressed rainbow trout bloodstream for three days. Functional network analysis of combined transcriptomic and proteomic studies resulted in the identification of proteins involved in pathways related to the regulation of cell morphogenesis involved in differentiation, cellular response to stress, and immune system process. In addition, shRBCs increased interleukin 8 (IL8), interleukin 1 β (IL1β), interferon ɣ (IFNɣ), and natural killer enhancing factor (NKEF) protein production in response to viral hemorrhagic septicemia virus (VHSV). In conclusion, shRBCs may represent a novel cell stage that participates in roles related to immune response mediation, homeostasis, and the differentiation and development of blood cells.

Transcriptional Profiling and Identification of Heat-Responsive Genes in Perennial Ryegrass by RNA-Sequencing

PubMed Central

Wang, Kehua; Liu, Yanrong; Tian, Jinli; Huang, Kunyong; Shi, Tianran; Dai, Xiaoxia; Zhang, Wanjun

2017-01-01

Perennial ryegrass (Lolium perenne) is one of the most widely used forage and turf grasses in the world due to its desirable agronomic qualities. However, as a cool-season perennial grass species, high temperature is a major factor limiting its performance in warmer and transition regions. In this study, a de novo transcriptome was generated using a cDNA library constructed from perennial ryegrass leaves subjected to short-term heat stress treatment. Then the expression profiling and identification of perennial ryegrass heat response genes by digital gene expression analyses was performed. The goal of this work was to produce expression profiles of high temperature stress responsive genes in perennial ryegrass leaves and further identify the potentially important candidate genes with altered levels of transcript, such as those genes involved in transcriptional regulation, antioxidant responses, plant hormones and signal transduction, and cellular metabolism. The de novo assembly of perennial ryegrass transcriptome in this study obtained more total and annotated unigenes compared to previously published ones. Many DEGs identified were genes that are known to respond to heat stress in plants, including HSFs, HSPs, and antioxidant related genes. In the meanwhile, we also identified four gene candidates mainly involved in C4 carbon fixation, and one TOR gene. Their exact roles in plant heat stress response need to dissect further. This study would be important by providing the gene resources for improving heat stress tolerance in both perennial ryegrass and other cool-season perennial grass plants. PMID:28680431

Global Transcriptional, Physiological, and Metabolite Analyses of the Responses of Desulfovibrio vulgaris Hildenborough to Salt Adaptation ▿ †

PubMed Central

He, Zhili; Zhou, Aifen; Baidoo, Edward; He, Qiang; Joachimiak, Marcin P.; Benke, Peter; Phan, Richard; Mukhopadhyay, Aindrila; Hemme, Christopher L.; Huang, Katherine; Alm, Eric J.; Fields, Matthew W.; Wall, Judy; Stahl, David; Hazen, Terry C.; Keasling, Jay D.; Arkin, Adam P.; Zhou, Jizhong

2010-01-01

The response of Desulfovibrio vulgaris Hildenborough to salt adaptation (long-term NaCl exposure) was examined by performing physiological, global transcriptional, and metabolite analyses. Salt adaptation was reflected by increased expression of genes involved in amino acid biosynthesis and transport, electron transfer, hydrogen oxidation, and general stress responses (e.g., heat shock proteins, phage shock proteins, and oxidative stress response proteins). The expression of genes involved in carbon metabolism, cell growth, and phage structures was decreased. Transcriptome profiles of D. vulgaris responses to salt adaptation were compared with transcriptome profiles of D. vulgaris responses to salt shock (short-term NaCl exposure). Metabolite assays showed that glutamate and alanine accumulated under salt adaptation conditions, suggesting that these amino acids may be used as osmoprotectants in D. vulgaris. Addition of amino acids (glutamate, alanine, and tryptophan) or yeast extract to the growth medium relieved salt-related growth inhibition. A conceptual model that links the observed results to currently available knowledge is proposed to increase our understanding of the mechanisms of D. vulgaris adaptation to elevated NaCl levels. PMID:20038696

Transcriptome analysis of salinity stress responses in common wheat using a 22k oligo-DNA microarray.

PubMed

Kawaura, Kanako; Mochida, Keiichi; Yamazaki, Yukiko; Ogihara, Yasunari

2006-04-01

In this study, we constructed a 22k wheat oligo-DNA microarray. A total of 148,676 expressed sequence tags of common wheat were collected from the database of the Wheat Genomics Consortium of Japan. These were grouped into 34,064 contigs, which were then used to design an oligonucleotide DNA microarray. Following a multistep selection of the sense strand, 21,939 60-mer oligo-DNA probes were selected for attachment on the microarray slide. This 22k oligo-DNA microarray was used to examine the transcriptional response of wheat to salt stress. More than 95% of the probes gave reproducible hybridization signals when targeted with RNAs extracted from salt-treated wheat shoots and roots. With the microarray, we identified 1,811 genes whose expressions changed more than 2-fold in response to salt. These included genes known to mediate response to salt, as well as unknown genes, and they were classified into 12 major groups by hierarchical clustering. These gene expression patterns were also confirmed by real-time reverse transcription-PCR. Many of the genes with unknown function were clustered together with genes known to be involved in response to salt stress. Thus, analysis of gene expression patterns combined with gene ontology should help identify the function of the unknown genes. Also, functional analysis of these wheat genes should provide new insight into the response to salt stress. Finally, these results indicate that the 22k oligo-DNA microarray is a reliable method for monitoring global gene expression patterns in wheat.

