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Sample records for modified maize expressing

  1. Transportable data from non-target arthropod field studies for the environmental risk assessment of genetically modified maize expressing an insecticidal double-stranded RNA.

    PubMed

    Ahmad, Aqeel; Negri, Ignacio; Oliveira, Wladecir; Brown, Christopher; Asiimwe, Peter; Sammons, Bernard; Horak, Michael; Jiang, Changjian; Carson, David

    2016-02-01

    As part of an environmental risk assessment, the potential impact of genetically modified (GM) maize MON 87411 on non-target arthropods (NTAs) was evaluated in the field. MON 87411 confers resistance to corn rootworm (CRW; Diabrotica spp.) by expressing an insecticidal double-stranded RNA (dsRNA) transcript and the Cry3Bb1 protein and tolerance to the herbicide glyphosate by producing the CP4 EPSPS protein. Field trials were conducted at 14 sites providing high geographic and environmental diversity within maize production areas from three geographic regions including the U.S., Argentina, and Brazil. MON 87411, the conventional control, and four commercial conventional reference hybrids were evaluated for NTA abundance and damage. Twenty arthropod taxa met minimum abundance criteria for valid statistical analysis. Nine of these taxa occurred in at least two of the three regions and in at least four sites across regions. These nine taxa included: aphid, predatory earwig, lacewing, ladybird beetle, leafhopper, minute pirate bug, parasitic wasp, sap beetle, and spider. In addition to wide regional distribution, these taxa encompass the ecological functions of herbivores, predators and parasitoids in maize agro-ecosystems. Thus, the nine arthropods may serve as representative taxa of maize agro-ecosystems, and thereby support that analysis of relevant data generated in one region can be transportable for the risk assessment of the same or similar GM crop products in another region. Across the 20 taxa analyzed, no statistically significant differences in abundance were detected between MON 87411 and the conventional control for 123 of the 128 individual-site comparisons (96.1%). For the nine widely distributed taxa, no statistically significant differences in abundance were detected between MON 87411 and the conventional control. Furthermore, no statistically significant differences were detected between MON 87411 and the conventional control for 53 out of 56 individual

  2. Fatty acid patterns of genetically modified Cry3Bb1 expressing Bt-maize MON88017 and its near-isogenic line.

    PubMed

    Poerschmann, Juergen; Rauschen, Stefan; Langer, Uwe; Augustin, Juergen; Górecki, Tadeusz

    2009-01-14

    Fatty acid (FA) profiles of the Bt-maize line MON88017 expressing the Cry3Bb1 protein and its near-isogenic line DKC5143 were examined. Plant compartments under study included leaves taken from different internodes and roots. Sample preparation involved pressurized liquid extraction (PLE) of the biomass, transmethylation of the extracted lipids to give fatty acid methyl esters (FAMEs), and finally GC-MS analysis. The essential quality parameters for the FA profiles included total FA and sum of saturated FA, as well as double-bond index (DBI). FA profiles of the roots--characterized by high concentrations of homomorphic FA including palmitic and stearic acid, along with low concentrations of polyunsaturated surrogates--revealed high similarity between the genetically modified and the near-isogenic line. In contrast, FA profiles of the leaves showed significant differences: higher total FA concentrations and higher DBI were observed for the near-isogenic line. This was overwhelmingly associated with lower concentrations of alpha-linolenic acid (18:3omega3,6,9ccc) in the genetically modified leaf samples. These differences were particularly pronounced for leaves taken from the fourth elongated, above-ground internode. Given the large reported variability in the population of maize lines, MON88017 and its near-isogenic line can be regarded as equivalent with regard to their fatty acid profiles, despite the differences observed for the leaves. Further experiments are needed to assess whether the genetic modification of Bt-maize plants might induce unintended effects with regard to FA profiles. PMID:19067518

  3. Co-expression of a modified maize ribosome-inactivating protein and a rice basic chitinase gene in transgenic rice plants confers enhanced resistance to sheath blight.

    PubMed

    Kim, Ju-Kon; Jang, In-Cheol; Wu, Ray; Zuo, Wei-Neng; Boston, Rebecca S; Lee, Yong-Hwan; Ahn, Il-Pyung; Nahm, Baek Hie

    2003-08-01

    Chitinases, beta-1,3-glucanases, and ribosome-inactivating proteins are reported to have antifungal activity in plants. With the aim of producing fungus-resistant transgenic plants, we co-expressed a modified maize ribosome-inactivating protein gene, MOD1, and a rice basic chitinase gene, RCH10, in transgenic rice plants. A construct containing MOD1 and RCH10 under the control of the rice rbcS and Act1 promoters, respectively, was co-transformed with a plasmid containing the herbicide-resistance gene bar as a selection marker into rice by particle bombardment. Several transformants analyzed by genomic Southern-blot hybridization demonstrated integration of multiple copies of the foreign gene into rice chromosomes. Immunoblot experiments showed that MOD1 formed approximately 0.5% of the total soluble protein in transgenic leaves. RCH10 expression was examined using the native polyacrylamide-overlay gel method, and high RCH10 activity was observed in leaf tissues where endogenous RCH10 is not expressed. R1 plants were analyzed in a similar way, and the Southern-blot patterns and levels of transgene expression remained the same as in the parental line. Analysis of the response of R2 plants to three fungal pathogens of rice, Rhizoctonia solani, Bipolaris oryzae, and Magnaporthe grisea, indicated statistically significant symptom reduction only in the case of R. solani (sheath blight). The increased resistance co-segregated with herbicide tolerance, reflecting a correlation between the resistance phenotype and transgene expression. PMID:12885168

  4. Many maize genes are expressed in an oat background carrying a specific maize chromosome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oat-maize addition (OMA) lines are derived from oat x maize sexual hybrids in which individual maize chromosomes have been retained in plants containing a full complement of oat chromosomes. Many of the OMA lines display specific phenotypes, which indicate that maize genes are likely expressed and c...

  5. Digital gene expression signatures for maize development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genome-wide expression signatures detect specific perturbations in developmental programs and contribute to functional resolution of key regulatory networks. In maize (Zea mays) inflorescences, mutations in the RAMOSA (RA) genes affect determinacy of axillary meristems and thus alter branching patt...

  6. Unconventional P-35S sequence identified in genetically modified maize.

    PubMed

    Al-Hmoud, Nisreen; Al-Husseini, Nawar; Ibrahim-Alobaide, Mohammed A; Kübler, Eric; Farfoura, Mahmoud; Alobydi, Hytham; Al-Rousan, Hiyam

    2014-01-01

    The Cauliflower Mosaic Virus 35S promoter sequence, CaMV P-35S, is one of several commonly used genetic targets to detect genetically modified maize and is found in most GMOs. In this research we report the finding of an alternative P-35S sequence and its incidence in GM maize marketed in Jordan. The primer pair normally used to amplify a 123 bp DNA fragment of the CaMV P-35S promoter in GMOs also amplified a previously undetected alternative sequence of CaMV P-35S in GM maize samples which we term V3. The amplified V3 sequence comprises 386 base pairs and was not found in the standard wild-type maize, MON810 and MON 863 GM maize. The identified GM maize samples carrying the V3 sequence were found free of CaMV when compared with CaMV infected brown mustard sample. The data of sequence alignment analysis of the V3 genetic element showed 90% similarity with the matching P-35S sequence of the cauliflower mosaic virus isolate CabbB-JI and 99% similarity with matching P-35S sequences found in several binary plant vectors, of which the binary vector locus JQ693018 is one example. The current study showed an increase of 44% in the incidence of the identified 386 bp sequence in GM maize sold in Jordan's markets during the period 2009 and 2012. PMID:24495911

  7. Real-time quantitative polymerase chain reaction methods for four genetically modified maize varieties and maize DNA content in food.

    PubMed

    Brodmann, Peter D; Ilg, Evelyn C; Berthoud, Hélène; Herrmann, Andre

    2002-01-01

    Quantitative detection methods are needed for enforcement of the recently introduced labeling threshold for genetically modified organisms (GMOs) in food ingredients. This labeling threshold, which is set to 1% in the European Union and Switzerland, must be applied to all approved GMOs. Four different varieties of maize are approved in the European Union: the insect-resistant Bt176 maize (Maximizer), Btl 1 maize, Mon810 (YieldGard) maize, and the herbicide-tolerant T25 (Liberty Link) maize. Because the labeling must be considered individually for each ingredient, a quantitation system for the endogenous maize content is needed in addition to the GMO-specific detection systems. Quantitative real-time polymerase chain reaction detection methods were developed for the 4 approved genetically modified maize varieties and for an endogenous maize (invertase) gene system. PMID:12083257

  8. Individual detection of genetically modified maize varieties in non-identity-preserved maize samples.

    PubMed

    Akiyama, Hiroshi; Sakata, Kozue; Kondo, Kazunari; Tanaka, Asako; Liu, Ming S; Oguchi, Taichi; Furui, Satoshi; Kitta, Kazumi; Hino, Akihiro; Teshima, Reiko

    2008-03-26

    In many countries, the labeling of grains and feed- and foodstuffs is mandatory if the genetically modified organism (GMO) content exceeds a certain level of approved GM varieties. The GMO content in a maize sample containing the combined-trait (stacked) GM maize as determined by the currently available methodology is likely to be overestimated. However, there has been little information in the literature on the mixing level and varieties of stacked GM maize in real sample grains. For the first time, the GMO content of non-identity-preserved (non-IP) maize samples imported from the United States has been successfully determined by using a previously developed individual kernel detection system coupled to a multiplex qualitative PCR method followed by multichannel capillary gel electrophoresis system analysis. To clarify the GMO content in the maize samples imported from the United States, determine how many stacked GM traits are contained therein, and which GM trait varieties frequently appeared in 2005, the GMO content (percent) on a kernel basis and the varieties of the GM kernels in the non-IP maize samples imported from the United States were investigated using the individual kernel analysis system. The average (+/-standard deviation) of the GMO contents on a kernel basis in five non-IP sample lots was determined to be 51.0+/-21.6%, the percentage of a single GM trait grains was 39%, and the percentage of the stacked GM trait grains was 12%. The MON810 grains and NK603 grains were the most frequent varieties in the single GM traits. The most frequent stacked GM traits were the MON810xNK603 grains. In addition, the present study would provide the answer and impact for the quantification of GM maize content in the GM maize kernels on labeling regulation. PMID:18298063

  9. Potential anthranilate modifying enzymes of maize mutant bf-1

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seedlings of maize mutant bf-1 exhibit blue fluorescence and a distinct grape odor due to an accumulation of methyl anthranilate and other anthranilate related compounds. The bf-1 also expresses a feedback insensitive anthranilate synthase. Previously, we identified a unique mutation in anthranila...

  10. Functional diversity of staphylinid beetles (Coleoptera: Staphylinidae) in maize fields: testing the possible effect of genetically modified, insect resistant maize.

    PubMed

    Svobodová, Z; Skoková Habuštová, O; Boháč, J; Sehnal, F

    2016-08-01

    Staphylinid beetles are recommended bioindicators for the pre-market environmental risk assessment of genetically modified (GM) insect protected maize expressing the Cry3Bb1 toxin. Our multiannual study is a unique European analysis of a staphylinid community within a 14 ha maize field. GM maize, its near-isogenic hybrid (with or without insecticide treatment), and two other reference hybrids were each grown in five 0.5 ha plots. The opportunity for exposure to Cry toxin from plant residues ploughed into the soil was shown by the presence of saprophagous dipteran larvae that are common prey of predatory staphylinid species and hosts of the parasitoid species. 2587 individuals belonging to 77 staphylinid species were sampled using pitfall traps. Lesteva longoelytrata (31%), Oxypoda acuminata (12%), Aloconota sulcifrons (8%) and Anotylus rugosus (7%) were the most abundant beetles in the field. Bionomics, food specialization, temperature requirements and size group were assigned for 25 most common species. These traits determine the occurrence of staphylinid beetles in the field, the food sources they could utilize and thus also their likely contact with the Cry3Bb1 toxin. Statistical analysis of activity abundance, Rao indices and multivariate analysis of distribution of particular categories of functional traits in the field showed negligible effects of the experimental treatments, including the GM maize, upon the staphylinid community. Staphylinid beetles represent a considerably diverse part of epigeic field fauna with wide food specialization; these features render them suitable for the assessment of environmental safety of GM insect protected maize. However, the availability of prey and the presence of particular staphylinid species and their abundance are highly variable; this complicates the interpretation of the results. PMID:26781035

  11. Lack of Detectable Allergenicity in Genetically Modified Maize Containing “Cry” Proteins as Compared to Native Maize Based on In Silico & In Vitro Analysis

    PubMed Central

    Mathur, Chandni; Kathuria, Pooran C.; Dahiya, Pushpa; Singh, Anand B.

    2015-01-01

    Background Genetically modified, (GM) crops with potential allergens must be evaluated for safety and endogenous IgE binding pattern compared to native variety, prior to market release. Objective To compare endogenous IgE binding proteins of three GM maize seeds containing Cry 1Ab,1Ac,1C transgenic proteins with non GM maize. Methods An integrated approach of in silico & in vitro methods was employed. Cry proteins were tested for presence of allergen sequence by FASTA in allergen databases. Biochemical assays for maize extracts were performed. Specific IgE (sIgE) and Immunoblot using food sensitized patients sera (n = 39) to non GM and GM maize antigens was performed. Results In silico approaches, confirmed for non sequence similarity of stated transgenic proteins in allergen databases. An insignificant (p> 0.05) variation in protein content between GM and non GM maize was observed. Simulated Gastric Fluid (SGF) revealed reduced number of stable protein fractions in GM then non GM maize which might be due to shift of constituent protein expression. Specific IgE values from patients showed insignificant difference in non GM and GM maize extracts. Five maize sensitized cases, recognized same 7 protein fractions of 88-28 kD as IgE bindng in both GM and non-GM maize, signifying absence of variation. Four of the reported IgE binding proteins were also found to be stable by SGF. Conclusion Cry proteins did not indicate any significant similarity of >35% in allergen databases. Immunoassays also did not identify appreciable differences in endogenous IgE binding in GM and non GM maize. PMID:25706412

  12. Event-specific quantitative detection of nine genetically modified maizes using one novel standard reference molecule.

    PubMed

    Yang, Litao; Guo, Jinchao; Pan, Aihu; Zhang, Haibo; Zhang, Kewei; Wang, Zhengming; Zhang, Dabing

    2007-01-10

    With the development of genetically modified organism (GMO) detection techniques, the Polymerase Chain Reaction (PCR) technique has been the mainstay for GMO detection, and real-time PCR is the most effective and important method for GMO quantification. An event-specific detection strategy based on the unique and specific integration junction sequences between the host plant genome DNA and the integrated gene is being developed for its high specificity. This study establishes the event-specific detection methods for TC1507 and CBH351 maizes. In addition, the event-specific TaqMan real-time PCR detection methods for another seven GM maize events (Bt11, Bt176, GA21, MON810, MON863, NK603, and T25) were systematically optimized and developed. In these PCR assays, the fluorescent quencher, TAMRA, was dyed on the T-base of the probe at the internal position to improve the intensity of the fluorescent signal. To overcome the difficulties in obtaining the certified reference materials of these GM maizes, one novel standard reference molecule containing all nine specific integration junction sequences of these GM maizes and the maize endogenous reference gene, zSSIIb, was constructed and used for quantitative analysis. The limits of detection of these methods were 20 copies for these different GM maizes, the limits of quantitation were about 20 copies, and the dynamic ranges for quantification were from 0.05 to 100% in 100 ng of DNA template. Furthermore, nine groups of the mixed maize samples of these nine GM maize events were quantitatively analyzed to evaluate the accuracy and precision. The accuracy expressed as bias varied from 0.67 to 28.00% for the nine tested groups of GM maize samples, and the precision expressed as relative standard deviations was from 0.83 to 26.20%. All of these indicated that the established event-specific real-time PCR detection systems and the reference molecule in this study are suitable for the identification and quantification of these GM

  13. Visualisation of plastids in endosperm, pollen and roots of transgenic wheat expressing modified GFP fused to transit peptides from wheat SSU RubisCO, rice FtsZ and maize ferredoxin III proteins.

    PubMed

    Primavesi, Lucia F; Wu, Huixia; Mudd, Elisabeth A; Day, Anil; Jones, Huw D

    2008-08-01

    The ability to target marker proteins to specific subcellular compartments is a powerful research tool to study the structure and development of organelles. Here transit sequences from nuclear-encoded, plastid proteins, namely rice FtsZ, maize non-photosynthetic ferredoxin III (FdIII) and the small subunit of RubisCO were used to target a modified synthetic GFP (S65G, S72A) to plastids. The localisations of the fusion proteins expressed in transgenic wheat plants and under the control of the rice actin promoter were compared to an untargeted GFP control. GFP fluorescence was localised to non-green plastids in pollen, roots and seed endosperm and detected in isolated leaf chloroplasts using a GFP-specific antibody. Transit peptides appeared to influence the relative fluorescence intensities of plastids in different tissues. This is consistent with differential targeting and/or turnover of GFP fusion proteins in different plastid types. Replacement of GFP sequences with alternative coding regions enables immediate applications of our vectors for academic research and commercial applications. PMID:17710559

  14. [Contamination with genetically modified maize MON863 of processed foods on the market].

