The potential signalling pathways which regulate surface changes induced by phytohormones in the potato cyst nematode (Globodera rostochiensis).

PubMed

Akhkha, A; Curtis, R; Kennedy, M; Kusel, J

2004-05-01

It has been demonstrated that the surface lipophilicity of the plant-parasitic nematode Globodera rostochiensis decreases when infective larvae are exposed to the phytohormones indole-3-acetic acid (auxin) or kinetin (cytokinin). In the present study, it was shown that inhibition of phospholipase C (PLC) or phosphatidylinositol 3 kinase (PI3-kinase) reversed the effect of phytohormones on surface lipophilicity. The signalling pathway(s) involved in surface modification were investigated using 'caged' signalling molecules and stimulators or inhibitors of different signalling enzymes. Photolysis of the 'caged' signalling molecules, NPE-caged Ins 1,4,5-P3, NITR-5/AM or caged-cAMP to liberate IP3, Ca2+ or cAMP respectively, decreased the surface lipophilicity. Activation of adenylate cyclase also decreased the surface lipophilicity. In contrast, inhibition of PI3-kinase using Wortmannin, LY-294002 or Quercetin, and inhibition of PLC using U-73122 all increased the surface lipophilicity. Two possible signalling pathways involved in phytohormone-induced surface modification are proposed.

An ultrahigh-performance liquid chromatography method with electrospray ionization tandem mass spectrometry for simultaneous quantification of five phytohormones in medicinal plant Glycyrrhiza uralensis under abscisic acid stress.

PubMed

Xiang, Yu; Song, Xiaona; Qiao, Jing; Zang, Yimei; Li, Yanpeng; Liu, Yong; Liu, Chunsheng

2015-07-01

An efficient simplified method was developed to determine multiple classes of phytohormones simultaneously in the medicinal plant Glycyrrhiza uralensis. Ultrahigh-performance liquid chromatography electrospray ionization tandem mass spectrometry (UPLC/ESI-MS/MS) with multiple reaction monitoring (MRM) in negative mode was used for quantification. The five studied phytohormones are gibberellic acid (GA3), abscisic acid (ABA), jasmonic acid (JA), indole-3-acetic acid, and salicylic acid (SA). Only 100 mg of fresh leaves was needed, with one purification step based on C18 solid-phase extraction. Cinnamic acid was chosen as the internal standard instead of isotope-labeled internal standards. Under the optimized conditions, the five phytohormones with internal standard were separated within 4 min, with good linearities and high sensitivity. The validated method was applied to monitor the spatial and temporal changes of the five phytohormones in G. uralensis under ABA stress. The levels of GA3, ABA, JA, and SA in leaves of G. uralensis were increased at different times and with different tendencies in the reported stress mode. These changes in phytohormone levels are discussed in the context of a possible feedback regulation mechanism. Understanding this mechanism will provide a good chance of revealing the mutual interplay between different biosynthetic routes, which could further help elucidate the mechanisms of effective composition accumulation in medicinal plants.

Biochemical characterization in Norway spruce (Picea abies) of SABATH methyltransferases that methylate phytohormones.

PubMed

Chaiprasongsuk, Minta; Zhang, Chi; Qian, Ping; Chen, Xinlu; Li, Guanglin; Trigiano, Robert N; Guo, Hong; Chen, Feng

2018-05-01

Indole-3-acetic acid (IAA), gibberellins (GAs), salicylic acid (SA) and jasmonic acid (JA) exist in methyl ester forms in plants in addition to their free acid forms. The enzymes that catalyze methylation of these carboxylic acid phytohormones belong to a same protein family, the SABATH methyltransferases. While the genes encoding these enzymes have been isolated from a small number of flowering plants, little is known about their occurrence and evolution in non-flowering plants. Here, we report the systematic characterization of the SABATH family from Norway spruce (Picea abies), a gymnosperm. The Norway spruce genome contains ten SABATH genes (PaSABATH1-10). Full-length cDNA for each of the ten PaSABATH genes was cloned and expressed in Escherichia coli. Recombinant PaSABATHs were tested for activity with IAA, GA, SA, and JA. Among the ten PaSABATHs, five had activity with one or more of the four substrates. PaSABATH1 and PaSABATH2 had the highest activities with IAA and SA, respectively. PaSABATH4, PaSABATH5 and PaSABATH10 all had JA as a preferred substrate but with notable differences in biochemical properties. The structural basis of PaSABATHs in discriminating various phytohormone substrates was inferred based on structural models of the enzyme-substrate complexes. The phylogeny of PaSABATHs with selected SABATHs from other plants implies that the enzymes methylating IAA are conserved in seed plants whereas the enzymes methylating JA and SA have independent evolution in gymnosperms and angiosperms. Copyright © 2018 Elsevier Ltd. All rights reserved.

Abiotic stress and phytohormones affect enzymic activity of 1-O-(indole-3-acetyl)-β-d-glucose: myo-inositol indoleacetyl transferase from rice (Oryza sativa).

PubMed

Ciarkowska, Anna; Ostrowski, Maciej; Jakubowska, Anna

2016-10-20

Indole-3-acetic acid (IAA) conjugation is a part of mechanism regulating free auxin concentration. 1-O-(indole-3-acetyl)-β-d-glucose: myo-inositol indoleacetyl transferase (IAInos synthase) is an enzyme involved in IAA-ester conjugates biosynthesis. Biotic and abiotic stress conditions can modulate auxin conjugates formation in plants. In this study, we investigated effect of plant hormones (IAA, ABA, SA and 2,4-D) and abiotic stress (drought and salt stress: 150mM NaCl and 300mM NaCl) on expression level and catalytic activity of rice IAInos synthase. Enzymic activity assay indicated that all tested phytohormones affected activity of IAInos synthase, but only ABA had inhibiting effect, while IAA, SA and 2,4-D activated the enzyme. Drought and salt stress induced with lower NaCl concentration resulted in decreased activity of IAInos synthase, but 300mM NaCl had no effect on the enzyme. Despite observed differences in enzymic activities, no changes of expression level, tested by semiquantitative RT-PCR and Western blot, were detected. Based on our results it has been supposed that plant hormones and stress conditions affect IAInos synthase activity on posttranslational level. Copyright © 2016 Elsevier GmbH. All rights reserved.

Abscisic Acid-Cytokinin Antagonism Modulates Resistance Against Pseudomonas syringae in Tobacco.

PubMed

Großkinsky, Dominik K; van der Graaff, Eric; Roitsch, Thomas

2014-12-01

Phytohormones are known as essential regulators of plant defenses, with ethylene, jasmonic acid, and salicylic acid as the central immunity backbone, while other phytohormones have been demonstrated to interact with this. Only recently, a function of the classic phytohormone cytokinin in plant immunity has been described in Arabidopsis, rice, and tobacco. Although interactions of cytokinins with salicylic acid and auxin have been indicated, the complete network of cytokinin interactions with other immunity-relevant phytohormones is not yet understood. Therefore, we studied the interaction of kinetin and abscisic acid as a negative regulator of plant immunity to modulate resistance in tobacco against Pseudomonas syringae. By analyzing infection symptoms, pathogen proliferation, and accumulation of the phytoalexin scopoletin as a key mediator of kinetin-induced resistance in tobacco, antagonistic interaction of these phytohormones in plant immunity was identified. Kinetin reduced abscisic acid levels in tobacco, while increased abscisic acid levels by exogenous application or inhibition of abscisic acid catabolism by diniconazole neutralized kinetin-induced resistance. Based on these results, we conclude that reduction of abscisic acid levels by enhanced abscisic acid catabolism strongly contributes to cytokinin-mediated resistance effects. Thus, the identified cytokinin-abscisic acid antagonism is a novel regulatory mechanism in plant immunity.

The Promoter of AtUSP Is Co-regulated by Phytohormones and Abiotic Stresses in Arabidopsis thaliana.

PubMed

Bhuria, Monika; Goel, Parul; Kumar, Sanjay; Singh, Anil K

2016-01-01

Universal stress proteins (USPs) are known to be expressed in response to various abiotic stresses in a wide variety of organisms, such as bacteria, archaebacteria, protists, algae, fungi, plants, and animals. However, in plants, biological function of most of the USPs still remains obscure. In the present study, Arabidopsis USP gene ( AtUSP ) showed induction in response to abscisic acid (ABA) and various abiotic stresses viz . heat, dehydration, salt, osmotic, and cold stresses. Additionally, in silico analysis of AtUSP promoter identified several cis -elements responsive to phytohormones and abiotic stresses such as ABRE, ERE, DRE, and HSE, etc. To functionally validate the AtUSP promoter, the 1115 bp region of promoter was characterized under phytohormone and abiotic stress treatments. Deletion analysis of promoter was carried out by cloning the full length promoter (D0) and its three 5' deletion derivatives, D1 (964 bp), D2 (660 bp), and D3 (503 bp) upstream of the β-glucuronidase (GUS) reporter gene, which were then stably transformed in Arabidopsis plants. The AtUSP promoter (D0) showed minimal activity under non-stress conditions which was enhanced in response to phytohormone treatments (ABA and ACC) and abiotic stresses such as dehydration, heat, cold, salt, and osmotic stresses. The seedlings harboring D1 and D2 deletion fragments showed constitutive GUS expression even under control condition with increased activity almost under all the treatments. However, D3 seedlings exhibited complete loss of activity under control condition with induction under ACC treatment, dehydration, heat, oxidative, salt, and osmotic stresses. Thus, present study clearly showed that AtUSP promoter is highly inducible by phytohormones and multiple abiotic stresses and it can be exploited as stress inducible promoter to generate multi-stress tolerant crops with minimal effects on their other important traits.

Phytohormone profiles induced by trichoderma isolates correspond with their biocontrol and plant growth-promoting activity on melon plants.

PubMed

Martínez-Medina, Ainhoa; Del Mar Alguacil, Maria; Pascual, Jose A; Van Wees, Saskia C M

2014-07-01

The application of Trichoderma strains with biocontrol and plant growth-promoting capacities to plant substrates can help reduce the input of chemical pesticides and fertilizers in agriculture. Some Trichoderma isolates can directly affect plant pathogens, but they also are known to influence the phytohormonal network of their host plant, thus leading to an improvement of plant growth and stress tolerance. In this study, we tested whether alterations in the phytohormone signature induced by different Trichoderma isolates correspond with their ability for biocontrol and growth promotion. Four Trichoderma isolates were collected from agricultural soils and were identified as the species Trichoderma harzianum (two isolates), Trichoderma ghanense, and Trichoderma hamatum. Their antagonistic activity against the plant pathogen Fusarium oxysporum f. sp. melonis was tested in vitro, and their plant growth-promoting and biocontrol activity against Fusarium wilt on melon plants was examined in vivo, and compared to that of the commercial strain T. harzianum T-22. Several growth- and defense-related phytohormones were analyzed in the shoots of plants that were root-colonized by the different Trichoderma isolates. An increase in auxin and a decrease in cytokinins and abscisic acid content were induced by the isolates that promoted the plant growth. Principal component analysis (PCA) was used to evaluate the relationship between the plant phenotypic and hormonal variables. PCA pointed to a strong association of auxin induction with plant growth stimulation by Trichoderma. Furthermore, the disease-protectant ability of the Trichoderma strains against F. oxysporum infection seems to be more related to their induced alterations in the content of the hormones abscisic acid, ethylene, and the cytokinin trans-zeatin riboside than to the in vitro antagonism activity against F. oxysporum.

Zooming In on Plant Hormone Analysis: Tissue- and Cell-Specific Approaches.

PubMed

Novák, Ondřej; Napier, Richard; Ljung, Karin

2017-04-28

Plant hormones are a group of naturally occurring, low-abundance organic compounds that influence physiological processes in plants. Our knowledge of the distribution profiles of phytohormones in plant organs, tissues, and cells is still incomplete, but advances in mass spectrometry have enabled significant progress in tissue- and cell-type-specific analyses of phytohormones over the last decade. Mass spectrometry is able to simultaneously identify and quantify hormones and their related substances. Biosensors, on the other hand, offer continuous monitoring; can visualize local distributions and real-time quantification; and, in the case of genetically encoded biosensors, are noninvasive. Thus, biosensors offer additional, complementary technologies for determining temporal and spatial changes in phytohormone concentrations. In this review, we focus on recent advances in mass spectrometry-based quantification, describe monitoring systems based on biosensors, and discuss validations of the various methods before looking ahead at future developments for both approaches.

Evaluation of plant growth regulators to increase nickel phytoextraction by Alyssum species.

PubMed

Cabello-Conejo, M I; Centofanti, T; Kidd, P S; Prieto-Fernández, A; Chaney, R L

2013-01-01

Recent studies have shown that application of phytohormones to shoots of Alyssum murale increased biomass production but did not increase Ni shoot concentration. Increased biomass and Ni phytoextraction efficiency is useful to achieve economically viable phytomining. The objective of this study was to evaluate the effect of two types of phytohormones on the Ni phytoextraction capacity of four Alyssum species. Two different commercially available phytohormones (Cytokin and Promalin) based on cytokinins and/or gibberellins were applied on shoot biomass of four Ni hyperaccumulating Alyssum species (A. corsicum, A. malacitanum, A. murale, and A. pintodasilvae). Cytokin was applied in two concentrations and promalin in one concentration. The application of phytohormones had no clear positive effect on biomass production, Ni accumulation and Ni phytoextraction efficiency in the studied Alyssum species. A. malacitanum was the only species in which a significantly negative effect of these treatments was observed (in Ni uptake). A slightly positive response to promalin treatment was observed in the biomass production and Ni phytoextraction efficiency of A. corsicum. Although this effect was not significant it does indicate a potential application of these approaches to improve phytoextraction ability. Further studies will be needed to identify the most adequate phytohormone treatment as well as the appropriate concentrations and application times.

High efficiency stratification of apple cultivar Ligol seed dormancy by phytohormones, heat shock and pulsed radio frequency.

PubMed

Grzesik, Mieczysław; Górnik, Krzysztof; Janas, Regina; Lewandowki, Mariusz; Romanowska-Duda, Zdzislawa; Duijn, Bert van

2017-12-01

The aim of the study was to improve the effect of stratification of apple "Ligol" seeds by application of selected compounds, phytohormones, and physical methods For this purpose the seeds were stratified at 3°C in distilled water or in the presence of potassium nitrate (KNO 3 ), ethephon (ET), carbon monoxide (CO), hydrogen peroxide (H 2 O 2 ), a mixture of KNO 3 , ET, CO, H 2 O 2 , gibberellins (GA 3 ), 6-benzylaminopurine (BAP), jasmonic acid (JA), salicylic acid (SA) and a mixture of SA, GA 3 , BAP, JA, nitric oxide (NO), hydrogen chloride (HCL). Arranged protocols included various durations and combinations of selected compounds and phytohormones as well as laser and red light, heat shock - 2h heat shock (45°C) and Pulsed Radio Frequency (PRF) were investigated by germination tests and the activity of selected enzymes, gas exchange and index of chlorophyll in leaves. The obtained results showed the possibility to shorten more effectively the time of the apple 'Ligol' dormancy removal by treatments of the stratified seeds at 3°C with different biological and physical methods Selected compounds and phytohormones acted collectively as a regulatory complex controlling the course of release from dormancy. Physical methods (PRF and heat shock) additionally contributed to dormancy breakage. Duration of phytohormones or compounds impacts during stratification should be prolonged to minimum 7days to assure more balanced conditions of the regulatory complex for the acceleration of dormancy a removal. The most beneficial results were obtained after seed stratification for 7days on filter paper moistened in KNO 3 +Etephon+CO+H 2 O 2 at 3°C, and then on filter paper moistened in phytohormones (GA 3 +BAP+JA) till the end of seed germination (3°C). The application of this protocol could be a very useful tool in a shortening the apple breeding cycle since the period of removing dormancy was reduced by 38days in comparison to stratified in water. PRF has also the additive role in breaking dormancy of apple 'Ligol' seed. Positive effects of compounds and phytohormones applied during stratification remarkably accelerated the growth of developed from them seedlings. Further research is needed to optimize stratification methods with appropriate contents and concentrations of compounds and phytohormones combined with PRF exposure. Copyright © 2017 Elsevier GmbH. All rights reserved.

Heat-induced phytohormone changes are associated with disrupted early reproductive development and reduced yield in rice

PubMed Central

Wu, Chao; Cui, Kehui; Wang, Wencheng; Li, Qian; Fahad, Shah; Hu, Qiuqian; Huang, Jianliang; Nie, Lixiao; Peng, Shaobing

2016-01-01

Heat stress causes morphological and physiological changes and reduces crop yield in rice (Oryza sativa). To investigate changes in phytohormones and their relationships with yield and other attributes under heat stress, four rice varieties (Nagina22, Huanghuazhan, Liangyoupeijiu, and Shanyou 63) were grown in pots and subjected to three high temperature treatments plus control in temperature-controlled greenhouses for 15 d during the early reproductive phase. Yield reductions in Nagina22, Huanghuazhan, and Liangyoupeijiu were attributed to reductions in spikelet fertility, spikelets per panicle, and grain weight. The adverse effects of high temperature were alleviated by application of exogenous 6-benzylaminopurine (6-BA) in the heat-susceptible Liangyoupeijiu. High temperature stress reduced active cytokinins, gibberellin A1 (GA1), and indole-3-acetic acid (IAA), but increased abscisic acid (ABA) and bound cytokinins in young panicles. Correlation analyses and application of exogenous 6-BA revealed that high temperature-induced cytokinin changes may regulate yield components by modulating the differentiation and degradation of branches and spikelets, panicle exsertion, pollen vigor, anther dehiscence, and grain size. Heat-tolerant Shanyou 63 displayed minor changes in phytohormones, panicle formation, and grain yield under high temperature compared with those of the other three varieties. These results suggest that phytohormone changes are closely associated with yield formation, and a small reduction or stability in phytohormone content is required to avoid large yield losses under heat stress. PMID:27713528

Phytohormone Signaling of the Resistance to Plum pox virus (PPV, Sharka Disease) Induced by Almond (Prunus dulcis (Miller) Webb) Grafting to Peach (P. persica L. Batsch).

PubMed

Dehkordi, Azam Nikbakht; Rubio, Manuel; Babaeian, Nadali; Albacete, Alfonso; Martínez-Gómez, Pedro

2018-05-03

Plum pox virus (PPV, sharka) is a limiting factor for peach production, and no natural sources of resistance have been described. Recent studies, however, have demonstrated that grafting the almond cultivar "Garrigues" onto the "GF305" peach infected with Dideron-type (PPV-D) isolates progressively reduces disease symptoms and virus accumulation. Furthermore, grafting "Garrigues" onto "GF305" prior to PPV-D inoculation has been found to completely prevent virus infection, showing that resistance is constitutive and not induced by the virus. To unravel the phytohormone signaling of this mechanism, we analyzed the following phytohormones belonging to the principal hormone classes: the growth-related phytohormones cytokinin trans-zeatin (tZ) and the gibberellins GA₃ and GA₄; and the stress-related phytohormones ethylene acid precursor 1-aminocyclopropane-1-carboxylic acid (ACC), abscisic acid (ABA), salicylic acid (SA), and jasmonic acid (JA). PPV inoculation produced a significant increase in GA₃ and ABA in peach, and these imbalances were related to the presence of chlorosis symptoms. However, grafting "Garrigues" almond onto the PPV-inoculated "GF305" peach produced the opposite effect, reducing GA₃ and ABA contents in parallel to the elimination of symptoms. Our results showed the significant implication of SA in this induced resistance in peach with an additional effect on tZ and JA concentrations. This SA-induced resistance based in the decrease in symptoms seems to be different from Systemic Acquired Resistance (SAR) and Induced Systemic Resistance (ISR), which are based in other reactions producing necrosis. Further studies are necessary, however, to validate these results against PPV-D isolates in the more aggressive Marcus-type (PPV-M) isolates.

Expression profiling and functional analysis reveals that TOR is a key player in regulating photosynthesis and phytohormone signaling pathways in Arabidopsis

PubMed Central

Dong, Pan; Xiong, Fangjie; Que, Yumei; Wang, Kai; Yu, Lihua; Li, Zhengguo; Ren, Maozhi

2015-01-01

Target of rapamycin (TOR) acts as a master regulator to control cell growth by integrating nutrient, energy, and growth factors in all eukaryotic species. TOR plays an evolutionarily conserved role in regulating the transcription of genes associated with anabolic and catabolic processes in Arabidopsis, but little is known about the functions of TOR in photosynthesis and phytohormone signaling, which are unique features of plants. In this study, AZD8055 (AZD) was screened as the strongest active-site TOR inhibitor (asTORi) in Arabidopsis compared with TORIN1 and KU63794 (KU). Gene expression profiles were evaluated using RNA-seq after treating Arabidopsis seedlings with AZD. More than three-fold differentially expressed genes (DEGs) were identified in AZD-treated plants relative to rapamycin-treated plants in previous studies. Most of the DEGs and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways involved in cell wall elongation, ribosome biogenesis, and cell autophagy were common to both AZD- and rapamycin-treated samples, but AZD displayed much broader and more efficient inhibition of TOR compared with rapamycin. Importantly, the suppression of TOR by AZD resulted in remodeling of the expression profile of the genes associated with photosynthesis and various phytohormones, indicating that TOR plays a crucial role in modulating photosynthesis and phytohormone signaling in Arabidopsis. These newly identified DEGs expand the understanding of TOR signaling in plants. This study elucidates the novel functions of TOR in photosynthesis and phytohormone signaling and provides a platform to study the downstream targets of TOR in Arabidopsis. PMID:26442001

Potential link between fruit yield, quality parameters and phytohormonal changes in preharvest UV-C treated strawberry.

PubMed

Xu, Yanqun; Charles, Marie Thérèse; Luo, Zisheng; Roussel, Dominique; Rolland, Daniel

2017-07-01

Preharvest ultraviolet-C (UV-C) treatment of strawberry is a very new approach, and little information is available on the effect of this treatment on plant growth regulators. In this study, the effect of preharvest UV-C irradiations at three different doses on strawberry yield, fruit quality parameters and endogenous phytohormones was investigated simultaneously. The overall marketable yield of strawberry was not affected by the preharvest UV-C treatments, although more aborted and misshapen fruits were found in UV-C treated groups than in the untreated control. The fruits in the high dose group were firmer and had approximately 20% higher sucrose content and 15% higher ascorbic acid content than the control, while fruits from the middle and low dose groups showed no significant changes in these parameters. The lower abscisic acid (ABA) content found in the fruits in the high UV-C group may be associated with those quality changes. The citric acid content decreased only in the low dose group (reduction of 5.8%), with a concomitant 37% reduction in jasmonic acid (JA) content, compared to the control. The antioxidant status of fruits that received preharvest UV-C treatment was considered enhanced based on their oxygen radical absorbance capacity (ORAC) and malondialdehyde (MDA) content. In terms of aroma, three volatile alcohols differed significantly among the various treatments with obvious activation of alcohol acyltransferase (AAT) activity. The observed synchronous influence on physiological indexes and related phytohormones suggests that preharvest UV-C might affect fruit quality via the action of plant hormones. Crown Copyright © 2017. Published by Elsevier Masson SAS. All rights reserved.

Phytohormone Involvement in the Ustilago maydis– Zea mays Pathosystem: Relationships between Abscisic Acid and Cytokinin Levels and Strain Virulence in Infected Cob Tissue

PubMed Central

Morrison, Erin N.; Emery, R. J. Neil; Saville, Barry J.

2015-01-01

Ustilago maydis is the causative agent of common smut of corn. Early studies noted its ability to synthesize phytohormones and, more recently these growth promoting substances were confirmed as cytokinins (CKs). Cytokinins comprise a group of phytohormones commonly associated with actively dividing tissues. Lab analyses identified variation in virulence between U. maydis dikaryon and solopathogen infections of corn cob tissue. Samples from infected cob tissue were taken at sequential time points post infection and biochemical profiling was performed using high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI MS/MS). This hormone profiling revealed that there were altered levels of ABA and major CKs, with a marked reduction in CK glucosides, increases in methylthiol CKs and a particularly dramatic increase in cisZ CK forms, in U. maydis infected tissue. These changes were more pronounced in the more virulent dikaryon relative to the solopathogenic strain suggesting a role for cytokinins in moderating virulence during biotrophic infection. These findings highlight the fact that U. maydis does not simply mimic a fertilized seed but instead reprograms the host tissue. Results underscore the suitability of the Ustilago maydis– Zea mays model as a basis for investigating the control of phytohormone dynamics during biotrophic infection of plants. PMID:26107181

A Quantitative Profiling Method of Phytohormones and Other Metabolites Applied to Barley Roots Subjected to Salinity Stress

PubMed Central

Cao, Da; Lutz, Adrian; Hill, Camilla B.; Callahan, Damien L.; Roessner, Ute

2017-01-01

As integral parts of plant signaling networks, phytohormones are involved in the regulation of plant metabolism and growth under adverse environmental conditions, including salinity. Globally, salinity is one of the most severe abiotic stressors with an estimated 800 million hectares of arable land affected. Roots are the first plant organ to sense salinity in the soil, and are the initial site of sodium (Na+) exposure. However, the quantification of phytohormones in roots is challenging, as they are often present at extremely low levels compared to other plant tissues. To overcome this challenge, we developed a high-throughput LC-MS method to quantify ten endogenous phytohormones and their metabolites of diverse chemical classes in roots of barley. This method was validated in a salinity stress experiment with six barley varieties grown hydroponically with and without salinity. In addition to phytohormones, we quantified 52 polar primary metabolites, including some phytohormone precursors, using established GC-MS and LC-MS methods. Phytohormone and metabolite data were correlated with physiological measurements including biomass, plant size and chlorophyll content. Root and leaf elemental analysis was performed to determine Na+ exclusion and K+ retention ability in the studied barley varieties. We identified distinct phytohormone and metabolite signatures as a response to salinity stress in different barley varieties. Abscisic acid increased in the roots of all varieties under salinity stress, and elevated root salicylic acid levels were associated with an increase in leaf chlorophyll content. Furthermore, the landrace Sahara maintained better growth, had lower Na+ levels and maintained high levels of the salinity stress linked metabolite putrescine as well as the phytohormone metabolite cinnamic acid, which has been shown to increase putrescine concentrations in previous studies. This study highlights the importance of root phytohormones under salinity stress and the multi-variety analysis provides an important update to analytical methodology, and adds to the current knowledge of salinity stress responses in plants at the molecular level. PMID:28119732

Long-distance transport of phytohormones through the plant vascular system.

PubMed

Lacombe, Benoit; Achard, Patrick

2016-12-01

Phytohormones are a group of low abundance molecules that activate various metabolic and developmental processes in response to environmental and endogenous signals. Like animal hormones, plant hormones often have distinct source and target tissues, hence ensuring long-range communication at the whole-plant level. Plants rely on various hormone distribution mechanisms depending on the distance and the direction of the transport. Here, we highlight the recent findings on the long-distance movement of plant hormones within the vasculature, from the physiological role to the molecular mechanism of the transport. Copyright © 2016 Elsevier Ltd. All rights reserved.

Bio-prospecting of soil Streptomyces and its bioassay-guided isolation of microbial derived auxin with antifungal properties.

PubMed

Saravana Kumar, P; Yuvaraj, P; Gabrial Paulraj, M; Ignacimuthu, S; Abdullah Al-Dhabi, N

2018-06-05

The present study was aimed to isolate bioactive actinomycetes with antifungal properties. Twenty-seven distinct soil derived actinomycetes were investigated for their antifungal activities. Among these, one isolate exhibited significant antifungal activity. Phenotypic and 16s rRNA gene sequence analysis strongly suggested that the active isolate BG4 belonged to the genus Streptomyces. Further, the chemical investigation of the active extract resulted in the isolation of a major compound and it was structurally elucidated as phenyl acetic acid (PAA). PAA exhibited promising antifungal activity with 100% inhibition, ranging from 31.25 to 25μg/mL. It is to be noted that PAA is naturally occurring and biologically active auxin. In addition, it has also been hypothesized that phytohormone endorsing the source of soil-symbionts has similar pathways for synthesizing compounds and its congeners of host due to horizontal gene transfer. These findings demonstrate that microbially derived phytohormone can be used to treat fungal infections. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Genome-wide analysis of the GH3 family in apple (Malus × domestica).

PubMed

Yuan, Huazhao; Zhao, Kai; Lei, Hengjiu; Shen, Xinjie; Liu, Yun; Liao, Xiong; Li, Tianhong

2013-05-02

Auxin plays important roles in hormone crosstalk and the plant's stress response. The auxin-responsive Gretchen Hagen3 (GH3) gene family maintains hormonal homeostasis by conjugating excess indole-3-acetic acid (IAA), salicylic acid (SA), and jasmonic acids (JAs) to amino acids during hormone- and stress-related signaling pathways. With the sequencing of the apple (Malus × domestica) genome completed, it is possible to carry out genomic studies on GH3 genes to indentify candidates with roles in abiotic/biotic stress responses. Malus sieversii Roem., an apple rootstock with strong drought tolerance and the ancestral species of cultivated apple species, was used as the experimental material. Following genome-wide computational and experimental identification of MdGH3 genes, we showed that MdGH3s were differentially expressed in the leaves and roots of M. sieversii and that some of these genes were significantly induced after various phytohormone and abiotic stress treatments. Given the role of GH3 in the negative feedback regulation of free IAA concentration, we examined whether phytohormones and abiotic stresses could alter the endogenous auxin level. By analyzing the GUS activity of DR5::GUS-transformed Arabidopsis seedlings, we showed that ABA, SA, salt, and cold treatments suppressed the auxin response. These findings suggest that other phytohormones and abiotic stress factors might alter endogenous auxin levels. Previous studies showed that GH3 genes regulate hormonal homeostasis. Our study indicated that some GH3 genes were significantly induced in M. sieversii after various phytohormone and abiotic stress treatments, and that ABA, SA, salt, and cold treatments reduce the endogenous level of axuin. Taken together, this study provides evidence that GH3 genes play important roles in the crosstalk between auxin, other phytohormones, and the abiotic stress response by maintaining auxin homeostasis.

Simultaneous analysis of ten phytohormones in Sargassum horneri by high-performance liquid chromatography with electrospray ionization tandem mass spectrometry.

PubMed

Li, Yan; Zhou, Chengxu; Yan, Xiaojun; Zhang, Jinrong; Xu, Jilin

2016-05-01

Phytohormones have attracted wide attention due to their important biological functions. However, their detection is still a challenge because of their complex composition, low abundance and diverse sources. In this study, a novel method of high-performance liquid chromatography with electrospray ionization tandem mass spectrometry was developed and validated for the simultaneous determination of ten phytohormones including indole-3-acetic acid, isopentenyladenine, isopentenyl adenosine, trans-zeatin riboside, zeatin, strigolactones, abscisic acid, salicylic acid, gibberellin A3, and jasmonic acid in Sargassum horneri (S. horneri). The phytohormones were extracted from freeze-dried S. horneri with methanol/water/methanoic acid (15:4:1, v/v/v) analyzed on a Hypersil Gold C18 column and detected by electrospray ionization tandem triple quadrupole mass spectrometry in the multiple reaction monitoring mode. The experimental conditions for the extraction and analysis of phytohormones were optimized and validated in terms of reproducibility, linearity, sensitivity, recovery, accuracy, and stability. Distributions of the phytohormones in the stems, blades, and gas bladder of the S. horneri in drift, fixed, and semi-fixed growing states were investigated for the first time. The observed contents of the phytohormones in S. horneri range from not detected to 5066.67 ng/g (fresh weight). Most phytohormones are distributed mainly in the stems of S. horneri in drift and semi-fixed states. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The influence of abscisic acid on the ethylene biosynthesis pathway in the functioning of the flower abscission zone in Lupinus luteus.

PubMed

Wilmowicz, Emilia; Frankowski, Kamil; Kućko, Agata; Świdziński, Michał; de Dios Alché, Juan; Nowakowska, Anna; Kopcewicz, Jan

2016-11-01

Flower abscission is a highly regulated developmental process activated in response to exogenous (e.g. changing environmental conditions) and endogenous stimuli (e.g. phytohormones). Ethylene (ET) and abscisic acid (ABA) are very effective stimulators of flower abortion in Lupinus luteus, which is a widely cultivated species in Poland, Australia and Mediterranean countries. In this paper, we show that artificial activation of abscission by flower removal caused an accumulation of ABA in the abscission zone (AZ). Moreover, the blocking of that phytohormone's biosynthesis by NDGA (nordihydroguaiaretic acid) decreased the number of abscised flowers. However, the application of NBD - an inhibitor of ET action - reversed the stimulatory effect of ABA on flower abscission, indicating that ABA itself is not sufficient to turn on the organ separation. Our analysis revealed that exogenous ABA significantly accelerated the transcriptional activity of the ET biosynthesis genes ACC synthase (LlACS) and oxidase (LlACO), and moreover, strongly increased the level of 1-aminocyclopropane-1-carboxylic acid (ACC) - ET precursor, which was specifically localized within AZ cells. We cannot exclude the possibility that ABA mediates flower abscission processes by enhancing the ET biosynthesis rate. The findings of our study will contribute to the overall basic knowledge on the phytohormone-regulated generative organs abscission in L. luteus. Copyright © 2016 Elsevier GmbH. All rights reserved.

QuEChERS-based extraction procedure for multifamily analysis of phytohormones in vegetables by UHPLC-MS/MS.

PubMed

Flores, María Isabel Alarcón; Romero-González, Roberto; Frenich, Antonia Garrido; Vidal, José Luis Martínez

2011-07-01

A new method has been developed and validated for the simultaneous analysis of different phytohormones (auxins, cytokinins and gibberellins) in vegetables. The compounds were extracted using a QuEChERS-based method (acronym of quick, easy, cheap, effective, rugged and safe). The separation and determination of the selected phytohormones were carried out by ultra high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS), using electrospray ionization source (ESI) in positive and negative ion modes. The method was validated and mean recoveries were evaluated at three concentration levels (50, 100 and 250 μg/kg), ranging from 75 to 110% at the three levels assayed. Intra- and interday precisions, expressed as relative standard deviations (RSDs), were lower than 20 and 25%, respectively. Limits of quantification (LOQs) were equal or lower than 10 μg/kg. The developed procedure was applied to seven courgette samples, and naphthylacetic acid, naphthylacetamide and benzyladenine were found in some of the analysed samples. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Analysis of the transcriptional responses in inflorescence buds of Jatropha curcas exposed to cytokinin treatment.

PubMed

Chen, Mao-Sheng; Pan, Bang-Zhen; Wang, Gui-Juan; Ni, Jun; Niu, Longjian; Xu, Zeng-Fu

2014-11-30

Jatropha curcas L. is a potential biofuel plant. Application of exogenous cytokinin (6-benzyladenine, BA) on its inflorescence buds can significantly increase the number of female flowers, thereby improving seed yield. To investigate which genes and signal pathways are involved in the response to cytokinin in J. curcas inflorescence buds, we monitored transcriptional activity in inflorescences at 0, 3, 12, 24, and 48 h after BA treatment using a microarray. We detected 5,555 differentially expressed transcripts over the course of the experiment, which could be grouped into 12 distinct temporal expression patterns. We also identified 31 and 131 transcripts in J. curcas whose homologs in model plants function in flowering and phytohormonal signaling pathways, respectively. According to the transcriptional analysis of genes involved in flower development, we hypothesized that BA treatment delays floral organ formation by inhibiting the transcription of the A, B and E classes of floral organ-identity genes, which would allow more time to generate more floral primordia in inflorescence meristems, thereby enhancing inflorescence branching and significantly increasing flower number per inflorescence. BA treatment might also play an important role in maintaining the flowering signals by activating the transcription of GIGANTEA (GI) and inactivating the transcription of CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1) and TERMINAL FLOWER 1b (TFL1b). In addition, exogenous cytokinin treatment could regulate the expression of genes involved in the metabolism and signaling of other phytohormones, indicating that cytokinin and other phytohormones jointly regulate flower development in J. curcas inflorescence buds. Our study provides a framework to better understand the molecular mechanisms underlying changes in flowering traits in response to cytokinin treatment in J. curcas inflorescence buds. The results provide valuable information related to the mechanisms of cross-talk among multiple phytohormone signaling pathways in woody plants.

Cis- and trans-zeatin differentially modulate plant immunity.

PubMed

Großkinsky, Dominik K; Edelsbrunner, Kerstin; Pfeifhofer, Hartwig; van der Graaff, Eric; Roitsch, Thomas

2013-07-01

Phytohormones are essential regulators of various processes in plant growth and development. Several phytohormones are also known to regulate plant responses to environmental stress and pathogens. Only recently, cytokinins have been demonstrated to play an important role in plant immunity. Increased levels of cytokinins such as trans-zeatin, which are considered highly active, induced resistance against mainly (hemi)biotrophic pathogens in different plant species. In contrast, cis-zeatin is commonly regarded as a cytokinin exhibiting low or no activity. Here we comparatively study the impact of both zeatin isomers on the infection of Nicotiana tabacum by the (hemi)biotrophic microbial pathogen Pseudomonas syringae. We demonstrate a biological effect of cis-zeatin and a differential effect of the two zeatin isomers on symptom development, defense responses and bacterial multiplication.

Azospirillum: benefits that go far beyond biological nitrogen fixation.

PubMed

Fukami, Josiane; Cerezini, Paula; Hungria, Mariangela

2018-05-04

The genus Azospirillum comprises plant-growth-promoting bacteria (PGPB), which have been broadly studied. The benefits to plants by inoculation with Azospirillum have been primarily attributed to its capacity to fix atmospheric nitrogen, but also to its capacity to synthesize phytohormones, in particular indole-3-acetic acid. Recently, an increasing number of studies has attributed an important role of Azospirillum in conferring to plants tolerance of abiotic and biotic stresses, which may be mediated by phytohormones acting as signaling molecules. Tolerance of biotic stresses is controlled by mechanisms of induced systemic resistance, mediated by increased levels of phytohormones in the jasmonic acid/ethylene pathway, independent of salicylic acid (SA), whereas in the systemic acquired resistance-a mechanism previously studied with phytopathogens-it is controlled by intermediate levels of SA. Both mechanisms are related to the NPR1 protein, acting as a co-activator in the induction of defense genes. Azospirillum can also promote plant growth by mechanisms of tolerance of abiotic stresses, named as induced systemic tolerance, mediated by antioxidants, osmotic adjustment, production of phytohormones, and defense strategies such as the expression of pathogenesis-related genes. The study of the mechanisms triggered by Azospirillum in plants can help in the search for more-sustainable agricultural practices and possibly reveal the use of PGPB as a major strategy to mitigate the effects of biotic and abiotic stresses on agricultural productivity.

Phytohormones and Beneficial Microbes: Essential Components for Plants to Balance Stress and Fitness

PubMed Central

Egamberdieva, Dilfuza; Wirth, Stephan J.; Alqarawi, Abdulaziz A.; Abd_Allah, Elsayed F.; Hashem, Abeer

2017-01-01

Plants are subjected to various abiotic stresses, such as drought, extreme temperature, salinity, and heavy metals. Abiotic stresses have negative impact on the physiology and morphology of plants through defects in the genetic regulation of cellular pathways. Plants employ several tolerance mechanisms and pathways to avert the effects of stresses that are triggered whenever alterations in metabolism are encountered. Phytohormones are among the most important growth regulators; they are known for having a prominent impact on plant metabolism, and additionally, they play a vital role in the stimulation of plant defense response mechanisms against stresses. Exogenous phytohormone supplementation has been adopted to improve growth and metabolism under stress conditions. Recent investigations have shown that phytohormones produced by root-associated microbes may prove to be important metabolic engineering targets for inducing host tolerance to abiotic stresses. Phytohormone biosynthetic pathways have been identified using several genetic and biochemical methods, and numerous reviews are currently available on this topic. Here, we review current knowledge on the function of phytohormones involved in the improvement of abiotic stress tolerance and defense response in plants exposed to different stressors. We focus on recent successes in identifying the roles of microbial phytohormones that induce stress tolerance, especially in crop plants. In doing so, this review highlights important plant morpho-physiological traits that can be exploited to identify the positive effects of phytohormones on stress tolerance. This review will therefore be helpful to plant physiologists and agricultural microbiologists in designing strategies and tools for the development of broad spectrum microbial inoculants supporting sustainable crop production under hostile environments. PMID:29163398

Phytohormone mediation of interactions between herbivores and plant pathogens.

PubMed

Lazebnik, Jenny; Frago, Enric; Dicke, Marcel; van Loon, Joop J A

2014-07-01

Induced plant defenses against either pathogens or herbivore attackers are regulated by phytohormones. These phytohormones are increasingly recognized as important mediators of interactions between organisms associated with plants. In this review, we discuss the role of plant defense hormones in sequential tri-partite interactions among plants, pathogenic microbes, and herbivorous insects, based on the most recent literature. We discuss the importance of pathogen trophic strategy in the interaction with herbivores that exhibit different feeding modes. Plant resistance mechanisms also affect plant quality in future interactions with attackers. We discuss exemplary evidence for the hypotheses that (i) biotrophic pathogens can facilitate chewing herbivores, unless plants exhibit effector-triggered immunity, but (ii) facilitate or inhibit phloem feeders. (iii) Necrotrophic pathogens, on the other hand, can inhibit both phloem feeders and chewers. We also propose herbivore feeding mode as predictor of effects on pathogens of different trophic strategies, providing evidence for the hypotheses that (iv) phloem feeders inhibit pathogen attack by increasing SA induction, whereas (v) chewing herbivores tend not to affect necrotrophic pathogens, while they may either inhibit or facilitate biotrophic pathogens. Putting these hypotheses to the test will increase our understanding of phytohormonal regulation of plant defense to sequential attack by plant pathogens and insect herbivores. This will provide valuable insight into plant-mediated ecological interactions among members of the plant-associated community.

Survey of Genes Involved in Biosynthesis, Transport, and Signaling of Phytohormones with Focus on Solanum lycopersicum

PubMed Central

Simm, Stefan; Scharf, Klaus-Dieter; Jegadeesan, Sridharan; Chiusano, Maria Luisa; Firon, Nurit; Schleiff, Enrico

2016-01-01

Phytohormones control the development and growth of plants, as well as their response to biotic and abiotic stress. The seven most well-studied phytohormone classes defined today are as follows: auxins, ethylene, cytokinin, abscisic acid, jasmonic acid, gibberellins, and brassinosteroids. The basic principle of hormone regulation is conserved in all plants, but recent results suggest adaptations of synthesis, transport, or signaling pathways to the architecture and growth environment of different plant species. Thus, we aimed to define the extent to which information from the model plant Arabidopsis thaliana is transferable to other plants such as Solanum lycopersicum. We extracted the co-orthologues of genes coding for major pathway enzymes in A. thaliana from the translated genomes of 12 species from the clade Viridiplantae. Based on predicted domain architecture and localization of the identified proteins from all 13 species, we inspected the conservation of phytohormone pathways. The comparison was complemented by expression analysis of (co-) orthologous genes in S. lycopersicum. Altogether, this information allowed the assignment of putative functional equivalents between A. thaliana and S. lycopersicum but also pointed to some variations between the pathways in eudicots, monocots, mosses, and green algae. These results provide first insights into the conservation of the various phytohormone pathways between the model system A. thaliana and crop plants such as tomato. We conclude that orthologue prediction in combination with analysis of functional domain architecture and intracellular localization and expression studies are sufficient tools to transfer information from model plants to other plant species. Our results support the notion that hormone synthesis, transport, and response for most part of the pathways are conserved, and species-specific variations can be found. PMID:27695302

Response difference of transgenic and conventional rice (Oryza sativa) to nanoparticles (γFe₂O₃).

PubMed

Gui, Xin; Deng, Yingqing; Rui, Yukui; Gao, Binbin; Luo, Wenhe; Chen, Shili; Nhan, Le Van; Li, Xuguang; Liu, Shutong; Han, Yaning; Liu, Liming; Xing, Baoshan

2015-11-01

Nanoparticles (NPs) are an increasingly common contaminant in agro-environments, and their potential effect on genetically modified (GM) crops has been largely unexplored. GM crop exposure to NPs is likely to increase as both technologies develop. To better understand the implications of nanoparticles on GM plants in agriculture, we performed a glasshouse study to quantify the uptake of Fe2O3 NPs on transgenic and non-transgenic rice plants. We measured nutrient concentrations, biomass, enzyme activity, and the concentration of two phytohormones, abscisic acid (ABA) and indole-3-acetic acid (IAA), and malondialdehyde (MDA). Root phytohormone inhibition was positively correlated with Fe2O3 NP concentrations, indicating that Fe2O3 had a significant influence on the production of these hormones. The activities of antioxidant enzymes were significantly higher as a factor of low Fe2O3 NP treatment concentration and significantly lower at high NP concentrations, but only among transgenic plants. There was also a positive correlation between the treatment concentration of Fe2O3 and iron accumulation, and the magnitude of this effect was greatest among non-transgenic plants. The differences in root phytohormone production and antioxidant enzyme activity between transgenic and non-transgenic rice plants in vivo suggests that GM crops may react to NP exposure differently than conventional crops. It is the first study of NPs that may have an impact on GM crops, and a realistic significance for food security and food safety.

[Isolation, identification and characterization of ACC deaminase-containing endophytic bacteria from halophyte Suaeda salsa].

PubMed

Teng, Songshan; Liu, Yanping; Zhao, Lei

2010-11-01

We Isolated and characterized 1-aminocyclopropane-1-carboxylate (ACC) deaminase-containing endophytic bacteria from halophyte Suaeda salsa to understand the interactions between endophytes and halophyte. ACC deaminase-containing endophytic bacteria were isolated from root, stalk and leaf of Suaeda salsa and were identified based on morphological, physiological-biochemical properties, API and 16S rRNA sequence analysis. Isolates were evaluated for their ACC deaminase, antifungal, protease activity, siderophores and phytohormones, such as indole-3-acetic acid, gibberellic acid and abscisic acid production, as well as atmospheric nitrogen fixation and phosphate solubilization. Four ACC deaminase-containing endophytic bacteria strains named as LP11, SS12, TW1 and TW2 were isolated and identified as Pseudomonas oryzihabitans, Pseudomonas sp., Pantoea agglomerans and Pseudomonas putida respectively. All the strains possessed the phosphate-solubilizing ability and could produce siderophores and phytohormones more or less. None of them could fix atmospheric nitrogen or produce protease. Only strain SS12 showed antagonism against two phytopathogenic fungi viz Fusarium oxysporum f. sp. conglutinans and F. oxysporum f. sp. cucumerinum. ACC deaminase-containing endophytic bacteria of Pseudomonas sp. and Pantoea sp. isolated from halophyte Suaeda salsa have abundant biological characteristics related to plant growth promotion, stress homeostasis regulation and biocontrol activity.

Naturally induced secretions of the potato cyst nematode co-stimulate the proliferation of both tobacco leaf protoplasts and human peripheral blood mononuclear cells.

PubMed

Goverse, A; Rouppe van der Voort, J; Roppe van der Voort, C; Kavelaars, A; Smant, G; Schots, A; Bakker, J; Helder, J

1999-10-01

Naturally induced secretions from infective juveniles of the potato cyst nematode Globodera rostochiensis co-stimulate the proliferation of tobacco leaf protoplasts in the presence of the synthetic phytohormones alpha-naphthaleneacetic acid (NAA) and 6-benzylaminopurine (BAP). With the use of a protoplast-based bioassay, a low-molecular-weight peptide(s) (< 3 kDa) was shown to be responsible for the observed effect. This mitogenic oligopeptide(s) is functionally dissimilar to auxin and cytokinin and, in addition, it does not change the sensitivity of the protoplasts toward these phytohormones. In combination with the mitogen phytohemagglutinin (PHA), cyst nematode secretions also co-stimulated mitogenesis in human peripheral blood mononuclear cells (PBMC). The stimulation of plant cells isolated from nontarget tissue--these nematodes normally invade the roots of potato plants--suggests the activation of a general signal transduction mechanism(s) by an oligopeptide(s) secreted by the nematode. Whether a similar oligopeptide-induced mechanism underlies human PBMC activation remains to be investigated. Reactivation of the cell cycle is a crucial event in feeding cell formation by cyst nematodes. The secretion of a mitogenic low-molecular-weight peptide(s) by infective juveniles of the potato cyst nematode could contribute to the redifferentiation of plant cells into such a feeding cell.

Growth-promoting Sphingomonas paucimobilis ZJSH1 associated with Dendrobium officinale through phytohormone production and nitrogen fixation

PubMed Central

Yang, Suijuan; Zhang, Xinghai; Cao, Zhaoyun; Zhao, Kaipeng; Wang, Sai; Chen, Mingxue; Hu, Xiufang

2014-01-01

Growth-promoting Sphingomonas paucimobilis ZJSH1, associated with Dendrobium officinale, a traditional Chinese medicinal plant, was characterized. At 90 days post-inoculation, strain ZJSH1 significantly promoted the growth of D. officinale seedlings, with increases of stems by 8.6% and fresh weight by 7.5%. Interestingly, the polysaccharide content extracted from the inoculated seedlings was 0.6% higher than that of the control. Similar growth promotion was observed with the transplants inoculated with strain ZJSH1. The mechanism of growth promotion was attributed to a combination of phytohormones and nitrogen fixation. Strain ZJSH1 was found using the Kjeldahl method to have a nitrogen fixation activity of 1.15 mg l−1, which was confirmed by sequencing of the nifH gene. Using high-performance liquid chromatography-mass spectrometry, strain ZJSH1 was found to produce various phytohormones, including salicylic acid (SA), indole-3-acetic acid (IAA), Zeatin and abscisic acid (ABA). The growth curve showed that strain ZJSH1 grew well in the seedlings, especially in the roots. Accordingly, much higher contents of SA, ABA, IAA and c-ZR were detected in the inoculated seedlings, which may play roles as both phytohormones and ‘Systemic Acquired Resistance’ drivers. Nitrogen fixation and secretion of plant growth regulators (SA, IAA, Zeatin and ABA) endow S. paucimobilis ZJSH1 with growth-promoting properties, which provides a potential for application in the commercial growth of D. officinale. PMID:25142808

Genome-wide analysis of the GH3 family in apple (Malus × domestica)

PubMed Central

2013-01-01

Background Auxin plays important roles in hormone crosstalk and the plant’s stress response. The auxin-responsive Gretchen Hagen3 (GH3) gene family maintains hormonal homeostasis by conjugating excess indole-3-acetic acid (IAA), salicylic acid (SA), and jasmonic acids (JAs) to amino acids during hormone- and stress-related signaling pathways. With the sequencing of the apple (Malus × domestica) genome completed, it is possible to carry out genomic studies on GH3 genes to indentify candidates with roles in abiotic/biotic stress responses. Results Malus sieversii Roem., an apple rootstock with strong drought tolerance and the ancestral species of cultivated apple species, was used as the experimental material. Following genome-wide computational and experimental identification of MdGH3 genes, we showed that MdGH3s were differentially expressed in the leaves and roots of M. sieversii and that some of these genes were significantly induced after various phytohormone and abiotic stress treatments. Given the role of GH3 in the negative feedback regulation of free IAA concentration, we examined whether phytohormones and abiotic stresses could alter the endogenous auxin level. By analyzing the GUS activity of DR5::GUS-transformed Arabidopsis seedlings, we showed that ABA, SA, salt, and cold treatments suppressed the auxin response. These findings suggest that other phytohormones and abiotic stress factors might alter endogenous auxin levels. Conclusion Previous studies showed that GH3 genes regulate hormonal homeostasis. Our study indicated that some GH3 genes were significantly induced in M. sieversii after various phytohormone and abiotic stress treatments, and that ABA, SA, salt, and cold treatments reduce the endogenous level of axuin. Taken together, this study provides evidence that GH3 genes play important roles in the crosstalk between auxin, other phytohormones, and the abiotic stress response by maintaining auxin homeostasis. PMID:23638690

Biology of the eremophilanes produced by Drechslera gigantea

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

Bunkers, G.J.

1989-01-01

A procedure, using high performance liquid chromatography to quantify eremophilane levels in culture filtrates of D. gigantea was developed. This procedure was used to study eremophilane production by D. gigantea under different cultural conditions. The structure-activity relationships of the eremophilanes were investigated using three different bioassays. No distinct functional groups or structural characteristics could be correlated to activity. However, in all three bioassays, the eremophilanes with the higher oxidation states were generally less active. To determine the mode of action, the effects of eremophilanes on the physiology of the plant were studied. Eremophilane bioactivities mimic the activity of known phytohormones.more » Comparative studies indicated that these activities seem not to be associated with induction of known phytohormones but are inherent properties of the eremophilane molecules. The eremophilanes were shown to inhibit protein synthesis both in vitro and in vivo. The proposed mode of action of the eremophilanes is inhibition of protein synthesis. Finally, the fate of the eremophilanes in planta was investigated. ({sup 14}C)-petasol was applied to detached oat leaves (Avena sativa cv. Park) and the radiolabel was traced.« less

First draft genome sequencing of indole acetic acid producing and plant growth promoting fungus Preussia sp. BSL10.

PubMed

Khan, Abdul Latif; Asaf, Sajjad; Khan, Abdur Rahim; Al-Harrasi, Ahmed; Al-Rawahi, Ahmed; Lee, In-Jung

2016-05-10

Preussia sp. BSL10, family Sporormiaceae, was actively producing phytohormone (indole-3-acetic acid) and extra-cellular enzymes (phosphatases and glucosidases). The fungus was also promoting the growth of arid-land tree-Boswellia sacra. Looking at such prospects of this fungus, we sequenced its draft genome for the first time. The Illumina based sequence analysis reveals an approximate genome size of 31.4Mbp for Preussia sp. BSL10. Based on ab initio gene prediction, total 32,312 coding sequences were annotated consisting of 11,967 coding genes, pseudogenes, and 221 tRNA genes. Furthermore, 321 carbohydrate-active enzymes were predicted and classified into many functional families. Copyright © 2016 Elsevier B.V. All rights reserved.

Soilless plant growth media influence the efficacy of phytohormones and phytohormone inhibitors.

PubMed

Best, Norman B; Hartwig, Thomas; Budka, Joshua S; Bishop, Brandon J; Brown, Elliot; Potluri, Devi P V; Cooper, Bruce R; Premachandra, Gnanasiri S; Johnston, Cliff T; Schulz, Burkhard

2014-01-01

Plant growth regulators, such as hormones and their respective biosynthesis inhibitors, are effective tools to elucidate the physiological function of phytohormones in plants. A problem of chemical treatments, however, is the potential for interaction of the active compound with the growth media substrate. We studied the interaction and efficacy of propiconazole, a potent and specific inhibitor of brassinosteroid biosynthesis, with common soilless greenhouse growth media for rice, sorghum, and maize. Many of the tested growth media interacted with propiconazole reducing its efficacy up to a hundred fold. To determine the molecular interaction of inhibitors with media substrates, Fourier Transform Infrared Spectroscopy and sorption isotherm analysis was applied. While mica clay substrates absorbed up to 1.3 mg of propiconazole per g substrate, calcined clays bound up to 12 mg of propiconazole per g substrate. The efficacy of the gibberellic acid biosynthesis inhibitor, uniconazole, and the most active brassinosteroid, brassinolide, was impacted similarly by the respective substrates. Conversely, gibberellic acid showed no distinct growth response in different media. Our results suggest that the reduction in efficacy of propiconazole, uniconazole, and brassinolide in bioassays when grown in calcined clay is caused by hydrophobic interactions between the plant growth regulators and the growth media. This was further confirmed by experiments using methanol-water solvent mixes with higher hydrophobicity values, which reduce the interaction of propiconazole and calcined clay.

High-power LEDs for plant cultivation

NASA Astrophysics Data System (ADS)

Tamulaitis, Gintautas; Duchovskis, Pavelas; Bliznikas, Zenius; Breive, Kestutis; Ulinskaite, Raimonda; Brazaityte, Ausra; Novickovas, Algirdas; Zukauskas, Arturas; Shur, Michael S.

2004-10-01

We report on high-power solid-state lighting facility for cultivation of greenhouse vegetables and on the results of the study of control of photosynthetic activity and growth morphology of radish and lettuce imposed by variation of the spectral composition of illumination. Experimental lighting modules (useful area of 0.22 m2) were designed based on 4 types of high-power light-emitting diodes (LEDs) with emission peaked in red at the wavelengths of 660 nm and 640 nm (predominantly absorbed by chlorophyll a and b for photosynthesis, respectively), in blue at 455 nm (phototropic function), and in far-red at 735 nm (important for photomorphology). Morphological characteristics, chlorophyll and phytohormone concentrations in radish and lettuce grown in phytotron chambers under lighting with different spectral composition of the LED-based illuminator and under illumination by high pressure sodium lamps with an equivalent photosynthetic photon flux density were compared. A well-balanced solid-state lighting was found to enhance production of green mass and to ensure healthy morphogenesis of plants compared to those grown using conventional lighting. We observed that the plant morphology and concentrations of morphologically active phytohormones is strongly affected by the spectral composition of light in the red region. Commercial application of the LED-based illumination for large-scale plant cultivation is discussed. This technology is favorable from the point of view of energy consumption, controllable growth, and food safety but is hindered by high cost of the LEDs. Large scale manufacturing of high-power red AlInGaP-based LEDs emitting at 650 nm and a further decrease of the photon price for the LEDs emitting in the vicinity of the absorption peak of chlorophylls have to be achieved to promote horticulture applications.

Simultaneous analysis of different classes of phytohormones in coconut (Cocos nucifera L.) water using high-performance liquid chromatography and liquid chromatography-tandem mass spectrometry after solid-phase extraction.

PubMed

Ma, Zhen; Ge, Liya; Lee, Anna S Y; Yong, Jean Wan Hong; Tan, Swee Ngin; Ong, Eng Shi

2008-03-10

Coconut (Cocos nucifera L.) water, which contains many uncharacterized phytohormones is extensively used as a growth promoting supplement in plant tissue culture. In this paper, a high-performance liquid chromatography (HPLC) method was developed for the simultaneous determination of various classes phytohormones, including indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), abscisic acid (ABA), gibberellic acid (GA), zeatin (Z), N(6)-benzyladenine (BA), alpha-naphthaleneacetic acid (NAA) and 2,4-dichlorophenoxyacetic acid (2,4-D) in young coconut water (CW). The analysis was carried out using a reverse-phase HPLC gradient elution, with an aqueous mobile phase (containing 0.1% formic acid, pH adjusted to 3.2 with triethylamine (TEA)) modified by methanol, and solute detection made at 265 nm wavelength. The method was validated for specificity, quantification, accuracy and precision. After preconcentration of putative endogenous phytohormones in CW using C(18) solid-phase extraction (SPE) cartridges, the HPLC method was able to screen for putative endogenous phytohormones present in CW. Finally, the identities of the putative phytohormones present in CW were further confirmed using independent liquid chromatography-tandem mass spectrometry (LC-MS/MS) equipped with an electrospray ionization (ESI) interface.

Gene Expression Profiling of Development and Anthocyanin Accumulation in Kiwifruit (Actinidia chinensis) Based on Transcriptome Sequencing

PubMed Central

Zeng, Shaohua; Xiao, Gong; Wang, Gan; Wang, Ying; Peng, Ming; Huang, Hongwen

2015-01-01

Red-fleshed kiwifruit (Actinidia chinensis Planch. ‘Hongyang’) is a promising commercial cultivar due to its nutritious value and unique flesh color, derived from vitamin C and anthocyanins. In this study, we obtained transcriptome data of ‘Hongyang’ from seven developmental stages using Illumina sequencing. We mapped 39–54 million reads to the recently sequenced kiwifruit genome and other databases to define gene structure, to analyze alternative splicing, and to quantify gene transcript abundance at different developmental stages. The transcript profiles throughout red kiwifruit development were constructed and analyzed, with a focus on the biosynthesis and metabolism of compounds such as phytohormones, sugars, starch and L-ascorbic acid, which are indispensable for the development and formation of quality fruit. Candidate genes for these pathways were identified through MapMan and phylogenetic analysis. The transcript levels of genes involved in sucrose and starch metabolism were consistent with the change in soluble sugar and starch content throughout kiwifruit development. The metabolism of L-ascorbic acid was very active, primarily through the L-galactose pathway. The genes responsible for the accumulation of anthocyanin in red kiwifruit were identified, and their expression levels were investigated during kiwifruit development. This survey of gene expression during kiwifruit development paves the way for further investigation of the development of this uniquely colored and nutritious fruit and reveals which factors are needed for high quality fruit formation. This transcriptome data and its analysis will be useful for improving kiwifruit genome annotation, for basic fruit molecular biology research, and for kiwifruit breeding and improvement. PMID:26301713

Exogenous Classic Phytohormones Have Limited Regulatory Effects on Fructan and Primary Carbohydrate Metabolism in Perennial Ryegrass (Lolium perenne L.)

PubMed Central

Gasperl, Anna; Morvan-Bertrand, Annette; Prud'homme, Marie-Pascale; van der Graaff, Eric; Roitsch, Thomas

2016-01-01

Fructans are polymers of fructose and one of the main constituents of water-soluble carbohydrates in forage grasses and cereal crops of temperate climates. Fructans are involved in cold and drought resistance, regrowth following defoliation and early spring growth, seed filling, have beneficial effects on human health and are used for industrial processes. Perennial ryegrass (Lolium perenne L.) serves as model species to study fructan metabolism. Fructan metabolism is under the control of both synthesis by fructosyltransferases (FTs) and breakdown through fructan exohydrolases (FEHs). The accumulation of fructans can be triggered by high sucrose levels and abiotic stress conditions such as drought and cold stress. However, detailed studies on the mechanisms involved in the regulation of fructan metabolism are scarce. Since different phytohormones, especially abscisic acid (ABA), are known to play an important role in abiotic stress responses, the possible short term regulation of the enzymes involved in fructan metabolism by the five classical phytohormones was investigated. Therefore, the activities of enzymes involved in fructan synthesis and breakdown, the expression levels for the corresponding genes and levels for water-soluble carbohydrates were determined following pulse treatments with ABA, auxin (AUX), ethylene (ET), gibberellic acid (GA), or kinetin (KIN). The most pronounced fast effects were a transient increase of FT activities by AUX, KIN, ABA, and ET, while minor effects were evident for 1-FEH activity with an increased activity in response to KIN and a decrease by GA. Fructan and sucrose levels were not affected. This observed discrepancy demonstrates the importance of determining enzyme activities to obtain insight into the physiological traits and ultimately the plant phenotype. The comparative analyses of activities for seven key enzymes of primary carbohydrate metabolism revealed no co-regulation between enzymes of the fructan and sucrose pool. PMID:26834764

Pollination: a key event controlling the expression of genes related to phytohormone biosynthesis during grapevine berry formation.

PubMed

Kühn, Nathalie; Arce-Johnson, Patricio

2012-01-01

Berry formation is the process of ovary conversion into a functional fruit, and is characterized by abrupt changes in the content of several phytohormones, associated with pollination and fertilization. Much effort has been made in order to improve our understanding of berry development, particularly from veraison to post-harvest time. However, the period of berry formation has been poorly investigated, despite its importance. Phytohormones are involved in the control of fruit formation; hence it is important to understand the regulation of their content at this stage. Grapevine is an excellent fleshy-fruit plant model since its fruits have particularities that differentiate them from those of commonly studied organisms. For instance, berries are prepared to cope with stress by producing several antioxidants and they are non-climacteric fruits. Also its genome is fully sequenced, which allows to identify genes involved in developmental processes. In grapevine, no link has been established between pollination and phytohormone biosynthesis, until recently. Here we highlight relevant findings regarding pollination effect on gene expression related to phytohormone biosynthesis, and present unpublished results showing how quickly this effect is achieved.

Detection of phytohormones in temperate forest fungi predicts consistent abscisic acid production and a common pathway for cytokinin biosynthesis.

PubMed

Morrison, Erin N; Knowles, Sarah; Hayward, Allison; Thorn, R Greg; Saville, Barry J; Emery, R J N

2015-01-01

The phytohormones, abscisic acid and cytokinin, once were thought to be present uniquely in plants, but increasing evidence suggests that these hormones are present in a wide variety of organisms. Few studies have examined fungi for the presence of these "plant" hormones or addressed whether their levels differ based on the nutrition mode of the fungus. This study examined 20 temperate forest fungi of differing nutritional modes (ectomycorrhizal, wood-rotting, saprotrophic). Abscisic acid and cytokinin were present in all fungi sampled; this indicated that the sampled fungi have the capacity to synthesize these two classes of phytohormones. Of the 27 cytokinins analyzed by HPLC-ESI MS/MS, seven were present in all fungi sampled. This suggested the existence of a common cytokinin metabolic pathway in fungi that does not vary among different nutritional modes. Predictions regarding the source of isopentenyl, cis-zeatin and methylthiol CK production stemming from the tRNA degradation pathway among fungi are discussed. © 2015 by The Mycological Society of America.

A special pair of phytohormones controls excitability, slow closure, and external stomach formation in the Venus flytrap

PubMed Central

Escalante-Pérez, María; Krol, Elzbieta; Stange, Annette; Geiger, Dietmar; Al-Rasheid, Khaled A. S.; Hause, Bettina; Neher, Erwin; Hedrich, Rainer

2011-01-01

Venus flytrap's leaves can catch an insect in a fraction of a second. Since the time of Charles Darwin, scientists have struggled to understand the sensory biology and biomechanics of this plant, Dionaea muscipula. Here we show that insect-capture of Dionaea traps is modulated by the phytohormone abscisic acid (ABA) and jasmonates. Water-stressed Dionaea, as well as those exposed to the drought-stress hormone ABA, are less sensitive to mechanical stimulation. In contrast, application of 12-oxo-phytodienoic acid (OPDA), a precursor of the phytohormone jasmonic acid (JA), the methyl ester of JA (Me-JA), and coronatine (COR), the molecular mimic of the isoleucine conjugate of JA (JA-Ile), triggers secretion of digestive enzymes without any preceding mechanical stimulus. Such secretion is accompanied by slow trap closure. Under physiological conditions, insect-capture is associated with Ca2+ signaling and a rise in OPDA, Apparently, jasmonates bypass hapto-electric processes associated with trap closure. However, ABA does not affect OPDA-dependent gland activity. Therefore, signals for trap movement and secretion seem to involve separate pathways. Jasmonates are systemically active because application to a single trap induces secretion and slow closure not only in the given trap but also in all others. Furthermore, formerly touch-insensitive trap sectors are converted into mechanosensitive ones. These findings demonstrate that prey-catching Dionaea combines plant-specific signaling pathways, involving OPDA and ABA with a rapidly acting trigger, which uses ion channels, action potentials, and Ca2+ signals. PMID:21896747

A special pair of phytohormones controls excitability, slow closure, and external stomach formation in the Venus flytrap.

PubMed

Escalante-Pérez, María; Krol, Elzbieta; Stange, Annette; Geiger, Dietmar; Al-Rasheid, Khaled A S; Hause, Bettina; Neher, Erwin; Hedrich, Rainer

2011-09-13

Venus flytrap's leaves can catch an insect in a fraction of a second. Since the time of Charles Darwin, scientists have struggled to understand the sensory biology and biomechanics of this plant, Dionaea muscipula. Here we show that insect-capture of Dionaea traps is modulated by the phytohormone abscisic acid (ABA) and jasmonates. Water-stressed Dionaea, as well as those exposed to the drought-stress hormone ABA, are less sensitive to mechanical stimulation. In contrast, application of 12-oxo-phytodienoic acid (OPDA), a precursor of the phytohormone jasmonic acid (JA), the methyl ester of JA (Me-JA), and coronatine (COR), the molecular mimic of the isoleucine conjugate of JA (JA-Ile), triggers secretion of digestive enzymes without any preceding mechanical stimulus. Such secretion is accompanied by slow trap closure. Under physiological conditions, insect-capture is associated with Ca(2+) signaling and a rise in OPDA, Apparently, jasmonates bypass hapto-electric processes associated with trap closure. However, ABA does not affect OPDA-dependent gland activity. Therefore, signals for trap movement and secretion seem to involve separate pathways. Jasmonates are systemically active because application to a single trap induces secretion and slow closure not only in the given trap but also in all others. Furthermore, formerly touch-insensitive trap sectors are converted into mechanosensitive ones. These findings demonstrate that prey-catching Dionaea combines plant-specific signaling pathways, involving OPDA and ABA with a rapidly acting trigger, which uses ion channels, action potentials, and Ca(2+) signals.

Genome-wide analysis reveals phytohormone action during cassava storage root initiation.

PubMed

Sojikul, Punchapat; Saithong, Treenut; Kalapanulak, Saowalak; Pisuttinusart, Nuttapat; Limsirichaikul, Siripan; Tanaka, Maho; Utsumi, Yoshinori; Sakurai, Tetsuya; Seki, Motoaki; Narangajavana, Jarunya

2015-08-01

Development of storage roots is a process associated with a phase change from cell division and elongation to radial growth and accumulation of massive amounts of reserve substances such as starch. Knowledge of the regulation of cassava storage root formation has accumulated over time; however, gene regulation during the initiation and early stage of storage root development is still poorly understood. In this study, transcription profiling of fibrous, intermediate and storage roots at eight weeks old were investigated using a 60-mer-oligo microarray. Transcription and gene expression were found to be the key regulating processes during the transition stage from fibrous to intermediate roots, while homeostasis and signal transduction influenced regulation from intermediate roots to storage roots. Clustering analysis of significant genes and transcription factors (TF) indicated that a number of phytohormone-related TF were differentially expressed; therefore, phytohormone-related genes were assembled into a network of correlative nodes. We propose a model showing the relationship between KNOX1 and phytohormones during storage root initiation. Exogeneous treatment of phytohormones N (6) -benzylaminopurine and 1-Naphthaleneacetic acid were used to induce the storage root initiation stage and to investigate expression patterns of the genes involved in storage root initiation. The results support the hypothesis that phytohormones are acting in concert to regulate the onset of cassava storage root development. Moreover, MeAGL20 is a factor that might play an important role at the onset of storage root initiation when the root tip becomes swollen.

Expression profiling of marker genes responsive to the defence-associated phytohormones salicylic acid, jasmonic acid and ethylene in Brachypodium distachyon.

PubMed

Kouzai, Yusuke; Kimura, Mamiko; Yamanaka, Yurie; Watanabe, Megumi; Matsui, Hidenori; Yamamoto, Mikihiro; Ichinose, Yuki; Toyoda, Kazuhiro; Onda, Yoshihiko; Mochida, Keiichi; Noutoshi, Yoshiteru

2016-03-02

Brachypodium distachyon is a promising model plants for grasses. Infections of Brachypodium by various pathogens that severely impair crop production have been reported, and the species accordingly provides an alternative platform for investigating molecular mechanisms of pathogen virulence and plant disease resistance. To date, we have a broad picture of plant immunity only in Arabidopsis and rice; therefore, Brachypodium may constitute a counterpart that displays the commonality and uniqueness of defence systems among plant species. Phytohormones play key roles in plant biotic stress responses, and hormone-responsive genes are used to qualitatively and quantitatively evaluate disease resistance responses during pathogen infection. For these purposes, defence-related phytohormone marker genes expressed at time points suitable for defence-response monitoring are needed. Information about their expression profiles over time as well as their response specificity is also helpful. However, useful marker genes are still rare in Brachypodium. We selected 34 candidates for Brachypodium marker genes on the basis of protein-sequence similarity to known marker genes used in Arabidopsis and rice. Brachypodium plants were treated with the defence-related phytohormones salicylic acid, jasmonic acid and ethylene, and their transcription levels were measured 24 and 48 h after treatment. Two genes for salicylic acid, 7 for jasmonic acid and 2 for ethylene were significantly induced at either or both time points. We then focused on 11 genes encoding pathogenesis-related (PR) 1 protein and compared their expression patterns with those of Arabidopsis and rice. Phylogenetic analysis suggested that Brachypodium contains several PR1-family genes similar to rice genes. Our expression profiling revealed that regulation patterns of some PR1 genes as well as of markers identified for defence-related phytohormones are closely related to those in rice. We propose that the Brachypodium immune hormone marker genes identified in this study will be useful to plant pathologists who use Brachypodium as a model pathosystem, because the timing of their transcriptional activation matches that of the disease resistance response. Our results using Brachypodium also suggest that monocots share a characteristic immune system, defined as the common defence system, that is different from that of dicots.

A new look at stress: abscisic acid patterns and dynamics at high-resolution.

PubMed

Jones, Alexander M

2016-04-01

Abscisic acid (ABA) is a key phytohormone promoting abiotic stress tolerance as well as developmental processes such as seed dormancy. A spatiotemporal map of ABA concentrations would greatly advance our understanding of the cell type and timing of ABA action. Organ and tissue-level ABA measurements, as well as indirect in vivo measurements such as cell-specific transcriptional analysis of ABA metabolic enzymes and ABA-responsive promoters, have all contributed to current views of the localization and timing of ABA accumulations. Recently developed Förster resonance energy transfer (FRET) biosensors for ABA that sense ABA levels directly promise to add unprecedented resolution to in vivo ABA spatiotemporal mapping and expand our knowledge of the mechanisms controlling ABA levels in space and time. © 2015 Carnegie Institution for Science New Phytologist © 2015 New Phytologist Trust.

Proteins in phytohormone signaling pathways for abiotic stress in plants

USDA-ARS?s Scientific Manuscript database

Plant hormones and their signaling network systems have an essential role in activating and regulating plant responses to both biotic and abiotic stress factors. This chapter describes proteins that are involved in hormone biosynthesis, long distance and intra-cellular transport, the signaling sensi...

Biosynthetic pathway of the phytohormone auxin in insects and screening of its inhibitors.

PubMed

Suzuki, Hiroyoshi; Yokokura, Junpei; Ito, Tsukasa; Arai, Ryoma; Yokoyama, Chiaki; Toshima, Hiroaki; Nagata, Shinji; Asami, Tadao; Suzuki, Yoshihito

2014-10-01

Insect galls are abnormal plant tissues induced by galling insects. The galls are used for food and habitation, and the phytohormone auxin, produced by the insects, may be involved in their formation. We found that the silkworm, a non-galling insect, also produces an active form of auxin, indole-3-acetic acid (IAA), by de novo synthesis from tryptophan (Trp). A detailed metabolic analysis of IAA using IAA synthetic enzymes from silkworms indicated an IAA biosynthetic pathway composed of a three-step conversion: Trp → indole-3-acetaldoxime → indole-3-acetaldehyde (IAAld) → IAA, of which the first step is limiting IAA production. This pathway was shown to also operate in gall-inducing sawfly. Screening of a chemical library identified two compounds that showed strong inhibitory activities on the conversion step IAAld → IAA. The inhibitors can be efficiently used to demonstrate the importance of insect-synthesized auxin in gall formation in the future. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Effects of phytohormones on growth and DHA production by Thraustochytrium roseum].

PubMed

Wu, Kegang; Chai, Xianghua; Yang, Liansheng

2003-02-01

In this paper, effects of phytohormones on growth and DHA production by Thraustochytrium roseum MF2 were studied. Results showed that phytohormones had significant affect on growth and DHA production by T. roseum MF2. GA could promote the synthesis of DHA, and BA could accelerate the growth of T. roseum MF2, so the combination of GA and BA could increase DHA yield. The maximum DHA yield of 982mg/L was observed with 2mg/L GA and 3mg/L BA in medium.

Calculation and Comparative Analysis of the IR Spectra of Homobrassinolide and (22S,23S)-Homobrassinolide

NASA Astrophysics Data System (ADS)

Andrianov, V. M.; Korolevich, M. V.

2015-09-01

Normal vibrational frequencies and absolute IR band intensities of the biologically active steroid phytohormones homobrassinolide and (22S,23S)-homobrassinolide were calculated in the framework of an original approach that combined classical analysis of normal modes using molecular mechanics with quantum-chemical estimation of the absolute intensities. IR absorption bands were interpreted based on a comparison of the experimental and theoretical absorption spectra. The impact of structural differences in the side chains of these molecules on the formation of their IR spectra in the region 1500-950 cm -1 was estimated.

The effect of phytohormones on the dynamics of protein biosynthesis and enzyme activity in linted and naked cotton seed

USDA-ARS?s Scientific Manuscript database

We determined the effect of exogenous indole-3-acetic acid, a-naphthylene-3-acetic acid and gibberellic acid (GA3) on the enzymatic activity of glucansynthase, peroxidase and cellulase in ovule development of naked L-70 and linted AN-Bayaut-2 cotton (Gossypium hirsutum L.) seeds. We isolated a prote...

Exogenous auxin represses soybean seed germination through decreasing the gibberellin/abscisic acid (GA/ABA) ratio.

PubMed

Shuai, Haiwei; Meng, Yongjie; Luo, Xiaofeng; Chen, Feng; Zhou, Wenguan; Dai, Yujia; Qi, Ying; Du, Junbo; Yang, Feng; Liu, Jiang; Yang, Wenyu; Shu, Kai

2017-10-03

Auxin is an important phytohormone which mediates diverse development processes in plants. Published research has demonstrated that auxin induces seed dormancy. However, the precise mechanisms underlying the effect of auxin on seed germination need further investigation, especially the relationship between auxins and both abscisic acid (ABA) and gibberellins (GAs), the latter two phytohormones being the key regulators of seed germination. Here we report that exogenous auxin treatment represses soybean seed germination by enhancing ABA biosynthesis, while impairing GA biogenesis, and finally decreasing GA 1 /ABA and GA 4 /ABA ratios. Microscope observation showed that auxin treatment delayed rupture of the soybean seed coat and radicle protrusion. qPCR assay revealed that transcription of the genes involved in ABA biosynthetic pathway was up-regulated by application of auxin, while expression of genes involved in GA biosynthetic pathway was down-regulated. Accordingly, further phytohormone quantification shows that auxin significantly increased ABA content, whereas the active GA 1 and GA 4 levels were decreased, resulting insignificant decreases in the ratiosGA 1 /ABA and GA 4 /ABA.Consistent with this, ABA biosynthesis inhibitor fluridone reversed the delayed-germination phenotype associated with auxin treatment, while paclobutrazol, a GA biosynthesis inhibitor, inhibited soybean seed germination. Altogether, exogenous auxin represses soybean seed germination by mediating ABA and GA biosynthesis.

Soybean Seed Development: Fatty Acid and Phytohormone Metabolism and Their Interactions

PubMed Central

Nguyen, Quoc Thien.; Kisiala, Anna; Andreas, Peter; Neil Emery, R.J.; Narine, Suresh

2016-01-01

Vegetable oil utilization is determined by its fatty acid composition. In soybean and other grain crops, during the seed development oil accumulation is important trait for value in food or industrial applications. Seed development is relatively short and sensitive to unfavorable abiotic conditions. These stresses can lead to a numerous undesirable qualitative as well as quantitative changes in fatty acid production. Fatty acid manipulation which targets a higher content of a specific single fatty acid for food or industrial application has gained more attention. Despite several successes in modifying the ratio of endogenous fatty acids in most domesticated oilseed crops, numerous obstacles in FA manipulation of seed maturation are yet to be overcome. Remarkably, connections with plant hormones have not been well studied despite their critical roles in the regulation and promotion of a plethora of processes in plant growth and development. While activities of phytohormones during the reproductive phase have been partially clarified in seed physiology, the biological role of plant hormones in oil accumulation during seed development has not been investigated. In this review seed development and numerous effects of abiotic stresses are discussed. After describing fatty acid and phytohormone metabolism and their interactions, we postulate that the endogenous plant hormones play important roles in fatty acid production in soybean seeds. PMID:27252591

One-pot synthesis of zeolitic imidazolate framework-8/poly (methyl methacrylate-ethyleneglycol dimethacrylate) monolith coating for stir bar sorptive extraction of phytohormones from fruit samples followed by high performance liquid chromatography-ultraviolet detection.

PubMed

You, Linna; He, Man; Chen, Beibei; Hu, Bin

2017-11-17

In this work, zeolitic imidazolate framework-8 (ZIF-8)/poly (methyl methacrylate-ethyleneglycol dimethacrylate) (MMA-EGDMA) composite monolith was in situ synthesized on stir bar by one-pot polymerization. Compared with the neat monolith, ZIF-8/poly(MMA-EGDMA) composite monolith has larger surface area and pore volume. It also exhibits higher extraction efficiency for target phytohormones than poly(MMA-EGDMA) monolith and commercial polyethylene glycol (PEG) coated stir bar. Based on it, a method of ZIF-8/poly(MMA-EGDMA) monolith coated stir bar sorptive extraction (SBSE)-high performance liquid chromatography-ultraviolet detection (HPLC-UV) was established for the analysis of five phytohormones in apple and pear samples. The developed method exhibited low limits of detection (0.11-0.51μg/L), wide linear range (0.5-500μg/L) and good recoveries (82.7-111%), which demonstrated good application potential of the ZIF-8/monolith coated stir bar in trace analysis of organic compounds. Copyright © 2017 Elsevier B.V. All rights reserved.

Antioxidative and antitumor properties of in vitro-cultivated broccoli (Brassica oleracea var. italica).