Transcriptome profiles link environmental variation and physiological response of Mytilus californianus between Pacific tides

PubMed Central

Place, Sean P.; Menge, Bruce A.; Hofmann, Gretchen E.

2011-01-01

Summary The marine intertidal zone is characterized by large variation in temperature, pH, dissolved oxygen and the supply of nutrients and food on seasonal and daily time scales. These oceanic fluctuations drive of ecological processes such as recruitment, competition and consumer-prey interactions largely via physiological mehcanisms. Thus, to understand coastal ecosystem dynamics and responses to climate change, it is crucial to understand these mechanisms. Here we utilize transcriptome analysis of the physiological response of the mussel Mytilus californianus at different spatial scales to gain insight into these mechanisms. We used mussels inhabiting different vertical locations within Strawberry Hill on Cape Perpetua, OR and Boiler Bay on Cape Foulweather, OR to study inter- and intra-site variation of gene expression. The results highlight two distinct gene expression signatures related to the cycling of metabolic activity and perturbations to cellular homeostasis. Intermediate spatial scales show a strong influence of oceanographic differences in food and stress environments between sites separated by ~65 km. Together, these new insights into environmental control of gene expression may allow understanding of important physiological drivers within and across populations. PMID:22563136

Transcriptome Response Mediated by Cold Stress in Lotus japonicus.

PubMed

Calzadilla, Pablo I; Maiale, Santiago J; Ruiz, Oscar A; Escaray, Francisco J

2016-01-01

Members of the Lotus genus are important as agricultural forage sources under marginal environmental conditions given their high nutritional value and tolerance of various abiotic stresses. However, their dry matter production is drastically reduced in cooler seasons, while their response to such conditions is not well studied. This paper analyzes cold acclimation of the genus by studying Lotus japonicus over a stress period of 24 h. High-throughput RNA sequencing was used to identify and classify 1077 differentially expressed genes, of which 713 were up-regulated and 364 were down-regulated. Up-regulated genes were principally related to lipid, cell wall, phenylpropanoid, sugar, and proline regulation, while down-regulated genes affected the photosynthetic process and chloroplast development. Together, a total of 41 cold-inducible transcription factors were identified, including members of the AP2/ERF, NAC, MYB, and WRKY families; two of them were described as putative novel transcription factors. Finally, DREB1/CBFs were described with respect to their cold stress expression profiles. This is the first transcriptome profiling of the model legume L. japonicus under cold stress. Data obtained may be useful in identifying candidate genes for breeding modified species of forage legumes that more readily acclimate to low temperatures.

Mechanism of cisplatin proximal tubule toxicity revealed by integrating transcriptomics, proteomics, metabolomics and biokinetics.

PubMed

Wilmes, Anja; Bielow, Chris; Ranninger, Christina; Bellwon, Patricia; Aschauer, Lydia; Limonciel, Alice; Chassaigne, Hubert; Kristl, Theresa; Aiche, Stephan; Huber, Christian G; Guillou, Claude; Hewitt, Philipp; Leonard, Martin O; Dekant, Wolfgang; Bois, Frederic; Jennings, Paul

2015-12-25

Cisplatin is one of the most widely used chemotherapeutic agents for the treatment of solid tumours. The major dose-limiting factor is nephrotoxicity, in particular in the proximal tubule. Here, we use an integrated omics approach, including transcriptomics, proteomics and metabolomics coupled to biokinetics to identify cell stress response pathways induced by cisplatin. The human renal proximal tubular cell line RPTEC/TERT1 was treated with sub-cytotoxic concentrations of cisplatin (0.5 and 2 μM) in a daily repeat dose treating regime for up to 14 days. Biokinetic analysis showed that cisplatin was taken up from the basolateral compartment, transported to the apical compartment, and accumulated in cells over time. This is in line with basolateral uptake of cisplatin via organic cation transporter 2 and bioactivation via gamma-glutamyl transpeptidase located on the apical side of proximal tubular cells. Cisplatin affected several pathways including, p53 signalling, Nrf2 mediated oxidative stress response, mitochondrial processes, mTOR and AMPK signalling. In addition, we identified novel pathways changed by cisplatin, including eIF2 signalling, actin nucleation via the ARP/WASP complex and regulation of cell polarization. In conclusion, using an integrated omic approach together with biokinetics we have identified both novel and established mechanisms of cisplatin toxicity. Copyright © 2014 Elsevier Ltd. All rights reserved.