    PubMed

    Ohgiya, Yoko; Sakai, Masaaki; Miyashita, Taeko; Yano, Koichi

    2009-06-01

    Genetically modified maize MON863 (MON863), which has passed a safety examination in Japan, is commercially cultivated in the United States as a food and a resource for fuel. Maize is an anemophilous flower, which easily hybridizes. However, an official method for quantifying the content of MON863 has not been provided yet in Japan. We here examined MON863 contamination in maize-processed foods that had no labeling indicating of the use of genetically modified maize.From March 2006 to July 2008, we purchased 20 frozen maize products, 8 maize powder products, 7 canned maize products and 4 other maize processed foods. Three primer pairs named MON 863 primer, MON863-1, and M3/M4 for MON863-specific integrated cassette were used for qualitative polymerase chain reaction (PCR). A primer pair "SSIIb-3" for starch synthase gene was used to confirm the quality of extracted DNA. The starch synthase gene was detected in all samples. In qualitative tests, the MON863-specific fragments were detected in 7 (18%) maize powder products out of the 39 processed foods with all the three primer pairs.We concluded that various maize processed foods on the market were contaminated with MON863. It is important to accumulate further information on MON863 contamination in maize-processed foods that have no label indication of the use of genetically modified maize. PMID:19602862

  15. Position of modifying groups on starch chains of octenylsuccinic anhydride-modified waxy maize starch

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Octenylsuccinic anhydride (OSA)-modified starches with degree of substitution of 0.018 (OS-S-L) and 0.092 (OS-S-H) were prepared from granular native waxy maize starch in an aqueous slurry system. The substitution distribution of OS groups was investigated by enzyme hydrolysis followed by chromatogr...

  16. Structure and expression of maize phytochrome family homeologs.

    PubMed Central

    Sheehan, Moira J; Farmer, Phyllis R; Brutnell, Thomas P

    2004-01-01

    To begin the study of phytochrome signaling in maize, we have cloned and characterized the phytochrome gene family from the inbred B73. Through DNA gel blot analysis of maize genomic DNA and BAC library screens, we show that the PhyA, PhyB, and PhyC genes are each duplicated once in the genome of maize. Each gene pair was positioned to homeologous regions of the genome using recombinant inbred mapping populations. These results strongly suggest that the duplication of the phytochrome gene family in maize arose as a consequence of an ancient tetraploidization in the maize ancestral lineage. Furthermore, sequencing of Phy genes directly from BAC clones indicates that there are six functional phytochrome genes in maize. Through Northern gel blot analysis and a semiquantitative reverse transcriptase polymerase chain reaction assay, we determined that all six phytochrome genes are transcribed in several seedling tissues. However, expression from PhyA1, PhyB1, and PhyC1 predominate in all seedling tissues examined. Dark-grown seedlings express higher levels of PhyA and PhyB than do light-grown plants but PhyC genes are expressed at similar levels under light and dark growth conditions. These results are discussed in relation to phytochrome gene regulation in model eudicots and monocots and in light of current genome sequencing efforts in maize. PMID:15280251

  17. Engineering a thermoregulated intein-modified xylanase into maize for consolidated lignocellulosic biomass processing.

    PubMed

    Shen, Binzhang; Sun, Xueguang; Zuo, Xiao; Shilling, Taran; Apgar, James; Ross, Mary; Bougri, Oleg; Samoylov, Vladimir; Parker, Matthew; Hancock, Elaina; Lucero, Hector; Gray, Benjamin; Ekborg, Nathan A; Zhang, Dongcheng; Johnson, Jeremy C Schley; Lazar, Gabor; Raab, R Michael

    2012-11-01

    Plant cellulosic biomass is an abundant, low-cost feedstock for producing biofuels and chemicals. Expressing cell wall-degrading (CWD) enzymes (e.g. xylanases) in plant feedstocks could reduce the amount of enzymes required for feedstock pretreatment and hydrolysis during bioprocessing to release soluble sugars. However, in planta expression of xylanases can reduce biomass yield and plant fertility. To overcome this problem, we engineered a thermostable xylanase (XynB) with a thermostable self-splicing bacterial intein to control the xylanase activity. Intein-modified XynB (iXynB) variants were selected that have <10% wild-type enzymatic activity but recover >60% enzymatic activity upon intein self-splicing at temperatures >59 °C. Greenhouse-grown xynB maize expressing XynB has shriveled seeds and low fertility, but ixynB maize had normal seeds and fertility. Processing dried ixynB maize stover by temperature-regulated xylanase activation and hydrolysis in a cocktail of commercial CWD enzymes produced >90% theoretical glucose and >63% theoretical xylose yields. PMID:23086202

  18. O-linked glycosylation in maize-expressed human IgA1.

    PubMed

    Karnoup, Anton S; Turkelson, Virgil; Anderson, W H Kerr

    2005-10-01

    O-Linked glycans vary between eukaryotic cell types and play an important role in determining a glycoprotein's properties, including stability, target recognition, and potentially immunogenicity. We describe O-linked glycan structures of a recombinant human IgA1 (hIgA1) expressed in transgenic maize. Up to six proline/hydroxyproline conversions and variable amounts of arabinosylation (Pro/Hyp + Ara) were found in the hinge region of maize-expressed hIgA1 heavy chain (HC) by using a combination of matrix-assisted laser-desorption ionization mass spectrometry (MALDI MS), chromatography, and amino acid analysis. Approximately 90% of hIgA1 was modified in this way. An average molar ratio of six Ara units per molecule of hIgA1 was revealed. Substantial sequence similarity was identified between the HC hinge region of hIgA1 and regions of maize extensin-family of hydroxyproline-rich glycoproteins (HRGP). We propose that because of this sequence similarity, the HC hinge region of maize-expressed hIgA1 can become a substrate for posttranslational conversion of Pro to Hyp by maize prolyl-hydroxylase(s) with the subsequent arabinosylation of the Hyp residues by Hyp-glycosyltransferase(s) in the Golgi apparatus in maize endosperm tissue. The observation of up to six Pro/Hyp hydroxylations combined with extensive arabinosylation in the hIgA1 HC hinge region is well in agreement with the Pro/Hyp hydroxylation model and the Hyp contiguity hypothesis suggested earlier in literature for plant HRGP. For the first time, the extensin-like Hyp/Pro conversion and O-linked arabinosylation are described for a recombinant therapeutic protein expressed in transgenic plants. Our findings are of significance to the field of plant biotechnology and biopharmaceutical industry-developing transgenic plants as a platform for the production of recombinant therapeutic proteins. PMID:15901675

  19. A multiplex PCR method of detecting recombinant DNAs from five lines of genetically modified maize.

    PubMed

    Matsuoka, T; Kuribara, H; Akiyama, H; Miura, H; Goda, Y; Kusakabe, Y; Isshiki, K; Toyoda, M; Hino, A

    2001-02-01

    Seven lines of genetically modified (GM) maize have been authorized in Japan as foods and feeds imported from the USA. We improved a multiplex PCR method described in the previous report in order to distinguish the five lines of GM maize. Genomic DNA was extracted from GM maize with a silica spin column kit, which could reduce experimental time and improve safety in the laboratory and potentially in the environment. We sequenced recombinant DNA (r-DNA) introduced into GM maize, and re-designed new primer pairs to increase the specificity of PCR to distinguish five lines of GM maize by multiplex PCR. A primer pair for the maize intrinsic zein gene (Ze1) was also designed to confirm the presence of amplifiable maize DNA. The lengths of PCR products using these six primer pairs were different. The Ze1 and the r-DNAs from the five lines of GM maize were qualitatively detected in one tube. The specific PCR bands were distinguishable from each other on the basis of the expected length. The r-DNA could be detected from maize samples containing 0.5% of each of the five lines of GM maize. The sensitivity would be acceptable to secure the verification of non-GMO materials and to monitor the reliability of the labeling system. PMID:11383153

  20. Comparative impact of genetically modified and non modified maize (Zea mays L.) on succeeding crop and associated weed.

    PubMed

    Ibrahim, Muhammad; Ahmed, Naseer; Ullah, Faizan; Shinwari, Zabta Khan; Bano, Asghari

    2016-04-01

    This research work documents the comparative impact of genetically modified (GM) (insect resistance) and non modified maize (Zea maysL.) on growth and germination of succeeding crop wheat (Triticum aestivumL.) and associated weed (Avena fatuaL.). The aqueous extracts of both the GM and non-GM maize exhibited higher phenolic content than that of methanolic extracts. Germination percentage and germination index of wheat was significantly decreased by GM methanolic extract (10%) as well as that of non-GM maize at 3% aqueous extract. Similarly germination percentage of weed (Avena fatuaL.) was significantly reduced by application of 3% and 5% methanolic GM extracts. All extracts of GM maize showed non-significant effect on the number of roots, root length and shoot length per plant but 5% and 10% methanolic extracts of non-GM maize significantly increased the number of roots per plant of wheat seedling. Similarly, 10% methanolic extract of GM maize significantly increased the number of roots per plant of weed seedling. Methanolic extracts of GM and non-GM maize (3% and 5%) significantly decreased the protease activity in wheat as compared to untreated control. PMID:24215059

  1. Consequences for Protaphorura armata (Collembola: Onychiuridae) following exposure to genetically modified Bacillus thuringiensis (Bt) maize and non-Bt maize.

    PubMed

    Heckmann, Lars-Henrik; Griffiths, Bryan S; Caul, Sandra; Thompson, Jacqueline; Pusztai-Carey, Marianne; Moar, William J; Andersen, Mathias N; Krogh, Paul Henning

    2006-07-01

    Studies on the effect of genetically modified Bacillus thuringiensis (Bt) crops on true soil dwelling non-target arthropods are scarce. The objective of this study was to assess the influence of a 4-week exposure to two Bt maize varieties (Cry1Ab) Cascade and MEB307 on the collembolan Protaphorura armata. For comparison three non-Bt maize varieties, Rivaldo (isogenic to Cascade), Monumental (isogenic to MEB307) and DK242, and two control diets based on baker's yeast (uncontaminated and contaminated with Bt toxin Cry1Ab) were also tested. Due to a lower C:N ratio, individuals reared on yeast performed significantly better in all of the measured endpoints than those reared on maize. P. armata performed equally well when reared on two Bt and three non-Bt maize varieties. Although there were no negative effects of Bt maize in this experiment, we recommend future studies on Bt crops to focus on species interactions in long-term, multi-species experiments. PMID:16310913

  2. Occurrence and field densities of Coleoptera in the maize herb layer: implications for Environmental Risk Assessment of genetically modified Bt-maize.

    PubMed

    Rauschen, Stefan; Schaarschmidt, Frank; Gathmann, Achim

    2010-10-01

    Beetles (Coleoptera) are a diverse and ecologically important group of insects in agricultural systems. The Environmental Risk Assessment (ERA) of genetically modified Bt-crop varieties with insect resistances thus needs to consider and assess the potential negative impacts on non-target organisms belonging to this group. We analysed data gathered during 6 years of field-release experiments on the impact of two genetically modified Bt-maize varieties (Ostrinia-resistant MON810 and Diabrotica-resistant MON88017) on the occurrence and field densities of Coleoptera, especially the two families Coccinellidae and Chrysomelidae. Based on a statistical analysis aimed at establishing whether Bt-maize varieties are equivalent to their near-isogenic counterparts, we discuss the limitations of using field experiments to assess the effects of Bt-maize on these two beetle families. The densities of most of the beetle families recorded in the herb layer were very low in all growing seasons. Coccinellidae and Chrysomelidae were comparatively abundant and diverse, but still low in numbers. Based on their role as biological control agents, Coccinellidae should be a focus in the ERA of Bt-plants, but given the large natural variability in ladybird densities in the field, most questions need to be addressed in low-tier laboratory tests. Chrysomelidae should play a negligible role in the ERA of Bt-plants, since they occur on-crop as secondary pests only. Species occurring off-crop, however, can be addressed in a similar fashion as non-target Lepidoptera in Cry1Ab expressing Bt-maize. PMID:20012775

  3. Detection of genetically modified maize and soybean in feed samples.

    PubMed

    Meriç, S; Cakır, O; Turgut-Kara, N; Arı, S

    2014-01-01

    Despite the controversy about genetically modified (GM) plants, they are still incrementally cultivated. In recent years, many food and feed products produced by genetic engineering technology have appeared on store shelves. Controlling the production and legal presentation of GM crops are very important for the environment and human health, especially in terms of long-term consumption. In this study, 11 kinds of feed obtained from different regions of Turkey were used for genetic analysis based on foreign gene determination. All samples were screened by conventional polymerase chain reaction (PCR) technique for widely used genetic elements; cauliflower mosaic virus 35S promoter (CaMV35S promoter), and nopaline synthase terminator (T-NOS) sequences for GM plants. After determination of GM plant-containing samples, nested PCR and conventional PCR analysis were performed to find out whether the samples contained Bt176 or GTS-40-3-2 for maize and soy, respectively. As a result of PCR-based GM plant analysis, all samples were found to be transgenic. Both 35S- and NOS-containing feed samples or potentially Bt176-containing samples, in other words, were analyzed with Bt176 insect resistant cryIAb gene-specific primers via nested PCR. Eventually, none of them were found Bt176-positive. On the other hand, when we applied conventional PCR to the same samples with the herbicide resistance CTP4-EPSPS construct-specific primers for transgenic soy variety GTS-40-3-2, we found that all samples were positive for GTS-40-3-2. PMID:24634172

  4. Effect on soil chemistry of genetically modified (GM) vs. non-GM maize.

    PubMed

    Liu, Na; Zhu, Ping; Peng, Chang; Kang, Lingsheng; Gao, Hongjun; Clarke, Nicholas J; Clarke, Jihong Liu

    2010-01-01

    The effects of genetically modified (GM) maize (Zea mays L.) expressing the Bacillus thuringiensis Berliner Cry1Fa2 protein (Bt) and phosphinothricin or glyphosate herbicide tolerance on soil chemistry (organic matter, N, P, K and pH), compared with non-GM controls, were assessed in field and pot experiments. In the field experiment, NH(4)(+) was significantly higher in soil under the crop modified for herbicide tolerance compared to the control (mean values of 11 and 9.6 mg N/kg respectively) while P was significantly higher in soil under the control compared to under the GM crop (mean values of 6.9 and 6.4 dg P/kg, respectively). No significant differences were found as a result of growing Bt/herbicide tolerant maize. In the pot experiment, using soils from three sites (Gongzhuling, Dehui and Huadian), significant effects of using Bt maize instead of conventional maize were found for all three soils. In the Gongzhuling soil, P was significantly higher in soil under the control compared to under the GM crop (mean values of 4.8 and 4.0 dg P/kg, respectively). For the Dehui soil, the pH was significantly higher in soil under the control compared to under the GM crop (mean values for {H(+)} of 1.1 and 2.4 μM for the control and the GM crop respectively). In the Huadian soil, organic matter and total N were both higher in soil under the GM crop than under the control. For organic matter, the mean values were 3.0 and 2.9% for the GM crop and the control, respectively, while for total nitrogen the mean values were 2.02 and 1.96% for the GM crop and the control respectively. Our results indicate that growing GM crops instead of conventional crops may alter soil chemistry, but not greatly, and that effects will vary with both the specific genetic modification and the soil. PMID:21844670

  5. Bt-maize event MON 88017 expressing Cry3Bb1 does not cause harm to non-target organisms.

    PubMed

    Devos, Yann; De Schrijver, Adinda; De Clercq, Patrick; Kiss, József; Romeis, Jörg

    2012-12-01

    This review paper explores whether the cultivation of the genetically modified Bt-maize transformation event MON 88017, expressing the insecticidal Cry3Bb1 protein against corn rootworms (Coleoptera: Chrysomelidae), causes adverse effects to non-target organisms (NTOs) and the ecological and anthropocentric functions they provide. Available data do not reveal adverse effects of Cry3Bb1 on various NTOs that are representative of potentially exposed taxonomic and functional groups, confirming that the insecticidal activity of the Cry3Bb1 protein is limited to species belonging to the coleopteran family of Chrysomelidae. The potential risk to non-target chrysomelid larvae ingesting maize MON 88017 pollen deposited on host plants is minimal, as their abundance in maize fields and the likelihood of encountering harmful amounts of pollen in and around maize MON 88017 fields are low. Non-target adult chrysomelids, which may occasionally feed on maize MON 88017 plants, are not expected to be affected due to the low activity of the Cry3Bb1 protein on adults. Impacts on NTOs caused by potential unintended changes in maize MON 88017 are not expected to occur, as no differences in composition, phenotypic characteristics and plant-NTO interactions were observed between maize MON 88017 and its near-isogenic line. PMID:22576225

  6. Profiling expression changes caused by a segmental aneuploid in maize

    PubMed Central

    Makarevitch, Irina; Phillips, Ronald L; Springer, Nathan M

    2008-01-01

    Background While changes in chromosome number that result in aneuploidy are associated with phenotypic consequences such as Down syndrome and cancer, the molecular causes of specific phenotypes and genome-wide expression changes that occur in aneuploids are still being elucidated. Results We employed a segmental aneuploid condition in maize to study phenotypic and gene expression changes associated with aneuploidy. Maize plants that are trisomic for 90% of the short arm of chromosome 5 and monosomic for a small distal portion of the short arm of chromosome 6 exhibited a phenotypic syndrome that includes reduced stature, tassel morphology changes and the presence of knots on the leaves. The knotted-like homeobox gene knox10, which is located on the short arm of chromosome 5, was shown to be ectopically expressed in developing leaves of the aneuploid plants. Expression profiling revealed that ~40% of the expressed genes in the trisomic region exhibited the expected 1.5 fold increased transcript levels while the remaining 60% of genes did not show altered expression even with increased gene dosage. Conclusion We found that the majority of genes with altered expression levels were located within the chromosomal regions affected by the segmental aneuploidy and exhibits dosage-dependent expression changes. A small number of genes exhibit higher levels of expression change not predicted by the dosage, or display altered expression even though they are not located in the aneuploid regions. PMID:18186930

  7. The maize milkweed pod1 mutant reveals a mechanism to modify organ morphology.

    PubMed

    Johnston, Robyn; Candela, Héctor; Hake, Sarah; Foster, Toshi

    2010-07-01

    Plant lateral organs, such as leaves, have three primary axes of growth-proximal-distal, medial--lateral and adaxial-abaxial (dorsal-ventral). Although most leaves are planar, modified leaf forms, such as the bikeeled grass prophyll, can be found in nature. A detailed examination of normal prophyll development indicates that polarity is established differently in the keels than in other parts of the prophyll. Analysis of the maize HD-ZIPIII gene rolled leaf1 (rld1) suggests that altered expression patterns are responsible for keel outgrowth. Recessive mutations in the maize (Zea mays) KANADI (KAN) gene milkweed pod1 (mwp1), which promotes abaxial cell identity, strongly affect development of the prophyll and silks (fused carpels). The prophyll is reduced to two unfused midribs and the silks are narrow and misshapen. Our data indicate that the prophyll and other fused organs are particularly sensitive to disruptions in adaxial-abaxial polarity. In addition, lateral and proximal-distal growth of most lateral organs is reduced in the mwp1-R mutant, supporting a role for the adaxial-abaxial boundary in promoting growth along both axes. We propose that the adaxial-abaxial patterning mechanism has been co-opted during evolution to generate diverse organ morphologies. PMID:20213690

  8. THE MAIZE UNSTABLE FACTOR FOR ORANGE1 IS A DOMINANT EPIGENETIC MODIFIER OF A TISSUE SPECIFICALLY SILENT ALLELE OF PERICARP COLOR1

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have characterized Ufo1 (unstable factor for orange1), a dominant, allele-specific modifier of expression of the maize pericarp color1 (p1) gene. The p1 gene encodes a Myb-homologous transcriptional activator of genes required for biosynthesis of red phlobaphene pigments. The P1-wr allele speci...