PubMed

Cakar, Jasmina; Parić, Adisa; Maksimović, Milka; Bajrović, Kasim

2012-02-01

Broccoli [Brassica oleracea L. var. italica Plenck. (Brassicaceae)] contains substantial quantities of bioactive compounds, which are good free radical scavengers and thus might have strong antitumor properties. Enhancing production of plant secondary metabolites could be obtained with phytohormones that have significant effects on the metabolism of secondary metabolites. In that manner, in vitro culture presents good model for manipulation with plant tissues in order to affect secondary metabolite production and thus enhance bioactive properties of plants. Estimation of the antioxidative and antitumor properties of broccoli cultivated in different in vitro conditions. In vitro germinated and cultivated broccoli seedlings, as well as spontaneously developed calli, were subjected to Soxhlet extraction. Antioxidative activity of the herbal extracts was determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH(•)) radical method. Antitumor properties of the extracts were determined using crown-gall tumor inhibition (potato disc) assay. Three, 10, 20, and 30 days old broccoli seedlings, cultivated in vitro on three different Murashige-Skoog media, two types of callus, and seedlings from sterile filter paper were used for extraction. In total, 15 aqueous extracts were tested for antioxidative and antitumor potential. Three day-old seedlings showed the highest antioxidative activity. Eleven out of 15 aqueous extracts demonstrated above 50% of crown-gall tumor inhibition in comparison with the control. Tumor inhibition was in association with types and concentrations of phytohormones presented in growing media. It is demonstrated that phytohormones in plant-growing media could affect the bioactive properties of broccoli either through increasing or decreasing their antioxidative and antitumor potential.

One new kind of phytohormonal signaling integrator: Up-and-coming GASA family genes.

PubMed

Zhang, Shengchun; Wang, Xiaojing

2017-02-01

GASA proteins are characterized by an N-terminal signal peptide and a C-terminal conserved GASA domain with 12 invariant cysteine residues. Despite being widely distributed among plant species, their functions are not completely elucidated and little is known about their mechanism of action. This review focuses on the current knowledge about the molecular structure, protein subcellular localization and phytohormones responses of this up-and-coming family of peptides. Furthermore, we discussed the roles of GASA proteins in plant growth and development, plant responses to biotic or abiotic stresses and their participation in phytohormonal signaling integration.

Exogenous abscisic acid significantly affects proteome in tea plant (Camellia sinensis) exposed to drought stress

USDA-ARS?s Scientific Manuscript database

Tea [Camellia sinensis (L.) O. Kuntze] is an important economic crop, and drought is the most important abiotic stress affecting yield and quality. Abscisic acid (ABA) is an important phytohormone responsible for activating drought resistance. Increased understanding of ABA effects on tea plant unde...

Herbivory-induced changes in the small-RNA transcriptome and phytohormone signaling in Nicotiana attenuata

PubMed Central

Pandey, Shree P.; Shahi, Priyanka; Gase, Klaus; Baldwin, Ian T.

2008-01-01

Phytohormones mediate the perception of insect-specific signals and the elicitation of defenses during insect attack. Large-scale changes in a plant's transcriptome ensue, but how these changes are regulated remains unknown. Silencing of RNA-directed RNA polymerase 1 (RdR1) makes Nicotiana attenuata highly susceptible to insect herbivores, suggesting that defense elicitation is under the direct control of small-RNAs (smRNAs). Using 454-sequencing, we characterized N. attenuata's smRNA transcriptome before and after insect-specific elicitation in wild-type (WT) and RdR1-silenced (irRdR1) plants. We predicted the targets of N. attenuata smRNAs in the genes related to phytohormone signaling (jasmonic acid, JA-Ile, and ethylene) known to mediate resistance responses, and we measured the elicited dynamics of phytohormone biosynthetic transcripts and phytohormone levels in time-course experiments with field- and glasshouse-grown plants. RdR1 silencing severely altered the induced transcript accumulation of 8 of the 10 genes, reduced JA, and enhanced ethylene levels after elicitation. Adding JA completely restored the insect resistance of irRdR1 plants. irRdR1 plants had photosynthetic rates, growth, and reproductive output indistinguishable from that of WT plants, suggesting unaltered primary metabolism. We conclude that the susceptibility of irRdR1 plants to herbivores is due to altered phytohormone signaling and that smRNAs play a central role in coordinating the large-scale transcriptional changes that occur after herbivore attack. Given the diversity of smRNAs that are elicited after insect attack and the recent demonstration of the ability of ingested smRNAs to silence transcript accumulation in lepidopteran larvae midguts, the smRNA responses of plants may also function as direct defenses. PMID:18339806

The roles of auxin in seed dormancy and germination.

PubMed

Shuai, Hai-wei; Meng, Yong-jie; Luo, Xiao-feng; Chen, Feng; Qi, Ying; Yang, Wen-yu; Shu, Kai

2016-04-01

Seed dormancy and germination are attractive topics in the fields of plant molecular biology as they are key stages during plant growth and development. Seed dormancy is intricately regulated by complex networks of phytohormones and numerous key genes, combined with diverse environmental cues. The transition from dormancy to germination is a very important biological process, and extensive studies have demonstrated that phytohormones abscisic acid (ABA) and gibberellin acid (GA) are major determinants. Consequently, the precise balance between ABA and GA can ensure that the seeds remain dormant under stress conditions and germinate at optimal times. Here we review the role of auxin in seed dormancy and germination. Auxin is one of the classic phytohormones effective during tropism growth and tissue differentiation. Recent studies, however, show that auxin possesses positive effects on seed dormancy, which suggests that auxin is the second phytohormone that induces seed dormancy, besides ABA. We will focus on the synthetic effects in detail between auxin and ABA pathways on seed dormancy and propose future research directions.

Fungal Production and Manipulation of Plant Hormones.

PubMed

Fonseca, Sandra; Radhakrishnan, Dhanya; Prasad, Kalika; Chini, Andrea

2018-01-01

Living organisms are part of a highly interconnected web of interactions, characterised by species nurturing, competing, parasitizing and preying on one another. Plants have evolved cooperative as well as defensive strategies to interact with neighbour organisms. Among these, the plant-fungus associations are very diverse, ranging from pathogenic to mutualistic. Our current knowledge of plant-fungus interactions suggests a sophisticated coevolution to ensure dynamic plant responses to evolving fungal mutualistic/pathogenic strategies. The plant-fungus communication relies on a rich chemical language. To manipulate the plant defence mechanisms, fungi produce and secrete several classes of biomolecules, whose modeof- action is largely unknown. Upon perception of the fungi, plants produce phytohormones and a battery of secondary metabolites that serve as defence mechanism against invaders or to promote mutualistic associations. These mutualistic chemical signals can be co-opted by pathogenic fungi for their own benefit. Among the plant molecules regulating plant-fungus interaction, phytohormones play a critical role since they modulate various aspects of plant development, defences and stress responses. Intriguingly, fungi can also produce phytohormones, although the actual role of fungalproduced phytohormones in plant-fungus interactions is poorly understood. Here, we discuss the recent advances in fungal production of phytohormone, their putative role as endogenous fungal signals and how fungi manipulate plant hormone balance to their benefits. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Sexual dimorphic floral development in dioecious plants revealed by transcriptome, phytohormone, and DNA methylation analysis in Populus tomentosa.

PubMed

Song, Yuepeng; Ma, Kaifeng; Ci, Dong; Chen, Qingqing; Tian, Jiaxing; Zhang, Deqiang

2013-12-01

Dioecious plants have evolved sex-specific floral development mechanisms. However, the precise gene expression patterns in dioecious plant flower development remain unclear. Here, we used andromonoecious poplar, an exceptional model system, to eliminate the confounding effects of genetic background of dioecious plants. Comparative transcriptome and physiological analysis allowed us to characterize sex-specific development of female and male flowers. Transcriptome analysis identified genes significantly differentially expressed between the sexes, including genes related to floral development, phytohormone synthesis and metabolism, and DNA methylation. Correlation analysis revealed a significant correlation between phytohormone signaling and gene expression, identifying specific phytohormone-responsive genes and their cis-regulatory elements. Two genes related to DNA methylation, METHYLTRANSFERASE1 (MET1) and DECREASED DNA METHYLATION 1 (DDM1), which are located in the sex determination region of Chromosome XIX, have differential expression between female and male flowers. A time-course analysis revealed that MET1 and DDM1 expression may produce different DNA methylation levels in female and male flowers. Understanding the interactions of phytohormone signaling, DNA methylation and target gene expression should lead to a better understanding of sexual differences in floral development. Thus, this study identifies a set of candidate genes for further studies of poplar sexual dimorphism and relates sex-specific floral development to physiological and epigenetic changes.

Silicon and water-deficit stress differentially modulate physiology and ultrastructure in wheat (Triticum aestivum L.).

PubMed

Xu, Ling; Islam, Faisal; Ali, Basharat; Pei, Zengfei; Li, Juanjuan; Ghani, Muhammad Awais; Zhou, Weijun

2017-08-01

Plants combat drought stress by coordinating various metabolic enzymes, and endogenous phytohormones, such as indole acetic acid (IAA) and abscisic acid (ABA). In the present study, 37-day-old wheat seedlings were subjected to the Hoagland solution with 20% PEG for 7 days (to create the artificial osmotic stress environment) in the greenhouse, and were supplemented with an optimized concentration (1.0 mM) of silicon (Si) to alleviate the negative effects of former stress on physiological, biochemical and phytohormones contents. Exogenous Si significantly improved plant growth parameters under osmotic stress compared to PEG treatment alone (the increase was up to 6 and 9% for shoot and root fresh weight, 4 and 12% for shoot and root dry weight, respectively). Moreover, Si significantly decreased the H 2 O 2 , MDA contents, electrolyte leakage, antioxidant enzyme activity (POD), and mineral contents (K and Ca) under osmotic stress but markedly increased the ascorbic acid(AsA), soluble sugar and mineral (Mg and Si) contents. Interestingly, Si application under water-deficit stress differently modulated the endogenous levels of ABA, IAA and JA in wheat plants compared to PEG treatment alone. This study suggests that exogenous Si improves the plant growth by modulating the nutrient (Na, Mg and Si) uptake and phytohormone levels in wheat under water-deficit stress.

S-nitrosylation mediates nitric oxide -auxin crosstalk in auxin signaling and polar auxin transport

USDA-ARS?s Scientific Manuscript database

Nitric oxide (NO) and auxin phytohormone cross talk has been implicated in plant development and growth. Addition and removal of NO moieties to cysteine residues of proteins, is termed S-nitrosylation and de-nitrosylation, respectively and functions as an on/off switch of protein activity. This dyna...

Arabidopsis thaliana GH3.15 acyl acid amido synthetase has a highly specific substrate preference for the auxin precursor indole-3-butyric acid.

PubMed

Sherp, Ashley M; Westfall, Corey S; Alvarez, Sophie; Jez, Joseph M

2018-03-23

Various phytohormones control plant growth and development and mediate biotic and abiotic stress responses. Gretchen Hagen 3 (GH3) acyl acid amido synthetases are plant enzymes that typically conjugate amino acids to indole-3-acetic acid (IAA) or jasmonic acid (JA) to inactivate or activate these phytohormones, respectively; however, the physiological and biological roles of many of these enzymes remain unclear. Using a biochemical approach, we found that the Arabidopsis thaliana GH3.15 (AtGH3.15) preferentially uses indole-3-butyric acid (IBA) and glutamine as substrates. The X-ray crystal structure of the AtGH3.15·AMP complex, modeling of IBA in the active site, and biochemical analysis of site-directed mutants provide insight on active site features that lead to AtGH3.15's preference for IBA. Assay-based in planta analysis of AtGH3.15-overexpressing lines indicated that their root elongation and lateral root density were resistant to IBA treatment but not to treatment with either IAA or JA. These findings suggest that AtGH3.15 may play a role in auxin homeostasis by modulating the levels of IBA for peroxisomal conversion to IAA. Analysis of AtGH3.15 promoter-driven yellow fluorescent protein reporter lines revealed that AtGH3.15 is expressed at significant levels in seedlings, roots, and parts of the siliques. We conclude that AtGH3.15 is unique in the GH3 protein family for its role in modifying IBA in auxin homeostasis and that it is the first GH3 protein shown to primarily modify a plant growth regulator other than IAA and JA. © 2018 Sherp et al.

Regulatory Peptides in Plants.

PubMed

Vanyushin, B F; Ashapkin, V V; Aleksandrushkina, N I

2017-02-01

Many different peptides regulating cell differentiation, growth, and development are found in plants. Peptides participate in regulation of plant ontogenesis starting from pollination, pollen tube growth, and the very early stages of embryogenesis, including formation of embryo and endosperm. They direct differentiation of meristematic stem cells, formation of tissues and individual organs, take part in regulation of aging, fruit maturation, and abscission of plant parts associated with apoptosis. Biological activity of peptides is observed at very low concentrations, and it has mainly signal nature and hormonal character. "Mature" peptides appear mainly due to processing of protein precursors with (or without) additional enzymatic modifications. Plant peptides differ in origin, structure, and functional properties. Their specific action is due to binding with respective receptors and interactions with various proteins and other factors. Peptides can also regulate physiological functions by direct peptide-protein interactions. Peptide action is coordinated with the action of known phytohormones (auxins, cytokinins, and others); thus, peptides control phytohormonal signal pathways.

The Role and Regulation of ABI5 (ABA-Insensitive 5) in Plant Development, Abiotic Stress Responses and Phytohormone Crosstalk

PubMed Central

Skubacz, Anna; Daszkowska-Golec, Agata; Szarejko, Iwona

2016-01-01

ABA Insensitive 5 (ABI5) is a basic leucine zipper transcription factor that plays a key role in the regulation of seed germination and early seedling growth in the presence of ABA and abiotic stresses. ABI5 functions in the core ABA signaling, which is composed of PYR/PYL/RCAR receptors, PP2C phosphatases and SnRK2 kinases, through the regulation of the expression of genes that contain the ABSCISIC ACID RESPONSE ELEMENT (ABRE) motif within their promoter region. The regulated targets include stress adaptation genes, e.g., LEA proteins. However, the expression and activation of ABI5 is not only dependent on the core ABA signaling. Many transcription factors such as ABI3, ABI4, MYB7 and WRKYs play either a positive or a negative role in the regulation of ABI5 expression. Additionally, the stability and activity of ABI5 are also regulated by other proteins through post-translational modifications such as phosphorylation, ubiquitination, sumoylation and S-nitrosylation. Moreover, ABI5 also acts as an ABA and other phytohormone signaling integrator. Components of auxin, cytokinin, gibberellic acid, jasmonate and brassinosteroid signaling and metabolism pathways were shown to take part in ABI5 regulation and/or to be regulated by ABI5. Monocot orthologs of AtABI5 have been identified. Although their roles in the molecular and physiological adaptations during abiotic stress have been elucidated, knowledge about their detailed action still remains elusive. Here, we describe the recent advances in understanding the action of ABI5 in early developmental processes and the adaptation of plants to unfavorable environmental conditions. We also focus on ABI5 relation to other phytohormones in the abiotic stress response of plants. PMID:28018412

Mitigation of NaCl Stress by Arbuscular Mycorrhizal Fungi through the Modulation of Osmolytes, Antioxidants and Secondary Metabolites in Mustard (Brassica juncea L.) Plants

PubMed Central

Sarwat, Maryam; Hashem, Abeer; Ahanger, Mohammad A.; Abd_Allah, Elsayed F.; Alqarawi, A. A.; Alyemeni, Mohammed N.; Ahmad, Parvaiz; Gucel, Salih

2016-01-01

Present work was carried out to investigate the possible role of arbuscular mycorrhizal fungi (AMF) in mitigating salinity-induced alterations in Brassica juncea L. Exposure to NaCl stress altered the morphological, physio-biochemical attributes, antioxidant activity, secondary metabolites and phytohormones in the mustard seedlings. The growth and biomass yield, leaf water content, and total chlorophyll content were decreased with NaCl stress. However, AMF-inoculated plants exhibited enhanced shoot and root length, elevated relative water content, enhanced chlorophyll content, and ultimately biomass yield. Lipid peroxidation and proline content were increased by 54.53 and 63.47%, respectively with 200 mM NaCl concentration. Further increase in proline content and decrease in lipid peroxidation was observed in NaCl-treated plants inoculated with AMF. The antioxidants, superoxide dismutase, ascorbate peroxidase, glutathione reductase, and reduced glutathione were increased by 48.35, 54.86, 43.85, and 44.44%, respectively, with 200 mM NaCl concentration. Further increase in these antioxidants has been observed in AMF-colonized plants indicating the alleviating role of AMF to salinity stress through antioxidant modulation. The total phenol, flavonoids, and phytohormones increase with NaCl treatment. However, NaCl-treated plants colonized with AMF showed further increase in the above parameters except ABA, which was reduced with NaCl+AMF treatment over the plants treated with NaCl alone. Our results demonstrated that NaCl caused negative effect on B. juncea seedlings; however, colonization with AMF enhances the NaCl tolerance by reforming the physio-biochemical attributes, activities of antioxidant enzymes, and production of secondary metabolites and phytohormones. PMID:27458462

Gibberellin in plant height control: old player, new story.

PubMed

Wang, Yijun; Zhao, Jia; Lu, Wenjie; Deng, Dexiang

2017-03-01

Height relates to plant architecture, lodging resistance, and yield performance. Growth-promoting phytohormones gibberellins (GAs) play a pivotal role in plant height control. Mutations in GA biosynthesis, metabolism, and signaling cascades influence plant height. Moreover, GA interacts with other phytohormones in the modulation of plant height. Here, we first briefly describe the regulation of plant height by altered GA pathway. Then, we depict effects of the crosstalk between GA and other phytohormones on plant height. We also dissect the co-localization of GA pathway genes and established quantitative genetic loci for plant height. Finally, we suggest ways forward for the application of hormone GA knowledge in breeding of crops with plant height ideotypes.

Phytohormone ecology : Herbivory byThrips tabaci induces greater ethylene production in intact onions than mechanical damage alone.

PubMed

Kendall, D M; Bjostad, L B

1990-03-01

Herbivory byThrips tabaci affected production of the phytohormone ethylene from living onion foliage. Ethylene analysis was performed by gas chromatography on intact onion tissue. Thrips feeding damage and a crushed thrips extract stimulated significantly greater production of eihylene than could be explained by either one-time or semicontinuous mechanical damage alone, suggesting that ethylene-inducing cues may be transferred to the plant during feeding. This is the first demonstration of increased ethylene production from insect-infested intact plants. This study suggests that herbivores affect both the phytohormone physiology and secondary chemistry of living plants because ethylene has been shown to enhance production of defensive phytochemicals.

Comparative analysis of root transcriptome profiles between drought-tolerant and susceptible wheat genotypes in response to water stress.

PubMed

Hu, Ling; Xie, Yan; Fan, Shoujin; Wang, Zongshuai; Wang, Fahong; Zhang, Bin; Li, Haosheng; Song, Jie; Kong, Lingan

2018-07-01

Water deficit is one of the major factors limiting crop productivity worldwide. Plant roots play a key role in uptaking water, perceiving and transducing of water deficit signals to shoot. Although the mechanisms of drought-tolerance have been reported recently, the transcriptional regulatory network of wheat root response to water stress has not been fully understood. In this study, drought-tolerant cultivar JM-262 and susceptible cultivar LM-2 are planted to characterize the root transcriptional changes and physiological responses to water deficit. A total of 8197 drought tolerance-associated differentially expressed genes (DEGs) are identified, these genes are mainly mapped to carbon metabolism, flavonoid biosynthesis, and phytohormone signal transduction. The number and expression level of DEGs involved in antioxidative and antiosmotic stresses are more enhanced in JM-262 under water stress. Furthermore, we find the DEGs related to root development are much more induced in JM-262 in phytohormone signal transduction and carbon metabolism pathway. In conclusion, JM-262 may alleviate the damage of drought by producing more osmoprotectants, ROS scavengers, biomass and energy. Interestingly, hormone signaling and cross-talk probably play an important role in promoting JM-262 greater root systems to take up more water, higher capabilities to induce more drought-related DEGs and higher resisitance to oxidative stresse. Copyright © 2018 Elsevier B.V. All rights reserved.

Pollination

PubMed Central

Kühn, Nathalie; Arce-Johnson, Patricio

2012-01-01

Berry formation is the process of ovary conversion into a functional fruit, and is characterized by abrupt changes in the content of several phytohormones, associated with pollination and fertilization. Much effort has been made in order to improve our understanding of berry development, particularly from veraison to post-harvest time. However, the period of berry formation has been poorly investigated, despite its importance. Phytohormones are involved in the control of fruit formation; hence it is important to understand the regulation of their content at this stage. Grapevine is an excellent fleshy-fruit plant model since its fruits have particularities that differentiate them from those of commonly studied organisms. For instance, berries are prepared to cope with stress by producing several antioxidants and they are non-climacteric fruits. Also its genome is fully sequenced, which allows to identify genes involved in developmental processes. In grapevine, no link has been established between pollination and phytohormone biosynthesis, until recently. Here we highlight relevant findings regarding pollination effect on gene expression related to phytohormone biosynthesis, and present results showing how quickly this effect is achieved. PMID:22301957

Genome-wide Analysis of Phosphoenolpyruvate Carboxylase Gene Family and Their Response to Abiotic Stresses in Soybean

PubMed Central

Wang, Ning; Zhong, Xiujuan; Cong, Yahui; Wang, Tingting; Yang, Songnan; Li, Yan; Gai, Junyi

2016-01-01

Phosphoenolpyruvate carboxylase (PEPC) plays an important role in assimilating atmospheric CO2 during C4 and crassulacean acid metabolism photosynthesis, and also participates in various non-photosynthetic processes, including fruit ripening, stomatal opening, supporting carbon–nitrogen interactions, seed formation and germination, and regulation of plant tolerance to stresses. However, a comprehensive analysis of PEPC family in Glycine max has not been reported. Here, a total of ten PEPC genes were identified in soybean and denominated as GmPEPC1-GmPEPC10. Based on the phylogenetic analysis of the PEPC proteins from 13 higher plant species including soybean, PEPC family could be classified into two subfamilies, which was further supported by analyses of their conserved motifs and gene structures. Nineteen cis-regulatory elements related to phytohormones, abiotic and biotic stresses were identified in the promoter regions of GmPEPC genes, indicating their roles in soybean development and stress responses. GmPEPC genes were expressed in various soybean tissues and most of them responded to the exogenously applied phytohormones. GmPEPC6, GmPEPC8 and GmPEPC9 were significantly induced by aluminum toxicity, cold, osmotic and salt stresses. In addition, the enzyme activities of soybean PEPCs were also up-regulated by these treatments, suggesting their potential roles in soybean response to abiotic stresses. PMID:27924923

Cytokinin Metabolism of Pathogenic Fungus Leptosphaeria maculans Involves Isopentenyltransferase, Adenosine Kinase and Cytokinin Oxidase/Dehydrogenase

PubMed Central

Trdá, Lucie; Barešová, Monika; Šašek, Vladimír; Nováková, Miroslava; Zahajská, Lenka; Dobrev, Petre I.; Motyka, Václav; Burketová, Lenka

2017-01-01

Among phytohormones, cytokinins (CKs) play an important role in controlling crucial aspects of plant development. Not only plants but also diverse microorganisms are able to produce phytohormones, including CKs, though knowledge concerning their biosynthesis and metabolism is still limited. In this work we demonstrate that the fungus Leptosphaeria maculans, a hemi-biotrophic pathogen of oilseed rape (Brassica napus), causing one of the most damaging diseases of this crop, is able to modify the CK profile in infected B. napus tissues, as well as produce a wide range of CKs in vitro, with the cis-zeatin derivatives predominating. The endogenous CK spectrum of L. maculans in vitro consists mainly of free CK bases, as opposed to plants, where other CK forms are mostly more abundant. Using functional genomics, enzymatic and feeding assays with CK bases supplied to culture media, we show that L. maculans contains a functional: (i) isopentenyltransferase (IPT) involved in cZ production; (ii) adenosine kinase (AK) involved in phosphorylation of CK ribosides to nucleotides; and (iii) CK-degradation enzyme cytokinin oxidase/dehydrogenase (CKX). Our data further indicate the presence of cis–trans isomerase, zeatin O-glucosyltransferase(s) and N6-(Δ2-isopentenyl)adenine hydroxylating enzyme. Besides, we report on a crucial role of LmAK for L. maculans fitness and virulence. Altogether, in this study we characterize in detail the CK metabolism of the filamentous fungi L. maculans and report its two novel components, the CKX and CK-related AK activities, according to our knowledge for the first time in the fungal kingdom. Based on these findings, we propose a model illustrating CK metabolism pathways in L. maculans. PMID:28785249

Microarray Analyses and Comparisons of Upper or Lower Flanks of Rice Shoot Base Preceding Gravitropic Bending

PubMed Central

Zang, Aiping; Chen, Haiying; Dou, Xianying; Jin, Jing; Cai, Weiming

2013-01-01

Gravitropism is a complex process involving a series of physiological pathways. Despite ongoing research, gravitropism sensing and response mechanisms are not well understood. To identify the key transcripts and corresponding pathways in gravitropism, a whole-genome microarray approach was used to analyze transcript abundance in the shoot base of rice (Oryza sativa sp. japonica) at 0.5 h and 6 h after gravistimulation by horizontal reorientation. Between upper and lower flanks of the shoot base, 167 transcripts at 0.5 h and 1202 transcripts at 6 h were discovered to be significantly different in abundance by 2-fold. Among these transcripts, 48 were found to be changed both at 0.5 h and 6 h, while 119 transcripts were only changed at 0.5 h and 1154 transcripts were changed at 6 h in association with gravitropism. MapMan and PageMan analyses were used to identify transcripts significantly changed in abundance. The asymmetric regulation of transcripts related to phytohormones, signaling, RNA transcription, metabolism and cell wall-related categories between upper and lower flanks were demonstrated. Potential roles of the identified transcripts in gravitropism are discussed. Our results suggest that the induction of asymmetrical transcription, likely as a consequence of gravitropic reorientation, precedes gravitropic bending in the rice shoot base. PMID:24040303

Parasitism by Cuscuta pentagona sequentially induces JA and SA defence pathways in tomato

Treesearch

Justin B. Runyon; Mark C. Mescher; Gary W. Felton; Consuelo M. De Moraes

2010-01-01

While plant responses to herbivores and pathogens are well characterized, responses to attack by other plants remain largely unexplored. We measured phytohormones and C18 fatty acids in tomato attacked by the parasitic plant Cuscuta pentagona, and used transgenic and mutant plants to explore the roles of the defence-related phytohormones salicylic...

Redox Regulation of Plant Development

PubMed Central

Considine, Michael J.

2014-01-01

Abstract Significance: We provide a conceptual framework for the interactions between the cellular redox signaling hub and the phytohormone signaling network that controls plant growth and development to maximize plant productivity under stress-free situations, while limiting growth and altering development on exposure to stress. Recent Advances: Enhanced cellular oxidation plays a key role in the regulation of plant growth and stress responses. Oxidative signals or cycles of oxidation and reduction are crucial for the alleviation of dormancy and quiescence, activating the cell cycle and triggering genetic and epigenetic control that underpin growth and differentiation responses to changing environmental conditions. Critical Issues: The redox signaling hub interfaces directly with the phytohormone network in the synergistic control of growth and its modulation in response to environmental stress, but a few components have been identified. Accumulating evidence points to a complex interplay of phytohormone and redox controls that operate at multiple levels. For simplicity, we focus here on redox-dependent processes that control root growth and development and bud burst. Future Directions: The multiple roles of reactive oxygen species in the control of plant growth and development have been identified, but increasing emphasis should now be placed on the functions of redox-regulated proteins, along with the central roles of reductants such as NAD(P)H, thioredoxins, glutathione, glutaredoxins, peroxiredoxins, ascorbate, and reduced ferredoxin in the regulation of the genetic and epigenetic factors that modulate the growth and vigor of crop plants, particularly within an agricultural context. Antioxid. Redox Signal. 21, 1305–1326. PMID:24180689

Root colonization and phytostimulation by phytohormones producing entophytic Nostoc sp. AH-12.

PubMed

Hussain, Anwar; Hamayun, Muhammad; Shah, Syed Tariq

2013-11-01

Nostoc, a nitrogen-fixing cyanobacterium, has great potential to make symbiotic associations with a wide range of plants and benefit its hosts with nitrogen in the form of nitrates. It may also use phytohormones as a tool to promote plant growth. Phytohormones [cytokinin (Ck) and IAA] were determined in the culture of an endophytic Nostoc isolated from rice roots. The strain was able to accumulate as well as release phytohormones to the culture media. Optimum growth conditions for the production of zeatin and IAA were a temperature of 25 °C and a pH of 8.0. Time-dependent increase in the accumulation and release of phytohormones was recorded. To evaluate the impact of cytokinins, an ipt knockout mutant in the background of Nostoc was generated by homologous recombination method. A sharp decline (up to 80 %) in the zeatin content was observed in the culture of mutant strain Nostoc AHM-12. Association of the mutant and wild type strain with rice and wheat roots was studied under axenic conditions. The efficacy of Nostoc to colonize plant root was significantly reduced (P < 0.05) as a result of ipt inactivation as evident by low chlorophyll a concentration in the roots. In contrast to the mutant strain, wild type strain showed good association with the roots and enhanced several growth parameters, such as fresh weight, dry weight, shoot length, and root length of the crop plants. The study clearly demonstrated that Ck is a tool of endophytic Nostoc to colonize plant root and promote its growth.

Nitric oxide and phytohormone interactions: current status and perspectives

PubMed Central

Freschi, Luciano

2013-01-01

Nitric oxide (NO) is currently considered a ubiquitous signal in plant systems, playing significant roles in a wide range of responses to environmental and endogenous cues. During the signaling events leading to these plant responses, NO frequently interacts with plant hormones and other endogenous molecules, at times originating remarkably complex signaling cascades. Accumulating evidence indicates that virtually all major classes of plant hormones may influence, at least to some degree, the endogenous levels of NO. In addition, studies conducted during the induction of diverse plant responses have demonstrated that NO may also affect biosynthesis, catabolism/conjugation, transport, perception, and/or transduction of different phytohormones, such as auxins, gibberellins, cytokinins, abscisic acid, ethylene, salicylic acid, jasmonates, and brassinosteroids. Although still not completely elucidated, the mechanisms underlying the interaction between NO and plant hormones have recently been investigated in a number of species and plant responses. This review specifically focuses on the current knowledge of the mechanisms implicated in NO–phytohormone interactions during the regulation of developmental and metabolic plant events. The modifications triggered by NO on the transcription of genes encoding biosynthetic/degradative enzymes as well as proteins involved in the transport and signal transduction of distinct plant hormones will be contextualized during the control of developmental, metabolic, and defense responses in plants. Moreover, the direct post-translational modification of phytohormone biosynthetic enzymes and receptors through S-nitrosylation will also be discussed as a key mechanism for regulating plant physiological responses. Finally, some future perspectives toward a more complete understanding of NO–phytohormone interactions will also be presented and discussed. PMID:24130567

Auxin synthesis gene tms1 driven by tuber-specific promoter alters hormonal status of transgenic potato plants and their responses to exogenous phytohormones.

PubMed

Kolachevskaya, Oksana O; Sergeeva, Lidiya I; Floková, Kristyna; Getman, Irina A; Lomin, Sergey N; Alekseeva, Valeriya V; Rukavtsova, Elena B; Buryanov, Yaroslav I; Romanov, Georgy A

2017-03-01

Ectopic auxin overproduction in transgenic potato leads to enhanced productivity accompanied with concerted and occasional changes in hormonal status, and causing altered response of transformants to exogenous auxin or cytokinin. Previously, we generated potato transformants expressing Agrobacterium-derived auxin synthesis gene tms1 driven by tuber-specific patatin gene promoter (B33-promoter). Here, we studied the endogenous hormonal status and the response to exogenous phytohormones in tms1 transformants cultured in vitro. Adding indole-3-acetic acid (IAA) or kinetin to culture medium affected differently tuberization of tms1-transformed and control plants, depending also on sucrose content in the medium. Exogenous phytohormones ceased to stimulate the tuber initiation in transformants at high (5-8%) sucrose concentration, while in control plants the stimulation was observed in all experimental settings. Furthermore, exogenous auxin partly inhibited the tuber initiation, and exogenous cytokinin reduced the average tuber weight in most transformants at high sucrose content. The elevated auxin level in tubers of the transformants was accompanied with a decrease in content of cytokinin bases and their ribosides in tubers and most shoots. No concerted changes in contents of abscisic, jasmonic, salicylic acids and gibberellins in tubers were detected. The data on hormonal status indicated that the enhanced productivity of tms1 transformants was due to auxin and not mediated by other phytohormones. In addition, exogenous cytokinin was shown to upregulate the expression of genes encoding orthologs of auxin receptors. Overall, the results showed that tms1 expression and local increase in IAA level in transformants affect both the balance of endogenous cytokinins and the dynamics of tuberization in response to exogenous hormones (auxin, cytokinin), the latter reaction depending also on the carbohydrate supply. We introduce a basic model for the hormonal network controlling tuberization.

Development of a novel amide-silica stationary phase for the reversed-phase HPLC separation of different classes of phytohormones.

PubMed

Aral, Hayriye; Aral, Tarık; Ziyadanoğulları, Berrin; Ziyadanoğulları, Recep

2013-11-15

A novel amide-bonded silica stationary phase was prepared starting from N-Boc-phenylalanine, cyclohexylamine and spherical silica gel (4 µm, 60 Å). The amide ligand was synthesised with high yield. The resulting amide bonded stationary phase was characterised by SEM, IR and elemental analysis. The resulting selector bearing a polar amide group is used for the reversed-phase chromatography separation of different classes of thirteen phytohormones (plant hormones). The chromatographic behaviours of these analytes on the amide-silica stationary phase were compared with those of RP-C18 column under same conditions. The effects of different separation conditions, such as mobile phase, pH value, flow rate and temperature, on the separation and retention behaviours of the 13 phytohormones in this system were studied. The optimum separation was achieved using reversed-phase HPLC gradient elution with an aqueous mobile phase containing pH=6.85 potassium phosphate buffer (20 mM) and acetonitrile with a 22 °C column temperature. Under these experimental conditions, the 12 phytohormones could be separated and detected at 230 or 270 nm within 26 min. Copyright © 2013 Elsevier B.V. All rights reserved.

JPRS Report, Science & Technology, USSR: Life Sciences

DTIC Science & Technology

1987-11-05

Sciences, Moscow] [Abstract] Derivatives of pyroglutamic acid , without the histidyl-proline fragment and containing gamma-amino butyric acid [GABA] as...activity of phytohormones, enzymes, carbohydrate metabolism, structural and functional changes of membranes, their lipid and fatty acid composition...Glyugitsur showed the influence of the initial heterogeneity of the suspension on the dynamics of acid resistance of erythrocytes during storage of blood at

Presence of abscisic acid, a phytohormone, in the mammalian brain

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

Le Page-Degivry, M.T.; Bidard, J.N.; Rouvier, E.

1986-02-01

This paper reports the presence of abscisic acid, one of the most important phytohormones, in the central nervous system of pigs and rats. The identification of this hormone in brain was made after extensive purification by using a radioimmunoassay that is very specific for (+)-cis-abscisic acid. The final product of purification from mammalian brain has the same properties as authentic abscisic acid: it crossreacts in the radioimmunoassay for the phytohormone and it has the same retention properties and the same gas chromatography/mass spectrometry characteristics. Moreover, like (+)-cis-abscisic acid itself, the brain factor inhibits stomatal apertures of abaxial epidermis strips ofmore » Setcreasea purpurea Boom (Commelinaceae). The presence of abscisic acid conjugates that are present in plants has also been identified in brain.« less

A regulatory framework for shoot stem cell control integrating metabolic, transcriptional, and phytohormone signals.

PubMed

Schuster, Christoph; Gaillochet, Christophe; Medzihradszky, Anna; Busch, Wolfgang; Daum, Gabor; Krebs, Melanie; Kehle, Andreas; Lohmann, Jan U

2014-02-24

Plants continuously maintain pluripotent stem cells embedded in specialized tissues called meristems, which drive long-term growth and organogenesis. Stem cell fate in the shoot apical meristem (SAM) is controlled by the homeodomain transcription factor WUSCHEL (WUS) expressed in the niche adjacent to the stem cells. Here, we demonstrate that the bHLH transcription factor HECATE1 (HEC1) is a target of WUS and that it contributes to SAM function by promoting stem cell proliferation, while antagonizing niche cell activity. HEC1 represses the stem cell regulators WUS and CLAVATA3 (CLV3) and, like WUS, controls genes with functions in metabolism and hormone signaling. Among the targets shared by HEC1 and WUS are phytohormone response regulators, which we show to act as mobile signals in a universal feedback system. Thus, our work sheds light on the mechanisms guiding meristem function and suggests that the underlying regulatory system is far more complex than previously anticipated. Copyright © 2014 Elsevier Inc. All rights reserved.

Toward facilitating microalgae cope with effluent from anaerobic digestion of kitchen waste: the art of agricultural phytohormones.

PubMed

Pei, Haiyan; Jiang, Liqun; Hou, Qingjie; Yu, Ze

2017-01-01

Although numerous studies have used wastewater as substitutes to cultivate microalgae, most of them obtained weaker algal viability than standard media. Some studies demonstrated a promotion of phytohormones on algal growth in standard media. For exploiting a strategy to improve algal biomass accumulation in effluent from anaerobic digestion of kitchen waste (ADE-KW), the agricultural phytohormones gibberellin, indole-3-acetic acid, and brassinolide (GIB) were applied to Chlorella SDEC-11 and Scenedesmus SDEC-13 at different stages of algal growth. Previous studies have demonstrated a promotion of phytohormones on algal growth in standard media, but attempts have been scarce, focusing on wastewater cultivation system. In addition, the effects of wastewater on algal morphology and ultrastructure have not been revealed so far, much less on the mechanism of the role of phytohormones on algae. ADE-KW disrupted the membranes of nuclear and chloroplast in ultrastructural cell of SDEC-11, and reduced the room between chloroplast and cell membrane and increased the starch size of SDEC-13. This reduced algal growth and biocompound accumulation, but SDEC-13 had greater adaptation to ADE-KW than SDEC-11. Moreover, inoculation with an algal seed pretreated with GIB aided the adaptability and viability of algae in ADE-KW, which for SDEC-13 was even promoted to the level in BG11. GIB mitigated the inhibition of ADE-KW on algal cell division and photosynthetic pigments and apparatus, and increased lipid droplets, which might result from the change in the synthesis and the fate of nicotinamide adenine dinucleotide phosphate. GIB addition significantly promoted lipid productivity of the two algal species, following 13 mg L -1  d -1 of SDEC-11 in B + ADE-KW and especially 13 mg L -1  d -1 of SDEC-13 achieved during the priming of algal seed with the hormones, which is 139% higher than 5 mg L -1  d -1 achieved in ADE-KW control. Agricultural phytohormones could be applied as a strategy for promoting biomass and biocompound accumulation of algae in ADE-KW, in which pretreatment of the algal inoculum with hormones is a unique way to help algae survive under stress. Considering our results and treatment technology for kitchen waste, a more feasible and economic plant can be built incorporating anaerobic digestion, algae cultivation with ADE-KW assisted with phytohormones, and biodiesel production.

FRET-based reporters for the direct visualization of abscisic acid concentration changes and distribution in Arabidopsis

PubMed Central

Waadt, Rainer; Hitomi, Kenichi; Nishimura, Noriyuki; Hitomi, Chiharu; Adams, Stephen R; Getzoff, Elizabeth D; Schroeder, Julian I

2014-01-01

Abscisic acid (ABA) is a plant hormone that regulates plant growth and development and mediates abiotic stress responses. Direct cellular monitoring of dynamic ABA concentration changes in response to environmental cues is essential for understanding ABA action. We have developed ABAleons: ABA-specific optogenetic reporters that instantaneously convert the phytohormone-triggered interaction of ABA receptors with PP2C-type phosphatases to send a fluorescence resonance energy transfer (FRET) signal in response to ABA. We report the design, engineering and use of ABAleons with ABA affinities in the range of 100–600 nM to map ABA concentration changes in plant tissues with spatial and temporal resolution. High ABAleon expression can partially repress Arabidopsis ABA responses. ABAleons report ABA concentration differences in distinct cell types, ABA concentration increases in response to low humidity and NaCl in guard cells and to NaCl and osmotic stress in roots and ABA transport from the hypocotyl to the shoot and root. DOI: http://dx.doi.org/10.7554/eLife.01739.001 PMID:24737861

Nepenthesin protease activity indicates digestive fluid dynamics in carnivorous nepenthes plants.

PubMed

Buch, Franziska; Kaman, Wendy E; Bikker, Floris J; Yilamujiang, Ayufu; Mithöfer, Axel

2015-01-01

Carnivorous plants use different morphological features to attract, trap and digest prey, mainly insects. Plants from the genus Nepenthes possess specialized leaves called pitchers that function as pitfall-traps. These pitchers are filled with a digestive fluid that is generated by the plants themselves. In order to digest caught prey in their pitchers, Nepenthes plants produce various hydrolytic enzymes including aspartic proteases, nepenthesins (Nep). Knowledge about the generation and induction of these proteases is limited. Here, by employing a FRET (fluorescent resonance energy transfer)-based technique that uses a synthetic fluorescent substrate an easy and rapid detection of protease activities in the digestive fluids of various Nepenthes species was feasible. Biochemical studies and the heterologously expressed Nep II from Nepenthes mirabilis proved that the proteolytic activity relied on aspartic proteases, however an acid-mediated auto-activation mechanism was necessary. Employing the FRET-based approach, the induction and dynamics of nepenthesin in the digestive pitcher fluid of various Nepenthes plants could be studied directly with insect (Drosophila melanogaster) prey or plant material. Moreover, we observed that proteolytic activity was induced by the phytohormone jasmonic acid but not by salicylic acid suggesting that jasmonate-dependent signaling pathways are involved in plant carnivory.

Nepenthesin Protease Activity Indicates Digestive Fluid Dynamics in Carnivorous Nepenthes Plants

PubMed Central

Buch, Franziska; Kaman, Wendy E.; Bikker, Floris J.; Yilamujiang, Ayufu; Mithöfer, Axel

2015-01-01

Carnivorous plants use different morphological features to attract, trap and digest prey, mainly insects. Plants from the genus Nepenthes possess specialized leaves called pitchers that function as pitfall-traps. These pitchers are filled with a digestive fluid that is generated by the plants themselves. In order to digest caught prey in their pitchers, Nepenthes plants produce various hydrolytic enzymes including aspartic proteases, nepenthesins (Nep). Knowledge about the generation and induction of these proteases is limited. Here, by employing a FRET (fluorescent resonance energy transfer)-based technique that uses a synthetic fluorescent substrate an easy and rapid detection of protease activities in the digestive fluids of various Nepenthes species was feasible. Biochemical studies and the heterologously expressed Nep II from Nepenthes mirabilis proved that the proteolytic activity relied on aspartic proteases, however an acid-mediated auto-activation mechanism was necessary. Employing the FRET-based approach, the induction and dynamics of nepenthesin in the digestive pitcher fluid of various Nepenthes plants could be studied directly with insect (Drosophila melanogaster) prey or plant material. Moreover, we observed that proteolytic activity was induced by the phytohormone jasmonic acid but not by salicylic acid suggesting that jasmonate-dependent signaling pathways are involved in plant carnivory. PMID:25750992

Exogenous short-term silicon application regulates macro-nutrients, endogenous phytohormones, and protein expression in Oryza sativa L.

PubMed

Jang, Soo-Won; Kim, Yoonha; Khan, Abdul Latif; Na, Chae-In; Lee, In-Jung

2018-01-04

Silicon (Si) has been known to regulate plant growth; however, the underlying mechanisms of short-term exogenous Si application on the regulation of calcium (Ca) and nitrogen (N), endogenous phytohormones, and expression of essential proteins have been little understood. Exogenous Si application significantly increased Si content as compared to the control. Among Si treatments, 1.0 mM Si application showed increased phosphorus content as compared to other Si treatments (0.5, 2.0, and 4.0 mM). However, Ca accumulation was significantly reduced (1.8- to 2.0-fold) at the third-leaf stage in the control, whereas all Si treatments exhibited a dose-dependent increase in Ca as determined by radioisotope 45 Ca analysis. Similarly, the radioisotope 15 N for nitrogen localization and uptake showed a varying but reduced response (ranging from 1.03-10.8%) to different Si concentrations as compared to 15 N application alone. Physiologically active endogenous gibberellin (GA 1 ) was also significantly higher with exogenous Si (1.0 mM) as compared to GA 20 and the control plants. A similar response was noted for endogenous jasmonic and salicylic acid synthesis in rice plants with Si application. Proteomic analysis revealed the activation of several essential proteins, such as Fe-S precursor protein, putative thioredoxin, Ser/Thr phosphatase, glucose-6-phosphate isomerase (G6P), and importin alpha-1b (Imp3), with Si application. Among the most-expressed proteins, confirmatory gene expression analysis for G6P and Imp3 showed a similar response to those of the Si treatments. In conclusion, the current results suggest that short-term exogenous Si can significantly regulate rice plant physiology by influencing Ca, N, endogenous phytohormones, and proteins, and that 1.0 mM Si application is more beneficial to plants than higher concentrations.

Friends or foes: new insights in jasmonate and ethylene co-actions.

PubMed

Zhu, Ziqiang; Lee, Benjamin

2015-03-01

One strategy for sessile plants to adapt to their surrounding environment involves the modulation of their various internal phytohormone signaling and distributions when the plants sense environmental change. There are currently dozens of identified phytohormones in plant cells and they act in concert to regulate plant growth, development, metabolism and defense. It has been determined that phytohormones often act together to achieve certain physiological functions. Thus, the study of hormone-hormone interactions is becoming a competitive research field for deciphering the underlying regulatory mechanisms. Among phytohormones, jasmonate and ethylene present a fascinating case of synergism and antagonism. They are commonly recognized as defense hormones that act synergistically. Plants impaired in jasmonate and/or ethylene signaling are susceptible to infections by necrotrophic fungi, suggesting that these two hormones are both required for defense. Moreover, jasmonate and ethylene also act antagonistically, such as in the regulation of apical hook development and wounding responses. Here, we highlight the recent breakthroughs in the understanding of jasmonate-ethylene co-actions and point out the potential power of studying protein-protein interactions for systematically exploring signal cross-talk. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Overexpression of blueberry FLOWERING LOCUS T is associated with changes in the expression of phytohormone-related genes in blueberry plants.

PubMed

Gao, Xuan; Walworth, Aaron E; Mackie, Charity; Song, Guo-Qing

2016-01-01

Flowering locus T ( FT ) is a primary integrator in the regulation of plant flowering. Overexpressing a blueberry ( Vaccinium corymbosum L.) FT gene ( VcFT ) (herein VcFT -OX) resulted in early flowering and dwarfing in 'Aurora' plants (herein 'VcFT-Aurora'). In this study, we found that VcFT -OX reduced shoot regeneration from leaf explants. To investigate the potential roles of the phytohormone pathway genes associated with VcFT -OX, differentially expressed ( DE ) genes in leaf tissues of 'VcFT-Aurora' plants were annotated and analyzed using non-transgenic 'Aurora' plants as a control. Three DE floral genes, including the blueberry SUPPRESSOR of Overexpression of constans 1 ( VcSOC1 ) (gibberellin related), Abscisic acid responsive elements-binding factor 2 ( VcABF2 ) and protein related to ABI3/VP1 ( VcABI3/VP1 ) (ethylene-related), are present under both the phytohormone-responsive and the dwarfing-related Gene Ontology terms. The gene networks of the DE genes overall showed the molecular basis of the multifunctional aspects of VcFT overexpression beyond flowering promotion and suggested that phytohormone changes could be signaling molecules with important roles in the phenotypic changes driven by VcFT -OX.

Overexpression of blueberry FLOWERING LOCUS T is associated with changes in the expression of phytohormone-related genes in blueberry plants

PubMed Central

Gao, Xuan; Walworth, Aaron E; Mackie, Charity; Song, Guo-qing

2016-01-01

Flowering locus T (FT) is a primary integrator in the regulation of plant flowering. Overexpressing a blueberry (Vaccinium corymbosum L.) FT gene (VcFT) (herein VcFT-OX) resulted in early flowering and dwarfing in ‘Aurora’ plants (herein ‘VcFT-Aurora’). In this study, we found that VcFT-OX reduced shoot regeneration from leaf explants. To investigate the potential roles of the phytohormone pathway genes associated with VcFT-OX, differentially expressed (DE) genes in leaf tissues of ‘VcFT-Aurora’ plants were annotated and analyzed using non-transgenic ‘Aurora’ plants as a control. Three DE floral genes, including the blueberry SUPPRESSOR of Overexpression of constans 1 (VcSOC1) (gibberellin related), Abscisic acid responsive elements-binding factor 2 (VcABF2) and protein related to ABI3/VP1 (VcABI3/VP1) (ethylene-related), are present under both the phytohormone-responsive and the dwarfing-related Gene Ontology terms. The gene networks of the DE genes overall showed the molecular basis of the multifunctional aspects of VcFT overexpression beyond flowering promotion and suggested that phytohormone changes could be signaling molecules with important roles in the phenotypic changes driven by VcFT-OX. PMID:27818778

2, 3-Butanediol activated disease-resistance of creeping bentgrass by inducing phytohormone and antioxidant responses.

PubMed

Shi, Yi; Liu, Xinju; Fang, Yuanyuan; Tian, Qing; Jiang, Hanyu; Ma, Huiling

2018-06-12

Brown patch, caused by Rhizoctonia solani, is a serious disease in Agrostis stolonifera. 2, 3-butanediol (2, 3-BD) is the major component of volatile organic compounds and was found to initiate induced systemic resistance (ISR). To investigate the induced resistance mechanism of 2, 3-BD, we examined the effects of resistance by area affected, along with changes in the content of phytohormones (Zeatin (ZT), Abscisic Acid (ABA) and Indole-3-Acetic Acid (IAA)), the activities of three phenylpropanoid metabolic enzymes (Phenylalaninammo-Nialyase (PAL), Chalcone Isomerase (CHI) and 4-Coumarate:Coenzyme A Ligase (4CL)) and the level of secondary metabolites (total phenols, flavonoid and lignin). The result showed that 2, 3-BD treatment at 250 μmoL/L had the best induction effect with the area affected decreased from 95% of the control to 55%. Compared to the controls, treatment with 250 μmoL/L 2, 3-BD induced higher levels of PAL, CHI and 4CL activity and increased total phenols, flavonoid and lignin levels. While 2, 3-BD treatment decreased the content of ZT and ABA but increased the content of IAA compared to controls. This study provides a basis for elucidating the mechanism of 2, 3-BD as a new plant disease control agent. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

A molecular framework of light-controlled phytohormone action in Arabidopsis.

PubMed

Zhong, Shangwei; Shi, Hui; Xue, Chang; Wang, Lei; Xi, Yanpeng; Li, Jigang; Quail, Peter H; Deng, Xing Wang; Guo, Hongwei

2012-08-21

Environmental changes strongly affect plant growth and development. Phytohormones, endogenous plant-made small molecules such as ethylene, regulate a wide range of processes throughout the lifetime of plants. The ability of plants to integrate external signals with endogenous regulatory pathways is vital for their survival. Ethylene has been found to suppress hypocotyl elongation in darkness while promoting it in light. How ethylene regulates hypocotyl elongation in such opposite ways is largely unknown. In particular, how light modulates and even reverses the function of ethylene has yet to be characterized. Here we show that the basic-helix-loop-helix transcription factor phytochrome-interacting factor 3 (PIF3) is directly activated by ETHYLENE-INSENSITIVE 3 (EIN3) and is indispensible for ethylene-induced hypocotyl elongation in light. Ethylene via EIN3 concomitantly activates two contrasting pathways: the PIF3-dependent growth-promoting pathway and an ethylene response factor 1 (ERF1)-mediated growth-inhibiting pathway. In the light, growth-promoting PIFs are limiting due to light-dependent destabilization, and thus ethylene stimulates growth under these conditions. In contrast, ERF1 is destabilized, and thus limiting, under dark conditions, explaining why ethylene inhibits growth in the dark. Our findings provide a mechanistic insight into how light modulates internal hormone-regulated plant growth. Copyright © 2012 Elsevier Ltd. All rights reserved.

Identification and mechanism of ABA receptor antagonism

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

Melcher, Karsten; Xu, Yong; Ng, Ley-Moy

2010-11-11

The phytohormone abscisic acid (ABA) functions through a family of fourteen PYR/PYL receptors, which were identified by resistance to pyrabactin, a synthetic inhibitor of seed germination. ABA activates these receptors to inhibit type 2C protein phosphatases, such as ABI1, yet it remains unclear whether these receptors can be antagonized. Here we demonstrate that pyrabactin is an agonist of PYR1 and PYL1 but is unexpectedly an antagonist of PYL2. Crystal structures of the PYL2-pyrabactin and PYL1-pyrabactin-ABI1 complexes reveal the mechanism responsible for receptor-selective activation and inhibition, which enables us to design mutations that convert PYL1 to a pyrabactin-inhibited receptor and PYL2more » to a pyrabactin-activated receptor and to identify new pyrabactin-based ABA receptor agonists. Together, our results establish a new concept of ABA receptor antagonism, illustrate its underlying mechanisms and provide a rational framework for discovering novel ABA receptor ligands.« less

YODA MAP3K kinase regulates plant immune responses conferring broad-spectrum disease resistance.

PubMed

Sopeña-Torres, Sara; Jordá, Lucía; Sánchez-Rodríguez, Clara; Miedes, Eva; Escudero, Viviana; Swami, Sanjay; López, Gemma; Piślewska-Bednarek, Mariola; Lassowskat, Ines; Lee, Justin; Gu, Yangnan; Haigis, Sabine; Alexander, Danny; Pattathil, Sivakumar; Muñoz-Barrios, Antonio; Bednarek, Pawel; Somerville, Shauna; Schulze-Lefert, Paul; Hahn, Michael G; Scheel, Dierk; Molina, Antonio

2018-04-01

Mitogen-activated protein kinases (MAPKs) cascades play essential roles in plants by transducing developmental cues and environmental signals into cellular responses. Among the latter are microbe-associated molecular patterns perceived by pattern recognition receptors (PRRs), which trigger immunity. We found that YODA (YDA) - a MAPK kinase kinase regulating several Arabidopsis developmental processes, like stomatal patterning - also modulates immune responses. Resistance to pathogens is compromised in yda alleles, whereas plants expressing the constitutively active YDA (CA-YDA) protein show broad-spectrum resistance to fungi, bacteria, and oomycetes with different colonization modes. YDA functions in the same pathway as ERECTA (ER) Receptor-Like Kinase, regulating both immunity and stomatal patterning. ER-YDA-mediated immune responses act in parallel to canonical disease resistance pathways regulated by phytohormones and PRRs. CA-YDA plants exhibit altered cell-wall integrity and constitutively express defense-associated genes, including some encoding putative small secreted peptides and PRRs whose impairment resulted in enhanced susceptibility phenotypes. CA-YDA plants show strong reprogramming of their phosphoproteome, which contains protein targets distinct from described MAPKs substrates. Our results suggest that, in addition to stomata development, the ER-YDA pathway regulates an immune surveillance system conferring broad-spectrum disease resistance that is distinct from the canonical pathways mediated by described PRRs and defense hormones. © 2018 Universidad Politécnica de Madrid (UPM) New Phytologist © 2018 New Phytologist Trust.

Karrikins: Regulators Involved in Phytohormone Signaling Networks during Seed Germination and Seedling Development

PubMed Central

Meng, Yongjie; Shuai, Haiwei; Luo, Xiaofeng; Chen, Feng; Zhou, Wenguan; Yang, Wenyu; Shu, Kai

2017-01-01

Seed germination and early seedling establishment are critical stages during a plant’s life cycle. These stages are precisely regulated by multiple internal factors, including phytohormones and environmental cues such as light. As a family of small molecules discovered in wildfire smoke, karrikins (KARs) play a key role in various biological processes, including seed dormancy release, germination regulation, and seedling establishment. KARs show a high similarity with strigolactone (SL) in both chemical structure and signaling transduction pathways. Current evidence shows that KARs may regulate seed germination by mediating the biosynthesis and/or signaling transduction of abscisic acid (ABA), gibberellin (GA) and auxin [indoleacetic acid (IAA)]. Interestingly, KARs regulate seed germination differently in different species. Furthermore, the promotion effect on seedling establishment implies that KARs have a great potential application in alleviating shade avoidance response, which attracts more and more attention in plant molecular biology. In these processes, KARs may have complicated interactions with phytohormones, especially with IAA. In this updated review, we summarize the current understanding of the relationship between KARs and SL in the chemical structure, signaling pathway and the regulation of plant growth and development. Further, the crosstalk between KARs and phytohormones in regulating seed germination and seedling development and that between KARs and IAA during shade responses are discussed. Finally, future challenges and research directions for the KAR research field are suggested. PMID:28174573

Detection of biosynthetic gene and phytohormone production by endophytic actinobacteria associated with Solanum lycopersicum and their plant-growth-promoting effect.

PubMed

Passari, Ajit Kumar; Chandra, Preeti; Zothanpuia; Mishra, Vineet Kumar; Leo, Vincent Vineeth; Gupta, Vijai Kumar; Kumar, Brijesh; Singh, Bhim Pratap

2016-10-01

In the present study, fifteen endophytic actinobacterial isolates recovered from Solanum lycopersicum were studied for their antagonistic potential and plant-growth-promoting (PGP) traits. Among them, eight isolates showed significant antagonistic and PGP traits, identified by amplification of the 16S rRNA gene. Isolate number DBT204, identified as Streptomyces sp., showed multiple PGP traits tested in planta and improved a range of growth parameters in seedlings of chili (Capsicum annuum L.) and tomato (S. lycopersicum L.). Further, genes of indole acetic acid (iaaM) and 1-aminocyclopropane-1-carboxylate (ACC) deaminase (acdS) were successively amplified from five strains. Six antibiotics (trimethoprim, fluconazole, chloramphenicol, nalidixic acid, rifampicin and streptomycin) and two phytohormones [indole acetic acid (IAA) and kinetin (KI)] were detected and quantified in Streptomyces sp. strain DBT204 using UPLC-ESI-MS/MS. The study indicates the potential of these PGP strains for production of phytohormones and shows the presence of biosynthetic genes responsible for production of secondary metabolites. It is the first report showing production of phytohormones (IAA and KI) by endophytic actinobacteria having PGP and biosynthetic potential. We propose Streptomyces sp. strain DBT204 for inoculums production and development of biofertilizers for enhancing growth of chili and tomato seedlings. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Minimising toxicity of cadmium in plants--role of plant growth regulators.

PubMed

Asgher, Mohd; Khan, M Iqbal R; Anjum, Naser A; Khan, Nafees A

2015-03-01

A range of man-made activities promote the enrichment of world-wide agricultural soils with a myriad of chemical pollutants including cadmium (Cd). Owing to its significant toxic consequences in plants, Cd has been one of extensively studied metals. However, sustainable strategies for minimising Cd impacts in plants have been little explored. Plant growth regulators (PGRs) are known for their role in the regulation of numerous developmental processes. Among major PGRs, plant hormones (such as auxins, gibberellins, cytokinins, abscisic acid, jasmonic acid, ethylene and salicylic acid), nitric oxide (a gaseous signalling molecule), brassinosteroids (steroidal phytohormones) and polyamines (group of phytohormone-like aliphatic amine natural compounds with aliphatic nitrogen structure) have gained attention by agronomist and physiologist as a sustainable media to induce tolerance in abiotic-stressed plants. Considering recent literature, this paper: (a) overviews Cd status in soil and its toxicity in plants, (b) introduces major PGRs and overviews their signalling in Cd-exposed plants, (c) appraises mechanisms potentially involved in PGR-mediated enhanced plant tolerance to Cd and (d) highlights key aspects so far unexplored in the subject area.

Proteomic analysis of JAZ interacting proteins under methyl jasmonate treatment in finger millet.

PubMed

Sen, Saswati; Kundu, Sangeeta; Dutta, Samir Kr

2016-11-01

Jasmonic acid (JA) signaling pathway in plants is activated against various developmental processes as well as biotic and abiotic stresses. The Jasmonate ZIM-domain (JAZ) protein family, the key regulator of plant JA signaling pathway, also participates in phytohormone crosstalk. This is the first study revealing the in vivo interactions of finger millet (Eleusine coracana (L.) Gaertn.) JAZ protein (EcJAZ) under methyl jasmonate (MJ) treatment. The aim of the study was to explore not only the JA signaling pathway but also the phytohormone signaling crosstalk of finger millet, a highly important future crop. From the MJ-treated finger millet seedlings, the EcJAZ interacting proteins were purified by affinity chromatography with the EcJAZ-matrix. Twenty-one proteins of varying functionalities were successfully identified by MALDI-TOF-TOF Mass spectrometry. Apart from the previously identified JAZ binding proteins, most prominently, EcJAZ was found to interact with transcription factors like NAC, GATA and also with Cold responsive protein (COR), etc. that might have extended the range of functionalities of JAZ proteins. Moreover, to evaluate the interactions of EcJAZ in the JA-co-receptor complex, we generated ten in-silico models containing the EcJAZ degron and the COI1-SKP1 of five monocot cereals viz., rice, wheat, maize, Sorghum and Setaria with JA-Ile or coronatine. Our results indicated that the EcJAZ protein of finger millet could act as the signaling hub for the JA and other phytohormone signaling pathways, in response to a diverse set of stressors and developmental cues to provide survival fitness to the plant. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Self-assembly of gibberellic amide assemblies and their applications in the growth and fabrication of ordered gold nanoparticles

NASA Astrophysics Data System (ADS)

Smoak, Evan M.; Carlo, Andrew D.; Fowles, Catherine C.; Banerjee, Ipsita A.

2010-01-01

Gibberellins are a group of naturally occurring diterpenoid based phytohormones that play a vital role in plant growth and development. In this work, we have studied the self-assembly of gibberellic acid, a phytohormone, which belongs to the family of gibberellins, and designed amide derivatives of gibberellic acid (GA3) for the facile, green synthesis of gold nanoparticles. It was found that the derivatives self-assembled into nanofibers and nanoribbons in aqueous solutions at varying pH. Further, upon incubation with tetrachloroaurate, the self-assembled GA3-amide derivatives efficiently nucleated and formed gold nanoparticles when heated to 60 °C. Energy dispersive x-ray spectroscopy, transmission electron microscopy and scanning electron microscopy analyses revealed that uniform coatings of gold nanoparticles in the 10-20 nm range were obtained at low pH on the nanowire surfaces without the assistance of additional reducing agents. This simple method for the development of morphology controlled gold nanoparticles using a plant hormone derivative opens doors for a new class of plant biomaterials which can efficiently yield gold nanoparticles in an environmentally friendly manner. The gold encrusted nanowires formed using biomimetic methods may lead on to the formation of conductive nanowires, which may be useful for a wide range of applications such as in optoelectronics and sensors. Further, the spontaneous formation of highly organized nanostructures obtained from plant phytohormone derivatives such as gibberellic acid is of particular interest as it might help in further understanding the supramolecular assembly mechanism of more highly organized biological structures.

Pathogen exploitation of an abscisic acid- and jasmonate-inducible MAPK phosphatase and its interception by Arabidopsis immunity.

PubMed

Mine, Akira; Berens, Matthias L; Nobori, Tatsuya; Anver, Shajahan; Fukumoto, Kaori; Winkelmüller, Thomas M; Takeda, Atsushi; Becker, Dieter; Tsuda, Kenichi

2017-07-11

Phytopathogens promote virulence by, for example, exploiting signaling pathways mediated by phytohormones such as abscisic acid (ABA) and jasmonate (JA). Some plants can counteract pathogen virulence by invoking a potent form of immunity called effector-triggered immunity (ETI). Here, we report that ABA and JA mediate inactivation of the immune-associated MAP kinases (MAPKs), MPK3 and MPK6, in Arabidopsis thaliana ABA induced expression of genes encoding the protein phosphatases 2C (PP2Cs), HAI1 , HAI2 , and HAI3 through ABF/AREB transcription factors. These three HAI PP2Cs interacted with MPK3 and MPK6 and were required for ABA-mediated MPK3/MPK6 inactivation and immune suppression. The bacterial pathogen Pseudomonas syringae pv. tomato ( Pto ) DC3000 activates ABA signaling and produces a JA-mimicking phytotoxin, coronatine (COR), that promotes virulence. We found that Pto DC3000 induces HAI1 through COR-mediated activation of MYC2, a master transcription factor in JA signaling. HAI1 dephosphorylated MPK3 and MPK6 in vitro and was necessary for COR-mediated suppression of MPK3/MPK6 activation and immunity. Intriguingly, upon ETI activation, A. thaliana plants overcame the HAI1-dependent virulence of COR by blocking JA signaling. Finally, we showed conservation of induction of HAI PP2Cs by ABA and JA in other Brassicaceae species. Taken together, these results suggest that ABA and JA signaling pathways, which are hijacked by the bacterial pathogen, converge on the HAI PP2Cs that suppress activation of the immune-associated MAPKs. Also, our data unveil interception of JA-signaling activation as a host counterstrategy against the bacterial suppression of MAPKs during ETI.

Phytohormone abscisic acid elicits antinociceptive effects in rats through the activation of opioid and peroxisome proliferator-activated receptors β/δ.

PubMed

Mollashahi, Mahtab; Abbasnejad, Mehdi; Esmaeili-Mahani, Saeed

2018-08-05

The phytohormone abscisic acid exists in animal tissues particularly in the brain. However, its neurophysiological effects have not yet been fully clarified. This study was designed to evaluate the possible antinociceptive effects of abscisic acid on animal models of pain and determine its possible signaling mechanism. Tail-flick, hot-plate and formalin tests were used to assess the nociceptive threshold. All experiments were carried out on male Wistar rats. To determine the role of Peroxisome proliferator-activated receptor β/δ (PPARβ/δ) and opioid receptors on the induction of abscisic acid antinociception, specific antagonists were injected 15 min before abscisic acid. The data showed that abscisic acid (5, 10 and 15 µg/rat, i.c.v.) significantly decreased pain responses in formalin test. In addition, it could also produce dose-dependent antinociceptive effect in tail-flick and hot-plate tests. Administration of PPARβ/δ antagonist (GSK0660, 80 nM, i.c.v.) significantly attenuated the antinociceptive effect of abscisic acid in all tests. The antinociceptive effects of abscisic acid were completely inhibited by naloxone (6 µg, i.c.v.) during the time course of tail-flick and hot-plate tests. The results indicated that the central injection of abscisic acid has potent pain-relieving property which is mediated partly via the PPAR β/δ and opioid signaling. Copyright © 2018 Elsevier B.V. All rights reserved.

Nitrogen modulation of legume root architecture signaling pathways involves phytohormones and small regulatory molecules.

PubMed

Mohd-Radzman, Nadiatul A; Djordjevic, Michael A; Imin, Nijat

2013-10-01

Nitrogen, particularly nitrate is an important yield determinant for crops. However, current agricultural practice with excessive fertilizer usage has detrimental effects on the environment. Therefore, legumes have been suggested as a sustainable alternative for replenishing soil nitrogen. Legumes can uniquely form nitrogen-fixing nodules through symbiotic interaction with specialized soil bacteria. Legumes possess a highly plastic root system which modulates its architecture according to the nitrogen availability in the soil. Understanding how legumes regulate root development in response to nitrogen availability is an important step to improving root architecture. The nitrogen-mediated root development pathway starts with sensing soil nitrogen level followed by subsequent signal transduction pathways involving phytohormones, microRNAs and regulatory peptides that collectively modulate the growth and shape of the root system. This review focuses on the current understanding of nitrogen-mediated legume root architecture including local and systemic regulations by different N-sources and the modulations by phytohormones and small regulatory molecules.

Phytohormones in Japanese mugwort gall induction by a gall-inducing gall midge.

PubMed

Tanaka, Yuichiro; Okada, Koichi; Asami, Tadao; Suzuki, Yoshihito

2013-01-01

A variety of insect species induce galls on host plants. Liquid chromatographic/tandem mass spectrometric analyses showed that a gall midge (Rhopalomyia yomogicola) that induces galls on Artemisia princeps contained high levels of indole-3-acetic acid and cytokinins. The gall midge larvae also synthesized indole-3-acetic acid from tryptophan. Close observation of gall tissue sections indicated that the larval chamber was surrounded by layers of cells having secondary cell walls with extensive lignin deposition, except for the part of the gall that constituted the feeding nutritive tissue which was composed of small cells negatively stained for lignin. The differences between these two types of tissue were confirmed by an expression analysis of the genes involved in the synthesis of the secondary cell wall. Phytohormones may have functioned in maintaining the feeding part of the gall as fresh nutritive tissue. Together with the results in our previous study, those presented here suggest the importance of phytohormones in gall induction.

Mistletoe infestation mediates alteration of the phytohormone profile and anti-oxidative metabolism in bark and wood of its host Pinus sylvestris.

PubMed

Hu, Bin; Sakakibara, Hitoshi; Takebayashi, Yumiko; Peters, Franziska S; Schumacher, Jörg; Eiblmeier, Monika; Arab, Leila; Kreuzwieser, Jürgen; Polle, Andrea; Rennenberg, Heinz

2017-05-01

European mistletoe (Viscum album L.) has largely infested Central European forests and causes high mortality probability particularly in dry years. However, little information is available about the consequences of mistletoe infestation for metabolic processes in bark and wood of its host, despite their important roles in infestation defense. We analyzed the tissue hydration, carbohydrate composition, phytohormone profile, reactive oxygen species and anti-oxidant levels in bark and wood of Scots pines (Pinus sylvestris L.), as dependent on mistletoe infestation. As a consequence of mistletoe infestation, host bark and wood showed impaired hydration and reduced total carbon content. In the bark, soluble sugar and lignin contents increased, apparently at the expense of holo-cellulose. Hydrogen peroxide accumulation was accompanied by increased glutathione and decreased reduced ascorbic acid levels. Mistletoe infestation mediated alteration of the phytohormone profile in bark and wood of its host. Cytokinins, jasmonic acid and abscisic acid levels increased in both tissues, whereas salicylic acid and indole-3-acetic acid, which were only detected in the bark, declined. The present results show that mistletoe infestation affects both the host's anti-oxidative defense system and the phytohormone profile after establishment of the xylem tapping haustorium. The significance of these processes for the development of the woody mistletoe stem and the haustorium is discussed. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Phytohormone profile in Lactuca sativa and Brassica oleracea plants grown under Zn deficiency.

PubMed

Navarro-León, Eloy; Albacete, Alfonso; Torre-González, Alejandro de la; Ruiz, Juan M; Blasco, Begoña

2016-10-01

Phytohormones, structurally diverse compounds, are involved in multiple processes within plants, such as controlling plant growth and stress response. Zn is an essential micronutrient for plants and its deficiency causes large economic losses in crops. Therefore, the purpose of this study was to analyse the role of phytohormones in the Zn-deficiency response of two economically important species, i.e. Lactuca sativa and Brassica oleracea. For this, these two species were grown hydroponically with different Zn-application rates: 10 μM Zn as control and 0.1 μM Zn as deficiency treatment and phytohormone concentration was determined by U-HPLC-MS. Zn deficiency resulted in a substantial loss of biomass in L. sativa plants that was correlated with a decline in growth-promoting hormones such as indole-3-acetic acid (IAA), cytokinins (CKs), and gibberellins (GAs). However these hormones increased or stabilized their concentrations in B. oleracea and could help to maintain the biomass in this species. A lower concentration of stress-signaling hormones such as ethylene precursor aminocyclopropane-1-carboxylic acid (ACC), abscisic acid (ABA), salicylic acid (SA) and jasmonic acid (JA) and also CKs might be involved in Zn uptake in L. sativa while a rise in GA4, isopentenyl adenine (iP), and ACC and a fall in JA and SA might contribute to a better Zn-utilization efficiency (ZnUtE), as observed in B. oleracea plants. Copyright © 2016 Elsevier Ltd. All rights reserved.

Geometric analysis of Arabidopsis root apex reveals a new aspect of the ethylene signal transduction pathway in development

NASA Technical Reports Server (NTRS)

Cervantes, Emilio; Tocino, Angel

2005-01-01

Structurally, ethylene is the simplest phytohormone and regulates multiple aspects of plant growth and development. Its effects are mediated by a signal transduction cascade involving receptors, MAP kinases and transcription factors. Many morphological effects of ethylene in plant development, including root size, have been previously described. In this article a combined geometric and algebraic approach has been used to analyse the shape and the curvature in the root apex of Arabidopsis seedlings. The process requires the fitting of Bezier curves that reproduce the root apex shape, and the calculation of the corresponding curvatures. The application of the method has allowed us to identify significant differences in the root curvatures of ethylene insensitive mutants (ein2-1 and etr1-1) with respect to the wild-type Columbia.

Systemic control of cell division and endoreduplication by NAA and BAP by modulating CDKs in root tip cells of Allium cepa.

PubMed

Tank, Jigna G; Thaker, Vrinda S

2014-01-01

Molecular mechanism regulated by auxin and cytokinin during endoreduplication, cell division, and elongation process is studied by using Allium cepa roots as a model system. The activity of CDK genes modulated by auxin and cytokinin during cell division, elongation, and endoreduplication process is explained in this research work. To study the significance of auxin and cytokinin in the management of cell division and endoreduplication process in plant meristematic cells at molecular level endoreduplication was developed in root tips of Allium cepa by giving colchicine treatment. There were inhibition of vegetative growth, formation of c-tumor at root tip, and development of endoreduplicated cells after colchicine treatment. This c-tumor was further treated with NAA and BAP to reinitiate vegetative growth in roots. BAP gave positive response in reinitiation of vegetative growth of roots from center of c-tumor. However, NAA gave negative response in reinitiation of vegetative growth of roots from c-tumor. Further, CDKs gene expression analysis from normal, endoreduplicated, and phytohormone (NAA or BAP) treated root tip was done and remarkable changes in transcription level of CDK genes in normal, endoreduplicated, and phytohormones treated cells were observed.

Systemic Control of Cell Division and Endoreduplication by NAA and BAP by Modulating CDKs in Root Tip Cells of Allium cepa

PubMed Central

Tank, Jigna G.; Thaker, Vrinda S.

2014-01-01

Molecular mechanism regulated by auxin and cytokinin during endoreduplication, cell division, and elongation process is studied by using Allium cepa roots as a model system. The activity of CDK genes modulated by auxin and cytokinin during cell division, elongation, and endoreduplication process is explained in this research work. To study the significance of auxin and cytokinin in the management of cell division and endoreduplication process in plant meristematic cells at molecular level endoreduplication was developed in root tips of Allium cepa by giving colchicine treatment. There were inhibition of vegetative growth, formation of c-tumor at root tip, and development of endoreduplicated cells after colchicine treatment. This c-tumor was further treated with NAA and BAP to reinitiate vegetative growth in roots. BAP gave positive response in reinitiation of vegetative growth of roots from center of c-tumor. However, NAA gave negative response in reinitiation of vegetative growth of roots from c-tumor. Further, CDKs gene expression analysis from normal, endoreduplicated, and phytohormone (NAA or BAP) treated root tip was done and remarkable changes in transcription level of CDK genes in normal, endoreduplicated, and phytohormones treated cells were observed. PMID:24955358

Arabidopsis HECATE genes function in phytohormone control during gynoecium development.

PubMed

Schuster, Christoph; Gaillochet, Christophe; Lohmann, Jan U

2015-10-01

The fruit, which develops from the fertilised gynoecium formed in the innermost whorl of the flower, is the reproductive organ and one of the most complex structures of an angiosperm plant. Phytohormones play important roles during flower and fruit patterning, morphogenesis and growth, and there is emerging evidence for a cross-talk between different classes of plant hormones throughout these processes. Here, we show that the bHLH transcription factors HECATE 1 (HEC1), HEC2 and HEC3, which have previously been identified as essential components of transmitting tract formation, affect both auxin and cytokinin responses during reproductive tissue development. We find that HEC1 interacts with SPATULA (SPT) to control carpel fusion and that both transcription factors restrict sensitivity to cytokinin in the gynoecium. In addition, HEC1 is tightly integrated into the auxin-signalling network at the levels of biosynthesis, transport and transcriptional response. Based on this data, we propose that HEC1 acts as a local modulator of auxin and cytokinin responses to control gynoecium development in Arabidopsis. © 2015. Published by The Company of Biologists Ltd.

Phytohormonal Networks Promote Differentiation of Fiber Initials on Pre-Anthesis Cotton Ovules Grown In Vitro and In Planta

PubMed Central

Kim, Hee Jin; Hinchliffe, Doug J.; Triplett, Barbara A.; Chen, Z. Jeffrey; Stelly, David M.; Yeater, Kathleen M.; Moon, Hong S.; Gilbert, Matthew K.; Thyssen, Gregory N.; Turley, Rickie B.; Fang, David D.

2015-01-01

The number of cotton (Gossypium sp.) ovule epidermal cells differentiating into fiber initials is an important factor affecting cotton yield and fiber quality. Despite extensive efforts in determining the molecular mechanisms regulating fiber initial differentiation, only a few genes responsible for fiber initial differentiation have been discovered. To identify putative genes directly involved in the fiber initiation process, we used a cotton ovule culture technique that controls the timing of fiber initial differentiation by exogenous phytohormone application in combination with comparative expression analyses between wild type and three fiberless mutants. The addition of exogenous auxin and gibberellins to pre-anthesis wild type ovules that did not have visible fiber initials increased the expression of genes affecting auxin, ethylene, ABA and jasmonic acid signaling pathways within 1 h after treatment. Most transcripts expressed differentially by the phytohormone treatment in vitro were also differentially expressed in the ovules of wild type and fiberless mutants that were grown in planta. In addition to MYB25-like, a gene that was previously shown to be associated with the differentiation of fiber initials, several other differentially expressed genes, including auxin/indole-3-acetic acid (AUX/IAA) involved in auxin signaling, ACC oxidase involved in ethylene biosynthesis, and abscisic acid (ABA) 8'-hydroxylase an enzyme that controls the rate of ABA catabolism, were co-regulated in the pre-anthesis ovules of both wild type and fiberless mutants. These results support the hypothesis that phytohormonal signaling networks regulate the temporal expression of genes responsible for differentiation of cotton fiber initials in vitro and in planta. PMID:25927364

Pre-harvest UV-C irradiation triggers VOCs accumulation with alteration of antioxidant enzymes and phytohormones in strawberry leaves.

PubMed

Xu, Yanqun; Luo, Zisheng; Charles, Marie Thérèse; Rolland, Daniel; Roussel, Dominique

2017-11-01

Recent studies have highlighted the biological and physiological effects of pre-harvest ultraviolet (UV)-C treatment on growing plants. However, little is known about the involvement of volatile organic compounds (VOCs) and their response to this treatment. In this study, strawberry plants were exposed to three different doses of UV-C radiation for seven weeks (a low dose: 9.6kJm -2 ; a medium dose: 15kJm -2 ; and a high-dose: 29.4kJm -2 ). Changes in VOC profiles were investigated and an attempt was made to identify factors that may be involved in the regulation of these alterations. Principle compounds analysis revealed that VOC profiles of UV-C treated samples were significantly altered with 26 VOCs being the major contributors to segregation. Among them, 18 fatty acid-derived VOCs accumulated in plants that received high and medium dose of UV-C treatments with higher lipoxygenase and alcohol dehydrogenase activities. In treated samples, the activity of the antioxidant enzymes catalase and peroxidase was inhibited, resulting in a reduced antioxidant capacity and higher lipid peroxidation. Simultaneously, jasmonic acid level was 74% higher in the high-dose group while abscisic acid content was more than 12% lower in both the medium and high-dose UV-C treated samples. These results indicated that pre-harvest UV-C treatment stimulated the biosynthesis of fatty acid-derived VOCs in strawberry leaf tissue by upregulating the activity of enzymes of the LOX biosynthetic pathway and downregulating antioxidant enzyme activities. It is further suggested that the mechanisms underlying fatty acid-derived VOCs biosynthesis in UV-C treated strawberry leaves are associated with UV-C-induced changes in phytohormone profiles. Crown Copyright © 2017. Published by Elsevier GmbH. All rights reserved.

Salicylic Acid and Jasmonic Acid Pathways are Activated in Spatially Different Domains Around the Infection Site During Effector-Triggered Immunity in Arabidopsis thaliana.

PubMed

Betsuyaku, Shigeyuki; Katou, Shinpei; Takebayashi, Yumiko; Sakakibara, Hitoshi; Nomura, Nobuhiko; Fukuda, Hiroo

2018-01-01

The innate immune response is, in the first place, elicited at the site of infection. Thus, the host response can be different among the infected cells and the cells surrounding them. Effector-triggered immunity (ETI), a form of innate immunity in plants, is triggered by specific recognition between pathogen effectors and their corresponding plant cytosolic immune receptors, resulting in rapid localized cell death known as hypersensitive response (HR). HR cell death is usually limited to a few cells at the infection site, and is surrounded by a few layers of cells massively expressing defense genes such as Pathogenesis-Related Gene 1 (PR1). This virtually concentric pattern of the cellular responses in ETI is proposed to be regulated by a concentration gradient of salicylic acid (SA), a phytohormone accumulated around the infection site. Recent studies demonstrated that jasmonic acid (JA), another phytohormone known to be mutually antagonistic to SA in many cases, is also accumulated in and required for ETI, suggesting that ETI is a unique case. However, the molecular basis for this uniqueness remained largely to be solved. Here, we found that, using intravital time-lapse imaging, the JA signaling pathway is activated in the cells surrounding the central SA-active cells around the infection sites in Arabidopsis thaliana. This distinct spatial organization explains how these two phythormone pathways in a mutually antagonistic relationship can be activated simultaneously during ETI. Our results re-emphasize that the spatial consideration is a key strategy to gain mechanistic insights into the apparently complex signaling cross-talk in immunity. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.