Transcripts and MicroRNAs Responding to Salt Stress in Musa acuminata Colla (AAA Group) cv. Berangan Roots

PubMed Central

Lee, Wan Sin; Gudimella, Ranganath; Wong, Gwo Rong; Tammi, Martti Tapani; Khalid, Norzulaani; Harikrishna, Jennifer Ann

2015-01-01

Physiological responses to stress are controlled by expression of a large number of genes, many of which are regulated by microRNAs. Since most banana cultivars are salt-sensitive, improved understanding of genetic regulation of salt induced stress responses in banana can support future crop management and improvement in the face of increasing soil salinity related to irrigation and climate change. In this study we focused on determining miRNA and their targets that respond to NaCl exposure and used transcriptome sequencing of RNA and small RNA from control and NaCl-treated banana roots to assemble a cultivar-specific reference transcriptome and identify orthologous and Musa-specific miRNA responding to salinity. We observed that, banana roots responded to salinity stress with changes in expression for a large number of genes (9.5% of 31,390 expressed unigenes) and reduction in levels of many miRNA, including several novel miRNA and banana-specific miRNA-target pairs. Banana roots expressed a unique set of orthologous and Musa-specific miRNAs of which 59 respond to salt stress in a dose-dependent manner. Gene expression patterns of miRNA compared with those of their predicted mRNA targets indicated that a majority of the differentially expressed miRNAs were down-regulated in response to increased salinity, allowing increased expression of targets involved in diverse biological processes including stress signaling, stress defence, transport, cellular homeostasis, metabolism and other stress-related functions. This study may contribute to the understanding of gene regulation and abiotic stress response of roots and the high-throughput sequencing data sets generated may serve as important resources related to salt tolerance traits for functional genomic studies and genetic improvement in banana. PMID:25993649

Transcripts and MicroRNAs Responding to Salt Stress in Musa acuminata Colla (AAA Group) cv. Berangan Roots.

PubMed

Lee, Wan Sin; Gudimella, Ranganath; Wong, Gwo Rong; Tammi, Martti Tapani; Khalid, Norzulaani; Harikrishna, Jennifer Ann

2015-01-01

Physiological responses to stress are controlled by expression of a large number of genes, many of which are regulated by microRNAs. Since most banana cultivars are salt-sensitive, improved understanding of genetic regulation of salt induced stress responses in banana can support future crop management and improvement in the face of increasing soil salinity related to irrigation and climate change. In this study we focused on determining miRNA and their targets that respond to NaCl exposure and used transcriptome sequencing of RNA and small RNA from control and NaCl-treated banana roots to assemble a cultivar-specific reference transcriptome and identify orthologous and Musa-specific miRNA responding to salinity. We observed that, banana roots responded to salinity stress with changes in expression for a large number of genes (9.5% of 31,390 expressed unigenes) and reduction in levels of many miRNA, including several novel miRNA and banana-specific miRNA-target pairs. Banana roots expressed a unique set of orthologous and Musa-specific miRNAs of which 59 respond to salt stress in a dose-dependent manner. Gene expression patterns of miRNA compared with those of their predicted mRNA targets indicated that a majority of the differentially expressed miRNAs were down-regulated in response to increased salinity, allowing increased expression of targets involved in diverse biological processes including stress signaling, stress defence, transport, cellular homeostasis, metabolism and other stress-related functions. This study may contribute to the understanding of gene regulation and abiotic stress response of roots and the high-throughput sequencing data sets generated may serve as important resources related to salt tolerance traits for functional genomic studies and genetic improvement in banana.

Systems and Trans-System Level Analysis Identifies Conserved Iron Deficiency Responses in the Plant Lineage[W][OA

PubMed Central

Urzica, Eugen I.; Casero, David; Yamasaki, Hiroaki; Hsieh, Scott I.; Adler, Lital N.; Karpowicz, Steven J.; Blaby-Haas, Crysten E.; Clarke, Steven G.; Loo, Joseph A.; Pellegrini, Matteo; Merchant, Sabeeha S.

2012-01-01

We surveyed the iron nutrition-responsive transcriptome of Chlamydomonas reinhardtii using RNA-Seq methodology. Presumed primary targets were identified in comparisons between visually asymptomatic iron-deficient versus iron-replete cells. This includes the known components of high-affinity iron uptake as well as candidates for distributive iron transport in C. reinhardtii. Comparison of growth-inhibited iron-limited versus iron-replete cells revealed changes in the expression of genes in chloroplastic oxidative stress response pathways, among hundreds of other genes. The output from the transcriptome was validated at multiple levels: by quantitative RT-PCR for assessing the data analysis pipeline, by quantitative proteomics for assessing the impact of changes in RNA abundance on the proteome, and by cross-species comparison for identifying conserved or universal response pathways. In addition, we assessed the functional importance of three target genes, VITAMIN C 2 (VTC2), MONODEHYDROASCORBATE REDUCTASE 1 (MDAR1), and CONSERVED IN THE GREEN LINEAGE AND DIATOMS 27 (CGLD27), by biochemistry or reverse genetics. VTC2 and MDAR1, which are key enzymes in de novo ascorbate synthesis and ascorbate recycling, respectively, are likely responsible for the 10-fold increase in ascorbate content of iron-limited cells. CGLD27/At5g67370 is a highly conserved, presumed chloroplast-localized pioneer protein and is important for growth of Arabidopsis thaliana in low iron. PMID:23043051

Genome-wide gene phylogeny of CIPK family in cassava and expression analysis of partial drought-induced genes

PubMed Central

Hu, Wei; Xia, Zhiqiang; Yan, Yan; Ding, Zehong; Tie, Weiwei; Wang, Lianzhe; Zou, Meiling; Wei, Yunxie; Lu, Cheng; Hou, Xiaowan; Wang, Wenquan; Peng, Ming