  9. Modification of recombinant maize ChitA chitinase by fungal chitinase-modifying proteins.

    PubMed

    Naumann, Todd A

    2011-05-01

    In commercial maize, there are at least two different alleles of the chiA gene that encode alloforms of ChitA chitinase, a protein that is abundant in developing seed. Both known alloforms are modified by Bz-cmp, a chitinase-modifying protein (cmp) secreted by the fungal pathogen Bipolaris zeicola. One alloform (ChitA-B73) is also modified by Stm-cmp, a protein secreted by the fungal pathogen Stenocarpella maydis, whereas the other (ChitA-LH82) is resistant. The two ChitA alloforms possess six differences or polymorphisms (P1-P6). To determine whether the P2 polymorphism in the chitin-binding domain is responsible for resistance or susceptibility to modification by Stm-cmp, and to determine whether Stm-cmp and Bz-cmp are proteases, heterologous expression strains of the yeast Pichia pastoris that produce recombinant maize ChitA (rChitA) alloforms and mutant rChitAs were created. rChitA alloforms and mutant rChitAs were purified from yeast cultures and used as substrates in assays with Stm-cmp and Bz-cmp. As with native protein, Bz-cmp modified both rChitA-LH82 and rChitA-B73, whereas Stm-cmp modified rChitA-B73 only. Mutant rChitAs, in which the P2 amino acids were changed to those of the other alloform, resulted in a significant exchange in Stm-cmp susceptibility. Amino-terminal sequencing of unmodified and modified rChitA-B73 demonstrated that Stm-cmp cleaves the peptide bond on the amino-terminal side of the P2 alanine, whereas Bz-cmp cleaves in the poly-glycine hinge region, the site of P3. The results demonstrate that Stm-cmp and Bz-cmp are proteases that truncate ChitA chitinase at the amino terminus, but at different sites. Both sites correspond to polymorphisms in the two alloforms, suggesting that the sequence diversity at P2 and P3 is the result of selective pressure to prevent truncation by fungal proteases. PMID:21453431

  10. Comparative proteomic analysis of genetically modified maize grown under different agroecosystems conditions in Brazil

    PubMed Central

    2013-01-01

    Background Profiling technologies allow the simultaneous measurement and comparison of thousands of cell components without prior knowledge of their identity. In the present study, we used two-dimensional gel electrophoresis combined with mass spectrometry to evaluate protein expression of Brazilian genetically modified maize hybrid grown under different agroecosystems conditions. To this effect, leaf samples were subjected to comparative analysis using the near-isogenic non-GM hybrid as the comparator. Results In the first stage of the analysis, the main sources of variation in the dataset were identified by using Principal Components Analysis which correlated most of the variation to the different agroecosystems conditions. Comparative analysis within each field revealed a total of thirty two differentially expressed proteins between GM and non-GM samples that were identified and their molecular functions were mainly assigned to carbohydrate and energy metabolism, genetic information processing and stress response. Conclusions To the best of our knowledge this study represents the first evidence of protein identities with differentially expressed isoforms in Brazilian MON810 genetic background hybrid grown under field conditions. As global databases on outputs from “omics” analysis become available, these could provide a highly desirable benchmark for safety assessments. PMID:24304660

  11. Maize Seed Chitinase is Modified by a Protein Secreted by Bipolaris zeicola

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plants contain defense mechanisms that prevent infection by most fungi. Some specialized fungi have the ability to overcome plant defenses. The Zea mays (maize) seed chitinase ChitA has been previously reported as an antifungal protein. Here we report that ChitA is converted to a modified form by...

  12. Modification of recombinant maize ChitA chitinase by fungal chitinase-modifying proteins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In commercial maize, there are at least two different alleles of the chiA gene that encode alloforms of ChitA chitinase, a protein that is abundant in developing seed. Both known alloforms are modified by Bz-cmp, a protein secreted by the fungal pathogen Bipolaris zeicola. One alloform (ChitA-B73) i...

  13. Position of modifying groups on starch chains of octenylsuccinic anhydride-modified waxy maize starch.

    PubMed

    Bai, Yanjie; Kaufman, Rhett C; Wilson, Jeff D; Shi, Yong-Cheng

    2014-06-15

    Octenylsuccinic anhydride (OSA)-modified starches with a low (0.018) and high (0.092) degree of substitution (DS) were prepared from granular native waxy maize starch in aqueous slurry. The position of OS substituents along the starch chains was investigated by enzyme hydrolysis followed by chromatographic analysis. Native starch and two OS starches with a low and high DS had β-limit values of 55.9%, 52.8%, and 34.4%, respectively. The weight-average molecular weight of the β-limit dextrin from the OS starch with a low DS was close to that of the β-limit dextrin from native starch but lower than that of the β-limit dextrin from the OS starch with a high DS. Debranching of OS starches was incomplete compared with native starch. OS groups in the OS starch with a low DS were located on the repeat units near the branching points, whereas the OS substituents in the OS starch with a high DS occurred both near the branching points and the non-reducing ends. PMID:24491720

  14. Characterization of gene expression profiles in developing kernels of maize (Zea mays) inbred Tex6

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize oligonuleotide microarray was used to analyze the temporal patterns of gene expression in late developmental maize kernels 25 days after pollination (DAP). There was a total of 57,452 70-mer oligonucleotides on the array. We analyzed gene expression profiles in the developing kernels of Tex6, ...

  15. A microarray-based analysis of gene expression profiles of maize kernel during late development stages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize oligonuleotide array was used to analyze the temporal patterns of gene expression in maize kernels during late developmental stages. There is a total of 57,452 70-mer oligonucleotides on the array. In this study, we analyzed gene expression profiles in the process of kernel development of inbr...

  16. Relating significance and relations of differentially expressed genes in response to Aspergillus flavus infection in maize.

    PubMed

    Asters, Matthew C; Williams, W Paul; Perkins, Andy D; Mylroie, J Erik; Windham, Gary L; Shan, Xueyan

    2014-01-01

    Aspergillus flavus is a pathogenic fungus infecting maize and producing aflatoxins that are health hazards to humans and animals. Characterizing host defense mechanism and prioritizing candidate resistance genes are important to the development of resistant maize germplasm. We investigated methods amenable for the analysis of the significance and relations among maize candidate genes based on the empirical gene expression data obtained by RT-qPCR technique from maize inbred lines. We optimized a pipeline of analysis tools chosen from various programs to provide rigorous statistical analysis and state of the art data visualization. A network-based method was also explored to construct the empirical gene expression relational structures. Maize genes at the centers in the network were considered as important candidate genes for maize DNA marker studies. The methods in this research can be used to analyze large RT-qPCR datasets and establish complex empirical gene relational structures across multiple experimental conditions. PMID:24770700

  17. Relating significance and relations of differentially expressed genes in response to Aspergillus flavus infection in maize

    PubMed Central

    Asters, Matthew C.; Williams, W. Paul; Perkins, Andy D.; Mylroie, J. Erik; Windham, Gary L.; Shan, Xueyan

    2014-01-01

    Aspergillus flavus is a pathogenic fungus infecting maize and producing aflatoxins that are health hazards to humans and animals. Characterizing host defense mechanism and prioritizing candidate resistance genes are important to the development of resistant maize germplasm. We investigated methods amenable for the analysis of the significance and relations among maize candidate genes based on the empirical gene expression data obtained by RT-qPCR technique from maize inbred lines. We optimized a pipeline of analysis tools chosen from various programs to provide rigorous statistical analysis and state of the art data visualization. A network-based method was also explored to construct the empirical gene expression relational structures. Maize genes at the centers in the network were considered as important candidate genes for maize DNA marker studies. The methods in this research can be used to analyze large RT-qPCR datasets and establish complex empirical gene relational structures across multiple experimental conditions. PMID:24770700

  18. The maize milkweed pod1 mutant reveals a mechanism to modify organ morphology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A detailed examination of normal prophyll development indicates that polarity is established differently in the keels than in other parts of the prophyll. Analysis of the maize HD-ZIPIII gene rolled leaf1 (rld1) suggests that altered expression patterns are responsible for keel outgrowth. Recessive ...

  19. A look at product development with genetically modified crops: examples from maize.

    PubMed

    Mumm, Rita H

    2013-09-01

    Plant breeding for crop genetic improvement involves the cycle of creating genetic diversity and exploiting that diversity to derive an improved cultivar with outstanding performance for specific traits of interest. Genetic modification through transformation essentially expands the genepool to facilitate access to genes otherwise not available through crossing. Transgenic events are defined by the DNA sequence that has been incorporated into the target genome and the specific point(s) of insertion. In the development of a new transgenic trait, typically many events are generated and evaluated with the aim of identifying one exhibiting consistent trait expression at or above specified thresholds, stable inheritance, and the absence of any negative effects. With transgenic traits for maize, once commercial candidates have been identified, these events are introgressed into elite lines, often through the use of molecular markers that can accelerate the breeding process and aid in producing a quality conversion. Converted elite lines are yield-tested to ensure performance equivalency with their unconverted counterparts. Finally, before commercial sale of seed, quality control monitoring is conducted to ensure event identity and purity and the absence of any unintended events. This monitoring complements other quality control measures to confirm seed viability and line/hybrid purity and uniformity in seed treatments, all in an effort to ensure customer satisfaction and to comply with governmental regulations. Thus, genetically modified (GM) cultivars are subject to significant testing and auditing prior to seed sale and distribution to farmers, more testing and auditing than with non-GM cultivars. PMID:23668783

  20. Detection of genetically modified maize in processed foods sold commercially in iran by qualitative PCR.

    PubMed

    Rabiei, Maryam; Mehdizadeh, Mehrangiz; Rastegar, Hossein; Vahidi, Hossein; Alebouyeh, Mahmoud

    2013-01-01

    Detection of genetically modified organisms (GMOs) in food is an important issue for all the subjects involved in food control and customer's right. Due to the increasing number of GMOs imported to Iran during the past few years, it has become necessary to screen the products in order to determine the identity of the consumed daily foodstuffs. In this study, following the extraction of genomic DNA from processed foods sold commercially in Iran, qualitative PCR was performed to detect genetically modified maize. The recombinant DNA target sequences were detected with primers highly specific for each investigated transgene such as CaMV35s gene, Bt-11, MON810 and Bt-176 separately. Based on the gel electrophoresis results, Bt- 11 and MON810 events were detected in some maize samples, while, in none of them Bt- 176 modified gene was detected. For the first time, the results demonstrate the presence of genetically modified maize in Iranian food products, reinforcing the need for the development of labeling system and valid quantitative methods in routine analyses. PMID:24250568

  1. Detection of Genetically Modified Maize in Processed Foods Sold Commercially in Iran by Qualitative PCR

    PubMed Central

    Rabiei, Maryam; Mehdizadeh, Mehrangiz; Rastegar, Hossein; Vahidi, Hossein; Alebouyeh, Mahmoud

    2013-01-01

    Detection of genetically modified organisms (GMOs) in food is an important issue for all the subjects involved in food control and customer’s right. Due to the increasing number of GMOs imported to Iran during the past few years, it has become necessary to screen the products in order to determine the identity of the consumed daily foodstuffs. In this study, following the extraction of genomic DNA from processed foods sold commercially in Iran, qualitative PCR was performed to detect genetically modified maize. The recombinant DNA target sequences were detected with primers highly specific for each investigated transgene such as CaMV35s gene, Bt-11, MON810 and Bt-176 separately. Based on the gel electrophoresis results, Bt- 11 and MON810 events were detected in some maize samples, while, in none of them Bt- 176 modified gene was detected. For the first time, the results demonstrate the presence of genetically modified maize in Iranian food products, reinforcing the need for the development of labeling system and valid quantitative methods in routine analyses. PMID:24250568

  2. Gene expression profiles of corn developing kernels of Tex6 using maize oligo-microarray

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize oligonuleotide microarray was used to analyze the temporal patterns of gene expression in late developmental maize kernels of Tex6 after 25 days after pollination (DAP). There was a total of 57,452 70-mer oligonucleotides on a set of two array-slides. Because of the resistant traits of Tex6, w...

  3. Loop-mediated isothermal amplification (LAMP) method for detection of genetically modified maize T25.

    PubMed

    Xu, Junyi; Zheng, Qiuyue; Yu, Ling; Liu, Ran; Zhao, Xin; Wang, Gang; Wang, Qinghua; Cao, Jijuan

    2013-11-01

    The loop-mediated isothermal amplification (LAMP) assay indicates a potential and valuable means for genetically modified organism (GMO) detection especially for its rapidity, simplicity, and low cost. We developed and evaluated the specificity and sensitivity of the LAMP method for rapid detection of the genetically modified (GM) maize T25. A set of six specific primers was successfully designed to recognize six distinct sequences on the target gene, including a pair of inner primers, a pair of outer primers, and a pair of loop primers. The optimum reaction temperature and time were verified to be 65°C and 45 min, respectively. The detection limit of this LAMP assay was 5 g kg(-1) GMO component. Comparative experiments showed that the LAMP assay was a simple, rapid, accurate, and specific method for detecting the GM maize T25. PMID:24804053

  4. Loop-mediated isothermal amplification (LAMP) method for detection of genetically modified maize T25

    PubMed Central

    Xu, Junyi; Zheng, Qiuyue; Yu, Ling; Liu, Ran; Zhao, Xin; Wang, Gang; Wang, Qinghua; Cao, Jijuan

    2013-01-01

    The loop-mediated isothermal amplification (LAMP) assay indicates a potential and valuable means for genetically modified organism (GMO) detection especially for its rapidity, simplicity, and low cost. We developed and evaluated the specificity and sensitivity of the LAMP method for rapid detection of the genetically modified (GM) maize T25. A set of six specific primers was successfully designed to recognize six distinct sequences on the target gene, including a pair of inner primers, a pair of outer primers, and a pair of loop primers. The optimum reaction temperature and time were verified to be 65°C and 45 min, respectively. The detection limit of this LAMP assay was 5 g kg−1 GMO component. Comparative experiments showed that the LAMP assay was a simple, rapid, accurate, and specific method for detecting the GM maize T25. PMID:24804053

  5. Expression of Phenylalanine Ammonia Lyase Genes in Maize Lines Differing in Susceptibility to Meloidogyne incognita

    PubMed Central

    Yang, W.; Yan, Y.; Crutcher, F.; Kolomiets, M.

    2014-01-01

    Maize is a well-known host for Meloidogyne incognita, and there is substantial variation in host status among maize genotypes. In previous work it was observed that nematode reproduction increased in the moderately susceptible maize inbred line B73 when the ZmLOX3 gene from oxylipid metabolism was knocked out. Additionally, in this mutant line, use of a nonspecific primer for phenyl alanine ammonialyase (PAL) genes indicated that expression of these genes was reduced in the mutant maize plants whereas expression of several other defense related genes was increased. In this study, we used more specific gene primers to examine the expression of six PAL genes in three maize genotypes that were good, moderate, and poor hosts for M. incognita, respectively. Of the six PAL genes interrogated, two (ZmPAL3 and ZmPAL6) were not expressed in either M. incognita–infected or noninfected roots. Three genes (ZmPAL1, ZmPAL2, and ZmPAL5) were strongly expressed in all three maize lines, in both nematode-infected and noninfected roots, between 2 and 16 d after inoculation (DAI). In contrast, ZmPAL4 was most strongly expressed in the most-resistant maize line W438, was not detected in the most-susceptible maize line CML, and was detected only at 8 DAI in the maize line B73 that supported intermediate levels of reproduction by M. incognita. These observations are consistent with at least one PAL gene playing a role in modulating host status of maize toward M. incognita and suggest a need for additional research to further elucidate this association. PMID:25580029

  6. Comparison of Gene Expressions of Maize Kernel Pathogenesis-Related Proteins in Different Maize Genotypes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxins are carcinogenic mycotoxins produced by the fungus Aspergillus flavus during infection of various grain crops including maize (Zea mays). Contamination of maize with aflatoxins has been shown to be exasperated by late season drought stress. Previous studies have identified numerous resist...

  7. Expression of an anthranilate synthase from maize mutant bf-1 in maize line HiII

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize mutant bf-1 was one of a series of maize mutants generated by radiation from the Bikini Atoll atomic bomb test in 1946. It is characterized by blue fluorescence in seedlings and anthers under ultraviolet illumination and by mutant plants giving off a characteristic grape-like odor due to the ...

  8. Analysis and expression of the alpha-expansin and beta-expansin gene families in maize

    NASA Technical Reports Server (NTRS)

    Wu, Y.; Meeley, R. B.; Cosgrove, D. J.