Physiological effects of autotoxicity due to DHAP stress on Picea schrenkiana regeneration

PubMed Central

Yang, Li; Ruan, Xiao; Jiang, Dean; Zhang, Jianhong; Pan, Cunde; Wang, Qiang

2017-01-01

Picea Schrenkiana as one of the most important zonal vegetation was an endemic species in Middle Asia. Natural regeneration of P. Schrenkiana is a long existing problem troubling scientists. The autotoxicity of 3,4-dihydroxy-acetophenone (DHAP) was found to be a causative factor causing the failure of P. Schrenkiana natural regeneration. The effects of concentrations of DHAP treatment on the viability of root cell, activities of antioxidant enzymes and levels of P. Schrenkiana phytohormones were performed to disclose the physiological mechanism of DHAP autotoxicity. It was observed that high concentration of DHAP could inhibit the seed germination and seedling growth, but had a hormesis at low concentrations. Analyses showed that the root cells significantly lost their viability treated with high DHAP. The enzymes activities of seedlings were significantly stimulated by the treatment of 0.5 mM DHAP to give a transient increase and then decrease as DHAP concentration increased to 1.0 mM except for GR (glutathione reductase) in which DHAP treatment had little effect on its activity. Comparing with the control, an increase in the levels of phytohormones ZT (zeatin), GA3 (gibberellic acid) and IAA (indole acetic acid) was induced by the treatment of DHAP at low concentrations (0.1–0.25 mM), but the significant deficiency was found treated by high concentrations (0.5–1.0 mM). In addition, the ABA (abscisic acid) level increased in all experimental observations. These results suggested that DHAP significantly affected indices of growth and physiology, and provided some new information about different effect in P. Schrenkiana treated with DHAP. PMID:28481896

Investigation into the Physiological Significance of the Phytohormone Abscisic Acid in Perkinsus marinus, an Oyster Parasite Harboring a Nonphotosynthetic Plastid.

PubMed

Sakamoto, Hirokazu; Suzuki, Shigeo; Nagamune, Kisaburo; Kita, Kiyoshi; Matsuzaki, Motomichi

2017-07-01

Some organisms have retained plastids even after they have lost the ability to photosynthesize. Several studies of nonphotosynthetic plastids in apicomplexan parasites have shown that the isopentenyl pyrophosphate biosynthesis pathway in the organelle is essential for their survival. A phytohormone, abscisic acid, one of several compounds biosynthesized from isopentenyl pyrophosphate, regulates the parasite cell cycle. Thus, it is possible that the phytohormone is universally crucial, even in nonphotosynthetic plastids. Here, we examined this possibility using the oyster parasite Perkinsus marinus, which is a plastid-harboring cousin of apicomplexan parasites and has independently lost photosynthetic ability. Fluridone, an inhibitor of abscisic acid biosynthesis, blocked parasite growth and induced cell clustering. Nevertheless, abscisic acid and its intermediate carotenoids did not affect parasite growth or rescue the parasite from inhibition. Moreover, abscisic acid was not detected from the parasite using liquid chromatography mass spectrometry. Our findings show that abscisic acid does not play any significant roles in P. marinus. © 2016 The Authors. Journal of Eukaryotic Microbiology published by Wiley Periodicals, Inc. on behalf of International Society of Protistologists.

Phytohormone and assimilate profiles in emasculated flowers of the black locust (Robinia pseudoacacia) during development.

PubMed

Sun, Peng; Yuan, Cunquan; Dai, Li; Xi, Yang; Li, Yunfei; Hu, Ruiyang; Sun, Yuhan; Xu, Zhaohe; Li, Yun

2013-09-01

Emasculation and bagging of flowers, which are widely used in the controlled pollination of monoclinous plants, may induce premature senescence, flower abscission and low fruit set. To determine the mechanism responsible for these phenomena, levels of abscisic acid (ABA), jasmonic acid (JA), indole-3-acetic acid (IAA), ethylene, soluble sugars, reducing sugars and free amino acids in black locust (Robinia pseudoacacia) flowers subjected to different treatments were quantified at different developmental stages. The phytohormones and assimilates were also quantified in untreated flowers to investigate the presence of discernible patterns. The levels of ethylene and ABA in emasculated and bagged (EB) flowers increased prematurely compared with those of untreated flowers, whereas the content of reducing sugars in EB flowers decreased compared with that of untreated flowers. These results indicated that the premature increase in ethylene and ABA synthesis, and the decrease in reducing sugars content, in EB flowers may cause flower abscission and result in low fruit set, which may be relevant for assimilate applications and future research on the regulation of controlled pollinations with exogenous phytohormones.

Gene Networks and Functional Features of Gravitropic response in Rice Shoot Bases

NASA Astrophysics Data System (ADS)

Hu, Liwei; Zang, Aiping; Ai, Qianru; Chen, Haiying; Li, Lin; Li, Rui; Su, Feng; Chen, Xijiang; Rong, Hui; Dou, Xianying; Reinhold-Hurek, Barbara; Li, Qi; Cai, Weiming

To delineate key genes and the corresponding physiological functions as well as the coordina-tion of genes involved in the gravitropism of rice shoot bases, we used whole-genome microarray analysis of upper and lower parts of rice shoot bases at 0.5 h and 6 h after gravistimulation. And bio-information analysis was applied including GO-analysis, expression tendency and net-work analysis. In the lower shoot bases, auxin-mediated signaling pathway and glutathione transferase activity with the biggest enrichment were activated at 0.5 h, while cytokinin stimu-lus and photosynthesis were activated at 6 h. Meanwhile, several processes were suppressed in the lower shoot bases, including: xyloglucan:xyloglucosyl transferase activity, glucan metabolic processes, and ATPase activity at 0.5 h; and tRNA isopentenyltransferase activity, and chiti-nase activity, etc. at 6 h. Gene expression profile responding to gravistimulation suggested that the asymmetrically activation of several phytohormone signaling pathways including auxin, gib-berellin and cytokinin brassinolide ethylene and cytokinin-related genes were involved in the differentially growth between the upper and lower parts of rice shoot bases, and so do cell wall-related genes. Topological analysis of the coexpression networks revealed the core statue of AY177699.1(apetala3-like protein) and AK105103.1 at 0.5 h; AK062612.1 (ethylene response factor) and AK099932.1 (lectin-like receptor kinase 72) at 6 h. All the core factors have the function "response to endogenous stimulus". Additionally, AK108057.1(similar to germin-like protein precursor) was discovered as the most important core gene in the upper shoot bases in 6h after gravistimualtion while AK067424.1(cellulose synthase-like protein), AK120101.1 (Zinc finger, B-box domain containing protein) and CR278698 (ATPase associated with various cel-lular activities cellulose synthase-like protein) contribute equally to gravitropic response in the lower shoot bases.

Paper-based electroanalytical devices for in situ determination of salicylic acid in living tomato leaves.

PubMed

Sun, Li-Jun; Feng, Qiu-Mei; Yan, Yong-Feng; Pan, Zhong-Qin; Li, Xiao-Hui; Song, Feng-Ming; Yang, Haibing; Xu, Jing-Juan; Bao, Ning; Gu, Hai-Ying

2014-10-15

Detection of phytohormones in situ has gained significant attention due to their critical roles in regulating developmental processes and signaling for defenses in plants at low concentration. As one type of plant hormones, salicylic acid has recently been found to be one of pivotal signal molecules for physiological behaviors of plants. Here we report the application of paper-based electroanalytical devices for sensitively in situ detection of salicylic acid in tomato leaves with the sample volume of several microliters. Specifically, disposable working electrodes were fabricated by coating carbon tape with the mixture of multiwall carbon nanotubes and nafion. We observed that the treatment of the modified carbon tape electrodes with oxygen plasma could significantly improve electrochemical responses of salicylic acid. The tomato leaves had a punched hole of 1.5mm diameter to release salicylic acid with minor influence on continuous growth of tomatoes. By incorporating the tomato leaf with the paper-based analytical device, we were able to perform in situ determination of salicylic acid based on its electrocatalytic oxidation. Our experimental results demonstrated that the amounts of salicylic acid differed statistically in normal, phytoene desaturase (PDS) gene silent and diseased (infected by Botrytis cinerea) tomato leaves. By quantifying salicylic acid at the level of several nanograms in situ, the simple paper-based electroanalytical devices could potentially facilitate the study of defense mechanism of plants under biotic and abiotic stresses. This study might also provide a sensitive method with spatiotemporal resolution for mapping of chemicals released from living organisms. Copyright © 2014 Elsevier B.V. All rights reserved.

Genotypic characterization of Azotobacteria isolated from Argentinean soils and plant-growth-promoting traits of selected strains with prospects for biofertilizer production.

PubMed

Rubio, Esteban Julián; Montecchia, Marcela Susana; Tosi, Micaela; Cassán, Fabricio Darío; Perticari, Alejandro; Correa, Olga Susana

2013-01-01

The genetic diversity among 31 putative Azotobacter isolates obtained from agricultural and non-agricultural soils was assessed using rep-PCR genomic fingerprinting and identified to species level by ARDRA and partial 16S rRNA gene sequence analysis. High diversity was found among the isolates, identified as A. chroococcum, A. salinestris, and A. armeniacus. Selected isolates were characterized on the basis of phytohormone biosynthesis, nitrogenase activity, siderophore production, and phosphate solubilization. Indole-3 acetic-acid (IAA), gibberellin (GA3) and zeatin (Z) biosynthesis, nitrogenase activity, and siderophore production were found in all evaluated strains, with variation among them, but no phosphate solubilization was detected. Phytohormones excreted to the culture medium ranged in the following concentrations: 2.2-18.2 μ g IAA mL(-1), 0.3-0.7 μ g GA3 mL(-1), and 0.5-1.2 μ g Z mL(-1). Seed inoculations with further selected Azotobacter strains and treatments with their cell-free cultures increased the number of seminal roots and root hairs in wheat seedlings. This latter effect was mimicked by treatments with IAA-pure solutions, but it was not related to bacterial root colonization. Our survey constitutes a first approach to the knowledge of Azotobacter species inhabiting Argentinean soils in three contrasting geographical regions. Moreover, this phenotypic characterization constitutes an important contribution to the selection of Azotobacter strains for biofertilizer formulations.

Genotypic Characterization of Azotobacteria Isolated from Argentinean Soils and Plant-Growth-Promoting Traits of Selected Strains with Prospects for Biofertilizer Production

PubMed Central

Rubio, Esteban Julián; Cassán, Fabricio Darío

2013-01-01

The genetic diversity among 31 putative Azotobacter isolates obtained from agricultural and non-agricultural soils was assessed using rep-PCR genomic fingerprinting and identified to species level by ARDRA and partial 16S rRNA gene sequence analysis. High diversity was found among the isolates, identified as A. chroococcum, A. salinestris, and A. armeniacus. Selected isolates were characterized on the basis of phytohormone biosynthesis, nitrogenase activity, siderophore production, and phosphate solubilization. Indole-3 acetic-acid (IAA), gibberellin (GA3) and zeatin (Z) biosynthesis, nitrogenase activity, and siderophore production were found in all evaluated strains, with variation among them, but no phosphate solubilization was detected. Phytohormones excreted to the culture medium ranged in the following concentrations: 2.2–18.2 μg IAA mL−1, 0.3–0.7 μg GA3 mL−1, and 0.5–1.2 μg Z mL−1. Seed inoculations with further selected Azotobacter strains and treatments with their cell-free cultures increased the number of seminal roots and root hairs in wheat seedlings. This latter effect was mimicked by treatments with IAA-pure solutions, but it was not related to bacterial root colonization. Our survey constitutes a first approach to the knowledge of Azotobacter species inhabiting Argentinean soils in three contrasting geographical regions. Moreover, this phenotypic characterization constitutes an important contribution to the selection of Azotobacter strains for biofertilizer formulations. PMID:24302859

Interplay between sugar and hormone signaling pathways modulate floral signal transduction

PubMed Central

Matsoukas, Ianis G.

2014-01-01

NOMENCLATURE The following nomenclature will be used in this article: Names of genes are written in italicized upper-case letters, e.g., ABI4.Names of proteins are written in non-italicized upper-case letters, e.g., ABI4.Names of mutants are written in italicized lower-case letters, e.g., abi4. The juvenile-to-adult and vegetative-to-reproductive phase transitions are major determinants of plant reproductive success and adaptation to the local environment. Understanding the intricate molecular genetic and physiological machinery by which environment regulates juvenility and floral signal transduction has significant scientific and economic implications. Sugars are recognized as important regulatory molecules that regulate cellular activity at multiple levels, from transcription and translation to protein stability and activity. Molecular genetic and physiological approaches have demonstrated different aspects of carbohydrate involvement and its interactions with other signal transduction pathways in regulation of the juvenile-to-adult and vegetative-to-reproductive phase transitions. Sugars regulate juvenility and floral signal transduction through their function as energy sources, osmotic regulators and signaling molecules. Interestingly, sugar signaling has been shown to involve extensive connections with phytohormone signaling. This includes interactions with phytohormones that are also important for the orchestration of developmental phase transitions, including gibberellins, abscisic acid, ethylene, and brassinosteroids. This article highlights the potential roles of sugar-hormone interactions in regulation of floral signal transduction, with particular emphasis on Arabidopsis thaliana mutant phenotypes, and suggests possible directions for future research. PMID:25165468

Interplay between sugar and hormone signaling pathways modulate floral signal transduction.

PubMed

Matsoukas, Ianis G

2014-01-01

NOMENCLATURE The following nomenclature will be used in this article: Names of genes are written in italicized upper-case letters, e.g., ABI4.Names of proteins are written in non-italicized upper-case letters, e.g., ABI4.Names of mutants are written in italicized lower-case letters, e.g., abi4. The juvenile-to-adult and vegetative-to-reproductive phase transitions are major determinants of plant reproductive success and adaptation to the local environment. Understanding the intricate molecular genetic and physiological machinery by which environment regulates juvenility and floral signal transduction has significant scientific and economic implications. Sugars are recognized as important regulatory molecules that regulate cellular activity at multiple levels, from transcription and translation to protein stability and activity. Molecular genetic and physiological approaches have demonstrated different aspects of carbohydrate involvement and its interactions with other signal transduction pathways in regulation of the juvenile-to-adult and vegetative-to-reproductive phase transitions. Sugars regulate juvenility and floral signal transduction through their function as energy sources, osmotic regulators and signaling molecules. Interestingly, sugar signaling has been shown to involve extensive connections with phytohormone signaling. This includes interactions with phytohormones that are also important for the orchestration of developmental phase transitions, including gibberellins, abscisic acid, ethylene, and brassinosteroids. This article highlights the potential roles of sugar-hormone interactions in regulation of floral signal transduction, with particular emphasis on Arabidopsis thaliana mutant phenotypes, and suggests possible directions for future research.

An efficient cardiac mapping strategy for radiofrequency catheter ablation with active learning.

PubMed

Feng, Yingjing; Guo, Ziyan; Dong, Ziyang; Zhou, Xiao-Yun; Kwok, Ka-Wai; Ernst, Sabine; Lee, Su-Lin

2017-07-01

A major challenge in radiofrequency catheter ablation procedures is the voltage and activation mapping of the endocardium, given a limited mapping time. By learning from expert interventional electrophysiologists (operators), while also making use of an active-learning framework, guidance on performing cardiac voltage mapping can be provided to novice operators or even directly to catheter robots. A learning from demonstration (LfD) framework, based upon previous cardiac mapping procedures performed by an expert operator, in conjunction with Gaussian process (GP) model-based active learning, was developed to efficiently perform voltage mapping over right ventricles (RV). The GP model was used to output the next best mapping point, while getting updated towards the underlying voltage data pattern as more mapping points are taken. A regularized particle filter was used to keep track of the kernel hyperparameter used by GP. The travel cost of the catheter tip was incorporated to produce time-efficient mapping sequences. The proposed strategy was validated on a simulated 2D grid mapping task, with leave-one-out experiments on 25 retrospective datasets, in an RV phantom using the Stereotaxis Niobe ® remote magnetic navigation system, and on a tele-operated catheter robot. In comparison with an existing geometry-based method, regression error was reduced and was minimized at a faster rate over retrospective procedure data. A new method of catheter mapping guidance has been proposed based on LfD and active learning. The proposed method provides real-time guidance for the procedure, as well as a live evaluation of mapping sufficiency.

Differential effects of plant ontogeny and damage type on phloem and foliage monoterpenes in jack pine (Pinus banksiana).

PubMed

Erbilgin, Nadir; Colgan, L Jessie

2012-08-01

Coniferous trees have both constitutive and inducible defences that deter or kill herbivores and pathogens. We investigated constitutive and induced monoterpene responses of jack pine (Pinus banksiana Lamb.) to a number of damage types: a fungal associate of the mountain pine beetle (Dendroctonus ponderosae Hopkins), Grosmannia clavigera (Robinson-Jeffrey & R.W. Davidson); two phytohormones, methyl jasmonate (MJ) and methyl salicylate (MS); simulated herbivory; and mechanical wounding. We only included the fungal, MJ and mechanical wounding treatments in the field experiments while all treatments were part of the greenhouse studies. We focused on both constitutive and induced responses between juvenile and mature jack pine trees and differences in defences between phloem and needles. We found that phytohormone applications and fungal inoculation resulted in the greatest increase in monoterpenes in both juvenile and mature trees. Additionally, damage types differentially affected the proportions of individual monoterpenes: MJ-treated mature trees had higher myrcene and β-pinene than fungal-inoculated mature trees, while needles of juveniles inoculated with the fungus contained higher limonene than MJ- or MS-treated juveniles. Although the constitutive monoterpenes were higher in the phloem of juveniles than mature jack pine trees, the phloem of mature trees had a much higher magnitude of induction. Further, induced monoterpene concentrations in juveniles were higher in phloem than in needles. There was no difference in monoterpene concentration between phytohormone applications and G. clavigera inoculation in mature trees, while in juvenile trees MJ was different from both G. clavigera and simulated herbivory in needle monoterpenes, but there was no difference between phytohormone applications and simulated herbivory in the phloem.

Integrated Analysis of the Effects of Cold and Dehydration on Rice Metabolites, Phytohormones, and Gene Transcripts1[W][OPEN

PubMed Central

Maruyama, Kyonoshin; Urano, Kaoru; Yoshiwara, Kyouko; Morishita, Yoshihiko; Sakurai, Nozomu; Suzuki, Hideyuki; Kojima, Mikiko; Sakakibara, Hitoshi; Shibata, Daisuke; Saito, Kazuki; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko

2014-01-01

Correlations between gene expression and metabolite/phytohormone levels under abiotic stress conditions have been reported for Arabidopsis (Arabidopsis thaliana). However, little is known about these correlations in rice (Oryza sativa ‘Nipponbare’), despite its importance as a model monocot. We performed an integrated analysis to clarify the relationships among cold- and dehydration-responsive metabolites, phytohormones, and gene transcription in rice. An integrated analysis of metabolites and gene expression indicated that several genes encoding enzymes involved in starch degradation, sucrose metabolism, and the glyoxylate cycle are up-regulated in rice plants exposed to cold or dehydration and that these changes are correlated with the accumulation of glucose (Glc), fructose, and sucrose. In particular, high expression levels of genes encoding isocitrate lyase and malate synthase in the glyoxylate cycle correlate with increased Glc levels in rice, but not in Arabidopsis, under dehydration conditions, indicating that the regulation of the glyoxylate cycle may be involved in Glc accumulation under dehydration conditions in rice but not Arabidopsis. An integrated analysis of phytohormones and gene transcripts revealed an inverse relationship between abscisic acid (ABA) signaling and cytokinin (CK) signaling under cold and dehydration stresses; these stresses increase ABA signaling and decrease CK signaling. High levels of Oryza sativa 9-cis-epoxycarotenoid dioxygenase transcripts correlate with ABA accumulation, and low levels of Cytochrome P450 (CYP) 735A transcripts correlate with decreased levels of a CK precursor in rice. This reduced expression of CYP735As occurs in rice but not Arabidopsis. Therefore, transcriptional regulation of CYP735As might be involved in regulating CK levels under cold and dehydration conditions in rice but not Arabidopsis. PMID:24515831

Physiological and Proteomic Analysis of the Rice Mutant cpm2 Suggests a Negative Regulatory Role of Jasmonic Acid in Drought Tolerance

PubMed Central

Dhakarey, Rohit; Raorane, Manish L.; Treumann, Achim; Peethambaran, Preshobha K.; Schendel, Rachel R.; Sahi, Vaidurya P.; Hause, Bettina; Bunzel, Mirko; Henry, Amelia; Kohli, Ajay; Riemann, Michael

2017-01-01

It is widely known that numerous adaptive responses of drought-stressed plants are stimulated by chemical messengers known as phytohormones. Jasmonic acid (JA) is one such phytohormone. But there are very few reports revealing its direct implication in drought related responses or its cross-talk with other phytohormones. In this study, we compared the morpho-physiological traits and the root proteome of a wild type (WT) rice plant with its JA biosynthesis mutant coleoptile photomorphogenesis 2 (cpm2), disrupted in the allene oxide cyclase (AOC) gene, for insights into the role of JA under drought. The mutant had higher stomatal conductance, higher water use efficiency and higher shoot ABA levels under severe drought as compared to the WT. Notably, roots of cpm2 were better developed compared to the WT under both, control and drought stress conditions. Root proteome was analyzed using the Tandem Mass Tag strategy to better understand this difference at the molecular level. Expectedly, AOC was unique but notably highly abundant under drought in the WT. Identification of other differentially abundant proteins (DAPs) suggested increased energy metabolism (i.e., increased mobilization of resources) and reactive oxygen species scavenging in cpm2 under drought. Additionally, various proteins involved in secondary metabolism, cell growth and cell wall synthesis were also more abundant in cpm2 roots. Proteome-guided transcript, metabolite, and histological analyses provided further insights into the favorable adaptations and responses, most likely orchestrated by the lack of JA, in the cpm2 roots. Our results in cpm2 are discussed in the light of JA crosstalk to other phytohormones. These results together pave the path for understanding the precise role of JA during drought stress in rice. PMID:29250082

Endophytic Paecilomyces formosus LHL10 Augments Glycine max L. Adaptation to Ni-Contamination through Affecting Endogenous Phytohormones and Oxidative Stress

PubMed Central

Bilal, Saqib; Khan, Abdul L.; Shahzad, Raheem; Asaf, Sajjad; Kang, Sang-Mo; Lee, In-Jung

2017-01-01

This study investigated the Ni-removal efficiency of phytohormone-producing endophytic fungi Penicillium janthinellum, Paecilomyces formosus, Exophiala sp., and Preussia sp. Among four different endophytes, P. formosus LHL10 was able to tolerate up to 1 mM Ni in contaminated media as compared to copper and cadmium. P. formosus LHL10 was further assessed for its potential to enhance the phytoremediation of Glycine max (soybean) in response to dose-dependent increases in soil Ni (0.5, 1.0, and 5.0 mM). Inoculation with P. formosus LHL10 significantly increased plant biomass and growth attributes as compared to non-inoculated control plants with or without Ni contamination. LHL10 enhanced the translocation of Ni from the root to the shoot as compared to the control. In addition, P. formosus LHL10 modulated the physio-chemical apparatus of soybean plants during Ni-contamination by reducing lipid peroxidation and the accumulation of linolenic acid, glutathione, peroxidase, polyphenol oxidase, catalase, and superoxide dismutase. Stress-responsive phytohormones such as abscisic acid and jasmonic acid were significantly down-regulated in fungal-inoculated soybean plants under Ni stress. LHL10 Ni-remediation potential can be attributed to its phytohormonal synthesis related genetic makeup. RT-PCR analysis showed the expression of indole-3-acetamide hydrolase, aldehyde dehydrogenase for indole-acetic acid and geranylgeranyl-diphosphate synthase, ent-kaurene oxidase (P450-4), C13-oxidase (P450-3) for gibberellins synthesis. In conclusion, the inoculation of P. formosus can significantly improve plant growth in Ni-polluted soils, and assist in improving the phytoremediation abilities of economically important crops. PMID:28611799

Endophytic Paecilomyces formosus LHL10 Augments Glycine max L. Adaptation to Ni-Contamination through Affecting Endogenous Phytohormones and Oxidative Stress.

PubMed

Bilal, Saqib; Khan, Abdul L; Shahzad, Raheem; Asaf, Sajjad; Kang, Sang-Mo; Lee, In-Jung

2017-01-01

This study investigated the Ni-removal efficiency of phytohormone-producing endophytic fungi Penicillium janthinellum , Paecilomyces formosus , Exophiala sp., and Preussia sp. Among four different endophytes, P. formosus LHL10 was able to tolerate up to 1 mM Ni in contaminated media as compared to copper and cadmium. P. formosus LHL10 was further assessed for its potential to enhance the phytoremediation of Glycine max (soybean) in response to dose-dependent increases in soil Ni (0.5, 1.0, and 5.0 mM). Inoculation with P. formosus LHL10 significantly increased plant biomass and growth attributes as compared to non-inoculated control plants with or without Ni contamination. LHL10 enhanced the translocation of Ni from the root to the shoot as compared to the control. In addition, P. formosus LHL10 modulated the physio-chemical apparatus of soybean plants during Ni-contamination by reducing lipid peroxidation and the accumulation of linolenic acid, glutathione, peroxidase, polyphenol oxidase, catalase, and superoxide dismutase. Stress-responsive phytohormones such as abscisic acid and jasmonic acid were significantly down-regulated in fungal-inoculated soybean plants under Ni stress. LHL10 Ni-remediation potential can be attributed to its phytohormonal synthesis related genetic makeup. RT-PCR analysis showed the expression of indole-3-acetamide hydrolase , aldehyde dehydrogenase for indole-acetic acid and geranylgeranyl-diphosphate synthase , ent-kaurene oxidase ( P450-4 ), C13-oxidase ( P450-3 ) for gibberellins synthesis. In conclusion, the inoculation of P. formosus can significantly improve plant growth in Ni-polluted soils, and assist in improving the phytoremediation abilities of economically important crops.

Unveiling the molecular mechanism of brassinosteroids: Insights from structure-based molecular modeling studies.

PubMed

Lei, Beilei; Liu, Jiyuan; Yao, Xiaojun

2015-12-01

Brassinosteroid (BR) phytohormones play indispensable roles in plant growth and development. Brassinolide (BL) and 24-epibrassinolide (24-epiBL) are the most active ones among the BRs reported thus far. Unfortunately, the extremely low natural content and intricate synthesis process limit their popularization in agricultural production. Earlier reports to discover alternative compounds have resulted in molecules with nearly same scaffold structure and without diversity in chemical space. In the present study, receptors structure based BRs regulation mechanism was analyzed. First, we examined the detailed binding interactions and their dynamic stability between BL and its receptor BRI1 and co-receptor BAK1. Then, the binding modes and binding free energies for 24-epiBL and a series of representative BRs binding with BRI1 and BRI1-BAK1 were carried out by molecular docking, energy minimization and MM-PBSA free energy calculation. The obtained binding structures and energetic results provided vital insights into the structural factors affecting the activity from both receptors and BRs aspects. Subsequently, the obtained knowledge will serve as valuable guidance to build pharmacophore models for rational screening of new scaffold alternative BRs. Copyright © 2015 Elsevier Inc. All rights reserved.

Hydrogen bonding in phytohormone-auxin (IAA) and its derivatives

NASA Astrophysics Data System (ADS)

Kojić-Prodić, Biserka; Kroon, Jan; Puntarec, Vitomir

1994-06-01

The significant importance of hydrogen bonds in biological structures and enzymatic reactions has been demonstrated in many examples. As a part of the molecular recognition study of auxins (plant growth hormones) the influence of hydrogen bonding on molecular conformation, particularly of the carboxyl group, which is one of the biologically active ligand sites, has been studied by X-ray diffraction and computational chemistry methods. The survey includes about 40 crystal structures of free auxins such as indol-3-ylacetic acid and its n-alkylated and halogenated derivatives but also bound auxins such as N-(indol-3-ylacetyl)- L-amino acids, and carbohydrate conjugates. The study includes hydrogen bonds of the NH⋯O and OH⋯O types. The classification of hydrogen bond patterns based on the discrimination between the centrosymmetric and non-centrosymmetric space groups and several examples of hydrogen bond systematics on graph set analysis are also shown.

The Garlic Allelochemical Diallyl Disulfide Affects Tomato Root Growth by Influencing Cell Division, Phytohormone Balance and Expansin Gene Expression

PubMed Central

Cheng, Fang; Cheng, Zhihui; Meng, Huanwen; Tang, Xiangwei

2016-01-01

Diallyl disulfide (DADS) is a volatile organosulfur compound derived from garlic (Allium sativum L.), and it is known as an allelochemical responsible for the strong allelopathic potential of garlic. The anticancer properties of DADS have been studied in experimental animals and various types of cancer cells, but to date, little is known about its mode of action as an allelochemical at the cytological level. The current research presents further studies on the effects of DADS on tomato (Solanum lycopersicum L.) seed germination, root growth, mitotic index, and cell size in root meristem, as well as the phytohormone levels and expression profile of auxin biosynthesis genes (FZYs), auxin transport genes (SlPINs), and expansin genes (EXPs) in tomato root. The results showed a biphasic, dose-dependent effect on tomato seed germination and root growth under different DADS concentrations. Lower concentrations (0.01–0.62 mM) of DADS significantly promoted root growth, whereas higher levels (6.20–20.67 mM) showed inhibitory effects. Cytological observations showed that the cell length of root meristem was increased and that the mitotic activity of meristematic cells in seedling root tips was enhanced at lower concentrations of DADS. In contrast, DADS at higher concentrations inhibited root growth by affecting both the length and division activity of meristematic cells. However, the cell width of the root meristem was not affected. Additionally, DADS increased the IAA and ZR contents of seedling roots in a dose-dependent manner. The influence on IAA content may be mediated by the up-regulation of FZYs and PINs. Further investigation into the underlying mechanism revealed that the expression levels of tomato EXPs were significantly affected by DADS. The expression levels of EXPB2 and beta-expansin precursor were increased after 3 d, and those of EXP1, EXPB3 and EXLB1 were increased after 5 d of DADS treatment (0.41 mM). This result suggests that tomato root growth may be regulated by multiple expansin genes at different developmental stages. Therefore, we conclude that the effects of DADS on the root growth of tomato seedlings are likely caused by changes associated with cell division, phytohormones, and the expression levels of expansin genes. PMID:27555862

Monitoring intra- and extracellular redox capacity of intact barley aleurone layers responding to phytohormones.

PubMed

Mark, Christina; Zór, Kinga; Heiskanen, Arto; Dufva, Martin; Emnéus, Jenny; Finnie, Christine

2016-12-15

Redox regulation is important for numerous processes in plant cells including abiotic stress, pathogen defence, tissue development, seed germination and programmed cell death. However, there are few methods allowing redox homeostasis to be addressed in whole plant cells, providing insight into the intact in vivo environment. An electrochemical redox assay that applies the menadione-ferricyanide double mediator is used to assess changes in the intracellular and extracellular redox environment in living aleurone layers of barley (Hordeum vulgare cv. Himalaya) grains, which respond to the phytohormones gibberellic acid and abscisic acid. Gibberellic acid is shown to elicit a mobilisation of electrons as detected by an increase in the reducing capacity of the aleurone layers. By taking advantage of the membrane-permeable menadione/menadiol redox pair to probe the membrane-impermeable ferricyanide/ferrocyanide redox pair, the mobilisation of electrons was dissected into an intracellular and an extracellular, plasma membrane-associated component. The intracellular and extracellular increases in reducing capacity were both suppressed when the aleurone layers were incubated with abscisic acid. By probing redox levels in intact plant tissue, the method provides a complementary approach to assays of reactive oxygen species and redox-related enzyme activities in tissue extracts. Copyright © 2016 Elsevier Inc. All rights reserved.

Stem development through vascular tissues: EPFL-ERECTA family signaling that bounces in and out of phloem.

PubMed

Tameshige, Toshiaki; Ikematsu, Shuka; Torii, Keiko U; Uchida, Naoyuki

2017-01-01

Plant cells communicate with each other using a variety of signaling molecules. Recent studies have revealed that various types of secreted peptides, as well as phytohormones known since long ago, mediate cell-cell communication in diverse contexts of plant life. These peptides affect cellular activities, such as proliferation and cell fate decisions, through their perception by cell surface receptors located on the plasma membrane of target cells. ERECTA (ER), an Arabidopsis thaliana receptor kinase gene, was first identified as a stem growth regulator, and since then an increasing number of studies have shown that ER is involved in a wide range of developmental and physiological processes. In particular, molecular functions of ER have been extensively studied in stomatal patterning. Furthermore, the importance of ER signaling in vascular tissues of inflorescence stems, especially in phloem cells, has recently been highlighted. In this review article, first we briefly summarize the history of ER research including studies on stomatal development, then introduce ER functions in vascular tissues, and discuss its interactions with phytohormones and other receptor kinase signaling pathways. Future questions and challenges will also be addressed. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Cyanobacteria-mediated phenylpropanoids and phytohormones in rice (Oryza sativa) enhance plant growth and stress tolerance.

PubMed

Singh, Dhananjaya P; Prabha, Ratna; Yandigeri, Mahesh S; Arora, Dilip K

2011-11-01

Phenylpropanoids, flavonoids and plant growth regulators in rice (Oryza sativa) variety (UPR 1823) inoculated with different cyanobacterial strains namely Anabaena oryzae, Anabaena doliolum, Phormidium fragile, Calothrix geitonos, Hapalosiphon intricatus, Aulosira fertilissima, Tolypothrix tenuis, Oscillatoria acuta and Plectonema boryanum were quantified using HPLC in pot conditions after 15 and 30 days. Qualitative analysis of the induced compounds using reverse phase HPLC and further confirmation with LC-MS/MS showed consistent accumulation of phenolic acids (gallic, gentisic, caffeic, chlorogenic and ferulic acids), flavonoids (rutin and quercetin) and phytohormones (indole acetic acid and indole butyric acid) in rice leaves. Plant growth promotion (shoot, root length and biomass) was positively correlated with total protein and chlorophyll content of leaves. Enzyme activity of peroxidase and phenylalanine ammonia lyase and total phenolic content was fairly high in rice leaves inoculated with O. acuta and P. boryanum after 30 days. Differential systemic accumulation of phenylpropanoids in plant leaves led us to conclude that cyanobacterial inoculation correlates positively with plant growth promotion and stress tolerance in rice. Furthermore, the study helped in deciphering possible mechanisms underlying plant growth promotion and stress tolerance in rice following cyanobacterial inoculation and indicated the less explored avenue of cyanobacterial colonization in stress tolerance against abiotic stress.

Role of stress-related hormones in plant defence during early infection of the cyst nematode Heterodera schachtii in Arabidopsis

PubMed Central

Kammerhofer, Nina; Radakovic, Zoran; Regis, Jully M A; Dobrev, Petre; Vankova, Radomira; Grundler, Florian M W; Siddique, Shahid; Hofmann, Julia; Wieczorek, Krzysztof

2015-01-01

Heterodera schachtii, a plant-parasitic cyst nematode, invades host roots and induces a specific syncytial feeding structure, from which it withdraws all required nutrients, causing severe yield losses. The system H. schachtii–Arabidopsis is an excellent research model for investigating plant defence mechanisms. Such responses are suppressed in well-established syncytia, whereas they are induced during early parasitism. However, the mechanisms by which the defence responses are modulated and the role of phytohormones are largely unknown. The aim of this study was to elucidate the role of hormone-based defence responses at the onset of nematode infection. First, concentrations of main phytohormones were quantified and the expression of several hormone-related genes was analysed using quantitative real-time (qRT)-PCR or GeneChip. Further, the effects of individual hormones were evaluated via nematode attraction and infection assays using plants with altered endogenous hormone concentrations. Our results suggest a pivotal and positive role for ethylene during nematode attraction, whereas jasmonic acid triggers early defence responses against H. schachtii. Salicylic acid seems to be a negative regulator during later syncytium and female development. We conclude that nematodes are able to impose specific changes in hormone pools, thus modulating hormone-based defence and signal transduction in strict dependence on their parasitism stage. PMID:25825039

Role of stress-related hormones in plant defence during early infection of the cyst nematode Heterodera schachtii in Arabidopsis.

PubMed

Kammerhofer, Nina; Radakovic, Zoran; Regis, Jully M A; Dobrev, Petre; Vankova, Radomira; Grundler, Florian M W; Siddique, Shahid; Hofmann, Julia; Wieczorek, Krzysztof

2015-08-01

Heterodera schachtii, a plant-parasitic cyst nematode, invades host roots and induces a specific syncytial feeding structure, from which it withdraws all required nutrients, causing severe yield losses. The system H. schachtii-Arabidopsis is an excellent research model for investigating plant defence mechanisms. Such responses are suppressed in well-established syncytia, whereas they are induced during early parasitism. However, the mechanisms by which the defence responses are modulated and the role of phytohormones are largely unknown. The aim of this study was to elucidate the role of hormone-based defence responses at the onset of nematode infection. First, concentrations of main phytohormones were quantified and the expression of several hormone-related genes was analysed using quantitative real-time (qRT)-PCR or GeneChip. Further, the effects of individual hormones were evaluated via nematode attraction and infection assays using plants with altered endogenous hormone concentrations. Our results suggest a pivotal and positive role for ethylene during nematode attraction, whereas jasmonic acid triggers early defence responses against H. schachtii. Salicylic acid seems to be a negative regulator during later syncytium and female development. We conclude that nematodes are able to impose specific changes in hormone pools, thus modulating hormone-based defence and signal transduction in strict dependence on their parasitism stage. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Multiple phytohormone signalling pathways modulate susceptibility of tomato plants to Alternaria alternata f. sp. lycopersici

PubMed Central

Jia, Chengguo; Zhang, Liping; Wang, Qiaomei

2013-01-01

Three phytohormone molecules – ethylene (ET), jasmonic acid (JA) and salicylic acid (SA) – play key roles in mediating disease response to necrotrophic fungal pathogens. This study investigated the roles of the ET, JA, and SA pathways as well as their crosstalk during the interaction between tomato (Solanum lycopersicum) plants and a necrotrophic fungal pathogen Alternaria alternata f. sp. lycopersici (AAL). Both the ET and JASMONIC ACID INSENSITIVE1 (JAI1) receptor-dependent JA signalling pathways are necessary for susceptibility, while SA response promotes resistance to AAL infection. In addition, the role of JA in susceptibility to AAL is partly dependent on ET biosynthesis and perception, while the SA pathway enhances resistance to AAL and antagonizes the ET response. Based on these results, it is proposed that ET, JA, and SA each on their own can influence the susceptibility of tomato to AAL. Furthermore, the functions of JA and SA in susceptibility to the pathogen are correlated with the enhanced or decreased action of ET, respectively. This study has revealed the functional relationship among the three key hormone pathways in tomato defence against AAL. PMID:23264518

Partnering with Youth to Map Their Neighborhood Environments: A Multi-Layered GIS Approach

PubMed Central

Topmiller, Michael; Jacquez, Farrah; Vissman, Aaron T.; Raleigh, Kevin; Miller-Francis, Jenni

2014-01-01

Mapping approaches offer great potential for community-based participatory researchers interested in displaying youth perceptions and advocating for change. We describe a multi-layered approach for gaining local knowledge of neighborhood environments that engages youth as co-researchers and active knowledge producers. By integrating geographic information systems (GIS) with environmental audits, an interactive focus group, and sketch mapping, the approach provides a place-based understanding of physical activity resources from the situated experience of youth. Youth report safety and a lack of recreational resources as inhibiting physical activity. Maps reflecting youth perceptions aid policy-makers in making place-based improvements for youth neighborhood environments. PMID:25423245

Comparing Two Forms of Concept Map Critique Activities to Facilitate Knowledge Integration Processes in Evolution Education

ERIC Educational Resources Information Center

Schwendimann, Beat A.; Linn, Marcia C.

2016-01-01

Concept map activities often lack a subsequent revision step that facilitates knowledge integration. This study compares two collaborative critique activities using a Knowledge Integration Map (KIM), a form of concept map. Four classes of high school biology students (n?=?81) using an online inquiry-based learning unit on evolution were assigned…

Spatial and temporal expression patterns of auxin response transcription factors in the syncytium induced by the beet cyst nematode Heterodera schachtii in Arabidopsis.

PubMed

Hewezi, Tarek; Piya, Sarbottam; Richard, Geoffrey; Rice, J Hollis

2014-09-01

Plant-parasitic cyst nematodes induce the formation of a multinucleated feeding site in the infected root, termed the syncytium. Recent studies point to key roles of the phytohormone auxin in the regulation of gene expression and establishment of the syncytium. Nevertheless, information about the spatiotemporal expression patterns of the transcription factors that mediate auxin transcriptional responses during syncytium formation is limited. Here, we provide a gene expression map of 22 auxin response factors (ARFs) during the initiation, formation and maintenance stages of the syncytium induced by the cyst nematode Heterodera schachtii in Arabidopsis. We observed distinct and overlapping expression patterns of ARFs throughout syncytium development phases. We identified a set of ARFs whose expression is predominantly located inside the developing syncytium, whereas others are expressed in the neighbouring cells, presumably to initiate specific transcriptional programmes required for their incorporation within the developing syncytium. Our analyses also point to a role of certain ARFs in determining the maximum size of the syncytium. In addition, several ARFs were found to be highly expressed in fully developed syncytia, suggesting a role in maintaining the functional phenotype of mature syncytia. The dynamic distribution and overlapping expression patterns of various ARFs seem to be essential characteristics of ARF activity during syncytium development. © 2014 BSPP AND JOHN WILEY & SONS LTD.

Comprehensive Genome-Wide Survey, Genomic Constitution and Expression Profiling of the NAC Transcription Factor Family in Foxtail Millet (Setaria italica L.)

PubMed Central

Puranik, Swati; Sahu, Pranav Pankaj; Mandal, Sambhu Nath; B., Venkata Suresh; Parida, Swarup Kumar; Prasad, Manoj

2013-01-01

The NAC proteins represent a major plant-specific transcription factor family that has established enormously diverse roles in various plant processes. Aided by the availability of complete genomes, several members of this family have been identified in Arabidopsis, rice, soybean and poplar. However, no comprehensive investigation has been presented for the recently sequenced, naturally stress tolerant crop, Setaria italica (foxtail millet) that is famed as a model crop for bioenergy research. In this study, we identified 147 putative NAC domain-encoding genes from foxtail millet by systematic sequence analysis and physically mapped them onto nine chromosomes. Genomic organization suggested that inter-chromosomal duplications may have been responsible for expansion of this gene family in foxtail millet. Phylogenetically, they were arranged into 11 distinct sub-families (I-XI), with duplicated genes fitting into one cluster and possessing conserved motif compositions. Comparative mapping with other grass species revealed some orthologous relationships and chromosomal rearrangements including duplication, inversion and deletion of genes. The evolutionary significance as duplication and divergence of NAC genes based on their amino acid substitution rates was understood. Expression profiling against various stresses and phytohormones provides novel insights into specific and/or overlapping expression patterns of SiNAC genes, which may be responsible for functional divergence among individual members in this crop. Further, we performed structure modeling and molecular simulation of a stress-responsive protein, SiNAC128, proffering an initial framework for understanding its molecular function. Taken together, this genome-wide identification and expression profiling unlocks new avenues for systematic functional analysis of novel NAC gene family candidates which may be applied for improvising stress adaption in plants. PMID:23691254

Comprehensive genome-wide survey, genomic constitution and expression profiling of the NAC transcription factor family in foxtail millet (Setaria italica L.).

PubMed

Puranik, Swati; Sahu, Pranav Pankaj; Mandal, Sambhu Nath; B, Venkata Suresh; Parida, Swarup Kumar; Prasad, Manoj

2013-01-01

The NAC proteins represent a major plant-specific transcription factor family that has established enormously diverse roles in various plant processes. Aided by the availability of complete genomes, several members of this family have been identified in Arabidopsis, rice, soybean and poplar. However, no comprehensive investigation has been presented for the recently sequenced, naturally stress tolerant crop, Setaria italica (foxtail millet) that is famed as a model crop for bioenergy research. In this study, we identified 147 putative NAC domain-encoding genes from foxtail millet by systematic sequence analysis and physically mapped them onto nine chromosomes. Genomic organization suggested that inter-chromosomal duplications may have been responsible for expansion of this gene family in foxtail millet. Phylogenetically, they were arranged into 11 distinct sub-families (I-XI), with duplicated genes fitting into one cluster and possessing conserved motif compositions. Comparative mapping with other grass species revealed some orthologous relationships and chromosomal rearrangements including duplication, inversion and deletion of genes. The evolutionary significance as duplication and divergence of NAC genes based on their amino acid substitution rates was understood. Expression profiling against various stresses and phytohormones provides novel insights into specific and/or overlapping expression patterns of SiNAC genes, which may be responsible for functional divergence among individual members in this crop. Further, we performed structure modeling and molecular simulation of a stress-responsive protein, SiNAC128, proffering an initial framework for understanding its molecular function. Taken together, this genome-wide identification and expression profiling unlocks new avenues for systematic functional analysis of novel NAC gene family candidates which may be applied for improvising stress adaption in plants.

Plant hormone signalling through the eye of the mass spectrometer.

PubMed

Walton, Alan; Stes, Elisabeth; De Smet, Ive; Goormachtig, Sofie; Gevaert, Kris

2015-03-01

Plant growth and development are regulated by hormones and the associated signalling pathways share several common steps, the first being the detection of the signal by receptor proteins. This typically leads to conformational changes in the receptor, thereby modifying its spectrum of interaction partners. Next, secondary signals are transmitted via rapid post-translational cascades, such as targeted phosphorylation or ubiquitination, resulting in the activation/deactivation, relocalization or degradation of target proteins. These events finally give rise to the signal-dependent read-out, such as changes in gene expression and regulation of protein activity. So far, the majority of studies aimed at unravelling hormone signalling pathways in plants relied on genetic or transcriptomic approaches. During the last decade however, MS-driven proteomic methods became increasingly popular tools in plant research as they reveal the specific mechanisms controlled by phytohormones, which for a large part occur on the level of the proteome. Here, we provide an up-to-date review on the growing body of work in these areas using MS-based techniques, with a focus on nonpeptide plant hormones. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Systems biology and genome-wide approaches to unveil the molecular players involved in the pre-germinative metabolism: implications on seed technology traits.

PubMed

Macovei, Anca; Pagano, Andrea; Leonetti, Paola; Carbonera, Daniela; Balestrazzi, Alma; Araújo, Susana S

2017-05-01

The pre-germinative metabolism is among the most fascinating aspects of seed biology. The early seed germination phase, or pre-germination, is characterized by rapid water uptake (imbibition), which directs a series of dynamic biochemical events. Among those are enzyme activation, DNA damage and repair, and use of reserve storage compounds, such as lipids, carbohydrates and proteins. Industrial seedling production and intensive agricultural production systems require seed stocks with high rate of synchronized germination and low dormancy. Consequently, seed dormancy, a quantitative trait related to the activation of the pre-germinative metabolism, is probably the most studied seed trait in model species and crops. Single omics, systems biology, QTLs and GWAS mapping approaches have unveiled a list of molecules and regulatory mechanisms acting at transcriptional, post-transcriptional and post-translational levels. Most of the identified candidate genes encode for regulatory proteins targeting ROS, phytohormone and primary metabolisms, corroborating the data obtained from simple molecular biology approaches. Emerging evidences show that epigenetic regulation plays a crucial role in the regulation of these mentioned processes, constituting a still unexploited strategy to modulate seed traits. The present review will provide an up-date of the current knowledge on seed pre-germinative metabolism, gathering the most relevant results from physiological, genetics, and omics studies conducted in model and crop plants. The effects exerted by the biotic and abiotic stresses and priming are also addressed. The possible implications derived from the modulation of pre-germinative metabolism will be discussed from the point of view of seed quality and technology.

Genome-wide identification and characterization of the NF-Y gene family in grape (vitis vinifera L.).

PubMed

Ren, Chong; Zhang, Zhan; Wang, Yi; Li, Shaohua; Liang, Zhenchang

2016-08-11

Nuclear factor Y (NF-Y) transcription factor is composed of three distinct subunits: NF-YA, NF-YB and NF-YC. Many members of NF-Y family have been reported to be key regulators in plant development, phytohormone signaling and drought tolerance. However, the function of the NF-Y family is less known in grape (Vitis vinifera L.). A total of 34 grape NF-Y genes that distributed unevenly on grape (V. vinifera) chromosomes were identified in this study. Phylogenetic analysis was performed to predict functional similarities between Arabidopsis thaliana and grape NF-Y genes. Comparison of the structures of grape NF-Y genes (VvNF-Ys) revealed their functional conservation and alteration. Furthermore, we investigated the expression profiles of VvNF-Ys in response to various stresses, phytohormone treatments, and in leaves and grape berries with various sugar contents at different developmental stages. The relationship between VvNF-Y transcript levels and sugar content was examined to select candidates for exogenous sugar treatments. Quantitative real-time PCR (qPCR) indicated that many VvNF-Ys responded to different sugar stimuli with variations in transcript abundance. qPCR and publicly available microarray data suggest that VvNF-Ys exhibit distinct expression patterns in different grape organs and developmental stages, and a number of VvNF-Ys may participate in responses to multiple abiotic and biotic stresses, phytohormone treatments and sugar accumulation or metabolism. In this study, we characterized 34 VvNF-Ys based on their distributions on chromosomes, gene structures, phylogenetic relationship with Arabidopsis NF-Y genes, and their expression patterns. The potential roles of VvNF-Ys in sugar accumulation or metabolism were also investigated. Altogether, the data provide significant insights on VvNF-Ys, and lay foundations for further functional studies of NF-Y genes in grape.

A Digital Tectonic Activity Map of the Earth

NASA Technical Reports Server (NTRS)

Lowman, Paul; Masuoka, Penny; Montgomery, Brian; OLeary, Jay; Salisbury, Demetra; Yates, Jacob

1999-01-01

The subject of neotectonics, covering the structures and structural activity of the last 5 million years (i.e., post-Miocene) is a well-recognized field, including "active tectonics," focussed on the last 500,000 years in a 1986 National Research Council report of that title. However, there is a cartographic gap between tectonic maps, generally showing all features regardless of age, and maps of current seismic or volcanic activity. We have compiled a map intended to bridge this gap, using modern data bases and computer-aided cartographic techniques. The maps presented here are conceptually descended from an earlier map showing tectonic and volcanic activity of the last one million years. Drawn by hand with the National Geographic Society's 1975 "The Physical World" map as a base, the 1981 map in various revisions has been widely reproduced in textbooks and various technical publications. However, two decades of progress call for a completely new map that can take advantage of new knowledge and cartographic techniques. The digital tectonic activity map (DTM), presented in shaded relief (Fig. 1) and schematic (Fig. 2) versions, is the result. The DTM is intended to show tectonism and volcanism of the last one million years, a period long enough to be representative of global activity, but short enough that features such as fault scarps and volcanos are still geomorphically recognizable. Data Sources and Cartographic Methods The DTM is based on a wide range of sources, summarized in Table 1. The most important is the digital elevation model, used to construct a shaded relief map. The bathymetry is largely from satellite altimetry, specifically the marine gravity compilations by Smith and Sandwell (1996). The shaded relief map was designed to match the new National Geographic Society world physical map (1992), although drawn independently, from the digital elevation model. The Robinson Projection is used instead of the earlier Van der Grinten one. Although neither conformal nor equal-area, the Robinson Projection provides a reasonable compromise and retains useful detail at high latitudes.

CMIS: Crime Map Information System for Safety Environment

NASA Astrophysics Data System (ADS)

Kasim, Shahreen; Hafit, Hanayanti; Yee, Ng Peng; Hashim, Rathiah; Ruslai, Husni; Jahidin, Kamaruzzaman; Syafwan Arshad, Mohammad

2016-11-01

Crime Map is an online web based geographical information system that assists the public and users to visualize crime activities geographically. It acts as a platform for the public communities to share crime activities they encountered. Crime and violence plague the communities we are living in. As part of the community, crime prevention is everyone's responsibility. The purpose of Crime Map is to provide insights of the crimes occurring around Malaysia and raise the public's awareness on crime activities in their neighbourhood. For that, Crime Map visualizes crime activities on a geographical heat maps, generated based on geospatial data. Crime Map analyse data obtained from crime reports to generate useful information on crime trends. At the end of the development, users should be able to make use of the system to access to details of crime reported, crime analysis and report crimes activities. The development of Crime Map also enable the public to obtain insights about crime activities in their area. Thus, enabling the public to work together with the law enforcer to prevent and fight crime.

Phytohormones enabled endophytic fungal symbiosis improve aluminum phytoextraction in tolerant Solanum lycopersicum: An examples of Penicillium janthinellum LK5 and comparison with exogenous GA3.

PubMed

Khan, Abdul Latif; Waqas, Muhammad; Hussain, Javid; Al-Harrasi, Ahmed; Hamayun, Muhammad; Lee, In-Jung

2015-09-15

This work investigates the potentials of fungal-endophyte Penicillium janthinellum LK5 (PjLK5) and its inherent gibberellic acid (GA3) as reference to enhance aluminum (Al) induced toxicity in tolerant tomato (Solanum lycopersicum) plants. Initial screening showed significantly higher uptake of Al by PjLK5. Aluminum stress (100 μM) significantly retarted plant growth in control plants. Conversely PjLK5 and GA3 application significantly increased morphological attributes of Al-tolerant tomato plants with or without Al-stress. PjLK5 inoculation with and without Al-stress maintained the plant growth whilst extracting and translocating higher Al in shoot (∼ 1 92 mg/kg) and root (∼ 296 mg/kg). This was almost similar in GA3 treatments as well. In addition, PjLK5 inoculation extended protective effects to tomato plants by maintaining reduced cellular superoxide anions in Al stress. Al-induced oxidative stress was further reduced due to significantly higher activity of metal-responsive reduced glutathione. The functional membrane was less damaged in PjLK5 and GA3 treatments because the plants synthesized reduced levels of malondialdhyde, lenolenic and linoleic acids. Defense-related endogenous phytohormone salicylic acid was significantly up-regulated to counteract the adverse effects of Al-stress. In conclusion, the PjLK5 possess a similar bio-prospective potential as of GA3. Application of such biochemically active endophyte could increase metal phytoextraction whilst maintaining crop physiological homeostasis. Copyright © 2015 Elsevier B.V. All rights reserved.

Increasing carbon availability stimulates growth and secondary metabolites via modulation of phytohormones in winter wheat

PubMed Central

Reichelt, Michael; Chowdhury, Somak; Hammerbacher, Almuth; Hartmann, Henrik

2017-01-01

Abstract Phytohormones play important roles in plant acclimation to changes in environmental conditions. However, their role in whole-plant regulation of growth and secondary metabolite production under increasing atmospheric CO2 concentrations ([CO2]) is uncertain but crucially important for understanding plant responses to abiotic stresses. We grew winter wheat (Triticum aestivum) under three [CO2] (170, 390, and 680 ppm) over 10 weeks, and measured gas exchange, relative growth rate (RGR), soluble sugars, secondary metabolites, and phytohormones including abscisic acid (ABA), auxin (IAA), jasmonic acid (JA), and salicylic acid (SA) at the whole-plant level. Our results show that, at the whole-plant level, RGR positively correlated with IAA but not ABA, and secondary metabolites positively correlated with JA and JA-Ile but not SA. Moreover, soluble sugars positively correlated with IAA and JA but not ABA and SA. We conclude that increasing carbon availability stimulates growth and production of secondary metabolites via up-regulation of auxin and jasmonate levels, probably in response to sugar-mediated signalling. Future low [CO2] studies should address the role of reactive oxygen species (ROS) in leaf ABA and SA biosynthesis, and at the transcriptional level should focus on biosynthetic and, in particular, on responsive genes involved in [CO2]-induced hormonal signalling pathways. PMID:28159987

Characterization of a wheat (Triticum aestivum L.) expansin gene, TaEXPB23, involved in the abiotic stress response and phytohormone regulation.

PubMed

Han, Yang yang; Li, Ai xiu; Li, Feng; Zhao, Mei rong; Wang, Wei

2012-05-01

Expansins are proteins that are generally accepted to be key regulators of cell wall extension and plant growth. We examined the expression pattern of TaEXPB23, a wheat (Triticum aestivum L.) expansin gene, under exogenous phytohormone and abiotic stress treatments. In addition, we evaluated its function in the tolerance to salt stress and high temperature (HT) by overexpressing it in transgenic tobacco plants. In subcellular localization assays, TaEXPB23 localized to the cell wall. Expression analysis demonstrated that the transcription pattern of TaEXPB23 corresponded to wheat coleoptile growth. Real-time RT-PCR analysis revealed that TaEXPB23 transcript expression was upregulated by exogenous methyl jasmonate (MeJA) and salt stress, but downregulated by exogenous gibberellins (GA₃), ethylene (ET), indole-3-acetic acid (IAA) and α-naphthlcetic acid (NAA). Overexpression of TaEXPB23 in tobacco (tabacum) conferred tolerance to salt stress by enhancing water retention ability (WRA) and decreasing osmotic potential (OP). However, transgenic plants overexpressing TaEXPB23 did not show any improvement in the tolerance to HT stress. These results suggested that TaEXPB23 is regulated by phytohormones and is involved in the regulation of salt stress tolerance. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Parasitism by Cuscuta pentagona sequentially induces JA and SA defence pathways in tomato.

PubMed

Runyon, Justin B; Mescher, Mark C; Felton, Gary W; De Moraes, Consuelo M

2010-02-01

While plant responses to herbivores and pathogens are well characterized, responses to attack by other plants remain largely unexplored. We measured phytohormones and C(18) fatty acids in tomato attacked by the parasitic plant Cuscuta pentagona, and used transgenic and mutant plants to explore the roles of the defence-related phytohormones salicylic acid (SA) and jasmonic acid (JA). Parasite attachment to 10-day-old tomato plants elicited few biochemical changes, but a second attachment 10 d later elicited a 60-fold increase in JA, a 30-fold increase in SA and a hypersensitive-like response (HLR). Host age also influenced the response: neither Cuscuta seedlings nor established vines elicited a HLR in 10-day-old hosts, but both did in 20-day-old hosts. Parasites grew larger on hosts deficient in SA (NahG) or insensitive to JA [jasmonic acid-insensitive1 (jai1)], suggesting that both phytohormones mediate effective defences. Moreover, amounts of JA peaked 12 h before SA, indicating that defences may be coordinated via sequential induction of these hormones. Parasitism also induced increases in free linolenic and linoleic acids and abscisic acid. These findings provide the first documentation of plant hormonal signalling induced by a parasitic plant and show that tomato responses to C. pentagona display characteristics similar to both herbivore- and pathogen-induced responses.

Genome-Wide Evolutionary Characterization and Expression Analyses of WRKY Family Genes in Brachypodium distachyon

PubMed Central

Wen, Feng; Zhu, Hong; Li, Peng; Jiang, Min; Mao, Wenqing; Ong, Chermaine; Chu, Zhaoqing

2014-01-01

Members of plant WRKY gene family are ancient transcription factors that function in plant growth and development and respond to biotic and abiotic stresses. In our present study, we have investigated WRKY family genes in Brachypodium distachyon, a new model plant of family Poaceae. We identified a total of 86 WRKY genes from B. distachyon and explored their chromosomal distribution and evolution, domain alignment, promoter cis-elements, and expression profiles. Combining the analysis of phylogenetic tree of BdWRKY genes and the result of expression profiling, results showed that most of clustered gene pairs had higher similarities in the WRKY domain, suggesting that they might be functionally redundant. Neighbour-joining analysis of 301 WRKY domains from Oryza sativa, Arabidopsis thaliana, and B. distachyon suggested that BdWRKY domains are evolutionarily more closely related to O. sativa WRKY domains than those of A. thaliana. Moreover, tissue-specific expression profile of BdWRKY genes and their responses to phytohormones and several biotic or abiotic stresses were analysed by quantitative real-time PCR. The results showed that the expression of BdWRKY genes was rapidly regulated by stresses and phytohormones, and there was a strong correlation between promoter cis-elements and the phytohormones-induced BdWRKY gene expression. PMID:24453041

Adaptation to altitude affects the senescence response to chilling in the perennial plant Arabis alpina

PubMed Central

Wingler, Astrid; Juvany, Marta; Cuthbert, Caroline; Munné-Bosch, Sergi

2015-01-01

In annual plants with determinate growth, sugar accumulation signals high carbon availability once growth has ceased, resulting in senescence-dependent nutrient recycling to the seeds. However, this senescence-inducing effect of sugars is abolished at cold temperature, where sugar accumulation is important for protection. Here, natural variation was exploited to analyse the effect of chilling on interactions between leaf senescence, sugars, and phytohormones in Arabis alpina, a perennial plant with indeterminate growth. Eight accessions of A. alpina originating from between 2090 and 3090 m above sea level in the French Alps were used to identify heritable adaptations in senescence, stress response, sugars, and phytohormones to altitude. Accessions from high altitudes showed an enhanced capacity for sucrose accumulation and a diminished loss of chlorophyll in response to chilling. At warm temperature, sucrose content was negatively correlated with chlorophyll content, and sucrose treatment induced leaf senescence. Chilling resulted in lower indole-3-acetic acid, but higher zeatin and jasmonic acid contents. Interactions between sugar and phytohormones included a positive correlation between sucrose and jasmonic acid contents that may be involved in promoting the stress-dependent decline in chlorophyll. These findings reveal regulatory interactions that underlie adaptation in the senescence and stress response to chilling. PMID:25371506

Unveiling the functional diversity of the Alpha-Beta hydrolase fold in plants

PubMed Central

Mindrebo, Jeffrey T.; Nartey, Charisse M.; Seto, Yoshiya; Burkart, Michael D.; Noel, Joseph P.

2017-01-01

The alpha/beta hydrolase (ABH) superfamily is a widespread and functionally malleable protein fold recognized for its diverse biochemical activities across all three domains of life. ABH enzymes possess unexpected catalytic activity in the green plant lineage through selective alterations in active site architecture and chemistry. Furthermore, the ABH fold serves as the core structure for phytohormone and ligand receptors in the gibberellin, strigolactone, and karrikin signaling pathways in plants. Despite recent discoveries, the ABH family is sparsely characterized in plants, a sessile kingdom known to evolve complex and specialized chemical adaptations as survival responses to widely varying biotic and abiotic ecologies. This review calls attention to the ABH superfamily in the plant kingdom to highlight the functional adaptability of the ABH fold. PMID:27662376

Provisional maps of thermal areas in Yellowstone National Park, based on satellite thermal infrared imaging and field observations

USGS Publications Warehouse

Vaughan, R. Greg; Heasler, Henry; Jaworowski, Cheryl; Lowenstern, Jacob B.; Keszthelyi, Laszlo P.

2014-01-01

Maps that define the current distribution of geothermally heated ground are useful toward setting a baseline for thermal activity to better detect and understand future anomalous hydrothermal and (or) volcanic activity. Monitoring changes in the dynamic thermal areas also supports decisions regarding the development of Yellowstone National Park infrastructure, preservation and protection of park resources, and ensuring visitor safety. Because of the challenges associated with field-based monitoring of a large, complex geothermal system that is spread out over a large and remote area, satellite-based thermal infrared images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) were used to map the location and spatial extent of active thermal areas, to generate thermal anomaly maps, and to quantify the radiative component of the total geothermal heat flux. ASTER thermal infrared data acquired during winter nights were used to minimize the contribution of solar heating of the surface. The ASTER thermal infrared mapping results were compared to maps of thermal areas based on field investigations and high-resolution aerial photos. Field validation of the ASTER thermal mapping is an ongoing task. The purpose of this report is to make available ASTER-based maps of Yellowstone’s thermal areas. We include an appendix containing the names and characteristics of Yellowstone’s thermal areas, georeferenced TIFF files containing ASTER thermal imagery, and several spatial data sets in Esri shapefile format.

Gibberellic Acid: A Key Phytohormone for Spikelet Fertility in Rice Grain Production.

PubMed

Kwon, Choon-Tak; Paek, Nam-Chon

2016-05-23

The phytohormone gibberellic acid (GA) has essential signaling functions in multiple processes during plant development. In the "Green Revolution", breeders developed high-yield rice cultivars that exhibited both semi-dwarfism and altered GA responses, thus improving grain production. Most studies of GA have concentrated on germination and cell elongation, but GA also has a pivotal role in floral organ development, particularly in stamen/anther formation. In rice, GA signaling plays an important role in spikelet fertility; however, the molecular genetic and biochemical mechanisms of GA in male fertility remain largely unknown. Here, we review recent progress in understanding the network of GA signaling and its connection with spikelet fertility, which is tightly associated with grain productivity in cereal crops.

Susceptibility-based functional brain mapping by 3D deconvolution of an MR-phase activation map.

PubMed

Chen, Zikuan; Liu, Jingyu; Calhoun, Vince D

2013-05-30

The underlying source of T2*-weighted magnetic resonance imaging (T2*MRI) for brain imaging is magnetic susceptibility (denoted by χ). T2*MRI outputs a complex-valued MR image consisting of magnitude and phase information. Recent research has shown that both the magnitude and the phase images are morphologically different from the source χ, primarily due to 3D convolution, and that the source χ can be reconstructed from complex MR images by computed inverse MRI (CIMRI). Thus, we can obtain a 4D χ dataset from a complex 4D MR dataset acquired from a brain functional MRI study by repeating CIMRI to reconstruct 3D χ volumes at each timepoint. Because the reconstructed χ is a more direct representation of neuronal activity than the MR image, we propose a method for χ-based functional brain mapping, which is numerically characterised by a temporal correlation map of χ responses to a stimulant task. Under the linear imaging conditions used for T2*MRI, we show that the χ activation map can be calculated from the MR phase map by CIMRI. We validate our approach using numerical simulations and Gd-phantom experiments. We also analyse real data from a finger-tapping visuomotor experiment and show that the χ-based functional mapping provides additional activation details (in the form of positive and negative correlation patterns) beyond those generated by conventional MR-magnitude-based mapping. Copyright © 2013 Elsevier B.V. All rights reserved.

Isolation, structural analysis, and expression characteristics of the maize (Zea mays L.) hexokinase gene family.

PubMed

Zhang, Zhongbao; Zhang, Jiewei; Chen, Yajuan; Li, Ruifen; Wang, Hongzhi; Ding, Liping; Wei, Jianhua

2014-09-01

Hexokinases (HXKs, EC 2.7.1.1) play important roles in metabolism, glucose (Glc) signaling, and phosphorylation of Glc and fructose and are ubiquitous in all organisms. Despite their physiological importance, the maize HXK (ZmHXK) genes have not been analyzed systematically. We isolated and characterized nine members of the ZmHXK gene family which were distributed on 3 of the 10 maize chromosomes. A multiple sequence alignment and motif analysis revealed that the maize ZmHXK proteins share three conserved domains. Phylogenetic analysis revealed that the ZmHXK family can be divided into four subfamilies. We identified putative cis-elements in the ZmHXK promoter sequences potentially involved in phytohormone and abiotic stress responses, sugar repression, light and circadian rhythm regulation, Ca(2+) responses, seed development and germination, and CO2-responsive transcriptional activation. To study the functions of maize HXK isoforms, we characterized the expression of the ZmHXK5 and ZmHXK6 genes, which are evolutionarily related to the OsHXK5 and OsHXK6 genes from rice. Analysis of tissue-specific expression patterns using quantitative real time-PCR showed that ZmHXK5 was highly expressed in tassels, while ZmHXK6 was expressed in both tassels and leaves. ZmHXK5 and ZmHXK6 expression levels were upregulated by phytohormones and by abiotic stress.

Role of the phytochrome and cryptochrome signaling pathways in hypocotyl phototropism.

PubMed

Tsuchida-Mayama, Tomoko; Sakai, Tatsuya; Hanada, Atsushi; Uehara, Yukiko; Asami, Tadao; Yamaguchi, Shinjiro

2010-05-01

Unilateral blue-light irradiation activates phototropin (phot) photoreceptors, resulting in asymmetric distribution of the phytohormone auxin and induction of a phototropic response in higher plants. Other photoreceptors, including phytochrome (phy) and cryptochrome (cry), have been proposed as modulators of phototropic responses. We show here that either phy or cry is required for hypocotyl phototropism in Arabidopsis thaliana under high fluence rates of blue light, and that constitutive expression of ROOT PHOTOTROPISM 2 (RPT2) and treatment with the phytohormone gibberellin (GA) biosynthesis inhibitor paclobutrazol partially and independently complement the non-phototropic hypocotyl phenotype of the phyA cry1 cry2 mutant under high fluence rates of blue light. Our results indicate that induction of RPT2 and reduction in the GA are crucial for hypocotyl phototropic regulation by phy and cry. We also show that GA suppresses hypocotyl bending via destabilization of DELLA transcriptional regulators under darkness, but does not suppress the phototropic response in the presence of either phyA or cryptochromes, suggesting that these photoreceptors control not only the GA content but also the GA sensing and/or signaling that affects hypocotyl phototropism. The metabolic and signaling regulation of not only auxin but also GA by photoreceptors therefore appears to determine the hypocotyl growth pattern, including phototropic and gravitropic responses and inhibition of hypocotyl elongation, for adaptation to various light environments.

Exposure to Sound Vibrations Lead to Transcriptomic, Proteomic and Hormonal Changes in Arabidopsis

PubMed Central

Ghosh, Ritesh; Mishra, Ratnesh Chandra; Choi, Bosung; Kwon, Young Sang; Bae, Dong Won; Park, Soo-Chul; Jeong, Mi-Jeong; Bae, Hanhong

2016-01-01

Sound vibration (SV) is considered as an external mechanical force that modulates plant growth and development like other mechanical stimuli (e.g., wind, rain, touch and vibration). A number of previous and recent studies reported developmental responses in plants tailored against SV of varied frequencies. This strongly suggests the existence of sophisticated molecular mechanisms for SV perception and signal transduction. Despite this there exists a huge gap in our understanding regarding the SV-mediated molecular alterations, which is a prerequisite to gain insight into SV-mediated plant development. Herein, we investigated the global gene expression changes in Arabidopsis thaliana upon treatment with five different single frequencies of SV at constant amplitude for 1 h. As a next step, we also studied the SV-mediated proteomic changes in Arabidopsis. Data suggested that like other stimuli, SV also activated signature cellular events, for example, scavenging of reactive oxygen species (ROS), alteration of primary metabolism, and hormonal signaling. Phytohormonal analysis indicated that SV-mediated responses were, in part, modulated by specific alterations in phytohormone levels; especially salicylic acid (SA). Notably, several touch regulated genes were also up-regulated by SV treatment suggesting a possible molecular crosstalk among the two mechanical stimuli, sound and touch. Overall, these results provide a molecular basis to SV triggered global transcriptomic, proteomic and hormonal changes in plant. PMID:27665921

A thaumatin-like protein of Ocimum basilicum confers tolerance to fungal pathogen and abiotic stress in transgenic Arabidopsis

PubMed Central

Misra, Rajesh Chandra; Sandeep; Kamthan, Mohan; Kumar, Santosh; Ghosh, Sumit

2016-01-01

Plant often responds to fungal pathogens by expressing a group of proteins known as pathogenesis-related proteins (PRs). The expression of PR is mediated through pathogen-induced signal-transduction pathways that are fine-tuned by phytohormones such as methyl jasmonate (MeJA). Here, we report functional characterization of an Ocimum basilicum PR5 family member (ObTLP1) that was identified from a MeJA-responsive expression sequence tag collection. ObTLP1 encodes a 226 amino acid polypeptide that showed sequence and structural similarities with a sweet-tasting protein thaumatin of Thaumatococcus danielli and also with a stress-responsive protein osmotin of Nicotiana tabacum. The expression of ObTLP1 in O. basilicum was found to be organ-preferential under unstressed condition, and responsive to biotic and abiotic stresses, and multiple phytohormone elicitations. Bacterially-expressed recombinant ObTLP1 inhibited mycelial growth of the phytopathogenic fungi, Scleretonia sclerotiorum and Botrytis cinerea; thereby, suggesting its antifungal activity. Ectopic expression of ObTLP1 in Arabidopsis led to enhanced tolerance to S. sclerotiorum and B. cinerea infections, and also to dehydration and salt stress. Moreover, induced expression of the defense marker genes suggested up-regulation of the defense-response pathways in ObTLP1-expressing Arabidopsis upon fungal challenge. Thus, ObTLP1 might be useful for providing tolerance to the fungal pathogens and abiotic stresses in crops. PMID:27150014

A thaumatin-like protein of Ocimum basilicum confers tolerance to fungal pathogen and abiotic stress in transgenic Arabidopsis.

PubMed

Misra, Rajesh Chandra; Sandeep; Kamthan, Mohan; Kumar, Santosh; Ghosh, Sumit

2016-05-06

Plant often responds to fungal pathogens by expressing a group of proteins known as pathogenesis-related proteins (PRs). The expression of PR is mediated through pathogen-induced signal-transduction pathways that are fine-tuned by phytohormones such as methyl jasmonate (MeJA). Here, we report functional characterization of an Ocimum basilicum PR5 family member (ObTLP1) that was identified from a MeJA-responsive expression sequence tag collection. ObTLP1 encodes a 226 amino acid polypeptide that showed sequence and structural similarities with a sweet-tasting protein thaumatin of Thaumatococcus danielli and also with a stress-responsive protein osmotin of Nicotiana tabacum. The expression of ObTLP1 in O. basilicum was found to be organ-preferential under unstressed condition, and responsive to biotic and abiotic stresses, and multiple phytohormone elicitations. Bacterially-expressed recombinant ObTLP1 inhibited mycelial growth of the phytopathogenic fungi, Scleretonia sclerotiorum and Botrytis cinerea; thereby, suggesting its antifungal activity. Ectopic expression of ObTLP1 in Arabidopsis led to enhanced tolerance to S. sclerotiorum and B. cinerea infections, and also to dehydration and salt stress. Moreover, induced expression of the defense marker genes suggested up-regulation of the defense-response pathways in ObTLP1-expressing Arabidopsis upon fungal challenge. Thus, ObTLP1 might be useful for providing tolerance to the fungal pathogens and abiotic stresses in crops.

Cryptochrome 1 regulates growth and development in Brassica through alteration in the expression of genes involved in light, phytohormone and stress signalling.

PubMed

Sharma, Pooja; Chatterjee, Mithu; Burman, Naini; Khurana, Jitendra P

2014-04-01

The blue light photoreceptors cryptochromes are ubiquitous in higher plants and are vital for regulating plant growth and development. In spite of being involved in controlling agronomically important traits like plant height and flowering time, cryptochromes have not been extensively characterized from agriculturally important crops. Here we show that overexpression of CRY1 from Brassica napus (BnCRY1), an oilseed crop, results in short-statured Brassica transgenics, likely to be less prone to wind and water lodging. The overexpression of BnCRY1 accentuates the inhibition of cell elongation in hypocotyls of transgenic seedlings. The analysis of hypocotyl growth inhibition and anthocyanin accumulation responses in BnCRY1 overexpressors substantiates that regulation of seedling photomorphogenesis by cry1 is dependent on light intensity. This study highlights that the photoactivated cry1 acts through coordinated induction and suppression of specific downstream genes involved in phytohormone synthesis or signalling, and those involved in cell wall modification, during de-etiolation of Brassica seedlings. The microarray-based transcriptome profiling also suggests that the overexpression of BnCRY1 alters abiotic/biotic stress signalling pathways; the transgenic seedlings were apparently oversensitive to abscisic acid (ABA) and mannitol. © 2013 John Wiley & Sons Ltd.

The role of photogeologic mapping in traverse planning: Lessons from DRATS 2010 activities

USGS Publications Warehouse

Skinner, James A.; Fortezzo, Corey M.

2013-01-01

We produced a 1:24,000 scale photogeologic map of the Desert Research and Technology Studies (DRATS) 2010 simulated lunar mission traverse area and surrounding environments located within the northeastern part of the San Francisco Volcanic Field (SFVF), north-central Arizona. To mimic an exploratory mission, we approached the region “blindly” by rejecting prior knowledge or preconceived notions of the regional geologic setting and focused instead only on image and topographic base maps that were intended to be equivalent to pre-cursor mission “orbital returns”. We used photogeologic mapping techniques equivalent to those employed during the construction of modern planetary geologic maps. Based on image and topographic base maps, we identified 4 surficial units (talus, channel, dissected, and plains units), 5 volcanic units (older cone, younger cone, older flow, younger flow, and block field units), and 5 basement units (grey-toned mottled, red-toned platy, red-toned layered, light-toned slabby, and light-toned layered units). Comparison of our remote-based map units with published field-based map units indicates that the two techniques yield pervasively similar results of contrasting detail, with higher accuracies linked to remote-based units that have high topographic relief and tonal contrast relative to adjacent units. We list key scientific questions that remained after photogeologic mapping and prior to DRATS activities and identify 13 specific observations that the crew and science team would need to make in order to address those questions and refine the interpreted geologic context. We translated potential observations into 62 recommended sites for visitation and observation during the mission traverse. The production and use of a mission-specific photogeologic map for DRATS 2010 activities resulted in strategic and tactical recommendations regarding observational context and hypothesis tracking over the course of an exploratory mission.

Mixture model based joint-MAP reconstruction of attenuation and activity maps in TOF-PET

NASA Astrophysics Data System (ADS)

Hemmati, H.; Kamali-Asl, A.; Ghafarian, P.; Ay, M. R.

2018-06-01

A challenge to have quantitative positron emission tomography (PET) images is to provide an accurate and patient-specific photon attenuation correction. In PET/MR scanners, the nature of MR signals and hardware limitations have led to a real challenge on the attenuation map extraction. Except for a constant factor, the activity and attenuation maps from emission data on TOF-PET system can be determined by the maximum likelihood reconstruction of attenuation and activity approach (MLAA) from emission data. The aim of the present study is to constrain the joint estimations of activity and attenuation approach for PET system using a mixture model prior based on the attenuation map histogram. This novel prior enforces non-negativity and its hyperparameters can be estimated using a mixture decomposition step from the current estimation of the attenuation map. The proposed method can also be helpful on the solving of scaling problem and is capable to assign the predefined regional attenuation coefficients with some degree of confidence to the attenuation map similar to segmentation-based attenuation correction approaches. The performance of the algorithm is studied with numerical and Monte Carlo simulations and a phantom experiment and was compared with MLAA algorithm with and without the smoothing prior. The results demonstrate that the proposed algorithm is capable of producing the cross-talk free activity and attenuation images from emission data. The proposed approach has potential to be a practical and competitive method for joint reconstruction of activity and attenuation maps from emission data on PET/MR and can be integrated on the other methods.

Plant stem cells in cosmetics: current trends and future directions

PubMed Central

Trehan, Sonia; Michniak-Kohn, Bozena; Beri, Kavita

2017-01-01

Plant regeneration at the cellular and tissue level is a unique process. Similar to animals, the stem cells in plants have properties that help stimulate and regenerate plants after injury. The unique properties of plant stem cells have been a recent area of interest and focus both in developing new cosmetics and studying how these extracts/phytohormones will influence animal skin. This special report focuses on the current evidence-based trends in plant stem cell-based cosmetics and sheds light on the challenges that we need to overcome in order to see meaningful changes in human skin using topical cosmetics derived from plant stem cells. PMID:29134115

Purple Phototrophic Bacterium Enhances Stevioside Yield by Stevia rebaudiana Bertoni via Foliar Spray and Rhizosphere Irrigation

PubMed Central

Wu, Jing; Wang, Yiming; Lin, Xiangui

2013-01-01

This study was conducted to compare the effects of foliar spray and rhizosphere irrigation with purple phototrophic bacteria (PPB) on growth and stevioside (ST) yield of Stevia. rebaudiana. The S. rebaudiana plants were treated by foliar spray, rhizosphere irrigation, and spray plus irrigation with PPB for 10 days, respectively. All treatments enhanced growth of S. rebaudiana, and the foliar method was more efficient than irrigation. Spraying combined with irrigation increased the ST yield plant -1 by 69.2% as compared to the control. The soil dehydrogenase activity, S. rebaudiana shoot biomass, chlorophyll content in new leaves, and soluble sugar in old leaves were affected significantly by S+I treatment, too. The PPB probably works in the rhizosphere by activating the metabolic activity of soil bacteria, and on leaves by excreting phytohormones or enhancing the activity of phyllosphere microorganisms. PMID:23825677

Unveiling the functional diversity of the alpha/beta hydrolase superfamily in the plant kingdom.

PubMed

Mindrebo, Jeffrey T; Nartey, Charisse M; Seto, Yoshiya; Burkart, Michael D; Noel, Joseph P

2016-12-01

The alpha/beta hydrolase (ABH) superfamily is a widespread and functionally malleable protein fold recognized for its diverse biochemical activities across all three domains of life. ABH enzymes possess unexpected catalytic activity in the green plant lineage through selective alterations in active site architecture and chemistry. Furthermore, the ABH fold serves as the core structure for phytohormone and ligand receptors in the gibberellin, strigolactone, and karrikin signaling pathways in plants. Despite recent discoveries, the ABH family is sparsely characterized in plants, a sessile kingdom known to evolve complex and specialized chemical adaptations as survival responses to widely varying biotic and abiotic ecologies. This review calls attention to the ABH superfamily in the plant kingdom to highlight the functional adaptability of the ABH fold. Copyright © 2016. Published by Elsevier Ltd.

Isolation and characterization of a glyphosate-degrading rhizosphere strain, Enterobacter cloacae K7.