2015-01-01

Cassava is an important food and potential biofuel crop that is tolerant to multiple abiotic stressors. The mechanisms underlying these tolerances are currently less known. CBL-interacting protein kinases (CIPKs) have been shown to play crucial roles in plant developmental processes, hormone signaling transduction, and in the response to abiotic stress. However, no data is currently available about the CPK family in cassava. In this study, a total of 25 CIPK genes were identified from cassava genome based on our previous genome sequencing data. Phylogenetic analysis suggested that 25 MeCIPKs could be classified into four subfamilies, which was supported by exon-intron organizations and the architectures of conserved protein motifs. Transcriptomic analysis of a wild subspecies and two cultivated varieties showed that most MeCIPKs had different expression patterns between wild subspecies and cultivatars in different tissues or in response to drought stress. Some orthologous genes involved in CIPK interaction networks were identified between Arabidopsis and cassava. The interaction networks and co-expression patterns of these orthologous genes revealed that the crucial pathways controlled by CIPK networks may be involved in the differential response to drought stress in different accessions of cassava. Nine MeCIPK genes were selected to investigate their transcriptional response to various stimuli and the results showed the comprehensive response of the tested MeCIPK genes to osmotic, salt, cold, oxidative stressors, and ABA signaling. The identification and expression analysis of CIPK family suggested that CIPK genes are important components of development and multiple signal transduction pathways in cassava. The findings of this study will help lay a foundation for the functional characterization of the CIPK gene family and provide an improved understanding of abiotic stress responses and signaling transduction in cassava. PMID:26579161

Heat Shock Response in Yeast Involves Changes in Both Transcription Rates and mRNA Stabilities

PubMed Central

Castells-Roca, Laia; García-Martínez, José; Moreno, Joaquín; Herrero, Enrique; Bellí, Gemma; Pérez-Ortín, José E.

2011-01-01

We have analyzed the heat stress response in the yeast Saccharomyces cerevisiae by determining mRNA levels and transcription rates for the whole transcriptome after a shift from 25°C to 37°C. Using an established mathematical algorithm, theoretical mRNA decay rates have also been calculated from the experimental data. We have verified the mathematical predictions for selected genes by determining their mRNA decay rates at different times during heat stress response using the regulatable tetO promoter. This study indicates that the yeast response to heat shock is not only due to changes in transcription rates, but also to changes in the mRNA stabilities. mRNA stability is affected in 62% of the yeast genes and it is particularly important in shaping the mRNA profile of the genes belonging to the environmental stress response. In most cases, changes in transcription rates and mRNA stabilities are homodirectional for both parameters, although some interesting cases of antagonist behavior are found. The statistical analysis of gene targets and sequence motifs within the clusters of genes with similar behaviors shows that both transcriptional and post-transcriptional regulons apparently contribute to the general heat stress response by means of transcriptional factors and RNA binding proteins. PMID:21364882

Network inference reveals novel connections in pathways regulating growth and defense in the yeast salt response.

PubMed

MacGilvray, Matthew E; Shishkova, Evgenia; Chasman, Deborah; Place, Michael; Gitter, Anthony; Coon, Joshua J; Gasch, Audrey P

2018-05-01

Cells respond to stressful conditions by coordinating a complex, multi-faceted response that spans many levels of physiology. Much of the response is coordinated by changes in protein phosphorylation. Although the regulators of transcriptome changes during stress are well characterized in Saccharomyces cerevisiae, the upstream regulatory network controlling protein phosphorylation is less well dissected. Here, we developed a computational approach to infer the signaling network that regulates phosphorylation changes in response to salt stress. We developed an approach to link predicted regulators to groups of likely co-regulated phospho-peptides responding to stress, thereby creating new edges in a background protein interaction network. We then use integer linear programming (ILP) to integrate wild type and mutant phospho-proteomic data and predict the network controlling stress-activated phospho-proteomic changes. The network we inferred predicted new regulatory connections between stress-activated and growth-regulating pathways and suggested mechanisms coordinating metabolism, cell-cycle progression, and growth during stress. We confirmed several network predictions with co-immunoprecipitations coupled with mass-spectrometry protein identification and mutant phospho-proteomic analysis. Results show that the cAMP-phosphodiesterase Pde2 physically interacts with many stress-regulated transcription factors targeted by PKA, and that reduced phosphorylation of those factors during stress requires the Rck2 kinase that we show physically interacts with Pde2. Together, our work shows how a high-quality computational network model can facilitate discovery of new pathway interactions during osmotic stress.

Genome-wide organization and expression profiling of the NAC transcription factor family in potato (Solanum tuberosum L.).