    2001-01-01

    Expansins comprise a multigene family of proteins in maize (Zea mays). We isolated and characterized 13 different maize expansin cDNAs, five of which are alpha-expansins and eight of which are beta-expansins. This paper presents an analysis of these 13 expansins, as well as an expression analysis by northern blotting with materials from young and mature maize plants. Some expansins were expressed in restricted regions, such as the beta-expansins ExpB1 (specifically expressed in maize pollen) and ExpB4 (expressed principally in young husks). Other expansins such as alpha-expansin Exp1 and beta-expansin ExpB2 were expressed in several organs. The expression of yet a third group was not detected in the selected organs and tissues. An analysis of expansin sequences from the maize expressed sequence tag collection is also presented. Our results indicate that expansin genes may have general, overlapping expression in some instances, whereas in other cases the expression may be highly specific and limited to a single organ or cell type. In contrast to the situation in Arabidopsis, beta-expansins in maize seem to be more numerous and more highly expressed than are alpha-expansins. The results support the concept that beta-expansins multiplied and evolved special functions in the grasses.

  9. Expression of a maize Myb transcription factor driven by a putative silk-specific promoter significantly enhances resistance to Helicoverpa zea in transgenic maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hi II maize (Zea mays) plants were engineered to express maize p1 cDNA, a Myb transcription factor, controlled by a putative silk specific promoter, for secondary metabolite production and corn earworm resistance. Transgene expression did not enhance silk color, but about half of the transformed p...

  10. Finding the joker among the maize endogenous reference genes for genetically modified organism (GMO) detection.

    PubMed

    Paternò, Annalisa; Marchesi, Ugo; Gatto, Francesco; Verginelli, Daniela; Quarchioni, Cinzia; Fusco, Cristiana; Zepparoni, Alessia; Amaddeo, Demetrio; Ciabatti, Ilaria

    2009-12-01

    The comparison of five real-time polymerase chain reaction (PCR) methods targeted at maize ( Zea mays ) endogenous sequences is reported. PCR targets were the alcohol dehydrogenase (adh) gene for three methods and high-mobility group (hmg) gene for the other two. The five real-time PCR methods have been checked under repeatability conditions at several dilution levels on both pooled DNA template from several genetically modified (GM) maize certified reference materials (CRMs) and single CRM DNA extracts. Slopes and R(2) coefficients of all of the curves obtained from the adopted regression model were compared within the same method and among all of the five methods, and the limit of detection and limit of quantitation were analyzed for each PCR system. Furthermore, method equivalency was evaluated on the basis of the ability to estimate the target haploid genome copy number at each concentration level. Results indicated that, among the five methods tested, one of the hmg-targeted PCR systems can be considered equivalent to the others but shows the best regression parameters and a higher repeteability along the dilution range. Thereby, it is proposed as a valid module to be coupled to different event-specific real-time PCR for maize genetically modified organism (GMO) quantitation. The resulting practicability improvement on the analytical control of GMOs is discussed. PMID:19902949

  11. Clarification of colloidal and suspended material in water using triethanolamine modified maize tassels.

    PubMed

    Kinyua, Esther Mbuci; Mwangi, Isaac W; Wanjau, Ruth N; Ngila, J C

    2016-03-01

    Suspended particles in water are a major concern in global pollution management. They affect the appreciation of water due to clarity, photosynthesis, and poor oxygen environment rendering water unsuitable for aquatic animals. Some suspended materials contain functional groups capable of forming complex compounds with metals making them available for poisoning. Such material promotes the growth of bacteria and fouling that give rise to unpleasant taste and odor of the water and thus requires removal. Removal of suspended solids is normally achieved through sedimentation or filtration. However, some suspended colloidal particles are very stable in water and cannot settle while others are able to pass through the filter due to small size, hence difficult to remove. This study investigated the use of triethanolamine-modified maize tassels to form a flocculent for their removal. The modified maize tassels were characterized using Fourier transform infrared (FTIR), and it was found that the triethanolamine was anchored within the cellulose structure of the maize tassels. Clarification parameters such as settling time, reagent dosage, and pH were investigated. The best clarification was at a pH of 6.0 with clearance being less than in 30 min. The optimal flocculent dosage was found to be 3.5 ml of the material, showing that the material has a potential of enhancing clarity in polluted water. PMID:26561324

  12. Maize tassel-modified carbon paste electrode for voltammetric determination of Cu(II).

    PubMed

    Moyo, Mambo; Okonkwo, Jonathan O; Agyei, Nana M

    2014-08-01

    The preparation and application of a practical electrochemical sensor for environmental monitoring and assessment of heavy metal ions in samples is a subject of considerable interest. In this paper, a carbon paste electrode modified with maize tassel for the determination of Cu(II) has been proposed. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to study morphology and identify the functional groups on the modified electrode, respectively. First, Cu(II) was adsorbed on the carbon paste electrode surface at open circuit and voltammetric techniques were used to investigate the electrochemical performances of the sensor. The electrochemical sensor showed an excellent electrocatalytic activity towards Cu(II) at pH 5.0 and by increasing the amount of maize tassel biomass, a maximum response at 1:2.5 (maize tassel:carbon paste; w/w) was obtained. The electrocatalytic redox current of Cu(II) showed a linear response in the range (1.23 μM to 0.4 mM) with the correlation coefficient of 0.9980. The limit of detection and current-concentration sensitivity were calculated to be 0.13 (±0.01) μM and 0.012 (±0.001) μA/μM, respectively. The sensor gave good recovery of Cu(II) in the range from 96.0 to 98.0 % when applied to water samples. PMID:24705875

  13. DNA extraction techniques compared for accurate detection of genetically modified organisms (GMOs) in maize food and feed products.

    PubMed

    Turkec, Aydin; Kazan, Hande; Karacanli, Burçin; Lucas, Stuart J

    2015-08-01

    In this paper, DNA extraction methods have been evaluated to detect the presence of genetically modified organisms (GMOs) in maize food and feed products commercialised in Turkey. All the extraction methods tested performed well for the majority of maize foods and feed products analysed. However, the highest DNA content was achieved by the Wizard, Genespin or the CTAB method, all of which produced optimal DNA yield and purity for different maize food and feed products. The samples were then screened for the presence of GM elements, along with certified reference materials. Of the food and feed samples, 8 % tested positive for the presence of one GM element (NOS terminator), of which half (4 % of the total) also contained a second element (the Cauliflower Mosaic Virus 35S promoter). The results obtained herein clearly demonstrate the presence of GM maize in the Turkish market, and that the Foodproof GMO Screening Kit provides reliable screening of maize food and feed products. PMID:26243938

  14. Earthworms modify microbial community structure and accelerate maize stover decomposition during vermicomposting.

    PubMed

    Chen, Yuxiang; Zhang, Yufen; Zhang, Quanguo; Xu, Lixin; Li, Ran; Luo, Xiaopei; Zhang, Xin; Tong, Jin

    2015-11-01

    In the present study, maize stover was vermicomposted with the epigeic earthworm Eisenia fetida. The results showed that, during vermicomposting process, the earthworms promoted decomposition of maize stover. Analysis of microbial communities of the vermicompost by high-throughput pyrosequencing showed more complex bacterial community structure in the substrate treated by the earthworms than that in the control group. The dominant microbial genera in the treatment with the earthworms were Pseudoxanthomonas, Pseudomonas, Arthrobacter, Streptomyces, Cryptococcus, Guehomyces, and Mucor. Compared to the control group, the relative abundance of lignocellulose degradation microorganisms increased. The results indicated that the earthworms modified the structure of microbial communities during vermicomposting process, activated the growth of lignocellulose degradation microorganisms, and triggered the lignocellulose decomposition. PMID:26139410

  15. Constitutive Expression of the Maize Genes B1 and C1 in Transgenic Hi II Maize Results in Differential Tissue Pigmentation and Generates Resistance to Helicoverpa zea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anthocyanin biosynthesis in maize protects tissues from biotic and abiotic stresses. Constitutive expression of the maize B1 and C1 genes, which induces anthocyanin biosynthesis, resulted in transgenic plants with varied phenotypes. Some colored leaves were substantially resistant to thrips damage...

  16. Gene duplication confers enhanced expression of 27-kDa γ-zein for endosperm modification in quality protein maize.

    PubMed

    Liu, Hongjun; Shi, Junpeng; Sun, Chuanlong; Gong, Hao; Fan, Xingming; Qiu, Fazhan; Huang, Xuehui; Feng, Qi; Zheng, Xixi; Yuan, Ningning; Li, Changsheng; Zhang, Zhiyong; Deng, Yiting; Wang, Jiechen; Pan, Guangtang; Han, Bin; Lai, Jinsheng; Wu, Yongrui

    2016-05-01

    The maize opaque2 (o2) mutant has a high nutritional value but it develops a chalky endosperm that limits its practical use. Genetic selection for o2 modifiers can convert the normally chalky endosperm of the mutant into a hard, vitreous phenotype, yielding what is known as quality protein maize (QPM). Previous studies have shown that enhanced expression of 27-kDa γ-zein in QPM is essential for endosperm modification. Taking advantage of genome-wide association study analysis of a natural population, linkage mapping analysis of a recombinant inbred line population, and map-based cloning, we identified a quantitative trait locus (qγ27) affecting expression of 27-kDa γ-zein. qγ27 was mapped to the same region as the major o2 modifier (o2 modifier1) on chromosome 7 near the 27-kDa γ-zein locus. qγ27 resulted from a 15.26-kb duplication at the 27-kDa γ-zein locus, which increases the level of gene expression. This duplication occurred before maize domestication; however, the gene structure of qγ27 appears to be unstable and the DNA rearrangement frequently occurs at this locus. Because enhanced expression of 27-kDa γ-zein is critical for endosperm modification in QPM, qγ27 is expected to be under artificial selection. This discovery provides a useful molecular marker that can be used to accelerate QPM breeding. PMID:27092004

  17. Gene duplication confers enhanced expression of 27-kDa γ-zein for endosperm modification in quality protein maize

    PubMed Central

    Liu, Hongjun; Shi, Junpeng; Sun, Chuanlong; Gong, Hao; Fan, Xingming; Qiu, Fazhan; Huang, Xuehui; Feng, Qi; Zheng, Xixi; Yuan, Ningning; Li, Changsheng; Zhang, Zhiyong; Deng, Yiting; Wang, Jiechen; Pan, Guangtang; Han, Bin; Lai, Jinsheng; Wu, Yongrui

    2016-01-01

    The maize opaque2 (o2) mutant has a high nutritional value but it develops a chalky endosperm that limits its practical use. Genetic selection for o2 modifiers can convert the normally chalky endosperm of the mutant into a hard, vitreous phenotype, yielding what is known as quality protein maize (QPM). Previous studies have shown that enhanced expression of 27-kDa γ-zein in QPM is essential for endosperm modification. Taking advantage of genome-wide association study analysis of a natural population, linkage mapping analysis of a recombinant inbred line population, and map-based cloning, we identified a quantitative trait locus (qγ27) affecting expression of 27-kDa γ-zein. qγ27 was mapped to the same region as the major o2 modifier (o2 modifier1) on chromosome 7 near the 27-kDa γ-zein locus. qγ27 resulted from a 15.26-kb duplication at the 27-kDa γ-zein locus, which increases the level of gene expression. This duplication occurred before maize domestication; however, the gene structure of qγ27 appears to be unstable and the DNA rearrangement frequently occurs at this locus. Because enhanced expression of 27-kDa γ-zein is critical for endosperm modification in QPM, qγ27 is expected to be under artificial selection. This discovery provides a useful molecular marker that can be used to accelerate QPM breeding. PMID:27092004

  18. Resistance evolution to the first generation of genetically modified Diabrotica-active Bt-maize events by western corn rootworm: management and monitoring considerations.

    PubMed

    Devos, Yann; Meihls, Lisa N; Kiss, József; Hibbard, Bruce E

    2013-04-01

    Western corn rootworm (Diabrotica virgifera virgifera; WCR) is a major coleopteran maize pest in North America and the EU, and has traditionally been managed through crop rotation and broad-spectrum soil insecticides. Genetically modified Bt-maize offers an additional management tool for WCR and has been valuable in reducing insecticide use and increasing farm income. A concern is that the widespread, repeated, and exclusive deployment of the same Bt-maize transformation event will result in the rapid evolution of resistance in WCR. This publication explores the potential of WCR to evolve resistance to plant-produced Bt-toxins from the first generation of Diabrotica-active Bt-maize events (MON 863 and MON 88017, DAS-59122-7 and MIR604), and whether currently implemented risk management strategies to delay and monitor resistance evolution are appropriate. In twelve of the twelve artificial selection experiments reported, resistant WCR populations were yielded rapidly. Field-selected resistance of WCR to Cry3Bb1 is documented in some US maize growing areas, where an increasing number of cases of unexpected damage of WCR larvae to Bt-maize MON 88017 has been reported. Currently implemented insect resistance management measures for Bt-crops usually rely on the high dose/refuge (HDR) strategy. Evidence (including laboratory, greenhouse and field data) indicates that several conditions contributing to the success of the HDR strategy may not be met for the first generation of Bt-maize events and WCR: (1) the Bt-toxins are expressed heterogeneously at a low-to-moderate dose in roots; (2) resistance alleles may be present at a higher frequency than initially assumed; (3) WCR may mate in a non-random manner; (4) resistance traits could have non-recessive inheritance; and (5) fitness costs may not necessarily be associated with resistance evolution. However, caution must be exercised when extrapolating laboratory and greenhouse results to field conditions. Model predictions

  19. Environmental impact of herbicide regimes used with genetically modified herbicide-resistant maize.

    PubMed

    Devos, Yann; Cougnon, Mathias; Vergucht, Sofie; Bulcke, Robert; Haesaert, Geert; Steurbaut, Walter; Reheul, Dirk

    2008-12-01

    With the potential advent of genetically modified herbicide-resistant (GMHR) crops in the European Union, changes in patterns of herbicide use are predicted. Broad-spectrum, non-selective herbicides used with GMHR crops are expected to substitute for a set of currently used herbicides, which might alter the agro-environmental footprint from crop production. To test this hypothesis, the environmental impact of various herbicide regimes currently used with non-GMHR maize in Belgium was calculated and compared with that of possible herbicide regimes applied in GMHR maize. Impacts on human health and the environment were calculated through the pesticide occupational and environmental risk (POCER) indicator. Results showed that the environmental impact of herbicide regimes solely relying on the active ingredients glyphosate (GLY) or glufosinate-ammonium (GLU) is lower than that of herbicide regimes applied in non-GMHR maize. Due to the lower potential of GLY and GLU to contaminate ground water and their lower acute toxicity to aquatic organisms, the POCER exceedence factor values for the environment were reduced approximately by a sixth when GLY or GLU is used alone. However, the environmental impact of novel herbicide regimes tested may be underestimated due to the assumption that active ingredients used with GMHR maize would be used alone. Data retrieved from literature suggest that weed control efficacy is increased and resistance development delayed when GLY or GLU is used together with other herbicides in the GMHR system. Due to the partial instead of complete replacement of currently used herbicide regimes, the beneficial environmental impact of novel herbicide regimes might sometimes be reduced or counterbalanced. Despite the high weed control efficacy provided by the biotechnology-based weed management strategy, neither indirect harmful effects on farmland biodiversity through losses in food resources and shelter, nor shifts in weed communities have been

  20. Genome-Wide Identification, Evolution and Expression Analysis of mTERF Gene Family in Maize

    PubMed Central

    Zhao, Yanxin; Cai, Manjun; Zhang, Xiaobo; Li, Yurong; Zhang, Jianhua; Zhao, Hailiang; Kong, Fei; Zheng, Yonglian; Qiu, Fazhan

    2014-01-01

    Plant mitochondrial transcription termination factor (mTERF) genes comprise a large family with important roles in regulating organelle gene expression. In this study, a comprehensive database search yielded 31 potential mTERF genes in maize (Zea mays L.) and most of them were targeted to mitochondria or chloroplasts. Maize mTERF were divided into nine main groups based on phylogenetic analysis, and group IX represented the mitochondria and species-specific clade that diverged from other groups. Tandem and segmental duplication both contributed to the expansion of the mTERF gene family in the maize genome. Comprehensive expression analysis of these genes, using microarray data and RNA-seq data, revealed that these genes exhibit a variety of expression patterns. Environmental stimulus experiments revealed differential up or down-regulation expression of maize mTERF genes in seedlings exposed to light/dark, salts and plant hormones, respectively, suggesting various important roles of maize mTERF genes in light acclimation and stress-related responses. These results will be useful for elucidating the roles of mTERF genes in the growth, development and stress response of maize. PMID:24718683

  1. Gene Expression and Chromatin Modifications Associated with Maize Centromeres

    PubMed Central

    Zhao, Hainan; Zhu, Xiaobiao; Wang, Kai; Gent, Jonathan I.; Zhang, Wenli; Dawe, R. Kelly; Jiang, Jiming

    2015-01-01

    Centromeres are defined by the presence of CENH3, a variant of histone H3. Centromeres in most plant species contain exclusively highly repetitive DNA sequences, which has hindered research on structure and function of centromeric chromatin. Several maize centromeres have been nearly completely sequenced, providing a sequence-based platform for genomic and epigenomic research of plant centromeres. Here we report a high resolution map of CENH3 nucleosomes in the maize genome. Although CENH3 nucleosomes are spaced ∼190 bp on average, CENH3 nucleosomes that occupied CentC, a 156-bp centromeric satellite repeat, showed clear positioning aligning with CentC monomers. Maize centromeres contain alternating CENH3-enriched and CENH3-depleted subdomains, which account for 87% and 13% of the centromeres, respectively. A number of annotated genes were identified in the centromeres, including 11 active genes that were located exclusively in CENH3-depleted subdomains. The euchromatic histone modification marks, including H3K4me3, H3K36me3 and H3K9ac, detected in maize centromeres were associated mainly with the active genes. Interestingly, maize centromeres also have lower levels of the heterochromatin histone modification mark H3K27me2 relative to pericentromeric regions. We conclude that neither H3K27me2 nor the three euchromatic histone modifications are likely to serve as functionally important epigenetic marks of centromere identity in maize. PMID:26564952