PubMed

Kryuchkova, Yelena V; Burygin, Gennady L; Gogoleva, Natalia E; Gogolev, Yuri V; Chernyshova, Marina P; Makarov, Oleg E; Fedorov, Evgenii E; Turkovskaya, Olga V

2014-01-20

Plant-growth-promoting rhizobacteria exert beneficial effects on plants through their capacity for nitrogen fixation, phytohormone production, phosphate solubilization, and improvement of the water and mineral status of plants. We suggested that these bacteria may also have the potential to express degradative activity toward glyphosate, a commonly used organophosphorus herbicide. In this study, 10 strains resistant to a 10 mM concentration of glyphosate were isolated from the rhizoplane of various plants. Five of these strains--Alcaligenes sp. K1, Comamonas sp. K4, Azomonas sp. K5, Pseudomonas sp. K3, and Enterobacter cloacae K7--possessed a number of associative traits, including fixation of atmospheric nitrogen, solubilization of phosphates, and synthesis of the phytohormone indole-3-acetic acid. One strain, E. cloacae K7, could utilize glyphosate as a source of P. Gas-liquid chromatography showed that E. cloacae growth correlated with a decline in herbicide content in the culture medium (40% of the initial 5mM content), with no glyphosate accumulating inside the cells. Thin-layer chromatography analysis of the intermediate metabolites of glyphosate degradation found that E. cloacae K7 had a C-P lyase activity and degraded glyphosate to give sarcosine, which was then oxidized to glycine. In addition, strain K7 colonized the roots of common sunflower (Helianthus annuus L.) and sugar sorghum (Sorghum saccharatum Pers.), promoting the growth and development of sunflower seedlings. Our findings extend current knowledge of glyphosate-degrading rhizosphere bacteria and may be useful for developing a biotechnology for the cleanup and restoration of glyphosate-polluted soils. Copyright © 2013 Elsevier GmbH. All rights reserved.

Involvement of salicylic acid, ethylene and jasmonic acid signalling pathways in the susceptibility of tomato to Fusarium oxysporum.

PubMed

Di, Xiaotang; Gomila, Jo; Takken, Frank L W

2017-09-01

Phytohormones, such as salicylic acid (SA), ethylene (ET) and jasmonic acid (JA), play key roles in plant defence following pathogen attack. The involvement of these hormones in susceptibility following Fusarium oxysporum (Fo) infection has mostly been studied in Arabidopsis thaliana. However, Fo causes vascular wilt disease in a broad range of crops, including tomato (Solanum lycopersicum). Surprisingly little is known about the involvement of these phytohormones in the susceptibility of tomato towards Fo f. sp. lycopersici (Fol). Here, we investigate their involvement by the analysis of the expression of ET, JA and SA marker genes following Fol infection, and by bioassays of tomato mutants affected in either hormone production or perception. Fol inoculation triggered the expression of SA and ET marker genes, showing the activation of these pathways. NahG tomato, in which SA is degraded, became hypersusceptible to Fol infection and showed stronger disease symptoms than wild-type. In contrast, ACD and Never ripe (Nr) mutants, in which ET biosynthesis and perception, respectively, are impaired, showed decreased disease symptoms and reduced fungal colonization on infection. The susceptibility of the def1 tomato mutant, and a prosystemin over-expressing line, in which JA signalling is compromised or constitutively activated, respectively, was unaltered. Our results show that SA is a negative and ET a positive regulator of Fol susceptibility. The SA and ET signalling pathways appear to act synergistically, as an intact ET pathway is required for the induction of an SA marker gene, and vice versa. © 2017 THE AUTHORS. MOLECULAR PLANT PATHOLOGY PUBLISHED BY BRITISH SOCIETY FOR PLANT PATHOLOGY AND JOHN WILEY & SONS LTD.

Genetic regulation of maize flower development and sex determination.

PubMed

Li, Qinglin; Liu, Baoshen

2017-01-01

The determining process of pistil fate are central to maize sex determination, mainly regulated by a genetic network in which the sex-determining genes SILKLESS 1 , TASSEL SEED 1 , TASSEL SEED 2 and the paramutagenic locus Required to maintain repression 6 play pivotal roles. Maize silks, which emerge from the ear shoot and derived from the pistil, are the functional stigmas of female flowers and play a pivotal role in pollination. Previous studies on sex-related mutants have revealed that sex-determining genes and phytohormones play an important role in the regulation of flower organogenesis. The processes determining pistil fate are central to flower development, where a silk identified gene SILKLESS 1 (SK1) is required to protect pistil primordia from a cell death signal produced by two commonly known genes, TASSEL SEED 1 (TS1) and TASSEL SEED 2 (TS2). In this review, maize flower developmental process is presented together with a focus on important sex-determining mutants and hormonal signaling affecting pistil development. The role of sex-determining genes, microRNAs, phytohormones, and the paramutagenic locus Required to maintain repression 6 (Rmr6), in forming a regulatory network that determines pistil fate, is discussed. Cloning SK1 and clarifying its function were crucial in understanding the regulation network of sex determination. The signaling mechanisms of phytohormones in sex determination are also an important research focus.

Increasing carbon availability stimulates growth and secondary metabolites via modulation of phytohormones in winter wheat.

PubMed

Huang, Jianbei; Reichelt, Michael; Chowdhury, Somak; Hammerbacher, Almuth; Hartmann, Henrik

2017-02-01

Phytohormones play important roles in plant acclimation to changes in environmental conditions. However, their role in whole-plant regulation of growth and secondary metabolite production under increasing atmospheric CO2 concentrations ([CO2]) is uncertain but crucially important for understanding plant responses to abiotic stresses. We grew winter wheat (Triticum aestivum) under three [CO2] (170, 390, and 680 ppm) over 10 weeks, and measured gas exchange, relative growth rate (RGR), soluble sugars, secondary metabolites, and phytohormones including abscisic acid (ABA), auxin (IAA), jasmonic acid (JA), and salicylic acid (SA) at the whole-plant level. Our results show that, at the whole-plant level, RGR positively correlated with IAA but not ABA, and secondary metabolites positively correlated with JA and JA-Ile but not SA. Moreover, soluble sugars positively correlated with IAA and JA but not ABA and SA. We conclude that increasing carbon availability stimulates growth and production of secondary metabolites via up-regulation of auxin and jasmonate levels, probably in response to sugar-mediated signalling. Future low [CO2] studies should address the role of reactive oxygen species (ROS) in leaf ABA and SA biosynthesis, and at the transcriptional level should focus on biosynthetic and, in particular, on responsive genes involved in [CO2]-induced hormonal signalling pathways. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Effect of Hypergravity and Phytohormones on Isoflavonoid Accumulation in Soybean ( Glycine max. L.) Callus

NASA Astrophysics Data System (ADS)

Downey, Peter J.; Levine, Lanfang H.; Musgrave, Mary E.; McKeon-Bennett, Michelle; Moane, Siobhán

2013-02-01

The objective of this study was to explore the potential interaction between gravity and growth hormones on isoflavonoid accumulation. Soybean callus ( Glycine max (L.) Merr. cv. `Acme') was grown in the dark for 16 days at 22 °C in a growth medium supplemented with four different combinations of phytohormones and subjected to 4- g and 8- g forces simulated in a centrifuge and 1- g in an adjacent stationary control. Isoflavonoid aglycones and their glycoside concentrations (daidzein, genistein, daidzin, 6″-O-malonyl-7-O-glucosyl daidzein, genistin, 6″-O-malonyl-7-O-glucosyl genistein) were determined in the resulting tissues. Although gravity had no significant impact on callus growth, increasing gravity reduced isoflavonoid accumulation in three out of the four phytohormone-supplemented culture media. The ratio of the auxin naphthalene acetic acid (NAA) to the cytokinin benzylaminopurine (BAP) was found to have profound effect on both callus growth and isoflavonoid accumulation. The cytokinin BAP promoted callus tissue growth, but reduced callus isoflavonoid suggesting the isoflavonoid accumulation was not keeping pace with the cell growth in the elevated concentration of BAP. On the other hand, NAA had little or no effect on callus growth, but greatly enhanced isoflavonoid accumulation. Interactive effects of gravity and hormone on isoflavonoid accumulation were evident and its implication to the mechanism by which gravity exerts the effect on plant secondary metabolites is discussed.

Genome-wide evolutionary characterization and expression analyses of WRKY family genes in Brachypodium distachyon.

PubMed

Wen, Feng; Zhu, Hong; Li, Peng; Jiang, Min; Mao, Wenqing; Ong, Chermaine; Chu, Zhaoqing

2014-06-01

Members of plant WRKY gene family are ancient transcription factors that function in plant growth and development and respond to biotic and abiotic stresses. In our present study, we have investigated WRKY family genes in Brachypodium distachyon, a new model plant of family Poaceae. We identified a total of 86 WRKY genes from B. distachyon and explored their chromosomal distribution and evolution, domain alignment, promoter cis-elements, and expression profiles. Combining the analysis of phylogenetic tree of BdWRKY genes and the result of expression profiling, results showed that most of clustered gene pairs had higher similarities in the WRKY domain, suggesting that they might be functionally redundant. Neighbour-joining analysis of 301 WRKY domains from Oryza sativa, Arabidopsis thaliana, and B. distachyon suggested that BdWRKY domains are evolutionarily more closely related to O. sativa WRKY domains than those of A. thaliana. Moreover, tissue-specific expression profile of BdWRKY genes and their responses to phytohormones and several biotic or abiotic stresses were analysed by quantitative real-time PCR. The results showed that the expression of BdWRKY genes was rapidly regulated by stresses and phytohormones, and there was a strong correlation between promoter cis-elements and the phytohormones-induced BdWRKY gene expression. © The Author 2014. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

Chilling Affects Phytohormone and Post-Embryonic Development Pathways during Bud Break and Fruit Set in Apple (Malus domestica Borkh.)

PubMed Central

Kumar, Gulshan; Gupta, Khushboo; Pathania, Shivalika; Swarnkar, Mohit Kumar; Rattan, Usha Kumari; Singh, Gagandeep; Sharma, Ram Kumar; Singh, Anil Kumar

2017-01-01

The availability of sufficient chilling during bud dormancy plays an important role in the subsequent yield and quality of apple fruit, whereas, insufficient chilling availability negatively impacts the apple production. The transcriptome profiling during bud dormancy release and initial fruit set under low and high chill conditions was performed using RNA-seq. The comparative high number of differentially expressed genes during bud break and fruit set under high chill condition indicates that chilling availability was associated with transcriptional reorganization. The comparative analysis reveals the differential expression of genes involved in phytohormone metabolism, particularly for Abscisic acid, gibberellic acid, ethylene, auxin and cytokinin. The expression of Dormancy Associated MADS-box, Flowering Locus C-like, Flowering Locus T-like and Terminal Flower 1-like genes was found to be modulated under differential chilling. The co-expression network analysis indentified two high chill specific modules that were found to be enriched for “post-embryonic development” GO terms. The network analysis also identified hub genes including Early flowering 7, RAF10, ZEP4 and F-box, which may be involved in regulating chilling-mediated dormancy release and fruit set. The results of transcriptome and co-expression network analysis indicate that chilling availability majorly regulates phytohormone-related pathways and post-embryonic development during bud break. PMID:28198417

Investigation on Hot Workability of Homogenized Al-Zn-Mg-Cu Alloy Based on Activation Energy and Processing Map

NASA Astrophysics Data System (ADS)

Peng, Xiaoyan; Su, Wusen; Xiao, Dan; Xu, Guofu

2018-06-01

Hot deformation behaviors of the homogenized Al-Zn-Mg-Cu alloy were studied by uniaxial compression tests carried out at 623-743 K and strain rates of 0.01-10 s-1. The constitutive equation was developed for the activation energy, and thus the activation energy map was constructed. During the hot deformation, the dominated softening mechanisms were the dynamic recovery and dynamic recrystallization, which were most likely to be driven with increasing temperature and decreasing activation energy. Based on the superposition of the activation energy map and the processing map, together with the microstructure characteristics, the optimized hot workability of the alloy was proposed at the domain (670-743 K and 0.01-0.16 s-1), where the peak efficiency was 0.39 and the activation energy range was 196-260 kJ mol-1.

Re-Dimensional Thinking in Earth Science: From 3-D Virtual Reality Panoramas to 2-D Contour Maps

ERIC Educational Resources Information Center

Park, John; Carter, Glenda; Butler, Susan; Slykhuis, David; Reid-Griffin, Angelia

2008-01-01

This study examines the relationship of gender and spatial perception on student interactivity with contour maps and non-immersive virtual reality. Eighteen eighth-grade students elected to participate in a six-week activity-based course called "3-D GeoMapping." The course included nine days of activities related to topographic mapping.…

Auxin-BR Interaction Regulates Plant Growth and Development

PubMed Central

Tian, Huiyu; Lv, Bingsheng; Ding, Tingting; Bai, Mingyi; Ding, Zhaojun

2018-01-01

Plants develop a high flexibility to alter growth, development, and metabolism to adapt to the ever-changing environments. Multiple signaling pathways are involved in these processes and the molecular pathways to transduce various developmental signals are not linear but are interconnected by a complex network and even feedback mutually to achieve the final outcome. This review will focus on two important plant hormones, auxin and brassinosteroid (BR), based on the most recent progresses about these two hormone regulated plant growth and development in Arabidopsis, and highlight the cross-talks between these two phytohormones. PMID:29403511

Spatio-temporal dynamics in global rice gene expression (Oryza sativa L.) in response to high ammonium stress.

PubMed

Sun, Li; Di, Dongwei; Li, Guangjie; Kronzucker, Herbert J; Shi, Weiming

2017-05-01

Ammonium (NH 4 + ) is the predominant nitrogen (N) source in many natural and agricultural ecosystems, including flooded rice fields. While rice is known as an NH 4 + -tolerant species, it nevertheless suffers NH 4 + toxicity at elevated soil concentrations. NH 4 + excess rapidly leads to the disturbance of various physiological processes that ultimately inhibit shoot and root growth. However, the global transcriptomic response to NH 4 + stress in rice has not been examined. In this study, we mapped the spatio-temporal specificity of gene expression profiles in rice under excess NH 4 + and the changes in gene expression in root and shoot at various time points by RNA-Seq (Quantification) using Illumina HiSeqTM 2000. By comparative analysis, 307 and 675 genes were found to be up-regulated after 4h and 12h of NH 4 + exposure in the root, respectively. In the shoot, 167 genes were up-regulated at 4h, compared with 320 at 12h. According to KEGG analysis, up-regulated DEGs mainly participate in phenylpropanoid (such as flavonoid) and amino acid (such as proline, cysteine, and methionine) metabolism, which is believed to improve NH 4 + stress tolerance through adjustment of energy metabolism in the shoot, while defense and signaling pathways, guiding whole-plant acclimation, play the leading role in the root. We furthermore critically assessed the roles of key phytohormones, and found abscisic acid (ABA) and ethylene (ET) to be the major regulatory molecules responding to excess NH 4 + and activating the MAPK (mitogen-activated protein kinase) signal-transduction pathway. Moreover, we found up-regulated hormone-associated genes are involved in regulating flavonoid biosynthesis and are regulated by tissue flavonoid accumulation. Copyright © 2017 Elsevier GmbH. All rights reserved.

A Robust Crowdsourcing-Based Indoor Localization System.

PubMed

Zhou, Baoding; Li, Qingquan; Mao, Qingzhou; Tu, Wei

2017-04-14

WiFi fingerprinting-based indoor localization has been widely used due to its simplicity and can be implemented on the smartphones. The major drawback of WiFi fingerprinting is that the radio map construction is very labor-intensive and time-consuming. Another drawback of WiFi fingerprinting is the Received Signal Strength (RSS) variance problem, caused by environmental changes and device diversity. RSS variance severely degrades the localization accuracy. In this paper, we propose a robust crowdsourcing-based indoor localization system (RCILS). RCILS can automatically construct the radio map using crowdsourcing data collected by smartphones. RCILS abstracts the indoor map as the semantics graph in which the edges are the possible user paths and the vertexes are the location where users may take special activities. RCILS extracts the activity sequence contained in the trajectories by activity detection and pedestrian dead-reckoning. Based on the semantics graph and activity sequence, crowdsourcing trajectories can be located and a radio map is constructed based on the localization results. For the RSS variance problem, RCILS uses the trajectory fingerprint model for indoor localization. During online localization, RCILS obtains an RSS sequence and realizes localization by matching the RSS sequence with the radio map. To evaluate RCILS, we apply RCILS in an office building. Experiment results demonstrate the efficiency and robustness of RCILS.

A Robust Crowdsourcing-Based Indoor Localization System

PubMed Central

Zhou, Baoding; Li, Qingquan; Mao, Qingzhou; Tu, Wei

2017-01-01

WiFi fingerprinting-based indoor localization has been widely used due to its simplicity and can be implemented on the smartphones. The major drawback of WiFi fingerprinting is that the radio map construction is very labor-intensive and time-consuming. Another drawback of WiFi fingerprinting is the Received Signal Strength (RSS) variance problem, caused by environmental changes and device diversity. RSS variance severely degrades the localization accuracy. In this paper, we propose a robust crowdsourcing-based indoor localization system (RCILS). RCILS can automatically construct the radio map using crowdsourcing data collected by smartphones. RCILS abstracts the indoor map as the semantics graph in which the edges are the possible user paths and the vertexes are the location where users may take special activities. RCILS extracts the activity sequence contained in the trajectories by activity detection and pedestrian dead-reckoning. Based on the semantics graph and activity sequence, crowdsourcing trajectories can be located and a radio map is constructed based on the localization results. For the RSS variance problem, RCILS uses the trajectory fingerprint model for indoor localization. During online localization, RCILS obtains an RSS sequence and realizes localization by matching the RSS sequence with the radio map. To evaluate RCILS, we apply RCILS in an office building. Experiment results demonstrate the efficiency and robustness of RCILS. PMID:28420108

Land User and Land Cover Maps of Europe: a Webgis Platform

NASA Astrophysics Data System (ADS)

Brovelli, M. A.; Fahl, F. C.; Minghini, M.; Molinari, M. E.

2016-06-01

This paper presents the methods and implementation processes of a WebGIS platform designed to publish the available land use and land cover maps of Europe at continental scale. The system is built completely on open source infrastructure and open standards. The proposed architecture is based on a server-client model having GeoServer as the map server, Leaflet as the client-side mapping library and the Bootstrap framework at the core of the front-end user interface. The web user interface is designed to have typical features of a desktop GIS (e.g. activate/deactivate layers and order layers by drag and drop actions) and to show specific information on the activated layers (e.g. legend and simplified metadata). Users have the possibility to change the base map from a given list of map providers (e.g. OpenStreetMap and Microsoft Bing) and to control the opacity of each layer to facilitate the comparison with both other land cover layers and the underlying base map. In addition, users can add to the platform any custom layer available through a Web Map Service (WMS) and activate the visualization of photos from popular photo sharing services. This last functionality is provided in order to have a visual assessment of the available land coverages based on other user-generated contents available on the Internet. It is supposed to be a first step towards a calibration/validation service that will be made available in the future.

Silencing GhNDR1 and GhMKK2 compromised cotton resistance to Verticillium wilt

PubMed Central

Gao, Xiquan; Wheeler, Terry; Li, Zhaohu; Kenerley, Charles M.; He, Ping; Shan, Libo

2011-01-01

SUMMARY Cotton is an important cash crop worldwide and serves as a significant source of fiber, feed, foodstuff, oil and biofuel products. Considerable effort in genetics and genomics has been expended to increase sustainable yield and quality through molecular breeding and genetic engineering of new cotton cultivars. With the effort of whole genome sequencing of cotton, it is essential to develop molecular tools and resources for large-scale analysis of gene functions at the genome-wide level. We have successfully established an Agrobacterium-mediated virus-induced gene silencing (VIGS) assay in several cotton cultivars with different genetic backgrounds. The genes of interest were potently and readily silenced within 2 weeks after inoculation at the seedling stage. Importantly, we showed that silencing GhNDR1 and GhMKK2 compromised cotton resistance to the infection by Verticillium dahliae, a fungal pathogen causing Verticillium wilt. Furthermore, we established a cotton protoplast system for transient gene expression to study gene functions by a gain-of-function approach. The viable protoplasts were isolated from green cotyledons, etiolated cotyledons, and true leaves, and responded to a wide range of pathogen elicitors and phytohormones. Remarkably, cotton plants possess conserved, but also distinct MAP kinase activation with Arabidopsis upon bacterial elicitor flagellin perception. Thus, we demonstrated that GhNDR1 and GhMKK2 are required for Verticillium resistance in cotton using gene silencing assays, and established the high throughput loss-of-function and gain-of-function assays for functional genomic studies in cotton. PMID:21219508

[Plant hormones, plant growth regulators].

PubMed

Végvári, György; Vidéki, Edina

2014-06-29

Plants seem to be rather defenceless, they are unable to do motion, have no nervous system or immune system unlike animals. Besides this, plants do have hormones, though these substances are produced not in glands. In view of their complexity they lagged behind animals, however, plant organisms show large scale integration in their structure and function. In higher plants, such as in animals, the intercellular communication is fulfilled through chemical messengers. These specific compounds in plants are called phytohormones, or in a wide sense, bioregulators. Even a small quantity of these endogenous organic compounds are able to regulate the operation, growth and development of higher plants, and keep the connection between cells, tissues and synergy between organs. Since they do not have nervous and immume systems, phytohormones play essential role in plants' life.

Effect of simulated microgravitation on phytohormones and cell structure of tropical orchids

NASA Astrophysics Data System (ADS)

Cherevchenko, T.; Zaimenko, N.; Majko, T.; Sytnjanskaja, N.

When studing the effect of two month clinostating on the phytohormonal system of orchids with different types of shoot system branching and different shoot morphology, it was determined that, as a result of simulated microgravitation, endogenous growth regulators changed less in the species with sympodial branching than in species with monopodial branching and without pseudobulbs. Stimulators prevail in the balance of growth regulators in species of the first type and inhibitors in species of the second type. Besides this, comparative analysis of structural organization of juvenile leaf surface tissue of tested orchids was carried out. Variability of size, number and structure of stomatal organization were found according to species belonging to each branching type after clinostating. Electronic microscope studies show some structural peculiarities of epidermal and mesophilous cells.

Glucose and phytohormone interplay in controlling root directional growth in Arabidopsis.

PubMed

Singh, Manjul; Gupta, Aditi; Laxmi, Ashverya

2014-01-01

Sensing and responding toward gravity vector is a complicated and multistep process. Gravity is a constant factor feeding plants with reliable information for the spatial orientation of their organs. Auxin, cytokinin, ethylene and BRs have been the most explored hormones in relation to gravitropism. We have previously shown that glucose (Glc) could promote brassinosteroid (BR) signaling thereby inducing changes in root directional growth. Auxin signaling and polar transport components are also involved in Glc induced changes in root directional growth. Here, we provide evidence for involvement of cytokinin and ethylene signaling components in regulation of root directional growth downstream to Glc and BR. Altogether, Glc mediated change in root direction is an adaptive feature which is a result of a collaborative effort integrating phytohormonal signaling cues.

Mapping International Cancer Activities – Global Cancer Project Map Launch

Cancer.gov

CGH’s Dr. Sudha Sivaram, Dr. Makeda Williams, and Ms. Kalina Duncan have partnered with Drs. Ami Bhatt and Franklin Huang at Global Oncology, Inc. (GO) to develop the Global Cancer Project Map - a web-based tool designed to facilitate cancer research and control activity planning.

Cytokinin production by Pseudomonas fluorescens G20-18 determines biocontrol activity against Pseudomonas syringae in Arabidopsis

PubMed Central

Großkinsky, Dominik K.; Tafner, Richard; Moreno, María V.; Stenglein, Sebastian A.; García de Salamone, Inés E.; Nelson, Louise M.; Novák, Ondřej; Strnad, Miroslav; van der Graaff, Eric; Roitsch, Thomas

2016-01-01

Plant beneficial microbes mediate biocontrol of diseases by interfering with pathogens or via strengthening the host. Although phytohormones, including cytokinins, are known to regulate plant development and physiology as well as plant immunity, their production by microorganisms has not been considered as a biocontrol mechanism. Here we identify the ability of Pseudomonas fluorescens G20-18 to efficiently control P. syringae infection in Arabidopsis, allowing maintenance of tissue integrity and ultimately biomass yield. Microbial cytokinin production was identified as a key determinant for this biocontrol effect on the hemibiotrophic bacterial pathogen. While cytokinin-deficient loss-of-function mutants of G20-18 exhibit impaired biocontrol, functional complementation with cytokinin biosynthetic genes restores cytokinin-mediated biocontrol, which is correlated with differential cytokinin levels in planta. Arabidopsis mutant analyses revealed the necessity of functional plant cytokinin perception and salicylic acid-dependent defence signalling for this biocontrol mechanism. These results demonstrate microbial cytokinin production as a novel microbe-based, hormone-mediated concept of biocontrol. This mechanism provides a basis to potentially develop novel, integrated plant protection strategies combining promotion of growth, a favourable physiological status and activation of fine-tuned direct defence and abiotic stress resilience. PMID:26984671

Cytokinin production by Pseudomonas fluorescens G20-18 determines biocontrol activity against Pseudomonas syringae in Arabidopsis.

PubMed

Großkinsky, Dominik K; Tafner, Richard; Moreno, María V; Stenglein, Sebastian A; García de Salamone, Inés E; Nelson, Louise M; Novák, Ondřej; Strnad, Miroslav; van der Graaff, Eric; Roitsch, Thomas

2016-03-17

Plant beneficial microbes mediate biocontrol of diseases by interfering with pathogens or via strengthening the host. Although phytohormones, including cytokinins, are known to regulate plant development and physiology as well as plant immunity, their production by microorganisms has not been considered as a biocontrol mechanism. Here we identify the ability of Pseudomonas fluorescens G20-18 to efficiently control P. syringae infection in Arabidopsis, allowing maintenance of tissue integrity and ultimately biomass yield. Microbial cytokinin production was identified as a key determinant for this biocontrol effect on the hemibiotrophic bacterial pathogen. While cytokinin-deficient loss-of-function mutants of G20-18 exhibit impaired biocontrol, functional complementation with cytokinin biosynthetic genes restores cytokinin-mediated biocontrol, which is correlated with differential cytokinin levels in planta. Arabidopsis mutant analyses revealed the necessity of functional plant cytokinin perception and salicylic acid-dependent defence signalling for this biocontrol mechanism. These results demonstrate microbial cytokinin production as a novel microbe-based, hormone-mediated concept of biocontrol. This mechanism provides a basis to potentially develop novel, integrated plant protection strategies combining promotion of growth, a favourable physiological status and activation of fine-tuned direct defence and abiotic stress resilience.

"When Did They Make the World Like This?" Discovering New Worlds through an Ancient Map.

ERIC Educational Resources Information Center

Goben, Victoria

1993-01-01

Describes a teaching activity in which middle school students draw maps based on map models used in ancient Babylon. Contends that this approach serves as a transition from the study of world civilizations in grade six to the U.S. history course in grade seven. Includes 10 student-created maps and student comments about the activity. (CFR)

Teaching Plate Tectonic Concepts using GeoMapApp Learning Activities

NASA Astrophysics Data System (ADS)

Goodwillie, A. M.; Kluge, S.

2012-12-01

GeoMapApp Learning Activities ( http://serc.carleton.edu/geomapapp/collection.html ) can help educators to expose undergraduate students to a range of earth science concepts using high-quality data sets in an easy-to-use map-based interface called GeoMapApp. GeoMapApp Learning Activities require students to interact with and analyse research-quality geoscience data as a means to explore and enhance their understanding of underlying content and concepts. Each activity is freely available through the SERC-Carleton web site and offers step-by-step student instructions and answer sheets. Also provided are annotated educator versions of the worksheets that include teaching tips, additional content and suggestions for further work. The activities can be used "off-the-shelf". Or, since the educator may require flexibility to tailor the activities, the documents are provided in Word format for easy modification. Examples of activities include one on the concept of seafloor spreading that requires students to analyse global seafloor crustal age data to calculate spreading rates in different ocean basins. Another activity has students explore hot spots using radiometric age dating of rocks along the Hawaiian-Emperor seamount chain. A third focusses upon the interactive use of contours and profiles to help students visualise 3-D topography on 2-D computer screens. A fourth activity provides a study of mass wasting as revealed through geomorphological evidence. The step-by-step instructions and guided inquiry approach reduce the need for teacher intervention whilst boosting the time that students can spend on productive exploration and learning. The activities can be used, for example, in a classroom lab with the educator present and as self-paced assignments in an out-of-class setting. GeoMapApp Learning Activities are funded through the NSF GeoEd program and are aimed at students in the introductory undergraduate, community college and high school levels. The activities are based upon GeoMapApp (http://www.geomapapp.org), a free map-based data exploration and visualisation tool that allows students to access a wide range of geoscience data in a virtual lab-like environment.

Mappability of drug-like space: towards a polypharmacologically competent map of drug-relevant compounds.

PubMed

Sidorov, Pavel; Gaspar, Helena; Marcou, Gilles; Varnek, Alexandre; Horvath, Dragos

2015-12-01

Intuitive, visual rendering--mapping--of high-dimensional chemical spaces (CS), is an important topic in chemoinformatics. Such maps were so far dedicated to specific compound collections--either limited series of known activities, or large, even exhaustive enumerations of molecules, but without associated property data. Typically, they were challenged to answer some classification problem with respect to those same molecules, admired for their aesthetical virtues and then forgotten--because they were set-specific constructs. This work wishes to address the question whether a general, compound set-independent map can be generated, and the claim of "universality" quantitatively justified, with respect to all the structure-activity information available so far--or, more realistically, an exploitable but significant fraction thereof. The "universal" CS map is expected to project molecules from the initial CS into a lower-dimensional space that is neighborhood behavior-compliant with respect to a large panel of ligand properties. Such map should be able to discriminate actives from inactives, or even support quantitative neighborhood-based, parameter-free property prediction (regression) models, for a wide panel of targets and target families. It should be polypharmacologically competent, without requiring any target-specific parameter fitting. This work describes an evolutionary growth procedure of such maps, based on generative topographic mapping, followed by the validation of their polypharmacological competence. Validation was achieved with respect to a maximum of exploitable structure-activity information, covering all of Homo sapiens proteins of the ChEMBL database, antiparasitic and antiviral data, etc. Five evolved maps satisfactorily solved hundreds of activity-based ligand classification challenges for targets, and even in vivo properties independent from training data. They also stood chemogenomics-related challenges, as cumulated responsibility vectors obtained by mapping of target-specific ligand collections were shown to represent validated target descriptors, complying with currently accepted target classification in biology. Therefore, they represent, in our opinion, a robust and well documented answer to the key question "What is a good CS map?"

A global tectonic activity map with orbital photographic supplement

NASA Technical Reports Server (NTRS)

Lowman, P. D., Jr.

1981-01-01

A three part map showing equatorial and polar regions was compiled showing tectonic and volcanic activity of the past one million years, including the present. Features shown include actively spreading ridges, spreading rates, major active faults, subduction zones, well defined plates, and volcanic areas active within the past one million years. Activity within this period was inferred from seismicity (instrumental and historic), physiography, and published literature. The tectonic activity map was used for planning global geodetic programs of satellite laser ranging and very long base line interferometry and for geologic education.

Space-Based Sensorweb Monitoring of Wildfires in Thailand

NASA Technical Reports Server (NTRS)

Chien, Steve; Doubleday, Joshua; Mclaren, David; Davies, Ashley; Tran, Daniel; Tanpipat, Veerachai; Akaakara, Siri; Ratanasuwan, Anuchit; Mandl, Daniel

2011-01-01

We describe efforts to apply sensorweb technologies to the monitoring of forest fires in Thailand. In this approach, satellite data and ground reports are assimilated to assess the current state of the forest system in terms of forest fire risk, active fires, and likely progression of fires and smoke plumes. This current and projected assessment can then be used to actively direct sensors and assets to best acquire further information. This process operates continually with new data updating models of fire activity leading to further sensing and updating of models. As the fire activity is tracked, products such as active fire maps, burn scar severity maps, and alerts are automatically delivered to relevant parties.We describe the current state of the Thailand Fire Sensorweb which utilizes the MODIS-based FIRMS system to track active fires and trigger Earth Observing One / Advanced Land Imager to acquire imagery and produce active fire maps, burn scar severity maps, and alerts. We describe ongoing work to integrate additional sensor sources and generate additional products.

Methyl jasmonate as a vital substance in plants.

PubMed

Cheong, Jong-Joo; Choi, Yang Do

2003-07-01

The plant floral scent methyl jasmonate (MeJA) has been identified as a vital cellular regulator that mediates diverse developmental processes and defense responses against biotic and abiotic stresses. The pleiotropic effects of MeJA have raised numerous questions about its regulation for biogenesis and mode of action. Characterization of the gene encoding jasmonic acid carboxyl methyltransferase has provided basic information on the role(s) of this phytohormone in gene-activation control and systemic long-distance signaling. Recent approaches using functional genomics and bioinformatics have identified a whole set of MeJA-responsive genes, and provide insights into how plants use volatile signals to withstand diverse and variable environments.

Profiling of phytohormones and their major metabolites in rice using binary solid-phase extraction and liquid chromatography-triple quadrupole mass spectrometry.

PubMed

Cao, Zhao-Yun; Sun, Li-Hua; Mou, Ren-Xiang; Zhang, Lin-Ping; Lin, Xiao-Yan; Zhu, Zhi-Wei; Chen, Ming-Xue

2016-06-17

A high-throughput method was developed using liquid chromatography-triple quadrupole mass spectrometry (LC-MS/MS) for the profiling and quantification of 43 phytohormones and their major metabolites, including auxins, abscisic acid, jasmonic acid, salicylic acid, cytokinins and gibberellins in a single sample extract. Considerable matrix effects (MEs) were observed (with most ME values in the range of 29%-84%, but maximum MEs of more than 115%, even up to 206%, existed) in sample extracts for most of the compounds studied. The application of the proposed binary solid-phase extraction using polymer anion and polymer cation exchange resins, was performed to purify 25 acidic and 18 alkaline phytohormones and their major metabolites prior to the LC-MS/MS analysis, which markedly reduced the MEs to acceptable levels, with ME values in the range of ±15%. Moreover, all of the isomers of cytokinins and their metabolites were fully separated on a sub-2μm particle C18 reverse-phase column with the optimized mobile phase consisting of methanol and 5mM ammonium formate. The method showed good linearity for all 43 analytes with regression coefficients (R(2))>0.991. Limits of detection ranged from 0.19 to 7.57 fmol for auxin, gibberellins, abscisic acid and their metabolites, 29.7 fmol for jasmonic acid, 18.1 fmol for salicylic acid, and from 0.03 to 0.31 fmol for cytokinins and their metabolites. The mean recoveries for all of the analytes were from 70.7 to 118.5%, and the inter-day precisions (n=6) were less than 18.7%, with intra-day precisions (n=6) within 25.4%. Finally, 20 compounds were successfully quantified in rice sample profiles using the proposed method, which will greatly facilitate the understanding of hormone-related regulatory networks that influence rice growth and development. To our knowledge, there are limited reports that measure this level of phytohormone species in rice samples using a single analysis. Copyright © 2016 Elsevier B.V. All rights reserved.

Specificity of herbivore-induced hormonal signaling and defensive traits in five closely related milkweeds (Asclepias spp.).

PubMed

Agrawal, Anurag A; Hastings, Amy P; Patrick, Eamonn T; Knight, Anna C

2014-07-01

Despite the recognition that phytohormonal signaling mediates induced responses to herbivory, we still have little understanding of how such signaling varies among closely related species and may generate herbivore-specific induced responses. We studied closely related milkweeds (Asclepias) to link: 1) plant damage by two specialist chewing herbivores (milkweed leaf beetles Labidomera clivicolis and monarch caterpillars Danaus plexippus); 2) production of the phytohormones jasmonic acid (JA), salicylic acid (SA), and abscisic acid (ABA); 3) induction of defensive cardenolides and latex; and 4) impacts on Danaus caterpillars. We first show that A. syriaca exhibits induced resistance following monarch herbivory (i.e., reduced monarch growth on previously damaged plants), while the defensively dissimilar A. tuberosa does not. We next worked with a broader group of five Asclepias, including these two species, that are highly divergent in defensive traits yet from the same clade. Three of the five species showed herbivore-induced changes in cardenolides, while induced latex was found in four species. Among the phytohormones, JA and ABA showed specific responses (although they generally increased) to insect species and among the plant species. In contrast, SA responses were consistent among plant and herbivore species, showing a decline following herbivore attack. Jasmonic acid showed a positive quantitative relationship only with latex, and this was strongest in plants damaged by D. plexippus. Although phytohormones showed qualitative tradeoffs (i.e., treatments that enhanced JA reduced SA), the few significant individual plant-level correlations among hormones were positive, and these were strongest between JA and ABA in monarch damaged plants. We conclude that: 1) latex exudation is positively associated with endogenous JA levels, even among low-latex species; 2) correlations among milkweed hormones are generally positive, although herbivore damage induces a divergence (tradeoff) between JA and SA; 3) induction of cardenolides and latex are not necessarily physiologically linked; and 4) even very closely related species show highly divergent induction, with some species showing strong defenses, hormonally-mediated induction, and impacts on herbivores, while other milkweed species apparently use alternative strategies to cope with insect attack.

GeoMapApp Learning Activities: Enabling the democratisation of geoscience learning

NASA Astrophysics Data System (ADS)

Goodwillie, A. M.; Kluge, S.

2011-12-01

GeoMapApp Learning Activities (http://serc.carleton.edu/geomapapp) are step-by-step guided inquiry geoscience education activities that enable students to dictate the pace of learning. They can be used in the classroom or out of class, and their guided nature means that the requirement for teacher intervention is minimised which allows students to spend increased time analysing and understanding a broad range of geoscience data, content and concepts. Based upon GeoMapApp (http://www.geomapapp.org), a free, easy-to-use map-based data exploration and visualisation tool, each activity furnishes the educator with an efficient package of downloadable documents. This includes step-by-step student instructions and answer sheet; a teacher's edition annotated worksheet containing teaching tips, additional content and suggestions for further work; quizzes for use before and after the activity to assess learning; and a multimedia tutorial. The activities can be used by anyone at any time in any place with an internet connection. In essence, GeoMapApp Learning Activities provide students with cutting-edge technology, research-quality geoscience data sets, and inquiry-based learning in a virtual lab-like environment. Examples of activities so far created are student calculation and analysis of the rate of seafloor spreading, and present-day evidence on the seafloor for huge ancient landslides around the Hawaiian islands. The activities are designed primarily for students at the community college, high school and introductory undergraduate levels, exposing students to content and concepts typically found in those settings.

Antagonism between salicylic and abscisic acid reflects early host-pathogen conflict and moulds plant defence responses.

PubMed

de Torres Zabala, Marta; Bennett, Mark H; Truman, William H; Grant, Murray R

2009-08-01

The importance of phytohormone balance is increasingly recognized as central to the outcome of plant-pathogen interactions. Recently it has been demonstrated that abscisic acid signalling pathways are utilized by the bacterial phytopathogen Pseudomonas syringae to promote pathogenesis. In this study, we examined the dynamics, inter-relationship and impact of three key acidic phytohormones, salicylic acid, abscisic acid and jasmonic acid, and the bacterial virulence factor, coronatine, during progression of P. syringae infection of Arabidopsis thaliana. We show that levels of SA and ABA, but not JA, appear to play important early roles in determining the outcome of the infection process. SA is required in order to mount a full innate immune responses, while bacterial effectors act rapidly to activate ABA biosynthesis. ABA suppresses inducible innate immune responses by down-regulating SA biosynthesis and SA-mediated defences. Mutant analyses indicated that endogenous ABA levels represent an important reservoir that is necessary for effector suppression of plant-inducible innate defence responses and SA synthesis prior to subsequent pathogen-induced increases in ABA. Enhanced susceptibility due to loss of SA-mediated basal resistance is epistatically dominant over acquired resistance due to ABA deficiency, although ABA also contributes to symptom development. We conclude that pathogen-modulated ABA signalling rapidly antagonizes SA-mediated defences. We predict that hormonal perturbations, either induced or as a result of environmental stress, have a marked impact on pathological outcomes, and we provide a mechanistic basis for understanding priming events in plant defence.

Autophagy-related direct membrane import from ER/cytoplasm into the vacuole or apoplast: a hidden gateway also for secondary metabolites and phytohormones?

PubMed

Kulich, Ivan; Žárský, Viktor

2014-04-29

Transportation of low molecular weight cargoes into the plant vacuole represents an essential plant cell function. Several lines of evidence indicate that autophagy-related direct endoplasmic reticulum (ER) to vacuole (and also, apoplast) transport plays here a more general role than expected. This route is regulated by autophagy proteins, including recently discovered involvement of the exocyst subcomplex. Traffic from ER into the vacuole bypassing Golgi apparatus (GA) acts not only in stress-related cytoplasm recycling or detoxification, but also in developmentally-regulated biopolymer and secondary metabolite import into the vacuole (or apoplast), exemplified by storage proteins and anthocyanins. We propose that this pathway is relevant also for some phytohormones' (e.g., auxin, abscisic acid (ABA) and salicylic acid (SA)) degradation. We hypothesize that SA is not only an autophagy inducer, but also a cargo for autophagy-related ER to vacuole membrane container delivery and catabolism. ER membrane localized enzymes will potentially enhance the area of biosynthetic reactive surfaces, and also, abundant ER localized membrane importers (e.g., ABC transporters) will internalize specific molecular species into the autophagosome biogenesis domain of ER. Such active ER domains may create tubular invaginations of tonoplast into the vacuoles as import intermediates. Packaging of cargos into the ER-derived autophagosome-like containers might be an important mechanism of vacuole and exosome biogenesis and cytoplasm protection against toxic metabolites. A new perspective on metabolic transformations intimately linked to membrane trafficking in plants is emerging.

Silicon mitigates heavy metal stress by regulating P-type heavy metal ATPases, Oryza sativa low silicon genes, and endogenous phytohormones

PubMed Central

2014-01-01

Background Silicon (Si) application has been known to enhance the tolerance of plants against abiotic stresses. However, the protective mechanism of Si under heavy metals contamination is poorly understood. The aim of this study was to assess the role of Si in counteracting toxicity due to cadmium (Cd) and copper (Cu) in rice plants (Oryza sativa). Results Si significantly improved the growth and biomass of rice plants and reduced the toxic effects of Cd/Cu after different stress periods. Si treatment ameliorated root function and structure compared with non-treated rice plants, which suffered severe root damage. In the presence of Si, the Cd/Cu concentration was significantly lower in rice plants, and there was also a reduction in lipid peroxidation and fatty acid desaturation in plant tissues. The reduced uptake of metals in the roots modulated the signaling of phytohormones involved in responses to stress and host defense, such as abscisic acid, jasmonic acid, and salicylic acid. Furthermore, the low concentration of metals significantly down regulated the mRNA expression of enzymes encoding heavy metal transporters (OsHMA2 and OsHMA3) in Si-metal-treated rice plants. Genes responsible for Si transport (OsLSi1 and OsLSi2), showed a significant up-regulation of mRNA expression with Si treatment in rice plants. Conclusion The present study supports the active role of Si in the regulation of stresses from heavy metal exposure through changes in root morphology. PMID:24405887

Mappability of drug-like space: towards a polypharmacologically competent map of drug-relevant compounds

NASA Astrophysics Data System (ADS)

Sidorov, Pavel; Gaspar, Helena; Marcou, Gilles; Varnek, Alexandre; Horvath, Dragos

2015-12-01

Intuitive, visual rendering—mapping—of high-dimensional chemical spaces (CS), is an important topic in chemoinformatics. Such maps were so far dedicated to specific compound collections—either limited series of known activities, or large, even exhaustive enumerations of molecules, but without associated property data. Typically, they were challenged to answer some classification problem with respect to those same molecules, admired for their aesthetical virtues and then forgotten—because they were set-specific constructs. This work wishes to address the question whether a general, compound set-independent map can be generated, and the claim of "universality" quantitatively justified, with respect to all the structure-activity information available so far—or, more realistically, an exploitable but significant fraction thereof. The "universal" CS map is expected to project molecules from the initial CS into a lower-dimensional space that is neighborhood behavior-compliant with respect to a large panel of ligand properties. Such map should be able to discriminate actives from inactives, or even support quantitative neighborhood-based, parameter-free property prediction (regression) models, for a wide panel of targets and target families. It should be polypharmacologically competent, without requiring any target-specific parameter fitting. This work describes an evolutionary growth procedure of such maps, based on generative topographic mapping, followed by the validation of their polypharmacological competence. Validation was achieved with respect to a maximum of exploitable structure-activity information, covering all of Homo sapiens proteins of the ChEMBL database, antiparasitic and antiviral data, etc. Five evolved maps satisfactorily solved hundreds of activity-based ligand classification challenges for targets, and even in vivo properties independent from training data. They also stood chemogenomics-related challenges, as cumulated responsibility vectors obtained by mapping of target-specific ligand collections were shown to represent validated target descriptors, complying with currently accepted target classification in biology. Therefore, they represent, in our opinion, a robust and well documented answer to the key question "What is a good CS map?"

SlWRKY45, nematode-responsive tomato WRKY gene, enhances susceptibility to the root knot nematode; M. javanica infection.

PubMed

Chinnapandi, Bharathiraja; Bucki, Patricia; Braun Miyara, Sigal

2017-12-02

The fluctuation of tomato's WRKY defense regulators during infection by the root knot nematode Meloidogyne javanica was analyzed: and the spatial and temporal expression of SlWRKY45 was studied in depth with regard to its response to nematode infection, phytohormones, and wounding. Expression of WRKY45 increased substantially within 5 d upon infection and continued through feeding-site development and gall maturation. Histological analysis of nematode feeding sites indicated that WRKY45 was highly expressed within the feeding cells and associated vascular parenchyma cells. Responses of SlWRKY45 promoters to several phytohormones showed that WRKY45 was highly induced by specific phytohormones, including cytokinin, auxin, and the defense-signaling molecule salicylic acid (SA), but not by the jasmonates. Overexpressing tomato lines were generated, and infection tests showed that, significantly, roots over-expressing SlWRKY45 contained substantially increased number of females, indicating that WRKY45 overexpression supported faster nematode development. qRT-PCR tests have shown roots overexpressing WRKY45 suppressed the jasmonic acid and salicylic acid marker genes, proteinase inhibitor (PI), and pathogenesis related protein (PR1), respectively, and also the cytokinin response factors CRF1 and CRF6. Overall, this study indicated SlWRKY45 to be a potential transcription factor whose manipulation by the invading nematode might be critical for coordination of hormone signals supporting favorable condition for nematode development in root tissue.

The Calcium-Dependent Protein Kinase CPK28 Regulates Development by Inducing Growth Phase-Specific, Spatially Restricted Alterations in Jasmonic Acid Levels Independent of Defense Responses in Arabidopsis[OPEN

PubMed Central

Matschi, Susanne; Hake, Katharina; Herde, Marco; Hause, Bettina; Romeis, Tina

2015-01-01

Phytohormones play an important role in development and stress adaptations in plants, and several interacting hormonal pathways have been suggested to accomplish fine-tuning of stress responses at the expense of growth. This work describes the role played by the CALCIUM-DEPENDENT PROTEIN KINASE CPK28 in balancing phytohormone-mediated development in Arabidopsis thaliana, specifically during generative growth. cpk28 mutants exhibit growth reduction solely as adult plants, coinciding with altered balance of the phytohormones jasmonic acid (JA) and gibberellic acid (GA). JA-dependent gene expression and the levels of several JA metabolites were elevated in a growth phase-dependent manner in cpk28, and accumulation of JA metabolites was confined locally to the central rosette tissue. No elevated resistance toward herbivores or necrotrophic pathogens was detected for cpk28 plants, either on the whole-plant level or specifically within the tissue displaying elevated JA levels. Abolishment of JA biosynthesis or JA signaling led to a full reversion of the cpk28 growth phenotype, while modification of GA signaling did not. Our data identify CPK28 as a growth phase-dependent key negative regulator of distinct processes: While in seedlings, CPK28 regulates reactive oxygen species-mediated defense signaling; in adult plants, CPK28 confers developmental processes by the tissue-specific balance of JA and GA without affecting JA-mediated defense responses. PMID:25736059

Applying the Intervention Mapping protocol to develop a kindergarten-based, family-involved intervention to increase European preschool children's physical activity levels: the ToyBox-study.

PubMed

De Craemer, M; De Decker, E; De Bourdeaudhuij, I; Verloigne, M; Duvinage, K; Koletzko, B; Ibrügger, S; Kreichauf, S; Grammatikaki, E; Moreno, L; Iotova, V; Socha, P; Szott, K; Manios, Y; Cardon, G

2014-08-01

Although sufficient physical activity is beneficial for preschoolers' health, activity levels in most preschoolers are low. As preschoolers spend a considerable amount of time at home and at kindergarten, interventions should target both environments to increase their activity levels. The aim of the current paper was to describe the six different steps of the Intervention Mapping protocol towards the systematic development and implementation of the physical activity component of the ToyBox-intervention. This intervention is a kindergarten-based, family-involved intervention implemented across six European countries. Based on the results of literature reviews and focus groups with parents/caregivers and kindergarten teachers, matrices of change objectives were created. Then, theory-based methods and practical strategies were selected to develop intervention materials at three different levels: (i) individual level (preschoolers); (ii) interpersonal level (parents/caregivers) and (iii) organizational level (teachers). This resulted in a standardized intervention with room for local and cultural adaptations in each participating country. Although the Intervention Mapping protocol is a time-consuming process, using this systematic approach may lead to an increase in intervention effectiveness. The presented matrices of change objectives are useful for future programme planners to develop and implement an intervention based on the Intervention Mapping protocol to increase physical activity levels in preschoolers. © 2014 World Obesity.

GeoMapApp Learning Activities: Grab-and-go inquiry-based geoscience activities that bring cutting-edge technology to the classroom

NASA Astrophysics Data System (ADS)

Goodwillie, A. M.; Kluge, S.

2011-12-01

NSF-funded GeoMapApp Learning Activities (http://serc.carleton.edu/geomapapp) provide self-contained learning opportunities that are centred around the principles of guided inquiry. The activities allow students to interact with and analyse research-quality geoscience data to explore and enhance student understanding of underlying geoscience content and concepts. Each activity offers ready-to-use step-by-step student instructions and answer sheets that can be downloaded from the web page. Also provided are annotated teacher versions of the worksheets that include teaching tips, additional content and suggestions for further work. Downloadable pre- and post- quizzes tied to each activity help educators gauge the learning progression of their students. Short multimedia tutorials and details on content alignment with state and national teaching standards round out the package of material that comprises each "grab-and-go" activity. GeoMapApp Learning Activities expose students to content and concepts typically found at the community college, high school and introductory undergraduate levels. The activities are based upon GeoMapApp (http://www.geomapapp.org), a free, easy-to-use map-based data exploration and visualisation tool that allows students to access a wide range of geoscience data sets in a virtual lab-like environment. Activities that have so far been created under this project include student exploration of seafloor spreading rates, a study of mass wasting as revealed through geomorphological evidence, and an analysis of plate motion and hotspot traces. The step-by-step instructions and guided inquiry approach lead students through each activity, thus reducing the need for teacher intervention whilst also boosting the time that students can spend on productive exploration and learning. The activities can be used, for example, in a classroom lab with the educator present and as self-paced assignments in an out-of-class setting. GeoMapApp Learning Activities are hosted on the SERC-Carleton web site.

Technical Note: A 3-D rendering algorithm for electromechanical wave imaging of a beating heart.

PubMed

Nauleau, Pierre; Melki, Lea; Wan, Elaine; Konofagou, Elisa

2017-09-01

Arrhythmias can be treated by ablating the heart tissue in the regions of abnormal contraction. The current clinical standard provides electroanatomic 3-D maps to visualize the electrical activation and locate the arrhythmogenic sources. However, the procedure is time-consuming and invasive. Electromechanical wave imaging is an ultrasound-based noninvasive technique that can provide 2-D maps of the electromechanical activation of the heart. In order to fully visualize the complex 3-D pattern of activation, several 2-D views are acquired and processed separately. They are then manually registered with a 3-D rendering software to generate a pseudo-3-D map. However, this last step is operator-dependent and time-consuming. This paper presents a method to generate a full 3-D map of the electromechanical activation using multiple 2-D images. Two canine models were considered to illustrate the method: one in normal sinus rhythm and one paced from the lateral region of the heart. Four standard echographic views of each canine heart were acquired. Electromechanical wave imaging was applied to generate four 2-D activation maps of the left ventricle. The radial positions and activation timings of the walls were automatically extracted from those maps. In each slice, from apex to base, these values were interpolated around the circumference to generate a full 3-D map. In both cases, a 3-D activation map and a cine-loop of the propagation of the electromechanical wave were automatically generated. The 3-D map showing the electromechanical activation timings overlaid on realistic anatomy assists with the visualization of the sources of earlier activation (which are potential arrhythmogenic sources). The earliest sources of activation corresponded to the expected ones: septum for the normal rhythm and lateral for the pacing case. The proposed technique provides, automatically, a 3-D electromechanical activation map with a realistic anatomy. This represents a step towards a noninvasive tool to efficiently localize arrhythmias in 3-D. © 2017 American Association of Physicists in Medicine.

Overexpression of BnWRKY33 in oilseed rape enhances resistance to Sclerotinia sclerotiorum.

PubMed

Wang, Zheng; Fang, Hedi; Chen, Yu; Chen, Keping; Li, Guanying; Gu, Shoulai; Tan, Xiaoli

2014-09-01

Sclerotinia sclerotiorum causes a devastating disease in oilseed rape (Brassica napus) resulting in a tremendous yield loss worldwide. Studies on various host-pathogen interactions have shown that plant WRKY transcription factors are essential for defence. For the B. napus-S. sclerotiorum interaction, little direct evidence has been found with regard to the biological roles of specific WRKY genes in host resistance. In this study, we isolated a B. napus WRKY gene, BnWRKY33, and found that the gene is highly responsive to S. sclerotiorum infection. Transgenic B. napus plants overexpressing BnWRKY33 showed markedly enhanced resistance to S. sclerotiorum, constitutive activation of the expression of BnPR1 and BnPDF1.2, and inhibition of H2 O2 accumulation in response to pathogen infection. Further, we isolated a mitogen-activated protein (MAP) kinase substrate gene, BnMKS1, and found that not only can BnWRKY33 interact with BnMKS1, which can also interact with BnMPK4, using the yeast two-hybrid assay, consistent with their collective nuclear localization, but also BnWRKY33, BnMKS1 and BnMPK4 are substantially and synergistically expressed in response to S. sclerotiorum infection. In contrast, the three genes showed differential expression in response to phytohormone treatments. Together, these results suggest that BnWRKY33 plays an important role in B. napus defence to S. sclerotiorum, which is most probably associated with the activation of the salicylic acid (SA)- and jasmonic acid (JA)-mediated defence response and inhibition of H2 O2 accumulation, and we propose a potential mechanism in which BnMPK4-BnMKS1-BnWRKY33 exist in a nuclear localized complex to regulate resistance to S. sclerotiorum in oilseed rape. © 2014 BSPP AND JOHN WILEY & SONS LTD.

Genetic architecture of plant stress resistance: multi-trait genome-wide association mapping.

PubMed

Thoen, Manus P M; Davila Olivas, Nelson H; Kloth, Karen J; Coolen, Silvia; Huang, Ping-Ping; Aarts, Mark G M; Bac-Molenaar, Johanna A; Bakker, Jaap; Bouwmeester, Harro J; Broekgaarden, Colette; Bucher, Johan; Busscher-Lange, Jacqueline; Cheng, Xi; Fradin, Emilie F; Jongsma, Maarten A; Julkowska, Magdalena M; Keurentjes, Joost J B; Ligterink, Wilco; Pieterse, Corné M J; Ruyter-Spira, Carolien; Smant, Geert; Testerink, Christa; Usadel, Björn; van Loon, Joop J A; van Pelt, Johan A; van Schaik, Casper C; van Wees, Saskia C M; Visser, Richard G F; Voorrips, Roeland; Vosman, Ben; Vreugdenhil, Dick; Warmerdam, Sonja; Wiegers, Gerrie L; van Heerwaarden, Joost; Kruijer, Willem; van Eeuwijk, Fred A; Dicke, Marcel

2017-02-01

Plants are exposed to combinations of various biotic and abiotic stresses, but stress responses are usually investigated for single stresses only. Here, we investigated the genetic architecture underlying plant responses to 11 single stresses and several of their combinations by phenotyping 350 Arabidopsis thaliana accessions. A set of 214 000 single nucleotide polymorphisms (SNPs) was screened for marker-trait associations in genome-wide association (GWA) analyses using tailored multi-trait mixed models. Stress responses that share phytohormonal signaling pathways also share genetic architecture underlying these responses. After removing the effects of general robustness, for the 30 most significant SNPs, average quantitative trait locus (QTL) effect sizes were larger for dual stresses than for single stresses. Plants appear to deploy broad-spectrum defensive mechanisms influencing multiple traits in response to combined stresses. Association analyses identified QTLs with contrasting and with similar responses to biotic vs abiotic stresses, and below-ground vs above-ground stresses. Our approach allowed for an unprecedented comprehensive genetic analysis of how plants deal with a wide spectrum of stress conditions. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

A limit-cycle self-organizing map architecture for stable arm control.

PubMed

Huang, Di-Wei; Gentili, Rodolphe J; Katz, Garrett E; Reggia, James A

2017-01-01

Inspired by the oscillatory nature of cerebral cortex activity, we recently proposed and studied self-organizing maps (SOMs) based on limit cycle neural activity in an attempt to improve the information efficiency and robustness of conventional single-node, single-pattern representations. Here we explore for the first time the use of limit cycle SOMs to build a neural architecture that controls a robotic arm by solving inverse kinematics in reach-and-hold tasks. This multi-map architecture integrates open-loop and closed-loop controls that learn to self-organize oscillatory neural representations and to harness non-fixed-point neural activity even for fixed-point arm reaching tasks. We show through computer simulations that our architecture generalizes well, achieves accurate, fast, and smooth arm movements, and is robust in the face of arm perturbations, map damage, and variations of internal timing parameters controlling the flow of activity. A robotic implementation is evaluated successfully without further training, demonstrating for the first time that limit cycle maps can control a physical robot arm. We conclude that architectures based on limit cycle maps can be organized to function effectively as neural controllers. Copyright © 2016 Elsevier Ltd. All rights reserved.

A New Paradigm for Individual Subject Language Mapping: Movie-Watching fMRI.

PubMed

Tie, Yanmei; Rigolo, Laura; Ozdemir Ovalioglu, Aysegul; Olubiyi, Olutayo; Doolin, Kelly L; Mukundan, Srinivasan; Golby, Alexandra J

2015-01-01

Functional MRI (fMRI) based on language tasks has been used in presurgical language mapping in patients with lesions in or near putative language areas. However, if patients have difficulty performing the tasks due to neurological deficits, it leads to unreliable or noninterpretable results. In this study, we investigate the feasibility of using a movie-watching fMRI for language mapping. A 7-minute movie clip with contrasting speech and nonspeech segments was shown to 22 right-handed healthy subjects. Based on all subjects' language functional regions-of-interest, 6 language response areas were defined, within which a language response model (LRM) was derived by extracting the main temporal activation profile. Using a leave-one-out procedure, individuals' language areas were identified as the areas that expressed highly correlated temporal responses with the LRM derived from an independent group of subjects. Compared with an antonym generation task-based fMRI, the movie-watching fMRI generated language maps with more localized activations in the left frontal language area, larger activations in the left temporoparietal language area, and significant activations in their right-hemisphere homologues. Results of 2 brain tumor patients' movie-watching fMRI using the LRM derived from the healthy subjects indicated its ability to map putative language areas; while their task-based fMRI maps were less robust and noisier. These results suggest that it is feasible to use this novel "task-free" paradigm as a complementary tool for fMRI language mapping when patients cannot perform the tasks. Its deployment in more neurosurgical patients and validation against gold-standard techniques need further investigation. Copyright © 2015 by the American Society of Neuroimaging.

A new paradigm for individual subject language mapping: Movie-watching fMRI

PubMed Central

Tie, Yanmei; Rigolo, Laura; Ovalioglu, Aysegul Ozdemir; Olubiyi, Olutayo; Doolin, Kelly L.; Mukundan, Srinivasan; Golby, Alexandra J.

2015-01-01

Background Functional MRI (fMRI) based on language tasks has been used in pre-surgical language mapping in patients with lesions in or near putative language areas. However, if the patients have difficulty performing the tasks due to neurological deficits, it leads to unreliable or non-interpretable results. In this study, we investigate the feasibility of using a movie-watching fMRI for language mapping. Methods A 7-min movie clip with contrasting speech and non-speech segments was shown to 22 right-handed healthy subjects. Based on all subjects' language functional regions-of-interest, six language response areas were defined, within which a language response model (LRM) was derived by extracting the main temporal activation profile. Using a leave-one-out procedure, individuals' language areas were identified as the areas that expressed highly correlated temporal responses with the LRM derived from an independent group of subjects. Results Compared with an antonym generation task-based fMRI, the movie-watching fMRI generated language maps with more localized activations in the left frontal language area, larger activations in the left temporoparietal language area, and significant activations in their right-hemisphere homologues. Results of two brain tumor patients' movie-watching fMRI using the LRM derived from the healthy subjects indicated its ability to map putative language areas; while their task-based fMRI maps were less robust and noisier. Conclusions These results suggest that it is feasible to use this novel “task-free” paradigm as a complementary tool for fMRI language mapping when patients cannot perform the tasks. Its deployment in more neurosurgical patients and validation against gold-standard techniques need further investigation. PMID:25962953

Multi-component intrinsic brain activities as a safe, alternative to cortical stimulation for sensori-motor mapping in neurosurgery.

PubMed

Neshige, Shuichiro; Matsuhashi, Masao; Kobayashi, Katsuya; Sakurai, Takeyo; Shimotake, Akihiro; Hitomi, Takefumi; Kikuchi, Takayuki; Yoshida, Kazumichi; Kunieda, Takeharu; Matsumoto, Riki; Takahashi, Ryosuke; Miyamoto, Susumu; Maruyama, Hirofumi; Matsumoto, Masayasu; Ikeda, Akio

2018-06-18

To assess the feasibility of multi-component electrocorticography (ECoG)-based mapping using "wide-spectrum, intrinsic-brain activities" for identifying the primary sensori-motor area (S1-M1) by comparing that using electrical cortical stimulation (ECS). We evaluated 14 epilepsy patients with 1514 subdural electrodes implantation covering the perirolandic cortices at Kyoto University Hospital between 2011 and 2016. We performed multi-component, ECoG-based mapping (band-pass filter, 0.016-300/600 Hz) involving combined analyses of the single components: movement-related cortical potential (<0.5-1 Hz), event-related synchronization (76-200 Hz), and event-related de-synchronization (8-24 Hz) to identify the S1-M1. The feasibility of multi-component mapping was assessed through comparisons with single-component mapping and ECS. Among 54 functional areas evaluation, ECoG-based maps showed significantly higher rate of localization concordances with ECS maps when the three single-component maps were consistent than when those were inconsistent with each other (p < 0.001 in motor, and p = 0.02 in sensory mappings). Multi-component mapping revealed high sensitivity (89-90%) and specificity (94-97%) as compared with ECS. Wide-spectrum, multi-component ECoG-based mapping is feasible, having high sensitivity/specificity relative to ECS. This safe (non-stimulus) mapping strategy, alternative to ECS, would allow clinicians to rule in/out the possibility of brain function prior to resection surgery. Copyright © 2018 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Mapping with Young Children.

ERIC Educational Resources Information Center

Sunal, Cynthia Szymanski; Warash, Bobbi Gibson

Techniques for encouraging young children to discover the purpose and use of maps are discussed. Motor activity and topological studies form a base from which the teacher and children can build a mapping program of progressive sophistication. Concepts important to mapping include boundaries, regions, exteriors, interiors, holes, order, point of…

Decoding natural images from evoked brain activities using encoding models with invertible mapping.

PubMed

Li, Chao; Xu, Junhai; Liu, Baolin

2018-05-21

Recent studies have built encoding models in the early visual cortex, and reliable mappings have been made between the low-level visual features of stimuli and brain activities. However, these mappings are irreversible, so that the features cannot be directly decoded. To solve this problem, we designed a sparse framework-based encoding model that predicted brain activities from a complete feature representation. Moreover, according to the distribution and activation rules of neurons in the primary visual cortex (V1), three key transformations were introduced into the basic feature to improve the model performance. In this setting, the mapping was simple enough that it could be inverted using a closed-form formula. Using this mapping, we designed a hybrid identification method based on the support vector machine (SVM), and tested it on a published functional magnetic resonance imaging (fMRI) dataset. The experiments confirmed the rationality of our encoding model, and the identification accuracies for 2 subjects increased from 92% and 72% to 98% and 92% with the chance level only 0.8%. Copyright © 2018 Elsevier Ltd. All rights reserved.

Salicylic acid induces vanillin synthesis through the phospholipid signaling pathway in Capsicum chinense cell cultures

PubMed Central

Rodas-Junco, Beatriz A; Cab-Guillen, Yahaira; Muñoz-Sanchez, J Armando; Vázquez-Flota, Felipe; Monforte-Gonzalez, Miriam; Hérnandez-Sotomayor, S M Teresa

2013-01-01

Signal transduction via phospholipids is mediated by phospholipases such as phospholipase C (PLC) and D (PLD), which catalyze hydrolysis of plasma membrane structural phospholipids. Phospholipid signaling is also involved in plant responses to phytohormones such as salicylic acid (SA). The relationships between phospholipid signaling, SA, and secondary metabolism are not fully understood. Using a Capsicum chinense cell suspension as a model, we evaluated whether phospholipid signaling modulates SA-induced vanillin production through the activation of phenylalanine ammonia lyase (PAL), a key enzyme in the biosynthetic pathway. Salicylic acid was found to elicit PAL activity and consequently vanillin production, which was diminished or reversed upon exposure to the phosphoinositide-phospholipase C (PI-PLC) signaling inhibitors neomycin and U73122. Exposure to the phosphatidic acid inhibitor 1-butanol altered PLD activity and prevented SA-induced vanillin production. Our results suggest that PLC and PLD-generated secondary messengers may be modulating SA-induced vanillin production through the activation of key biosynthetic pathway enzymes.

Light Requirement for Shoot Regeneration in Horseradish Hairy Roots 1

PubMed Central

Saitou, Tsutomu; Kamada, Hiroshi; Harada, Hiroshi

1992-01-01

Hairy roots of horseradish (Armoracia rusticana) were induced by inoculation with Agrobacterium rhizogenes harboring Ri plasmid and cultured on phytohormone-free Murashige and Skoog medium after eliminating the bacteria. Hairy roots grew vigorously and sometimes formed yellowish calli under dark conditions. On the other hand, growth of hairy roots stopped after several weeks of culture with light, then shoots were regenerated. Frequency of shoot formation from hairy roots increased as the culture period in light lengthened and the light intensity increased. The shoot regeneration was induced by treatment with white or red light, but not with far-red light. Shoot regeneration by red light was inhibited by following treatment with far-red light. Red and far-red light reversibly affected shoot regeneration. Excised roots of nontransformed plants grew quite slowly on phytohormone-free Murashige and Skoog medium and occasionally formed shoots under white light conditions. PMID:16669041

Light requirement for shoot regeneration in horseradish hairy roots.

PubMed

Saitou, T; Kamada, H; Harada, H

1992-08-01

Hairy roots of horseradish (Armoracia rusticana) were induced by inoculation with Agrobacterium rhizogenes harboring Ri plasmid and cultured on phytohormone-free Murashige and Skoog medium after eliminating the bacteria. Hairy roots grew vigorously and sometimes formed yellowish calli under dark conditions. On the other hand, growth of hairy roots stopped after several weeks of culture with light, then shoots were regenerated. Frequency of shoot formation from hairy roots increased as the culture period in light lengthened and the light intensity increased. The shoot regeneration was induced by treatment with white or red light, but not with far-red light. Shoot regeneration by red light was inhibited by following treatment with far-red light. Red and far-red light reversibly affected shoot regeneration. Excised roots of nontransformed plants grew quite slowly on phytohormone-free Murashige and Skoog medium and occasionally formed shoots under white light conditions.

Small RNA-seq analysis in response to methyl jasmonate and abscisic acid treatment in Persicaria minor.

PubMed

Nazaruddin, Nazaruddin; Samad, Abdul Fatah A; Sajad, Muhammad; Jani, Jaeyres; Zainal, Zamri; Ismail, Ismanizan

2017-06-01

Persicaria minor (Kesum) is an important medicinal plant with high level of secondary metabolite contents, especially, terpenoids and flavonoids. Previous studies have revealed that application of exogenous phytohormone could increase secondary metabolite contents of the plant. MicroRNAs (miRNAs) are small RNAs that play important regulatory roles in various biological processes. In order to explore the possible role of miRNA in the regulation of these phytohormones signaling pathway and uncovering their potential correlation, we, for the first time, have generated the smallRNA library of Kesum plant. The library was developed in response to methyl jasmonate (MJ) and abscisic acid (ABA) treatment by using next-generation sequencing technology. Raw reads have been deposited to SRA database with the accession numbers, SRX2655642 and SRX2655643 (MJ-treated), SRXSRX2655644 and SRX2655645 (ABA-treated) and SRX2655646and SRX2655647 (Control).

Production of a carob enzymatic extract: potential use as a biofertilizer.

PubMed

Parrado, J; Bautista, J; Romero, E J; García-Martínez, A M; Friaza, V; Tejada, M

2008-05-01

In this paper, we describe a biological process that converts carob germ (CG), a proteinic vegetable by-product, into a water-soluble enzymatic hydrolyzate extract (CGHE). The chemical and physical properties are also described. The conversion is done using a proteolytic enzyme mixture. The main component of CGHE extracted by the enzymatic process is protein (68%), in the form of peptides and free amino acids, having a high content of glutamine and arginine, and a minor component of phytohormones, which are also extracted and solubilized from the CG. We have also compared its potential fertilizer/biostimulant capacity on growth, flowering, and fruiting of tomato plants (Licopericon pimpinellifolium cv. Momotaro) with that of an animal enzymatic protein hydrolyzate. CGHE had a significantly beneficial impact, most notably regarding the greater plant height, number of flowers per plant, and number of fruits per plant. This could be due primarily to its phytohormonal action.

[Recent advances in sample preparation methods of plant hormones].

PubMed

Wu, Qian; Wang, Lus; Wu, Dapeng; Duan, Chunfeng; Guan, Yafeng

2014-04-01

Plant hormones are a group of naturally occurring trace substances which play a crucial role in controlling the plant development, growth and environment response. With the development of the chromatography and mass spectroscopy technique, chromatographic analytical method has become a widely used way for plant hormone analysis. Among the steps of chromatographic analysis, sample preparation is undoubtedly the most vital one. Thus, a highly selective and efficient sample preparation method is critical for accurate identification and quantification of phytohormones. For the three major kinds of plant hormones including acidic plant hormones & basic plant hormones, brassinosteroids and plant polypeptides, the sample preparation methods are reviewed in sequence especially the recently developed methods. The review includes novel methods, devices, extractive materials and derivative reagents for sample preparation of phytohormones analysis. Especially, some related works of our group are included. At last, the future developments in this field are also prospected.

Water-Wisteria as an ideal plant to study heterophylly in higher aquatic plants.

PubMed

Li, Gaojie; Hu, Shiqi; Yang, Jingjing; Schultz, Elizabeth A; Clarke, Kurtis; Hou, Hongwei

2017-08-01

The semi-aquatic plant Water-Wisteria is suggested as a new model to study heterophylly due to its many advantages and typical leaf phenotypic plasticity in response to environmental factors and phytohormones. Water-Wisteria, Hygrophila difformis (Acanthaceae), is a fast growing semi-aquatic plant that exhibits a variety of leaf shapes, from simple leaves to highly branched compound leaves, depending on the environment. The phenomenon by which leaves change their morphology in response to environmental conditions is called heterophylly. In order to investigate the characteristics of heterophylly, we assessed the morphology and anatomy of Hygrophila difformis in different conditions. Subsequently, we verified that phytohormones and environmental factors can induce heterophylly and found that Hygrophila difformis is easily propagated vegetatively through either leaf cuttings or callus induction, and the callus can be easily transformed by Agrobacterium tumefaciens. These results suggested that Hygrophila difformis is a good model plant to study heterophylly in higher aquatic plants.

A Pivotal Role of DELLAs in Regulating Multiple Hormone Signals.

PubMed

Davière, Jean-Michel; Achard, Patrick

2016-01-04

Plant phenotypic plasticity is controlled by diverse hormone pathways, which integrate and convey information from multiple developmental and environmental signals. Moreover, in plants many processes such as growth, development, and defense are regulated in similar ways by multiple hormones. Among them, gibberellins (GAs) are phytohormones with pleiotropic actions, regulating various growth processes throughout the plant life cycle. Previous work has revealed extensive interplay between GAs and other hormones, but the molecular mechanism became apparent only recently. Molecular and physiological studies have demonstrated that DELLA proteins, considered as master negative regulators of GA signaling, integrate multiple hormone signaling pathways through physical interactions with transcription factors or regulatory proteins from different families. In this review, we summarize the latest progress in GA signaling and its direct crosstalk with the main phytohormone signaling, emphasizing the multifaceted role of DELLA proteins with key components of major hormone signaling pathways. Copyright © 2016 The Author. Published by Elsevier Inc. All rights reserved.

Elevated carbon dioxide increases salicylic acid in Glycine max.

PubMed

Casteel, Clare L; Segal, Lauren M; Niziolek, Olivia K; Berenbaum, May R; DeLucia, Evan H

2012-12-01

Concentrations of carbon dioxide (CO(2)) are increasing in the atmosphere, affecting soybean (Glycine max L.) phytohormone signaling and herbivore resistance. Whether the impact of elevated CO(2) on phytohormones and induced defenses is a generalized response within this species is an open question. We examined jasmonic acid (JA) and salicylic acid (SA) under ambient and elevated CO(2) concentrations with and without Japanese beetle (Popillia japonica Newman) damage and artificial damage across six soybean cultivars (HS93-4118, Pana, IA 3010, Loda, LN97-15076, and Dwight). Elevated CO(2) reduced constitutive levels of JA and related transcripts in some but not all soybean cultivars. In contrast to the variation in JA, constitutive levels of salicylic were increased universally among soybean cultivars grown under elevated CO(2). Variation in hormonal signaling may underpin observed variation in the response of insect herbivores and pathogens to plants grown under elevated CO(2).

Role of various hormones in photosynthetic responses of green plants under environmental stresses.

PubMed

Poonam; Bhardwaj, Renu; Kaur, Ravdeep; Bali, Shagun; Kaur, Parminder; Sirhindi, Geetika; Thukral, Ashwani K; Ohri, Puja; Vig, Adarsh P

2015-01-01

Environmental stress includes adverse factors like water deficit, high salinity, enhanced temperature and heavy metals etc. These stresses alter the normal growth and metabolic processes of plants including photosynthesis. Major photosynthetic responses under various stresses include inhibition of photosystems (I and II), changes in thylakoid complexes, decreased photosynthetic activity and modifications in structure and functions of chloroplasts etc. Various defense mechanisms are triggered inside the plants in response to these stresses that are regulated by plant hormones or plant growth regulators. These phytohormones include abscisic acid, auxins, cytokinins, ethylene, brassinosteroids, jasmonates and salicylic acid etc. The present review focuses on stress protective effects of plants hormones on the photosynthetic responses.

Mapping Local Cytosolic Enzymatic Activity in Human Esophageal Mucosa with Porous Silicon Nanoneedles.

PubMed

Chiappini, Ciro; Campagnolo, Paola; Almeida, Carina S; Abbassi-Ghadi, Nima; Chow, Lesley W; Hanna, George B; Stevens, Molly M

2015-09-16

Porous silicon nanoneedles can map Cathepsin B activity across normal and tumor human esophageal mucosa. Assembling a peptide-based Cathepsin B cleavable sensor over a large array of nano-needles allows the discrimination of cancer cells from healthy ones in mixed culture. The same sensor applied to tissue can map Cathepsin B activity with high resolution across the tumor margin area of esophageal adenocarcinoma. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

GeoMapApp Learning Activities: A Virtual Lab Environment for Student-Centred Engagement with Geoscience Data

NASA Astrophysics Data System (ADS)

Kluge, S.; Goodwillie, A. M.

2012-12-01

As STEM learning requirements enter the mainstream, there is benefit to providing the tools necessary for students to engage with research-quality geoscience data in a cutting-edge, easy-to-use map-based interface. Funded with an NSF GeoEd award, GeoMapApp Learning Activities ( http://serc.carleton.edu/geomapapp/collection.html ) are being created to help in that endeavour. GeoMapApp Learning Activities offer step-by-step instructions within a guided inquiry approach that enables students to dictate the pace of learning. Based upon GeoMapApp (http://www.geomapapp.org), a free, easy-to-use map-based data exploration and visualisation tool, each activity furnishes the educator with an efficient package of downloadable documents. This includes step-by-step student instructions and answer sheet; an educator's annotated worksheet containing teaching tips, additional content and suggestions for further work; and, quizzes for use before and after the activity to assess learning. Examples of activities so far created involve calculation and analysis of the rate of seafloor spreading; compilation of present-day evidence for huge ancient landslides on the seafloor around the Hawaiian islands; a study of radiometrically-dated volcanic rocks to help understand the concept of hotspots; and, the optimisation of contours as a means to aid visualisation of 3-D data sets on a computer screen. The activities are designed for students at the introductory undergraduate, community college and high school levels, and present a virtual lab-like environment to expose students to content and concepts typically found in those educational settings. The activities can be used in the classroom or out of class, and their guided nature means that the requirement for teacher intervention is reduced thus allowing students to spend more time analysing and understanding geoscience data, content and concepts. Each activity is freely available through the SERC-Carleton web site.

iTRAQ-Based Proteomic Analysis Reveals Potential Regulation Networks of IBA-Induced Adventitious Root Formation in Apple

PubMed Central

Lei, Chao; Fan, Sheng; Li, Ke; Meng, Yuan; Mao, Jiangping; Han, Mingyu; Zhao, Caiping; Bao, Lu; Zhang, Dong

2018-01-01

Adventitious root (AR) formation, which is controlled by endogenous and environmental factors, is indispensable for vegetative asexual propagation. However, comprehensive proteomic data on AR formation are still lacking. The aim of this work was to study indole-3-butyric acid (IBA)-induced AR formation in the dwarf apple rootstock ‘T337’. In this study, the effect of IBA on AR formation was analysed. Subsequent to treatment with IBA, both the rooting rate and root length of ‘T337’ increased significantly. An assessment of hormone levels in basal stem cuttings suggested that auxin, abscisic acid, and brassinolide were higher in basal stem cuttings that received the exogenous IBA application; while zeatin riboside, gibberellins, and jasmonic acid were lower than non-treated basal stem cuttings. To explore the underlying molecular mechanism, an isobaric tags for relative and absolute quantification (iTRAQ)-based proteomic technique was employed to identify the expression profiles of proteins at a key period of adventitious root induction (three days after IBA treatment). In total, 3355 differentially expressed proteins (DEPs) were identified. Many DEPs were closely related to carbohydrate metabolism and energy production, protein homeostasis, reactive oxygen and nitric oxide signaling, and cell wall remodeling biological processes; as well as the phytohormone signaling, which was the most critical process in response to IBA treatment. Further, RT-qPCR analysis was used to evaluate the expression level of nine genes that are involved in phytohormone signaling and their transcriptional levels were mostly in accordance with the protein patterns. Finally, a putative work model was proposed. Our study establishes a foundation for further research and sheds light on IBA-mediated AR formation in apple as well as other fruit rootstock cuttings. PMID:29495482

Comprehensive Transcriptome Analysis of Phytohormone Biosynthesis and Signaling Genes in the Flowers of Chinese Chinquapin (Castanea henryi).

PubMed

Fan, Xiaoming; Yuan, Deyi; Tian, Xiaoming; Zhu, Zhoujun; Liu, Meilan; Cao, Heping

2017-11-29

Chinese chinquapin (Castanea henryi) nut provides a rich source of starch and nutrients as food and feed, but its yield is restricted by a low ratio of female to male flowers. Little is known about the developmental programs underlying sex differentiation of the flowers. To investigate the involvement of phytohormones during sex differentiation, we described the morphology of male and female floral organs and the cytology of flower sex differentiation, analyzed endogenous levels of indole-3-acetic acid (IAA), gibberellins (GAs), cytokinins (CKs), and abscisic acid (ABA) in the flowers, investigated the effects of exogenous hormones on flower development, and evaluated the expression profiles of genes related to biosyntheses and signaling pathways of these four hormones using RNA-Seq combined with qPCR. Morphological results showed that the flowers consisted of unisexual and bisexual catkins, and could be divided into four developmental stages. HPLC results showed that CK accumulated much more in the female flowers than that in the male flowers, GA and ABA showed the opposite results, while IAA did not show a tendency. The effects of exogenous hormones on sex differentiation were consistent with those of endogenous hormones. RNA-Seq combined with qPCR analyses suggest that several genes may play key roles in hormone biosynthesis and sex differentiation. This study presents the first comprehensive report of phytohormone biosynthesis and signaling during sex differentiation of C. henryi, which should provide a foundation for further mechanistic studies of sex differentiation in Castanea Miller species and other nonmodel plants.

Exogenously applied spermidine alleviates photosynthetic inhibition under drought stress in maize (Zea mays L.) seedlings associated with changes in endogenous polyamines and phytohormones.