PubMed

Singh, Anil Kumar; Sharma, Vishal; Pal, Awadhesh Kumar; Acharya, Vishal; Ahuja, Paramvir Singh

2013-08-01

NAC [no apical meristem (NAM), Arabidopsis thaliana transcription activation factor [ATAF1/2] and cup-shaped cotyledon (CUC2)] proteins belong to one of the largest plant-specific transcription factor (TF) families and play important roles in plant development processes, response to biotic and abiotic cues and hormone signalling. Our genome-wide analysis identified 110 StNAC genes in potato encoding for 136 proteins, including 14 membrane-bound TFs. The physical map positions of StNAC genes on 12 potato chromosomes were non-random, and 40 genes were found to be distributed in 16 clusters. The StNAC proteins were phylogenetically clustered into 12 subgroups. Phylogenetic analysis of StNACs along with their Arabidopsis and rice counterparts divided these proteins into 18 subgroups. Our comparative analysis has also identified 36 putative TNAC proteins, which appear to be restricted to Solanaceae family. In silico expression analysis, using Illumina RNA-seq transcriptome data, revealed tissue-specific, biotic, abiotic stress and hormone-responsive expression profile of StNAC genes. Several StNAC genes, including StNAC072 and StNAC101that are orthologs of known stress-responsive Arabidopsis RESPONSIVE TO DEHYDRATION 26 (RD26) were identified as highly abiotic stress responsive. Quantitative real-time polymerase chain reaction analysis largely corroborated the expression profile of StNAC genes as revealed by the RNA-seq data. Taken together, this analysis indicates towards putative functions of several StNAC TFs, which will provide blue-print for their functional characterization and utilization in potato improvement.

Transcriptomic analysis reveals numerous diverse protein kinases and transcription factors involved in desiccation tolerance in the resurrection plant Myrothamnus flabellifolia

PubMed Central

Ma, Chao; Wang, Hong; Macnish, Andrew J; Estrada-Melo, Alejandro C; Lin, Jing; Chang, Youhong; Reid, Michael S; Jiang, Cai-Zhong

2015-01-01

The woody resurrection plant Myrothamnus flabellifolia has remarkable tolerance to desiccation. Pyro-sequencing technology permitted us to analyze the transcriptome of M. flabellifolia during both dehydration and rehydration. We identified a total of 8287 and 8542 differentially transcribed genes during dehydration and rehydration treatments respectively. Approximately 295 transcription factors (TFs) and 484 protein kinases (PKs) were up- or down-regulated in response to desiccation stress. Among these, the transcript levels of 53 TFs and 91 PKs increased rapidly and peaked early during dehydration. These regulators transduce signal cascades of molecular pathways, including the up-regulation of ABA-dependent and independent drought stress pathways and the activation of protective mechanisms for coping with oxidative damage. Antioxidant systems are up-regulated, and the photosynthetic system is modified to reduce ROS generation. Secondary metabolism may participate in the desiccation tolerance of M. flabellifolia as indicated by increases in transcript abundance of genes involved in isopentenyl diphosphate biosynthesis. Up-regulation of genes encoding late embryogenesis abundant proteins and sucrose phosphate synthase is also associated with increased tolerance to desiccation. During rehydration, the transcriptome is also enriched in transcripts of genes encoding TFs and PKs, as well as genes involved in photosynthesis, and protein synthesis. The data reported here contribute comprehensive insights into the molecular mechanisms of desiccation tolerance in M. flabellifolia. PMID:26504577

Transcriptome and metabolome of synthetic Solanum autotetraploids reveal key genomic stress events following polyploidization.

PubMed

Fasano, Carlo; Diretto, Gianfranco; Aversano, Riccardo; D'Agostino, Nunzio; Di Matteo, Antonio; Frusciante, Luigi; Giuliano, Giovanni; Carputo, Domenico

2016-06-01

Polyploids are generally classified as autopolyploids, derived from a single species, and allopolyploids, arising from interspecific hybridization. The former represent ideal materials with which to study the consequences of genome doubling and ascertain whether there are molecular and functional rules operating following polyploidization events. To investigate whether the effects of autopolyploidization are common to different species, or if species-specific or stochastic events are prevalent, we performed a comprehensive transcriptomic and metabolomic characterization of diploids and autotetraploids of Solanum commersonii and Solanum bulbocastanum. Autopolyploidization remodelled the transcriptome and the metabolome of both species. In S. commersonii, differentially expressed genes (DEGs) were highly enriched in pericentromeric regions. Most changes were stochastic, suggesting a strong genotypic response. However, a set of robustly regulated transcripts and metabolites was also detected, including purine bases and nucleosides, which are likely to underlie a common response to polyploidization. We hypothesize that autopolyploidization results in nucleotide pool imbalance, which in turn triggers a genomic shock responsible for the stochastic events observed. The more extensive genomic stress and the higher number of stochastic events observed in S. commersonii with respect to S. bulbocastanum could be the result of the higher nucleoside depletion observed in this species. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Molecular response of canola to salt stress: insights on tolerance mechanisms.

PubMed

Shokri-Gharelo, Reza; Noparvar, Pouya Motie

2018-01-01

Canola ( Brassica napus L. ) is widely cultivated around the world for the production of edible oils and biodiesel fuel. Despite many canola varieties being described as 'salt-tolerant', plant yield and growth decline drastically with increasing salinity. Although many studies have resulted in better understanding of the many important salt-response mechanisms that control salt signaling in plants, detoxification of ions, and synthesis of protective metabolites, the engineering of salt-tolerant crops has only progressed slowly. Genetic engineering has been considered as an efficient method for improving the salt tolerance of canola but there are many unknown or little-known aspects regarding canola response to salinity stress at the cellular and molecular level. In order to develop highly salt-tolerant canola, it is essential to improve knowledge of the salt-tolerance mechanisms, especially the key components of the plant salt-response network. In this review, we focus on studies of the molecular response of canola to salinity to unravel the different pieces of the salt response puzzle. The paper includes a comprehensive review of the latest studies, particularly of proteomic and transcriptomic analysis, including the most recently identified canola tolerance components under salt stress, and suggests what researchers should focus on in future studies.