  2. Lack of repeatable differential expression patterns between MON810 and comparable commercial varieties of maize.

    PubMed

    Coll, Anna; Nadal, Anna; Palaudelmàs, Montserrat; Messeguer, Joaquima; Melé, Enric; Puigdomènech, Pere; Pla, Maria

    2008-09-01

    The introduction of genetically modified organisms (GMO) in many countries follows strict regulations to assure that only products that have been safety tested in relation to human health and the environment are marketed. Thus, GMOs must be authorized before use. By complementing more targeted approaches, profiling methods can assess possible unintended effects of transformation. We used microarrays to compare the transcriptome profiles of widely commercialized maize MON810 varieties and their non-GM near-isogenic counterparts. The expression profiles of MON810 seedlings are more similar to those of their corresponding near-isogenic varieties than are the profiles of other lines produced by conventional breeding. However, differential expression of approximately 1.7 and approximately 0.1% of transcripts was identified in two variety pairs (AristisBt/Aristis and PR33P67/PR33P66) that had similar cryIA(b) mRNA levels, demonstrating that commercial varieties of the same event have different similarity levels to their near-isogenic counterparts without the transgene (note that these two pairs also show phenotypic differences). In the tissues, developmental stage and varieties analyzed, we could not identify any gene differentially expressed in all variety-pairs. However, a small set of sequences were differentially expressed in various pairs. Their relation to the transgenesis was not proven, although this is likely to be modulated by the genetic background of each variety. PMID:18604604

  3. Transgenic maize lines with cell-type specific expression of fluorescent proteins in plastids.

    PubMed

    Sattarzadeh, Amir; Fuller, Jonathan; Moguel, Salvador; Wostrikoff, Katia; Sato, Shirley; Covshoff, Sarah; Clemente, Tom; Hanson, Maureen; Stern, David B

    2010-02-01

    Plastid number and morphology vary dramatically between cell types and at different developmental stages. Furthermore, in C4 plants such as maize, chloroplast ultrastructure and biochemical functions are specialized in mesophyll and bundle sheath cells, which differentiate acropetally from the proplastid form in the leaf base. To develop visible markers for maize plastids, we have created a series of stable transgenics expressing fluorescent proteins fused to either the maize ubiquitin promoter, the mesophyll-specific phosphoenolpyruvate carboxylase (PepC) promoter, or the bundle sheath-specific Rubisco small subunit 1 (RbcS) promoter. Multiple independent events were examined and revealed that maize codon-optimized versions of YFP and GFP were particularly well expressed, and that expression was stably inherited. Plants carrying PepC promoter constructs exhibit YFP expression in mesophyll plastids and the RbcS promoter mediated expression in bundle sheath plastids. The PepC and RbcS promoter fusions also proved useful for identifying plastids in organs such as epidermis, silks, roots and trichomes. These tools will inform future plastid-related studies of wild-type and mutant maize plants and provide material from which different plastid types may be isolated. PMID:20051034

  4. EXPRESSION OF THE MAIZE MOSAIC VIRUS GLYCOPROTEIN IN INSECT CELLS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize mosaic virus (genus Nucleorhabdovirus, family Rhabdoviridae) is transmitted in a persistent-propagative manner by Peregrinus maidis, the corn planthopper. Like other rhabdoviruses, the MMV genome encodes a surface glycoprotein that is likely involved in virus attachment and entry into host ce...

  5. Statistical modeling of correlatively expressed functional amino acids in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Modern maize breeding and selection for large starchy kernels may have contributed to reduced contents of essential amino acids which represents a serious nutritional problem for humans and animals. A large number (1,348) of germplasm accessions belonging to 13 populations and classified into four h...

  6. Identification and characterization of promoters specifically and strongly expressed in maize embryos.

    PubMed

    Liu, Xiaoqing; Tian, Jian; Zhou, Xiaojin; Chen, Rumei; Wang, Lei; Zhang, Chunyi; Zhao, Jun; Fan, Yunliu

    2014-12-01

    The use of maize seeds as bioreactors has several advantages for the production of recombinant proteins in plant biotechnology, but available embryo-specific and strong promoters are limited. Here, we describe a genome-scale microarray-based approach to identify embryo-specifically and strongly expressed genes and their promoters in maize. We identified 28 embryo-preferred and abundantly expressed genes based on our microarray data. These embryo-preferred genes were further analysed using the UniGene database and by quantitative reverse transcriptase-PCR leading to the identification of seven genes (Zm.2098, Zm.13387, Zm.66589, Zm.85502, Zm.68129, Zm.3896 and Zm.2941) as embryo-specific genes with higher expression levels relative to maize globulin-1. The putative promoters of five embryo-specific genes (Zm.13387, Zm.66589, Zm.85502, Zm.3896 and Zm.2941) were isolated and all exhibited strong promoter activities when transiently expressed in maize embryos of 20 DAP. The embryo specificity and expression levels of the promoters of four genes (Zm.13387, Zm.85502, Zm.3896 and Zm.2941) were further examined in transgenic maize plants, revealing that they are strong promoters in embryos of all four developmental stages tested compared with reference globulin-1 promoter. Moreover, Zm.2941 and Zm.3896 promoters are stringently embryo-specific promoters, while Zm.85502 promoter is basically embryo specific yet wounding inducible in non-seed tissues, and Zm.13387 promoter is developmentally expressed in both embryo and aleurone with wounding-induced activity in non-seed tissues. Our study provides novel embryo-specific and strong promoters that are suitable for production of high-level recombinant proteins in maize embryos. PMID:25052028

  7. Identification and characterization of paternal-preferentially expressed gene NF-YC8 in maize endosperm.

    PubMed

    Mei, Xiupeng; Liu, Chaoxian; Yu, Tingting; Liu, Xiaoli; Xu, De; Wang, Jiuguang; Wang, Guoqiang; Cai, Yilin

    2015-10-01

    Gene imprinting describes an epigenetic phenomenon, whereby genetically identical alleles are differentially expressed dependent on parent-of-origin. Some imprinted genes belonged to NUCLEAR FACTOR Y (NF-Y) transcription factors, which were involved in many important metabolic processes in plant. The characterizations of imprinted genes are of great importance for their function exploration. In this paper, 15 non-redundant NF-YC genes were identified in the maize genome and the paternally expressed gene NF-YC8 was further analyzed. NF-YC8 primarily expressed in maize immature ear and tassel and phylogenetic analysis showed that NF-YC8 was highly homologous with Arabidopsis thaliana NF-YC2 genes which function in regulation of the flowering processes, ER stress response. Furthermore, NF-YC8 was a differential, gene-specific imprinted gene at 14 DAP and persistently imprinted throughout later endosperm development in the B73/Mo17 genetic background. Bisulfite sequencing for NF-YC8 in maize endosperm showed that the paternal alleles were higher methylated (CG, CHG and CHH contexts) than maternal alleles in the 5' upstream region, and the coding region was highly methylated in CG context. Additionally, TE (CG, CHG and CHH contexts) and repetitive region (CG and CHG contexts) were all highly methylated. These results are the first description of evolution and molecular characterization of maize NF-YC8 and will provide new references for maize NF-YC genetic analysis. PMID:25851237

  8. Tissue-specific gene expression in maize seeds during colonization by Aspergillus flavus and Fusarium verticillioides.

    PubMed

    Shu, Xiaomei; Livingston, David P; Franks, Robert G; Boston, Rebecca S; Woloshuk, Charles P; Payne, Gary A

    2015-09-01

    Aspergillus flavus and Fusarium verticillioides are fungal pathogens that colonize maize kernels and produce the harmful mycotoxins aflatoxin and fumonisin, respectively. Management practice based on potential host resistance to reduce contamination by these mycotoxins has proven difficult, resulting in the need for a better understanding of the infection process by these fungi and the response of maize seeds to infection. In this study, we followed the colonization of seeds by histological methods and the transcriptional changes of two maize defence-related genes in specific seed tissues by RNA in situ hybridization. Maize kernels were inoculated with either A. flavus or F. verticillioides 21-22 days after pollination, and harvested at 4, 12, 24, 48, 72, 96 and 120 h post-inoculation. The fungi colonized all tissues of maize seed, but differed in their interactions with aleurone and germ tissues. RNA in situ hybridization showed the induction of the maize pathogenesis-related protein, maize seed (PRms) gene in the aleurone and scutellum on infection by either fungus. Transcripts of the maize sucrose synthase-encoding gene, shrunken-1 (Sh1), were observed in the embryo of non-infected kernels, but were induced on infection by each fungus in the aleurone and scutellum. By comparing histological and RNA in situ hybridization results from adjacent serial sections, we found that the transcripts of these two genes accumulated in tissue prior to the arrival of the advancing pathogens in the seeds. A knowledge of the patterns of colonization and tissue-specific gene expression in response to these fungi will be helpful in the development of resistance. PMID:25469958

  9. 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. PMID:24962048

  10. A mathematical model of exposure of non-target Lepidoptera to Bt-maize pollen expressing Cry1Ab within Europe

    PubMed Central

    Perry, J. N.; Devos, Y.; Arpaia, S.; Bartsch, D.; Gathmann, A.; Hails, R. S.; Kiss, J.; Lheureux, K.; Manachini, B.; Mestdagh, S.; Neemann, G.; Ortego, F.; Schiemann, J.; Sweet, J. B.

    2010-01-01

    Genetically modified (GM) maize MON810 expresses a Cry1Ab insecticidal protein, derived from Bacillus thuringiensis (Bt), toxic to lepidopteran target pests such as Ostrinia nubilalis. An environmental risk to non-target Lepidoptera from this GM crop is exposure to harmful amounts of Bt-containing pollen deposited on host plants in or near MON810 fields. An 11-parameter mathematical model analysed exposure of larvae of three non-target species: the butterflies Inachis io (L.), Vanessa atalanta (L.) and moth Plutella xylostella (L.), in 11 representative maize cultivation regions in four European countries. A mortality–dose relationship was integrated with a dose–distance relationship to estimate mortality both within the maize MON810 crop and within the field margin at varying distances from the crop edge. Mortality estimates were adjusted to allow for physical effects; the lack of temporal coincidence between the susceptible larval stage concerned and the period over which maize MON810 pollen is shed; and seven further parameters concerned with maize agronomy and host-plant ecology. Sublethal effects were estimated and allowance made for aggregated pollen deposition. Estimated environmental impact was low: in all regions, the calculated mortality rate for worst-case scenarios was less than one individual in every 1572 for the butterflies and one in 392 for the moth. PMID:20053648

  11. Expression of defense-related genes in maize developing kernels in late stages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We analyzed temporal patterns of gene expression profiles in developing kernels of Tex6, reported to have reduced aflatoxin contamination, at 25, 30, 35, 40 and 45 days after pollination (DAP) using maize oligonuleotide microarray. There was a total of 57,452 70-mer oligonucleotides on the array. Th...

  12. The ethylene biosynthetic and perception machinery is differentially expressed during endosperm and embryo development in maize.

    PubMed

    Gallie, D R; Young, T E

    2004-04-01

    The maize endosperm undergoes programmed cell death late in its development so that, with the exception of the aleurone layer, the tissue is dead by the time the kernel matures. Although ethylene is known to regulate the onset of endosperm cell death, the temporal and spatial control of the ethylene biosynthetic and perception machinery during maize endosperm development has not been examined. In this study, we report the isolation of the maize gene families for ACC synthase, ACC oxidase, the ethylene receptor, and EIN2 and EIL, which act downstream of the receptor. We show that ACC oxidase is expressed primarily in the endosperm, and only at low levels in the developing embryo late in its development. ACC synthase is expressed throughout endosperm development but, in contrast to ACC oxidase, it is transiently expressed to a significantly higher level in the developing embryo at a time that corresponds with the onset of endosperm cell death. Only two ethylene receptor gene families were identified in maize, in contrast to the five types previously identified in Arabidopsis. Members of both ethylene receptor families were expressed to substantially higher levels in the developing embryo than in the endosperm, as were members of the EIN2 and EIL gene families. These results suggest that the endosperm and embryo both contribute to the synthesis of ethylene, and they provide a basis for understanding why the developing endosperm is especially sensitive to ethylene-induced cell death while the embryo is protected. PMID:14760521

  13. Challenges in testing genetically modified crops for potential increases in endogenous allergen expression for safety.

    PubMed

    Panda, R; Ariyarathna, H; Amnuaycheewa, P; Tetteh, A; Pramod, S N; Taylor, S L; Ballmer-Weber, B K; Goodman, R E

    2013-02-01

    Premarket, genetically modified (GM) plants are assessed for potential risks of food allergy. The major risk would be transfer of a gene encoding an allergen or protein nearly identical to an allergen into a different food source, which can be assessed by specific serum testing. The potential that a newly expressed protein might become an allergen is evaluated based on resistance to digestion in pepsin and abundance in food fractions. If the modified plant is a common allergenic source (e.g. soybean), regulatory guidelines suggest testing for increases in the expression of endogenous allergens. Some regulators request evaluating endogenous allergens for rarely allergenic plants (e.g. maize and rice). Since allergic individuals must avoid foods containing their allergen (e.g. peanut, soybean, maize, or rice), the relevance of the tests is unclear. Furthermore, no acceptance criteria are established and little is known about the natural variation in allergen concentrations in these crops. Our results demonstrate a 15-fold difference in the major maize allergen, lipid transfer protein between nine varieties, and complex variation in IgE binding to various soybean varieties. We question the value of evaluating endogenous allergens in GM plants unless the intent of the modification was production of a hypoallergenic crop. PMID:23205714

  14. Resistance evolution to the first generation of genetically modified Diabrotica-active Bt-maize events by western corn rootworm: management and monitoring considerations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Western corn rootworm (Diabrotica virgifera virgifera; WCR) is a major coleopteran maize pest in North America and the EU, and has traditionally been managed through crop rotation and broad-spectrum soil insecticides. Genetically modified (GM) Bt-maize offers an additional means of control against W...

  15. Gene expression analyses in maize inbreds and hybrids with varying levels of heterosis

    PubMed Central

    Stupar, Robert M; Gardiner, Jack M; Oldre, Aaron G; Haun, William J; Chandler, Vicki L; Springer, Nathan M

    2008-01-01

    Background Heterosis is the superior performance of F1 hybrid progeny relative to the parental phenotypes. Maize exhibits heterosis for a wide range of traits, however the magnitude of heterosis is highly variable depending on the choice of parents and the trait(s) measured. We have used expression profiling to determine whether the level, or types, of non-additive gene expression vary in maize hybrids with different levels of genetic diversity or heterosis. Results We observed that the distributions of better parent heterosis among a series of 25 maize hybrids generally do not exhibit significant correlations between different traits. Expression profiling analyses for six of these hybrids, chosen to represent diversity in genotypes and heterosis responses, revealed a correlation between genetic diversity and transcriptional variation. The majority of differentially expressed genes in each of the six different hybrids exhibited additive expression patterns, and ~25% exhibited statistically significant non-additive expression profiles. Among the non-additive profiles, ~80% exhibited hybrid expression levels between the parental levels, ~20% exhibited hybrid expression levels at the parental levels and ~1% exhibited hybrid levels outside the parental range. Conclusion We have found that maize inbred genetic diversity is correlated with transcriptional variation. However, sampling of seedling tissues indicated that the frequencies of additive and non-additive expression patterns are very similar across a range of hybrid lines. These findings suggest that heterosis is probably not a consequence of higher levels of additive or non-additive expression, but may be related to transcriptional variation between parents. The lack of correlation between better parent heterosis levels for different traits suggests that transcriptional diversity at specific sets of genes may influence heterosis for different traits. PMID:18402703

  16. Establishment of Quantitative Analysis Method for Genetically Modified Maize Using a Reference Plasmid and Novel Primers

    PubMed Central

    Moon, Gi-Seong; Shin, Weon-Sun

    2012-01-01

    For the quantitative analysis of genetically modified (GM) maize in processed foods, primer sets and probes based on the 35S promoter (p35S), nopaline synthase terminator (tNOS), p35S-hsp70 intron, and zSSIIb gene encoding starch synthase II for intrinsic control were designed. Polymerase chain reaction (PCR) products (80~101 bp) were specifically amplified and the primer sets targeting the smaller regions (80 or 81 bp) were more sensitive than those targeting the larger regions (94 or 101 bp). Particularly, the primer set 35F1-R1 for p35S targeting 81 bp of sequence was even more sensitive than that targeting 101 bp of sequence by a 3-log scale. The target DNA fragments were also specifically amplified from all GM labeled food samples except for one item we tested when 35F1-R1 primer set was applied. A reference plasmid pGMmaize (3 kb) including the smaller PCR products for p35S, tNOS, p35S-hsp70 intron, and the zSSIIb gene was constructed for real-time PCR (RT-PCR). The linearity of standard curves was confirmed by using diluents ranging from 2×101~105 copies of pGMmaize and the R2 values ranged from 0.999~1.000. In the RT-PCR, the detection limit using the novel primer/probe sets was 5 pg of genomic DNA from MON810 line indicating that the primer sets targeting the smaller regions (80 or 81 bp) could be used for highly sensitive detection of foreign DNA fragments from GM maize in processed foods. PMID:24471096

  17. Detection of airborne genetically modified maize pollen by real-time PCR.

    PubMed

    Folloni, Silvia; Kagkli, Dafni-Maria; Rajcevic, Bojan; Guimarães, Nilson C C; Van Droogenbroeck, Bart; Valicente, Fernando H; Van den Eede, Guy; Van den Bulcke, Marc