PubMed

Li, Lijie; Gu, Wanrong; Li, Jing; Li, Congfeng; Xie, Tenglong; Qu, Danyang; Meng, Yao; Li, Caifeng; Wei, Shi

2018-05-15

Drought stress (DS) is a major environmental factor limiting plant growth and crop productivity worldwide. It has been established that exogenous spermidine (Spd) stimulates plant tolerance to DS. The effects of exogenous Spd on plant growth, photosynthetic performance, and chloroplast ultrastructure as well as changes in endogenous polyamines (PAs) and phytohormones were investigate in DS-resistant (Xianyu 335) and DS-sensitive (Fenghe 1) maize seedlings under well-watered and DS treatments. Exogenous Spd alleviated the stress-induced reduction in growth, photosynthetic pigment content, photosynthesis rate (P n ) and photochemical quenching (q P ) parameters, including the maximum photochemistry efficiency of photosystem II (PSII) (F v /F m ), PSII operating efficiency (ФPSII), and qP coefficient. Exogenous Spd further enhanced stress-induced elevation in non-photochemical quenching (NPQ) and the de-epoxidation state of the xanthophyll cycle (DEPS). Microscopic analysis revealed that seedlings displayed a more ordered arrangement of chloroplast ultrastructure upon Spd application during DS. Exogenous Spd increased the endogenous PA concentrations in the stressed plants. Additionally, exogenous Spd increased indoleacetic acid (IAA), zeatin riboside (ZR) and gibberellin A 3 (GA 3 ) and decreased salicylic acid (SA) and jasmonate (JA) concentrations under DS. These results indicate that exogenous Spd can alleviate the growth inhibition and damage to the structure and function of the photosynthetic apparatus caused by DS and that this alleviation may be associated with changes in endogenous PAs and phytohormones. This study contributes to advances in the knowledge of Spd-induced drought tolerance. Copyright © 2018. Published by Elsevier Masson SAS.

Strigolactone Regulates Leaf Senescence in Concert with Ethylene in Arabidopsis.

PubMed

Ueda, Hiroaki; Kusaba, Makoto

2015-09-01

Leaf senescence is not a passive degenerative process; it represents a process of nutrient relocation, in which materials are salvaged for growth at a later stage or to produce the next generation. Leaf senescence is regulated by various factors, such as darkness, stress, aging, and phytohormones. Strigolactone is a recently identified phytohormone, and it has multiple functions in plant development, including repression of branching. Although strigolactone is implicated in the regulation of leaf senescence, little is known about its molecular mechanism of action. In this study, strigolactone biosynthesis mutant strains of Arabidopsis (Arabidopsis thaliana) showed a delayed senescence phenotype during dark incubation. The strigolactone biosynthesis genes MORE AXIALLY GROWTH3 (MAX3) and MAX4 were drastically induced during dark incubation and treatment with the senescence-promoting phytohormone ethylene, suggesting that strigolactone is synthesized in the leaf during leaf senescence. This hypothesis was confirmed by a grafting experiment using max4 as the stock and Columbia-0 as the scion, in which the leaves from the Columbia-0 scion senesced earlier than max4 stock leaves. Dark incubation induced the synthesis of ethylene independent of strigolactone. Strigolactone biosynthesis mutants showed a delayed senescence phenotype during ethylene treatment in the light. Furthermore, leaf senescence was strongly accelerated by the application of strigolactone in the presence of ethylene and not by strigolactone alone. These observations suggest that strigolactone promotes leaf senescence by enhancing the action of ethylene. Thus, dark-induced senescence is regulated by a two-step mechanism: induction of ethylene synthesis and consequent induction of strigolactone synthesis in the leaf. © 2015 American Society of Plant Biologists. All Rights Reserved.

The Impact of Concept Mapping on the Process of Problem-Based Learning

ERIC Educational Resources Information Center

Zwaal, Wichard; Otting, Hans

2012-01-01

A concept map is a graphical tool to activate and elaborate on prior knowledge, to support problem solving, promote conceptual thinking and understanding, and to organize and memorize knowledge. The aim of this study is to determine if the use of concept mapping (CM) in a problem-based learning (PBL) curriculum enhances the PBL process. The paper…

Geodesy- and geology-based slip-rate models for the Western United States (excluding California) national seismic hazard maps

USGS Publications Warehouse

Petersen, Mark D.; Zeng, Yuehua; Haller, Kathleen M.; McCaffrey, Robert; Hammond, William C.; Bird, Peter; Moschetti, Morgan; Shen, Zhengkang; Bormann, Jayne; Thatcher, Wayne

2014-01-01

The 2014 National Seismic Hazard Maps for the conterminous United States incorporate additional uncertainty in fault slip-rate parameter that controls the earthquake-activity rates than was applied in previous versions of the hazard maps. This additional uncertainty is accounted for by new geodesy- and geology-based slip-rate models for the Western United States. Models that were considered include an updated geologic model based on expert opinion and four combined inversion models informed by both geologic and geodetic input. The two block models considered indicate significantly higher slip rates than the expert opinion and the two fault-based combined inversion models. For the hazard maps, we apply 20 percent weight with equal weighting for the two fault-based models. Off-fault geodetic-based models were not considered in this version of the maps. Resulting changes to the hazard maps are generally less than 0.05 g (acceleration of gravity). Future research will improve the maps and interpret differences between the new models.

Comprehensive analysis of mitogen-activated protein kinase cascades in chrysanthemum

PubMed Central

Ding, Lian; Zhang, Xue; Li, Peiling; Liu, Ye

2018-01-01

Background Mitogen-activated protein kinase (MAPK) cascades, an important type of pathway in eukaryotic signaling networks, play a key role in plant defense responses, growth and development. Methods Phylogenetic analysis and conserved motif analysis of the MKK and MPK families in Arabidopsis thaliana, Helianthus annuus and Chrysanthemum morifolium classified MKK genes and MPK genes. qRT-PCR was used for the expression patterns of CmMPK and CmMKK genes, and yeast two-hybrid assay was applied to clear the interaction between CmMPKs and CmMKKs. Results We characterized six MKK genes and 11 MPK genes in chrysanthemum based on transcriptomic sequences and classified these genes into four groups. qRT-PCR analysis demonstrated that CmMKKs and CmMPKs exhibited various expression patterns in different organs of chrysanthemum and in response to abiotic stresses and phytohormone treatments. Furthermore, a yeast two-hybrid assay was applied to analyze the interaction between CmMKKs and CmMPKs and reveal the MAPK cascades in chrysanthemum. Discussion Our data led us to propose that CmMKK4-CmMPK13 and CmMKK2-CmMPK4 may be involved in regulating salt resistance and in the relationship between CmMKK9 and CmMPK6 and temperature stress. PMID:29942696

INTER-REGULATION OF THE UNFOLDED PROTEIN RESPONSE AND AUXIN SIGNALING

PubMed Central

Chen, Yani; Aung, Kyaw; Rolčík, Jakub; Walicki, Kathryn; Friml, Jiří; Brandizzi, Federica

2013-01-01

SUMMARY The unfolded protein response (UPR) is a signaling network triggered by overload of protein-folding demand in the endoplasmic reticulum (ER), a condition termed ER stress. The UPR is critical for growth and development; nonetheless, connections between the UPR and other cellular regulatory processes remain largely unknown. Here, we identify a link between the UPR and the phytohormone auxin, a master regulator of plant physiology. We show that ER stress triggers down-regulation of auxin sensors and transporters in Arabidopsis thaliana. We also demonstrate that an Arabidopsis mutant of a conserved ER stress sensor IRE1 exhibits defects in the auxin response and levels. These data not only support that the plant IRE1 is required for auxin homeostasis, they also reveal a species-specific feature of IRE1 in multicellular eukaryotes. Furthermore, by establishing that UPR activation is reduced in mutants of ER-localized auxin transporters, including PIN5, we define a long-neglected biological significance of ER-based auxin regulation. We further examine the functional relationship of IRE1 and PIN5 by showing that an ire1 pin5 triple mutant enhances defects of UPR activation and auxin homeostasis in ire1 or pin5. Our results imply that the plant UPR has evolved a hormone-dependent strategy for coordinating ER function with physiological processes. PMID:24180465

Pavement cells: a model system for non-transcriptional auxin signalling and crosstalks

PubMed Central

Chen, Jisheng; Wang, Fei; Zheng, Shiqin; Xu, Tongda; Yang, Zhenbiao

2015-01-01

Auxin (indole acetic acid) is a multifunctional phytohormone controlling various developmental patterns, morphogenetic processes, and growth behaviours in plants. The transcription-based pathway activated by the nuclear TRANSPORT INHIBITOR RESISTANT 1/auxin-related F-box auxin receptors is well established, but the long-sought molecular mechanisms of non-transcriptional auxin signalling remained enigmatic until very recently. Along with the establishment of the Arabidopsis leaf epidermal pavement cell (PC) as an exciting and amenable model system in the past decade, we began to gain insight into non-transcriptional auxin signalling. The puzzle-piece shape of PCs forms from intercalated or interdigitated cell growth, requiring local intra- and inter-cellular coordination of lobe and indent formation. Precise coordination of this interdigitated pattern requires auxin and an extracellular auxin sensing system that activates plasma membrane-associated Rho GTPases from plants and subsequent downstream events regulating cytoskeletal reorganization and PIN polarization. Apart from auxin, mechanical stress and cytokinin have been shown to affect PC interdigitation, possibly by interacting with auxin signals. This review focuses upon signalling mechanisms for cell polarity formation in PCs, with an emphasis on non-transcriptional auxin signalling in polarized cell expansion and pattern formation and how different auxin pathways interplay with each other and with other signals. PMID:26047974

Competition between isoprene emission and pigment synthesis during leaf development in aspen

PubMed Central

Rasulov, Bahtijor; Bichele, Irina; Laisk, Agu; Niinemets, Ülo

2014-01-01

In growing leaves, lack of isoprene synthase is considered responsible for delayed isoprene emission, but competition for dimethylallyl diphosphate (DMADP), the substrate for both isoprene synthesis and prenyltransferase reactions in photosynthetic pigment and phytohormone synthesis, can also play a role. We used a kinetic approach based on postillumination isoprene decay and modeling DMADP consumption to estimate in vivo kinetic characteristics of isoprene synthase and prenyltransferase reactions, and determine the share of DMADP use by different processes through leaf development in Populus tremula. Pigment synthesis rate was also estimated from pigment accumulation data, and distribution of DMADP use from isoprene emission changes due to alendronate, a selective inhibitor of prenyltransferases. Development of photosynthetic activity and pigment synthesis occurred with the greatest rate in 1-5 days old leaves when isoprene emission was absent. Isoprene emission commenced on days 5-6 and increased simultaneously with slowing down of pigment synthesis. In vivo Michaelis-Menten constant (Km) values obtained were 265 nmol m−2 (20 μM) for DMADP-consuming prenyltransferase reactions and 2560 nmol m−2 (190 μM) for isoprene synthase. Thus, despite decelerating pigment synthesis reactions in maturing leaves, isoprene emission in young leaves was limited by both isoprene synthase activity and competition for DMADP by prenyltransferase reactions. PMID:24033429

Systemic acquired tolerance to virulent bacterial pathogens in tomato.

PubMed

Block, Anna; Schmelz, Eric; O'Donnell, Phillip J; Jones, Jeffrey B; Klee, Harry J

2005-07-01

Recent studies on the interactions between plants and pathogenic microorganisms indicate that the processes of disease symptom development and pathogen growth can be uncoupled. Thus, in many instances, the symptoms associated with disease represent an active host response to the presence of a pathogen. These host responses are frequently mediated by phytohormones. For example, ethylene and salicylic acid (SA) mediate symptom development but do not influence bacterial growth in the interaction between tomato (Lycopersicon esculentum) and virulent Xanthomonas campestris pv vesicatoria (Xcv). It is not apparent why extensive tissue death is integral to a defense response if it does not have the effect of limiting pathogen proliferation. One possible function for this hormone-mediated response is to induce a systemic defense response. We therefore assessed the systemic responses of tomato to Xcv. SA- and ethylene-deficient transgenic lines were used to investigate the roles of these phytohormones in systemic signaling. Virulent and avirulent Xcv did induce a systemic response as evidenced by expression of defense-associated pathogenesis-related genes in an ethylene- and SA-dependent manner. This systemic response reduced cell death but not bacterial growth during subsequent challenge with virulent Xcv. This systemic acquired tolerance (SAT) consists of reduced tissue damage in response to secondary challenge with a virulent pathogen with no effect upon pathogen growth. SAT was associated with a rapid ethylene and pathogenesis-related gene induction upon challenge. SAT was also induced by infection with Pseudomonas syringae pv tomato. These data show that SAT resembles systemic acquired resistance without inhibition of pathogen growth.

Green Map Exercises as an Avenue for Problem-Based Learning in a Data-Rich Environment

ERIC Educational Resources Information Center

Tulloch, David; Graff, Elizabeth

2007-01-01

This article describes a series of data-based Green Map learning exercises positioned within a problem-based framework and examines the appropriateness of projects like these as a form of geography education. Problem-based learning (PBL) is an educational technique that engages students in learning through activities that require creative problem…

All-optical mapping of barrel cortex circuits based on simultaneous voltage-sensitive dye imaging and channelrhodopsin-mediated photostimulation

PubMed Central

Lo, Shun Qiang; Koh, Dawn X. P.; Sng, Judy C. G.; Augustine, George J.

2015-01-01

Abstract. We describe an experimental approach that uses light to both control and detect neuronal activity in mouse barrel cortex slices: blue light patterned by a digital micromirror array system allowed us to photostimulate specific layers and columns, while a red-shifted voltage-sensitive dye was used to map out large-scale circuit activity. We demonstrate that such all-optical mapping can interrogate various circuits in somatosensory cortex by sequentially activating different layers and columns. Further, mapping in slices from whisker-deprived mice demonstrated that chronic sensory deprivation did not significantly alter feedforward inhibition driven by layer 5 pyramidal neurons. Further development of voltage-sensitive optical probes should allow this all-optical mapping approach to become an important and high-throughput tool for mapping circuit interactions in the brain. PMID:26158003

Metabolomics analysis reveals 6-benzylaminopurine as a stimulator for improving lipid and DHA accumulation of Aurantiochytriumsp.

PubMed

Yu, Xin-Jun; Sun, Jie; Zheng, Jian-Yong; Sun, Ya-Qi; Wang, Zhao

2016-04-01

Phytohormones are chemical messengers that have a positive effect on biodiesel production of microalgae at low concentrations. However, the effect of phytohormone 6-benzylaminopurine on lipid and docosahexaenoic acid (DHA) production in marine DHA-producer Aurantiochytrium has never been reported. In this study, a GC-MS-based metabolomics method combined with a multivariate analysis is applied to reveal the metabolic mechanism of 6-benzylaminopurine enhancing production of lipid and DHA in Aurantiochytrium sp.YLH70. In total, 71 metabolites were identified by GC-MS. The PCA model revealed that 76.9% of metabolite variation was related to 6-benzylaminopurine treatment, and overall metabolomics profiles between the 6-benzylaminopurine and control groups were clearly discriminated. Forty-six metabolites identified by the PLS-DA model were responsible for responding to 6-benzylaminopurine. Metabolic analysis showed that 6-benzylaminopurine could accelerate the rate of utilization of glucose in Aurantiochytrium sp. YLH70, and the metabolic flux from glycolysis, TCA cycle and mevalonate pathway to fatty acids biosynthesis was promoted. Moreover, the anti-stress mechanism in Aurantiochytrium sp.YLH70 might be induced by 6-benzylaminopurine. Metabolomics is a suitable tool to discover the metabolic mechanism for improving lipid and DHA accumulation in a microorganism. 6-benzylaminopurine has the potential to stimulate lipid and DHA production of Aurantiochytrium sp.YLH70 for industrial purposes. © 2015 The Authors. Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Genome-wide analysis of carotenoid cleavage oxygenase genes and their responses to various phytohormones and abiotic stresses in apple (Malus domestica).

PubMed

Chen, Hongfei; Zuo, Xiya; Shao, Hongxia; Fan, Sheng; Ma, Juanjuan; Zhang, Dong; Zhao, Caiping; Yan, Xiangyan; Liu, Xiaojie; Han, Mingyu

2018-02-01

Carotenoid cleavage oxygenases (CCOs) are able to cleave carotenoids to produce apocarotenoids and their derivatives, which are important for plant growth and development. In this study, 21 apple CCO genes were identified and divided into six groups based on their phylogenetic relationships. We further characterized the apple CCO genes in terms of chromosomal distribution, structure and the presence of cis-elements in the promoter. We also predicted the cellular localization of the encoded proteins. An analysis of the synteny within the apple genome revealed that tandem, segmental, and whole-genome duplication events likely contributed to the expansion of the apple carotenoid oxygenase gene family. An additional integrated synteny analysis identified orthologous carotenoid oxygenase genes between apple and Arabidopsis thaliana, which served as references for the functional analysis of the apple CCO genes. The net photosynthetic rate, transpiration rate, and stomatal conductance of leaves decreased, while leaf stomatal density increased under drought and saline conditions. Tissue-specific gene expression analyses revealed diverse spatiotemporal expression patterns. Finally, hormone and abiotic stress treatments indicated that many apple CCO genes are responsive to various phytohormones as well as drought and salinity stresses. The genome-wide identification of apple CCO genes and the analyses of their expression patterns described herein may provide a solid foundation for future studies examining the regulation and functions of this gene family. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Genome-wide investigation and expression profiling of APX gene family in Gossypium hirsutum provide new insights in redox homeostasis maintenance during different fiber development stages.

PubMed

Tao, Chengcheng; Jin, Xiang; Zhu, Liping; Xie, Quanliang; Wang, Xuchu; Li, Hongbin

2018-06-01

Ascorbate peroxidase (APX) is a member of heme-containing peroxidases which catalyze the H 2 O 2 -dependent oxidation of a wide range of substrates in plants and animals. As is known, H 2 O 2 acts as a signaling molecule in the regulation of fiber development. Our previous work reported that ascorbate peroxidase 1 (GhAPX1) was important for cotton fiber elongation. However, knowledge about APX gene family members and their evolutionary and functional characteristics in cotton is limited. Here, we report 26 GhAPX genes by genome-wide investigation of tetraploid cotton Gossypium hirsutum. Phylogenetic and gene structure analyses classified these APX members into five clades and syntenic analysis suggested two duplication events. Expression profiling of the 26 APXs revealed that ten members are expressed in cotton fibers. Notably, GhAPX10A, GhAPX10D, GhAPX12A, and GhAPX12D showed high expression levels in 30-day fiber, while GhAPX1A/D, GhAPX3A/D, and GhAPX6A/D showed very low expression levels. The enzyme activity and H 2 O 2 content assays revealed that cotton fiber kept high enzyme activity and the lowest H 2 O 2 level in 30-day fibers, indicating that other than GhAPX1, the newly reported APX members are responsible for the reactive oxygen species homeostasis in the cotton fiber maturation stages. Expression profiling of ten fiber-expressed APXs after phytohormone treatments revealed their regulation patterns by different stimuli, suggesting that GhAPX1, GhAPX12A, and GhAPX12D are responsible to most phytohormone treatments. Our data provided evolutionary and functional information of GhAPX gene family members and revealed that different members are responsible to redox homeostasis during different cotton fiber development stages.

Effects of a Question Prompt-Based Concept Mapping Approach on Students' Learning Achievements, Attitudes and 5C Competences in Project-Based Computer Course Activities

ERIC Educational Resources Information Center

Wang, Hsiu-Ying; Huang, Iwen; Hwang, Gwo-Jen

2016-01-01

Concept mapping has been widely used in various fields to facilitate students' organization of knowledge. Previous studies have, however, pointed out that it is difficult for students to construct concept maps from the abundant searched data without appropriate scaffolding. Thus, researchers have suggested that students could produce high quality…

GeoInquiries: Addressing a Grand Challenge for Teaching with GIS in Schools

NASA Astrophysics Data System (ADS)

DiBiase, D.; Baker, T.

2016-12-01

According to the National Research Council (2006), geographic information systems (GIS) is a powerful tool for expanding students' abilities to think spatially, a critical skill for future STEM professionals. However, educators in mainstream subjects in U.S. education have struggled for decades to use GIS effectively in classrooms. GeoInquiries are no cost, standards-based (NGSS or AP), Creative Commons-licensed instructional activities that guide inquiry around map-based concepts found in key subjects like Earth and environmental science. Web maps developed for GeoInquiries expand upon printed maps in leading textbooks by taking advantage of 21st GIS capabilities. GeoInquiry collections consist of 15 activities, each chosen to offer a map-based activity every few weeks throughout the school year. GeoInquiries use a common inquiry instructional framework, learned by many educators during their teacher preparation coursework. GeoInquiries are instructionally flexible - acting as much like building blocks for crafting custom activities as finished instructional materials. Over a half million geoinquiries will be accessed in the next twelve months - serving an anticipated 15 million students. After a generation of outreach to the educators, GIS is finally finding its way the mainstream.

Combining task-evoked and spontaneous activity to improve pre-operative brain mapping with fMRI

PubMed Central

Fox, Michael D.; Qian, Tianyi; Madsen, Joseph R.; Wang, Danhong; Li, Meiling; Ge, Manling; Zuo, Huan-cong; Groppe, David M.; Mehta, Ashesh D.; Hong, Bo; Liu, Hesheng

2016-01-01

Noninvasive localization of brain function is used to understand and treat neurological disease, exemplified by pre-operative fMRI mapping prior to neurosurgical intervention. The principal approach for generating these maps relies on brain responses evoked by a task and, despite known limitations, has dominated clinical practice for over 20 years. Recently, pre-operative fMRI mapping based on correlations in spontaneous brain activity has been demonstrated, however this approach has its own limitations and has not seen widespread clinical use. Here we show that spontaneous and task-based mapping can be performed together using the same pre-operative fMRI data, provide complimentary information relevant for functional localization, and can be combined to improve identification of eloquent motor cortex. Accuracy, sensitivity, and specificity of our approach are quantified through comparison with electrical cortical stimulation mapping in eight patients with intractable epilepsy. Broad applicability and reproducibility of our approach is demonstrated through prospective replication in an independent dataset of six patients from a different center. In both cohorts and every individual patient, we see a significant improvement in signal to noise and mapping accuracy independent of threshold, quantified using receiver operating characteristic curves. Collectively, our results suggest that modifying the processing of fMRI data to incorporate both task-based and spontaneous activity significantly improves functional localization in pre-operative patients. Because this method requires no additional scan time or modification to conventional pre-operative data acquisition protocols it could have widespread utility. PMID:26408860

High-resolution mapping of the triangle of Koch: Spatial heterogeneity of fast pathway atrionodal connections.

PubMed

Chua, Kelvin; Upadhyay, Gaurav A; Lee, Elliot; Aziz, Zaid; Beaser, Andrew D; Ozcan, Cevher; Broman, Michael; Nayak, Hemal M; Tung, Roderick

2018-03-01

Dedicated mapping studies of the triangle of Koch to characterize retrograde fast pathway activation have not been previously performed using high-resolution, 3-dimensional, multielectrode mapping technology. To delineate the activation pattern and spatial distribution of the retrograde fast pathway within the triangle of Koch during typical atrioventricular nodal reentrant tachycardia (AVNRT) and right ventricular pacing in a consecutive series of patients using the Rhythmia mapping system (Boston Scientific, Natick, MA). A total of 18 patients with symptomatic typical AVNRT referred for ablation underwent ultra high-density mapping of atrial activation with minielectrode basket configuration during tachycardia. The earliest atrial activation was mapped using automated annotation, with manual overreading by 2 independent observers. The triangle of Koch was classified into 3 anatomic regions: anteroseptal (His), midseptal, and posteroseptal (coronary sinus roof). Thirteen patients underwent mapping of atrial activation during ventricular pacing. A median of 422 mapping points (interquartile range 258-896 points) was acquired within the triangle of Koch during tachycardia. The most common site of earliest atrial activation within the triangle of Koch was anterior in 67% of patients (n = 12). Midseptal early atrial activation was seen in 17% (n = 3), and posteroseptal activation was observed in 11% (n = 2). One patient exhibited broad simultaneous activation of the entire triangle of Koch. Slow pathway potentials were not identified. With high-resolution multielectrode mapping, atrial activation during typical AVNRT exhibited anatomic variability and spatially heterogeneous activation within the triangle of Koch. These findings highlight the limitations of an anatomically based classification of atrioventricular nodal retrograde pathways. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Mathemagenic Activities Program: [Reports on Cognitive/Language Development].

ERIC Educational Resources Information Center

Smock, Charles D., Ed.

This set of 13 research reports, bulletins and papers is a product of the Mathemagenic Activities Program (MAP) for early childhood education of the University of Georgia Follow Through Program. Based on Piagetian theory, the MAP provides sequentially structured sets of curriculum materials and processes that are designed to continually challenge…

Correlation between resting state fMRI total neuronal activity and PET metabolism in healthy controls and patients with disorders of consciousness.

PubMed

Soddu, Andrea; Gómez, Francisco; Heine, Lizette; Di Perri, Carol; Bahri, Mohamed Ali; Voss, Henning U; Bruno, Marie-Aurélie; Vanhaudenhuyse, Audrey; Phillips, Christophe; Demertzi, Athena; Chatelle, Camille; Schrouff, Jessica; Thibaut, Aurore; Charland-Verville, Vanessa; Noirhomme, Quentin; Salmon, Eric; Tshibanda, Jean-Flory Luaba; Schiff, Nicholas D; Laureys, Steven

2016-01-01

The mildly invasive 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is a well-established imaging technique to measure 'resting state' cerebral metabolism. This technique made it possible to assess changes in metabolic activity in clinical applications, such as the study of severe brain injury and disorders of consciousness. We assessed the possibility of creating functional MRI activity maps, which could estimate the relative levels of activity in FDG-PET cerebral metabolic maps. If no metabolic absolute measures can be extracted, our approach may still be of clinical use in centers without access to FDG-PET. It also overcomes the problem of recognizing individual networks of independent component selection in functional magnetic resonance imaging (fMRI) resting state analysis. We extracted resting state fMRI functional connectivity maps using independent component analysis and combined only components of neuronal origin. To assess neuronality of components a classification based on support vector machine (SVM) was used. We compared the generated maps with the FDG-PET maps in 16 healthy controls, 11 vegetative state/unresponsive wakefulness syndrome patients and four locked-in patients. The results show a significant similarity with ρ = 0.75 ± 0.05 for healthy controls and ρ = 0.58 ± 0.09 for vegetative state/unresponsive wakefulness syndrome patients between the FDG-PET and the fMRI based maps. FDG-PET, fMRI neuronal maps, and the conjunction analysis show decreases in frontoparietal and medial regions in vegetative patients with respect to controls. Subsequent analysis in locked-in syndrome patients produced also consistent maps with healthy controls. The constructed resting state fMRI functional connectivity map points toward the possibility for fMRI resting state to estimate relative levels of activity in a metabolic map.

ZIFL1.1 transporter modulates polar auxin transport by stabilizing membrane abundance of multiple PINs in Arabidopsis root tip

PubMed Central

Remy, Estelle; Baster, Pawel; Friml, Jiří; Duque, Paula

2013-01-01

Cell-to-cell directional flow of the phytohormone auxin is primarily established by polar localization of the PIN auxin transporters, a process tightly regulated at multiple levels by auxin itself. We recently reported that, in the context of strong auxin flows, activity of the vacuolar ZIFL1.1 transporter is required for fine-tuning of polar auxin transport rates in the Arabidopsis root. In particular, ZIFL1.1 function protects plasma-membrane stability of the PIN2 carrier in epidermal root tip cells under conditions normally triggering PIN2 degradation. Here, we show that ZIFL1.1 activity at the root tip also promotes PIN1 plasma-membrane abundance in central cylinder cells, thus supporting the notion that ZIFL1.1 acts as a general positive modulator of polar auxin transport in roots. PMID:23857365

Analysis of defense signals in Arabidopsis thaliana leaves by ultra-performance liquid chromatography/tandem mass spectrometry: jasmonates, salicylic acid, abscisic acid.

PubMed

Stingl, Nadja; Krischke, Markus; Fekete, Agnes; Mueller, Martin J

2013-01-01

Defense signaling compounds and phytohormones play an essential role in the regulation of plant responses to various environmental abiotic and biotic stresses. Among the most severe stresses are herbivory, pathogen infection, and drought stress. The major hormones involved in the regulation of these responses are 12-oxo-phytodienoic acid (OPDA), the pro-hormone jasmonic acid (JA) and its biologically active isoleucine conjugate (JA-Ile), salicylic acid (SA), and abscisic acid (ABA). These signaling compounds are present and biologically active at very low concentrations from ng/g to μg/g dry weight. Accurate and sensitive quantification of these signals has made a significant contribution to the understanding of plant stress responses. Ultra-performance liquid chromatography (UPLC) coupled with a tandem quadrupole mass spectrometer (MS/MS) has become an essential technique for the analysis and quantification of these compounds.

Topographical memory for newly-learned maps is differentially affected by route-based versus landmark-based learning: a functional MRI study.

PubMed

Beatty, Erin L; Muller-Gass, Alexandra; Wojtarowicz, Dorothy; Jobidon, Marie-Eve; Smith, Ingrid; Lam, Quan; Vartanian, Oshin

2018-04-11

Humans rely on topographical memory to encode information about spatial aspects of environments. However, even though people adopt different strategies when learning new maps, little is known about the impact of those strategies on topographical memory, and their neural correlates. To examine that issue, we presented participants with 40 unfamiliar maps, each of which displayed one major route and three landmarks. Half were instructed to memorize the maps by focusing on the route, whereas the other half memorized the maps by focusing on the landmarks. One day later, the participants were tested on their ability to distinguish previously studied 'old' maps from completely unfamiliar 'new' maps under conditions of high and low working memory load in the functional MRI scanner. Viewing old versus new maps was associated with relatively greater activation in a distributed set of regions including bilateral inferior temporal gyrus - an important region for recognizing visual objects. Critically, whereas the performance of participants who had followed a route-based strategy dropped to chance level under high working memory load, participants who had followed a landmark-based strategy performed at above chance levels under both high and low working memory load - reflected by relatively greater activation in the left inferior parietal lobule (i.e. rostral part of the supramarginal gyrus known as area PFt). Our findings suggest that landmark-based learning may buffer against the effects of working memory load during recognition, and that this effect is represented by the greater involvement of a brain region implicated in both topographical and working memory.

Impact of a community-based prevention marketing intervention to promote physical activity among middle-aged women.

PubMed

Sharpe, Patricia A; Burroughs, Ericka L; Granner, Michelle L; Wilcox, Sara; Hutto, Brent E; Bryant, Carol A; Peck, Lara; Pekuri, Linda

2010-06-01

A physical activity intervention applied principles of community-based participatory research, the community-based prevention marketing framework, and social cognitive theory. A nonrandomized design included women ages 35 to 54 in the southeastern United States. Women (n = 430 preprogram, n = 217 postprogram) enrolled in a 24-week behavioral intervention and were exposed to a media campaign. They were compared to cross-sectional survey samples at pre- (n = 245) and postprogram (n = 820) from the media exposed county and a no-intervention county (n = 234 pre, n = 822 post). Women in the behavioral intervention had statistically significant positive changes on physical activity minutes, walking, park and trail use, knowledge of mapped routes and exercise partner, and negative change on exercise self-efficacy. Media exposed women had statistically significant pre- to postprogram differences on knowledge of mapped routes. No-intervention women had significant pre- to postprogram differences on physical activity minutes, walking, and knowledge of mapped routes.

Current trends in satellite based emergency mapping - the need for harmonisation

NASA Astrophysics Data System (ADS)

Voigt, Stefan

2013-04-01

During the past years, the availability and use of satellite image data to support disaster management and humanitarian relief organisations has largely increased. The automation and data processing techniques are greatly improving as well as the capacity in accessing and processing satellite imagery in getting better globally. More and more global activities via the internet and through global organisations like the United Nations or the International Charter Space and Major Disaster engage in the topic, while at the same time, more and more national or local centres engage rapid mapping operations and activities. In order to make even more effective use of this very positive increase of capacity, for the sake of operational provision of analysis results, for fast validation of satellite derived damage assessments, for better cooperation in the joint inter agency generation of rapid mapping products and for general scientific use, rapid mapping results in general need to be better harmonized, if not even standardized. In this presentation, experiences from various years of rapid mapping gained by the DLR Center for satellite based Crisis Information (ZKI) within the context of the national activities, the International Charter Space and Major Disasters, GMES/Copernicus etc. are reported. Furthermore, an overview on how automation, quality assurance and optimization can be achieved through standard operation procedures within a rapid mapping workflow is given. Building on this long term rapid mapping experience, and building on the DLR initiative to set in pace an "International Working Group on Satellite Based Emergency Mapping" current trends in rapid mapping are discussed and thoughts on how the sharing of rapid mapping information can be optimized by harmonizing analysis results and data structures are presented. Such an harmonization of analysis procedures, nomenclatures and representations of data as well as meta data are the basis to better cooperate within the global rapid mapping community throughout local/national, regional/supranational and global scales

Solar flare predictions and warnings

NASA Technical Reports Server (NTRS)

White, K. P., III; Mayfield, E. B.

1973-01-01

The real-time solar monitoring information supplied to support SPARCS-equipped rocket launches, the routine collection and analysis of 3.3-mm solar radio maps, short-term flare forecasts based on these maps, longer-term forecasts based on the recurrence of active regions, and results of the synoptic study of solar active regions at 3.3-mm wavelength are presented. Forecasted flares in the 24-hour forecasts were 81% accurate, and those in the 28-day forecasts were 97% accurate. Synoptic radio maps at 3.3-mm wavelength are presented for twenty-three solar rotations in 1967 and 1968, as well as synoptic flare charts for the same period.

Recently active traces of the Bartlett Springs Fault, California: a digital database

USGS Publications Warehouse

Lienkaemper, James J.

2010-01-01

The purpose of this map is to show the location of and evidence for recent movement on active fault traces within the Bartlett Springs Fault Zone, California. The location and recency of the mapped traces is primarily based on geomorphic expression of the fault as interpreted from large-scale aerial photography. In a few places, evidence of fault creep and offset Holocene strata in trenches and natural exposures have confirmed the activity of some of these traces. This publication is formatted both as a digital database for use within a geographic information system (GIS) and for broader public access as map images that may be browsed on-line or download a summary map. The report text describes the types of scientific observations used to make the map, gives references pertaining to the fault and the evidence of faulting, and provides guidance for use of and limitations of the map.

CortiQ-based Real-Time Functional Mapping for Epilepsy Surgery.

PubMed

Kapeller, Christoph; Korostenskaja, Milena; Prueckl, Robert; Chen, Po-Ching; Lee, Ki Heyeong; Westerveld, Michael; Salinas, Christine M; Cook, Jane C; Baumgartner, James E; Guger, Christoph

2015-06-01

To evaluate the use of the cortiQ-based mapping system (g.tec medication engineering GmbH, Austria) for real-time functional mapping (RTFM) and to compare it to results from electrical cortical stimulation mapping (ESM) and functional magnetic resonance imaging (fMRI). Electrocorticographic activity was recorded in 3 male patients with intractable epilepsy by using cortiQ mapping system and analyzed in real time. Activation related to motor, sensory, and receptive language tasks was determined by evaluating the power of the high gamma frequency band (60-170 Hz). The sensitivity and specificity of RTFM were tested against ESM and fMRI results. "Next-neighbor" approach demonstrated [sensitivity/specificity %] (1) RTFM against ESM: 100.00/79.70 for hand motor; 100.00/73.87 for hand sensory; -/87 for language (it was not identified by the ESM); (2) RTFM against fMRI: 100.00/84.4 for hand motor; 66.70/85.35 for hand sensory; and 87.85/77.70 for language. The results of the quantitative "next-neighbor" RTFM evaluation were concordant to those from ESM and fMRI. The RTFM correlates well with localization of hand motor function provided by ESM and fMRI, which may offer added localization in the operating room and guidance for extraoperative ESM mapping. Real-time functional mapping correlates with fMRI language activation when ESM findings are negative. It has fewer limitations than ESM and greater flexibility in activation paradigms and measuring responses.

Overexpression of the Novel Arabidopsis Gene At5g02890 Alters Inflorescence Stem Wax Composition and Affects Phytohormone Homeostasis

PubMed Central

Xu, Liping; Zeisler, Viktoria; Schreiber, Lukas; Gao, Jie; Hu, Kaining; Wen, Jing; Yi, Bin; Shen, Jinxiong; Ma, Chaozhi; Tu, Jinxing; Fu, Tingdong

2017-01-01

The cuticle is composed of cutin and cuticular wax. It covers the surfaces of land plants and protects them against environmental damage. At5g02890 encodes a novel protein in Arabidopsis thaliana. In the current study, protein sequence analysis showed that At5g02890 is highly conserved in the Brassicaceae. Arabidopsis lines overexpressing At5g02890 (OE-At5g02890 lines) and an At5g02890 orthologous gene from Brassica napus (OE-Bn1 lines) exhibited glossy stems. Chemical analysis revealed that overexpression of At5g02890 caused significant reductions in the levels of wax components longer than 28 carbons (C28) in inflorescence stems, whereas the levels of wax molecules of chain length C28 or shorter were significantly increased. Transcriptome analysis indicated that nine of 11 cuticular wax synthesis-related genes with different expression levels in OE-At5g02890 plants are involved in very-long-chain fatty acid (VLCFA) elongation. At5g02890 is localized to the endoplasmic reticulum (ER), which is consistent with its function in cuticular wax biosynthesis. These results demonstrate that the overexpression of At5g02890 alters cuticular wax composition by partially blocking VLCFA elongation of C28 and higher. In addition, detailed analysis of differentially expressed genes associated with plant hormones and endogenous phytohormone levels in wild-type and OE-At5g02890 plants indicated that abscisic acid (ABA), jasmonic acid (JA), and jasmonoyl-isoleucine (JA-Ile) biosynthesis, as well as polar auxin transport, were also affected by overexpression of At5g02890. Taken together, these findings indicate that overexpression of At5g02890 affects both cuticular wax biosynthesis and phytohormone homeostasis in Arabidopsis. PMID:28184233

Gibberellins Producing Endophytic Fungus Porostereum spadiceum AGH786 Rescues Growth of Salt Affected Soybean

PubMed Central

Hamayun, Muhammad; Hussain, Anwar; Khan, Sumera A.; Kim, Ho-Youn; Khan, Abdul L.; Waqas, Muhammad; Irshad, Muhammad; Iqbal, Amjad; Rehman, Gauhar; Jan, Samin; Lee, In-Jung

2017-01-01

In the pursuit of sustainable agriculture through environment and human health friendly practices, we evaluated the potential of a novel gibberellins (GAs) producing basidiomycetous endophytic fungus Porostereum spadiceum AGH786, for alleviating salt stress and promoting health benefits of soybean. Soybean seedlings exposed to different levels of NaCl stress (70 and 140 mM) under greenhouse conditions, were inoculated with the AGH786 strain. Levels of phytohormones including GAs, JA and ABA, and isoflavones were compared in control and the inoculated seedlings to understand the mechanism through which the stress is alleviated. Gibberellins producing endophytic fungi have been vital for promoting plant growth under normal and stress conditions. We report P. spadiceum AGH786 as the ever first GAs producing basidiomycetous fungus capable of producing six types of GAs. In comparison to the so for most efficient GAs producing Gibberella fujikuroi, AGH786 produced significantly higher amount of the bioactive GA3. Salt-stressed phenotype of soybean seedlings was characterized by low content of GAs and high amount of ABA and JA with reduced shoot length, biomass, leaf area, chlorophyll contents, and rate of photosynthesis. Mitigation of salt stress by AGH786 was always accompanied by high GAs, and low ABA and JA, suggesting that this endophytic fungus reduces the effect of salinity by modulating endogenous phytohormones of the seedlings. Additionally, this strain also enhanced the endogenous level of two isoflavones including daidzen and genistein in soybean seedlings under normal as well as salt stress conditions as compared to their respective controls. P. spadiceum AGH786 boosted the NaCl stress tolerance and growth in soybean, by modulating seedlings endogenous phytohormones and isoflavones suggesting a valuable contribution of this potent fungal biofertilizer in sustainable agriculture in salt affected soils. PMID:28473818

Drought stress leads to systemic induced susceptibility to a nectrotrophic fungus associated with mountain pine beetle in Pinus banksiana seedlings.

PubMed

Klutsch, Jennifer G; Shamoun, Simon Francis; Erbilgin, Nadir

2017-01-01

Conifers have complex defense responses to initial attacks by insects and pathogens that can have cascading effects on success of subsequent colonizers. However, drought can affect a plant's ability to respond to biotic agents by potentially altering the resources needed for the energetically costly production of induced defense chemicals. We investigated the impact of reduced water on induced chemical defenses of jack pine (Pinus banksiana) seedlings from initial attack by biotic agents and resistance to subsequent challenge inoculation with a pathogenic fungal associate of mountain pine beetle (Dendroctonus ponderosae), Grosmannia clavigera. Applications of phytohormones (methyl salicylate and methyl jasmonate) and G. clavigera were used for initial induction of defenses. Monoterpene concentrations varied with initial induction from fungal and phytohormone application while watering treatment had no effect. Seedlings treated with G. clavigera and methyl jasmonate had the greatest monoterpene concentrations compared to the control and methyl salicylate-treated seedlings. However, the monoterpene response to the challenge inoculation varied with watering treatments, not with prior induction treatments, with lower monoterpene concentrations in fungal lesions on seedlings in the low to moderate watering treatments compared to normal watering treatment. Furthermore, prior induction from phytohormones resulted in systemic cross-induction of resistance to G. clavigera under normal watering treatment but susceptibility under low watering treatment. Seedlings stressed by low water conditions, which also had lower stomatal conductance than seedlings in the normal watering treatment, likely allocated resources to initial defense response but were left unable to acquire further resources for subsequent responses. Our results demonstrate that drought can affect interactions among tree-infesting organisms through systemic cross-induction of susceptibility.

Drought stress leads to systemic induced susceptibility to a nectrotrophic fungus associated with mountain pine beetle in Pinus banksiana seedlings

PubMed Central

Shamoun, Simon Francis; Erbilgin, Nadir

2017-01-01

Conifers have complex defense responses to initial attacks by insects and pathogens that can have cascading effects on success of subsequent colonizers. However, drought can affect a plant’s ability to respond to biotic agents by potentially altering the resources needed for the energetically costly production of induced defense chemicals. We investigated the impact of reduced water on induced chemical defenses of jack pine (Pinus banksiana) seedlings from initial attack by biotic agents and resistance to subsequent challenge inoculation with a pathogenic fungal associate of mountain pine beetle (Dendroctonus ponderosae), Grosmannia clavigera. Applications of phytohormones (methyl salicylate and methyl jasmonate) and G. clavigera were used for initial induction of defenses. Monoterpene concentrations varied with initial induction from fungal and phytohormone application while watering treatment had no effect. Seedlings treated with G. clavigera and methyl jasmonate had the greatest monoterpene concentrations compared to the control and methyl salicylate-treated seedlings. However, the monoterpene response to the challenge inoculation varied with watering treatments, not with prior induction treatments, with lower monoterpene concentrations in fungal lesions on seedlings in the low to moderate watering treatments compared to normal watering treatment. Furthermore, prior induction from phytohormones resulted in systemic cross-induction of resistance to G. clavigera under normal watering treatment but susceptibility under low watering treatment. Seedlings stressed by low water conditions, which also had lower stomatal conductance than seedlings in the normal watering treatment, likely allocated resources to initial defense response but were left unable to acquire further resources for subsequent responses. Our results demonstrate that drought can affect interactions among tree-infesting organisms through systemic cross-induction of susceptibility. PMID:29216258

Physiological response to drought in radiata pine: phytohormone implication at leaf level.

PubMed

De Diego, N; Pérez-Alfocea, F; Cantero, E; Lacuesta, M; Moncaleán, P

2012-04-01

Pinus radiata D. Don is one of the most abundant species in the north of Spain. Knowledge of drought response mechanisms is essential to guarantee plantation survival under reduced water supply as predicted in the future. Tolerance mechanisms are being studied in breeding programs, because information on such mechanisms can be used for genotype selection. In this paper, we analyze the changes of leaf water potential, hydraulic conductance (K(leaf)), stomatal conductance and phytohormones under drought in P. radiata breeds (O1, O2, O3, O4, O5 and O6) from different climatology areas, hypothesizing that they could show variable drought tolerance. As a primary signal, drought decreased cytokinin (zeatin and zeatin riboside-Z + ZR) levels in needles parallel to K(leaf) and gas exchange. When Z + ZR decreased by 65%, indole-3-acetic acid (IAA) and abscisic acid (ABA) accumulation started as a second signal and increments were higher for IAA than for ABA. When plants decreased by 80%, Z + ZR and K(leaf) doubled their ABA and IAA levels, the photosystem II yield decreased and the electrolyte leakage increased. At the end of the drought period, less tolerant breeds increased IAA over 10-fold compared with controls. External damage also induced jasmonic acid accumulation in all breeds except in O5 (P. radiata var. radiata × var. cedrosensis), which accumulated salicylic acid as a defense mechanism. After rewatering, only the most tolerant plants recovered their K(leaf,) perhaps due to an IAA decrease and 1-aminocyclopropane-1-carboxylic acid maintenance. From all phytohormones, IAA was the most representative 'water deficit signal' in P. radiata.

The gall wasp Leptocybe invasa (Hymenoptera: Eulophidae) stimulates different chemical and phytohormone responses in two Eucalyptus varieties that vary in susceptibility to galling.

PubMed

Li, X Q; Liu, Y Z; Guo, W F; Solanki, M K; Yang, Z D; Xiang, Y; Ma, Z C; Wen, Y G

2017-09-01

Gall-inducing insects produce various types of galls on plants, but little is known about the gall-induction mechanism of these galling insects. The gall wasp Leptocybe invasa Fisher & LaSalle (Hymenoptera: Eulophidae) forms galls of different sizes on several Eucalyptus species. To clarify the physiological responses of Eucalyptus to L. invasa infestation, we measured the dynamics of nitrogen (N), carbon (C), total phenolics, total tannins and four types of phytohormones (zeatin [Z] + zeatin riboside [ZR], gibberellins [GA], indole-3-acetic acid [IAA] and abscisic acid [ABA]) in galled and ungalled leaf tissues of two Eucalyptus horticultural varieties (DH201-2 [Eucalyptus grandis × Eucalyptus camaldulensis] and EA [Eucalyptus exserta]) with different susceptibility to galling throughout the larval developmental stages. Nitrogen, total phenolics, tannins and four kinds of phytohormones strongly accumulated in tissues galled by L. invasa (especially during early larval feeding stages). While N, Z + ZR and GA levels were higher, tannins and ABA levels were lower in the galled tissues on the highly susceptible variety. Nitrogen, total phenolics, GA, Z + ZR and IAA levels in the galled tissues gradually decreased during gall development, but ABA and tannins conversely increased in the galled tissues of the less susceptible variety. Our results suggest that the effects of gall-inducing insects on plants depend not only on the susceptibility of the plant infested but also on the developmental stage of galled tissues. Gall formation process is thus synergistically influenced by both gall-inducing insect and plant genotypes. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Revisiting the Therapeutic Potential of Bothrops jararaca Venom: Screening for Novel Activities Using Connectivity Mapping

PubMed Central

Nicolau, Carolina Alves; Prorock, Alyson; Bao, Yongde; Neves-Ferreira, Ana Gisele da Costa; Fox, Jay William

2018-01-01

Snake venoms are sources of molecules with proven and potential therapeutic applications. However, most activities assayed in venoms (or their components) are of hemorrhagic, hypotensive, edematogenic, neurotoxic or myotoxic natures. Thus, other relevant activities might remain unknown. Using functional genomics coupled to the connectivity map (C-map) approach, we undertook a wide range indirect search for biological activities within the venom of the South American pit viper Bothrops jararaca. For that effect, venom was incubated with human breast adenocarcinoma cell line (MCF7) followed by RNA extraction and gene expression analysis. A list of 90 differentially expressed genes was submitted to biosimilar drug discovery based on pattern recognition. Among the 100 highest-ranked positively correlated drugs, only the antihypertensive, antimicrobial (both antibiotic and antiparasitic), and antitumor classes had been previously reported for B. jararaca venom. The majority of drug classes identified were related to (1) antimicrobial activity; (2) treatment of neuropsychiatric illnesses (Parkinson’s disease, schizophrenia, depression, and epilepsy); (3) treatment of cardiovascular diseases, and (4) anti-inflammatory action. The C-map results also indicated that B. jararaca venom may have components that target G-protein-coupled receptors (muscarinic, serotonergic, histaminergic, dopaminergic, GABA, and adrenergic) and ion channels. Although validation experiments are still necessary, the C-map correlation to drugs with activities previously linked to snake venoms supports the efficacy of this strategy as a broad-spectrum approach for biological activity screening, and rekindles the snake venom-based search for new therapeutic agents. PMID:29415440

Systematic analysis of transcription start sites in avian development.

PubMed

Lizio, Marina; Deviatiiarov, Ruslan; Nagai, Hiroki; Galan, Laura; Arner, Erik; Itoh, Masayoshi; Lassmann, Timo; Kasukawa, Takeya; Hasegawa, Akira; Ros, Marian A; Hayashizaki, Yoshihide; Carninci, Piero; Forrest, Alistair R R; Kawaji, Hideya; Gusev, Oleg; Sheng, Guojun

2017-09-01

Cap Analysis of Gene Expression (CAGE) in combination with single-molecule sequencing technology allows precision mapping of transcription start sites (TSSs) and genome-wide capture of promoter activities in differentiated and steady state cell populations. Much less is known about whether TSS profiling can characterize diverse and non-steady state cell populations, such as the approximately 400 transitory and heterogeneous cell types that arise during ontogeny of vertebrate animals. To gain such insight, we used the chick model and performed CAGE-based TSS analysis on embryonic samples covering the full 3-week developmental period. In total, 31,863 robust TSS peaks (>1 tag per million [TPM]) were mapped to the latest chicken genome assembly, of which 34% to 46% were active in any given developmental stage. ZENBU, a web-based, open-source platform, was used for interactive data exploration. TSSs of genes critical for lineage differentiation could be precisely mapped and their activities tracked throughout development, suggesting that non-steady state and heterogeneous cell populations are amenable to CAGE-based transcriptional analysis. Our study also uncovered a large set of extremely stable housekeeping TSSs and many novel stage-specific ones. We furthermore demonstrated that TSS mapping could expedite motif-based promoter analysis for regulatory modules associated with stage-specific and housekeeping genes. Finally, using Brachyury as an example, we provide evidence that precise TSS mapping in combination with Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR)-on technology enables us, for the first time, to efficiently target endogenous avian genes for transcriptional activation. Taken together, our results represent the first report of genome-wide TSS mapping in birds and the first systematic developmental TSS analysis in any amniote species (birds and mammals). By facilitating promoter-based molecular analysis and genetic manipulation, our work also underscores the value of avian models in unravelling the complex regulatory mechanism of cell lineage specification during amniote development.

Areas activated during naturalistic reading comprehension overlap topological visual, auditory, and somatotomotor maps

PubMed Central

2016-01-01

Abstract Cortical mapping techniques using fMRI have been instrumental in identifying the boundaries of topological (neighbor‐preserving) maps in early sensory areas. The presence of topological maps beyond early sensory areas raises the possibility that they might play a significant role in other cognitive systems, and that topological mapping might help to delineate areas involved in higher cognitive processes. In this study, we combine surface‐based visual, auditory, and somatomotor mapping methods with a naturalistic reading comprehension task in the same group of subjects to provide a qualitative and quantitative assessment of the cortical overlap between sensory‐motor maps in all major sensory modalities, and reading processing regions. Our results suggest that cortical activation during naturalistic reading comprehension overlaps more extensively with topological sensory‐motor maps than has been heretofore appreciated. Reading activation in regions adjacent to occipital lobe and inferior parietal lobe almost completely overlaps visual maps, whereas a significant portion of frontal activation for reading in dorsolateral and ventral prefrontal cortex overlaps both visual and auditory maps. Even classical language regions in superior temporal cortex are partially overlapped by topological visual and auditory maps. By contrast, the main overlap with somatomotor maps is restricted to a small region on the anterior bank of the central sulcus near the border between the face and hand representations of M‐I. Hum Brain Mapp 37:2784–2810, 2016. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc. PMID:27061771

Herbivory by Thrips tabaci

Treesearch

Deborah M. Kendall

1991-01-01

Herbivory by Thrips tabaci (Lindeman) affects both the bulb yield and phytohormone balance in its major host plant, the onion (Alium cepa L.). Seasonal changes in the susceptibility of onion yield to T. tabaci feeding were examined during the three growth stages of onion; prebulbing, bulbing and sizing (Kendall...

Gibberllin driven growth in elf3 mutants requires PIF4 and PIF5

USDA-ARS?s Scientific Manuscript database

The regulatory connections between the circadian clock and hormone signaling are essential to understand, as these two regulatory processes work together to time growth processes relative to predictable environmental events. Gibberellins (GAs) are phytohormones that control many growth processes thr...

Physical Webbing: Collaborative Kinesthetic Three-Dimensional Mind Maps[R

ERIC Educational Resources Information Center

Williams, Marian H.

2012-01-01

Mind Mapping has predominantly been used by individuals or collaboratively in groups as a paper-based or computer-generated learning strategy. In an effort to make Mind Mapping kinesthetic, collaborative, and three-dimensional, an innovative pedagogical strategy, termed Physical Webbing, was devised. In the Physical Web activity, groups…

Influence of low-intensity laser radiation on the dynamics of some phytohormone content in the callus tissues of wheat Triticum aestivum L.

NASA Astrophysics Data System (ADS)

Dudareva, L. V.; Rudikovskaya, E. G.; Shmakov, V. N.; Rudikovskii, A. V.; Salyaev, R. K.

2017-05-01

We carried out an analysis of the influence of low-intensity He-Ne laser radiation on the dynamics of changes observed in the content of the phytohormones abscisic, jasmonic, salicylic, and indoleacetic acids in wheat calluses of Triticum aestivum L. using chromatography-mass spectrometry. He-Ne laser irradiation (λ  =  632.8 nm) in its stimulant dose (3.5 J cm-2) was proved to cause a decrease in jasmonic and indoleacetic acid content and, simultaneously, a significant (2.5-3 times) increase in ‘stress’ abscisic and salicylic acids. The response of jasmonic acid to He-Cd laser irradiation (λ  =  441 nm) was specific, which is probably due to the blue-light-induced biosynthesis of the acid. This article discusses a possible connection between substantial changes in growth regulator content within the plant tissue under the influence of low-intensity laser irradiation and the stress character of this type of radiation.

Pseudomonas syringae Type III Effector HopBB1 Promotes Host Transcriptional Repressor Degradation to Regulate Phytohormone Responses and Virulence.

PubMed

Yang, Li; Teixeira, Paulo José Pereira Lima; Biswas, Surojit; Finkel, Omri M; He, Yijian; Salas-Gonzalez, Isai; English, Marie E; Epple, Petra; Mieczkowski, Piotr; Dangl, Jeffery L

2017-02-08

Independently evolved pathogen effectors from three branches of life (ascomycete, eubacteria, and oomycete) converge onto the Arabidopsis TCP14 transcription factor to manipulate host defense. However, the mechanistic basis for defense control via TCP14 regulation is unknown. We demonstrate that TCP14 regulates the plant immune system by transcriptionally repressing a subset of the jasmonic acid (JA) hormone signaling outputs. A previously unstudied Pseudomonas syringae (Psy) type III effector, HopBB1, interacts with TCP14 and targets it to the SCF COI1 degradation complex by connecting it to the JA signaling repressor JAZ3. Consequently, HopBB1 de-represses the TCP14-regulated subset of JA response genes and promotes pathogen virulence. Thus, HopBB1 fine-tunes host phytohormone crosstalk by precisely manipulating part of the JA regulon to avoid pleiotropic host responses while promoting pathogen proliferation. Copyright © 2017 Elsevier Inc. All rights reserved.

Ethylene Role in Plant Growth, Development and Senescence: Interaction with Other Phytohormones

PubMed Central

Iqbal, Noushina; Khan, Nafees A.; Ferrante, Antonio; Trivellini, Alice; Francini, Alessandra; Khan, M. I. R.

2017-01-01

The complex juvenile/maturity transition during a plant’s life cycle includes growth, reproduction, and senescence of its fundamental organs: leaves, flowers, and fruits. Growth and senescence of leaves, flowers, and fruits involve several genetic networks where the phytohormone ethylene plays a key role, together with other hormones, integrating different signals and allowing the onset of conditions favorable for stage progression, reproductive success and organ longevity. Changes in ethylene level, its perception, and the hormonal crosstalk directly or indirectly regulate the lifespan of plants. The present review focused on ethylene’s role in the development and senescence processes in leaves, flowers and fruits, paying special attention to the complex networks of ethylene crosstalk with other hormones. Moreover, aspects with limited information have been highlighted for future research, extending our understanding on the importance of ethylene during growth and senescence and boosting future research with the aim to improve the qualitative and quantitative traits of crops. PMID:28421102

Jasmonic Acid, Abscisic Acid, and Salicylic Acid Are Involved in the Phytoalexin Responses of Rice to Fusarium fujikuroi, a High Gibberellin Producer Pathogen.

PubMed

Siciliano, Ilenia; Amaral Carneiro, Greice; Spadaro, Davide; Garibaldi, Angelo; Gullino, Maria Lodovica

2015-09-23

Fusarium fujikuroi, the causal agent of bakanae disease, is the main seedborne pathogen on rice. To understand the basis of rice resistance, a quantitative method to simultaneously detect phytohormones and phytoalexins was developed by using HPLC-MS/MS. With this method dynamic profiles and possible interactions of defense-related phytohormones and phytoalexins were investigated on two rice cultivars, inoculated or not with F. fujikuroi. In the resistant cultivar Selenio, the presence of pathogen induced high production of phytoalexins, mainly sakuranetin, and symptoms of bakanae were not observed. On the contrary, in the susceptible genotype Dorella, the pathogen induced the production of gibberellin and abscisic acid and inhibited jasmonic acid production, phytoalexins were very low, and bakanae symptoms were observed. The results suggested that a wide range of secondary metabolites are involved in plant defense against pathogens and phytoalexin synthesis could be an important factor for rice resistance against bakanae disease.

The mapping of eccentricity and meridional angle onto orthogonal axes in the primary visual cortex: an activity-dependent developmental model.

PubMed

Philips, Ryan T; Chakravarthy, V Srinivasa

2015-01-01

Primate vision research has shown that in the retinotopic map of the primary visual cortex, eccentricity and meridional angle are mapped onto two orthogonal axes: whereas the eccentricity is mapped onto the nasotemporal axis, the meridional angle is mapped onto the dorsoventral axis. Theoretically such a map has been approximated by a complex log map. Neural models with correlational learning have explained the development of other visual maps like orientation maps and ocular-dominance maps. In this paper it is demonstrated that activity based mechanisms can drive a self-organizing map (SOM) into such a configuration that dilations and rotations of a particular image (in this case a rectangular bar) are mapped onto orthogonal axes. We further demonstrate using the Laterally Interconnected Synergetically Self Organizing Map (LISSOM) model, with an appropriate boundary and realistic initial conditions, that a retinotopic map which maps eccentricity and meridional angle to the horizontal and vertical axes respectively can be developed. This developed map bears a strong resemblance to the complex log map. We also simulated lesion studies which indicate that the lateral excitatory connections play a crucial role in development of the retinotopic map.

A teaching-learning sequence about weather map reading

NASA Astrophysics Data System (ADS)

Mandrikas, Achilleas; Stavrou, Dimitrios; Skordoulis, Constantine

2017-07-01

In this paper a teaching-learning sequence (TLS) introducing pre-service elementary teachers (PET) to weather map reading, with emphasis on wind assignment, is presented. The TLS includes activities about recognition of wind symbols, assignment of wind direction and wind speed on a weather map and identification of wind characteristics in a weather forecast. Sixty PET capabilities and difficulties in understanding weather maps were investigated, using inquiry-based learning activities. The results show that most PET became more capable of reading weather maps and assigning wind direction and speed on them. Our results also show that PET could be guided to understand meteorology concepts useful in everyday life and in teaching their future students.

Areas activated during naturalistic reading comprehension overlap topological visual, auditory, and somatotomotor maps.

PubMed

Sood, Mariam R; Sereno, Martin I

2016-08-01

Cortical mapping techniques using fMRI have been instrumental in identifying the boundaries of topological (neighbor-preserving) maps in early sensory areas. The presence of topological maps beyond early sensory areas raises the possibility that they might play a significant role in other cognitive systems, and that topological mapping might help to delineate areas involved in higher cognitive processes. In this study, we combine surface-based visual, auditory, and somatomotor mapping methods with a naturalistic reading comprehension task in the same group of subjects to provide a qualitative and quantitative assessment of the cortical overlap between sensory-motor maps in all major sensory modalities, and reading processing regions. Our results suggest that cortical activation during naturalistic reading comprehension overlaps more extensively with topological sensory-motor maps than has been heretofore appreciated. Reading activation in regions adjacent to occipital lobe and inferior parietal lobe almost completely overlaps visual maps, whereas a significant portion of frontal activation for reading in dorsolateral and ventral prefrontal cortex overlaps both visual and auditory maps. Even classical language regions in superior temporal cortex are partially overlapped by topological visual and auditory maps. By contrast, the main overlap with somatomotor maps is restricted to a small region on the anterior bank of the central sulcus near the border between the face and hand representations of M-I. Hum Brain Mapp 37:2784-2810, 2016. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

A qualitative study on using concept maps in problem-based learning.

PubMed

Chan, Zenobia C Y

2017-05-01

The visual arts, including concept maps, have been shown to be effective tools for facilitating student learning. However, the use of concept maps in nursing education has been under-explored. The aim of this study was to explore how students develop concept maps and what these concept maps consist of, and their views on the use of concept maps as a learning activity in a PBL class. A qualitative approach consisting of an analysis of the contents of the concept maps and interviews with students. The study was conducted in a school of nursing in a university in Hong Kong. A total of 38 students who attended the morning session (20 students) and afternoon session (18 students) respectively of a nursing problem-based learning class. The students in both the morning and afternoon classes were allocated into four groups (4-5 students per group). Each group was asked to draw two concept maps based on a given scenario, and then to participate in a follow-up interview. Two raters individually assessed the concept maps, and then discussed their views with each other. Among the concept maps that were drawn, four were selected. Their four core features of those maps were: a) the integration of informative and artistic elements; b) the delivery of sensational messages; c) the use of images rather than words; and d) three-dimensional and movable. Both raters were concerned about how informative the presentation was, the composition of the elements, and the ease of comprehension, and appreciated the three-dimensional presentation and effective use of images. From the results of the interview, the pros and cons of using concept maps were discerned. This study demonstrated how concept maps could be implemented in a PBL class to boost the students' creativity and to motivate them to learn. This study suggests the use of concept maps as an initiative to motivate student to learn, participate actively, and nurture their creativity. To conclude, this study explored an alternative way for students to make presentations and pioneered the use of art-based concept maps to facilitate student learning. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of plant growth regulators to increase Ni phytoextraction by Alyssum species

USDA-ARS?s Scientific Manuscript database

Recent studies have shown that application of phytohormones to shoots of Alyssum murale increased biomass production but did not increase Ni shoot concentration. Increased biomass and Ni phytoextraction efficiency is useful to achieve economically viable phytomining. The objective of this study wa...

Biological Networks Underlying Soybean Seed Oil Composition and Content

USDA-ARS?s Scientific Manuscript database

Soybean is the most important oil crop in the United States. Production of soybean seed oil requires coordinated expression of many biological components and pathways, which is further regulated by seed development and phyto-hormones. A new research project is initiated in my laboratory to delineat...

Identification of Differentially Expressed Genes in Chilling-Induced Potato (Solanum tuberosum L.); a Data Analysis Study.

PubMed

Koc, I; Vatansever, R; Ozyigit, I I; Filiz, E

2015-10-01

Cold stress, as chilling (<20 °C) or freezing (<0 °C), is one of the frequently exposed stresses in cultivated plants like potato. Under cold stress, plants differentially modulate their gene expression to develop a cold tolerance/acclimation. In the present study, we aimed to identify the overall gene expression profile of chilling-stressed (+4 °C) potato at four time points (4, 8, 12, and 48 h), with a particular emphasis on the genes related with transcription factors (TFs), phytohormones, lipid metabolism, signaling pathway, and photosynthesis. A total of 3504 differentially expressed genes (DEGs) were identified at four time points of chilling-induced potato, of which 1397 were found to be up-regulated while 2107 were down-regulated. Heatmap showed that genes were mainly up-regulated at 4-, 8-, and 12-h time points; however, at 48-h time point, they inclined to down-regulate. Seventy five up-regulated TF genes were identified from 37 different families/groups, including mainly from bHLH, WRKY, CCAAT-binding, HAP3, and bZIP families. Protein kinases and calcium were major signaling molecules in cold-induced signaling pathway. A collaborated regulation of phytohormones was observed in chilling-stressed potato. Lipid metabolisms were regulated in a way, highly probably, to change membrane composition to avoid cold damage and render in signaling. A down-regulated gene expression profile was observed in photosynthesis pathway, probably resulting from chilling-induced reduced enzyme activity or light-triggered ROSs damage. The findings of this study will be a valuable theoretical knowledge in terms of understanding the chilling-induced tolerance mechanisms in cultivated potato plants as well as in other Solanum species.

Early events in Agrobacterium-mediated genetic transformation of citrus explants.

PubMed

Peña, Leandro; Pérez, Rosa M; Cervera, Magdalena; Juárez, José A; Navarro, Luis

2004-07-01

Genetic transformation of plants relies on two independent but concurrent processes: integration of foreign DNA into plant cells and regeneration of whole plants from these transformed cells. Cell competence for regeneration and for transformation does not always fall into the same cell type/developmental stage, and this is one of the main causes of the so-called recalcitrance for transformation of certain plant species. In this study, a detailed examination of the first steps of morphogenesis from citrus explants after co-cultivation with Agrobacterium tumefaciens was performed, and an investigation into which cells and tissues are competent for regeneration and transformation was carried out. Moreover, the role of phytohormones in the co-cultivation medium as possible enhancers of gene transfer was also studied. A highly responsive citrus genotype and well-established culture conditions were used to perform a histological analysis of morphogenesis and cell competence for transformation after co-cultivation of citrus epicotyl segments with A. tumefaciens. In addition, the role of phytohormones as transformation enhancers was investigated by flow cytometry. It is demonstrated that cells competent for transformation are located in the newly formed callus growing from the cambial ring. Conditions conducive to further development of this callus, such as treatment of explants in a medium rich in auxins, resulted in a more pronounced formation of cambial callus and a slower shoot regeneration process, both in Agrobacterium-inoculated and non-inoculated explants. Furthermore, co- cultivation in a medium rich in auxins caused a significant increase in the rate of actively dividing cells in S-phase, the stage in which cells are more prone to integrate foreign DNA. Use of proper co-cultivation medium and conditions led to a higher number of stably transformed cells and to an increase in the final number of regenerated transgenic plants.

Striking the Right Chord: Signaling Enigma during Root Gravitropism

PubMed Central

Singh, Manjul; Gupta, Aditi; Laxmi, Ashverya

2017-01-01

Plants being sessile can often be judged as passive acceptors of their environment. However, plants are actually even more active in responding to the factors from their surroundings. Plants do not have eyes, ears or vestibular system like animals, still they “know” which way is up and which way is down? This is facilitated by receptor molecules within plant which perceive changes in internal and external conditions such as light, touch, obstacles; and initiate signaling pathways that enable the plant to react. Plant responses that involve a definite and specific movement are called “tropic” responses. Perhaps the best known and studied tropisms are phototropism, i.e., response to light, and geotropism, i.e., response to gravity. A robust root system is vital for plant growth as it can provide physical anchorage to soil as well as absorb water, nutrients and essential minerals from soil efficiently. Gravitropic responses of both primary as well as lateral root thus become critical for plant growth and development. The molecular mechanisms of root gravitropism has been delved intensively, however, the mechanism behind how the potential energy of gravity stimulus converts into a biochemical signal in vascular plants is still unknown, due to which gravity sensing in plants still remains one of the most fascinating questions in molecular biology. Communications within plants occur through phytohormones and other chemical substances produced in plants which have a developmental or physiological effect on growth. Here, we review current knowledge of various intrinsic signaling mechanisms that modulate root gravitropism in order to point out the questions and emerging developments in plant directional growth responses. We are also discussing the roles of sugar signals and their interaction with phytohormone machinery, specifically in context of root directional responses. PMID:28798760

Striking the Right Chord: Signaling Enigma during Root Gravitropism.

PubMed

Singh, Manjul; Gupta, Aditi; Laxmi, Ashverya

2017-01-01

Plants being sessile can often be judged as passive acceptors of their environment. However, plants are actually even more active in responding to the factors from their surroundings. Plants do not have eyes, ears or vestibular system like animals, still they "know" which way is up and which way is down? This is facilitated by receptor molecules within plant which perceive changes in internal and external conditions such as light, touch, obstacles; and initiate signaling pathways that enable the plant to react. Plant responses that involve a definite and specific movement are called "tropic" responses. Perhaps the best known and studied tropisms are phototropism, i.e., response to light, and geotropism, i.e., response to gravity. A robust root system is vital for plant growth as it can provide physical anchorage to soil as well as absorb water, nutrients and essential minerals from soil efficiently. Gravitropic responses of both primary as well as lateral root thus become critical for plant growth and development. The molecular mechanisms of root gravitropism has been delved intensively, however, the mechanism behind how the potential energy of gravity stimulus converts into a biochemical signal in vascular plants is still unknown, due to which gravity sensing in plants still remains one of the most fascinating questions in molecular biology. Communications within plants occur through phytohormones and other chemical substances produced in plants which have a developmental or physiological effect on growth. Here, we review current knowledge of various intrinsic signaling mechanisms that modulate root gravitropism in order to point out the questions and emerging developments in plant directional growth responses. We are also discussing the roles of sugar signals and their interaction with phytohormone machinery, specifically in context of root directional responses.

Influence of plant maturity, shoot reproduction and sex on vegetative growth in the dioecious plant Urtica dioica.

PubMed

Oñate, Marta; Munné-Bosch, Sergi

2009-10-01

Stinging nettle (Urtica dioica) is a herbaceous, dioecious perennial that is widely distributed around the world, reproduces both sexually and asexually, and is characterized by rapid growth. This work was aimed at evaluating the effects of plant maturity, shoot reproduction and sex on the growth of leaves and shoots. Growth rates of apical shoots, together with foliar levels of phytohormones (cytokinins, auxins, absicisic acid, jasmonic acid and salicylic acid) and other indicators of leaf physiology (water contents, photosynthetic pigments, alpha-tocopherol and F(v)/F(m) ratios) were measured in juvenile and mature plants, with a distinction made between reproductive and non-reproductive shoots in both males and females. Vegetative growth rates were not only evaluated in field-grown plants, but also in cuttings obtained from these plants. All measurements were performed during an active vegetative growth phase in autumn, a few months after mature plants reproduced during spring and summer. Vegetative growth rates in mature plants were drastically reduced compared with juvenile ones (48 % and 78 % for number of leaves and leaf biomass produced per day, respectively), which was associated with a loss of photosynthetic pigments (up to 24 % and 48 % for chlorophylls and carotenoids, respectively) and increases of alpha-tocopherol (up to 2.7-fold), while endogenous levels of phytohormones did not differ between mature and juvenile plants. Reductions in vegetative growth were particularly evident in reproductive shoots of mature plants, and occurred similarly in both males and females. It is concluded that (a) plant maturity reduces vegetative growth in U. dioica, (b) effects of plant maturity are evident both in reproductive and non-reproductive shoots, but particularly in the former, and (c) these changes occur similarly in both male and female plants.

Influence of plant maturity, shoot reproduction and sex on vegetative growth in the dioecious plant Urtica dioica

PubMed Central

Oñate, Marta; Munné-Bosch, Sergi

2009-01-01

Background and Aims Stinging nettle (Urtica dioica) is a herbaceous, dioecious perennial that is widely distributed around the world, reproduces both sexually and asexually, and is characterized by rapid growth. This work was aimed at evaluating the effects of plant maturity, shoot reproduction and sex on the growth of leaves and shoots. Methods Growth rates of apical shoots, together with foliar levels of phytohormones (cytokinins, auxins, absicisic acid, jasmonic acid and salicylic acid) and other indicators of leaf physiology (water contents, photosynthetic pigments, α-tocopherol and Fv/Fm ratios) were measured in juvenile and mature plants, with a distinction made between reproductive and non-reproductive shoots in both males and females. Vegetative growth rates were not only evaluated in field-grown plants, but also in cuttings obtained from these plants. All measurements were performed during an active vegetative growth phase in autumn, a few months after mature plants reproduced during spring and summer. Key Results Vegetative growth rates in mature plants were drastically reduced compared with juvenile ones (48 % and 78 % for number of leaves and leaf biomass produced per day, respectively), which was associated with a loss of photosynthetic pigments (up to 24 % and 48 % for chlorophylls and carotenoids, respectively) and increases of α-tocopherol (up to 2·7-fold), while endogenous levels of phytohormones did not differ between mature and juvenile plants. Reductions in vegetative growth were particularly evident in reproductive shoots of mature plants, and occurred similarly in both males and females. Conclusions It is concluded that (a) plant maturity reduces vegetative growth in U. dioica, (b) effects of plant maturity are evident both in reproductive and non-reproductive shoots, but particularly in the former, and (c) these changes occur similarly in both male and female plants. PMID:19633309

Volcanic Hazards Survey in the Trans Mexican Volcanic Belt

NASA Technical Reports Server (NTRS)

Abrams, Michael; Siebe, Claus; Macias, Jose Luis

1996-01-01

We have assembled a digital mosaic of 11 Landsat Thematic images to serve as a mapping base for reconnaissance activities within the Trans Mexican Volcanic Belt. This will aid us in interpretation and in the evaluation of potential activity of all the volcanic centers there. One result is a volcanic hazards map of the area.

Metabolomics analysis reveals 6‐benzylaminopurine as a stimulator for improving lipid and DHA accumulation of Aurantiochytriumsp.

PubMed Central

Yu, Xin‐Jun; Sun, Jie; Zheng, Jian‐Yong; Sun, Ya‐Qi

2016-01-01

Abstract BACKGROUND Phytohormones are chemical messengers that have a positive effect on biodiesel production of microalgae at low concentrations. However, the effect of phytohormone 6‐benzylaminopurine on lipid and docosahexaenoic acid (DHA) production in marine DHA‐producer Aurantiochytrium has never been reported. In this study, a GC‐MS‐based metabolomics method combined with a multivariate analysis is applied to reveal the metabolic mechanism of 6‐benzylaminopurine enhancing production of lipid and DHA in Aurantiochytrium sp.YLH70. RESULTS In total, 71 metabolites were identified by GC‐MS. The PCA model revealed that 76.9% of metabolite variation was related to 6‐benzylaminopurine treatment, and overall metabolomics profiles between the 6‐benzylaminopurine and control groups were clearly discriminated. Forty‐six metabolites identified by the PLS‐DA model were responsible for responding to 6‐benzylaminopurine. Metabolic analysis showed that 6‐benzylaminopurine could accelerate the rate of utilization of glucose in Aurantiochytrium sp. YLH70, and the metabolic flux from glycolysis, TCA cycle and mevalonate pathway to fatty acids biosynthesis was promoted. Moreover, the anti‐stress mechanism in Aurantiochytrium sp.YLH70 might be induced by 6‐benzylaminopurine. CONCLUSION Metabolomics is a suitable tool to discover the metabolic mechanism for improving lipid and DHA accumulation in a microorganism. 6‐benzylaminopurine has the potential to stimulate lipid and DHA production of Aurantiochytrium sp.YLH70 for industrial purposes. © 2015 The Authors. Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. PMID:27065509

Electromechanical Wave Imaging (EWI) validation in all four cardiac chambers with 3D electroanatomic mapping in canines in vivo

PubMed Central

Costet, Alexandre; Wan, Elaine; Bunting, Ethan; Grondin, Julien; Garan, Hasan; Konofagou, Elisa

2016-01-01

Characterization and mapping of arrhythmias is currently performed through invasive insertion and manipulation of cardiac catheters. Electromechanical wave imaging (EWI) is a non-invasive ultrasound-based imaging technique, which tracks the electromechanical activation that immediately follows electrical activation. Electrical and electromechanical activations were previously found to be linearly correlated in the left ventricle, but the relationship has not yet been investigated in the three other chambers of the heart. The objective of this study was to investigate the relationship between electrical and electromechanical activations and validate EWI in all four chambers of the heart with conventional 3D electroanatomical mapping. Six (n = 6) normal adult canines were used in this study. The electrical activation sequence was mapped in all four chambers of the heart, both endocardially and epicardially using the St Jude's EnSite 3D mapping system (St. Jude Medical, Secaucus, NJ). EWI acquisitions were performed in all four chambers during normal sinus rhythm, and during pacing in the left ventricle. Isochrones of the electromechanical activation were generated from standard echocardiographic imaging views. Electrical and electromechanical activation maps were co-registered and compared, and electrical and electromechanical activation times were plotted against each other and linear regression was performed for each pair of activation maps. Electromechanical and electrical activations were found to be directly correlated with slopes of the correlation ranging from 0.77 to 1.83, electromechanical delays between 9 and 58 ms and R2 values from 0.71 to 0.92. The linear correlation between electrical and electromechanical activations and the agreement between the activation maps indicate that the electromechanical activation follows the pattern of propagation of the electrical activation. This suggests that EWI may be used as a novel non-invasive method to accurately characterize and localize sources of arrhythmias. PMID:27782003

Electromechanical wave imaging (EWI) validation in all four cardiac chambers with 3D electroanatomic mapping in canines in vivo.

PubMed

Costet, Alexandre; Wan, Elaine; Bunting, Ethan; Grondin, Julien; Garan, Hasan; Konofagou, Elisa

2016-11-21

Characterization and mapping of arrhythmias is currently performed through invasive insertion and manipulation of cardiac catheters. Electromechanical wave imaging (EWI) is a non-invasive ultrasound-based imaging technique, which tracks the electromechanical activation that immediately follows electrical activation. Electrical and electromechanical activations were previously found to be linearly correlated in the left ventricle, but the relationship has not yet been investigated in the three other chambers of the heart. The objective of this study was to investigate the relationship between electrical and electromechanical activations and validate EWI in all four chambers of the heart with conventional 3D electroanatomical mapping. Six (n  =  6) normal adult canines were used in this study. The electrical activation sequence was mapped in all four chambers of the heart, both endocardially and epicardially using the St Jude's EnSite 3D mapping system (St. Jude Medical, Secaucus, NJ). EWI acquisitions were performed in all four chambers during normal sinus rhythm, and during pacing in the left ventricle. Isochrones of the electromechanical activation were generated from standard echocardiographic imaging views. Electrical and electromechanical activation maps were co-registered and compared, and electrical and electromechanical activation times were plotted against each other and linear regression was performed for each pair of activation maps. Electromechanical and electrical activations were found to be directly correlated with slopes of the correlation ranging from 0.77 to 1.83, electromechanical delays between 9 and 58 ms and R 2 values from 0.71 to 0.92. The linear correlation between electrical and electromechanical activations and the agreement between the activation maps indicate that the electromechanical activation follows the pattern of propagation of the electrical activation. This suggests that EWI may be used as a novel non-invasive method to accurately characterize and localize sources of arrhythmias.

Dual RNA-seq transcriptional analysis of wheat roots colonized by Azospirillum brasilense reveals up-regulation of nutrient acquisition and cell cycle genes.

PubMed

Camilios-Neto, Doumit; Bonato, Paloma; Wassem, Roseli; Tadra-Sfeir, Michelle Z; Brusamarello-Santos, Liziane C C; Valdameri, Glaucio; Donatti, Lucélia; Faoro, Helisson; Weiss, Vinicius A; Chubatsu, Leda S; Pedrosa, Fábio O; Souza, Emanuel M

2014-05-16

The rapid growth of the world's population demands an increase in food production that no longer can be reached by increasing amounts of nitrogenous fertilizers. Plant growth promoting bacteria (PGPB) might be an alternative to increase nitrogenous use efficiency (NUE) in important crops such wheat. Azospirillum brasilense is one of the most promising PGPB and wheat roots colonized by A. brasilense is a good model to investigate the molecular basis of plant-PGPB interaction including improvement in plant-NUE promoted by PGPB. We performed a dual RNA-Seq transcriptional profiling of wheat roots colonized by A. brasilense strain FP2. cDNA libraries from biological replicates of colonized and non-inoculated wheat roots were sequenced and mapped to wheat and A. brasilense reference sequences. The unmapped reads were assembled de novo. Overall, we identified 23,215 wheat expressed ESTs and 702 A. brasilense expressed transcripts. Bacterial colonization caused changes in the expression of 776 wheat ESTs belonging to various functional categories, ranging from transport activity to biological regulation as well as defense mechanism, production of phytohormones and phytochemicals. In addition, genes encoding proteins related to bacterial chemotaxi, biofilm formation and nitrogen fixation were highly expressed in the sub-set of A. brasilense expressed genes. PGPB colonization enhanced the expression of plant genes related to nutrient up-take, nitrogen assimilation, DNA replication and regulation of cell division, which is consistent with a higher proportion of colonized root cells in the S-phase. Our data support the use of PGPB as an alternative to improve nutrient acquisition in important crops such as wheat, enhancing plant productivity and sustainability.