Industrial antifoam agents impair ethanol fermentation and induce stress responses in yeast cells.

PubMed

Nielsen, Jens Christian; Senne de Oliveira Lino, Felipe; Rasmussen, Thomas Gundelund; Thykær, Jette; Workman, Christopher T; Basso, Thiago Olitta

2017-11-01

The Brazilian sugarcane industry constitutes one of the biggest and most efficient ethanol production processes in the world. Brazilian ethanol production utilizes a unique process, which includes cell recycling, acid wash, and non-aseptic conditions. Process characteristics, such as extensive CO 2 generation, poor quality of raw materials, and frequent contaminations, all lead to excessive foam formation during fermentations, which is treated with antifoam agents (AFA). In this study, we have investigated the impact of industrial AFA treatments on the physiology and transcriptome of the industrial ethanol strain Saccharomyces cerevisiae CAT-1. The investigated AFA included industrially used AFA acquired from Brazilian ethanol plants and commercially available AFA commonly used in the fermentation literature. In batch fermentations, it was shown that industrial AFA compromised growth rates and glucose uptake rates, while commercial AFA had no effect in concentrations relevant for defoaming purposes. Industrial AFA were further tested in laboratory scale simulations of the Brazilian ethanol production process and proved to decrease cell viability compared to the control, and the effects were intensified with increasing AFA concentrations and exposure time. Transcriptome analysis showed that AFA treatments induced additional stress responses in yeast cells compared to the control, shown by an up-regulation of stress-specific genes and a down-regulation of lipid biosynthesis, especially ergosterol. By documenting the detrimental effects associated with chemical AFA, we highlight the importance of developing innocuous systems for foam control in industrial fermentation processes.

Transcriptomic analysis of the response of Acropora millepora to hypo-osmotic stress provides insights into DMSP biosynthesis by corals.

PubMed

Aguilar, Catalina; Raina, Jean-Baptiste; Motti, Cherie A; Fôret, Sylvain; Hayward, David C; Lapeyre, Bruno; Bourne, David G; Miller, David J

2017-08-14

Dimethylsulfoniopropionate (DMSP) is a small sulphur compound which is produced in prodigious amounts in the oceans and plays a pivotal role in the marine sulfur cycle. Until recently, DMSP was believed to be synthesized exclusively by photosynthetic organisms; however we now know that corals and specific bacteria can also produce this compound. Corals are major sources of DMSP, but the molecular basis for its biosynthesis is unknown in these organisms. Here we used salinity stress, which is known to trigger DMSP production in other organisms, in conjunction with transcriptomics to identify coral genes likely to be involved in DMSP biosynthesis. We focused specifically on both adults and juveniles of the coral Acropora millepora: after 24 h of exposure to hyposaline conditions, DMSP concentrations increased significantly by 2.6 fold in adult corals and 1.2 fold in juveniles. Concomitantly, candidate genes enabling each of the necessary steps leading to DMSP production were up-regulated. The data presented strongly suggest that corals use an algal-like pathway to generate DMSP from methionine, and are able to rapidly change expression of the corresponding genes in response to environmental stress. However, our data also indicate that DMSP is unlikely to function primarily as an osmolyte in corals, instead potentially serving as a scavenger of ROS and as a molecular sink for excess methionine produced as a consequence of proteolysis and osmolyte catabolism in corals under hypo-osmotic conditions.

Global De Novo Protein-Protein Interactome Elucidates Interactions of Drought-Responsive Proteins in Horse Gram (Macrotyloma uniflorum).

PubMed

Bhardwaj, Jyoti; Gangwar, Indu; Panzade, Ganesh; Shankar, Ravi; Yadav, Sudesh Kumar

2016-06-03

Inspired by the availability of de novo transcriptome of horse gram (Macrotyloma uniflorum) and recent developments in systems biology studies, the first ever global protein-protein interactome (PPI) map was constructed for this highly drought-tolerant legume. Large-scale studies of PPIs and the constructed database would provide rationale behind the interplay at cascading translational levels for drought stress-adaptive mechanisms in horse gram. Using a bidirectional approach (interolog and domain-based), a high-confidence interactome map and database for horse gram was constructed. Available transcriptomic information for shoot and root tissues of a sensitive (M-191; genotype 1) and a drought-tolerant (M-249; genotype 2) genotype of horse gram was utilized to draw comparative PPI subnetworks under drought stress. High-confidence 6804 interactions were predicted among 1812 proteins covering about one-fourth of the horse gram proteome. The highest number of interactions (33.86%) in horse gram interactome matched with Arabidopsis PPI data. The top five hub nodes mostly included ubiquitin and heat-shock-related proteins. Higher numbers of PPIs were found to be responsive in shoot tissue (416) and root tissue (2228) of genotype 2 compared with shoot tissue (136) and root tissue (579) of genotype 1. Characterization of PPIs using gene ontology analysis revealed that kinase and transferase activities involved in signal transduction, cellular processes, nucleocytoplasmic transport, protein ubiquitination, and localization of molecules were most responsive to drought stress. Hence, these could be framed in stress adaptive mechanisms of horse gram. Being the first legume global PPI map, it would provide new insights into gene and protein regulatory networks for drought stress tolerance mechanisms in horse gram. Information compiled in the form of database (MauPIR) will provide the much needed high-confidence systems biology information for horse gram genes, proteins, and involved processes. This information would ease the effort and increase the efficacy for similar studies on other legumes. Public access is available at http://14.139.59.221/MauPIR/ .