    2012-09-01

    The cultivation of genetically modified (GM) crops has raised numerous concerns in the European Union and other parts of the world about their environmental and economic impact. Especially outcrossing of genetically modified organisms (GMO) was from the beginning a critical issue as airborne pollen has been considered an important way of GMO dispersal. Here, we investigate the use of airborne pollen sampling combined with microscopic analysis and molecular PCR analysis as an approach to monitor GM maize cultivations in a specific area. Field trial experiments in the European Union and South America demonstrated the applicability of the approach under different climate conditions, in rural and semi-urban environment, even at very low levels of airborne pollen. The study documents in detail the sampling of GM pollen, sample DNA extraction and real-time PCR analysis. Our results suggest that this 'GM pollen monitoring by bioaerosol sampling and PCR screening' approach might represent an useful aid in the surveillance of GM-free areas, centres of origin and natural reserves. PMID:22805239

  18. Active maize genes are unmodified and flanked by diverse classes of modified, highly repetitive DNA.

    PubMed

    Bennetzen, J L; Schrick, K; Springer, P S; Brown, W E; SanMiguel, P

    1994-08-01

    We have characterized the copy number, organization, and genomic modification of DNA sequences within and flanking several maize genes. We found that highly repetitive DNA sequences were tightly linked to most of these genes. The highly repetitive sequences were not found within the coding regions but could be found within 6 kb either 3' or 5' to the structural genes. These highly repetitive regions were each composed of unique combinations of different short repetitive sequences. Highly repetitive DNA blocks were not interrupted by any detected single copy DNA. The 13 classes of highly repetitive DNA identified were found to vary little between diverse Zea isolates. The level of DNA methylation in and near these genes was determined by scoring the digestibility of 63 recognition/cleavage sites with restriction enzymes that were sensitive to 5-methylation of cytosines in the sequences 5'-CG-3' and 5'-CNG-3'. All but four of these sites were digestible in chromosomal DNA. The four undigested sites were localized to extragenic DNA within or near highly repetitive DNA, while the other 59 sites were in low copy number DNAs. Pulsed field gel analysis indicated that the majority of cytosine modified tracts range from 20 to 200 kb in size. Single copy sequences hybridized to the unmodified domains, while highly repetitive sequences hybridized to the modified regions. Middle repetitive sequences were found in both domains. PMID:7958822

  19. Long term toxicity of a Roundup herbicide and a Roundup-tolerant genetically modified maize.

    PubMed

    Séralini, Gilles-Eric; Clair, Emilie; Mesnage, Robin; Gress, Steeve; Defarge, Nicolas; Malatesta, Manuela; Hennequin, Didier; de Vendômois, Joël Spiroux

    2012-11-01

    The health effects of a Roundup-tolerant genetically modified maize (from 11% in the diet), cultivated with or without Roundup, and Roundup alone (from 0.1 ppb in water), were studied 2 years in rats. In females, all treated groups died 2-3 times more than controls, and more rapidly. This difference was visible in 3 male groups fed GMOs. All results were hormone and sex dependent, and the pathological profiles were comparable. Females developed large mammary tumors almost always more often than and before controls, the pituitary was the second most disabled organ; the sex hormonal balance was modified by GMO and Roundup treatments. In treated males, liver congestions and necrosis were 2.5-5.5 times higher. This pathology was confirmed by optic and transmission electron microscopy. Marked and severe kidney nephropathies were also generally 1.3-2.3 greater. Males presented 4 times more large palpable tumors than controls which occurred up to 600 days earlier. Biochemistry data confirmed very significant kidney chronic deficiencies; for all treatments and both sexes, 76% of the altered parameters were kidney related. These results can be explained by the non linear endocrine-disrupting effects of Roundup, but also by the overexpression of the transgene in the GMO and its metabolic consequences. PMID:22999595

  20. The maize unstable factor for orange1 is a dominant epigenetic modifier of a tissue specifically silent allele of pericarp color1.

    PubMed Central

    Chopra, Surinder; Cocciolone, Suzy M; Bushman, Shaun; Sangar, Vineet; McMullen, Michael D; Peterson, Thomas

    2003-01-01

    We have characterized Unstable factor for orange1 (Ufo1), a dominant, allele-specific modifier of expression of the maize pericarp color1 (p1) gene. The p1 gene encodes an Myb-homologous transcriptional activator of genes required for biosynthesis of red phlobaphene pigments. The P1-wr allele specifies colorless kernel pericarp and red cobs, whereas Ufo1 modifies P1-wr expression to confer pigmentation in kernel pericarp, as well as vegetative tissues, which normally do not accumulate significant amounts of phlobaphene pigments. In the presence of Ufo1, P1-wr transcript levels and transcription rate are increased in kernel pericarp. The P1-wr allele contains approximately six p1 gene copies present in a hypermethylated and multicopy tandem array. In P1-wr Ufo1 plants, methylation of P1-wr DNA sequences is reduced, whereas the methylation state of other repetitive genomic sequences was not detectably affected. The phenotypes produced by the interaction of P1-wr and Ufo1 are unstable, exhibiting somatic mosaicism and variable penetrance. Moreover, the changes in P1-wr expression and methylation are not heritable: meiotic segregants that lack Ufo1 revert to the normal P1-wr expression and methylation patterns. These results demonstrate the existence of a class of modifiers of gene expression whose effects are associated with transient changes in DNA methylation of specific loci. PMID:12663550

  1. Genotypic and Environmental Impact on Natural Variation of Nutrient Composition in 50 Non Genetically Modified Commercial Maize Hybrids in North America.

    PubMed

    Cong, Bin; Maxwell, Carl; Luck, Stanley; Vespestad, Deanne; Richard, Keith; Mickelson, James; Zhong, Cathy

    2015-06-10

    This study was designed to assess natural variation in composition and metabolites in 50 genetically diverse non genetically modified maize hybrids grown at six locations in North America. Results showed that levels of compositional components in maize forage were affected by environment more than genotype. Crude protein, all amino acids except lysine, manganese, and β-carotene in maize grain were affected by environment more than genotype; however, most proximates and fibers, all fatty acids, lysine, most minerals, vitamins, and secondary metabolites in maize grain were affected by genotype more than environment. A strong interaction between genotype and environment was seen for some analytes. The results could be used as reference values for future nutrient composition studies of genetically modified crops and to expand conventional compositional data sets. These results may be further used as a genetic basis for improvement of the nutritional value of maize grain by molecular breeding and biotechnology approaches. PMID:25971869

  2. First application of a microsphere-based immunoassay to the detection of genetically modified organisms (GMOs): quantification of Cry1Ab protein in genetically modified maize.

    PubMed

    Fantozzi, Anna; Ermolli, Monica; Marini, Massimiliano; Scotti, Domenico; Balla, Branko; Querci, Maddalena; Langrell, Stephen R H; Van den Eede, Guy

    2007-02-21

    An innovative covalent microsphere immunoassay, based on the usage of fluorescent beads coupled to a specific antibody, was developed for the quantification of the endotoxin Cry1Ab present in MON810 and Bt11 genetically modified (GM) maize lines. In particular, a specific protocol was developed to assess the presence of Cry1Ab in a very broad range of GM maize concentrations, from 0.1 to 100% [weight of genetically modified organism (GMO)/weight]. Test linearity was achieved in the range of values from 0.1 to 3%, whereas fluorescence signal increased following a nonlinear model, reaching a plateau at 25%. The limits of detection and quantification were equal to 0.018 and 0.054%, respectively. The present study describes the first application of quantitative high-throughput immunoassays in GMO analysis. PMID:17300145

  3. Enhanced water stress tolerance of transgenic maize plants over-expressing LEA Rab28 gene.

    PubMed

    Amara, Imen; Capellades, Montserrat; Ludevid, M Dolors; Pagès, Montserrat; Goday, Adela

    2013-06-15

    Late Embryogenesis Abundant (LEA) proteins participate in plant stress responses and contribute to the acquisition of desiccation tolerance. In this report Rab28 LEA gene has been over-expressed in maize plants under a constitutive maize promoter. The expression of Rab28 transcripts led to the accumulation and stability of Rab28 protein in the transgenic plants. Native Rab28 protein is localized to nucleoli in wild type maize embryo cells; here we find by whole-mount immunocytochemistry that in root cells of Rab28 transgenic and wild-type plants the protein is also associated to nucleolar structures. Transgenic plants were tested for stress tolerance and resulted in sustained growth under polyethyleneglycol (PEG)-mediated dehydration compared to wild-type controls. Under osmotic stress transgenic seedlings showed increased leaf and root areas, higher relative water content (RWC), reduced chlorophyll loss and lower Malondialdehyde (MDA) production in relation to wild-type plants. Moreover, transgenic seeds exhibited higher germination rates than wild-type seeds under water deficit. Overall, our results highlight the presence of transgenic Rab28 protein in nucleolar structures and point to the potential of group 5 LEA Rab28 gene as candidate to enhance stress tolerance in maize plants. PMID:23384757

  4. Genome-Wide Identification, Characterization and Expression Analysis of the Chalcone Synthase Family in Maize

    PubMed Central

    Han, Yahui; Ding, Ting; Su, Bo; Jiang, Haiyang

    2016-01-01

    Members of the chalcone synthase (CHS) family participate in the synthesis of a series of secondary metabolites in plants, fungi and bacteria. The metabolites play important roles in protecting land plants against various environmental stresses during the evolutionary process. Our research was conducted on comprehensive investigation of CHS genes in maize (Zea mays L.), including their phylogenetic relationships, gene structures, chromosomal locations and expression analysis. Fourteen CHS genes (ZmCHS01–14) were identified in the genome of maize, representing one of the largest numbers of CHS family members identified in one organism to date. The gene family was classified into four major classes (classes I–IV) based on their phylogenetic relationships. Most of them contained two exons and one intron. The 14 genes were unevenly located on six chromosomes. Two segmental duplication events were identified, which might contribute to the expansion of the maize CHS gene family to some extent. In addition, quantitative real-time PCR and microarray data analyses suggested that ZmCHS genes exhibited various expression patterns, indicating functional diversification of the ZmCHS genes. Our results will contribute to future studies of the complexity of the CHS gene family in maize and provide valuable information for the systematic analysis of the functions of the CHS gene family. PMID:26828478

  5. Genome-Wide Identification, Characterization and Expression Analysis of the Chalcone Synthase Family in Maize.

    PubMed

    Han, Yahui; Ding, Ting; Su, Bo; Jiang, Haiyang

    2016-01-01

    Members of the chalcone synthase (CHS) family participate in the synthesis of a series of secondary metabolites in plants, fungi and bacteria. The metabolites play important roles in protecting land plants against various environmental stresses during the evolutionary process. Our research was conducted on comprehensive investigation of CHS genes in maize (Zea mays L.), including their phylogenetic relationships, gene structures, chromosomal locations and expression analysis. Fourteen CHS genes (ZmCHS01-14) were identified in the genome of maize, representing one of the largest numbers of CHS family members identified in one organism to date. The gene family was classified into four major classes (classes I-IV) based on their phylogenetic relationships. Most of them contained two exons and one intron. The 14 genes were unevenly located on six chromosomes. Two segmental duplication events were identified, which might contribute to the expansion of the maize CHS gene family to some extent. In addition, quantitative real-time PCR and microarray data analyses suggested that ZmCHS genes exhibited various expression patterns, indicating functional diversification of the ZmCHS genes. Our results will contribute to future studies of the complexity of the CHS gene family in maize and provide valuable information for the systematic analysis of the functions of the CHS gene family. PMID:26828478

  6. Relationship among physiological quality, heterosis, and amylase gene expression in maize seeds.

    PubMed

    Oliveira, G E; Von Pinho, E V R; Andrade, T; Souza, J C; Caixeta, F; Ferreira, R A D C

    2015-01-01

    In this study, we analyzed heterosis, amylase enzyme gene expression, and the physiological quality of maize seeds with different genotypes and sizes, which were subjected to aging and not subjected to aging. We used seeds from 2 maize lines that differed with regard to physiological quality, the hybrid, and the reciprocal hybrid; they were classified into 2 sizes and were subjected to aging and not subjected to aging. Physiological quality was assessed by performing tests for germination, emergence, emergence speed index, and artificial aging. Expressions of the genes alpha amylase B73, alpha amylase (LOC542522), isoamylase mRNA clone 353244, and the endogenous controls ubiquitin and alcohol dehydrogenase in the seeds were studied using quantitative real-time-polymerase chain reaction. We observed heterosis for seed quality and for expression of amylase genes in the genotypes studied. We found no difference in seed quality between large and small seeds. PMID:26345793

  7. Expression of a Truncated ATHB17 Protein in Maize Increases Ear Weight at Silking

    PubMed Central

    Creelman, Robert A.; Griffith, Cara; Ahrens, Jeffrey E.; Taylor, J. Philip; Murphy, Lesley R.; Manjunath, Siva; Thompson, Rebecca L.; Lingard, Matthew J.; Back, Stephanie L.; Larue, Huachun; Brayton, Bonnie R.; Burek, Amanda J.; Tiwari, Shiv; Adam, Luc; Morrell, James A.; Caldo, Rico A.; Huai, Qing; Kouadio, Jean-Louis K.; Kuehn, Rosemarie; Sant, Anagha M.; Wingbermuehle, William J.; Sala, Rodrigo; Foster, Matt; Kinser, Josh D.; Mohanty, Radha; Jiang, Dongming; Ziegler, Todd E.; Huang, Mingya G.; Kuriakose, Saritha V.; Skottke, Kyle; Repetti, Peter P.; Reuber, T. Lynne; Ruff, Thomas G.; Petracek, Marie E.; Loida, Paul J.

    2014-01-01

    ATHB17 (AT2G01430) is an Arabidopsis gene encoding a member of the α-subclass of the homeodomain leucine zipper class II (HD-Zip II) family of transcription factors. The ATHB17 monomer contains four domains common to all class II HD-Zip proteins: a putative repression domain adjacent to a homeodomain, leucine zipper, and carboxy terminal domain. However, it also possesses a unique N-terminus not present in other members of the family. In this study we demonstrate that the unique 73 amino acid N-terminus is involved in regulation of cellular localization of ATHB17. The ATHB17 protein is shown to function as a transcriptional repressor and an EAR-like motif is identified within the putative repression domain of ATHB17. Transformation of maize with an ATHB17 expression construct leads to the expression of ATHB17Δ113, a truncated protein lacking the first 113 amino acids which encodes a significant portion of the repression domain. Because ATHB17Δ113 lacks the repression domain, the protein cannot directly affect the transcription of its target genes. ATHB17Δ113 can homodimerize, form heterodimers with maize endogenous HD-Zip II proteins, and bind to target DNA sequences; thus, ATHB17Δ113 may interfere with HD-Zip II mediated transcriptional activity via a dominant negative mechanism. We provide evidence that maize HD-Zip II proteins function as transcriptional repressors and that ATHB17Δ113 relieves this HD-Zip II mediated transcriptional repression activity. Expression of ATHB17Δ113 in maize leads to increased ear size at silking and, therefore, may enhance sink potential. We hypothesize that this phenotype could be a result of modulation of endogenous HD-Zip II pathways in maize. PMID:24736658

  8. Discovery and purification of a fungal protease secreted by Bipolaris zeicola that modifies maize seed endochitinase

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Healthy maize seeds have two basic endochitinases, chitA and chitB, with antifungal properties. A comparison of the isoenzyme profiles of symptomatic fungal-infested maize seeds, removed at harvest from ears that we wound inoculated in the late milk stage of maturity with one of several common ear-...

  9. Detection of six genetically modified maize lines using optical thin-film biosensor chips.

    PubMed

    Bai, Sulan; Zhang, Jie; Li, Shucheng; Chen, Haodong; Terzaghi, William; Zhang, Xin; Chi, Xiurong; Tian, Jin; Luo, Hongxia; Huang, Wensheng; Chen, Ying; Zhang, Yaochuan

    2010-08-11

    As more and more genetically modified organisms (GMO) are commercialized, efficient and inexpensive assays are required for their quick detection. An event-specific detection strategy based on the unique and specific sequences of integration junctions is useful because of its high specificity. This study developed a system for detecting six GM maize lines (Bt11, Bt176, GA21, MON810, NK603, and T25) using optical silicon thin-film biosensor chips. Aldehyde-labeled probes were arrayed and covalently attached to a hydrazine-derivatized chip surface. Biotinylated PCR amplicons were then hybridized with the probes. After washing and brief incubation with an anti-biotin IgG horseradish peroxidase conjugate and a precipitable horseradish peroxidase substrate, biotinylated PCR amplicons perfectly matched with the probes can be visualized by the color change on the chip surface (gold to blue/purple). This assay is extremely robust, exhibits high sensitivity and specificity, and is flexible from low through moderate to high throughput. PMID:20614904

  10. Short-term effects of different genetically modified maize varieties on arthropod food web properties: an experimental field assessment

    PubMed Central

    Szénási, Ágnes; Pálinkás, Zoltán; Zalai, Mihály; Schmitz, Oswald J.; Balog, Adalbert

    2014-01-01

    There is concern that genetically modified (GM) plants may have adverse affects on the arthropod biodiversity comprising agricultural landscapes. The present study report on a two year field experimental test of whether four different genotypic lines, some are novel with no previous field tests, of GM maize hybrids alter the structure of arthropod food webs that they harbour, relative to non-GM maize (control) that is widely used in agriculture. The different GM genotypes produced either Bt toxins, conferred glyphosate tolerance or a combination of the two traits. Quantitative food web analysis, based on short-term assessment assigning a total of 243,896 arthropod individuals collected from the treatments to their positions in food webs, revealed that complex and stable food webs persisted in each maize treatment. Moreover, food web structure remained relatively unchanged by the GM-genotype. The results suggest that at least in short-term period these particular GM maize genotypes will not have adverse effects on arthropod biota of agricultural landscapes. PMID:24937207

  11. Overexpression of ARGOS Genes Modifies Plant Sensitivity to Ethylene, Leading to Improved Drought Tolerance in Both Arabidopsis and Maize.