E-Activities: Internet-based Activities To Expand Your History Curriculum.

ERIC Educational Resources Information Center

Trumbauer, Lisa

2002-01-01

Presents three Internet-based activities for teaching elementary students about the Underground Railroad. The activities include creating a freight-train of facts about the Underground Railroad, mapping the routes of the Underground Railroad, and participating in an electronic simulation of life as a fugitive slave. (SM)

MapMaker and PathTracer for tracking carbon in genome-scale metabolic models

PubMed Central

Tervo, Christopher J.; Reed, Jennifer L.

2016-01-01

Constraint-based reconstruction and analysis (COBRA) modeling results can be difficult to interpret given the large numbers of reactions in genome-scale models. While paths in metabolic networks can be found, existing methods are not easily combined with constraint-based approaches. To address this limitation, two tools (MapMaker and PathTracer) were developed to find paths (including cycles) between metabolites, where each step transfers carbon from reactant to product. MapMaker predicts carbon transfer maps (CTMs) between metabolites using only information on molecular formulae and reaction stoichiometry, effectively determining which reactants and products share carbon atoms. MapMaker correctly assigned CTMs for over 97% of the 2,251 reactions in an Escherichia coli metabolic model (iJO1366). Using CTMs as inputs, PathTracer finds paths between two metabolites. PathTracer was applied to iJO1366 to investigate the importance of using CTMs and COBRA constraints when enumerating paths, to find active and high flux paths in flux balance analysis (FBA) solutions, to identify paths for putrescine utilization, and to elucidate a potential CO2 fixation pathway in E. coli. These results illustrate how MapMaker and PathTracer can be used in combination with constraint-based models to identify feasible, active, and high flux paths between metabolites. PMID:26771089

Aboveground to belowground herbivore defense signaling in maize: A two-way street?

USDA-ARS?s Scientific Manuscript database

Insect pests that attempt to feed on the caterpillar-resistant maize genotype Mp708 encounter a potent, multi-pronged defense system that thwarts their invasion. First, these plants are on “constant alert” due to constitutively elevated levels of the phytohormone jasmonic acid that signals the plan...

Studying Lords and Ladies, Arum Maculatum (L.)

ERIC Educational Resources Information Center

Jones, Derek H. T.

1977-01-01

Historical uses of Arum maculatum (L.) are summarized. Temperature changes during spadix maturation, spathe uncurling in the presence of flower tissue, indol-3-y1 acetic acid, and gibberellic acid are investigated in the laboratory. Dilute solutions of both phytohormones cause significant spathe uncurling. Further investigations are suggested.…

Bringing MapReduce Closer To Data With Active Drives

NASA Astrophysics Data System (ADS)

Golpayegani, N.; Prathapan, S.; Warmka, R.; Wyatt, B.; Halem, M.; Trantham, J. D.; Markey, C. A.

2017-12-01

Moving computation closer to the data location has been a much theorized improvement to computation for decades. The increase in processor performance, the decrease in processor size and power requirement combined with the increase in data intensive computing has created a push to move computation as close to data as possible. We will show the next logical step in this evolution in computing: moving computation directly to storage. Hypothetical systems, known as Active Drives, have been proposed as early as 1998. These Active Drives would have a general-purpose CPU on each disk allowing for computations to be performed on them without the need to transfer the data to the computer over the system bus or via a network. We will utilize Seagate's Active Drives to perform general purpose parallel computing using the MapReduce programming model directly on each drive. We will detail how the MapReduce programming model can be adapted to the Active Drive compute model to perform general purpose computing with comparable results to traditional MapReduce computations performed via Hadoop. We will show how an Active Drive based approach significantly reduces the amount of data leaving the drive when performing several common algorithms: subsetting and gridding. We will show that an Active Drive based design significantly improves data transfer speeds into and out of drives compared to Hadoop's HDFS while at the same time keeping comparable compute speeds as Hadoop.

A time-driven, activity-based costing methodology for determining the costs of red blood cell transfusion in patients with beta thalassaemia major.

PubMed

Burns, K E; Haysom, H E; Higgins, A M; Waters, N; Tahiri, R; Rushford, K; Dunstan, T; Saxby, K; Kaplan, Z; Chunilal, S; McQuilten, Z K; Wood, E M

2018-04-10

To describe the methodology to estimate the total cost of administration of a single unit of red blood cells (RBC) in adults with beta thalassaemia major in an Australian specialist haemoglobinopathy centre. Beta thalassaemia major is a genetic disorder of haemoglobin associated with multiple end-organ complications and typically requiring lifelong RBC transfusion therapy. New therapeutic agents are becoming available based on advances in understanding of the disorder and its consequences. Assessment of the true total cost of transfusion, incorporating both product and activity costs, is required in order to evaluate the benefits and costs of these new therapies. We describe the bottom-up, time-driven, activity-based costing methodology used to develop process maps to provide a step-by-step outline of the entire transfusion pathway. Detailed flowcharts for each process are described. Direct observations and timing of the process maps document all activities, resources, staff, equipment and consumables in detail. The analysis will include costs associated with performing these processes, including resources and consumables. Sensitivity analyses will be performed to determine the impact of different staffing levels, timings and probabilities associated with performing different tasks. Thirty-one process maps have been developed, with over 600 individual activities requiring multiple timings. These will be used for future detailed cost analyses. Detailed process maps using bottom-up, time-driven, activity-based costing for determining the cost of RBC transfusion in thalassaemia major have been developed. These could be adapted for wider use to understand and compare the costs and complexities of transfusion in other settings. © 2018 British Blood Transfusion Society.

Spatial patterns of high Aedes aegypti oviposition activity in northwestern Argentina.

PubMed

Estallo, Elizabet Lilia; Más, Guillermo; Vergara-Cid, Carolina; Lanfri, Mario Alberto; Ludueña-Almeida, Francisco; Scavuzzo, Carlos Marcelo; Introini, María Virginia; Zaidenberg, Mario; Almirón, Walter Ricardo

2013-01-01

In Argentina, dengue has affected mainly the Northern provinces, including Salta. The objective of this study was to analyze the spatial patterns of high Aedes aegypti oviposition activity in San Ramón de la Nueva Orán, northwestern Argentina. The location of clusters as hot spot areas should help control programs to identify priority areas and allocate their resources more effectively. Oviposition activity was detected in Orán City (Salta province) using ovitraps, weekly replaced (October 2005-2007). Spatial autocorrelation was measured with Moran's Index and depicted through cluster maps to identify hot spots. Total egg numbers were spatially interpolated and a classified map with Ae. aegypti high oviposition activity areas was performed. Potential breeding and resting (PBR) sites were geo-referenced. A logistic regression analysis of interpolated egg numbers and PBR location was performed to generate a predictive mapping of mosquito oviposition activity. Both cluster maps and predictive map were consistent, identifying in central and southern areas of the city high Ae. aegypti oviposition activity. A logistic regression model was successfully developed to predict Ae. aegypti oviposition activity based on distance to PBR sites, with tire dumps having the strongest association with mosquito oviposition activity. A predictive map reflecting probability of oviposition activity was produced. The predictive map delimitated an area of maximum probability of Ae. aegypti oviposition activity in the south of Orán city where tire dumps predominate. The overall fit of the model was acceptable (ROC=0.77), obtaining 99% of sensitivity and 75.29% of specificity. Distance to tire dumps is inversely associated with high mosquito activity, allowing us to identify hot spots. These methodologies are useful for prevention, surveillance, and control of tropical vector borne diseases and might assist National Health Ministry to focus resources more effectively.

Competition between isoprene emission and pigment synthesis during leaf development in aspen.

PubMed

Rasulov, Bahtijor; Bichele, Irina; Laisk, Agu; Niinemets, Ülo

2014-03-01

In growing leaves, lack of isoprene synthase (IspS) is considered responsible for delayed isoprene emission, but competition for dimethylallyl diphosphate (DMADP), the substrate for both isoprene synthesis and prenyltransferase reactions in photosynthetic pigment and phytohormone synthesis, can also play a role. We used a kinetic approach based on post-illumination isoprene decay and modelling DMADP consumption to estimate in vivo kinetic characteristics of IspS and prenyltransferase reactions, and to determine the share of DMADP use by different processes through leaf development in Populus tremula. Pigment synthesis rate was also estimated from pigment accumulation data and distribution of DMADP use from isoprene emission changes due to alendronate, a selective inhibitor of prenyltransferases. Development of photosynthetic activity and pigment synthesis occurred with the greatest rate in 1- to 5-day-old leaves when isoprene emission was absent. Isoprene emission commenced on days 5 and 6 and increased simultaneously with slowing down of pigment synthesis. In vivo Michaelis-Menten constant (Km ) values obtained were 265 nmol m(-2) (20 μm) for DMADP-consuming prenyltransferase reactions and 2560 nmol m(-2) (190 μm) for IspS. Thus, despite decelerating pigment synthesis reactions in maturing leaves, isoprene emission in young leaves was limited by both IspS activity and competition for DMADP by prenyltransferase reactions. © 2013 John Wiley & Sons Ltd.

Ethylene Inhibits Cell Proliferation of the Arabidopsis Root Meristem1[OPEN

PubMed Central

Street, Ian H.; Aman, Sitwat; Zubo, Yan; Ramzan, Aleena; Wang, Xiaomin; Shakeel, Samina N.; Kieber, Joseph J.; Schaller, G. Eric

2015-01-01

The root system of plants plays a critical role in plant growth and survival, with root growth being dependent on both cell proliferation and cell elongation. Multiple phytohormones interact to control root growth, including ethylene, which is primarily known for its role in controlling root cell elongation. We find that ethylene also negatively regulates cell proliferation at the root meristem of Arabidopsis (Arabidopsis thaliana). Genetic analysis indicates that the inhibition of cell proliferation involves two pathways operating downstream of the ethylene receptors. The major pathway is the canonical ethylene signal transduction pathway that incorporates CONSTITUTIVE TRIPLE RESPONSE1, ETHYLENE INSENSITIVE2, and the ETHYLENE INSENSITIVE3 family of transcription factors. The secondary pathway is a phosphorelay based on genetic analysis of receptor histidine kinase activity and mutants involving the type B response regulators. Analysis of ethylene-dependent gene expression and genetic analysis supports SHORT HYPOCOTYL2, a repressor of auxin signaling, as one mediator of the ethylene response and furthermore, indicates that SHORT HYPOCOTYL2 is a point of convergence for both ethylene and cytokinin in negatively regulating cell proliferation. Additional analysis indicates that ethylene signaling contributes but is not required for cytokinin to inhibit activity of the root meristem. These results identify key elements, along with points of cross talk with cytokinin and auxin, by which ethylene negatively regulates cell proliferation at the root apical meristem. PMID:26149574

Pavement cells: a model system for non-transcriptional auxin signalling and crosstalks.

PubMed

Chen, Jisheng; Wang, Fei; Zheng, Shiqin; Xu, Tongda; Yang, Zhenbiao

2015-08-01

Auxin (indole acetic acid) is a multifunctional phytohormone controlling various developmental patterns, morphogenetic processes, and growth behaviours in plants. The transcription-based pathway activated by the nuclear TRANSPORT INHIBITOR RESISTANT 1/auxin-related F-box auxin receptors is well established, but the long-sought molecular mechanisms of non-transcriptional auxin signalling remained enigmatic until very recently. Along with the establishment of the Arabidopsis leaf epidermal pavement cell (PC) as an exciting and amenable model system in the past decade, we began to gain insight into non-transcriptional auxin signalling. The puzzle-piece shape of PCs forms from intercalated or interdigitated cell growth, requiring local intra- and inter-cellular coordination of lobe and indent formation. Precise coordination of this interdigitated pattern requires auxin and an extracellular auxin sensing system that activates plasma membrane-associated Rho GTPases from plants and subsequent downstream events regulating cytoskeletal reorganization and PIN polarization. Apart from auxin, mechanical stress and cytokinin have been shown to affect PC interdigitation, possibly by interacting with auxin signals. This review focuses upon signalling mechanisms for cell polarity formation in PCs, with an emphasis on non-transcriptional auxin signalling in polarized cell expansion and pattern formation and how different auxin pathways interplay with each other and with other signals. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Methyl phenlactonoates are efficient strigolactone analogs with simple structure

PubMed Central

Jamil, Muhammad; Kountche, Boubacar A; Haider, Imran; Guo, Xiujie; Ntui, Valentine O; Jia, Kun-Peng; Hameed, Umar S; Nakamura, Hidemitsu; Lyu, Ying; Jiang, Kai; Hirabayashi, Kei; Tanokura, Masaru; Arold, Stefan T; Asami, Tadao

2018-01-01

abstract Strigolactones (SLs) are a new class of phytohormones that also act as germination stimulants for root parasitic plants, such as Striga spp., and as branching factors for symbiotic arbuscular mycorrhizal fungi. Sources for natural SLs are very limited. Hence, efficient and simple SL analogs are needed for elucidating SL-related biological processes as well as for agricultural applications. Based on the structure of the non-canonical SL methyl carlactonoate, we developed a new, easy to synthesize series of analogs, termed methyl phenlactonoates (MPs), evaluated their efficacy in exerting different SL functions, and determined their affinity for SL receptors from rice and Striga hermonthica. Most of the MPs showed considerable activity in regulating plant architecture, triggering leaf senescence, and inducing parasitic seed germination. Moreover, some MPs outperformed GR24, a widely used SL analog with a complex structure, in exerting particular SL functions, such as modulating Arabidopsis roots architecture and inhibiting rice tillering. Thus, MPs will help in elucidating the functions of SLs and are promising candidates for agricultural applications. Moreover, MPs demonstrate that slight structural modifications clearly impact the efficiency in exerting particular SL functions, indicating that structural diversity of natural SLs may mirror a functional specificity. PMID:29300919

High-resolution multibeam mapping and submersible surveys of topographic features in the northwestern Gulf of Mexico

USGS Publications Warehouse

Hickerson, E.L.; Schmahl, G.P.; Weaver, D.C.; Gardner, J.V.

2003-01-01

The Flower Garden Banks National Marine Sanctuary (FGBNMS) and the USGS Pacific Seafloor Mapping Project mapped about 2000 km2 of the northwestern Gulf of Mexico continental shelf during June 2002, using a Kongsberg Simrad EM1000 multibeam echosounder. Mapping focused on select topographic highs thave hae been idetnnfied as biological features warranting protection from oil and gas activities by the Minerals Management Service (MMS). The base maps will be used for all future ROV and submersible missions.

Intraoperative Functional Ultrasound Imaging of Human Brain Activity.

PubMed

Imbault, Marion; Chauvet, Dorian; Gennisson, Jean-Luc; Capelle, Laurent; Tanter, Mickael

2017-08-04

The functional mapping of brain activity is essential to perform optimal glioma surgery and to minimize the risk of postoperative deficits. We introduce a new, portable neuroimaging modality of the human brain based on functional ultrasound (fUS) for deep functional cortical mapping. Using plane-wave transmissions at an ultrafast frame rate (1 kHz), fUS is performed during surgery to measure transient changes in cerebral blood volume with a high spatiotemporal resolution (250 µm, 1 ms). fUS identifies, maps and differentiates regions of brain activation during task-evoked cortical responses within the depth of a sulcus in both awake and anaesthetized patients.

Mathemagenic Activities Program: [Reports from a Conference on New Perspectives in Developmental Assessment (1st, Athens, Georgia, November 15, 1972)].

ERIC Educational Resources Information Center

Smock, Charles D., Ed.; And Others

This set of four research reports is a product of the Mathemagenic Activities Program (MAP) for early childhood education of the University of Georgia Follow Through Program. Based on Piagetian theory, the MAP provides sequentially structured sets of curriculum materials and processes that are designed to continually challenge children in…

Trajectories of Attentional Development: An Exploration with the Master Activation Map Model

ERIC Educational Resources Information Center

Michael, George A.; Lete, Bernard; Ducrot, Stephanie

2013-01-01

The developmental trajectories of several attention components, such as orienting, inhibition, and the guidance of selection by relevance (i.e., advance knowledge relevant to the task) were investigated in 498 participants (ages 7, 8, 9, 10, 11, and 20). The paradigm was based on Michael et al.'s (2006) master activation map model and consisted of…

Differential accumulation of hyperforin and secohyperforin in Hypericum perforatum tissue cultures.

PubMed

Charchoglyan, Armen; Abrahamyan, Arusyak; Fujii, Isao; Boubakir, Zakia; Gulder, Tobias A M; Kutchan, Toni M; Vardapetyan, Hrachik; Bringmann, Gerhard; Ebizuka, Yutaka; Beerhues, Ludger

2007-11-01

Hyperforin is a pharmacologically active constituent of Hypericum perforatum (St. John's wort). In vitro cultures of this medicinal plant were found to contain hyperforin and three related polyprenylated acylphloroglucinol derivatives. The accumulation of these compounds was coupled to shoot regeneration, with secohyperforin being the major constituent in morphogenic cultures. The structure of secohyperforin was elucidated online by LC-DAD, -MS, and -NMR. In multiple shoot cultures, the ratio of hyperforin to secohyperforin was strongly influenced by the phytohormones N6-benzylaminopurine (BAP) and naphthalene-1-acetic acid (NAA). While increasing concentrations of BAP stimulated the formation of hyperforin, increasing concentrations of NAA elevated the level of secohyperforin. No differential stimulation was observed after elicitor treatment. Hyperforin and secohyperforin are proposed to arise from a branch point in the biosynthetic pathway.

36 CFR 1194.22 - Web-based intranet and internet information and applications.

Code of Federal Regulations, 2012 CFR

2012-07-01

... active region of a server-side image map. (f) Client-side image maps shall be provided instead of server-side image maps except where the regions cannot be defined with an available geometric shape. (g) Row...) Frames shall be titled with text that facilitates frame identification and navigation. (j) Pages shall be...

36 CFR 1194.22 - Web-based intranet and internet information and applications.

Code of Federal Regulations, 2014 CFR

2014-07-01

... active region of a server-side image map. (f) Client-side image maps shall be provided instead of server-side image maps except where the regions cannot be defined with an available geometric shape. (g) Row...) Frames shall be titled with text that facilitates frame identification and navigation. (j) Pages shall be...

36 CFR § 1194.22 - Web-based intranet and internet information and applications.

Code of Federal Regulations, 2013 CFR

2013-07-01

... active region of a server-side image map. (f) Client-side image maps shall be provided instead of server-side image maps except where the regions cannot be defined with an available geometric shape. (g) Row...) Frames shall be titled with text that facilitates frame identification and navigation. (j) Pages shall be...

Intrinsic optical signal imaging of the blood volume changes is sufficient for mapping the resting state functional connectivity in the rodent cortex.

PubMed

Kura, Sreekanth; Xie, Hongyu; Fu, Buyin; Ayata, Cenk; Boas, David A; Sakadžić, Sava

2018-06-01

Resting state functional connectivity (RSFC) allows the study of functional organization in normal and diseased brain by measuring the spontaneous brain activity generated under resting conditions. Intrinsic optical signal imaging (IOSI) based on multiple illumination wavelengths has been used successfully to compute RSFC maps in animal studies. The IOSI setup complexity would be greatly reduced if only a single wavelength can be used to obtain comparable RSFC maps. We used anesthetized mice and performed various comparisons between the RSFC maps based on single wavelength as well as oxy-, deoxy- and total hemoglobin concentration changes. The RSFC maps based on IOSI at a single wavelength selected for sensitivity to the blood volume changes are quantitatively comparable to the RSFC maps based on oxy- and total hemoglobin concentration changes obtained by the more complex IOSI setups. Moreover, RSFC maps do not require CCD cameras with very high frame acquisition rates, since our results demonstrate that they can be computed from the data obtained at frame rates as low as 5 Hz. Our results will have general utility for guiding future RSFC studies based on IOSI and making decisions about the IOSI system designs.

Activities for Plate Tectonics using GeoMapApp

NASA Astrophysics Data System (ADS)

Goodwillie, A. M.

2016-12-01

The concept of plate tectonics is a fundamental component of our understanding of how Earth works yet authentic, high-quality geoscience data related to plate tectonics may not be readily available to all students. To compound matters, when data is accessible, students may not possess the skills or resources necessary to explore and analyse it. As a result, much emphasis at federal and state level is now placed upon encouraging students to work with more data and more technology more often and more rigourously. Easy-to-use digital platforms offer much potential for promoting inquiry-based learning at all levels of education. GeoMapApp is one such tool. Developed at Columbia University's Lamont-Doherty Earth Observatory, GeoMapApp (http://www.geomapapp.org) is a free resource that integrates a wide range of research-grade geoscience data in one intuitive map-based interface. Simple strategies for data manipulation, visualisation and presentation allow uses to explore the data in meaningful ways. Layering and transparency capabilities further allow learners to use GeoMapApp to compare multiple data sets at once, and high-impact Save Session functionality allows a GeoMapApp project to be saved for sharing or later use. In this presentation, activities related to plate tectonics will be highlighted. One GeoMapApp activity helps students investigate plate boundaries by exploring earthquake and volcano locations. Another requires students to calculate the rate of seafloor spreading using crustal age data in various ocean basins. A third uses the GeoMapApp layering technique to explore the influence of geological forces in shaping the landscape. Each activity shown can be done by students on an individual basis, as pairs, or as groups. Educators report that student use of GeoMapApp fosters an increased sense of data "ownership" amongst students, promotes STEM skills, and provides them with access to authentic research-grade geoscience data using the same cutting-edge technological tool used by researchers.

ERECTA, salicylic acid, abscisic acid, and jasmonic acid modulate quantitative disease resistance of Arabidopsis thaliana to Verticillium longisporum.

PubMed

Häffner, Eva; Karlovsky, Petr; Splivallo, Richard; Traczewska, Anna; Diederichsen, Elke

2014-04-01

Verticillium longisporum is a soil-borne vascular pathogen infecting cruciferous hosts such as oilseed rape. Quantitative disease resistance (QDR) is the major control means, but its molecular basis is poorly understood so far. Quantitative trait locus (QTL) mapping was performed using a new (Bur×Ler) recombinant inbred line (RIL) population of Arabidopsis thaliana. Phytohormone measurements and analyses in defined mutants and near-isogenic lines (NILs) were used to identify genes and signalling pathways that underlie different resistance QTL. QTL for resistance to V. longisporum-induced stunting, systemic colonization by the fungus and for V. longisporum-induced chlorosis were identified. Stunting resistance QTL were contributed by both parents. The strongest stunting resistance QTL was shown to be identical with Erecta. A functional Erecta pathway, which was present in Bur, conferred partial resistance to V. longisporum-induced stunting. Bur showed severe stunting susceptibility in winter. Three stunting resistance QTL of Ler origin, two co-localising with wall-associated kinase-like (Wakl)-genes, were detected in winter. Furthermore, Bur showed a much stronger induction of salicylic acid (SA) by V. longisporum than Ler. Systemic colonization was controlled independently of stunting. The vec1 QTL on chromosome 2 had the strongest effect on systemic colonization. The same chromosomal region controlled the level of abscisic acid (ABA) and jasmonic acid (JA) in response to V. longisporum: The level of ABA was higher in colonization-susceptible Ler than in colonization-resistant Bur after V. longisporum infection. JA was down-regulated in Bur after infection, but not in Ler. These differences were also demonstrated in NILs, varying only in the region containing vec1. All phytohormone responses were shown to be independent of Erecta. Signalling systems with a hitherto unknown role in the QDR of A. thaliana against V. longisporum were identified: Erecta mediated resistance against V. longisporum-induced stunting. Independent of Erecta, stunting was caused in a light-dependent manner with possible participation of SA and Wakl genes. ABA and JA showed a genotype-specific response that corresponded with systemic colonization by the fungus. Understanding the biological basis of phenotypic variation in A. thaliana with respect to V. longisporum resistance will provide new approaches for implementing durable resistance in cruciferous crops.

Diuretics Prime Plant Immunity in Arabidopsis thaliana

PubMed Central

Noutoshi, Yoshiteru; Ikeda, Mika; Shirasu, Ken

2012-01-01

Plant activators are agrochemicals that activate the plant immune system, thereby enhancing disease resistance. Due to their prophylactic and durable effects on a wide spectrum of diseases, plant activators can provide synergistic crop protection when used in combination with traditional pest controls. Although plant activators have achieved great success in wet-rice farming practices in Asia, their use is still limited. To isolate novel plant activators applicable to other crops, we screened a chemical library using a method that can selectively identify immune-priming compounds. Here, we report the isolation and characterization of three diuretics, bumetanide, bendroflumethiazide and clopamide, as immune-priming compounds. These drugs upregulate the immunity-related cell death of Arabidopsis suspension-cultured cells induced with an avirulent strain of Pseudomonas syringae pv. tomato in a concentration-dependent manner. The application of these compounds to Arabidopsis plants confers disease resistance to not only the avirulent but also a virulent strain of the pathogen. Unlike salicylic acid, an endogenous phytohormone that governs disease resistance in response to biotrophic pathogens, the three diuretic compounds analyzed here do not induce PR1 or inhibit plant growth, showing potential as lead compounds in a practical application. PMID:23144763

Active edge maps for medical image registration

NASA Astrophysics Data System (ADS)

Kerwin, William; Yuan, Chun

2001-07-01

Applying edge detection prior to performing image registration yields several advantages over raw intensity- based registration. Advantages include the ability to register multicontrast or multimodality images, immunity to intensity variations, and the potential for computationally efficient algorithms. In this work, a common framework for edge-based image registration is formulated as an adaptation of snakes used in boundary detection. Called active edge maps, the new formulation finds a one-to-one transformation T(x) that maps points in a source image to corresponding locations in a target image using an energy minimization approach. The energy consists of an image component that is small when edge features are well matched in the two images, and an internal term that restricts T(x) to allowable configurations. The active edge map formulation is illustrated here with a specific example developed for affine registration of carotid artery magnetic resonance images. In this example, edges are identified using a magnitude of gradient operator, image energy is determined using a Gaussian weighted distance function, and the internal energy includes separate, adjustable components that control volume preservation and rigidity.

Geographic Information Technologies as an outreach activity in geo-scientific education

NASA Astrophysics Data System (ADS)

Maman, Shimrit; Isaacson, Sivan; Blumberg, Dan G.

2016-04-01

In recent years, a decline in the rates of examinees in the academic track that were entitled to an enhanced matriculation certificate in scientific-technological education was reported in Israel. To confront this problem the Earth and Planetary Image Facility (EPIF) at Ben-Gurion University of the Negev fosters interdisciplinary exploration through educational programs that make use of the facility and its equipment and enable the empowerment of the community by understanding and appreciating science and technology. This is achieved by using Geographic Information Technologies (GIT) such as remote sensing and Geographical Information Systems (GIS) for geo-physical sciences in activities that combine theoretical background with hands-on activities. Monitoring Earth from space by satellites, digital atlases and virtual-based positioning applications are examples for fusion of spatial information (geographic) and technology that the activity is based on. GIT opens a new chapter and a recent history of Cartography starting from the collection of spatial data to its presentation and analysis. GIS have replaced the use of classical atlas books and offer a variety of Web-based applications that provide maps and display up-to-date imagery. The purpose of this workshop is to expose teachers and students to GITs which are applicable in every classroom. The activity imparts free geographic information systems that exist in cyberspace and accessible to single users as the Israeli national GIS and Google earth, which are based on a spatial data and long term local and global satellite imagery coverage. In this paper, our "Think global-Map Local" activity is presented. The activity uses GIS and change detection technologies as means to encourage students to explore environmental issues both around the globe and close to their surroundings. The students detect changes by comparing multi temporal images of a chosen site and learn how to map the alterations and produce change detection maps with simple and user friendly tools. The activity is offered both for students and supervised projects for teachers and youth.

A Comparative Study of the Effects of a Concept Mapping Enhanced Laboratory Experience on Turkish High School Students' Understanding of Acid-Base Chemistry

ERIC Educational Resources Information Center

Ozmen, Haluk; Demircioglu, Gokhan; Coll, Richard K.

2009-01-01

The research reported here consists of the introduction of an intervention based on a series of laboratory activities combined with concept mapping. The purpose of this intervention was to enhance student understanding of acid-base chemistry for tenth grade students' from two classes in a Turkish high school. An additional aim was to enhance…

From blood oxygenation level dependent (BOLD) signals to brain temperature maps.

PubMed

Sotero, Roberto C; Iturria-Medina, Yasser

2011-11-01

A theoretical framework is presented for converting Blood Oxygenation Level Dependent (BOLD) images to brain temperature maps, based on the idea that disproportional local changes in cerebral blood flow (CBF) as compared with cerebral metabolic rate of oxygen consumption (CMRO₂) during functional brain activity, lead to both brain temperature changes and the BOLD effect. Using an oxygen limitation model and a BOLD signal model, we obtain a transcendental equation relating CBF and CMRO₂ changes with the corresponding BOLD signal, which is solved in terms of the Lambert W function. Inserting this result in the dynamic bioheat equation describing the rate of temperature changes in the brain, we obtain a nonautonomous ordinary differential equation that depends on the BOLD response, which is solved numerically for each brain voxel. Temperature maps obtained from a real BOLD dataset registered in an attention to visual motion experiment were calculated, obtaining temperature variations in the range: (-0.15, 0.1) which is consistent with experimental results. The statistical analysis revealed that significant temperature activations have a similar distribution pattern than BOLD activations. An interesting difference was the activation of the precuneus in temperature maps, a region involved in visuospatial processing, an effect that was not observed on BOLD maps. Furthermore, temperature maps were more localized to gray matter regions than the original BOLD maps, showing less activated voxels in white matter and cerebrospinal fluid.

Effect of the Winter Wheat Cheyenne 5A Substituted Chromosome on Dynamics of Abscisic Acid and Cytokinins in Freezing-Sensitive Chinese Spring Genetic Background

PubMed Central

Kalapos, Balázs; Novák, Aliz; Dobrev, Petre; Vítámvás, Pavel; Marincs, Ferenc; Galiba, Gábor; Vanková, Radomira

2017-01-01

The effect of short- and long-term cold treatment on the abscisic acid (ABA) and cytokinin (CK) metabolism, and their main biosynthesis- and signaling-related genes were investigated in freezing-sensitive and freezing-tolerant wheat genotypes. Varieties Cheyenne and Chinese Spring substituted with the 5A Cheyenne chromosome, which represented freezing-tolerant genotypes, were compared with the freezing-sensitive Chinese Spring. Hormone levels and gene expression data indicated that the short- and long-term cold treatments are associated with specific regulation of the accumulation of cold-protective proteins and phytohormone levels, as well as the expression profiles of the hormone-related genes. The significant differences were observed between the genotypes, and between their leaf and crown tissues, too. The level of dehydrins, including WCS120 protein, and expression of WCS120 gene were considerably higher in the freezing-tolerant genotypes after 21 days of cold treatment. Expression of Cor14b and CBF14, cold-responsive regulator genes, was increased by cold treatment in all genotypes, to higher extent in freezing-tolerant genotypes. Cluster analysis revealed that the tolerant genotypes had a similar response to cold treatment, regarding expression of the ABA and CK metabolic genes, as well as hormone levels in leaves. As far as hormone levels in crowns are concerned, however, the strongly freezing-tolerant Cheyenne variety clustered separately from the Chinese Spring and the substitution line, which were more similar to each other after both 1 and 21 days of cold treatment than to Cheyenne. Based on these results we concluded that the 5A chromosome of wheat might have both a direct and an indirect impact on the phytohormone-dependent cold-induced freezing tolerance. Based on the gene expression data, novel genetic markers could be developed, which may be used to determine the freezing tolerance level in a wide range of wheat varieties. PMID:29238355

Evaluation of LiDAR Imagery as a Tool for Mapping the Northern San Andreas Fault in Heavily Forested Areas of Mendocino and Sonoma Counties, California

NASA Astrophysics Data System (ADS)

Prentice, C. S.; Koehler, R. D.; Baldwin, J. N.; Harding, D. J.

2004-12-01

We are mapping in detail active traces of the San Andreas Fault in Mendocino and Sonoma Counties in northern California, using recently acquired airborne LiDAR (also known as ALSM) data. The LiDAR data set provides a powerful new tool for mapping geomorphic features related to the San Andreas Fault because it can be used to produce high-resolution images of the ground surfaces beneath the forest canopy along the 70-km-long section of the fault zone encompassed by the data. Our effort represents the first use of LiDAR data to map active fault traces in a densely vegetated region along the San Andreas Fault. We are using shaded relief images generated from bare-earth DEMs to conduct detailed mapping of fault-related geomorphic features (e.g. scarps, offset streams, linear valleys, shutter ridges, and sag ponds) between Fort Ross and Point Arena. Initially, we map fault traces digitally, on-screen, based only on the geomorphology interpreted from LiDAR images. We then conduct field reconnaissance using the initial computer-based maps in order to verify and further refine our mapping. We found that field reconnaissance is of utmost importance in producing an accurate and detailed map of fault traces. Many lineaments identified as faults from the on-screen images were determined in the field to be old logging roads or other features unrelated to faulting. Also, in areas where the resolution of LiDAR data is poor, field reconnaissance, coupled with topographic maps and aerial photographs, permits a more accurate location of fault-related geomorphic features. LiDAR images are extremely valuable as a base for field mapping in this heavily forested area, and the use of LiDAR is far superior to traditional mapping techniques relying only on aerial photography and 7.5 minute USGS quadrangle topographic maps. Comparison with earlier mapping of the northern San Andreas fault (Brown and Wolfe, 1972) shows that in some areas the LiDAR data allow a correction of the fault trace location of up to several hundred meters. To date we have field checked approximately 24 km of the 70-km-long section of the fault for which LiDAR data is available. The remaining 46 km will be field checked in 2005. The result will be a much more accurate map of the active traces of the northern San Andreas Fault, which will be of great use for future fault studies.

Ethylene contributes to mir1-mediated maize defense against the phloem-sap sucking insect Rhopalosiphum maidis.

USDA-ARS?s Scientific Manuscript database

Signaling networks among multiple phytohormones fine-tune plant defense responses to insect herbivore attack. Previously, it was reported that the synergistic combination of ethylene (ET) and jasmonic acid (JA) was required for providing maize insect resistance1 (mir1), a key endogenous defense sign...

Comparison of phytohormone levels and transcript profiles during seasonal dormancy transitions in underground adventitious buds of leafy spurge

USDA-ARS?s Scientific Manuscript database

Leafy spurge (Euphorbia esula L.) is an herbaceous perennial weed that maintains its perennial growth habit through generation of underground adventitious buds (UABs) on the crown and lateral roots. These UABs undergo seasonal phases of dormancy under natural conditions, namely para-, endo-, and eco...

Accumulation of high OPDA level correlates with reduced ROS and elevated GSH benefiting white cell survival in variegated leaves

USDA-ARS?s Scientific Manuscript database

Variegated Epipremnum aureum ‘Marble Queen’ plant has white (VMW) and green (VMG) sectors within the same leaf. The white sector cells containing undifferentiated chloroplasts are viable, but the underlying mechanism for their survival is not clear. Because phytohormones are important for plant grow...

EFFECTS OF MEDIUM COMPONENTS AND PHYTOHORMONES ON IN VITRO FROND PROLIFERATOIN OF LEMNA GIBBA G3 AND 24 ADDITIONAL LEMNA GIBBA STRAINS. (R823570)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Exogenous salicylic acid enhances the resistance of wheat seedlings to hessian fly (Diptera: Cecidomyiidae) infestation under heat stress

USDA-ARS?s Scientific Manuscript database

Heat stress exerts significant impact on plant-parasite interactions. Phytohormones, such as salicylic acid (SA) play important roles in plant defense against parasite attacks. Here we studied the impact of a combination of heat stress and exogenous SA on wheat (Triticum aestivum L.) plant resistanc...

Inviting Argument by Analogy: Analogical-Mapping-Based Comparison Activities as a Scaffold for Small-Group Argumentation

ERIC Educational Resources Information Center

Emig, Brandon R.; McDonald, Scott; Zembal-Saul, Carla; Strauss, Susan G.

2014-01-01

This study invited small groups to make several arguments by analogy about simple machines. Groups were first provided training on analogical (structure) mapping and were then invited to use analogical mapping as a scaffold to make arguments. In making these arguments, groups were asked to consider three simple machines: two machines that they had…

Abscisic Acid and Abiotic Stress Tolerance in Crop Plants

PubMed Central

Sah, Saroj K.; Reddy, Kambham R.; Li, Jiaxu

2016-01-01

Abiotic stress is a primary threat to fulfill the demand of agricultural production to feed the world in coming decades. Plants reduce growth and development process during stress conditions, which ultimately affect the yield. In stress conditions, plants develop various stress mechanism to face the magnitude of stress challenges, although that is not enough to protect them. Therefore, many strategies have been used to produce abiotic stress tolerance crop plants, among them, abscisic acid (ABA) phytohormone engineering could be one of the methods of choice. ABA is an isoprenoid phytohormone, which regulates various physiological processes ranging from stomatal opening to protein storage and provides adaptation to many stresses like drought, salt, and cold stresses. ABA is also called an important messenger that acts as the signaling mediator for regulating the adaptive response of plants to different environmental stress conditions. In this review, we will discuss the role of ABA in response to abiotic stress at the molecular level and ABA signaling. The review also deals with the effect of ABA in respect to gene expression. PMID:27200044

Phytotoxical effect of Lepidium draba L. extracts on the germination and growth of monocot (Zea mays L.) and dicot (Amaranthus retroflexus L.) seeds.

PubMed

Kaya, Yusuf; Aksakal, Ozkan; Sunar, Serap; Erturk, Filiz Aygun; Bozari, Sedat; Agar, Guleray; Erez, Mehmet Emre; Battal, Peyami

2015-03-01

Laboratory experiments were performed to determine phytotoxic potentials of white top (Lepidium draba) methanol extracts (root, stem and leaf) on germination and early growth of corn (Zea mays) and redroot pigweed (Amaranthus retroflexus). Furthermore, the effects of different methanol extracts of L. draba on the phytohormone (indole-3-acetic acid (IAA), gibberellic acid (GA), abscisic acid (ABA) and zeatin) levels of corn and redroot pigweed were investigated. It was observed that all concentrations of methanol extracts of root, stem and leaf of L. draba inhibited germination, radicle and plumule elongation when compared with the respective controls. Besides this, the degree of inhibition was increased in concert with increasing concentrations of extracts used. On the other hand, phytohormone levels changed with the application of different extract concentrations. Comparing with the control, the GA levels significantly decreased while the ABA levels increased in all the application groups. Zeatin and IAA levels showed changes depending upon the applied extracts and concentrations. © The Author(s) 2012.

Cortical connective field estimates from resting state fMRI activity.

PubMed

Gravel, Nicolás; Harvey, Ben; Nordhjem, Barbara; Haak, Koen V; Dumoulin, Serge O; Renken, Remco; Curčić-Blake, Branislava; Cornelissen, Frans W

2014-01-01

One way to study connectivity in visual cortical areas is by examining spontaneous neural activity. In the absence of visual input, such activity remains shaped by the underlying neural architecture and, presumably, may still reflect visuotopic organization. Here, we applied population connective field (CF) modeling to estimate the spatial profile of functional connectivity in the early visual cortex during resting state functional magnetic resonance imaging (RS-fMRI). This model-based analysis estimates the spatial integration between blood-oxygen level dependent (BOLD) signals in distinct cortical visual field maps using fMRI. Just as population receptive field (pRF) mapping predicts the collective neural activity in a voxel as a function of response selectivity to stimulus position in visual space, CF modeling predicts the activity of voxels in one visual area as a function of the aggregate activity in voxels in another visual area. In combination with pRF mapping, CF locations on the cortical surface can be interpreted in visual space, thus enabling reconstruction of visuotopic maps from resting state data. We demonstrate that V1 ➤ V2 and V1 ➤ V3 CF maps estimated from resting state fMRI data show visuotopic organization. Therefore, we conclude that-despite some variability in CF estimates between RS scans-neural properties such as CF maps and CF size can be derived from resting state data.

DEG9, a serine protease, modulates cytokinin and light signaling by regulating the level of ARABIDOPSIS RESPONSE REGULATOR 4.

PubMed

Chi, Wei; Li, Jing; He, Baoye; Chai, Xin; Xu, Xiumei; Sun, Xuwu; Jiang, Jingjing; Feng, Peiqiang; Zuo, Jianru; Lin, Rongcheng; Rochaix, Jean-David; Zhang, Lixin

2016-06-21

Cytokinin is an essential phytohormone that controls various biological processes in plants. A number of response regulators are known to be important for cytokinin signal transduction. ARABIDOPSIS RESPONSE REGULATOR 4 (ARR4) mediates the cross-talk between light and cytokinin signaling through modulation of the activity of phytochrome B. However, the mechanism that regulates the activity and stability of ARR4 is unknown. Here we identify an ATP-independent serine protease, degradation of periplasmic proteins 9 (DEG9), which localizes to the nucleus and regulates the stability of ARR4. Biochemical evidence shows that DEG9 interacts with ARR4, thereby targeting ARR4 for degradation, which suggests that DEG9 regulates the stability of ARR4. Moreover, genetic evidence shows that DEG9 acts upstream of ARR4 and regulates the activity of ARR4 in cytokinin and light-signaling pathways. This study thus identifies a role for a ubiquitin-independent selective protein proteolysis in the regulation of the stability of plant signaling components.

Overexpression of EsMcsu1 from the halophytic plant Eutrema salsugineum promotes abscisic acid biosynthesis and increases drought resistance in alfalfa (Medicago sativa L.).

PubMed

Zhou, C; Ma, Z Y; Zhu, L; Guo, J S; Zhu, J; Wang, J F

2015-12-17

The stress phytohormone abscisic acid (ABA) plays pivotal roles in plants' adaptive responses to adverse environments. Molybdenum cofactor sulfurases influence aldehyde oxidase activity and ABA biosynthesis. In this study, we isolated a novel EsMcsu1 gene encoding a molybdenum cofactor sulfurase from Eutrema salsugineum. EsMcus1 transcriptional patterns varied between organs, and its expression was significantly upregulated by abiotic stress or ABA treatment. Alfalfa plants that overexpressed EsMcsu1 had a higher ABA content than wild-type (WT) plants under drought stress conditions. Furthermore, levels of reactive oxygen species (ROS), ion leakage, and malondialdehyde were lower in the transgenic plants than in the WT plants after drought treatment, suggesting that the transgenic plants experienced less ROS-mediated damage. However, the expression of several stress-responsive genes, antioxidant enzyme activity, and osmolyte (proline and total soluble sugar) levels in the transgenic plants were higher than those in the WT plants after drought treatment. Therefore, EsMcsu1 overexpression improved drought tolerance in alfalfa plants by activating a series of ABA-mediated stress responses.

Genetic engineering of cytokinin metabolism: prospective way to improve agricultural traits of crop plants.

PubMed

Zalabák, David; Pospíšilová, Hana; Šmehilová, Mária; Mrízová, Katarína; Frébort, Ivo; Galuszka, Petr

2013-01-01

Cytokinins (CKs) are ubiquitous phytohormones that participate in development, morphogenesis and many physiological processes throughout plant kingdom. In higher plants, mutants and transgenic cells and tissues with altered activity of CK metabolic enzymes or perception machinery, have highlighted their crucial involvement in different agriculturally important traits, such as productivity, increased tolerance to various stresses and overall plant morphology. Furthermore, recent precise metabolomic analyses have elucidated the specific occurrence and distinct functions of different CK types in various plant species. Thus, smooth manipulation of active CK levels in a spatial and temporal way could be a very potent tool for plant biotechnology in the future. This review summarises recent advances in cytokinin research ranging from transgenic alteration of CK biosynthetic, degradation and glucosylation activities and CK perception to detailed elucidation of molecular processes, in which CKs work as a trigger in model plants. The first attempts to improve the quality of crop plants, focused on cereals are discussed, together with proposed mechanism of action of the responses involved. Copyright © 2011 Elsevier Inc. All rights reserved.

Conformational dynamics underlie the activity of the auxin-binding protein, Nt-abp1.

PubMed

David, K; Carnero-Diaz, E; Leblanc, N; Monestiez, M; Grosclaude, J; Perrot-Rechenmann, C

2001-09-14

The auxin-binding protein 1 (ABP1) has been proposed to be involved in the perception of the phytohormone at the plasma membrane. Site-directed mutagenesis was performed on highly conserved residues at the C terminus of ABP1 to investigate their relative importance in protein folding and activation of a functional response at the plasma membrane. Detailed analysis of the dynamic interaction of the wild-type ABP1 and mutated proteins with three distinct monoclonal antibodies recognizing conformation-dependent epitopes was performed by surface plasmon resonance. The influence of auxin on these interactions was also investigated. The Cys(177) as well as Asp(175) and Glu(176) were identified as critical residues for ABP1 folding and action at the plasma membrane. On the contrary, the C-terminal KDEL sequence was demonstrated not to be essential for auxin binding, interaction with the plasma membrane, or activation of the transduction cascade although it does appear to be involved in the stability of ABP1. Taken together, the results confirmed that ABP1 conformational change is the critical step for initiating the signal from the plasma membrane.

Mapping cell-specific functional connections in the mouse brain using ChR2-evoked hemodynamics (Conference Presentation)

NASA Astrophysics Data System (ADS)

Bauer, Adam Q.; Kraft, Andrew; Baxter, Grant A.; Bruchas, Michael; Lee, Jin-Moo; Culver, Joseph P.

2017-02-01

Functional magnetic resonance imaging (fMRI) has transformed our understanding of the brain's functional organization. However, mapping subunits of a functional network using hemoglobin alone presents several disadvantages. Evoked and spontaneous hemodynamic fluctuations reflect ensemble activity from several populations of neurons making it difficult to discern excitatory vs inhibitory network activity. Still, blood-based methods of brain mapping remain powerful because hemoglobin provides endogenous contrast in all mammalian brains. To add greater specificity to hemoglobin assays, we integrated optical intrinsic signal(OIS) imaging with optogenetic stimulation to create an Opto-OIS mapping tool that combines the cell-specificity of optogenetics with label-free, hemoglobin imaging. Before mapping, titrated photostimuli determined which stimulus parameters elicited linear hemodynamic responses in the cortex. Optimized stimuli were then scanned over the left hemisphere to create a set of optogenetically-defined effective connectivity (Opto-EC) maps. For many sites investigated, Opto-EC maps exhibited higher spatial specificity than those determined using spontaneous hemodynamic fluctuations. For example, resting-state functional connectivity (RS-FC) patterns exhibited widespread ipsilateral connectivity while Opto-EC maps contained distinct short- and long-range constellations of ipsilateral connectivity. Further, RS-FC maps were usually symmetric about midline while Opto-EC maps displayed more heterogeneous contralateral homotopic connectivity. Both Opto-EC and RS-FC patterns were compared to mouse connectivity data from the Allen Institute. Unlike RS-FC maps, Thy1-based maps collected in awake, behaving mice closely recapitulated the connectivity structure derived using ex vivo anatomical tracer methods. Opto-OIS mapping could be a powerful tool for understanding cellular and molecular contributions to network dynamics and processing in the mouse brain.

Small RNA Regulators of Plant-Hemipteran Interactions: Micromanagers with Versatile Roles

PubMed Central

Sattar, Sampurna; Thompson, Gary A.

2016-01-01

Non-coding small RNAs (sRNAs) in plants have important roles in regulating biological processes, including development, reproduction, and stress responses. Recent research indicates significant roles for sRNA-mediated gene silencing during plant-hemipteran interactions that involve all three of these biological processes. Plant responses to hemipteran feeding are determined by changes in the host transcriptome that appear to be fine-tuned by sRNAs. The role of sRNA in plant defense responses is complex. Different forms of sRNAs, with specific modes of action, regulate changes in the host transcriptome primarily through post-transcriptional gene silencing and occasionally through translational repression. Plant genetic resistance against hemipterans provides a model to explore the regulatory roles of sRNAs in plant defense. Aphid-induced sRNA expression in resistance genotypes delivers a new paradigm in understanding the regulation of R gene-mediated resistance in host plants. Unique sRNA profiles, including changes in sRNA biogenesis and expression can also provide insights into susceptibility to insect herbivores. Activation of phytohormone-mediated defense responses against insect herbivory is another hallmark of this interaction, and recent studies have shown that regulation of phytohormone signaling is under the control of sRNAs. Hemipterans feeding on resistant plants also show changes in insect sRNA profiles, possibly influencing insect development and reproduction. Changes in insect traits such as fecundity, host range, and resistance to insecticides are impacted by sRNAs and can directly contribute to the success of certain insect biotypes. In addition to causing direct damage to the host plant, hemipteran insects are often vectors of viral pathogens. Insect anti-viral RNAi machinery is activated to limit virus accumulation, suggesting a role in insect immunity. Virus-derived long sRNAs strongly resemble insect piRNAs, leading to the speculation that the piRNA pathway is induced in response to viral infection. Evidence for robust insect RNAi machinery in several hemipteran species is of immense interest and is being actively pursued as a possible tool for insect control. RNAi-induced gene silencing following uptake of exogenous dsRNA was successfully demonstrated in several hemipterans and the presence of sid-1 like genes support the concept of a systemic response in some species. PMID:27625654

Black leaf streak disease affects starch metabolism in banana fruit.

PubMed

Saraiva, Lorenzo de Amorim; Castelan, Florence Polegato; Shitakubo, Renata; Hassimotto, Neuza Mariko Aymoto; Purgatto, Eduardo; Chillet, Marc; Cordenunsi, Beatriz Rosana

2013-06-12

Black leaf streak disease (BLSD), also known as black sigatoka, represents the main foliar disease in Brazilian banana plantations. In addition to photosynthetic leaf area losses and yield losses, this disease causes an alteration in the pre- and postharvest behavior of the fruit. The aim of this work was to investigate the starch metabolism of fruits during fruit ripening from plants infected with BLSD by evaluating carbohydrate content (i.e., starch, soluble sugars, oligosaccharides, amylose), phenolic compound content, phytohormones, enzymatic activities (i.e., starch phosphorylases, α- and β-amylase), and starch granules. The results indicated that the starch metabolism in banana fruit ripening is affected by BLSD infection. Fruit from infested plots contained unusual amounts of soluble sugars in the green stage and smaller starch granules and showed a different pattern of superficial degradation. Enzymatic activities linked to starch degradation were also altered by the disease. Moreover, the levels of indole-acetic acid and phenolic compounds indicated an advanced fruit physiological age for fruits from infested plots.

The N-end rule pathway regulates pathogen responses in plants

PubMed Central

de Marchi, Rémi; Sorel, Maud; Mooney, Brian; Fudal, Isabelle; Goslin, Kevin; Kwaśniewska, Kamila; Ryan, Patrick T.; Pfalz, Marina; Kroymann, Juergen; Pollmann, Stephan; Feechan, Angela; Wellmer, Frank; Rivas, Susana; Graciet, Emmanuelle

2016-01-01

To efficiently counteract pathogens, plants rely on a complex set of immune responses that are tightly regulated to allow the timely activation, appropriate duration and adequate amplitude of defense programs. The coordination of the plant immune response is known to require the activity of the ubiquitin/proteasome system, which controls the stability of proteins in eukaryotes. Here, we demonstrate that the N-end rule pathway, a subset of the ubiquitin/proteasome system, regulates the defense against a wide range of bacterial and fungal pathogens in the model plant Arabidopsis thaliana. We show that this pathway positively regulates the biosynthesis of plant-defense metabolites such as glucosinolates, as well as the biosynthesis and response to the phytohormone jasmonic acid, which plays a key role in plant immunity. Our results also suggest that the arginylation branch of the N-end rule pathway regulates the timing and amplitude of the defense program against the model pathogen Pseudomonas syringae AvrRpm1. PMID:27173012

Prioritizing plant defence over growth through WRKY regulation facilitates infestation by non-target herbivores.

PubMed

Li, Ran; Zhang, Jin; Li, Jiancai; Zhou, Guoxin; Wang, Qi; Bian, Wenbo; Erb, Matthias; Lou, Yonggen

2015-06-17

Plants generally respond to herbivore attack by increasing resistance and decreasing growth. This prioritization is achieved through the regulation of phytohormonal signaling networks. However, it remains unknown how this prioritization affects resistance against non-target herbivores. In this study, we identify WRKY70 as a specific herbivore-induced, mitogen-activated protein kinase-regulated rice transcription factor that physically interacts with W-box motives and prioritizes defence over growth by positively regulating jasmonic acid (JA) and negatively regulating gibberellin (GA) biosynthesis upon attack by the chewing herbivore Chilo suppressalis. WRKY70-dependent JA biosynthesis is required for proteinase inhibitor activation and resistance against C. suppressalis. In contrast, WRKY70 induction increases plant susceptibility against the rice brown planthopper Nilaparvata lugens. Experiments with GA-deficient rice lines identify WRKY70-dependent GA signaling as the causal factor in N. lugens susceptibility. Our study shows that prioritizing defence over growth leads to a significant resistance trade-off with important implications for the evolution and agricultural exploitation of plant immunity.

Energy Spectral Behaviors of Communication Networks of Open-Source Communities

PubMed Central

Yang, Jianmei; Yang, Huijie; Liao, Hao; Wang, Jiangtao; Zeng, Jinqun

2015-01-01

Large-scale online collaborative production activities in open-source communities must be accompanied by large-scale communication activities. Nowadays, the production activities of open-source communities, especially their communication activities, have been more and more concerned. Take CodePlex C # community for example, this paper constructs the complex network models of 12 periods of communication structures of the community based on real data; then discusses the basic concepts of quantum mapping of complex networks, and points out that the purpose of the mapping is to study the structures of complex networks according to the idea of quantum mechanism in studying the structures of large molecules; finally, according to this idea, analyzes and compares the fractal features of the spectra in different quantum mappings of the networks, and concludes that there are multiple self-similarity and criticality in the communication structures of the community. In addition, this paper discusses the insights and application conditions of different quantum mappings in revealing the characteristics of the structures. The proposed quantum mapping method can also be applied to the structural studies of other large-scale organizations. PMID:26047331

NHS-Esters As Versatile Reactivity-Based Probes for Mapping Proteome-Wide Ligandable Hotspots.

PubMed

Ward, Carl C; Kleinman, Jordan I; Nomura, Daniel K

2017-06-16

Most of the proteome is considered undruggable, oftentimes hindering translational efforts for drug discovery. Identifying previously unknown druggable hotspots in proteins would enable strategies for pharmacologically interrogating these sites with small molecules. Activity-based protein profiling (ABPP) has arisen as a powerful chemoproteomic strategy that uses reactivity-based chemical probes to map reactive, functional, and ligandable hotspots in complex proteomes, which has enabled inhibitor discovery against various therapeutic protein targets. Here, we report an alkyne-functionalized N-hydroxysuccinimide-ester (NHS-ester) as a versatile reactivity-based probe for mapping the reactivity of a wide range of nucleophilic ligandable hotspots, including lysines, serines, threonines, and tyrosines, encompassing active sites, allosteric sites, post-translational modification sites, protein interaction sites, and previously uncharacterized potential binding sites. Surprisingly, we also show that fragment-based NHS-ester ligands can be made to confer selectivity for specific lysine hotspots on specific targets including Dpyd, Aldh2, and Gstt1. We thus put forth NHS-esters as promising reactivity-based probes and chemical scaffolds for covalent ligand discovery.

Recently Active Traces of the Berryessa Fault, California: A Digital Database

USGS Publications Warehouse

Lienkaemper, James J.

2012-01-01

The purpose of this map is to show the location of and evidence for recent movement on active fault traces within the Berryessa section and parts of adjacent sections of the Green Valley Fault Zone, California. The location and recency of the mapped traces is primarily based on geomorphic expression of the fault as interpreted from large-scale 2010 aerial photography and from 2007 and 2011 0.5 and 1.0 meter bare-earth LiDAR imagery (that is, high-resolution topographic data). In a few places, evidence of fault creep and offset Holocene strata in trenches and natural exposures have confirmed the activity of some of these traces. This publication is formatted both as a digital database for use within a geographic information system (GIS) and for broader public access as map images that may be browsed on-line or download a summary map. The report text describes the types of scientific observations used to make the map, gives references pertaining to the fault and the evidence of faulting, and provides guidance for use of and limitations of the map.

Immunolocalization of IAA and ABA in roots and needles of radiata pine (Pinus radiata) during drought and rewatering.

PubMed

De Diego, N; Rodríguez, J L; Dodd, I C; Pérez-Alfocea, F; Moncaleán, P; Lacuesta, M

2013-05-01

Anatomical, physiological and phytohormonal changes involved in drought tolerance were examined in different Pinus radiata D. Don breeds subjected to soil drying and rewatering. Breeds with the smallest stomatal chamber size had the lowest transpiration rate and the highest intrinsic water-use efficiency. Xylem cell size was positively correlated with leaf hydraulic conductance and needle indole-3-acetic acid (IAA) concentrations, whereas transpiration rate was negatively correlated with needle abscisic acid (ABA) levels. Since these two phytohormones seem important in regulating the P. radiata drought response, they were simultaneously immunolocalized in roots and needles of the most tolerant breed (P. radiata var. radiata × var. cedrosensis) during two sequential drought cycles and after rewatering. During drought, IAA was unequally distributed into the pointed area of the needle cross-section and mainly located in mesophyll and vascular tissue cells of needles, possibly inducing needle epinasty, whereas ABA was principally located in guard cells, presumably to elicit stomata closure. In the roots, at the end of the first drought cycle, while strong IAA accumulation was observed in the cortex, ABA levels decreased probably due to translocation to the leaves. Rewatering modified the distribution of both IAA and ABA in the needles, causing an accumulation principally in vascular tissue, with residual concentrations in mesophyll, likely favouring the acclimatization of the plants for further drought cycles. Contrarily, in the roots IAA and ABA were located in the exodermis, a natural barrier that regulates the phytohormone translocation to other plant tissues and hormone losses to the soil solution after rewatering. These results confirm that immunolocalization is an efficient tool to understand the translocation of IAA and ABA in plants subjected to different water stress situations, and clarify their role in regulating physiological responses such as stomata closure and epinasty in needles and root development.

The influence of HOPE VI neighborhood revitalization on neighborhood-based physical activity: A mixed-methods approach.

PubMed

Dulin-Keita, Akilah; Clay, Olivio; Whittaker, Shannon; Hannon, Lonnie; Adams, Ingrid K; Rogers, Michelle; Gans, Kim

2015-08-01

This study uses a mixed methods approach to 1) identify surrounding residents' perceived expectations for Housing Opportunities for People Everywhere (HOPE VI) policy on physical activity outcomes and to 2) quantitatively examine the odds of neighborhood-based physical activity pre-/post-HOPE VI in a low socioeconomic status, predominantly African American community in Birmingham, Alabama. To address aim one, we used group concept mapping which is a structured approach for data collection and analyses that produces pictures/maps of ideas. Fifty-eight residents developed statements about potential influences of HOPE VI on neighborhood-based physical activity. In the quantitative study, we examined whether these potential influences increased the odds of neighborhood walking/jogging. We computed block entry logistic regression models with a larger cohort of residents at baseline (n = 184) and six-months (n = 142, 77% retention; n = 120 for all informative variables). We examined perceived neighborhood disorder (perceived neighborhood disorder scale), walkability and aesthetics (Neighborhood Environment Walkability Scale) and HOPE VI-related community safety and safety for physical activity as predictors. During concept mapping, residents generated statements that clustered into three distinct concepts, "Increased Leisure Physical Activity," "Safe Play Areas," and "Generating Health Promoting Resources." The quantitative analyses indicated that changes in neighborhood walkability increased the odds of neighborhood-based physical activity (p = 0.04). When HOPE VI-related safety for physical activity was entered into the model, it was associated with increased odds of physical activity (p = 0.04). Walkability was no longer statistically significant. These results suggest that housing policies that create walkable neighborhoods and that improve perceptions of safety for physical activity may increase neighborhood-based physical activity. However, the longer term impacts of neighborhood-level policies on physical activity require more longitudinal evidence to determine whether increased participation in physical activity is sustained. Copyright © 2015 Elsevier Ltd. All rights reserved.

Crisis DSM Generation To Support Refugee Camp Management

NASA Astrophysics Data System (ADS)

Gstaiger, Veronika; d'Angelo, Pablo; Schneiderhan, Tobais; Krauss, Thomas

2013-12-01

The extraction of high resolution surface information from satellite data has become an important area of research. One of the numerous fields of application is disaster management. Detailed information about the affected terrain is not only needed for analyses during the emergency relief phase, but also for reconstruction and prevention activities. In this paper the authors present the generation of a Digital Surface Model (DSM) based on three very high resolution optical satellite images. The DSM was produced to supplement a flood mapping activity in Jordan and serves as example for the implementation of scientific results during an emergency request. The flood affected the Zaatari refugee camp in Jordan and was mapped by the Center for Satellite Based Crisis Information (ZKI) at the German Aerospace Center (DLR) in January 2013 under emergency mapping conditions.

On testing for spatial correspondence between maps of human brain structure and function.

PubMed

Alexander-Bloch, Aaron F; Shou, Haochang; Liu, Siyuan; Satterthwaite, Theodore D; Glahn, David C; Shinohara, Russell T; Vandekar, Simon N; Raznahan, Armin

2018-06-01

A critical issue in many neuroimaging studies is the comparison between brain maps. Nonetheless, it remains unclear how one should test hypotheses focused on the overlap or spatial correspondence between two or more brain maps. This "correspondence problem" affects, for example, the interpretation of comparisons between task-based patterns of functional activation, resting-state networks or modules, and neuroanatomical landmarks. To date, this problem has been addressed with remarkable variability in terms of methodological approaches and statistical rigor. In this paper, we address the correspondence problem using a spatial permutation framework to generate null models of overlap by applying random rotations to spherical representations of the cortical surface, an approach for which we also provide a theoretical statistical foundation. We use this method to derive clusters of cognitive functions that are correlated in terms of their functional neuroatomical substrates. In addition, using publicly available data, we formally demonstrate the correspondence between maps of task-based functional activity, resting-state fMRI networks and gyral-based anatomical landmarks. We provide open-access code to implement the methods presented for two commonly-used tools for surface based cortical analysis (https://www.github.com/spin-test). This spatial permutation approach constitutes a useful advance over widely-used methods for the comparison of cortical maps, thereby opening new possibilities for the integration of diverse neuroimaging data. Copyright © 2018 Elsevier Inc. All rights reserved.

The Tongue Map, Real or Not?

ERIC Educational Resources Information Center

Marshall, Pamela A.

2013-01-01

Students need practice in proposing hypotheses, developing experiments that will test these hypotheses, and generating data that they will analyze to support or refute them. I describe a guided-inquiry activity based on the "tongue map" concept, appropriate for middle school and high school students.

Application of Satellite SAR Imagery in Mapping the Active Layer of Arctic Permafrost

NASA Technical Reports Server (NTRS)

Li, Shu-Sun; Romanovsky, V.; Lovick, Joe; Wang, Z.; Peterson, Rorik

2003-01-01

A method of mapping the active layer of Arctic permafrost using a combination of conventional synthetic aperture radar (SAR) backscatter and more sophisticated interferometric SAR (INSAR) techniques is proposed. The proposed research is based on the sensitivity of radar backscatter to the freeze and thaw status of the surface soil, and the sensitivity of INSAR techniques to centimeter- to sub-centimeter-level surface differential deformation. The former capability of SAR is investigated for deriving the timing and duration of the thaw period for surface soil of the active layer over permafrost. The latter is investigated for the feasibility of quantitative measurement of frost heaving and thaw settlement of the active layer during the freezing and thawing processes. The resulting knowledge contributes to remote sensing mapping of the active layer dynamics and Arctic land surface hydrology.

Color Shaded-Relief and Surface-Classification Maps of the Fish Creek Area, Harrison Bay Quadrangle, Northern Alaska

USGS Publications Warehouse

Mars, John L.; Garrity, Christopher P.; Houseknecht, David W.; Amoroso, Lee; Meares, Donald C.

2007-01-01

Introduction The northeastern part of the National Petroleum Reserve in Alaska (NPRA) has become an area of active petroleum exploration during the past five years. Recent leasing and exploration drilling in the NPRA requires the U.S. Bureau of Land Management (BLM) to manage and monitor a variety of surface activities that include seismic surveying, exploration drilling, oil-field development drilling, construction of oil-production facilities, and construction of pipelines and access roads. BLM evaluates a variety of permit applications, environmental impact studies, and other documents that require rapid compilation and analysis of data pertaining to surface and subsurface geology, hydrology, and biology. In addition, BLM must monitor these activities and assess their impacts on the natural environment. Timely and accurate completion of these land-management tasks requires elevation, hydrologic, geologic, petroleum-activity, and cadastral data, all integrated in digital formats at a higher resolution than is currently available in nondigital (paper) formats. To support these land-management tasks, a series of maps was generated from remotely sensed data in an area of high petroleum-industry activity (fig. 1). The maps cover an area from approximately latitude 70?00' N. to 70?30' N. and from longitude 151?00' W. to 153?10' W. The area includes the Alpine oil field in the east, the Husky Inigok exploration well (site of a landing strip) in the west, many of the exploration wells drilled in NPRA since 2000, and the route of a proposed pipeline to carry oil from discovery wells in NPRA to the Alpine oil field. This map area is referred to as the 'Fish Creek area' after a creek that flows through the region. The map series includes (1) a color shaded-relief map based on 5-m-resolution data (sheet 1), (2) a surface-classification map based on 30-m-resolution data (sheet 2), and (3) a 5-m-resolution shaded relief-surface classification map that combines the shaded-relief and surface-classification data (sheet 3). Remote sensing datasets that were used to compile the maps include Landsat 7 Enhanced Thematic Mapper+ (ETM+), and interferometric synthetic aperture radar (IFSAR) data. In addition, a 1:250,000-scale geologic map of the Harrison Bay quadrangle, Alaska (Carter and Galloway, 1985, 2005) was used in conjunction with ETM+ and IFSAR data.

Intrinsic optical signal imaging of the blood volume changes is sufficient for mapping the resting state functional connectivity in the rodent cortex

NASA Astrophysics Data System (ADS)

Kura, Sreekanth; Xie, Hongyu; Fu, Buyin; Ayata, Cenk; Boas, David A.; Sakadžić, Sava

2018-06-01

Objective. Resting state functional connectivity (RSFC) allows the study of functional organization in normal and diseased brain by measuring the spontaneous brain activity generated under resting conditions. Intrinsic optical signal imaging (IOSI) based on multiple illumination wavelengths has been used successfully to compute RSFC maps in animal studies. The IOSI setup complexity would be greatly reduced if only a single wavelength can be used to obtain comparable RSFC maps. Approach. We used anesthetized mice and performed various comparisons between the RSFC maps based on single wavelength as well as oxy-, deoxy- and total hemoglobin concentration changes. Main results. The RSFC maps based on IOSI at a single wavelength selected for sensitivity to the blood volume changes are quantitatively comparable to the RSFC maps based on oxy- and total hemoglobin concentration changes obtained by the more complex IOSI setups. Moreover, RSFC maps do not require CCD cameras with very high frame acquisition rates, since our results demonstrate that they can be computed from the data obtained at frame rates as low as 5 Hz. Significance. Our results will have general utility for guiding future RSFC studies based on IOSI and making decisions about the IOSI system designs.

Mapping Sub-Saharan African Agriculture in High-Resolution Satellite Imagery with Computer Vision & Machine Learning

NASA Astrophysics Data System (ADS)

Debats, Stephanie Renee

Smallholder farms dominate in many parts of the world, including Sub-Saharan Africa. These systems are characterized by small, heterogeneous, and often indistinct field patterns, requiring a specialized methodology to map agricultural landcover. In this thesis, we developed a benchmark labeled data set of high-resolution satellite imagery of agricultural fields in South Africa. We presented a new approach to mapping agricultural fields, based on efficient extraction of a vast set of simple, highly correlated, and interdependent features, followed by a random forest classifier. The algorithm achieved similar high performance across agricultural types, including spectrally indistinct smallholder fields, and demonstrated the ability to generalize across large geographic areas. In sensitivity analyses, we determined multi-temporal images provided greater performance gains than the addition of multi-spectral bands. We also demonstrated how active learning can be incorporated in the algorithm to create smaller, more efficient training data sets, which reduced computational resources, minimized the need for humans to hand-label data, and boosted performance. We designed a patch-based uncertainty metric to drive the active learning framework, based on the regular grid of a crowdsourcing platform, and demonstrated how subject matter experts can be replaced with fleets of crowdsourcing workers. Our active learning algorithm achieved similar performance as an algorithm trained with randomly selected data, but with 62% less data samples. This thesis furthers the goal of providing accurate agricultural landcover maps, at a scale that is relevant for the dominant smallholder class. Accurate maps are crucial for monitoring and promoting agricultural production. Furthermore, improved agricultural landcover maps will aid a host of other applications, including landcover change assessments, cadastral surveys to strengthen smallholder land rights, and constraints for crop modeling and famine prediction.

Assignment of functional activations to probabilistic cytoarchitectonic areas revisited.

PubMed

Eickhoff, Simon B; Paus, Tomas; Caspers, Svenja; Grosbras, Marie-Helene; Evans, Alan C; Zilles, Karl; Amunts, Katrin

2007-07-01

Probabilistic cytoarchitectonic maps in standard reference space provide a powerful tool for the analysis of structure-function relationships in the human brain. While these microstructurally defined maps have already been successfully used in the analysis of somatosensory, motor or language functions, several conceptual issues in the analysis of structure-function relationships still demand further clarification. In this paper, we demonstrate the principle approaches for anatomical localisation of functional activations based on probabilistic cytoarchitectonic maps by exemplary analysis of an anterior parietal activation evoked by visual presentation of hand gestures. After consideration of the conceptual basis and implementation of volume or local maxima labelling, we comment on some potential interpretational difficulties, limitations and caveats that could be encountered. Extending and supplementing these methods, we then propose a supplementary approach for quantification of structure-function correspondences based on distribution analysis. This approach relates the cytoarchitectonic probabilities observed at a particular functionally defined location to the areal specific null distribution of probabilities across the whole brain (i.e., the full probability map). Importantly, this method avoids the need for a unique classification of voxels to a single cortical area and may increase the comparability between results obtained for different areas. Moreover, as distribution-based labelling quantifies the "central tendency" of an activation with respect to anatomical areas, it will, in combination with the established methods, allow an advanced characterisation of the anatomical substrates of functional activations. Finally, the advantages and disadvantages of the various methods are discussed, focussing on the question of which approach is most appropriate for a particular situation.

Systems-level identification of PKA-dependent signaling in epithelial cells.

PubMed

Isobe, Kiyoshi; Jung, Hyun Jun; Yang, Chin-Rang; Claxton, J'Neka; Sandoval, Pablo; Burg, Maurice B; Raghuram, Viswanathan; Knepper, Mark A

2017-10-17

G protein stimulatory α-subunit (G αs )-coupled heptahelical receptors regulate cell processes largely through activation of protein kinase A (PKA). To identify signaling processes downstream of PKA, we deleted both PKA catalytic subunits using CRISPR-Cas9, followed by a "multiomic" analysis in mouse kidney epithelial cells expressing the G αs -coupled V2 vasopressin receptor. RNA-seq (sequencing)-based transcriptomics and SILAC (stable isotope labeling of amino acids in cell culture)-based quantitative proteomics revealed a complete loss of expression of the water-channel gene Aqp2 in PKA knockout cells. SILAC-based quantitative phosphoproteomics identified 229 PKA phosphorylation sites. Most of these PKA targets are thus far unannotated in public databases. Surprisingly, 1,915 phosphorylation sites with the motif x-(S/T)-P showed increased phosphooccupancy, pointing to increased activity of one or more MAP kinases in PKA knockout cells. Indeed, phosphorylation changes associated with activation of ERK2 were seen in PKA knockout cells. The ERK2 site is downstream of a direct PKA site in the Rap1GAP, Sipa1l1, that indirectly inhibits Raf1. In addition, a direct PKA site that inhibits the MAP kinase kinase kinase Map3k5 (ASK1) is upstream of JNK1 activation. The datasets were integrated to identify a causal network describing PKA signaling that explains vasopressin-mediated regulation of membrane trafficking and gene transcription. The model predicts that, through PKA activation, vasopressin stimulates AQP2 exocytosis by inhibiting MAP kinase signaling. The model also predicts that, through PKA activation, vasopressin stimulates Aqp2 transcription through induction of nuclear translocation of the acetyltransferase EP300, which increases histone H3K27 acetylation of vasopressin-responsive genes (confirmed by ChIP-seq).

Self-organizing maps based on limit cycle attractors.

PubMed

Huang, Di-Wei; Gentili, Rodolphe J; Reggia, James A

2015-03-01

Recent efforts to develop large-scale brain and neurocognitive architectures have paid relatively little attention to the use of self-organizing maps (SOMs). Part of the reason for this is that most conventional SOMs use a static encoding representation: each input pattern or sequence is effectively represented as a fixed point activation pattern in the map layer, something that is inconsistent with the rhythmic oscillatory activity observed in the brain. Here we develop and study an alternative encoding scheme that instead uses sparsely-coded limit cycles to represent external input patterns/sequences. We establish conditions under which learned limit cycle representations arise reliably and dominate the dynamics in a SOM. These limit cycles tend to be relatively unique for different inputs, robust to perturbations, and fairly insensitive to timing. In spite of the continually changing activity in the map layer when a limit cycle representation is used, map formation continues to occur reliably. In a two-SOM architecture where each SOM represents a different sensory modality, we also show that after learning, limit cycles in one SOM can correctly evoke corresponding limit cycles in the other, and thus there is the potential for multi-SOM systems using limit cycles to work effectively as hetero-associative memories. While the results presented here are only first steps, they establish the viability of SOM models based on limit cycle activity patterns, and suggest that such models merit further study. Copyright © 2014 Elsevier Ltd. All rights reserved.

EnviroAtlas National Layers Master Web Service

EPA Pesticide Factsheets

This EnviroAtlas web service supports research and online mapping activities related to EnviroAtlas (https://www.epa.gov/enviroatlas). This web service includes layers depicting EnviroAtlas national metrics mapped at the 12-digit HUC within the conterminous United States. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

Antiretroviral Therapy Program Expansion in Zambézia Province, Mozambique: Geospatial Mapping of Community-Based and Health Facility Data for Integrated Health Planning

PubMed Central

Moon, Troy D.; Ossemane, Ezequiel B.; Green, Ann F.; Ndatimana, Elisée; José, Eurico; Buehler, Charlotte P.; Wester, C. William; Vermund, Sten H.; Olupona, Omo

2014-01-01

Objective To generate maps reflecting the intersection of community-based Voluntary Counseling and Testing (VCT) delivery points with facility-based HIV program demographic information collected at the district level in three districts (Ile, Maganja da Costa and Chinde) of Zambézia Province, Mozambique; in order to guide planning decisions about antiretroviral therapy (ART) program expansion. Methods Program information was harvested from two separate open source databases maintained for community-based VCT and facility-based HIV care and treatment monitoring from October 2011 to September 2012. Maps were created using ArcGIS 10.1. Travel distance by foot within a 10 km radius is generally considered a tolerable distance in Mozambique for purposes of adherence and retention planning. Results Community-based VCT activities in each of three districts were clustered within geographic proximity to clinics providing ART, within communities with easier transportation access, and/or near the homes of VCT volunteers. Community HIV testing results yielded HIV seropositivity rates in some regions that were incongruent with the Ministry of Health’s estimates for the entire district (2–13% vs. 2% in Ile, 2–54% vs. 11.5% in Maganja da Costa, and 23–43% vs. 14.4% in Chinde). All 3 districts revealed gaps in regional disbursement of community-based VCT activities as well as access to clinics offering ART. Conclusions Use of geospatial mapping in the context of program planning and monitoring allowed for characterizing the location and size of each district’s HIV population. In extremely resource limited and logistically challenging settings, maps are valuable tools for informing evidence-based decisions in planning program expansion, including ART. PMID:25329169

Spatial Patterns of High Aedes aegypti Oviposition Activity in Northwestern Argentina

PubMed Central

Estallo, Elizabet Lilia; Más, Guillermo; Vergara-Cid, Carolina; Lanfri, Mario Alberto; Ludueña-Almeida, Francisco; Scavuzzo, Carlos Marcelo; Introini, María Virginia; Zaidenberg, Mario; Almirón, Walter Ricardo

2013-01-01

Background In Argentina, dengue has affected mainly the Northern provinces, including Salta. The objective of this study was to analyze the spatial patterns of high Aedes aegypti oviposition activity in San Ramón de la Nueva Orán, northwestern Argentina. The location of clusters as hot spot areas should help control programs to identify priority areas and allocate their resources more effectively. Methodology Oviposition activity was detected in Orán City (Salta province) using ovitraps, weekly replaced (October 2005–2007). Spatial autocorrelation was measured with Moran’s Index and depicted through cluster maps to identify hot spots. Total egg numbers were spatially interpolated and a classified map with Ae. aegypti high oviposition activity areas was performed. Potential breeding and resting (PBR) sites were geo-referenced. A logistic regression analysis of interpolated egg numbers and PBR location was performed to generate a predictive mapping of mosquito oviposition activity. Principal Findings Both cluster maps and predictive map were consistent, identifying in central and southern areas of the city high Ae. aegypti oviposition activity. A logistic regression model was successfully developed to predict Ae. aegypti oviposition activity based on distance to PBR sites, with tire dumps having the strongest association with mosquito oviposition activity. A predictive map reflecting probability of oviposition activity was produced. The predictive map delimitated an area of maximum probability of Ae. aegypti oviposition activity in the south of Orán city where tire dumps predominate. The overall fit of the model was acceptable (ROC = 0.77), obtaining 99% of sensitivity and 75.29% of specificity. Conclusions Distance to tire dumps is inversely associated with high mosquito activity, allowing us to identify hot spots. These methodologies are useful for prevention, surveillance, and control of tropical vector borne diseases and might assist National Health Ministry to focus resources more effectively. PMID:23349813

Arabidopsis Duodecuple Mutant of PYL ABA Receptors Reveals PYL Repression of ABA-Independent SnRK2 Activity.

PubMed

Zhao, Yang; Zhang, Zhengjing; Gao, Jinghui; Wang, Pengcheng; Hu, Tao; Wang, Zegang; Hou, Yueh-Ju; Wan, Yizhen; Liu, Wenshan; Xie, Shaojun; Lu, Tianjiao; Xue, Liang; Liu, Yajie; Macho, Alberto P; Tao, W Andy; Bressan, Ray A; Zhu, Jian-Kang

2018-06-12

Abscisic acid (ABA) is an important phytohormone controlling responses to abiotic stresses and is sensed by proteins from the PYR/PYL/RCAR family. To explore the genetic contribution of PYLs toward ABA-dependent and ABA-independent processes, we generated and characterized high-order Arabidopsis mutants with mutations in the PYL family. We obtained a pyl quattuordecuple mutant and found that it was severely impaired in growth and failed to produce seeds. Thus, we carried out a detailed characterization of a pyl duodecuple mutant, pyr1pyl1/2/3/4/5/7/8/9/10/11/12. The duodecuple mutant was extremely insensitive to ABA effects on seed germination, seedling growth, stomatal closure, leaf senescence, and gene expression. The activation of SnRK2 protein kinases by ABA was blocked in the duodecuple mutant, but, unexpectedly, osmotic stress activation of SnRK2s was enhanced. Our results demonstrate an important role of basal ABA signaling in growth, senescence, and abscission and reveal that PYLs antagonize ABA-independent activation of SnRK2s by osmotic stress. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

The endocrine disruptor nonylphenol induces sublethal toxicity in vascular plant development at environmental concentrations: A risk for riparian plants and irrigated crops?

PubMed

Esteban, S; Llamas, P M; García-Cortés, H; Catalá, M

2016-09-01

In recent years, there is a growing concern among the scientific community about the presence of the so-called emergent pollutants in waters of different countries, especially endocrine-disrupting compounds (EDCs) that have the ability to alter the hormonal system. One of the substances found almost ubiquitously and in higher concentrations is the alkylphenol nonylphenol. Albeit this compound is included in priority lists as a probable risk for human health and the environment, little is known about its effects on developing plants. The aim of this work is to assess the acute and sub-chronic toxicity of environmental concentrations of nonylphenol in riparian vascular plant development using spores of the fern Polystichum setiferum and a biomarker-based approach: mitochondrial activity (cell viability), chlorophyll (plant physiology) and DNA content (growth). Mitochondrial activity and DNA content show that nonylphenol induces acute and sub-chronic toxicity at 48 h and after 1 week, respectively. Significant effects are observed in both parameters in fern spores at ng L(-1) but chlorophyll autofluorescence shows little changes. The inhibition of germination by natural allelochemicals has been reported to be related with the active hydroxyl group of phenolic compounds and largely independent of the structural nucleus to which it is attached. Results presented in this study suggest that environmental concentrations of nonylphenol could interfere with higher plant germination development by mimicking natural allelochemicals and/or phytohormones acting as a "phytoendocrine disruptor" likely posing ecophysiological risks. Copyright © 2016 Elsevier Ltd. All rights reserved.

Role of Ongoing, Intrinsic Activity of Neuronal Populations for Quantitative Neuroimaging of Functional Magnetic Resonance Imaging–Based Networks

PubMed Central

Herman, Peter; Sanganahalli, Basavaraju G.; Coman, Daniel; Blumenfeld, Hal; Rothman, Douglas L.