The Role of Tomato WRKY Genes in Plant Responses to Combined Abiotic and Biotic Stresses

PubMed Central

Bai, Yuling; Sunarti, Sri; Kissoudis, Christos; Visser, Richard G. F.; van der Linden, C. G.

2018-01-01

In the field, plants constantly face a plethora of abiotic and biotic stresses that can impart detrimental effects on plants. In response to multiple stresses, plants can rapidly reprogram their transcriptome through a tightly regulated and highly dynamic regulatory network where WRKY transcription factors can act as activators or repressors. WRKY transcription factors have diverse biological functions in plants, but most notably are key players in plant responses to biotic and abiotic stresses. In tomato there are 83 WRKY genes identified. Here we review recent progress on functions of these tomato WRKY genes and their homologs in other plant species, such as Arabidopsis and rice, with a special focus on their involvement in responses to abiotic and biotic stresses. In particular, we highlight WRKY genes that play a role in plant responses to a combination of abiotic and biotic stresses.

Five pectinase gene expressions highly responding to heat stress in rice floral organs revealed by RNA-seq analysis.

PubMed

Wu, Liquan; Taohua, Zhou; Gui, Wenbin; Xu, Lisen; Li, Juan; Ding, YanFeng

2015-07-31

Heat stress hurts rice, and floral organs are mostly sensitive to heat stress. We aimed to unravel molecular responses to heat stress in rice floral organs using Illumina/Solexa sequencing technology for addressing the increasing concern of globle warming. At meiophase of the pollen mother cell (pulvinus flat), the plants were stressed for 3 d at 38 C, and RNA was extracted from the stressed pistil and stamen for RNA-Seq sequencing to build the heat stress transcriptom library. A total of 7178 defferentially expressed genes (DEGs) between the normal and heat stress libraries were significant, 61% up-regulated and 39% down-regulated. The 7178 DEGs were significantly classified to 34 gene ontology (GO) categories, and 11 of the GO categories were significantly enriched. The GO:0016787 for hydrolase activity of molecular function was mostly enriched with the least probability, and included 11 DEGs named Hy1 - Hy11. Expression levels of five DEGs, Hy4 - Hy6 and Hy9 - Hy10 for starch and sucrose metablism via pectinase, increased 12 - 14 times in response to the heat stress. Further investigation of the five DEGs for pectin metabolism and association with reported heat responsive genes may help develop a molecular strategy to remedy heat damage in rice. Copyright © 2015 Elsevier Inc. All rights reserved.

Physiology and transcriptomics of water-deficit stress responses in wheat cultivars TAM 111 and TAM 112

USDA-ARS?s Scientific Manuscript database

Hard red winter wheat crops on the U.S. Southern Great Plains often experience moderate to severe drought stress, especially during the grain filling stage, resulting in significant yield losses. Cultivars TAM 111 and TAM 112 are widely cultivated in the region, share parentage and showed superior b...

Genetic variation of transgenerational plasticity of offspring germination in response to salinity stress and the seed transcriptome of Medicago truncatula.

PubMed

Vu, Wendy T; Chang, Peter L; Moriuchi, Ken S; Friesen, Maren L

2015-04-01

Transgenerational plasticity provides phenotypic variation that contributes to adaptation. For plants, the timing of seed germination is critical for offspring survival in stressful environments, as germination timing can alter the environmental conditions a seedling experiences. Stored seed transcripts are important determinants of seed germination, but have not previously been linked with transgenerational plasticity of germination behavior. In this study we used RNAseq and growth chamber experiments of the model legume M. trucantula to test whether parental exposure to salinity stress influences the expression of stored seed transcripts and early offspring traits and test for genetic variation. We detected genotype-dependent parental environmental effects (transgenerational plasticity) on the expression levels of stored seed transcripts, seed size, and germination behavior of four M. truncatula genotypes. More than 50% of the transcripts detected in the mature, ungerminated seed transcriptome were annotated as regulating seed germination, some of which are involved in abiotic stress response and post-embryonic development. Some genotypes showed increased seed size in response to parental exposure to salinity stress, but no parental environmental influence on germination timing. In contrast, other genotypes showed no seed size differences across contrasting parental conditions but displayed transgenerational plasticity for germimation timing, with significantly delayed germination in saline conditions when parental plants were exposed to salinity. In genotypes that show significant transgenerational plastic germination response, we found significant coexpression networks derived from salt responsive transcripts involved in post-transcriptional regulation of the germination pathway. Consistent with the delayed germination response to saline conditions in these genotypes, we found genes associated with dormancy and up-regulation of abscisic acid (ABA). Our results demonstrate genetic variation in transgenerational plasticity within M. truncatula and show that parental exposure to salinity stress influences the expression of stored seed transcripts, seed weight, and germination behavior. Furthermore, we show that the parental environment influences gene expression to modulate biological pathways that are likely responsible for offspring germination responses to salinity stress.