    PubMed

    Shi, Jinrui; Habben, Jeffrey E; Archibald, Rayeann L; Drummond, Bruce J; Chamberlin, Mark A; Williams, Robert W; Lafitte, H Renee; Weers, Ben P

    2015-09-01

    Lack of sufficient water is a major limiting factor to crop production worldwide, and the development of drought-tolerant germplasm is needed to improve crop productivity. The phytohormone ethylene modulates plant growth and development as well as plant response to abiotic stress. Recent research has shown that modifying ethylene biosynthesis and signaling can enhance plant drought tolerance. Here, we report novel negative regulators of ethylene signal transduction in Arabidopsis (Arabidopsis thaliana) and maize (Zea mays). These regulators are encoded by the ARGOS gene family. In Arabidopsis, overexpression of maize ARGOS1 (ZmARGOS1), ZmARGOS8, Arabidopsis ARGOS homolog ORGAN SIZE RELATED1 (AtOSR1), and AtOSR2 reduced plant sensitivity to ethylene, leading to enhanced drought tolerance. RNA profiling and genetic analysis suggested that the ZmARGOS1 transgene acts between an ethylene receptor and CONSTITUTIVE TRIPLE RESPONSE1 in the ethylene signaling pathway, affecting ethylene perception or the early stages of ethylene signaling. Overexpressed ZmARGOS1 is localized to the endoplasmic reticulum and Golgi membrane, where the ethylene receptors and the ethylene signaling protein ETHYLENE-INSENSITIVE2 and REVERSION-TO-ETHYLENE SENSITIVITY1 reside. In transgenic maize plants, overexpression of ARGOS genes also reduces ethylene sensitivity. Moreover, field testing showed that UBIQUITIN1:ZmARGOS8 maize events had a greater grain yield than nontransgenic controls under both drought stress and well-watered conditions. PMID:26220950

  12. Short-term effects of different genetically modified maize varieties on arthropod food web properties: an experimental field assessment.

    PubMed

    Szénási, Ágnes; Pálinkás, Zoltán; Zalai, Mihály; Schmitz, Oswald J; Balog, Adalbert

    2014-01-01

    There is concern that genetically modified (GM) plants may have adverse affects on the arthropod biodiversity comprising agricultural landscapes. The present study report on a two year field experimental test of whether four different genotypic lines, some are novel with no previous field tests, of GM maize hybrids alter the structure of arthropod food webs that they harbour, relative to non-GM maize (control) that is widely used in agriculture. The different GM genotypes produced either Bt toxins, conferred glyphosate tolerance or a combination of the two traits. Quantitative food web analysis, based on short-term assessment assigning a total of 243,896 arthropod individuals collected from the treatments to their positions in food webs, revealed that complex and stable food webs persisted in each maize treatment. Moreover, food web structure remained relatively unchanged by the GM-genotype. The results suggest that at least in short-term period these particular GM maize genotypes will not have adverse effects on arthropod biota of agricultural landscapes. PMID:24937207

  13. Expression and characterization of maize ZBP14, a member of a new family of zinc-binding proteins.

    PubMed Central

    Robinson, K; Jones, D; Howell, S; Soneji, Y; Martin, S; Aitken, A

    1995-01-01

    A maize gene (Mz2-12), with a deduced amino acid sequence similar to that of a protein kinase C (PKC) inhibitor from bovine brain, has been expressed in Escherichia coli and the protein (ZBP14) purified to homogeneity. The bovine protein was originally identified by Walsh's group and named PKC inhibitor-1 (PKCI-1). The recombinant maize protein (ZBP14) shares characteristics of bovine PKCI-1: it has similar secondary structure, is dimeric, and has a similar affinity for zinc. However, the maize ZBP14 had very little activity as an inhibitor of mammalian brain PKC, thus precluding zinc sequestration as the mechanism of inhibition. The biological role for the maize protein in plant kinase regulation is therefore unclear. In the presence of both maize ZBP14 and 14-3-3 protein (which inhibits PKC in the absence of diacylglycerol), the effects on PKC appeared to be synergistic. Images Figure 1 PMID:7717986

  14. Genome-wide identification, classification and expression profiling of nicotianamine synthase (NAS) gene family in maize

    PubMed Central

    2013-01-01

    Background Nicotianamine (NA), a ubiquitous molecule in plants, is an important metal ion chelator and the main precursor for phytosiderophores biosynthesis. Considerable progress has been achieved in cloning and characterizing the functions of nicotianamine synthase (NAS) in plants including barley, Arabidopsis and rice. Maize is not only an important cereal crop, but also a model plant for genetics and evolutionary study. The genome sequencing of maize was completed, and many gene families were identified. Although three NAS genes have been characterized in maize, there is still no systematic identification of maize NAS family by genomic mining. Results In this study, nine NAS genes in maize were identified and their expression patterns in different organs including developing seeds were determined. According to the evolutionary relationship and tissue specific expression profiles of ZmNAS genes, they can be subgrouped into two classes. Moreover, the expression patterns of ZmNAS genes in response to fluctuating metal status were analysed. The class I ZmNAS genes were induced under Fe deficiency and were suppressed under Fe excessive conditions, while the expression pattern of class II genes were opposite to class I. The complementary expression patterns of class I and class II ZmNAS genes confirmed the classification of this family. Furthermore, the histochemical localization of ZmNAS1;1/1;2 and ZmNAS3 were determined using in situ hybridization. It was revealed that ZmNAS1;1/1;2, representing the class I genes, mainly expressed in cortex and stele of roots with sufficient Fe, and its expression can expanded in epidermis, as well as shoot apices under Fe deficient conditions. On the contrary, ZmNAS3, one of the class II genes, was accumulated in axillary meristems, leaf primordia and mesophyll cells. These results suggest that the two classes of ZmNAS genes may be regulated on transcriptional level when responds to various demands for iron uptake, translocation

  15. Heterologous expression of cellobiohydrolase II (Cel6A) in maize endosperm.

    PubMed

    Devaiah, Shivakumar Pattada; Requesens, Deborah Vicuna; Chang, Yeun-Kyung; Hood, Kendall R; Flory, Ashley; Howard, John A; Hood, Elizabeth E

    2013-06-01

    The technology of converting lignocellulose to biofuels has advanced swiftly over the past few years, and enzymes are a significant constituent of this technology. In this regard, cost effective production of cellulases has been the focus of research for many years. One approach to reach cost targets of these enzymes involves the use of plants as bio-factories. The application of this technology to plant biomass conversion for biofuels and biobased products has the potential for significantly lowering the cost of these products due to lower enzyme production costs. Cel6A, one of the two cellobiohydrolases (CBH II) produced by Hypocrea jecorina, is an exoglucanase that cleaves primarily cellobiose units from the non-reducing end of cellulose microfibrils. In this work we describe the expression of Cel6A in maize endosperm as part of the process to lower the cost of this dominant enzyme for the bioconversion process. The enzyme is active on microcrystalline cellulose as exponential microbial growth was observed in the mixture of cellulose, cellulases, yeast and Cel6A, Cel7A (endoglucanase), and Cel5A (cellobiohydrolase I) expressed in maize seeds. We quantify the amount accumulated and the activity of the enzyme. Cel6A expressed in maize endosperm was purified to homogeneity and verified using peptide mass finger printing. PMID:23080294

  16. Global gene expression analysis of the shoot apical meristem of maize (Zea mays L.)

    PubMed Central

    Ohtsu, Kazuhiro; Smith, Marianne B; Emrich, Scott J; Borsuk, Lisa A; Zhou, Ruilian; Chen, Tianle; Zhang, Xiaolan; Timmermans, Marja C P; Beck, Jon; Buckner, Brent; Janick-Buckner, Diane; Nettleton, Dan; Scanlon, Michael J; Schnable, Patrick S

    2007-01-01

    All above-ground plant organs are derived from shoot apical meristems (SAMs). Global analyses of gene expression were conducted on maize (Zea mays L.) SAMs to identify genes preferentially expressed in the SAM. The SAMs were collected from 14-day-old B73 seedlings via laser capture microdissection (LCM). The RNA samples extracted from LCM-collected SAMs and from seedlings were hybridized to microarrays spotted with 37 660 maize cDNAs. Approximately 30% (10 816) of these cDNAs were prepared as part of this study from manually dissected B73 maize apices. Over 5000 expressed sequence tags (ESTs) (about 13% of the total) were differentially expressed (P<0.0001) between SAMs and seedlings. Of these, 2783 and 2248 ESTs were up- and down-regulated in the SAM, respectively. The expression in the SAM of several of the differentially expressed ESTs was validated via quantitative RT-PCR and/or in situ hybridization. The up-regulated ESTs included many regulatory genes including transcription factors, chromatin remodeling factors and components of the gene-silencing machinery, as well as about 900 genes with unknown functions. Surprisingly, transcripts that hybridized to 62 retrotransposon-related cDNAs were also substantially up-regulated in the SAM. Complementary DNAs derived from the LCM-collected SAMs were sequenced to identify additional genes that are expressed in the SAM. This generated around 550 000 ESTs (454-SAM ESTs) from two genotypes. Consistent with the microarray results, approximately 14% of the 454-SAM ESTs from B73 were retrotransposon-related. Possible roles of genes that are preferentially expressed in the SAM are discussed. PMID:17764504

  17. Nonsyntenic Genes Drive Tissue-Specific Dynamics of Differential, Nonadditive, and Allelic Expression Patterns in Maize Hybrids1[OPEN

    PubMed Central

    2016-01-01

    Distantly related maize (Zea mays) inbred lines display an exceptional degree of genomic diversity. F1 progeny of such inbred lines are often more vigorous than their parents, a phenomenon known as heterosis. In this study, we investigated how the genetic divergence of the maize inbred lines B73 and Mo17 and their F1 hybrid progeny is reflected in differential, nonadditive, and allelic expression patterns in primary root tissues. In pairwise comparisons of the four genotypes, the number of differentially expressed genes between the two parental inbred lines significantly exceeded those of parent versus hybrid comparisons in all four tissues under analysis. No differentially expressed genes were detected between reciprocal hybrids, which share the same nuclear genome. Moreover, hundreds of nonadditive and allelic expression ratios that were different from the expression ratios of the parents were observed in the reciprocal hybrids. The overlap of both nonadditive and allelic expression patterns in the reciprocal hybrids significantly exceeded the expected values. For all studied types of expression - differential, nonadditive, and allelic - substantial tissue-specific plasticity was observed. Significantly, nonsyntenic genes that evolved after the last whole genome duplication of a maize progenitor from genes with synteny to sorghum (Sorghum bicolor) were highly overrepresented among differential, nonadditive, and allelic expression patterns compared with the fraction of these genes among all expressed genes. This observation underscores the role of nonsyntenic genes in shaping the transcriptomic landscape of maize hybrids during the early developmental manifestation of heterosis in root tissues of maize hybrids. PMID:27208302

  18. Nonsyntenic Genes Drive Tissue-Specific Dynamics of Differential, Nonadditive, and Allelic Expression Patterns in Maize Hybrids.

    PubMed

    Baldauf, Jutta A; Marcon, Caroline; Paschold, Anja; Hochholdinger, Frank

    2016-06-01

    Distantly related maize (Zea mays) inbred lines display an exceptional degree of genomic diversity. F1 progeny of such inbred lines are often more vigorous than their parents, a phenomenon known as heterosis. In this study, we investigated how the genetic divergence of the maize inbred lines B73 and Mo17 and their F1 hybrid progeny is reflected in differential, nonadditive, and allelic expression patterns in primary root tissues. In pairwise comparisons of the four genotypes, the number of differentially expressed genes between the two parental inbred lines significantly exceeded those of parent versus hybrid comparisons in all four tissues under analysis. No differentially expressed genes were detected between reciprocal hybrids, which share the same nuclear genome. Moreover, hundreds of nonadditive and allelic expression ratios that were different from the expression ratios of the parents were observed in the reciprocal hybrids. The overlap of both nonadditive and allelic expression patterns in the reciprocal hybrids significantly exceeded the expected values. For all studied types of expression - differential, nonadditive, and allelic - substantial tissue-specific plasticity was observed. Significantly, nonsyntenic genes that evolved after the last whole genome duplication of a maize progenitor from genes with synteny to sorghum (Sorghum bicolor) were highly overrepresented among differential, nonadditive, and allelic expression patterns compared with the fraction of these genes among all expressed genes. This observation underscores the role of nonsyntenic genes in shaping the transcriptomic landscape of maize hybrids during the early developmental manifestation of heterosis in root tissues of maize hybrids. PMID:27208302

  19. Carotenoid biosynthetic and catabolic pathways: gene expression and carotenoid content in grains of maize landraces.

    PubMed

    da Silva Messias, Rafael; Galli, Vanessa; Dos Anjos E Silva, Sérgio Delmar; Rombaldi, Cesar Valmor

    2014-01-01

    Plant carotenoids have been implicated in preventing several age-related diseases, and they also provide vitamin A precursors; therefore, increasing the content of carotenoids in maize grains is of great interest. It is not well understood, however, how the carotenoid biosynthetic pathway is regulated. Fortunately, the maize germplasm exhibits a high degree of genetic diversity that can be exploited for this purpose. Here, the accumulation of carotenoids and the expression of genes from carotenoid metabolic and catabolic pathways were investigated in several maize landraces. The carotenoid content in grains varied from 10.03, in the white variety MC5, to 61.50 μg·g⁻¹, in the yellow-to-orange variety MC3, and the major carotenoids detected were lutein and zeaxanthin. PSY1 (phythoene synthase) expression showed a positive correlation with the total carotenoid content. Additionally, the PSY1 and HYD3 (ferredoxin-dependent di-iron monooxygenase) expression levels were positively correlated with β-cryptoxanthin and zeaxanthin, while CYP97C (cytochrome P450-type monooxygenase) expression did not correlate with any of the carotenoids. In contrast, ZmCCD1 (carotenoid dioxygenase) was more highly expressed at the beginning of grain development, as well as in the white variety, and its expression was inversely correlated with the accumulation of several carotenoids, suggesting that CCD1 is also an important enzyme to be considered when attempting to improve the carotenoid content in maize. The MC27 and MC1 varieties showed the highest HYD3/CYP97C ratios, suggesting that they are promising candidates for increasing the zeaxanthin content; in contrast, MC14 and MC7 showed low HYD3/CYP97C, suggesting that they may be useful in biofortification efforts aimed at promoting the accumulation of provitamin A. The results of this study demonstrate the use of maize germplasm to provide insight into the regulation of genes involved in the carotenoid pathway, which would thus

  20. Carotenoid Biosynthetic and Catabolic Pathways: Gene Expression and Carotenoid Content in Grains of Maize Landraces

    PubMed Central

    Messias, Rafael da Silva; Galli, Vanessa; Silva, Sérgio Delmar dos Anjos e; Rombaldi, Cesar Valmor

    2014-01-01

    Plant carotenoids have been implicated in preventing several age-related diseases, and they also provide vitamin A precursors; therefore, increasing the content of carotenoids in maize grains is of great interest. It is not well understood, however, how the carotenoid biosynthetic pathway is regulated. Fortunately, the maize germplasm exhibits a high degree of genetic diversity that can be exploited for this purpose. Here, the accumulation of carotenoids and the expression of genes from carotenoid metabolic and catabolic pathways were investigated in several maize landraces. The carotenoid content in grains varied from 10.03, in the white variety MC5, to 61.50 μg·g−1, in the yellow-to-orange variety MC3, and the major carotenoids detected were lutein and zeaxanthin. PSY1 (phythoene synthase) expression showed a positive correlation with the total carotenoid content. Additionally, the PSY1 and HYD3 (ferredoxin-dependent di-iron monooxygenase) expression levels were positively correlated with β-cryptoxanthin and zeaxanthin, while CYP97C (cytochrome P450-type monooxygenase) expression did not correlate with any of the carotenoids. In contrast, ZmCCD1 (carotenoid dioxygenase) was more highly expressed at the beginning of grain development, as well as in the white variety, and its expression was inversely correlated with the accumulation of several carotenoids, suggesting that CCD1 is also an important enzyme to be considered when attempting to improve the carotenoid content in maize. The MC27 and MC1 varieties showed the highest HYD3/CYP97C ratios, suggesting that they are promising candidates for increasing the zeaxanthin content; in contrast, MC14 and MC7 showed low HYD3/CYP97C, suggesting that they may be useful in biofortification efforts aimed at promoting the accumulation of provitamin A. The results of this study demonstrate the use of maize germplasm to provide insight into the regulation of genes involved in the carotenoid pathway, which would thus better

  1. Biodegradation of atrazine by three transgenic grasses and alfalfa expressing a modified bacterial atrazine chlorohydrolase gene.