2011-01-01

Abstract A primary objective in neuroscience is to determine how neuronal populations process information within networks. In humans and animal models, functional magnetic resonance imaging (fMRI) is gaining increasing popularity for network mapping. Although neuroimaging with fMRI—conducted with or without tasks—is actively discovering new brain networks, current fMRI data analysis schemes disregard the importance of the total neuronal activity in a region. In task fMRI experiments, the baseline is differenced away to disclose areas of small evoked changes in the blood oxygenation level-dependent (BOLD) signal. In resting-state fMRI experiments, the spotlight is on regions revealed by correlations of tiny fluctuations in the baseline (or spontaneous) BOLD signal. Interpretation of fMRI-based networks is obscured further, because the BOLD signal indirectly reflects neuronal activity, and difference/correlation maps are thresholded. Since the small changes of BOLD signal typically observed in cognitive fMRI experiments represent a minimal fraction of the total energy/activity in a given area, the relevance of fMRI-based networks is uncertain, because the majority of neuronal energy/activity is ignored. Thus, another alternative for quantitative neuroimaging of fMRI-based networks is a perspective in which the activity of a neuronal population is accounted for by the demanded oxidative energy (CMRO2). In this article, we argue that network mapping can be improved by including neuronal energy/activity of both the information about baseline and small differences/fluctuations of BOLD signal. Thus, total energy/activity information can be obtained through use of calibrated fMRI to quantify differences of ΔCMRO2 and through resting-state positron emission tomography/magnetic resonance spectroscopy measurements for average CMRO2. PMID:22433047

Toward Building a New Seismic Hazard Model for Mainland China

NASA Astrophysics Data System (ADS)

Rong, Y.; Xu, X.; Chen, G.; Cheng, J.; Magistrale, H.; Shen, Z.

2015-12-01

At present, the only publicly available seismic hazard model for mainland China was generated by Global Seismic Hazard Assessment Program in 1999. We are building a new seismic hazard model by integrating historical earthquake catalogs, geological faults, geodetic GPS data, and geology maps. To build the model, we construct an Mw-based homogeneous historical earthquake catalog spanning from 780 B.C. to present, create fault models from active fault data using the methodology recommended by Global Earthquake Model (GEM), and derive a strain rate map based on the most complete GPS measurements and a new strain derivation algorithm. We divide China and the surrounding regions into about 20 large seismic source zones based on seismotectonics. For each zone, we use the tapered Gutenberg-Richter (TGR) relationship to model the seismicity rates. We estimate the TGR a- and b-values from the historical earthquake data, and constrain corner magnitude using the seismic moment rate derived from the strain rate. From the TGR distributions, 10,000 to 100,000 years of synthetic earthquakes are simulated. Then, we distribute small and medium earthquakes according to locations and magnitudes of historical earthquakes. Some large earthquakes are distributed on active faults based on characteristics of the faults, including slip rate, fault length and width, and paleoseismic data, and the rest to the background based on the distributions of historical earthquakes and strain rate. We evaluate available ground motion prediction equations (GMPE) by comparison to observed ground motions. To apply appropriate GMPEs, we divide the region into active and stable tectonics. The seismic hazard will be calculated using the OpenQuake software developed by GEM. To account for site amplifications, we construct a site condition map based on geology maps. The resulting new seismic hazard map can be used for seismic risk analysis and management, and business and land-use planning.

Mapping as a visual health communication tool: promises and dilemmas.

PubMed

Parrott, Roxanne; Hopfer, Suellen; Ghetian, Christie; Lengerich, Eugene

2007-01-01

In the era of evidence-based public health promotion and planning, the use of maps as a form of evidence to communicate about the multiple determinants of cancer is on the rise. Geographic information systems and mapping technologies make future proliferation of this strategy likely. Yet disease maps as a communication form remain largely unexamined. This content analysis considers the presence of multivariate information, credibility cues, and the communication function of publicly accessible maps for cancer control activities. Thirty-six state comprehensive cancer control plans were publicly available in July 2005 and were reviewed for the presence of maps. Fourteen of the 36 state cancer plans (39%) contained map images (N = 59 static maps). A continuum of map inter activity was observed, with 10 states having interactive mapping tools available to query and map cancer information. Four states had both cancer plans with map images and interactive mapping tools available to the public on their Web sites. Of the 14 state cancer plans that depicted map images, two displayed multivariate data in a single map. Nine of the 10 states with interactive mapping capability offered the option to display multivariate health risk messages. The most frequent content category mapped was cancer incidence and mortality, with stage at diagnosis infrequently available. The most frequent communication function served by the maps reviewed was redundancy, as maps repeated information contained in textual forms. The social and ethical implications for communicating about cancer through the use of visual geographic representations are discussed.

Hepatic fat quantification using the two-point Dixon method and fat color maps based on non-alcoholic fatty liver disease activity score.

PubMed

Hayashi, Tatsuya; Saitoh, Satoshi; Takahashi, Junji; Tsuji, Yoshinori; Ikeda, Kenji; Kobayashi, Masahiro; Kawamura, Yusuke; Fujii, Takeshi; Inoue, Masafumi; Miyati, Tosiaki; Kumada, Hiromitsu

2017-04-01

The two-point Dixon method for magnetic resonance imaging (MRI) is commonly used to non-invasively measure fat deposition in the liver. The aim of the present study was to assess the usefulness of MRI-fat fraction (MRI-FF) using the two-point Dixon method based on the non-alcoholic fatty liver disease activity score. This retrospective study included 106 patients who underwent liver MRI and MR spectroscopy, and 201 patients who underwent liver MRI and histological assessment. The relationship between MRI-FF and MR spectroscopy-fat fraction was used to estimate the corrected MRI-FF for hepatic multi-peaks of fat. Then, a color FF map was generated with the corrected MRI-FF based on the non-alcoholic fatty liver disease activity score. We defined FF variability as the standard deviation of FF in regions of interest. Uniformity of hepatic fat was visually graded on a three-point scale using both gray-scale and color FF maps. Confounding effects of histology (iron, inflammation and fibrosis) on corrected MRI-FF were assessed by multiple linear regression. The linear correlations between MRI-FF and MR spectroscopy-fat fraction, and between corrected MRI-FF and histological steatosis were strong (R 2  = 0.90 and R 2  = 0.88, respectively). Liver fat variability significantly increased with visual fat uniformity grade using both of the maps (ρ = 0.67-0.69, both P < 0.001). Hepatic iron, inflammation and fibrosis had no significant confounding effects on the corrected MRI-FF (all P > 0.05). The two-point Dixon method and the gray-scale or color FF maps based on the non-alcoholic fatty liver disease activity score were useful for fat quantification in the liver of patients without severe iron deposition. © 2016 The Japan Society of Hepatology.

Herbivory Rapidly Activates MAPK Signaling in Attacked and Unattacked Leaf Regions but Not between Leaves of Nicotiana attenuata[W

PubMed Central

Wu, Jianqiang; Hettenhausen, Christian; Meldau, Stefan; Baldwin, Ian T.

2007-01-01

Mitogen-activated protein kinase (MAPK) signaling plays a central role in transducing extracellular stimuli into intracellular responses, but its role in mediating plant responses to herbivore attack remains largely unexplored. When Manduca sexta larvae attack their host plant, Nicotiana attenuata, the plant's wound response is reconfigured at transcriptional, phytohormonal, and defensive levels due to the introduction of oral secretions (OS) into wounds during feeding. We show that OS dramatically amplify wound-induced MAPK activity and that fatty acid–amino acid conjugates in M. sexta OS are the elicitors. Virus-induced gene silencing of salicylic acid–induced protein kinase (SIPK) and wound-induced protein kinase revealed their importance in mediating wound and OS-elicited hormonal responses and transcriptional regulation of defense-related genes. We found that after applying OS to wounds created in one portion of a leaf, SIPK is activated in both wounded and specific unwounded regions of the leaf but not in phylotactically connected adjacent leaves. We propose that M. sexta attack elicits a mobile signal that travels to nonwounded regions of the attacked leaf where it activates MAPK signaling and, thus, downstream responses; subsequently, a different signal is transported by the vascular system to systemic leaves to initiate defense responses without activating MAPKs in systemic leaves. PMID:17400894

Molecular cloning and expression analysis of jasmonic acid dependent but salicylic acid independent LeWRKY1.

PubMed

Lu, M; Wang, L F; Du, X H; Yu, Y K; Pan, J B; Nan, Z J; Han, J; Wang, W X; Zhang, Q Z; Sun, Q P

2015-11-30

Various plant genes can be activated or inhibited by phytohormones under conditions of biotic and abiotic stress, especially in response to jasmonic acid (JA) and salicylic acid (SA). Interactions between JA and SA may be synergistic or antagonistic, depending on the stress condition. In this study, we cloned a full-length cDNA (LeWRKY1, GenBank accession No. FJ654265) from Lycopersicon esculentum by rapid amplification of cDNA ends. Sequence analysis showed that this gene is a group II WRKY transcription factor. Analysis of LeWRKY1 mRNA expression in various tissues by qRT-PCR showed that the highest and lowest expression occurred in the leaves and stems, respectively. In addition, LeWRKY1 expression was induced by JA and Botrytis cinerea Pers., but not by SA.

Deciphering the cryptic genome: Genome-wide analyses of the rice pathogen Fusarium fujikuroi reveal complex regulation of secondary metabolism and novel metabolites

USDA-ARS?s Scientific Manuscript database

The fungus Fusarium fujikuroi is agriculturally important because it produces the phytohormones gibberellic acids (GAs) and causes bakanae (“foolish seedling”) disease of rice. The fungus also produces multiple other secondary metabolites, including pigments and mycotoxins. Here, we present a high-q...

Profiling of Altered Metabolomic States in Nicotiana tabacum Cells Induced by Priming Agents

PubMed Central

Mhlongo, Msizi I.; Steenkamp, Paul A.; Piater, Lizelle A.; Madala, Ntakadzeni E.; Dubery, Ian A.

2016-01-01

Metabolomics has developed into a valuable tool for advancing our understanding of plant metabolism. Plant innate immune defenses can be activated and enhanced so that, subsequent to being pre-sensitized, plants are able to launch a stronger and faster defense response upon exposure to pathogenic microorganisms, a phenomenon known as priming. Here, three contrasting chemical activators, namely acibenzolar-S-methyl, azelaic acid and riboflavin, were used to induce a primed state in Nicotiana tabacum cells. Identified biomarkers were then compared to responses induced by three phytohormones—abscisic acid, methyljasmonate, and salicylic acid. Altered metabolomes were studied using a metabolite fingerprinting approach based on liquid chromatography and mass spectrometry. Multivariate data models indicated that these inducers cause time-dependent metabolic perturbations in the cultured cells and revealed biomarkers of which the levels are affected by these agents. A total of 34 metabolites were annotated from the mass spectral data and online databases. Venn diagrams were used to identify common biomarkers as well as those unique to a specific agent. Results implicate 20 cinnamic acid derivatives conjugated to (i) quinic acid (chlorogenic acids), (ii) tyramine, (iii) polyamines, or (iv) glucose as discriminatory biomarkers of priming in tobacco cells. Functional roles for most of these metabolites in plant defense responses could thus be proposed. Metabolites induced by the activators belong to the early phenylpropanoid pathway, which indicates that different stimuli can activate similar pathways but with different metabolite fingerprints. Possible linkages to phytohormone-dependent pathways at a metabolomic level were indicated in the case of cells treated with salicylic acid and methyljasmonate. The results contribute to a better understanding of the priming phenomenon and advance our knowledge of cinnamic acid derivatives as versatile defense metabolites. PMID:27803705

Astrobiology Road Mapping (AstRoMap) - A project within FP7 of the European Commission: First results

NASA Astrophysics Data System (ADS)

Gomez-Gomez, Felipe; Capria, Maria Teresa; Palomba, Ernesto; Walter, Nicolas; Rettberg, Petra; Muller, Christian; Horneck, Gerda

AstRoMap (Astrobiology and Planetary Exploration Road Mapping) is a funded project formulated in the 5th Call of the European Commission FP7 framework. The main objectives of the AstRoMap are: 1. Identify the main astrobiology issues to be addressed by Europe in the next decades in relation with space exploration 2. Identify potential mission concepts that would allow addressing these issues 3. Identify the technology developments required to enable these missions 4. Provide a prioritized roadmap integrating science and technology activities as well as ground-based approach 5. Map scientific knowledge related to astrobiology in Europe To reach those objectives, AstRoMap is executed within the following steps: 1. Community consultation. In order to map the European astrobiology landscape and to provide a collaborative networking platform for this community, the AstRoMap project hosts a database of scientists (European and beyond) interested in astrobiology and planetary exploration (see: http://www.astromap.eu/database.html). It reflects the demography and the research and teaching activities of the astrobiology community, as well as their professional profiles and involvement in astrobiology projects. Considering future aspects of astrobiology in Europe, the need for more astrobiology-dedicated funding programmes at the EU level, especially for cross-disciplinary groups, was stressed. This might eventually lead to the creation of a European laboratory of Astrobiology, or even of a European Astrobiology Institute. 2. Workshops organisation. On the basis of the feedbacks from the community consultation, the potential participants and interesting topics are being identified to take part in the following workshops: 1-. Origin of organic compounds, steps to life; 2. Physico-chemical boundary conditions for habitability 3. Biosignatures as facilitating life detection 4. Origin of the Solar system 3. Astrobiology road-mapping. Based on the results and major conclusions elaborated during the workshops, an astrobiology roadmap will be constructed tailored to the European needs and competences. 4. Education and public outreach. Parallel to the workshop and consultation activities, AstRoMap will provide a comprehensive education and outreach programme and disseminate the progress of AstRoMap through its web site (http://www.astromap.eu).

NeuroMap: A Spline-Based Interactive Open-Source Software for Spatiotemporal Mapping of 2D and 3D MEA Data

PubMed Central

Abdoun, Oussama; Joucla, Sébastien; Mazzocco, Claire; Yvert, Blaise

2010-01-01

A major characteristic of neural networks is the complexity of their organization at various spatial scales, from microscopic local circuits to macroscopic brain-scale areas. Understanding how neural information is processed thus entails the ability to study them at multiple scales simultaneously. This is made possible using microelectrodes array (MEA) technology. Indeed, high-density MEAs provide large-scale coverage (several square millimeters) of whole neural structures combined with microscopic resolution (about 50 μm) of unit activity. Yet, current options for spatiotemporal representation of MEA-collected data remain limited. Here we present NeuroMap, a new interactive Matlab-based software for spatiotemporal mapping of MEA data. NeuroMap uses thin plate spline interpolation, which provides several assets with respect to conventional mapping methods used currently. First, any MEA design can be considered, including 2D or 3D, regular or irregular, arrangements of electrodes. Second, spline interpolation allows the estimation of activity across the tissue with local extrema not necessarily at recording sites. Finally, this interpolation approach provides a straightforward analytical estimation of the spatial Laplacian for better current sources localization. In this software, coregistration of 2D MEA data on the anatomy of the neural tissue is made possible by fine matching of anatomical data with electrode positions using rigid-deformation-based correction of anatomical pictures. Overall, NeuroMap provides substantial material for detailed spatiotemporal analysis of MEA data. The package is distributed under GNU General Public License and available at http://sites.google.com/site/neuromapsoftware. PMID:21344013

NeuroMap: A Spline-Based Interactive Open-Source Software for Spatiotemporal Mapping of 2D and 3D MEA Data.

PubMed

Abdoun, Oussama; Joucla, Sébastien; Mazzocco, Claire; Yvert, Blaise

2011-01-01

A major characteristic of neural networks is the complexity of their organization at various spatial scales, from microscopic local circuits to macroscopic brain-scale areas. Understanding how neural information is processed thus entails the ability to study them at multiple scales simultaneously. This is made possible using microelectrodes array (MEA) technology. Indeed, high-density MEAs provide large-scale coverage (several square millimeters) of whole neural structures combined with microscopic resolution (about 50 μm) of unit activity. Yet, current options for spatiotemporal representation of MEA-collected data remain limited. Here we present NeuroMap, a new interactive Matlab-based software for spatiotemporal mapping of MEA data. NeuroMap uses thin plate spline interpolation, which provides several assets with respect to conventional mapping methods used currently. First, any MEA design can be considered, including 2D or 3D, regular or irregular, arrangements of electrodes. Second, spline interpolation allows the estimation of activity across the tissue with local extrema not necessarily at recording sites. Finally, this interpolation approach provides a straightforward analytical estimation of the spatial Laplacian for better current sources localization. In this software, coregistration of 2D MEA data on the anatomy of the neural tissue is made possible by fine matching of anatomical data with electrode positions using rigid-deformation-based correction of anatomical pictures. Overall, NeuroMap provides substantial material for detailed spatiotemporal analysis of MEA data. The package is distributed under GNU General Public License and available at http://sites.google.com/site/neuromapsoftware.

Profiling Bioactivity of the ToxCast Chemical Library Using BioMAP Primary Human Cell Systems

EPA Science Inventory

The complexity of human biology has made prediction of health effects as a consequence of exposure to environmental chemicals especially challenging. Complex cell systems, such as the Biologically Multiplexed Activity Profiling (BioMAP) primary, human, cell-based disease models, ...

Fire blight disease reactome: RNA-seq transcriptional profile of apple host plant defense responses to Erwinia amylovora pathogen infection.

PubMed

Kamber, Tim; Buchmann, Jan P; Pothier, Joël F; Smits, Theo H M; Wicker, Thomas; Duffy, Brion

2016-02-17

The molecular basis of resistance and susceptibility of host plants to fire blight, a major disease threat to pome fruit production globally, is largely unknown. RNA-sequencing data from challenged and mock-inoculated flowers were analyzed to assess the susceptible response of apple to the fire blight pathogen Erwinia amylovora. In presence of the pathogen 1,080 transcripts were differentially expressed at 48 h post inoculation. These included putative disease resistance, stress, pathogen related, general metabolic, and phytohormone related genes. Reads, mapped to regions on the apple genome where no genes were assigned, were used to identify potential novel genes and open reading frames. To identify transcripts specifically expressed in response to E. amylovora, RT-PCRs were conducted and compared to the expression patterns of the fire blight biocontrol agent Pantoea vagans strain C9-1, another apple pathogen Pseudomonas syringae pv. papulans, and mock inoculated apple flowers. This led to the identification of a peroxidase superfamily gene that was lower expressed in response to E. amylovora suggesting a potential role in the susceptibility response. Overall, this study provides the first transcriptional profile by RNA-seq of the host plant during fire blight disease and insights into the response of susceptible apple plants to E. amylovora.

Fire blight disease reactome: RNA-seq transcriptional profile of apple host plant defense responses to Erwinia amylovora pathogen infection

PubMed Central

Kamber, Tim; Buchmann, Jan P.; Pothier, Joël F.; Smits, Theo H. M.; Wicker, Thomas; Duffy, Brion

2016-01-01

The molecular basis of resistance and susceptibility of host plants to fire blight, a major disease threat to pome fruit production globally, is largely unknown. RNA-sequencing data from challenged and mock-inoculated flowers were analyzed to assess the susceptible response of apple to the fire blight pathogen Erwinia amylovora. In presence of the pathogen 1,080 transcripts were differentially expressed at 48 h post inoculation. These included putative disease resistance, stress, pathogen related, general metabolic, and phytohormone related genes. Reads, mapped to regions on the apple genome where no genes were assigned, were used to identify potential novel genes and open reading frames. To identify transcripts specifically expressed in response to E. amylovora, RT-PCRs were conducted and compared to the expression patterns of the fire blight biocontrol agent Pantoea vagans strain C9-1, another apple pathogen Pseudomonas syringae pv. papulans, and mock inoculated apple flowers. This led to the identification of a peroxidase superfamily gene that was lower expressed in response to E. amylovora suggesting a potential role in the susceptibility response. Overall, this study provides the first transcriptional profile by RNA-seq of the host plant during fire blight disease and insights into the response of susceptible apple plants to E. amylovora. PMID:26883568

A diagnostic algorithm to optimize data collection and interpretation of Ripple Maps in atrial tachycardias.

PubMed

Koa-Wing, Michael; Nakagawa, Hiroshi; Luther, Vishal; Jamil-Copley, Shahnaz; Linton, Nick; Sandler, Belinda; Qureshi, Norman; Peters, Nicholas S; Davies, D Wyn; Francis, Darrel P; Jackman, Warren; Kanagaratnam, Prapa

2015-11-15

Ripple Mapping (RM) is designed to overcome the limitations of existing isochronal 3D mapping systems by representing the intracardiac electrogram as a dynamic bar on a surface bipolar voltage map that changes in height according to the electrogram voltage-time relationship, relative to a fiduciary point. We tested the hypothesis that standard approaches to atrial tachycardia CARTO™ activation maps were inadequate for RM creation and interpretation. From the results, we aimed to develop an algorithm to optimize RMs for future prospective testing on a clinical RM platform. CARTO-XP™ activation maps from atrial tachycardia ablations were reviewed by two blinded assessors on an off-line RM workstation. Ripple Maps were graded according to a diagnostic confidence scale (Grade I - high confidence with clear pattern of activation through to Grade IV - non-diagnostic). The RM-based diagnoses were corroborated against the clinical diagnoses. 43 RMs from 14 patients were classified as Grade I (5 [11.5%]); Grade II (17 [39.5%]); Grade III (9 [21%]) and Grade IV (12 [28%]). Causes of low gradings/errors included the following: insufficient chamber point density; window-of-interest<100% of cycle length (CL); <95% tachycardia CL mapped; variability of CL and/or unstable fiducial reference marker; and suboptimal bar height and scar settings. A data collection and map interpretation algorithm has been developed to optimize Ripple Maps in atrial tachycardias. This algorithm requires prospective testing on a real-time clinical platform. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Participatory three dimensional mapping for the preparation of landslide disaster risk reduction program

NASA Astrophysics Data System (ADS)

Kusratmoko, Eko; Wibowo, Adi; Cholid, Sofyan; Pin, Tjiong Giok

2017-07-01

This paper presents the results of applications of participatory three dimensional mapping (P3DM) method for fqcilitating the people of Cibanteng' village to compile a landslide disaster risk reduction program. Physical factors, as high rainfall, topography, geology and land use, and coupled with the condition of demographic and social-economic factors, make up the Cibanteng region highly susceptible to landslides. During the years 2013-2014 has happened 2 times landslides which caused economic losses, as a result of damage to homes and farmland. Participatory mapping is one part of the activities of community-based disaster risk reduction (CBDRR)), because of the involvement of local communities is a prerequisite for sustainable disaster risk reduction. In this activity, participatory mapping method are done in two ways, namely participatory two-dimensional mapping (P2DM) with a focus on mapping of disaster areas and participatory three-dimensional mapping (P3DM) with a focus on the entire territory of the village. Based on the results P3DM, the ability of the communities in understanding the village environment spatially well-tested and honed, so as to facilitate the preparation of the CBDRR programs. Furthermore, the P3DM method can be applied to another disaster areas, due to it becomes a medium of effective dialogue between all levels of involved communities.

The NASA John C. Stennis Environmental Geographic Information System

NASA Technical Reports Server (NTRS)

Cohan, Tyrus

2002-01-01

Contents include the following: 1. Introduction: Background information. Initial applications of the SSC EGIS. Ongoing projects. 2.Scope of SSC EGIS. 3. Data layers. 4. Onsite operations. 5. Landcover classifications. 6. Current activities. 7. GIS/Key. 8. Infrastructure base map - development. 9. Infrastructure base map - application. 10. Incorrected layer. 11. Corrected layer. 12. Emergency environmental response tool. 13. Future directions. 14. Bridging the gaps. 15. Environmental geographical information system.

Language Mapping with Navigated Repetitive TMS: Proof of Technique and Validation

PubMed Central

Tarapore, Phiroz E.; Findlay, Anne M.; Honma, Susanne M.; Mizuiri, Danielle; Houde, John F.; Berger, Mitchel S.; Nagarajan, Srikantan S.

2013-01-01

Objective Lesion-based mapping of speech pathways has been possible only during invasive neurosurgical procedures using direct cortical stimulation (DCS). However, navigated transcranial magnetic stimulation (nTMS) may allow for lesion-based interrogation of language pathways noninvasively. Although not lesion-based, magnetoencephalographic imaging (MEGI) is another noninvasive modality for language mapping. In this study, we compare the accuracy of nTMS and MEGI with DCS. Methods Subjects with lesions around cortical language areas underwent preoperative nTMS and MEGI for language mapping. nTMS maps were generated using a repetitive TMS protocol to deliver trains of stimulations during a picture naming task. MEGI activation maps were derived from adaptive spatial filtering of beta-band power decreases prior to overt speech during picture naming and verb generation tasks. The subjects subsequently underwent awake language mapping via intraoperative DCS. The language maps obtained from each of the 3 modalities were recorded and compared. Results nTMS and MEGI were performed on 12 subjects. nTMS yielded 21 positive language disruption sites (11 speech arrest, 5 anomia, and 5 other) while DCS yielded 10 positive sites (2 speech arrest, 5 anomia, and 3 other). MEGI isolated 32 sites of peak activation with language tasks. Positive language sites were most commonly found in the pars opercularis for all three modalities. In 9 instances the positive DCS site corresponded to a positive nTMS site, while in 1 instance it did not. In 4 instances, a positive nTMS site corresponded to a negative DCS site, while 169 instances of negative nTMS and DCS were recorded. The sensitivity of nTMS was therefore 90%, specificity was 98%, the positive predictive value was 69% and the negative predictive value was 99% as compared with intraoperative DCS. MEGI language sites for verb generation and object naming correlated with nTMS sites in 5 subjects, and with DCS sites in 2 subjects. Conclusion Maps of language function generated with nTMS correlate well with those generated by DCS. Negative nTMS mapping also correlates with negative DCS mapping. In our study, MEGI lacks the same level of correlation with intraoperative mapping; nevertheless it provides useful adjunct information in some cases. nTMS may offer a lesion-based method for noninvasively interrogating language pathways and be valuable in managing patients with peri-eloquent lesions. PMID:23702420

Mapping conduction velocity of early embryonic hearts with a robust fitting algorithm

PubMed Central

Gu, Shi; Wang, Yves T; Ma, Pei; Werdich, Andreas A; Rollins, Andrew M; Jenkins, Michael W

2015-01-01

Cardiac conduction maturation is an important and integral component of heart development. Optical mapping with voltage-sensitive dyes allows sensitive measurements of electrophysiological signals over the entire heart. However, accurate measurements of conduction velocity during early cardiac development is typically hindered by low signal-to-noise ratio (SNR) measurements of action potentials. Here, we present a novel image processing approach based on least squares optimizations, which enables high-resolution, low-noise conduction velocity mapping of smaller tubular hearts. First, the action potential trace measured at each pixel is fit to a curve consisting of two cumulative normal distribution functions. Then, the activation time at each pixel is determined based on the fit, and the spatial gradient of activation time is determined with a two-dimensional (2D) linear fit over a square-shaped window. The size of the window is adaptively enlarged until the gradients can be determined within a preset precision. Finally, the conduction velocity is calculated based on the activation time gradient, and further corrected for three-dimensional (3D) geometry that can be obtained by optical coherence tomography (OCT). We validated the approach using published activation potential traces based on computer simulations. We further validated the method by adding artificially generated noise to the signal to simulate various SNR conditions using a curved simulated image (digital phantom) that resembles a tubular heart. This method proved to be robust, even at very low SNR conditions (SNR = 2-5). We also established an empirical equation to estimate the maximum conduction velocity that can be accurately measured under different conditions (e.g. sampling rate, SNR, and pixel size). Finally, we demonstrated high-resolution conduction velocity maps of the quail embryonic heart at a looping stage of development. PMID:26114034

Documentation of the status of international geothermal power plants and a list by country of selected geothermally active governmental and private sector entities

NASA Astrophysics Data System (ADS)

1992-10-01

This report includes the printouts from the International Geothermal Power Plant Data Base and the Geothermally Active Entity Data Base. Also included are the explanation of the abbreviations used in the power plant data base, maps of geothermal installations by country, and data base questionnaires and mailing lists.

QTL mapping for benzoxazinoid content, preharvest sprouting, α-amylase activity, and leaf rust resistance in rye (Secale cereale L.)

PubMed Central

Masojć, Piotr; Krajewski, Paweł; Stochmal, Anna; Kowalczyk, Mariusz; Angelov, Mihail; Ivanova, Valentina; Schollenberger, Małgorzata; Wakuliński, Wojciech; Banaszak, Zofia; Banaszak, Katarzyna; Rakoczy-Trojanowska, Monika

2017-01-01

Mapping population of recombinant inbred lines (RILs) representing 541 × Ot1-3 cross exhibited wide variations of benzoxazinoid (BX) content in leaves and roots, brown rust resistance, α-amylase activity in the grain, and resistance to preharvest sprouting. QTL mapping of major BX species using a DArT-based map revealed a complex genetic architecture underlying the production of these main secondary metabolites engaged in stress and allelopathy responses. The synthesis of BX in leaves and roots was found to be regulated by different QTL. The QTL for the BX content, rust resistance, α-amylase activity, and preharvest sprouting partially overlapped; this points to their common genetic regulation by a definite subset of genes. Only one QTL for BX located on chromosome 7R coincided with the loci of the ScBx genes, which were mapped as two clusters on chromosomes 5RS (Bx3-Bx5) and 7R (Bx1-Bx2). The QTL common for several BX species, rust resistance, preharvest sprouting, and α-amylase activity are interesting objects for further exploration aimed at developing common markers for these important agronomic traits. PMID:29267335

Dominant Groups of Potentially Active Bacteria Shared by Barley Seeds become Less Abundant in Root Associated Microbiome

PubMed Central

Yang, Luhua; Danzberger, Jasmin; Schöler, Anne; Schröder, Peter; Schloter, Michael; Radl, Viviane

2017-01-01

Endophytes are microorganisms colonizing plant internal tissues. They are ubiquitously associated with plants and play an important role in plant growth and health. In this work, we grew five modern cultivars of barley in axenic systems using sterile sand mixture as well as in greenhouse with natural soil. We characterized the potentially active microbial communities associated with seeds and roots using rRNA based amplicon sequencing. The seeds of the different cultivars share a great part of their microbiome, as we observed a predominance of a few bacterial OTUs assigned to Phyllobacterium, Paenibacillus, and Trabusiella. Seed endophytes, particularly members of the Enterobacteriacea and Paenibacillaceae, were important members of root endophytes in axenic systems, where there were no external microbes. However, when plants were grown in soil, seed endophytes became less abundant in root associated microbiome. We observed a clear enrichment of Actinobacteriacea and Rhizobiaceae, indicating a strong influence of the soil bacterial communities on the composition of the root microbiome. Two OTUs assigned to Phyllobacteriaceae were found in all seeds and root samples growing in soil, indicating a relationship between seed-borne and root associated microbiome in barley. Even though the role of endophytic bacteria remains to be clarified, it is known that many members of the genera detected in our study produce phytohormones, shape seedling exudate profile and may play an important role in germination and establishment of the seedlings. PMID:28663753

Dominant Groups of Potentially Active Bacteria Shared by Barley Seeds become Less Abundant in Root Associated Microbiome.

PubMed

Yang, Luhua; Danzberger, Jasmin; Schöler, Anne; Schröder, Peter; Schloter, Michael; Radl, Viviane

2017-01-01

Endophytes are microorganisms colonizing plant internal tissues. They are ubiquitously associated with plants and play an important role in plant growth and health. In this work, we grew five modern cultivars of barley in axenic systems using sterile sand mixture as well as in greenhouse with natural soil. We characterized the potentially active microbial communities associated with seeds and roots using rRNA based amplicon sequencing. The seeds of the different cultivars share a great part of their microbiome, as we observed a predominance of a few bacterial OTUs assigned to Phyllobacterium , Paenibacillus , and Trabusiella . Seed endophytes, particularly members of the Enterobacteriacea and Paenibacillaceae, were important members of root endophytes in axenic systems, where there were no external microbes. However, when plants were grown in soil, seed endophytes became less abundant in root associated microbiome. We observed a clear enrichment of Actinobacteriacea and Rhizobiaceae, indicating a strong influence of the soil bacterial communities on the composition of the root microbiome. Two OTUs assigned to Phyllobacteriaceae were found in all seeds and root samples growing in soil, indicating a relationship between seed-borne and root associated microbiome in barley. Even though the role of endophytic bacteria remains to be clarified, it is known that many members of the genera detected in our study produce phytohormones, shape seedling exudate profile and may play an important role in germination and establishment of the seedlings.

Salicylic acid signaling inhibits apoplastic reactive oxygen species signaling

PubMed Central

2014-01-01

Background Reactive oxygen species (ROS) are used by plants as signaling molecules during stress and development. Given the amount of possible challenges a plant face from their environment, plants need to activate and prioritize between potentially conflicting defense signaling pathways. Until recently, most studies on signal interactions have focused on phytohormone interaction, such as the antagonistic relationship between salicylic acid (SA)-jasmonic acid and cytokinin-auxin. Results In this study, we report an antagonistic interaction between SA signaling and apoplastic ROS signaling. Treatment with ozone (O3) leads to a ROS burst in the apoplast and induces extensive changes in gene expression and elevation of defense hormones. However, Arabidopsis thaliana dnd1 (defense no death1) exhibited an attenuated response to O3. In addition, the dnd1 mutant displayed constitutive expression of defense genes and spontaneous cell death. To determine the exact process which blocks the apoplastic ROS signaling, double and triple mutants involved in various signaling pathway were generated in dnd1 background. Simultaneous elimination of SA-dependent and SA-independent signaling components from dnd1 restored its responsiveness to O3. Conversely, pre-treatment of plants with SA or using mutants that constitutively activate SA signaling led to an attenuation of changes in gene expression elicited by O3. Conclusions Based upon these findings, we conclude that plants are able to prioritize the response between ROS and SA via an antagonistic action of SA and SA signaling on apoplastic ROS signaling. PMID:24898702

Salicylic acid signaling inhibits apoplastic reactive oxygen species signaling.

PubMed

Xu, Enjun; Brosché, Mikael

2014-06-04

Reactive oxygen species (ROS) are used by plants as signaling molecules during stress and development. Given the amount of possible challenges a plant face from their environment, plants need to activate and prioritize between potentially conflicting defense signaling pathways. Until recently, most studies on signal interactions have focused on phytohormone interaction, such as the antagonistic relationship between salicylic acid (SA)-jasmonic acid and cytokinin-auxin. In this study, we report an antagonistic interaction between SA signaling and apoplastic ROS signaling. Treatment with ozone (O3) leads to a ROS burst in the apoplast and induces extensive changes in gene expression and elevation of defense hormones. However, Arabidopsis thaliana dnd1 (defense no death1) exhibited an attenuated response to O3. In addition, the dnd1 mutant displayed constitutive expression of defense genes and spontaneous cell death. To determine the exact process which blocks the apoplastic ROS signaling, double and triple mutants involved in various signaling pathway were generated in dnd1 background. Simultaneous elimination of SA-dependent and SA-independent signaling components from dnd1 restored its responsiveness to O3. Conversely, pre-treatment of plants with SA or using mutants that constitutively activate SA signaling led to an attenuation of changes in gene expression elicited by O3. Based upon these findings, we conclude that plants are able to prioritize the response between ROS and SA via an antagonistic action of SA and SA signaling on apoplastic ROS signaling.

Stream-sediment and panned-concentrate geochemical maps of the Buffalo Peaks Wilderness Study Area, Lake, Park, and Chaffee counties, Colorado

USGS Publications Warehouse

Nowlan, G.A.; Gerstel, W.J.

1985-01-01

The study area is bounded by several areas of known mineralization (Hedl und and others, 1983). Vein and bedding replacement deposits of silver, zinc, and lead were mined from 1890 until about 1918 in the vicinity of Weston Pass (map A), on the northeastern border of the study area. Gold and silver were mined from about 1860 until about 1880 from veins in the Granite area (map A), on the northwestern border of the study area; minor prospecting activity continues today. From 1935 to 1937, veins of gold, silver, and base metals were mined in the vicinity of Fourmile Creek, on the southwestern border of the study area (map A). Recently, active uranium prospecting has been taking place in the vicinity of the Middle Fork of Salt Creek, on the southeastern border of the study area (map A).

Three-dimensional dominant frequency mapping using autoregressive spectral analysis of atrial electrograms of patients in persistent atrial fibrillation.

PubMed

Salinet, João L; Masca, Nicholas; Stafford, Peter J; Ng, G André; Schlindwein, Fernando S

2016-03-08

Areas with high frequency activity within the atrium are thought to be 'drivers' of the rhythm in patients with atrial fibrillation (AF) and ablation of these areas seems to be an effective therapy in eliminating DF gradient and restoring sinus rhythm. Clinical groups have applied the traditional FFT-based approach to generate the three-dimensional dominant frequency (3D DF) maps during electrophysiology (EP) procedures but literature is restricted on using alternative spectral estimation techniques that can have a better frequency resolution that FFT-based spectral estimation. Autoregressive (AR) model-based spectral estimation techniques, with emphasis on selection of appropriate sampling rate and AR model order, were implemented to generate high-density 3D DF maps of atrial electrograms (AEGs) in persistent atrial fibrillation (persAF). For each patient, 2048 simultaneous AEGs were recorded for 20.478 s-long segments in the left atrium (LA) and exported for analysis, together with their anatomical locations. After the DFs were identified using AR-based spectral estimation, they were colour coded to produce sequential 3D DF maps. These maps were systematically compared with maps found using the Fourier-based approach. 3D DF maps can be obtained using AR-based spectral estimation after AEGs downsampling (DS) and the resulting maps are very similar to those obtained using FFT-based spectral estimation (mean 90.23 %). There were no significant differences between AR techniques (p = 0.62). The processing time for AR-based approach was considerably shorter (from 5.44 to 5.05 s) when lower sampling frequencies and model order values were used. Higher levels of DS presented higher rates of DF agreement (sampling frequency of 37.5 Hz). We have demonstrated the feasibility of using AR spectral estimation methods for producing 3D DF maps and characterised their differences to the maps produced using the FFT technique, offering an alternative approach for 3D DF computation in human persAF studies.

Using Cognitive Maps to Promote Self-Managed Learning in Online Communities of Inquiry

ERIC Educational Resources Information Center

Peacock, Susi; Cowan, John

2016-01-01

As online learners become more diverse and less well-prepared individually, particular help is required when transitioning into new, online learning environments, requiring engagement in collaborative, community-based educational activities. Cognitive maps provide one tool for tutors to support individuals in navigating the unfamiliar maze of…

Regional geochemistry Bandung Quadrangle West Java: for environmental and resources studies

NASA Astrophysics Data System (ADS)

Sendjaja, Purnama; Baharuddin

2017-06-01

Geochemical mapping based on the stream sediment method has been carried out in the whole of Java Region by the Centre for Geological Survey. The Regional Geochemistry Bandung Quadrangle as part of West Java Region has been mapped in 1:100.000 scale map, base on the Geological Map of Bandung Quadrangle. About 82 stream sediment samples collected and sieved in the 80 mesh sieve fraction during the field work session at 2011. This fraction was prepared and analysed for 30 elements by X-ray fluorescence spectrometry at the Centre for Geological Survey Laboratory. There are some elements indicating significant anomaly in this region, and it is important to determine the present abundance and spatial distribution of the elements for presuming result from natural product or derived from human activities. The volcanic products (Tangkuban Perahu Volcano, Volcanic Rock Complex and Quarternary Volcanic-Alluvial Deposit) are clearly identified on the distribution of As, Ba, Cl, Cu, Zr and La elements. However Mn, Zn, V and Sr are related to precipitation in the Tertiary Sediments, while the influence of human activities are showing from a geochemical map of Cl, Cr, Cu, Pb and Zn that show scattered anomalies localized close to the cities, farming and industries.

A concept mapping approach to guide and understand dissemination and implementation.

PubMed

Green, Amy E; Fettes, Danielle L; Aarons, Gregory A

2012-10-01

Many efforts to implement evidence-based programs do not reach their full potential or fail due to the variety of challenges inherent in dissemination and implementation. This article describes the use of concept mapping-a mixed method strategy-to study implementation of behavioral health innovations and evidence-based practice (EBP). The application of concept mapping to implementation research represents a practical and concise way to identify and quantify factors affecting implementation, develop conceptual models of implementation, target areas to address as part of implementation readiness and active implementation, and foster communication among stakeholders. Concept mapping is described and a case example is provided to illustrate its use in an implementation study. Implications for the use of concept mapping methods in both research and applied settings towards the dissemination and implementation of behavioral health services are discussed.

Terrain classification and land hazard mapping in Kalsi-Chakrata area (Garhwal Himalaya), India

NASA Astrophysics Data System (ADS)

Choubey, Vishnu D.; Litoria, Pradeep K.

Terrain classification and land system mapping of a part of the Garhwal Himalaya (India) have been used to provide a base map for land hazard evaluation, with special reference to landslides and other mass movements. The study was based on MSS images, aerial photographs and 1:50,000 scale maps, followed by detailed field-work. The area is composed of two groups of rocks: well exposed sedimentary Precambrian formations in the Himalayan Main Boundary Thrust Belt and the Tertiary molasse deposits of the Siwaliks. Major tectonic boundaries were taken as the natural boundaries of land systems. A physiographic terrain classification included slope category, forest cover, occurrence of landslides, seismicity and tectonic activity in the area.

Three dimensional characterization of GaN-based light emitting diode grown on patterned sapphire substrate by confocal Raman and photoluminescence spectromicroscopy.

PubMed

Li, Heng; Cheng, Hui-Yu; Chen, Wei-Liang; Huang, Yi-Hsin; Li, Chi-Kang; Chang, Chiao-Yun; Wu, Yuh-Renn; Lu, Tien-Chang; Chang, Yu-Ming

2017-03-30

We performed depth-resolved PL and Raman spectral mappings of a GaN-based LED structure grown on a patterned sapphire substrate (PSS). Our results showed that the Raman mapping in the PSS-GaN heterointerface and the PL mapping in the In x Ga 1-x N/GaN MQWs active layer are spatially correlated. Based on the 3D construction of E 2 (high) Raman peak intensity and frequency shift, V-shaped pits in the MQWs can be traced down to the dislocations originated in the cone tip area of PSS. Detail analysis of the PL peak distribution further revealed that the indium composition in the MQWs is related to the residual strain propagating from the PSS-GaN heterointerface toward the LED surface. Numerical simulation based on the indium composition distribution also led to a radiative recombination rate distribution that shows agreement with the experimental PL intensity distribution in the In x Ga 1-x N/GaN MQWs active layer.

Three dimensional characterization of GaN-based light emitting diode grown on patterned sapphire substrate by confocal Raman and photoluminescence spectromicroscopy

PubMed Central

Li, Heng; Cheng, Hui-Yu; Chen, Wei-Liang; Huang, Yi-Hsin; Li, Chi-Kang; Chang, Chiao-Yun; Wu, Yuh-Renn; Lu, Tien-Chang; Chang, Yu-Ming

2017-01-01

We performed depth-resolved PL and Raman spectral mappings of a GaN-based LED structure grown on a patterned sapphire substrate (PSS). Our results showed that the Raman mapping in the PSS-GaN heterointerface and the PL mapping in the InxGa1−xN/GaN MQWs active layer are spatially correlated. Based on the 3D construction of E2(high) Raman peak intensity and frequency shift, V-shaped pits in the MQWs can be traced down to the dislocations originated in the cone tip area of PSS. Detail analysis of the PL peak distribution further revealed that the indium composition in the MQWs is related to the residual strain propagating from the PSS-GaN heterointerface toward the LED surface. Numerical simulation based on the indium composition distribution also led to a radiative recombination rate distribution that shows agreement with the experimental PL intensity distribution in the InxGa1−xN/GaN MQWs active layer. PMID:28358119

Evaluation of normal swallowing functions by using dynamic high-density surface electromyography maps.

PubMed

Zhu, Mingxing; Yu, Bin; Yang, Wanzhang; Jiang, Yanbing; Lu, Lin; Huang, Zhen; Chen, Shixiong; Li, Guanglin

2017-11-21

Swallowing is a continuous process with substantive interdependencies among different muscles, and it plays a significant role in our daily life. The aim of this study was to propose a novel technique based on high-density surface electromyography (HD sEMG) for the evaluation of normal swallowing functions. A total of 96 electrodes were placed on the front neck to acquire myoelectric signals from 12 healthy subjects while they were performing different swallowing tasks. HD sEMG energy maps were constructed based on the root mean square values to visualize muscular activities during swallowing. The effects of different volumes, viscosities, and head postures on the normal swallowing process were systemically investigated by using the energy maps. The results showed that the HD sEMG energy maps could provide detailed spatial and temporal properties of the muscle electrical activity, and visualize the muscle contractions that closely related to the swallowing function. The energy maps also showed that the swallowing time and effort was also explicitly affected by the volume and viscosity of the bolus. The concentration of the muscular activities shifted to the opposite side when the subjects turned their head to either side. The proposed method could provide an alternative method to physiologically evaluate the dynamic characteristics of normal swallowing and had the advantage of providing a full picture of how different muscle activities cooperate in time and location. The findings from this study suggested that the HD sEMG technique might be a useful tool for fast screening and objective assessment of swallowing disorders or dysphagia.

Digital release of the Alaska Quaternary fault and fold database

NASA Astrophysics Data System (ADS)

Koehler, R. D.; Farrell, R.; Burns, P.; Combellick, R. A.; Weakland, J. R.

2011-12-01

The Alaska Division of Geological & Geophysical Surveys (DGGS) has designed a Quaternary fault and fold database for Alaska in conformance with standards defined by the U.S. Geological Survey for the National Quaternary fault and fold database. Alaska is the most seismically active region of the United States, however little information exists on the location, style of deformation, and slip rates of Quaternary faults. Thus, to provide an accurate, user-friendly, reference-based fault inventory to the public, we are producing a digital GIS shapefile of Quaternary fault traces and compiling summary information on each fault. Here, we present relevant information pertaining to the digital GIS shape file and online access and availability of the Alaska database. This database will be useful for engineering geologic studies, geologic, geodetic, and seismic research, and policy planning. The data will also contribute to the fault source database being constructed by the Global Earthquake Model (GEM), Faulted Earth project, which is developing tools to better assess earthquake risk. We derived the initial list of Quaternary active structures from The Neotectonic Map of Alaska (Plafker et al., 1994) and supplemented it with more recent data where available. Due to the limited level of knowledge on Quaternary faults in Alaska, pre-Quaternary fault traces from the Plafker map are shown as a layer in our digital database so users may view a more accurate distribution of mapped faults and to suggest the possibility that some older traces may be active yet un-studied. The database will be updated as new information is developed. We selected each fault by reviewing the literature and georegistered the faults from 1:250,000-scale paper maps contained in 1970's vintage and earlier bedrock maps. However, paper map scales range from 1:20,000 to 1:500,000. Fault parameters in our GIS fault attribute tables include fault name, age, slip rate, slip sense, dip direction, fault line type (i.e., well constrained, moderately constrained, or inferred), and mapped scale. Each fault is assigned a three-integer CODE, based upon age, slip rate, and how well the fault is located. This CODE dictates the line-type for the GIS files. To host the database, we are developing an interactive web-map application with ArcGIS for Server and the ArcGIS API for JavaScript from Environmental Systems Research Institute, Inc. (Esri). The web-map application will present the database through a visible scale range with each fault displayed at the resolution of the original map. Application functionality includes: search by name or location, identification of fault by manual selection, and choice of base map. Base map options include topographic, satellite imagery, and digital elevation maps available from ArcGIS on-line. We anticipate that the database will be publically accessible from a portal embedded on the DGGS website by the end of 2011.

Altering spatial priority maps via reward-based learning.

PubMed

Chelazzi, Leonardo; Eštočinová, Jana; Calletti, Riccardo; Lo Gerfo, Emanuele; Sani, Ilaria; Della Libera, Chiara; Santandrea, Elisa

2014-06-18

Spatial priority maps are real-time representations of the behavioral salience of locations in the visual field, resulting from the combined influence of stimulus driven activity and top-down signals related to the current goals of the individual. They arbitrate which of a number of (potential) targets in the visual scene will win the competition for attentional resources. As a result, deployment of visual attention to a specific spatial location is determined by the current peak of activation (corresponding to the highest behavioral salience) across the map. Here we report a behavioral study performed on healthy human volunteers, where we demonstrate that spatial priority maps can be shaped via reward-based learning, reflecting long-lasting alterations (biases) in the behavioral salience of specific spatial locations. These biases exert an especially strong influence on performance under conditions where multiple potential targets compete for selection, conferring competitive advantage to targets presented in spatial locations associated with greater reward during learning relative to targets presented in locations associated with lesser reward. Such acquired biases of spatial attention are persistent, are nonstrategic in nature, and generalize across stimuli and task contexts. These results suggest that reward-based attentional learning can induce plastic changes in spatial priority maps, endowing these representations with the "intelligent" capacity to learn from experience. Copyright © 2014 the authors 0270-6474/14/348594-11$15.00/0.

Using low-cost drones to map malaria vector habitats.

PubMed

Hardy, Andy; Makame, Makame; Cross, Dónall; Majambere, Silas; Msellem, Mwinyi

2017-01-14

There is a growing awareness that if we are to achieve the ambitious goal of malaria elimination, we must compliment indoor-based vector control interventions (such as bednets and indoor spraying) with outdoor-based interventions such as larval source management (LSM). The effectiveness of LSM is limited by our capacity to identify and map mosquito aquatic habitats. This study provides a proof of concept for the use of a low-cost (< $1000) drone (DJI Phantom) for mapping water bodies in seven sites across Zanzibar including natural water bodies, irrigated and non-irrigated rice paddies, peri-urban and urban locations. With flying times of less than 30 min for each site, high-resolution (7 cm) georeferenced images were successfully generated for each of the seven sites, covering areas up to 30 ha. Water bodies were readily identifiable in the imagery, as well as ancillary information for planning LSM activities (access routes to water bodies by road and foot) and public health management (e.g. identification of drinking water sources, mapping individual households and the nature of their construction). The drone-based surveys carried out in this study provide a low-cost and flexible solution to mapping water bodies for operational dissemination of LSM initiatives in mosquito vector-borne disease elimination campaigns. Generated orthomosaics can also be used to provide vital information for other public health planning activities.

Network Analysis of Postharvest Senescence Process in Citrus Fruits Revealed by Transcriptomic and Metabolomic Profiling1[OPEN

PubMed Central

Ding, Yuduan; Chang, Jiwei; Ma, Qiaoli; Chen, Lingling; Liu, Shuzhen; Jin, Shuai; Han, Jingwen; Xu, Rangwei; Zhu, Andan; Guo, Jing; Luo, Yi; Xu, Juan; Xu, Qiang; Zeng, YunLiu; Deng, Xiuxin

2015-01-01

Citrus (Citrus spp.), a nonclimacteric fruit, is one of the most important fruit crops in global fruit industry. However, the biological behavior of citrus fruit ripening and postharvest senescence remains unclear. To better understand the senescence process of citrus fruit, we analyzed data sets from commercial microarrays, gas chromatography-mass spectrometry, and liquid chromatography-mass spectrometry and validated physiological quality detection of four main varieties in the genus Citrus. Network-based approaches of data mining and modeling were used to investigate complex molecular processes in citrus. The Citrus Metabolic Pathway Network and correlation networks were constructed to explore the modules and relationships of the functional genes/metabolites. We found that the different flesh-rind transport of nutrients and water due to the anatomic structural differences among citrus varieties might be an important factor that influences fruit senescence behavior. We then modeled and verified the citrus senescence process. As fruit rind is exposed directly to the environment, which results in energy expenditure in response to biotic and abiotic stresses, nutrients are exported from flesh to rind to maintain the activity of the whole fruit. The depletion of internal substances causes abiotic stresses, which further induces phytohormone reactions, transcription factor regulation, and a series of physiological and biochemical reactions. PMID:25802366

NAC Transcription Factor SPEEDY HYPONASTIC GROWTH Regulates Flooding-Induced Leaf Movement in Arabidopsis[W

PubMed Central

Rauf, Mamoona; Arif, Muhammad; Fisahn, Joachim; Xue, Gang-Ping; Balazadeh, Salma; Mueller-Roeber, Bernd

2013-01-01

In rosette plants, root flooding (waterlogging) triggers rapid upward (hyponastic) leaf movement representing an important architectural stress response that critically determines plant performance in natural habitats. The directional growth is based on localized longitudinal cell expansion at the lower (abaxial) side of the leaf petiole and involves the volatile phytohormone ethylene (ET). We report the existence of a transcriptional core unit underlying directional petiole growth in Arabidopsis thaliana, governed by the NAC transcription factor SPEEDY HYPONASTIC GROWTH (SHYG). Overexpression of SHYG in transgenic Arabidopsis thaliana enhances waterlogging-triggered hyponastic leaf movement and cell expansion in abaxial cells of the basal petiole region, while both responses are largely diminished in shyg knockout mutants. Expression of several EXPANSIN and XYLOGLUCAN ENDOTRANSGLYCOSYLASE/HYDROLASE genes encoding cell wall–loosening proteins was enhanced in SHYG overexpressors but lowered in shyg. We identified ACC OXIDASE5 (ACO5), encoding a key enzyme of ET biosynthesis, as a direct transcriptional output gene of SHYG and found a significantly reduced leaf movement in response to root flooding in aco5 T-DNA insertion mutants. Expression of SHYG in shoot tissue is triggered by root flooding and treatment with ET, constituting an intrinsic ET-SHYG-ACO5 activator loop for rapid petiole cell expansion upon waterlogging. PMID:24363315

NAC transcription factor speedy hyponastic growth regulates flooding-induced leaf movement in Arabidopsis.

PubMed

Rauf, Mamoona; Arif, Muhammad; Fisahn, Joachim; Xue, Gang-Ping; Balazadeh, Salma; Mueller-Roeber, Bernd

2013-12-01

In rosette plants, root flooding (waterlogging) triggers rapid upward (hyponastic) leaf movement representing an important architectural stress response that critically determines plant performance in natural habitats. The directional growth is based on localized longitudinal cell expansion at the lower (abaxial) side of the leaf petiole and involves the volatile phytohormone ethylene (ET). We report the existence of a transcriptional core unit underlying directional petiole growth in Arabidopsis thaliana, governed by the NAC transcription factor speedy hyponastic growth (SHYG). Overexpression of SHYG in transgenic Arabidopsis thaliana enhances waterlogging-triggered hyponastic leaf movement and cell expansion in abaxial cells of the basal petiole region, while both responses are largely diminished in shyg knockout mutants. Expression of several expansin and xyloglucan endotransglycosylase/hydrolase genes encoding cell wall-loosening proteins was enhanced in SHYG overexpressors but lowered in shyg. We identified ACC oxidase5 (ACO5), encoding a key enzyme of ET biosynthesis, as a direct transcriptional output gene of SHYG and found a significantly reduced leaf movement in response to root flooding in aco5 T-DNA insertion mutants. Expression of SHYG in shoot tissue is triggered by root flooding and treatment with ET, constituting an intrinsic ET-SHYG-ACO5 activator loop for rapid petiole cell expansion upon waterlogging.

The mature anther-preferentially expressed genes are associated with pollen fertility, pollen germination and anther dehiscence in rice.

PubMed

Ling, Sheng; Chen, Caisheng; Wang, Yang; Sun, Xiaocong; Lu, Zhanhua; Ouyang, Yidan; Yao, Jialing

2015-02-19

The anthers and pollen grains are critical for male fertility and hybrid rice breeding. The development of rice mature anther and pollen consists of multiple continuous stages. However, molecular mechanisms regulating mature anther development were poorly understood. In this study, we have identified 291 mature anther-preferentially expressed genes (OsSTA) in rice based on Affymetrix microarray data. Gene Ontology (GO) analysis indicated that OsSTA genes mainly participated in metabolic and cellular processes that are likely important for rice anther and pollen development. The expression patterns of OsSTA genes were validated using real-time PCR and mRNA in situ hybridizations. Cis-element identification showed that most of the OsSTA genes had the cis-elements responsive to phytohormone regulation. Co-expression analysis of OsSTA genes showed that genes annotated with pectinesterase and calcium ion binding activities were rich in the network, suggesting that OsSTA genes could be involved in pollen germination and anther dehiscence. Furthermore, OsSTA RNAi transgenic lines showed male-sterility and pollen germination defects. The results suggested that OsSTA genes function in rice male fertility, pollen germination and anther dehiscence and established molecular regulating networks that lay the foundation for further functional studies.

A microdroplet cell culture based high frequency somatic embryogenesis system for pigeonpea, Cajanus cajan (L.) Millsp.

PubMed

Kumar, Nagan Udhaya; Gnanaraj, Muniraj; Sindhujaa, Vajravel; Viji, Maluventhen; Manoharan, Kumariah

2015-09-01

A protocol for high frequency production of somatic embryos was worked out in pigeonpea, Cajanus cajan (L.) Millsp. The protocol involved sequential employment of embryogenic callus cultures, low density cell suspension cultures and a novel microdroplet cell culture system. The microdroplet cell cultures involved culture of a single cell in 10 μI of Murashige and Skoog's medium supplemented with phytohormones, growth factors and phospholipid precursors. By employing the microdroplet cell cultures, single cells in isolation were grown into cell clones which developed somatic embryos. Further, 2,4-dichlorophenoxyacetic acid, kinetin, polyethylene glycol, putrescine, spermine, spermidine, choline chloride, ethanolamine and LiCl were supplemented to the low density cell suspension cultures and microdroplet cell cultures to screen for their cell division and somatic embryogenesis activity. Incubation of callus or the inoculum employed for low density cell suspension cultures and microdroplet cell cultures with polyethylene glycol was found critical for induction of somatic embryogenesis. Somatic embryogenesis at a frequency of 1.19, 3.16 and 6.51 per 10(6) cells was achieved in the callus, low density cell suspension cultures and microdroplet cell cultures, respectively. Advantages of employing microdroplet cell cultures for high frequency production of somatic embryos and its application in genetic transformation protocols are discussed.

Salicylic acid, a plant defense hormone, is specifically secreted by a molluscan herbivore.

PubMed

Kästner, Julia; von Knorre, Dietrich; Himanshu, Himanshu; Erb, Matthias; Baldwin, Ian T; Meldau, Stefan

2014-01-01

Slugs and snails are important herbivores in many ecosystems. They differ from other herbivores by their characteristic mucus trail. As the mucus is secreted at the interface between the plants and the herbivores, its chemical composition may play an essential role in plant responses to slug and snail attack. Based on our current knowledge about host-manipulation strategies employed by pathogens and insects, we hypothesized that mollusks may excrete phytohormone-like substances into their mucus. We therefore screened locomotion mucus from thirteen molluscan herbivores for the presence of the plant defense hormones jasmonic acid (JA), salicylic acid (SA) and abscisic acid (ABA). We found that the locomotion mucus of one slug, Deroceras reticulatum, contained significant amounts of SA, a plant hormone that is known to induce resistance to pathogens and to suppress plant immunity against herbivores. None of the other slugs and snails contained SA or any other hormone in their locomotion mucus. When the mucus of D. reticulatum was applied to wounded leaves of A. thaliana, the promotor of the SA-responsive gene pathogenesis related 1 (PR1) was activated, demonstrating the potential of the mucus to regulate plant defenses. We discuss the potential ecological, agricultural and medical implications of this finding.

Salicylic Acid, a Plant Defense Hormone, Is Specifically Secreted by a Molluscan Herbivore

PubMed Central

Kästner, Julia; von Knorre, Dietrich; Himanshu, Himanshu; Erb, Matthias; Baldwin, Ian T.; Meldau, Stefan

2014-01-01

Slugs and snails are important herbivores in many ecosystems. They differ from other herbivores by their characteristic mucus trail. As the mucus is secreted at the interface between the plants and the herbivores, its chemical composition may play an essential role in plant responses to slug and snail attack. Based on our current knowledge about host-manipulation strategies employed by pathogens and insects, we hypothesized that mollusks may excrete phytohormone-like substances into their mucus. We therefore screened locomotion mucus from thirteen molluscan herbivores for the presence of the plant defense hormones jasmonic acid (JA), salicylic acid (SA) and abscisic acid (ABA). We found that the locomotion mucus of one slug, Deroceras reticulatum, contained significant amounts of SA, a plant hormone that is known to induce resistance to pathogens and to suppress plant immunity against herbivores. None of the other slugs and snails contained SA or any other hormone in their locomotion mucus. When the mucus of D. reticulatum was applied to wounded leaves of A. thaliana, the promotor of the SA-responsive gene pathogenesis related 1 (PR1) was activated, demonstrating the potential of the mucus to regulate plant defenses. We discuss the potential ecological, agricultural and medical implications of this finding. PMID:24466122

ICA model order selection of task co-activation networks.

PubMed

Ray, Kimberly L; McKay, D Reese; Fox, Peter M; Riedel, Michael C; Uecker, Angela M; Beckmann, Christian F; Smith, Stephen M; Fox, Peter T; Laird, Angela R

2013-01-01

Independent component analysis (ICA) has become a widely used method for extracting functional networks in the brain during rest and task. Historically, preferred ICA dimensionality has widely varied within the neuroimaging community, but typically varies between 20 and 100 components. This can be problematic when comparing results across multiple studies because of the impact ICA dimensionality has on the topology of its resultant components. Recent studies have demonstrated that ICA can be applied to peak activation coordinates archived in a large neuroimaging database (i.e., BrainMap Database) to yield whole-brain task-based co-activation networks. A strength of applying ICA to BrainMap data is that the vast amount of metadata in BrainMap can be used to quantitatively assess tasks and cognitive processes contributing to each component. In this study, we investigated the effect of model order on the distribution of functional properties across networks as a method for identifying the most informative decompositions of BrainMap-based ICA components. Our findings suggest dimensionality of 20 for low model order ICA to examine large-scale brain networks, and dimensionality of 70 to provide insight into how large-scale networks fractionate into sub-networks. We also provide a functional and organizational assessment of visual, motor, emotion, and interoceptive task co-activation networks as they fractionate from low to high model-orders.

ICA model order selection of task co-activation networks

PubMed Central

Ray, Kimberly L.; McKay, D. Reese; Fox, Peter M.; Riedel, Michael C.; Uecker, Angela M.; Beckmann, Christian F.; Smith, Stephen M.; Fox, Peter T.; Laird, Angela R.

2013-01-01

Independent component analysis (ICA) has become a widely used method for extracting functional networks in the brain during rest and task. Historically, preferred ICA dimensionality has widely varied within the neuroimaging community, but typically varies between 20 and 100 components. This can be problematic when comparing results across multiple studies because of the impact ICA dimensionality has on the topology of its resultant components. Recent studies have demonstrated that ICA can be applied to peak activation coordinates archived in a large neuroimaging database (i.e., BrainMap Database) to yield whole-brain task-based co-activation networks. A strength of applying ICA to BrainMap data is that the vast amount of metadata in BrainMap can be used to quantitatively assess tasks and cognitive processes contributing to each component. In this study, we investigated the effect of model order on the distribution of functional properties across networks as a method for identifying the most informative decompositions of BrainMap-based ICA components. Our findings suggest dimensionality of 20 for low model order ICA to examine large-scale brain networks, and dimensionality of 70 to provide insight into how large-scale networks fractionate into sub-networks. We also provide a functional and organizational assessment of visual, motor, emotion, and interoceptive task co-activation networks as they fractionate from low to high model-orders. PMID:24339802

The comparative effect of individually-generated vs. collaboratively-generated computer-based concept mapping on science concept learning

NASA Astrophysics Data System (ADS)

Kwon, So Young

Using a quasi-experimental design, the researcher investigated the comparative effects of individually-generated and collaboratively-generated computer-based concept mapping on middle school science concept learning. Qualitative data were analyzed to explain quantitative findings. One hundred sixty-one students (74 boys and 87 girls) in eight, seventh grade science classes at a middle school in Southeast Texas completed the entire study. Using prior science performance scores to assure equivalence of student achievement across groups, the researcher assigned the teacher's classes to one of the three experimental groups. The independent variable, group, consisted of three levels: 40 students in a control group, 59 students trained to individually generate concept maps on computers, and 62 students trained to collaboratively generate concept maps on computers. The dependent variables were science concept learning as demonstrated by comprehension test scores, and quality of concept maps created by students in experimental groups as demonstrated by rubric scores. Students in the experimental groups received concept mapping training and used their newly acquired concept mapping skills to individually or collaboratively construct computer-based concept maps during study time. The control group, the individually-generated concept mapping group, and the collaboratively-generated concept mapping group had equivalent learning experiences for 50 minutes during five days, excepting that students in a control group worked independently without concept mapping activities, students in the individual group worked individually to construct concept maps, and students in the collaborative group worked collaboratively to construct concept maps during their study time. Both collaboratively and individually generated computer-based concept mapping had a positive effect on seventh grade middle school science concept learning but neither strategy was more effective than the other. However, the students who collaboratively generated concept maps created significantly higher quality concept maps than those who individually generated concept maps. The researcher concluded that the concept mapping software, Inspiration(TM), fostered construction of students' concept maps individually or collaboratively for science learning and helped students capture their evolving creative ideas and organize them for meaningful learning. Students in both the individual and the collaborative concept mapping groups had positive attitudes toward concept mapping using Inspiration(TM) software.

Comprehensive transcriptome analysis of phytohormone biosyntheis and signaling genes in the flowers of Chinese chinquapin (Castanea henryi)

USDA-ARS?s Scientific Manuscript database

The Chinese chinquapin (Castanea henryi) nut provides a rich source of starch and nutrient elements as food and feed, but its yield is restricted by a low ratio of female to male flowers (1/2000-1/3000). Little is known about the developmental programs underlying the sex differentiation of the flowe...

CTR1 phosphorylates the central regulator EIN2 to control ethylene hormone signaling from the ER membrane to the nucleus in Arabidopsis

USDA-ARS?s Scientific Manuscript database

The gaseous phytohormone ethylene (C2H4) mediates numerous aspects of growth and development. Genetic analysis has identified a number of critical elements in the ethylene signaling (1), but how these elements interact biochemically to transduce the signal from the ethylene receptor complex at the e...

Functional analysis of a tomato salicylic acid methyl transferase and its role in synthesis of the flavor volatile methyl salicylate

USDA-ARS?s Scientific Manuscript database

Methyl salicylate (MeSA) is a volatile plant secondary metabolite that is an important contributor to taste and scent of many fruits and flowers. It is synthesized from salicylic acid (SA), a phytohormone that contributes to plant pathogen defense. MeSA is synthesized by members of a family of O-met...

Map showing seismicity and sandblows in the vicinity of New Madrid, Missouri

USGS Publications Warehouse

Rhea, B. Susan; Tarr, Arthur C.; Wheeler, Russell L.

1994-01-01

This is one of a series of five seismotectic maps of the seismically active New Madrid, Missouri, area (table 1; Wheeler and others, 1992). The map area centers near the sites of three great earthquakes that struck during the winter of 1811-12 (Fuller, 1912; Nuttli, 1973). These earthquakes and continuing subsequent seismicity rank the New Madrid area with Cherlevoix, Quebec, as the two most seismically active areas in North America east of the Rocky Mountains. The threat posed by New Madrid seismicity to the central United States makes the area the focus of many investigations (for examples, Heyl and McKeown, 1978; McKeown and Pakiser, 1982; Algemissen and Hopper, 1984; Hamilton and Johnston, 1990; Applied Technology Council, 1991; Johnston and others, 1992). The map area includes the most intense seismic activity in the New Madrid region. A seismotectic map shows some of the geologic and geophysical information needed to assess seismic hazard (Hadley and Devine, 1974; Pavoni, 1985). A previous seismotectonic map of the central Mississippi River valley (Heyl and McKeown, 1978) has had wide use for planning field surveys, as a base map for plotting data collected during single investigations, and for compiling a range of information. Since 1978 numcrous researchers have greatly advanced our knowledge of the geology and geophysics of the central Mississippi Valley. The New Madrid seismotectonic map folio updates approximately the south-central sixth of the central Mississippi Valley seismotectonic map of Heyl and McKeown (1978).

Low temperature sensing in tulip (Tulipa gesneriana L.) is mediated through an increased response to auxin.

PubMed

Rietveld, P L; Wilkinson, C; Franssen, H M; Balk, P A; van der Plas, L H; Weisbeek, P J; Douwe de Boer, A

2000-03-01

Tulip (Tulipa gesneriana L.) is a bulbous plant species that requires a period of low temperature for proper growth and flowering. The mechanism of sensing the low temperature period is unknown. The study presented in this paper shows that the essential developmental change in tulip bulbs during cold treatment is an increase in sensitivity to the phytohormone auxin. This is demonstrated using a model system consisting of isolated internodes grown on tissue culture medium containing different combinations of the phytohormones auxin and gibberellin. Using mathematical modelling, equations taken from the field of enzyme kinetics were fitted through the data. By doing so it became apparent that longer periods of low temperature resulted in an increased maximum response at a lower auxin concentration. Besides the cold treatment, gibberellin also enhances the response to auxin in the internodes in this in vitro system. A working model describing the relationship between the cold requirement, gibberellin action and auxin sensitivity is put forward. Possible analogies with other cold-requiring processes such as vernalization and stratification, and the interaction of auxin and gibberellin in the stalk elongation process in other plant species are discussed.

A morel improved growth and suppressed Fusarium infection in sweet corn.

PubMed

Yu, Dan; Bu, Fangfang; Hou, Jiaojiao; Kang, Yongxiang; Yu, Zhongdong

2016-12-01

A post-fire morel collected from Populus simonii stands in Mt. Qingling was identified as Morchella crassipes Mes-20 by using nuclear ribosomal DNA internal transcribed spacer phylogeny. It was inoculated into sweet corn to observe colonized roots in purified culture and in greenhouse experiments. The elongation and maturation zones of sweet corn were remarkably colonized at the cortex intercellular and intracellular cells, vessel cells, and around the Casparian strip, forming ectendomycorrhiza-like structures. Colonization was also observed in the zone of cell division proximal to the root cap. Greenhouse assays with sweet corn showed that this morel stimulated the development of the root system and significantly increased the dry root biomass. M. crassipes also significantly reduced the incidence of Fusarium verticillioides in the kernels of mature ears when inoculated into young ears before Fusarium inoculation and prevented Fusarium infection in corn ears compared with that of the control in the greenhouse. When grown under axenic conditions, M. crassipes produced the phytohormones abscisic acid, indole-3-acetic acid, and salicylic acid. The benefits to plants elicited by M. crassipes may result from these phytohormones which may improve the drought resistance, biomass growth and resistance to Fusarium.

An effector of apple proliferation phytoplasma targets TCP transcription factors-a generalized virulence strategy of phytoplasma?

PubMed

Janik, Katrin; Mithöfer, Axel; Raffeiner, Margot; Stellmach, Hagen; Hause, Bettina; Schlink, Katja

2017-04-01

The plant pathogen Candidatus Phytoplasma mali (P. mali) is the causative agent of apple proliferation, a disease of increasing importance in apple-growing areas within Europe. Despite its economic importance, little is known about the molecular mechanisms of disease manifestation within apple trees. In this study, we identified two TCP (TEOSINTE BRANCHED/CYCLOIDEA/PROLIFERATING CELL FACTOR) transcription factors of Malus x domestica as binding partners of the P. mali SAP11-like effector ATP_00189. Phytohormone analyses revealed an effect of P. mali infection on jasmonates, salicylic acid and abscisic acid levels, showing that P. mali affects phytohormonal levels in apple trees, which is in line with the functions of the effector assumed from its binding to TCP transcription factors. To our knowledge, this is the first characterization of the molecular targets of a P. mali effector and thus provides the basis to better understand symptom development and disease progress during apple proliferation. As SAP11 homologues are found in several Phytoplasma species infecting a broad range of different plants, SAP11-like proteins seem to be key players in phytoplasmal infection. © 2016 BSPP AND JOHN WILEY & SONS LTD.

Spatial Regulation of Root Growth: Placing the Plant TOR Pathway in a Developmental Perspective

PubMed Central

Barrada, Adam; Montané, Marie-Hélène; Robaglia, Christophe; Menand, Benoît

2015-01-01

Plant cells contain specialized structures, such as a cell wall and a large vacuole, which play a major role in cell growth. Roots follow an organized pattern of development, making them the organs of choice for studying the spatio-temporal regulation of cell proliferation and growth in plants. During root growth, cells originate from the initials surrounding the quiescent center, proliferate in the division zone of the meristem, and then increase in length in the elongation zone, reaching their final size and differentiation stage in the mature zone. Phytohormones, especially auxins and cytokinins, control the dynamic balance between cell division and differentiation and therefore organ size. Plant growth is also regulated by metabolites and nutrients, such as the sugars produced by photosynthesis or nitrate assimilated from the soil. Recent literature has shown that the conserved eukaryotic TOR (target of rapamycin) kinase pathway plays an important role in orchestrating plant growth. We will summarize how the regulation of cell proliferation and cell expansion by phytohormones are at the heart of root growth and then discuss recent data indicating that the TOR pathway integrates hormonal and nutritive signals to orchestrate root growth. PMID:26295391

Mechanisms and evolution of plant resistance to aphids.

PubMed

Züst, Tobias; Agrawal, Anurag A

2016-01-06

Aphids are important herbivores of both wild and cultivated plants. Plants rely on unique mechanisms of recognition, signalling and defence to cope with the specialized mode of phloem feeding by aphids. Aspects of the molecular mechanisms underlying aphid-plant interactions are beginning to be understood. Recent advances include the identification of aphid salivary proteins involved in host plant manipulation, and plant receptors involved in aphid recognition. However, a complete picture of aphid-plant interactions requires consideration of the ecological outcome of these mechanisms in nature, and the evolutionary processes that shaped them. Here we identify general patterns of resistance, with a special focus on recognition, phytohormonal signalling, secondary metabolites and induction of plant resistance. We discuss how host specialization can enable aphids to co-opt both the phytohormonal responses and defensive compounds of plants for their own benefit at a local scale. In response, systemically induced resistance in plants is common and often involves targeted responses to specific aphid species or even genotypes. As co-evolutionary adaptation between plants and aphids is ongoing, the stealthy nature of aphid feeding makes both the mechanisms and outcomes of these interactions highly distinct from those of other herbivore-plant interactions.

Approaches in modulating proline metabolism in plants for salt and drought stress tolerance: Phytohormones, mineral nutrients and transgenics.

PubMed

Per, Tasir S; Khan, Nafees A; Reddy, Palakolanu Sudhakar; Masood, Asim; Hasanuzzaman, Mirza; Khan, M Iqbal R; Anjum, Naser A

2017-06-01

Major abiotic stress factors such as salt and drought adversely affect important physiological processes and biochemical mechanisms and cause severe loss in crop productivity worldwide. Plants develop various strategies to stand healthy against these stress factors. The accumulation of proline (Pro) is one of the striking metabolic responses of plants to salt and drought stress. Pro biosynthesis and signalling contribute to the redox balance of cell under normal and stressful conditions. However, literature is meager on the sustainable strategies potentially fit for modulating Pro biosynthesis and production in stressed plants. Considering the recent literature, this paper in its first part overviews Pro biosynthesis and transport in plants and also briefly highlights the significance of Pro in plant responses to salt and drought stress. Secondly, this paper discusses mechanisms underlying the regulation of Pro metabolism in salt and drought-exposed plant via phytohormones, mineral nutrients and transgenic approaches. The outcome of the studies may give new opportunities in modulating Pro metabolism for improving plant tolerance to salt and drought stress and benefit sustainable agriculture. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Transient heat stress compromises the resistance of wheat (Poales: Poaceae) seedlings to Hessian fly (Diptera: Cecidomyiidae) infestation.

PubMed

Currie, Yaleaka; Moch, John; Underwood, Joshua; Kharabsheh, Hamzah; Quesenberry, Amy; Miyagi, Risa; Thomas, Carolyn; Boney, Melanie; Woods, Samantha; Chen, Ming-Shun; Zhu, Lieceng

2014-02-01

Heat stress exerts a profound impact on the resistance of plants to parasites. In this research, we investigated the impact of an acute transient heat stress on the resistance of the wheat line 'Molly,' which contains the R gene H13, to an avirulent Hessian fly (Mayetiola destructor (Say)) population. We found that a significant portion of Molly seedlings stressed at 40 degrees C for 6 h during or after the initial Hessian fly larval attack became susceptible to otherwise avirulent insects, whereas unstressed control plants remained 100% resistant. Specifically, 77.8, 73.3, 83.3, and 46.7% of plants heat stressed at 0, 6,12, and 24 h, respectively, after the initial larval attack became susceptible. Biochemical analysis revealed that heat stress caused a transient decrease in 12-oxo-phytodienoic acid, but an increase in salicylic acid accumulation in Molly plants. The change in phytohormones after heat stress and Hessian fly infestation was not observed in 'Newton,' a near-isogenic but Hessian fly susceptible wheat line. Instead, heat stress caused a relatively prolonged reduction in palmitoleic acid. The role of phytohormones in heat-induced loss of wheat resistance was discussed.

The boosted biomass and lipid accumulation in Chlorella vulgaris by supplementation of synthetic phytohormone analogs.

PubMed

Liu, Tingting; Liu, Fei; Wang, Chao; Wang, Zhenyao; Li, Yuqin

2017-05-01

This study attempted at maximizing biomass and lipid accumulation in Chlorella vulgaris by supplementation of natural abscisic acid (ABA) or synthetic 2,4-dichlorophenoxyacetic acid (2,4-D) and 1-naphthaleneacetic acid (NAA) hormone analogs. Amongst three tested additives, NAA-treatment performed remarkable promoting effect on cell growth and lipid biosynthesis. The favorable lipid productivity (418.6mg/L/d) of NAA-treated cells showed 1.48 and 2.24 times more than that of 2,4-D and ABA. NAA-treatment also positively modified the proportions of saturated (C16:0 and C18:0) and monounsaturated fatty acids (C18:1) which were prone to high-quality biofuels-making. Further, NAA-treatment manipulated endogenous phytohormones metabolism leading to the elevated levels of indole-3-acetic acid, jasmonic acid, and salicylic acid and such hormone accumulation might be indispensable for signal transduction in regulating cell growth and lipid biosynthesis in microalgae. In addition, the economic-feasibility and eco-friendly estimation of NAA additive indicated the higher possibilities in developing affordable and scalable microalgal lipids for biofuels. Copyright © 2017 Elsevier Ltd. All rights reserved.

Entrainment and high-density three-dimensional mapping in right atrial macroreentry provide critical complementary information: Entrainment may unmask "visual reentry" as passive.

PubMed

Pathik, Bhupesh; Lee, Geoffrey; Nalliah, Chrishan; Joseph, Stephen; Morton, Joseph B; Sparks, Paul B; Sanders, Prashanthan; Kistler, Peter M; Kalman, Jonathan M

2017-10-01

With the recent advent of high-density (HD) 3-dimensional (3D) mapping, the utility of entrainment is uncertain. However, the limitations of visual representation and interpretation of these high-resolution 3D maps are unclear. The purpose of this study was to determine the strengths and limitations of both HD 3D mapping and entrainment mapping during mapping of right atrial macroreentry. Fifteen patients were studied. The number and type of circuits accounting for ≥90% of the tachycardia cycle length using HD 3D mapping were verified using systematic entrainment mapping. Entrainment sites with an unexpectedly long postpacing interval despite proximity to the active circuit were evaluated. Based on HD 3D mapping, 27 circuits were observed: 12 peritricuspid, 2 upper loop reentry, 10 lower loop reentry, and 3 lateral wall circuits. With entrainment, 17 of the 27 circuits were active: all 12 peritricuspid and 2 upper loop reentry. However, lower loop reentry was confirmed in only 3 of 10, and none of the 3 lateral wall circuits were present. Mean percentage of tachycardia cycle length covered by active circuits was 98% ± 1% vs 97% ± 2% for passive circuits (P = .09). None of the 345 entrainment runs terminated tachycardia or changed tachycardia mechanism. In 8 of 15 patients, 13 examples of unexpectedly long postpacing interval were observed at entrainment sites located distal to localized zones of slow conduction seen on HD 3D mapping. Using HD 3D mapping, "visual reentry" may be due to passive circuitous propagation rather than a critical reentrant circuit. HD 3D mapping provides new insights into regional conduction and helps explain unusual entrainment phenomena. Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Scoping of Flood Hazard Mapping Needs for Penobscot County, Maine

USGS Publications Warehouse

Schalk, Charles W.; Dudley, Robert W.

2007-01-01

Background The Federal Emergency Management Agency (FEMA) developed a plan in 1997 to modernize the FEMA flood mapping program. FEMA flood maps delineate flood hazard areas in support of the National Flood Insurance Program (NFIP). FEMA's plan outlined the steps necessary to update FEMA's flood maps for the nation to a seamless digital format and streamline FEMA's operations in raising public awareness of the importance of the maps and responding to requests to revise them. The modernization of flood maps involves conversion of existing information to digital format and integration of improved flood hazard data as needed. To determine flood mapping modernization needs, FEMA has established specific scoping activities to be done on a county-by-county basis for identifying and prioritizing requisite flood-mapping activities for map modernization. The U.S. Geological Survey (USGS), in cooperation with FEMA and the Maine State Planning Office Floodplain Management Program (MFMP), began scoping work in 2006 for Penobscot County. Scoping activities included assembling existing data and map needs information for communities in Penobscot County, documentation of data, contacts, community meetings, and prioritized mapping needs in a final scoping report (this document), and updating the Mapping Needs Update Support System (MNUSS) Database with information gathered during the scoping process. As of 2007, the average age of the FEMA floodplain maps in Penobscot County, Maine, is 22 years, based on the most recent revisions to the maps. Because the revisions did not affect all the map panels in each town, however, the true average date probably is more than 22 years. Many of the studies were published in the mid-1980s. Since the studies were completed, development has occurred in many of the watersheds, and the characteristics of the watersheds have changed with time. Therefore, many of the older studies may not depict current conditions nor accurately estimate risk in terms of flood heights or flood mapping.