Differential Gene Expression Analysis in Polygonum minus Leaf upon 24 h of Methyl Jasmonate Elicitation

PubMed Central

Rahnamaie-Tajadod, Reyhaneh; Loke, Kok-Keong; Goh, Hoe-Han; Noor, Normah M.

2017-01-01

Polygonum minus is an herbal plant that grows in Southeast Asian countries and traditionally used as medicine. This plant produces diverse secondary metabolites such as phenolic compounds and their derivatives, which are known to have roles in plant abiotic and biotic stress responses. Methyl jasmonate (MeJA) is a plant signaling molecule that triggers transcriptional reprogramming in secondary metabolism and activation of defense responses against many biotic and abiotic stresses. However, the effect of MeJA elicitation on the genome-wide expression profile in the leaf tissue of P. minus has not been well-studied due to the limited genetic information. Hence, we performed Illumina paired-end RNA-seq for de novo reconstruction of P. minus leaf transcriptome to identify differentially expressed genes (DEGs) in response to MeJA elicitation. A total of 182,111 unique transcripts (UTs) were obtained by de novo assembly of 191.57 million paired-end clean reads using Trinity analysis pipeline. A total of 2374 UTs were identified to be significantly up-/down-regulated 24 h after MeJA treatment. These UTs comprising many genes related to plant secondary metabolite biosynthesis, defense and stress responses. To validate our sequencing results, we analyzed the expression of 21 selected DEGs by quantitative real-time PCR and found a good correlation between the two analyses. The single time-point analysis in this work not only provides a useful genomic resource for P. minus but also gives insights on molecular mechanisms of stress responses in P. minus. PMID:28220135

Global transcriptomic response of Anoxybacillus sp. SK 3-4 to aluminum exposure.

PubMed

Lim, Jia Chun; Thevarajoo, Suganthi; Selvaratnam, Chitra; Goh, Kian Mau; Shamsir, Mohd Shahir; Ibrahim, Zaharah; Chong, Chun Shiong

2017-02-01

Anoxybacillus sp. SK 3-4 is a Gram-positive, rod-shaped bacterium and a member of family Bacillaceae. We had previously reported that the strain is an aluminum resistant thermophilic bacterium. This is the first report to provide a detailed analysis of the global transcriptional response of Anoxybacillus when the cells were exposed to 600 mg L -1 of aluminum. The transcriptome was sequenced using Illumina MiSeq sequencer. Total of 708 genes were differentially expressed (fold change >2.00) with 316 genes were up-regulated while 347 genes were down-regulated, in comparing to control with no aluminum added in the culture. Based on Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, the majority of genes encoding for cell metabolism such as glycolysis, sulfur metabolism, cysteine and methionine metabolism were up-regulated; while most of the gene associated with tricarboxylic acid cycle (TCA cycle) and valine, leucine and isoleucine metabolism were down-regulated. In addition, a significant number of the genes encoding ABC transporters, metal ions transporters, and some stress response proteins were also differentially expressed following aluminum exposure. The findings provide further insight and help us to understand on the resistance of Anoxybacillus sp. SK 3-4 toward aluminium. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Proteomic and Transcriptomic Analysis of Aspergillus fumigatus on Exposure to Amphotericin B▿ †

PubMed Central

Gautam, Poonam; Shankar, Jata; Madan, Taruna; Sirdeshmukh, Ravi; Sundaram, Curam Sreenivasacharlu; Gade, Wasudev Namdeo; Basir, Seemi Farhat; Sarma, Puranam Usha

2008-01-01

Amphotericin B (AMB) is the most widely used polyene antifungal drug for the treatment of systemic fungal infections, including invasive aspergillosis. It has been our aim to understand the molecular targets of AMB in Aspergillus fumigatus by genomic and proteomic approaches. In transcriptomic analysis, a total of 295 genes were found to be differentially expressed (165 upregulated and 130 downregulated), including many involving the ergosterol pathway, cell stress proteins, cell wall proteins, transport proteins, and hypothetical proteins. Proteomic profiles of A. fumigatus alone or A. fumigatus treated with AMB showed differential expression levels for 85 proteins (76 upregulated and 9 downregulated). Forty-eight of them were identified with high confidence and belonged to the above-mentioned categories. Differential expression levels for Rho-GDP dissociation inhibitor (Rho-GDI), secretory-pathway GDI, clathrin, Sec 31 (a subunit of the exocyst complex), and RAB GTPase Ypt51 in response to an antifungal drug are reported here for the first time and may represent a specific response of A. fumigatus to AMB. The expression of some of these genes was validated by real-time reverse transcription-PCR. The AMB responsive genes/proteins observed to be differentially expressed in A. fumigatus may be further explored for novel drug development. PMID:18838595