Exogenous Methyl Jasmonate and Salicylic Acid Induce Subspecies-Specific Patterns of Glucosinolate Accumulation and Gene Expression in Brassica oleracea L.

PubMed

Yi, Go-Eun; Robin, Arif Hasan Khan; Yang, Kiwoung; Park, Jong-In; Hwang, Byung Ho; Nou, Ill-Sup

2016-10-24

Glucosinolates have anti-carcinogenic properties. In the recent decades, the genetics of glucosinolate biosynthesis has been widely studied, however, the expression of specific genes involved in glucosinolate biosynthesis under exogenous phytohormone treatment has not been explored at the subspecies level in Brassica oleracea . Such data are vital for strategies aimed at selective exploitation of glucosinolate profiles. This study quantified the expression of 38 glucosinolate biosynthesis-related genes in three B. oleracea subspecies, namely cabbage, broccoli and kale, and catalogued associations between gene expression and increased contents of individual glucosinolates under methyl jasmonate (MeJA) and salicylic acid (SA) treatments. Glucosinolate accumulation and gene expression in response to phytohormone elicitation was subspecies specific. For instance, cabbage leaves showed enhanced accumulation of the aliphatic glucoiberin, progoitrin, sinigrin and indolic neoglucobrassicin under both MeJA and SA treatment. MeJA treatment induced strikingly higher accumulation of glucobrassicin (GBS) in cabbage and kale and of neoglucobrassicin (NGBS) in broccoli compared to controls. Notably higher expression of ST5a (Bol026200), CYP81F1 (Bol028913, Bol028914) and CYP81F4 genes was associated with significantly higher GBS accumulation under MeJA treatment compared to controls in all three subspecies. CYP81F4 genes, trans-activated by MYB34 genes, were expressed at remarkably high levels in all three subspecies under MeJA treatment, which also induced in higher indolic NGBS accumulation in all three subspecies. Remarkably higher expression of MYB28 (Bol036286), ST5b , ST5c , AOP2 , FMOGS-OX5 (Bol031350) and GSL-OH (Bol033373) was associated with much higher contents of aliphatic glucosinolates in kale leaves compared to the other two subspecies. The genes expressed highly could be utilized in strategies to selectively increase glucosinolate compounds in B. oleracea subspecies. These results promote efforts to develop genotypes of B. oleracea and other species with enhanced levels of desired glucosinolates.

Transcriptome profiling of the floral buds and discovery of genes related to sex-differentiation in the dioecious cucurbit Coccinia grandis (L.) Voigt.

PubMed

Mohanty, Jatindra Nath; Nayak, Sanghamitra; Jha, Sumita; Joshi, Raj Kumar

2017-08-30

Dioecious species offer an inclusive structure to study the molecular basis of sexual dimorphism in angiosperms. Despite having a small genome and heteromorphic sex chromosomes, Coccinia grandis is a highly neglected dioecious species with little information available on its physical state, genetic orientation and key sex-defining elements. In the present study, we performed RNA-Seq and DGE analysis of male (MB) and female (FB) buds in C. grandis to gain insights into the molecular basis of sex determination in this plant. De novo assembly of 75 million clean reads resulted in 72,479 unigenes for male library and 63,308 unigenes for female library with a mean length of 736bp. 61,458 (85.57%) unigenes displayed significant similarity with protein sequences from publicly available databases. Comparative transcriptome analyses revealed 1410 unigenes as differentially expressed (DEGs) between MB and FB samples. A consistent correlation between the expression levels of DEGs was observed for the RNA-Seq pattern and qRT-PCR validation. Functional annotation showed high enrichment of DEGs involved in phytohormone biosynthesis, hormone signaling and transduction, transcriptional regulation and methyltransferase activity. High induction of hormone responsive genes such as ARF6, ACC synthase1, SNRK2 and BRI1-associated receptor kinase 1 (BAK1) suggest that multiple phytohormones and their signaling crosstalk play crucial role in sex determination in this species. Beside, the transcription factors such as zinc fingers, homeodomain leucine zippers and MYBs were identified as major determinants of male specific expression. Moreover, the detection of multiple DEGs as the miRNA target site implies that a small RNA mediated gene silencing cascade may also be regulating gender differentiation in C. grandis. Overall, the present transcriptome resources provide us a large number of DEGs involved in sex expression and could form the groundwork for unravelling the molecular mechanism of sex determination in C. grandis. Copyright © 2017 Elsevier B.V. All rights reserved.

Rice PLASTOCHRON genes regulate leaf maturation downstream of the gibberellin signal transduction pathway.

PubMed

Mimura, Manaki; Nagato, Yasuo; Itoh, Jun-Ichi

2012-05-01

Rice PLASTOCHRON 1 (PLA1) and PLA2 genes regulate leaf maturation and plastochron, and their loss-of-function mutants exhibit small organs and rapid leaf emergence. They encode a cytochrome P450 protein CYP78A11 and an RNA-binding protein, respectively. Their homologs in Arabidopsis and maize are also associated with plant development/organ size. Despite the importance of PLA genes in plant development, their molecular functions remain unknown. Here, we investigated how PLA1 and PLA2 genes are related to phytohormones. We found that gibberellin (GA) is the major phytohormone that promotes PLA1 and PLA2 expression. GA induced PLA1 and PLA2 expression, and conversely the GA-inhibitor uniconazole suppressed PLA1 and PLA2 expression. In pla1-4 and pla2-1 seedlings, expression levels of GA biosynthesis genes and the signal transduction gene were similar to those in wild-type seedlings. GA treatment slightly down-regulated the GA biosynthesis gene GA20ox2 and up-regulated the GA-catabolizing gene GA2ox4, whereas the GA biosynthesis inhibitor uniconazole up-regulated GA20ox2 and down-regulated GA2ox4 both in wild-type and pla mutants, suggesting that the GA feedback mechanism is not impaired in pla1 and pla2. To reveal how GA signal transduction affects the expression of PLA1 and PLA2, PLA expression in GA-signaling mutants was examined. In GA-insensitive mutant, gid1 and less-sensitive mutant, Slr1-d1, PLA1 and PLA2 expression was down-regulated. On the other hand, the expression levels of PLA1 and PLA2 were highly enhanced in a GA-constitutive-active mutant, slr1-1, causing ectopic overexpression. These results indicate that both PLA1 and PLA2 act downstream of the GA signal transduction pathway to regulate leaf development.

Transcriptome, carbohydrate, and phytohormone analysis of Petunia hybrida reveals a complex disturbance of plant functional integrity under mild chilling stress

PubMed Central

Bauerfeind, Martin Andreas; Winkelmann, Traud; Franken, Philipp; Druege, Uwe

2015-01-01

Cultivation of chilling-tolerant ornamental crops at lower temperature could reduce the energy demands of heated greenhouses. To provide a better understanding of how sub-optimal temperatures (12°C vs. 16°C) affect growth of the sensitive Petunia hybrida cultivar ‘SweetSunshine Williams’, the transcriptome, carbohydrate metabolism, and phytohormone homeostasis were monitored in aerial plant parts over 4 weeks by use of a microarray, enzymatic assays and GC-MS/MS. The data revealed three consecutive phases of chilling response. The first days were marked by a strong accumulation of sugars, particularly in source leaves, preferential up-regulation of genes in the same tissue and down-regulation of several genes in the shoot apex, especially those involved in the abiotic stress response. The midterm phase featured a partial normalization of carbohydrate levels and gene expression. After 3 weeks of chilling exposure, a new stabilized balance was established. Reduced hexose levels in the shoot apex, reduced ratios of sugar levels between the apex and source leaves and a higher apical sucrose/hexose ratio, associated with decreased activity and expression of cell wall invertase, indicate that prolonged chilling induced sugar accumulation in source leaves at the expense of reduced sugar transport to and reduced sucrose utilization in the shoot. This was associated with reduced levels of indole-3-acetic acid and abscisic acid in the apex and high numbers of differentially, particularly up-regulated genes, especially in the source leaves, including those regulating histones, ethylene action, transcription factors, and a jasmonate-ZIM-domain protein. Transcripts of one Jumonji C domain containing protein and one expansin accumulated in source leaves throughout the chilling period. The results reveal a dynamic and complex disturbance of plant function in response to mild chilling, opening new perspectives for the comparative analysis of differently tolerant cultivars. PMID:26284099

Transcriptome, carbohydrate, and phytohormone analysis of Petunia hybrida reveals a complex disturbance of plant functional integrity under mild chilling stress.

PubMed

Bauerfeind, Martin Andreas; Winkelmann, Traud; Franken, Philipp; Druege, Uwe

2015-01-01

Cultivation of chilling-tolerant ornamental crops at lower temperature could reduce the energy demands of heated greenhouses. To provide a better understanding of how sub-optimal temperatures (12°C vs. 16°C) affect growth of the sensitive Petunia hybrida cultivar 'SweetSunshine Williams', the transcriptome, carbohydrate metabolism, and phytohormone homeostasis were monitored in aerial plant parts over 4 weeks by use of a microarray, enzymatic assays and GC-MS/MS. The data revealed three consecutive phases of chilling response. The first days were marked by a strong accumulation of sugars, particularly in source leaves, preferential up-regulation of genes in the same tissue and down-regulation of several genes in the shoot apex, especially those involved in the abiotic stress response. The midterm phase featured a partial normalization of carbohydrate levels and gene expression. After 3 weeks of chilling exposure, a new stabilized balance was established. Reduced hexose levels in the shoot apex, reduced ratios of sugar levels between the apex and source leaves and a higher apical sucrose/hexose ratio, associated with decreased activity and expression of cell wall invertase, indicate that prolonged chilling induced sugar accumulation in source leaves at the expense of reduced sugar transport to and reduced sucrose utilization in the shoot. This was associated with reduced levels of indole-3-acetic acid and abscisic acid in the apex and high numbers of differentially, particularly up-regulated genes, especially in the source leaves, including those regulating histones, ethylene action, transcription factors, and a jasmonate-ZIM-domain protein. Transcripts of one Jumonji C domain containing protein and one expansin accumulated in source leaves throughout the chilling period. The results reveal a dynamic and complex disturbance of plant function in response to mild chilling, opening new perspectives for the comparative analysis of differently tolerant cultivars.

Magnetoencephalographic Mapping of Epileptic Spike Population Using Distributed Source Analysis: Comparison With Intracranial Electroencephalographic Spikes.

PubMed

Tanaka, Naoaki; Papadelis, Christos; Tamilia, Eleonora; Madsen, Joseph R; Pearl, Phillip L; Stufflebeam, Steven M

2018-04-27

This study evaluates magnetoencephalographic (MEG) spike population as compared with intracranial electroencephalographic (IEEG) spikes using a quantitative method based on distributed source analysis. We retrospectively studied eight patients with medically intractable epilepsy who had an MEG and subsequent IEEG monitoring. Fifty MEG spikes were analyzed in each patient using minimum norm estimate. For individual spikes, each vertex in the source space was considered activated when its source amplitude at the peak latency was higher than a threshold, which was set at 50% of the maximum amplitude over all vertices. We mapped the total count of activation at each vertex. We also analyzed 50 IEEG spikes in the same manner over the intracranial electrodes and created the activation count map. The location of the electrodes was obtained in the MEG source space by coregistering postimplantation computed tomography to MRI. We estimated the MEG- and IEEG-active regions associated with the spike populations using the vertices/electrodes with a count over 25. The activation count maps of MEG spikes demonstrated the localization associated with the spike population by variable count values at each vertex. The MEG-active region overlapped with 65 to 85% of the IEEG-active region in our patient group. Mapping the MEG spike population is valid for demonstrating the trend of spikes clustering in patients with epilepsy. In addition, comparison of MEG and IEEG spikes quantitatively may be informative for understanding their relationship.

Developing a systems-based framework of the factors influencing dietary and physical activity behaviours in ethnic minority populations living in Europe - a DEDIPAC study.

PubMed

Holdsworth, Michelle; Nicolaou, Mary; Langøien, Lars Jørun; Osei-Kwasi, Hibbah Araba; Chastin, Sebastien F M; Stok, F Marijn; Capranica, Laura; Lien, Nanna; Terragni, Laura; Monsivais, Pablo; Mazzocchi, Mario; Maes, Lea; Roos, Gun; Mejean, Caroline; Powell, Katie; Stronks, Karien

2017-11-07

Some ethnic minority populations have a higher risk of non-communicable diseases than the majority European population. Diet and physical activity behaviours contribute to this risk, shaped by a system of inter-related factors. This study mapped a systems-based framework of the factors influencing dietary and physical activity behaviours in ethnic minority populations living in Europe, to inform research prioritisation and intervention development. A concept mapping approach guided by systems thinking was used: i. Preparation (protocol and terminology); ii. Generating a list of factors influencing dietary and physical activity behaviours in ethnic minority populations living in Europe from evidence (systematic mapping reviews) and 'eminence' (89 participants from 24 academic disciplines via brainstorming, an international symposium and expert review) and; iii. Seeking consensus on structuring, rating and clustering factors, based on how they relate to each other; and iv. Interpreting/utilising the framework for research and interventions. Similar steps were undertaken for frameworks developed for the majority European population. Seven distinct clusters emerged for dietary behaviour (containing 85 factors) and 8 for physical activity behaviours (containing 183 factors). Four clusters were similar across behaviours: Social and cultural environment; Social and material resources; Psychosocial; and Migration context. Similar clusters of factors emerged in the frameworks for diet and physical activity behaviours of the majority European population, except for 'migration context'. The importance of factors across all clusters was acknowledged, but their relative importance differed for ethnic minority populations compared with the majority population. This systems-based framework integrates evidence from both expert opinion and published literature, to map the factors influencing dietary and physical activity behaviours in ethnic minority groups. Our findings illustrate that innovative research and complex interventions need to be developed that are sensitive to the needs of ethnic minority populations. A systems approach that encompasses the complexity of the inter-related factors that drive behaviours may inform a more holistic public health paradigm to more effectively reach ethnic minorities living in Europe, as well as the majority host population.

Mujeres Fuertes y Corazones Saludables: adaptation of the StrongWomen -healthy hearts program for rural Latinas using an intervention mapping approach.

PubMed

Perry, Cynthia K; McCalmont, Jean C; Ward, Judy P; Menelas, Hannah-Dulya K; Jackson, Christie; De Witz, Jazmyne R; Solanki, Emma; Seguin, Rebecca A

2017-12-28

To describe our use of intervention mapping as a systematic method to adapt an evidence-based physical activity and nutrition program to reflect the needs of rural Latinas. An intervention mapping process involving six steps guided the adaptation of an evidence based physical activity and nutrition program, using a community-based participatory research approach. We partnered with a community advisory board of rural Latinas throughout the adaptation process. A needs assessment and logic models were used to ascertain which program was the best fit for adaptation. Once identified, we collaborated with one of the developers of the original program (StrongWomen - Healthy Hearts) during the adaptation process. First, essential theoretical methods and program elements were identified, and additional elements were added or adapted. Next, we reviewed and made changes to reflect the community and cultural context of the practical applications, intervention strategies, program curriculum, materials, and participant information. Finally, we planned for the implementation and evaluation of the adapted program, Mujeres Fuertes y Corazones Saludables, within the context of the rural community. A pilot study will be conducted with overweight, sedentary, middle-aged, Spanish-speaking Latinas. Outcome measures will assess change in weight, physical fitness, physical activity, and nutrition behavior. The intervention mapping process was feasible and provided a systematic approach to balance fit and fidelity in the adaptation of an evidence-based program. Collaboration with community members ensured that the components of the curriculum that were adapted were culturally appropriate and relevant within the local community context.

Mapping-guided characterization of mechanical and electrical activation patterns in patients with normal systolic function using a sensor-based tracking technology.

PubMed

Piorkowski, Christopher; Breithardt, Ole-A; Razavi, Hedi; Nabutovsky, Yelena; Rosenberg, Stuart P; Markovitz, Craig D; Arya, Arash; Rolf, Sascha; John, Silke; Kosiuk, Jedrzej; Olson, Eric; Eitel, Charlotte; Huo, Yan; Döring, Michael; Richter, Sergio; Ryu, Kyungmoo; Gaspar, Thomas; Prinzen, Frits W; Hindricks, Gerhard; Sommer, Philipp

2017-10-01

In times of evolving cardiac resynchronization therapy, intra-procedural characterization of left ventricular (LV) mechanical activation patterns is desired but technically challenging with currently available technologies. In patients with normal systolic function, we evaluated the feasibility of characterizing LV wall motion using a novel sensor-based, real-time tracking technology. Ten patients underwent simultaneous motion and electrical mapping of the LV endocardium during sinus rhythm using electroanatomical mapping and navigational systems (EnSite™ NavX™ and MediGuide™, SJM). Epicardial motion data were also collected simultaneously at corresponding locations from accessible coronary sinus branches. Displacements at each mapping point and times of electrical and mechanical activation were combined over each of the six standard LV wall segments. Mechanical activation timing was compared with that from electrical activation and preoperative 2D speckle tracking echocardiography (echo). MediGuide-based displacement data were further analysed to estimate LV chamber volumes that were compared with echo and magnetic resonance imaging (MRI). The lateral and septal walls exhibited the largest (12.5 [11.6-15.0] mm) and smallest (10.2 [9.0-11.3] mm) displacement, respectively. Radial displacement was significantly larger endocardially than epicardially (endo: 6.7 [5.0-9.1] mm; epi: 3.8 [2.4-5.6] mm), while longitudinal displacement was significantly larger epicardially (endo: 8.0 [5.0-10.6] mm; epi: 10.3 [7.4-13.8] mm). Most often, the anteroseptal/anterior and lateral walls showed the earliest and latest mechanical activations, respectively. 9/10 patients had concordant or adjacent wall segments of latest mechanical and electrical activation, and 6/10 patients had concordant or adjacent wall segments of latest mechanical activation as measured by MediGuide and echo. MediGuide's LV chamber volumes were significantly correlated with MRI (R2= 0.73, P < 0.01) and echo (R2= 0.75, P < 0.001). The feasibility of mapping-guided intra-procedural characterization of LV wall motion was established. http://www.clinicaltrials.gov; Unique identifier: CT01629160. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

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.

Curriculum Mapping in Higher Education: A Case Study and Proposed Content Scope and Sequence Mapping Tool

ERIC Educational Resources Information Center

Arafeh, Sousan

2016-01-01

Best practice in curriculum development and implementation requires that discipline-based standards or requirements embody both curricular and programme scopes and sequences. Ensuring these are present and aligned in course/programme content, activities and assessments to support student success requires formalised and systematised review and…

A gene-derived SNP-based high resolution linkage map of carrot including the location of QTL conditioning root and leaf anthocyanin pigmentation

USDA-ARS?s Scientific Manuscript database

Background: Purple carrots accumulate large quantities of anthocyanins in their roots and leaves. These flavonoid pigments possess antioxidant activity and are implicated in providing health benefits. The lack of informative and saturated linkage maps associated with well characterized populations s...

I Move: systematic development of a web-based computer tailored physical activity intervention, based on motivational interviewing and self-determination theory

PubMed Central

2014-01-01

Background This article describes the systematic development of the I Move intervention: a web-based computer tailored physical activity promotion intervention, aimed at increasing and maintaining physical activity among adults. This intervention is based on the theoretical insights and practical applications of self-determination theory and motivational interviewing. Methods/design Since developing interventions in a systemically planned way increases the likelihood of effectiveness, we used the Intervention Mapping protocol to develop the I Move intervention. In this article, we first describe how we proceeded through each of the six steps of the Intervention Mapping protocol. After that, we describe the content of the I Move intervention and elaborate on the planned randomized controlled trial. Discussion By integrating self-determination theory and motivational interviewing in web-based computer tailoring, the I Move intervention introduces a more participant-centered approach than traditional tailored interventions. Adopting this approach might enhance computer tailored physical activity interventions both in terms of intervention effectiveness and user appreciation. We will evaluate this in an randomized controlled trial, by comparing the I Move intervention to a more traditional web-based computer tailored intervention. Trial registration NTR4129 PMID:24580802

Toward an operational framework for fine-scale urban land-cover mapping in Wallonia using submeter remote sensing and ancillary vector data

NASA Astrophysics Data System (ADS)

Beaumont, Benjamin; Grippa, Tais; Lennert, Moritz; Vanhuysse, Sabine; Stephenne, Nathalie; Wolff, Eléonore

2017-07-01

Encouraged by the EU INSPIRE directive requirements and recommendations, the Walloon authorities, similar to other EU regional or national authorities, want to develop operational land-cover (LC) and land-use (LU) mapping methods using existing geodata. Urban planners and environmental monitoring stakeholders of Wallonia have to rely on outdated, mixed, and incomplete LC and LU information. The current reference map is 10-years old. The two object-based classification methods, i.e., a rule- and a classifier-based method, for detailed regional urban LC mapping are compared. The added value of using the different existing geospatial datasets in the process is assessed. This includes the comparison between satellite and aerial optical data in terms of mapping accuracies, visual quality of the map, costs, processing, data availability, and property rights. The combination of spectral, tridimensional, and vector data provides accuracy values close to 0.90 for mapping the LC into nine categories with a minimum mapping unit of 15 m2. Such a detailed LC map offers opportunities for fine-scale environmental and spatial planning activities. Still, the regional application poses challenges regarding automation, big data handling, and processing time, which are discussed.

Using GeoMapApp in the Classroom

NASA Astrophysics Data System (ADS)

Goodwillie, A. M.

2017-12-01

The GeoMapApp tool has been updated with enhanced functionality that is useful in the classroom. Hosted as a service of the IEDA Facility at Columbia University, GeoMapApp (http://www.geomapapp.org) is a free resource that integrates a wide range of research-grade geoscience data in one intuitive map-based interface. It includes earthquake and volcano data, geological maps, plate tectonic data sets, and a high-resolution topography/bathymetry base map. Users can also import and analyse their own data files. Layering and transparency capabilities allow users to compare multiple data sets at once. The GeoMapApp interface presents data in its proper geospatial context, helping students more easily gain insight and understanding from the data. Simple tools for data manipulation allow students to analyse the data in different ways such as generating profiles and producing visualisations for reports. The new Save Session capability is designed to assist in the classroom: The educator saves a pre-loaded state of GeoMapApp. When shared with the class, the saved session file allows students to open GeoMapApp with exactly the same data sets loaded and the same display parameters chosen thus freeing up valuable time in which students can explore the data. In this presentation, activities related to plate tectonics will be highlighted. One activity helps students investigate plate boundaries by exploring earthquake and volcano locations. Another requires students to calculate the rate of seafloor spreading using crustal age data in various ocean basins. A third uses the GeoMapApp layering technique to explore the influence of geological forces in shaping the landscape. Educators report that using GeoMapApp in the classroom lowers the barriers to data accessibility for students; fosters an increased sense of data "ownership" - GeoMapApp presents the same data in the same tool used by researchers; allows engagement with authentic geoscience data; promotes STEM skills and exposure.

Human Activity Modeling and Simulation with High Biofidelity

DTIC Science & Technology

2013-01-01

Human activity Modeling and Simulation (M&S) plays an important role in simulation-based training and Virtual Reality (VR). However, human activity M...kinematics and motion mapping/creation; and (e) creation and replication of human activity in 3-D space with true shape and motion. A brief review is

Procedures for woody vegetation surveys in the Kazgail rural council area, Kordofan, Sudan

USGS Publications Warehouse

Falconer, Allan; Cross, Matthew D.; Orr, Donald G.

1990-01-01

Efforts to reforest parts of the Kordofan Province of Sudan are receiving support from international development agencies. These efforts include planning and implementing reforestation activities that require the collection of natural resources and socioeconomic data, and the preparation of base maps. A combination of remote sensing, geographic information system and global positioning systems procedures are used in this study to meet these requirements.Remote sensing techniques were used to provide base maps and to guide the compilation of vegetation resources maps. These techniques provided a rapid and efficient method for documenting available resources. Pocket‐sized global positioning system units were used to establish the location of field data collected for mapping and resource analysis. A microcomputer data management system tabulated and displayed the field data. The resulting system for data analysis, management, and planning has been adopted for the mapping and inventory of the Gum Belt of Sudan.

First Map of Residential Indoor Radon Measurements in Azerbaijan.

PubMed

Hoffmann, M; Aliyev, C S; Feyzullayev, A A; Baghirli, R J; Veliyeva, F F; Pampuri, L; Valsangiacomo, C; Tollefsen, T; Cinelli, G

2017-06-15

This article describes results of the first measurements of indoor radon concentrations in Azerbaijan, including description of the methodology and the mathematical and statistical processing of the results obtained. Measured radon concentrations varied considerably: from almost radon-free houses to around 1100 Bq m-3. However, only ~7% of the total number of measurements exceeded the maximum permissible concentrations. Based on these data, maps of the distribution of volumetric activity and elevated indoor radon concentrations in Azerbaijan were created. These maps reflect a mosaic character of distribution of radon and enhanced values that are confined to seismically active areas at the intersection of an active West Caspian fault with sub-latitudinal faults along the Great and Lesser Caucasus and the Talysh mountains. Spatial correlation of radon and temperature behavior is also described. The data gathered on residential indoor radon have been integrated into the European Indoor Radon Map. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The Barley Magnesium Chelatase 150-kD Subunit Is Not an Abscisic Acid Receptor1[OA

PubMed Central

Müller, André H.; Hansson, Mats

2009-01-01

Magnesium chelatase is the first unique enzyme of the chlorophyll biosynthetic pathway. It is composed of three gene products of which the largest is 150 kD. This protein was recently identified as an abscisic acid receptor in Arabidopsis (Arabidopsis thaliana). We have evaluated whether the barley (Hordeum vulgare) magnesium chelatase large subunit, XanF, could be a receptor for the phytohormone. The study involved analysis of recombinant magnesium chelatase protein as well as several induced chlorophyll-deficient magnesium chelatase mutants with defects identified at the gene and protein levels. Abscisic acid had no effect on magnesium chelatase activity and binding to the barley 150-kD protein could not be shown. Magnesium chelatase mutants showed a wild-type response in respect to postgermination growth and stomatal aperture. Our results question the function of the large magnesium chelatase subunit as an abscisic acid receptor. PMID:19176716

Synthesis, structural characterization and effect on human granulocyte intracellular cAMP levels of abscisic acid analogs.

PubMed

Bellotti, Marta; Salis, Annalisa; Grozio, Alessia; Damonte, Gianluca; Vigliarolo, Tiziana; Galatini, Andrea; Zocchi, Elena; Benatti, Umberto; Millo, Enrico

2015-01-01

The phytohormone abscisic acid (ABA), in addition to regulating physiological functions in plants, is also produced and released by several mammalian cell types, including human granulocytes, where it stimulates innate immune functions via an increase of the intracellular cAMP concentration ([cAMP]i). We synthesized several ABA analogs and evaluated the structure-activity relationship, by the systematical modification of selected regions of these analogs. The resulting molecules were tested for their ability to inhibit the ABA-induced increase of [cAMP]i in human granulocytes. The analogs with modified configurations at C-2' and C-3' abrogated the ABA-induced increase of the [cAMP]i and also inhibited several pro-inflammatory effects induced by exogenous ABA on granulocytes and monocytes. Accordingly, these analogs could be suitable as novel putative anti-inflammatory compounds. Copyright © 2014 Elsevier Ltd. All rights reserved.

Modulation of IAA production in cyanobacteria by tryptophan and light.

PubMed

Prasanna, Radha; Joshi, Monica; Rana, Anuj; Nain, Lata

2010-01-01

Cyanobacteria represent less a investigated group of prokaryote, in terms of their plant growth promoting potential, especially in relation to the production of phytohormones. The present investigation was aimed towards analyzing growth kinetics, indole acetic acid (IAA) production and acetylene reduction activity (ARA) as an index of nitrogen fixation in two selected cyanobacterial strains belonging to the genus Anabaena, as influenced by tryptophan supplementation and light:dark conditions. Interesting observations were recorded in terms of enhancement of IAA production accompanied by protein and chlorophyll accumulation in the two cyanobacterial strains grown in media without tryptophan and incubated under light:dark or continuous light conditions. Colorimetric and chromatographic analyses supported the observations that tryptophan is not essential as a precursor for IAA biosynthesis in these cyanobacteria. Further study is in progress to identify genes involved in the tryptophan independent pathway for IAA biosynthesis.

Light as stress factor to plant roots – case of root halotropism

PubMed Central

Yokawa, Ken; Fasano, Rossella; Kagenishi, Tomoko; Baluška, František

2014-01-01

Despite growing underground, largely in darkness, roots emerge to be very sensitive to light. Recently, several important papers have been published which reveal that plant roots not only express all known light receptors but also that their growth, physiology and adaptive stress responses are light-sensitive. In Arabidopsis, illumination of roots speeds-up root growth via reactive oxygen species-mediated and F-actin dependent process. On the other hand, keeping Arabidopsis roots in darkness alters F-actin distribution, polar localization of PIN proteins as well as polar transport of auxin. Several signaling components activated by phytohormones are overlapping with light-related signaling cascade. We demonstrated that the sensitivity of roots to salinity is altered in the light-grown Arabidopsis roots. Particularly, light-exposed roots are less effective in their salt-avoidance behavior known as root halotropism. Here we discuss these new aspects of light-mediated root behavior from cellular, physiological and evolutionary perspectives. PMID:25566292

Behind the lines–actions of bacterial type III effector proteins in plant cells

PubMed Central

Büttner, Daniela

2016-01-01

Pathogenicity of most Gram-negative plant-pathogenic bacteria depends on the type III secretion (T3S) system, which translocates bacterial effector proteins into plant cells. Type III effectors modulate plant cellular pathways to the benefit of the pathogen and promote bacterial multiplication. One major virulence function of type III effectors is the suppression of plant innate immunity, which is triggered upon recognition of pathogen-derived molecular patterns by plant receptor proteins. Type III effectors also interfere with additional plant cellular processes including proteasome-dependent protein degradation, phytohormone signaling, the formation of the cytoskeleton, vesicle transport and gene expression. This review summarizes our current knowledge on the molecular functions of type III effector proteins with known plant target molecules. Furthermore, plant defense strategies for the detection of effector protein activities or effector-triggered alterations in plant targets are discussed. PMID:28201715

Gibberellin Receptor GID1: Gibberellin Recognition and Molecular Evolution

NASA Astrophysics Data System (ADS)

Kato, Hiroaki; Sato, Tomomi; Ueguchi-Tanaka, Miyako

Gibberellins (GAs) are phytohormones essential for many developmental processes in plants. We analyzed the crystal structure of a nuclear GA receptor, GIBBERELLIN INSENSITIVE DWARF 1 (GID1) from Oryza sativa. As it was proposed from the sequence similarity, the overall structure of GID1 shows an α/β-hydrolase fold similar to that of the hormone-sensitive lipases (HSLs) except for an amino-terminal lid. The GA-binding site corresponds to the substrate-binding site of HSLs. Almost residues assigned for GA binding showed very little or no activity when they were replaced with Ala. The substitution of the residues corresponding to those of the lycophyte GID1s caused an increase in the binding affinity for GA34, a 2β-hydroxylated GA4. These findings indicate that GID1 originated from HSL and was tinkered to have the specificity for bioactive GAs in the course of plant evolution.

Surveillance for Neisseria meningitidis Disease Activity and Transmission Using Information Technology

PubMed Central

Ahmed, S. Sohail; Oviedo-Orta, Ernesto; Mekaru, Sumiko R.; Freifeld, Clark C.; Tougas, Gervais; Brownstein, John S.

2015-01-01

Background While formal reporting, surveillance, and response structures remain essential to protecting public health, a new generation of freely accessible, online, and real-time informatics tools for disease tracking are expanding the ability to raise earlier public awareness of emerging disease threats. The rationale for this study is to test the hypothesis that the HealthMap informatics tools can complement epidemiological data captured by traditional surveillance monitoring systems for meningitis due to Neisseria meningitides (N. meningitides) by highlighting severe transmissible disease activity and outbreaks in the United States. Methods Annual analyses of N. meningitides disease alerts captured by HealthMap were compared to epidemiological data captured by the Centers for Disease Control’s Active Bacterial Core surveillance (ABCs) for N. meningitides. Morbidity and mortality case reports were measured annually from 2010 to 2013 (HealthMap) and 2005 to 2012 (ABCs). Findings HealthMap N. meningitides monitoring captured 80-90% of alerts as diagnosed N. meningitides, 5-20% of alerts as suspected cases, and 5-10% of alerts as related news articles. HealthMap disease alert activity for emerging disease threats related to N. meningitides were in agreement with patterns identified historically using traditional surveillance systems. HealthMap’s strength lies in its ability to provide a cumulative “snapshot” of weak signals that allows for rapid dissemination of knowledge and earlier public awareness of potential outbreak status while formal testing and confirmation for specific serotypes is ongoing by public health authorities. Conclusions The underreporting of disease cases in internet-based data streaming makes inadequate any comparison to epidemiological trends illustrated by the more comprehensive ABCs network published by the Centers for Disease Control. However, the expected delays in compiling confirmatory reports by traditional surveillance systems (at the time of writing, ABCs data for 2013 is listed as being provisional) emphasize the helpfulness of real-time internet-based data streaming to quickly fill gaps including the visualization of modes of disease transmission in outbreaks for better resource and action planning. HealthMap can also contribute as an internet-based monitoring system to provide real-time channel for patients to report intervention-related failures. PMID:25992552

SCFTIR1/AFB-auxin signalling regulates PIN vacuolar trafficking and auxin fluxes during root gravitropism

PubMed Central

Baster, Paweł; Robert, Stéphanie; Kleine-Vehn, Jürgen; Vanneste, Steffen; Kania, Urszula; Grunewald, Wim; De Rybel, Bert; Beeckman, Tom; Friml, Jiří

2013-01-01

The distribution of the phytohormone auxin regulates many aspects of plant development including growth response to gravity. Gravitropic root curvature involves coordinated and asymmetric cell elongation between the lower and upper side of the root, mediated by differential cellular auxin levels. The asymmetry in the auxin distribution is established and maintained by a spatio-temporal regulation of the PIN-FORMED (PIN) auxin transporter activity. We provide novel insights into the complex regulation of PIN abundance and activity during root gravitropism. We show that PIN2 turnover is differentially regulated on the upper and lower side of gravistimulated roots by distinct but partially overlapping auxin feedback mechanisms. In addition to regulating transcription and clathrin-mediated internalization, auxin also controls PIN abundance at the plasma membrane by promoting their vacuolar targeting and degradation. This effect of elevated auxin levels requires the activity of SKP-Cullin-F-boxTIR1/AFB (SCFTIR1/AFB)-dependent pathway. Importantly, also suboptimal auxin levels mediate PIN degradation utilizing the same signalling pathway. These feedback mechanisms are functionally important during gravitropic response and ensure fine-tuning of auxin fluxes for maintaining as well as terminating asymmetric growth. PMID:23211744

Plasma membrane H+-ATPase regulation is required for auxin gradient formation preceding phototropic growth

PubMed Central

Hohm, Tim; Demarsy, Emilie; Quan, Clément; Allenbach Petrolati, Laure; Preuten, Tobias; Vernoux, Teva; Bergmann, Sven; Fankhauser, Christian

2014-01-01

Phototropism is a growth response allowing plants to align their photosynthetic organs toward incoming light and thereby to optimize photosynthetic activity. Formation of a lateral gradient of the phytohormone auxin is a key step to trigger asymmetric growth of the shoot leading to phototropic reorientation. To identify important regulators of auxin gradient formation, we developed an auxin flux model that enabled us to test in silico the impact of different morphological and biophysical parameters on gradient formation, including the contribution of the extracellular space (cell wall) or apoplast. Our model indicates that cell size, cell distributions, and apoplast thickness are all important factors affecting gradient formation. Among all tested variables, regulation of apoplastic pH was the most important to enable the formation of a lateral auxin gradient. To test this prediction, we interfered with the activity of plasma membrane H+-ATPases that are required to control apoplastic pH. Our results show that H+-ATPases are indeed important for the establishment of a lateral auxin gradient and phototropism. Moreover, we show that during phototropism, H+-ATPase activity is regulated by the phototropin photoreceptors, providing a mechanism by which light influences apoplastic pH. PMID:25261457

SCF(TIR1/AFB)-auxin signalling regulates PIN vacuolar trafficking and auxin fluxes during root gravitropism.

PubMed

Baster, Paweł; Robert, Stéphanie; Kleine-Vehn, Jürgen; Vanneste, Steffen; Kania, Urszula; Grunewald, Wim; De Rybel, Bert; Beeckman, Tom; Friml, Jiří

2013-01-23

The distribution of the phytohormone auxin regulates many aspects of plant development including growth response to gravity. Gravitropic root curvature involves coordinated and asymmetric cell elongation between the lower and upper side of the root, mediated by differential cellular auxin levels. The asymmetry in the auxin distribution is established and maintained by a spatio-temporal regulation of the PIN-FORMED (PIN) auxin transporter activity. We provide novel insights into the complex regulation of PIN abundance and activity during root gravitropism. We show that PIN2 turnover is differentially regulated on the upper and lower side of gravistimulated roots by distinct but partially overlapping auxin feedback mechanisms. In addition to regulating transcription and clathrin-mediated internalization, auxin also controls PIN abundance at the plasma membrane by promoting their vacuolar targeting and degradation. This effect of elevated auxin levels requires the activity of SKP-Cullin-F-box(TIR1/AFB) (SCF(TIR1/AFB))-dependent pathway. Importantly, also suboptimal auxin levels mediate PIN degradation utilizing the same signalling pathway. These feedback mechanisms are functionally important during gravitropic response and ensure fine-tuning of auxin fluxes for maintaining as well as terminating asymmetric growth.

Involvement of WRKY Transcription Factors in Abscisic-Acid-Induced Cold Tolerance of Banana Fruit.

PubMed

Luo, Dong-Lan; Ba, Liang-Jie; Shan, Wei; Kuang, Jian-Fei; Lu, Wang-Jin; Chen, Jian-Ye

2017-05-10

Phytohormone abscisic acid (ABA) and plant-specific WRKY transcription factors (TFs) have been implicated to play important roles in various stress responses. The involvement of WRKY TFs in ABA-mediated cold tolerance of economical fruits, such as banana fruit, however remains largely unknown. Here, we reported that ABA application could induce expressions of ABA biosynthesis-related genes MaNCED1 and MaNCED2, increase endogenous ABA contents, and thereby enhance cold tolerance in banana fruit. Four banana fruit WRKY TFs, designated as MaWRKY31, MaWRKY33, MaWRKY60, and MaWRKY71, were identified and characterized. All four of these MaWRKYs were nuclear-localized and displayed transactivation activities. Their expressions were induced by ABA treatment during cold storage. More importantly, the gel mobility shift assay and transient expression analysis revealed that MaWRKY31, MaWRKY33, MaWRKY60, and MaWRKY71 directly bound to the W-box elements in MaNCED1 and MaNCED2 promoters and activated their expressions. Taken together, our findings demonstrate that banana fruit WRKY TFs are involved in ABA-induced cold tolerance by, at least in part, increasing ABA levels via directly activating NECD expressions.

Cyclophilin 20-3 is positioned as a regulatory hub between light-dependent redox and 12-oxo-phytodienoic acid signaling.

PubMed

Cheong, Hoon; Barbosa Dos Santos, Izailda; Liu, Wenshan; Gosse, Heather N; Park, Sang-Wook

2017-09-02

The jasmonate family of phytohormones plays central roles in plant development and stress acclimation. However, the regulatory modes of their signaling circuitry remain largely unknown. Here we describe that cyclophilin 20-3 (CYP20-3), a binding protein of (+)-12-oxo-phytodienoic acid (OPDA), crisscrosses stress responses with light-dependent redox reactions, which fine-tunes the activity of key enzymes in the plastid photosynthetic carbon assimilation and sulfur assimilation pathways. Under stressed states, OPDA - accumulated in the chloroplasts - binds and promotes CYP20-3 to transfer electron (e - ) from thioredoxins (i.e., type-f2 and -x) to 2-Cys peroxiredoxin B (2-CysPrxB) or serine acetyltransferase 1 (SAT1). Reduction (activation) of 2-CysPrxB then optimizes peroxide detoxification and carbon metabolisms in the photosynthesis, whereas the activation of SAT1 stimulates sulfur assimilation which in turn coordinates redox-resolved nucleus gene expressions in defense responses against biotic and abiotic stresses. Thus, we conclude that CYP20-3 is positioned as a unique metabolic hub in the interface between photosynthesis (light) and OPDA signaling, where controls resource (e - ) allocations between plant growth and defense responses.

Hydrologic unit maps

USGS Publications Warehouse

Seaber, Paul R.; Kapinos, F. Paul; Knapp, George L.

1987-01-01

A set of maps depicting approved boundaries of, and numerical codes for, river-basin units of the United States has been developed by the U.S . Geological Survey. These 'Hydrologic Unit Maps' are four-color maps that present information on drainage, culture, hydrography, and hydrologic boundaries and codes of (1) the 21 major water-resources regions and the 222 subregions designated by the U.S . Water Resources Council, (2) the 352 accounting units of the U.S. Geological Survey's National Water Data Network, and (3) the 2,149 cataloging units of the U.S . Geological Survey's 'Catalog of information on Water Data:' The maps are plotted on the Geological Survey State base-map series at a scale of 1 :500,000 and, except for Alaska, depict hydrologic unit boundaries for all drainage basins greater than 700 square miles (1,813 square kilometers). A complete list of all the hydrologic units, along with their drainage areas, their names, and the names of the States or outlying areas in which they reside, is contained in the report. These maps and associated codes provide a standardized base for use by water-resources organizations in locating, storing, retrieving, and exchanging hydrologic data, in indexing and inventorying hydrologic data and information, in cataloging water-data acquisition activities, and in a variety of other applications. Because the maps have undergone extensive review by all principal Federal, regional, and State water-resource agencies, they are widely accepted for use in planning and describing water-use and related land-use activities, and in geographically organizing hydrologic data . Examples of these uses are given in the report . The hydrologic unit codes shown on the maps have been approved as a Federal Information Processing Standard for use by the Federal establishment.

Lean manufacturing analysis to reduce waste on production process of fan products

NASA Astrophysics Data System (ADS)

Siregar, I.; Nasution, A. A.; Andayani, U.; Sari, R. M.; Syahputri, K.; Anizar

2018-02-01

This research is based on case study that being on electrical company. One of the products that will be researched is the fan, which when running the production process there is a time that is not value-added, among others, the removal of material which is not efficient in the raw materials and component molding fan. This study aims to reduce waste or non-value added activities and shorten the total lead time by using the tools Value Stream Mapping. Lean manufacturing methods used to analyze and reduce the non-value added activities, namely the value stream mapping analysis tools, process mapping activity with 5W1H, and tools 5 whys. Based on the research note that no value-added activities in the production process of a fan of 647.94 minutes of total lead time of 725.68 minutes. Process cycle efficiency in the production process indicates that the fan is still very low at 11%. While estimates of the repair showed a decrease in total lead time became 340.9 minutes and the process cycle efficiency is greater by 24%, which indicates that the production process has been better.

A Mindtool-Based Collaborative Learning Approach to Enhancing Students' Innovative Performance in Management Courses

ERIC Educational Resources Information Center

Wu, Chih-Hsiang; Hwang, Gwo-Jen; Kuo, Fan-Ray; Huang, Iwen

2013-01-01

Educators have indicated that creative teaching is the most important educational activity; nevertheless, most existing education systems fail to engage students in effective creative tasks. To address this issue, this study proposes a mind map based collaborative learning approach for supporting creative learning activities and enhancing…

EnviroAtlas - Austin, TX - Demographics by Block Group Web Service

EPA Pesticide Factsheets

This EnviroAtlas web service supports research and online mapping activities related to EnviroAtlas (https://enviroatlas.epa.gov/EnviroAtlas). This EnviroAtlas dataset is a summary of key demographic groups for the EnviroAtlas community. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

Project Mapping to Build Capacity and Demonstrate Impact in the Earth Sciences

NASA Astrophysics Data System (ADS)

Hemmings, S. N.; Searby, N. D.; Murphy, K. J.; Mataya, C. J.; Crepps, G.; Clayton, A.; Stevens, C. L.

2017-12-01

Diverse organizations are increasingly using project mapping to communicate location-based information about their activities. NASA's Earth Science Division (ESD), through the Earth Science Data Systems and Applied Sciences' Capacity Building Program (CBP), has created a geographic information system of all ESD projects to support internal program management for the agency. The CBP's NASA DEVELOP program has built an interactive mapping tool to support capacity building for the program's varied constituents. This presentation will explore the types of programmatic opportunities provided by a geographic approach to management, communication, and strategic planning. We will also discuss the various external benefits that mapping supports and that build capacity in the Earth sciences. These include activities such as project matching (location-focused synergies), portfolio planning, inter- and intra-organizational collaboration, science diplomacy, and basic impact analysis.

Whole-brain functional magnetic resonance imaging mapping of acute nociceptive responses induced by formalin in rats using atlas registration-based event-related analysis.

PubMed

Shih, Yen-Yu I; Chen, You-Yin; Chen, Chiao-Chi V; Chen, Jyh-Cheng; Chang, Chen; Jaw, Fu-Shan

2008-06-01

Nociceptive neuronal activation in subcortical regions has not been well investigated in functional magnetic resonance imaging (fMRI) studies. The present report aimed to use the blood oxygenation level-dependent (BOLD) fMRI technique to map nociceptive responses in both subcortical and cortical regions by employing a refined data processing method, the atlas registration-based event-related (ARBER) analysis technique. During fMRI acquisition, 5% formalin (50 mul) was injected into the left hindpaw to induce nociception. ARBER was then used to normalize the data among rats, and images were analyzed using automatic selection of the atlas-based region of interest. It was found that formalin-induced nociceptive processing increased BOLD signals in both cortical and subcortical regions. The cortical activation was distributed over the cingulate, motor, somatosensory, insular, and visual cortices, and the subcortical activation involved the caudate putamen, hippocampus, periaqueductal gray, superior colliculus, thalamus, and hypothalamus. With the aid of ARBER, the present study revealed a detailed activation pattern that possibly indicated the recruitment of various parts of the nociceptive system. The results also demonstrated the utilization of ARBER in establishing an fMRI-based whole-brain nociceptive map. The formalin induced nociceptive images may serve as a template of central nociceptive responses, which can facilitate the future use of fMRI in evaluation of new drugs and preclinical therapies for pain. (c) 2008 Wiley-Liss, Inc.

MAP as a model for practice-based learning and improvement in child psychiatry training.

PubMed

Kataoka, Sheryl H; Podell, Jennifer L; Zima, Bonnie T; Best, Karin; Sidhu, Shawn; Jura, Martha Bates

2014-01-01

Not only is there a growing literature demonstrating the positive outcomes that result from implementing evidence based treatments (EBTs) but also studies that suggest a lack of delivery of these EBTs in "usual care" practices. One way to address this deficit is to improve the quality of psychotherapy teaching for clinicians-in-training. The Accreditation Council for Graduate Medical Education (ACGME) requires all training programs to assess residents in a number of competencies including Practice-Based Learning and Improvements (PBLI). This article describes the piloting of Managing and Adapting Practice (MAP) for child psychiatry fellows, to teach them both EBT and PBLI skills. Eight child psychiatry trainees received 5 full days of MAP training and are delivering MAP in a year-long outpatient teaching clinic. In this setting, MAP is applied to the complex, multiply diagnosed psychiatric patients that present to this clinic. This article describes how MAP tools and resources assist in teaching trainees each of the eight required competency components of PBLI, including identifying deficits in expertise, setting learning goals, performing learning activities, conducting quality improvement methods in practice, incorporating formative feedback, using scientific studies to inform practice, using technology for learning, and participating in patient education. A case example illustrates the use of MAP in teaching PBLI. MAP provides a unique way to teach important quality improvement and practice-based learning skills to trainees while training them in important psychotherapy competence.

Can Mapping Algorithms Based on Raw Scores Overestimate QALYs Gained by Treatment? A Comparison of Mappings Between the Roland-Morris Disability Questionnaire and the EQ-5D-3L Based on Raw and Differenced Score Data.

PubMed

Madan, Jason; Khan, Kamran A; Petrou, Stavros; Lamb, Sarah E

2017-05-01

Mapping algorithms are increasingly being used to predict health-utility values based on responses or scores from non-preference-based measures, thereby informing economic evaluations. We explored whether predictions in the EuroQol 5-dimension 3-level instrument (EQ-5D-3L) health-utility gains from mapping algorithms might differ if estimated using differenced versus raw scores, using the Roland-Morris Disability Questionnaire (RMQ), a widely used health status measure for low back pain, as an example. We estimated algorithms mapping within-person changes in RMQ scores to changes in EQ-5D-3L health utilities using data from two clinical trials with repeated observations. We also used logistic regression models to estimate response mapping algorithms from these data to predict within-person changes in responses to each EQ-5D-3L dimension from changes in RMQ scores. Predicted health-utility gains from these mappings were compared with predictions based on raw RMQ data. Using differenced scores reduced the predicted health-utility gain from a unit decrease in RMQ score from 0.037 (standard error [SE] 0.001) to 0.020 (SE 0.002). Analysis of response mapping data suggests that the use of differenced data reduces the predicted impact of reducing RMQ scores across EQ-5D-3L dimensions and that patients can experience health-utility gains on the EQ-5D-3L 'usual activity' dimension independent from improvements captured by the RMQ. Mappings based on raw RMQ data overestimate the EQ-5D-3L health utility gains from interventions that reduce RMQ scores. Where possible, mapping algorithms should reflect within-person changes in health outcome and be estimated from datasets containing repeated observations if they are to be used to estimate incremental health-utility gains.

Temperature Regulation of Endogenous Gibberellin Activity and Development of Tulipa gesneriana L. 1

PubMed Central

Aung, L. H.; De Hertogh, A. A.; Staby, G.

1969-01-01

The changes in the contents of free and bound gibberellin-like activity (GA) of Tulipa gesneriana L. cv. Ralph during development under 2 temperature conditions were studied. The results show that the content of free GA of bulbs grown at 18° increased by 67% over the initial level during development. The bound GA showed a slight initial increase and was followed by a rapid decrease. In contrast, bulbs treated at 13° showed a marked decline in free GA and a 2-fold increase in the content of bound GA. However, after the transfer of these bulbs from 13° to 18° the free GA increased to the initial level while the bound GA decreased to a low level. The rate of floral shoot and root development and time of flowering were accelerated at 18° as compared to 13°. From the data obtained, it was suggested that a temperature-sensitive interconversion mechanism between free and bound GA exists in tulip bulbs and that there is apparent synthesis or transformation of these phytohormones during development of the bulbs. PMID:16657075

Activation of YUCCA5 by the Transcription Factor TCP4 Integrates Developmental and Environmental Signals to Promote Hypocotyl Elongation in Arabidopsis.

PubMed

Challa, Krishna Reddy; Aggarwal, Pooja; Nath, Utpal

2016-09-05

Cell expansion is an essential process in plant morphogenesis and is regulated by the coordinated action of environmental stimuli and endogenous factors, such as the phytohormones auxin and brassinosteroid. Although the biosynthetic pathways that generate these hormones and their downstream signaling mechanisms have been extensively studied, the upstream transcriptional network that modulates their levels and connects their action to cell morphogenesis is less clear. Here we show that the miR319-regulated TCP (TEOSINTE BRANCHED 1, CYCLODEA, PROLIFERATING CELL FACTORS) transcription factors, notably TCP4, directly activate YUCCA5 transcription and integrate the auxin response to a brassinosteroid-dependent molecular circuit that promotes cell elongation in Arabidopsis hypocotyls. Further, TCP4 modulates the common transcriptional network downstream to auxin-BR signaling, which is also triggered by environmental cues, such as light, to promote cell expansion. Our study links TCP function with the hormone response during cell morphogenesis and shows that developmental and environmental signals converge on a common transcriptional network to promote cell elongation. {copyright, serif} 2016 American Society of Plant Biologists. All rights reserved.

Prioritizing plant defence over growth through WRKY regulation facilitates infestation by non-target herbivores

PubMed Central

Li, Ran; Zhang, Jin; Li, Jiancai; Zhou, Guoxin; Wang, Qi; Bian, Wenbo; Erb, Matthias; Lou, Yonggen

2015-01-01

Plants generally respond to herbivore attack by increasing resistance and decreasing growth. This prioritization is achieved through the regulation of phytohormonal signaling networks. However, it remains unknown how this prioritization affects resistance against non-target herbivores. In this study, we identify WRKY70 as a specific herbivore-induced, mitogen-activated protein kinase-regulated rice transcription factor that physically interacts with W-box motifs and prioritizes defence over growth by positively regulating jasmonic acid (JA) and negatively regulating gibberellin (GA) biosynthesis upon attack by the chewing herbivore Chilo suppressalis. WRKY70-dependent JA biosynthesis is required for proteinase inhibitor activation and resistance against C. suppressalis. In contrast, WRKY70 induction increases plant susceptibility against the rice brown planthopper Nilaparvata lugens. Experiments with GA-deficient rice lines identify WRKY70-dependent GA signaling as the causal factor in N. lugens susceptibility. Our study shows that prioritizing defence over growth leads to a significant resistance trade-off with important implications for the evolution and agricultural exploitation of plant immunity. DOI: http://dx.doi.org/10.7554/eLife.04805.001 PMID:26083713

J-SHIS - an integrated system for knowing seismic hazard information in Japan

NASA Astrophysics Data System (ADS)

Azuma, H.; Fujiwara, H.; Kawai, S.; Hao, K. X.; Morikawa, N.

2015-12-01

An integrated system of Japan seismic hazard information station (J-SHIS) was established in 2005 for issuing and exchanging information of the National Seismic Hazard Maps for Japan that are based on seismic hazard assessment (SHA). A simplified app, also named J-SHIS, for smartphones is popularly used in Japan based on the integrated system of http://www.j-shis.bosai.go.jp/map/?lang=en. "Smartphone tells hazard" is realized on a cellphone, a tablet and/or a PC. At a given spot, the comprehensive information of SHA map can be easily obtained as below: 1) A SHA probability at given intensity (JMA=5-, 5+, 6-, 6+) within 30 years. 2) A site amplification factor varies within 0.5 ~ 3.0 and expectation is 1 based on surface geology map information. 3) A depth of seismic basement down to ~3,000m based on deeper borehole and geological structure. 4) Scenario earthquake maps: By choosing an active fault, one got the average case for different parameters of the modeling. Then choose a case, you got the shaking map of intensity with color scale. "Seismic Hazard Karte tells more hazard" is another app based on website of http://www.j-shis.bosai.go.jp/labs/karte/. (1) For every mesh of 250m x 250m, professional service SHA information is provided over national-world. (2) With five ranks for eight items, comprehensive SHA information could be delivered. (3) Site amplification factor with an average index is given. (4) Deeper geologic structure modeling is provided with borehole profiling. (5) A SHA probability is assessed within 30 and/or 50 years for the given site. (6) Seismic Hazard curves are given for earthquake sources from inland active fault, subduction zone, undetermined and their summarization. (7) The JMA seismic intensities are assessed in long-term averaged periods of 500-years to ~100,000 years. The app of J-SHIS can be downloaded freely from http://www.j-shis.bosai.go.jp/app-jshis.

Connecting long distance: semantic distance in analogical reasoning modulates frontopolar cortex activity.

PubMed

Green, Adam E; Kraemer, David J M; Fugelsang, Jonathan A; Gray, Jeremy R; Dunbar, Kevin N

2010-01-01

Solving problems often requires seeing new connections between concepts or events that seemed unrelated at first. Innovative solutions of this kind depend on analogical reasoning, a relational reasoning process that involves mapping similarities between concepts. Brain-based evidence has implicated the frontal pole of the brain as important for analogical mapping. Separately, cognitive research has identified semantic distance as a key characteristic of the kind of analogical mapping that can support innovation (i.e., identifying similarities across greater semantic distance reveals connections that support more innovative solutions and models). However, the neural substrates of semantically distant analogical mapping are not well understood. Here, we used functional magnetic resonance imaging (fMRI) to measure brain activity during an analogical reasoning task, in which we parametrically varied the semantic distance between the items in the analogies. Semantic distance was derived quantitatively from latent semantic analysis. Across 23 participants, activity in an a priori region of interest (ROI) in left frontopolar cortex covaried parametrically with increasing semantic distance, even after removing effects of task difficulty. This ROI was centered on a functional peak that we previously associated with analogical mapping. To our knowledge, these data represent a first empirical characterization of how the brain mediates semantically distant analogical mapping.

Significance of phytohormones in Siberian larch-bud gall midge interaction

Treesearch

Rida M. Matrenina

1991-01-01

Interrelations of the bud gall midge and the Siberian larch are of scientific and practical interest because of the bud gall midge's role as a plant endoparasite. We know that attack by the gall midge sets off a reaction in the entire plant. Invasion by the insect results in a certain interaction between physiological mechanisms of the insect and the plant which...

Genome Sequence of Bradyrhizobium japonicum E109, One of the Most Agronomically Used Nitrogen-Fixing Rhizobacteria in Argentina

PubMed Central

Torres, Daniela; Revale, Santiago; Obando, Melissa; Maroniche, Guillermo; Paris, Gastón; Perticari, Alejandro; Vazquez, Martín; Wisniewski-Dyé, Florence; Martínez-Abarca, Francisco

2015-01-01

We present here the complete genome sequence of Bradyrhizobium japonicum strain E109, one of the most used rhizobacteria for soybean inoculation in Argentina since the 1970s. The genome consists of a 9.22-Mbp single chromosome and contains several genes related to nitrogen fixation, phytohormone biosynthesis, and a rhizospheric lifestyle. PMID:25700406

VvMJE1 of the grapevine (Vitis vinifera) VvMES methylesterase family encodes for methyl jasmonate esterase and has a role in stress response

USDA-ARS?s Scientific Manuscript database

The known members of the plant methyl esterase (MES) family catalyze hydrolysis of a C-O ester linkage of methyl esters of several phytohormones including indole-3-acetic acid, salicylic acid, and jasmonic acid. The genome of grapevine (Vitis vinifera) was found to contain 15 MES genes, designated V...

Dancing with Hormones: A Current Perspective of Nitrate Signaling and Regulation in Arabidopsis

PubMed Central

Guan, Peizhu

2017-01-01

In nature and agriculture, nitrate availability is a main environmental cue for plant growth, development and stress responses. Nitrate signaling and regulation are hence at the center of communications between plant intrinsic programs and the environment. It is also well known that endogenous phytohormones play numerous critical roles in integrating extrinsic cues and intrinsic responses, regulating and refining almost all aspects of plant growth, development and stress responses. Therefore, interaction between nitrate and phytohormones, such as auxins, cytokinins, abscisic acid, gibberellins, and ethylene, is prevalent. The growing evidence indicates that biosynthesis, de-conjugation, transport, and signaling of hormones are partly controlled by nitrate signaling. Recent advances with nitrate signaling and transcriptional regulation in Arabidopsis give rise to new paradigms. Given the comprehensive nitrate transport, sensing, signaling and regulations at the level of the cell and organism, nitrate itself is a local and long-distance signal molecule, conveying N status at the whole-plant level. A direct molecular link between nitrate signaling and cell cycle progression was revealed with TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR1-20 (TCP20) – NIN-LIKE PROTEIN 6/7 (NLP6/7) regulatory nexus. NLPs are key regulators of nitrogen responses in plants. TCPs function as the main regulators of plant morphology and architecture, with the emerging role as integrators of plant developmental responses to the environment. By analogy with auxin being proposed as a plant morphogen, nitrate may be an environmental morphogen. The morphogen-gradient-dependent and cell-autonomous mechanisms of nitrate signaling and regulation are an integral part of cell growth and cell identification. This is especially true in root meristem growth that is regulated by intertwined nitrate, phytohormones, and glucose-TOR signaling pathways. Furthermore, the nitrate transcriptional hierarchy is emerging. Nitrate regulators in primary nitrate signaling can individually and combinatorially control downstream transcriptional networks and hormonal pathways for signal propagation and amplification. Under the new paradigms, nitrate-induced hormone metabolism and signaling deserve fresh examination. The close interplay and convergent regulation of nitrate and hormonal signaling at morphological, physiological, and molecular levels have significant effects on important agronomic traits, especially nutrient-dependent adaptive root system growth and architecture. PMID:29033968

Endophytic fungal association via gibberellins and indole acetic acid can improve plant growth under abiotic stress: an example of Paecilomyces formosus LHL10

PubMed Central

2012-01-01

Background Endophytic fungi are little known for exogenous secretion of phytohormones and mitigation of salinity stress, which is a major limiting factor for agriculture production worldwide. Current study was designed to isolate phytohormone producing endophytic fungus from the roots of cucumber plant and identify its role in plant growth and stress tolerance under saline conditions. Results We isolated nine endophytic fungi from the roots of cucumber plant and screened their culture filtrates (CF) on gibberellins (GAs) deficient mutant rice cultivar Waito-C and normal GAs biosynthesis rice cultivar Dongjin-byeo. The CF of a fungal isolate CSH-6H significantly increased the growth of Waito-C and Dongjin-byeo seedlings as compared to control. Analysis of the CF showed presence of GAs (GA1, GA3, GA4, GA8, GA9, GA12, GA20 and GA24) and indole acetic acid. The endophyte CSH-6H was identified as a strain of Paecilomyces formosus LHL10 on the basis of phylogenetic analysis of ITS sequence similarity. Under salinity stress, P. formosus inoculation significantly enhanced cucumber shoot length and allied growth characteristics as compared to non-inoculated control plants. The hypha of P. formosus was also observed in the cortical and pericycle regions of the host-plant roots and was successfully re-isolated using PCR techniques. P. formosus association counteracted the adverse effects of salinity by accumulating proline and antioxidants and maintaining plant water potential. Thus the electrolytic leakage and membrane damage to the cucumber plants was reduced in the association of endophyte. Reduced content of stress responsive abscisic acid suggest lesser stress convened to endophyte-associated plants. On contrary, elevated endogenous GAs (GA3, GA4, GA12 and GA20) contents in endophyte-associated cucumber plants evidenced salinity stress modulation. Conclusion The results reveal that mutualistic interactions of phytohormones secreting endophytic fungi can ameliorate host plant growth and alleviate adverse effects of salt stress. Such fungal strain could be used for further field trials to improve agricultural productivity under saline conditions. PMID:22235902

Example-based learning: comparing the effects of additionally providing three different integrative learning activities on physiotherapy intervention knowledge.

PubMed

Dyer, Joseph-Omer; Hudon, Anne; Montpetit-Tourangeau, Katherine; Charlin, Bernard; Mamede, Sílvia; van Gog, Tamara

2015-03-07

Example-based learning using worked examples can foster clinical reasoning. Worked examples are instructional tools that learners can use to study the steps needed to solve a problem. Studying worked examples paired with completion examples promotes acquisition of problem-solving skills more than studying worked examples alone. Completion examples are worked examples in which some of the solution steps remain unsolved for learners to complete. Providing learners engaged in example-based learning with self-explanation prompts has been shown to foster increased meaningful learning compared to providing no self-explanation prompts. Concept mapping and concept map study are other instructional activities known to promote meaningful learning. This study compares the effects of self-explaining, completing a concept map and studying a concept map on conceptual knowledge and problem-solving skills among novice learners engaged in example-based learning. Ninety-one physiotherapy students were randomized into three conditions. They performed a pre-test and a post-test to evaluate their gains in conceptual knowledge and problem-solving skills (transfer performance) in intervention selection. They studied three pairs of worked/completion examples in a digital learning environment. Worked examples consisted of a written reasoning process for selecting an optimal physiotherapy intervention for a patient. The completion examples were partially worked out, with the last few problem-solving steps left blank for students to complete. The students then had to engage in additional self-explanation, concept map completion or model concept map study in order to synthesize and deepen their knowledge of the key concepts and problem-solving steps. Pre-test performance did not differ among conditions. Post-test conceptual knowledge was higher (P < .001) in the concept map study condition (68.8 ± 21.8%) compared to the concept map completion (52.8 ± 17.0%) and self-explanation (52.2 ± 21.7%) conditions. Post-test problem-solving performance was higher (P < .05) in the self-explanation (63.2 ± 16.0%) condition compared to the concept map study (53.3 ± 16.4%) and concept map completion (51.0 ± 13.6%) conditions. Students in the self-explanation condition also invested less mental effort in the post-test. Studying model concept maps led to greater conceptual knowledge, whereas self-explanation led to higher transfer performance. Self-explanation and concept map study can be combined with worked example and completion example strategies to foster intervention selection.

Open Land-Use Map: A Regional Land-Use Mapping Strategy for Incorporating OpenStreetMap with Earth Observations

NASA Astrophysics Data System (ADS)

Yang, D.; Fu, C. S.; Binford, M. W.

2017-12-01

The southeastern United States has high landscape heterogeneity, withheavily managed forestlands, highly developed agriculture lands, and multiple metropolitan areas. Human activities are transforming and altering land patterns and structures in both negative and positive manners. A land-use map for at the greater scale is a heavy computation task but is critical to most landowners, researchers, and decision makers, enabling them to make informed decisions for varying objectives. There are two major difficulties in generating the classification maps at the regional scale: the necessity of large training point sets and the expensive computation cost-in terms of both money and time-in classifier modeling. Volunteered Geographic Information (VGI) opens a new era in mapping and visualizing our world, where the platform is open for collecting valuable georeferenced information by volunteer citizens, and the data is freely available to the public. As one of the most well-known VGI initiatives, OpenStreetMap (OSM) contributes not only road network distribution, but also the potential for using this data to justify land cover and land use classifications. Google Earth Engine (GEE) is a platform designed for cloud-based mapping with a robust and fast computing power. Most large scale and national mapping approaches confuse "land cover" and "land-use", or build up the land-use database based on modeled land cover datasets. Unlike most other large-scale approaches, we distinguish and differentiate land-use from land cover. By focusing our prime objective of mapping land-use and management practices, a robust regional land-use mapping approach is developed by incorporating the OpenstreepMap dataset into Earth observation remote sensing imageries instead of the often-used land cover base maps.

OsLOL1, a C2C2-type zinc finger protein, interacts with OsbZIP58 to promote seed germination through the modulation of gibberellin biosynthesis in Oryza sativa.

PubMed

Wu, Jiahe; Zhu, Chuanfeng; Pang, Jinhuan; Zhang, Xiangrong; Yang, Chunlin; Xia, Guixian; Tian, Yingchuan; He, Chaozu

2014-12-01

Seed germination is a key developmental process in the plant life cycle that is influenced by various environmental cues and phytohormones through gene expression and a series of metabolism pathways. In the present study, we investigated a C2C2-type finger protein, OsLOL1, which promotes gibberellin (GA) biosynthesis and affects seed germination in Oryza sativa (rice). We used OsLOL1 antisense and sense transgenic lines to explore OsLOL1 functions. Seed germination timing in antisense plants was restored to wild type when exogenous GA3 was applied. The reduced expression of the GA biosynthesis gene OsKO2 and the accumulation of ent-kaurene were observed during germination in antisense plants. Based on yeast two-hybrid and firefly luciferase complementation analyses, OsLOL1 interacted with the basic leucine zipper protein OsbZIP58. The results from electrophoretic mobility shift and dual-luciferase reporter assays showed that OsbZIP58 binds the G-box cis-element of the OsKO2 promoter and activates LUC reporter gene expression, and that interaction between OsLOL1 and OsbZIP58 activates OsKO2 gene expression. In addition, OsLOL1 decreased SOD1 gene expression and accelerated programmed cell death (PCD) in the aleurone layer of rice grains. These findings demonstrate that the interaction between OsLOL1 and OsbZIP58 influences GA biosynthesis through the activation of OsKO2 via OsbZIP58, thereby stimulating aleurone PCD and seed germination. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

The Rice Transcription Factor WRKY53 Suppresses Herbivore-Induced Defenses by Acting as a Negative Feedback Modulator of Mitogen-Activated Protein Kinase Activity1

PubMed Central

Hu, Lingfei; Ye, Meng; Zhang, Tongfang; Zhou, Guoxin; Wang, Qi; Lu, Jing

2015-01-01

The mechanisms by which herbivore-attacked plants activate their defenses are well studied. By contrast, little is known about the regulatory mechanisms that allow them to control their defensive investment and avoid a defensive overshoot. We characterized a rice (Oryza sativa) WRKY gene, OsWRKY53, whose expression is rapidly induced upon wounding and induced in a delayed fashion upon attack by the striped stem borer (SSB) Chilo suppressalis. The transcript levels of OsWRKY53 are independent of endogenous jasmonic acid but positively regulated by the mitogen-activated protein kinases OsMPK3/OsMPK6. OsWRKY53 physically interacts with OsMPK3/OsMPK6 and suppresses their activity in vitro. By consequence, it modulates the expression of defensive, MPK-regulated WRKYs and thereby reduces jasmonic acid, jasmonoyl-isoleucine, and ethylene induction. This phytohormonal reconfiguration is associated with a reduction in trypsin protease inhibitor activity and improved SSB performance. OsWRKY53 is also shown to be a negative regulator of plant growth. Taken together, these results show that OsWRKY53 functions as a negative feedback modulator of MPK3/MPK6 and thereby acts as an early suppressor of induced defenses. OsWRKY53 therefore enables rice plants to control the magnitude of their defensive investment during early signaling. PMID:26453434

Integration of antimicrobial pectin-based edible coating and active modified atmosphere packaging to preserve the quality and microbial safety of fresh-cut persimmon (Diospyros kaki Thunb. cv. Rojo Brillante).

PubMed

Sanchís, Elena; Ghidelli, Christian; Sheth, Chirag C; Mateos, Milagros; Palou, Lluís; Pérez-Gago, María B

2017-01-01

The greatest hurdle to the commercial marketing of fresh-cut fruits is related to their higher susceptibility to enzymatic browning, tissue softening, and microbial growth. The aim of this study was to test the efficacy of a pectin-based edible coating and low oxygen modified atmosphere packaging (MAP) to control enzymatic browning and reduce microbial growth of fresh-cut 'Rojo Brillante' persimmon. The survival of Escherichia coli, Salmonella enteritidis and Listeria monocytogenes artificially inoculated on fresh-cut fruit was also assessed. The pectin coating was amended with 500 IU mL -1 nisin (NI) as antimicrobial agent and 10 g kg -1 citric acid and 10 g kg -1 calcium chloride as anti-browning and firming agents, respectively. Persimmon slices were dipped in the coating or in water (control) and packed under 5 kPa O 2 (MAP) or in ambient atmosphere for up to 9 days at 5 °C. Microbial growth, package gas composition, colour, firmness, polyphenol oxidase activity, visual quality and overall sensory flavour of persimmon slices were measured during storage. Coating application combined with active MAP significantly reduced the CO 2 emission and O 2 consumption in the package. The coating was effective in reducing browning and also inhibited the growth of mesophilic aerobic bacteria. Coating also reduced the populations of E. coli, S. enteritidis and L. monocytogenes. The combination of the pectin-based edible coating and active MAP proved to be the most effective treatment to maintain the sensory and microbiological quality of persimmon slices for more than 9 days of storage. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Ranking the Difficulty Level of the Knowledge Units Based on Learning Dependency

ERIC Educational Resources Information Center

Liu, Jun; Sha, Sha; Zheng, Qinghua; Zhang, Wei

2012-01-01

Assigning difficulty level indicators to the knowledge units helps the learners plan their learning activities more efficiently. This paper focuses on how to use the topology of a knowledge map to compute and rank the difficulty levels of knowledge units. Firstly, the authors present the hierarchical structure and properties of the knowledge map.…

Using a Modelling Language for Supporting University Students' Orienting Activity When Studying Research Methods

ERIC Educational Resources Information Center

Kosonen, Kari; Ilomäki, Liisa; Lakkala, Minna

2015-01-01

The present study focuses on examining how digitally guided conceptual mapping can be used in orienting students in higher education to learn complex domain content and practices. The outcomes of conceptual mapping were investigated as the orienting bases created by the students that used digitalized conceptual tools to construct an external…

Spatially distributed rockfall activity inferred from talus deposits and corresponding rockwall areas in the Gradenbach catchment (Schober Mountains, Austria)

NASA Astrophysics Data System (ADS)

Götz, Joachim; Buckel, Johannes; Heckmann, Tobias

2013-04-01

The analysis of alpine sediment cascades requires the identification, differentiation and quantification of sediment sources, storages, and transport processes. This study deals with the origin of alpine sediment transfer and relates primary talus deposits to corresponding rockwall source areas within the Gradenbach catchment (Schober Mountains, Austrian Alps). Sediment storage landforms are based on a detailed geomorphological map of the catchment which was generated to analyse the sediment transfer system. Mapping was mainly performed in the field and supplemented by post-mapping analysis using LIDAR data and digital orthophotos. A fundamental part of the mapping procedure was to capture additional landform-based information with respect to morphometry, activity and connectivity. The applied procedure provides a detailed inventory of sediment storage landforms including additional information on surface characteristics, dominant and secondary erosion and deposition processes, process activity and sediment storage coupling. We develop the working hypothesis that the present-day surface area ratio between rockfall talus (area as a proxy for volume, backed by geophysical analysis of selected talus cones) and corresponding rockwall source area is a measure of rockfall activity since deglaciation; large talus cones derived from small rockwall catchments indicate high activity, while low activity can be inferred where rockfall from large rock faces has created only small deposits. The surface area ratio of talus and corresponding rockwalls is analysed using a landform-based and a process-based approach. For the landform-based approach, we designed a GIS procedure which derives the (hydrological) catchment area of the contact lines of talus and rockwall landforms in the geomorphological map. The process-based approach simulates rockfall trajectories from steep (>45°) portions of a DEM generated by a random-walk rockfall model. By back-tracing those trajectories that end on a selected talus landform, the 'rockfall contributing area' is delineated; this approach takes account of the stochastic nature of rockfall trajectories and is able to identify, for example, rockfall delivery from one rockwall segment to multiple talus landforms (or from multiple rockfall segments to the same deposit, respectively). Using both approaches, a total of 290 rockwall-talus-subsystems are statistically analysed indicating a constant relationship between rockfall source areas and corresponding areas of talus deposits of almost 1:1. However, certain rockwall-talus-subsystems deviate from this correlation since sediment storage landforms of similar size originate from varying rockwall source areas and vice versa. This varying relationship is assumed to be strongly controlled by morphometric parameters, such as rockwall slope, altitudinal interval, and aspect. The impact of these parameters on the surface area ratio will be finally discussed.

Nitrosative/oxidative stress conditions regulate thioredoxin-interacting protein (TXNIP) expression and thioredoxin-1 (TRX-1) nuclear localization.

PubMed

Ogata, Fernando Toshio; Batista, Wagner Luiz; Sartori, Adriano; Gesteira, Tarsis Ferreira; Masutani, Hiroshi; Arai, Roberto Jun; Yodoi, Junji; Stern, Arnold; Monteiro, Hugo Pequeno

2013-01-01

Thioredoxin (TRX-1) is a multifunctional protein that controls the redox status of other proteins. TRX-1 can be found in the extracellular milieu, cytoplasm and nucleus, and it has distinct functions in each environment. Previously, we studied the intracellular localization of TRX-1 and its relationship with the activation of the p21Ras-ERK1/2 MAP Kinases signaling pathway. In situations where this pathway was activated by stress conditions evoked by a nitrosothiol, S-nitroso-N-acetylpenicillamine (SNAP), TRX-1 accumulated in the nuclear compartment due to nitrosylation of p21Ras and activation of downstream ERK1/2 MAP kinases. Presently, we demonstrate that ERK1/2 MAP Kinases activation and spatial distribution within cells trigger TRX-1 nuclear translocation through down-regulation of the physiological inhibitor of TRX-1, Thioredoxin Interacting Protein (TXNIP). Once activated by the oxidants, SNAP and H₂O₂, the ERK1/2 MAP kinases migrate to the nucleus. This is correlated with down-regulation of TXNIP. In the presence of the MEK inhibitors (PD98059 or UO126), or in cells transfected with the Protein Enriched in Astrocytes (PEA-15), a cytoplasmic anchor of ERK1/2 MAP kinases, TRX-1 nuclear migration and TXNIP down-regulation are no longer observed in cells exposed to oxidants. On the other hand, over-expression of TXNIP abolishes nuclear migration of TRX-1 under nitrosative/oxidative stress conditions, whereas gene silencing of TXNIP facilitates nuclear migration even in the absence of stress conditions. Studies based on the TXNIP promoter support this regulation. In conclusion, changes in TRX-1 compartmentalization under nitrosative/oxidative stress conditions are dependent on the expression levels of TXNIP, which are regulated by cellular compartmentalization and activation of the ERK1/2 MAP kinases.

Datum Transformation of Spatial Data and Application in Cadastre

NASA Astrophysics Data System (ADS)

Kısa, A.; Erkek, B.; Ekin, L.

2012-07-01

In Turkey, cadastral works have been started with local-based works in 1924 and speeded up after 1950's by using photogrammetry. Different measurement methods, coordinate systems and scales have been used in these works. As a result of primary cadastral activities two main products are generated; cadastral maps and title deeds. After this, cadastral data live on the maps, by cadastral activities carried out by cadastral offices and title deed data live on the registrations by land registration activities carried out by land registration offices. Up to 2005 different references systems such as local (graphic) and ED50 have been used for Cadastral maps production. 2000's Land Registry and Cadastre Information System (TAKBİS) Project has started as a pilot application by Land Registry and Cadastre (TKGM). After completion of pilot project spreading activities started in 2005 and still has been ongoing. On the other hand The government has taken the decision to finish primary cadastral activities within three years. The primary cadastral activities completed at the end of 2008. And also TKGM has completed metadata portal in 2008. At last, cadastral map updating (renovation) started in 2009 by using digital orthophoto with 30 cm GSD. Today people have great expectations in accomplishing digital cadastral services, they need correct, reliable, easy and quick accessible land register and cadastral survey information. Even such request expressed in INPIRE directive by using ISO 191XX data standards. This means we have great hard work for spatial data conversion, datum and data transformation for map and cadastral data harmonization. This paper presents results of investigation of used cadastral maps and used datums of the TKGM and possible transformation methods of datum and some recommendations for future applications.

CsMAP34, a teleost MAP with dual role: A promoter of MASP-assisted complement activation and a regulator of immune cell activity.

PubMed

Li, Mo-Fei; Li, Jun; Sun, Li

2016-12-23

In teleost fish, the immune functions of mannan-binding lectin (MBL) associated protein (MAP) and MBL associated serine protease (MASP) are scarcely investigated. In the present study, we examined the biological properties both MAP (CsMAP34) and MASP (CsMASP1) molecules from tongue sole (Cynoglossus semilaevis). We found that CsMAP34 and CsMASP1 expressions occurred in nine different tissues and were upregulated by bacterial challenge. CsMAP34 protein was detected in blood, especially during bacterial infection. Recombinant CsMAP34 (rCsMAP34) bound C. semilaevis MBL (rCsBML) when the latter was activated by bacteria, while recombinant CsMASP1 (rCsMASP1) bound activated rCsBML only in the presence of rCsMAP34. rCsMAP34 stimulated the hemolytic and bactericidal activities of serum complement, whereas anti-CsMAP34 antibody blocked complement activities. Knockdown of CsMASP1 in C. semilaevis resulted in significant inhibition of complement activities. Furthermore, rCsMAP34 interacted directly with peripheral blood leukocytes (PBL) and enhanced the respiratory burst, acid phosphatase activity, chemotactic activity, and gene expression of PBL. These results indicate for the first time that a teleost MAP acts one hand as a regulator that promotes the lectin pathway of complement activation via its ability to recruit MBL to MASP, and other hand as a modulator of immune cell activity.

Anamolous ionospheric TEC variations prior to the Indonesian earthquake (M 7.1) of November 15, 2014

NASA Astrophysics Data System (ADS)

Alcay, Salih

2017-05-01

This paper investigates preearthquake ionospheric variations with the use of TEC of Global Ionospheric Maps (GIMs) and regional maps based on Precise Point Positioning (PPP) during the 7.1-M Indonesian earthquake that occurred on November 15, 2014. TEC maps corresponding to 10 days before to 4 days after the event were examined. In addition, a time series of TEC values according to the PPP maps were also evaluated. In addition to GIMs, it was possible to detect TEC variations with PPP maps. The results showed that ionospheric TEC decreased strikingly 4 days prior to the earthquake. This TEC variation was highly likely related to seismic activity.

Analogical-mapping-based comparison tasks as a scaffold for argumentation

NASA Astrophysics Data System (ADS)

Emig, Brandon R.

Given the centrality of the argumentation process to science and consequent importance to science education, inviting science students to engage in argumentation and scaffolding that argumentation in order that it lead to learning and not frustration is important. The present research invites small groups of science content learners (54 preservice elementary teachers at a large research university) to use analogical-mapping-based comparison tasks in service of argumentation to determine which of two possible analogues, in this case simple machines, is most closely related to a third. These activities and associated instruction scaffolded student small-groups' argumentation in four ways: (1) supporting new analogical correspondences on the heels of prior correspondences; (2) discerning definitions and descriptions for simple machine elements; (3) identifying and dealing with ambiguity in potential correspondences; and (4) making reflections on prior analogical correspondences in service of their final arguments. Analogical-mapping-based comparison activities scaffolded student small groups both in their argumentation and in content learning about simple machines. Implications, limitations, and directions for future related research are also discussed.