    PubMed

    Vail, Andrew W; Wang, Ping; Uefuji, Hirotaka; Samac, Deborah A; Vance, Carroll P; Wackett, Lawrence P; Sadowsky, Michael J

    2015-06-01

    The widespread use of atrazine and other s-triazine herbicides to control weeds in agricultural production fields has impacted surface and groundwater in the United States and elsewhere. We previously reported the cloning, sequencing, and expression of six genes involved in the atrazine biodegradation pathway of Pseudomonas sp. strain ADP, which is initiated by atzA, encoding atrazine chlorohydrolase. Here we explored the use of enhanced expression of a modified bacterial atrazine chlorohydrolase, p-AtzA, in transgenic grasses (tall fescue, perennial ryegrass, and switchgrass) and the legume alfalfa for the biodegradation of atrazine. Enhanced expression of p-AtzA was obtained by using combinations of the badnavirus promoter, the maize alcohol dehydrogenase first intron, and the maize ubiquitin promoter. For alfalfa, we used the first intron of the 5'-untranslated region tobacco alcohol dehydrogenase gene and the cassava vein mosaic virus promoter. Resistance of plants to atrazine in agar-based and hydroponic growth assays was correlated with in vivo levels of gene expression and atrazine degradation. The in planta expression of p-atzA enabled transgenic tall fescue to transform atrazine into hydroxyatrazine and other metabolites. Results of our studies highlight the potential use of transgenic plants for bioremediating atrazine in the environment. PMID:25432082

  2. Male reproductive development: gene expression profiling of maize anther and pollen ontogeny

    PubMed Central

    Ma, Jiong; Skibbe, David S; Fernandes, John; Walbot, Virginia

    2008-01-01

    Background During flowering, central anther cells switch from mitosis to meiosis, ultimately forming pollen containing haploid sperm. Four rings of surrounding somatic cells differentiate to support first meiosis and later pollen dispersal. Synchronous development of many anthers per tassel and within each anther facilitates dissection of carefully staged maize anthers for transcriptome profiling. Results Global gene expression profiles of 7 stages representing 29 days of anther development are analyzed using a 44 K oligonucleotide array querying approximately 80% of maize protein-coding genes. Mature haploid pollen containing just two cell types expresses 10,000 transcripts. Anthers contain 5 major cell types and express >24,000 transcript types: each anther stage expresses approximately 10,000 constitutive and approximately 10,000 or more transcripts restricted to one or a few stages. The lowest complexity is present during meiosis. Large suites of stage-specific and co-expressed genes are identified through Gene Ontology and clustering analyses as functional classes for pre-meiotic, meiotic, and post-meiotic anther development. MADS box and zinc finger transcription factors with constitutive and stage-limited expression are identified. Conclusions We propose that the extensive gene expression of anther cells and pollen represents the key test of maize genome fitness, permitting strong selection against deleterious alleles in diploid anthers and haploid pollen. Because flowering plants show a substantial bias for male-sterile compared to female-sterile mutations, we propose that this fitness test is general. Because both somatic and germinal cells are transcriptionally quiescent during meiosis, we hypothesize that successful completion of meiosis is required to trigger maturation of anther somatic cells. PMID:19099579

  3. Representative taxa in field trials for environmental risk assessment of genetically modified maize.

    PubMed

    Albajes, R; Lumbierres, B; Pons, X; Comas, J

    2013-12-01

    When assessing the benefits and risks of transgenic crops, one consideration is their relative effects on non-target arthropod (NTA) abundance and functions within agroecosystems. Several laboratory and field trials have been conducted in Spain since the late 1990s to assess this issue. A consideration in the design of field trials is whether it is necessary to sample most NTAs living in the crop or only representative taxa that perform main ecological functions and have a good capacity to detect small changes in their abundance. Small changes in the field abundance of an effective representative taxon should be detectable using standard experimental protocols. The ability of a species to reveal differences across treatments may be analysed by examining the detectable treatment effects for surveyed non-target organisms. Analysis of data from several NTAs recorded in 14 field trials conducted over 10 years using complete block designs allowed us to select a number of representative taxa capable of detecting changes in the density or activity of arthropod herbivores, predators, parasitoids and decomposers in transgenic and non-transgenic maize varieties. The most suitable NTA as representative taxa (with detectable treatment effects below 50%) included leafhoppers among arthropod herbivores, Orius spp., Araneae, and Carabidae among predators, chalcidids, particularly the family Mymaridae, among parasitoids and Chloropidae as decomposer. Details of sampling techniques for each sampled taxa and their advantages and disadvantages are discussed. It is concluded that abundance of taxa is the most influential factor determining their capacity to detect changes caused by genetically modified varieties. PMID:23987801

  4. Expression of Fungal diacylglycerol acyltransferase2 Genes to Increase Kernel Oil in Maize[OA

    PubMed Central

    Oakes, Janette; Brackenridge, Doug; Colletti, Ron; Daley, Maureen; Hawkins, Deborah J.; Xiong, Hui; Mai, Jennifer; Screen, Steve E.; Val, Dale; Lardizabal, Kathryn; Gruys, Ken; Deikman, Jill

    2011-01-01

    Maize (Zea mays) oil has high value but is only about 4% of the grain by weight. To increase kernel oil content, fungal diacylglycerol acyltransferase2 (DGAT2) genes from Umbelopsis (formerly Mortierella) ramanniana and Neurospora crassa were introduced into maize using an embryo-enhanced promoter. The protein encoded by the N. crassa gene was longer than that of U. ramanniana. It included 353 amino acids that aligned to the U. ramanniana DGAT2A protein and a 243-amino acid sequence at the amino terminus that was unique to the N. crassa DGAT2 protein. Two forms of N. crassa DGAT2 were tested: the predicted full-length protein (L-NcDGAT2) and a shorter form (S-NcDGAT2) that encoded just the sequences that share homology with the U. ramanniana protein. Expression of all three transgenes in maize resulted in small but statistically significant increases in kernel oil. S-NcDGAT2 had the biggest impact on kernel oil, with a 26% (relative) increase in oil in kernels of the best events (inbred). Increases in kernel oil were also obtained in both conventional and high-oil hybrids, and grain yield was not affected by expression of these fungal DGAT2 transgenes. PMID:21245192

  5. Silicon modifies root anatomy, and uptake and subcellular distribution of cadmium in young maize plants

    PubMed Central

    Vaculík, Marek; Landberg, Tommy; Greger, Maria; Luxová, Miroslava; Stoláriková, Miroslava; Lux, Alexander

    2012-01-01

    Background and Aims Silicon (Si) has been shown to ameliorate the negative influence of cadmium (Cd) on plant growth and development. However, the mechanism of this phenomenon is not fully understood. Here we describe the effect of Si on growth, and uptake and subcellular distribution of Cd in maize plants in relation to the development of root tissues. Methods Young maize plants (Zea mays) were cultivated for 10 d hydroponically with 5 or 50 µm Cd and/or 5 mm Si. Growth parameters and the concentrations of Cd and Si were determined in root and shoot by atomic absorption spectrometry or inductively coupled plasma mass spectroscopy. The development of apoplasmic barriers (Casparian bands and suberin lamellae) and vascular tissues in roots were analysed, and the influence of Si on apoplasmic and symplasmic distribution of 109Cd applied at 34 nm was investigated between root and shoot. Key Results Si stimulated the growth of young maize plants exposed to Cd and influenced the development of Casparian bands and suberin lamellae as well as vascular tissues in root. Si did not affect the distribution of apoplasmic and symplasmic Cd in maize roots, but considerably decreased symplasmic and increased apoplasmic concentration of Cd in maize shoots. Conclusions Differences in Cd uptake of roots and shoots are probably related to the development of apoplasmic barriers and maturation of vascular tissues in roots. Alleviation of Cd toxicity by Si might be attributed to enhanced binding of Cd to the apoplasmic fraction in maize shoots. PMID:22455991

  6. Analysis of gene expression patterns and levels in maize hybrids and their parents.

    PubMed

    Nie, H S; Li, S P; Shan, X H; Wu, Y; Su, S Z; Liu, H K; Han, J Y; Yuan, Y P

    2015-01-01

    Heterosis has greatly contributed to conventional plant breeding and is widely used to increase crop plant productivity. However, although some studies have explored the mechanisms of heterosis at the genomic and transcriptome level, these mechanisms still remain unclear. The growth and development of maize seedlings and immature embryos have an important impact on subsequent production. This study investigated differentially expressed genes (DEGs) between parents and reciprocal hybrids in the seedling leaves, roots, and immature embryo 15 days after pollination using amplified fragment length polymorphism (AFLP)-based transcript profiling (cDNA-AFLP). We isolated 180, 170, and 108 genes from the leaves, roots, and immature embryos, respectively, that were differentially expressed between hybrids and parents. Sequencing and functional analysis revealed that 107 transcript-derived fragments in the roots and leaves and 90 in the immature embryos were involved in known functions, whereas many DEGs had roles in plant growth and development, photosynthesis, signal transduction, and seed germination. Quantitative reverse-transcription polymerase chain reaction analysis of relative expression levels between reciprocal hybrids and both parental genotypes of selected genes produced results that were consistent with cDNA-AFLP. We validated the expression patterns of 15 selected genes related to heterosis formation and revealed that most showed non-additive expression in one or both hybrids, including dominant, underdominant, and overdominant expression. This indicates that gene-regulatory interactions among parental alleles play an important role in heterosis during the early developmental stages of maize. PMID:26634505

  7. Endophytic Bacillus spp. produce antifungal lipopeptides and induce host defence gene expression in maize.

    PubMed

    Gond, Surendra K; Bergen, Marshall S; Torres, Mónica S; White, James F

    2015-03-01

    Endophytes are mutualistic symbionts within healthy plant tissues. In this study we isolated Bacillus spp. from seeds of several varieties of maize. Bacillus amyloliquifaciens or Bacillus subtilis were found to be present in all maize varieties examined in this study. To determine whether bacteria may produce antifungal compounds, generally lipopeptides in Bacillus spp., bacterial cultures were screened for production of lipopeptides. Lipopeptides were extracted by acid precipitation from liquid cultures of Bacillus spp. Lipopeptide extracts from Bacillus spp. isolated from Indian popcorn and yellow dent corn showed inhibitory activity against Fusarium moniliforme at 500μg per disk. Using MALDI-TOF mass spectrometry we detected the presence of antifungal iturin A, fengycin and bacillomycin in these isolates. PCR amplification also showed the presence of genes for iturin A and fengycin. B. subtilis (SG_JW.03) isolated from Indian popcorn showed strong inhibition of Arabidopsis seed mycoflora and enhanced seedling growth. We tested for the induction of defence gene expression in the host plant after treatment of plants with B. subtilis (SG_JW.03) and its lipopeptide extract using RT-qPCR. Roots of Indian popcorn seedlings treated with a suspension of B. subtilis (SG_JW.03) showed the induction of pathogenesis-related genes, including PR-1 and PR-4, which relate to plant defence against fungal pathogens. The lipopeptide extract alone did not increase the expression of these pathogenesis-related genes. Based on our study of maize endophytes, we hypothesize that, bacterial endophytes that naturally occur in many maize varieties may function to protect hosts by secreting antifungal lipopeptides that inhibit pathogens as well as inducing the up-regulation of pathogenesis-related genes of host plants (systemic acquired resistance). PMID:25497916

  8. Transient Gene Expression in Maize, Rice, and Wheat Cells Using an Airgun Apparatus 1

    PubMed Central

    Oard, James H.; Paige, David F.; Simmonds, John A.; Gradziel, Thomas M.

    1990-01-01

    An airgun apparatus has been constructed for transient gene expression studies of monocots. This device utilizes compressed air from a commercial airgun to propel macroprojectile and DNA-coated tungsten particles. The β-glucuronidase (GUS) reporter gene was used to monitor transient expression in three distinct cell types of maize (Zea mays), rice (Oryza sativa), and wheat (Triticum aestivum). The highest level of GUS activity in cultured maize cells was observed when distance between stopping plate and target cells was adjusted to 4.3 centimeters. Efficiency of transformation was estimated to be 4.4 × 10−3. In a partial vacuum of 700 millimeters Hg, velocity of macroprojectile was measured at 520 meters per second with a 6% reduction in velocity at atmospheric pressure. A polyethylene film placed in the breech before firing contributed to a 12% increase in muzzle velocity. A 700 millimeters Hg level of vacuum was necessary for maximum number of transfornants. GUS expression was also detected in wheat leaf base tissue of microdissected shoot apices. High levels of transient gene expression were also observed in hard, compact embryogenic callus of rice. These results show that the airgun apparatus is a convenient, safe, and low-cost device for rapid transient gene expression studies in cereals. Images Figure 7 Figure 8 Figure 9 PMID:16667278

  9. Expression of genes related to tolerance to low temperature for maize seed germination.

    PubMed

    Silva-Neta, I C; Pinho, E V; Veiga, A D; Pìnho, R G; Guimarães, R M; Caixeta, F; Santos, H O; Marques, T L

    2015-01-01

    The aim of this study was to characterize maize lines tolerant to cold temperatures during the germination process. Seeds from lines with different levels of tolerance to low temperatures were used; 3 lines were classified as tolerant and 3 as susceptible to low germination temperatures. A field was set up to multiply seeds from selected lines. After the seeds were harvested and classified, we conducted physiological tests and analyzed fatty acid content of palmitic, stearic, oleic, linoleic, linolenic, and eicosenoic acids. In proteomic analysis, the expression of heat-resistant proteins, including catalase, peroxidase, esterase, superoxide dismutase, and α-amylase, were evaluated. Transcript analysis was used to measure the expression of the genes AOX1, AOX2, ZmMPK-17, and ZmAN-13. The material showing the highest susceptibility to low germination temperatures contained high saturated fatty acid content. Expression of α-amylase in seeds soaked for 72 h at a temperature of 10°C was lower than expression of α-amylase when soaked at 25°C for the same amount of time. We observed variation in the expression of heat-resistant proteins in seeds of the lines evaluated. The genes AOX and Zm-AN13 were promising for use in identifying maize materials that are tolerant to low germination temperatures. PMID:25867416

  10. Estimation of the minimum uncertainty of DNA concentration in a genetically modified maize sample candidate certified reference material.

    PubMed

    Prokisch, J; Zeleny, R; Trapmann, S; Le Guern, L; Schimmel, H; Kramer, G N; Pauwels, J

    2001-08-01

    Homogeneity testing and the determination of minimum sample mass are an important part of the certification of reference materials. The smallest theoretically achievable uncertainty of certified concentration values is limited by the concentration distribution of analyte in the different particle size fractions of powdered biological samples. This might be of special importance if the reference material is prepared by dry mixing, a dilution technique which is used for the production of the new and third generation of genetically modified (GMO) plant certified reference materials. For the production of dry mixed PMON 810 maize reference material a computer program was developed to calculate the theoretically smallest uncertainty for a selected sample intake. This model was used to compare three differently milled maize samples, and the effect of dilution on the uncertainty of the DNA content of GMO maize was estimated as well. In the case of a 50-mg sample mass the lowest achievable standard deviation was 2% for the sample containing 0.1% GMO and the minimum deviation was less than 0.5% for the sample containing 5% GMO. PMID:11569879

  11. Isolation, structural analysis, and expression characteristics of the maize TIFY gene family.

    PubMed

    Zhang, Zhongbao; Li, Xianglong; Yu, Rong; Han, Meng; Wu, Zhongyi

    2015-10-01

    TIFY, previously known as ZIM, comprises a plant-specific family annotated as transcription factors that might play important roles in stress response. Despite TIFY proteins have been reported in Arabidopsis and rice, a comprehensive and systematic survey of ZmTIFY genes has not yet been conducted. To investigate the functions of ZmTIFY genes in this family, we isolated and characterized 30 ZmTIFY (1 TIFY, 3 ZML, and 26 JAZ) genes in an analysis of the maize (Zea mays L.) genome in this study. The 30 ZmTIFY genes were distributed over eight chromosomes. Multiple alignment and motif display results indicated that all ZmTIFY proteins share two conserved TIFY and Jas domains. Phylogenetic analysis revealed that the ZmTIFY family could be divided into two groups. Putative cis-elements, involved in abiotic stress response, phytohormones, pollen grain, and seed development, were detected in the promoters of maize TIFY genes. Microarray data showed that the ZmTIFY genes had tissue-specific expression patterns in various maize developmental stages and in response to biotic and abiotic stresses. The results indicated that ZmTIFY4, 5, 8, 26, and 28 were induced, while ZmTIFY16, 13, 24, 27, 18, and 30 were suppressed, by drought stress in the maize inbred lines Han21 and Ye478. ZmTIFY1, 19, and 28 were upregulated after infection by three pathogens, whereas ZmTIFY4, 13, 21, 23, 24, and 26 were suppressed. These results indicate that the ZmTIFY family may have vital roles in response to abiotic and biotic stresses. The data presented in this work provide vital clues for further investigating the functions of the genes in the ZmTIFY family. PMID:25862669

  12. Involvement of intracellular calcium in anaerobic gene expression and survival of maize seedlings.

    PubMed Central

    Subbaiah, C C; Zhang, J; Sachs, M M

    1994-01-01

    Ca-mediated processes are known to be involved in transducing many developmental, hormonal, and environmental cues in plant cells. In this study, the role of Ca in the perception of anoxic stress signals by maize (Zea mays L. cv B73) roots was assessed by studying the effect of various Ca antagonists on the induction of alcohol dehydrogenase (ADH) and sucrose synthase mRNA as well as ADH activity under anoxia. The effect of these compounds on the poststress recovery of the seedlings was also monitored. Ruthenium red (RR), an inhibitor of organellar Ca fluxes, repressed the anoxic activation of the alcohol dehydrogenase1 and shrunken1 genes as measured by their transcript levels as well as ADH activity. Furthermore, RR-treated seedlings could not recover even after only 2 h of flooding, in contrast to untreated B73 seedlings that survived 72 h of submergence. Ca, when supplied along with RR, allowed normal anoxic gene expression and also prevented the RR-imposed death of the seedlings from short-term anoxia. Ca (45Ca) fluxes were measured in maize roots to elucidate the mode of action of RR. RR abolished anoxia-stimulated 45Ca influx into maize roots but did not affect aerobic Ca2+ uptake, unlike a few other antagonists that blocked both the aerobic and anoxic fluxes. However, Ca uptake across the plasma membrane was not necessary for the adaptive response to anoxia, since chelation of extracellular Ca by ethyleneglycol-bis(beta-aminoethyl ether)-N,N'-tetraacetic acid or 1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid did not affect the induction of ADH activity or poststress survival of flooded seedlings. The data suggest that RR may act on one of the intracellular stores of Ca and the Ca mobilized from this source is a physiological transducer of anoxic stress signals in maize roots. PMID:7518090

  13. A Maize (E)-β-Caryophyllene Synthase Implicated in Indirect Defense Responses against Herbivores Is Not Expressed in Most American Maize Varieties[W][OA

    PubMed Central

    Köllner, Tobias G.; Held, Matthias; Lenk, Claudia; Hiltpold, Ivan; Turlings, Ted C.J.; Gershenzon, Jonathan; Degenhardt, Jörg

    2008-01-01

    The sesquiterpene (E)-β-caryophyllene is emitted by maize (Zea mays) leaves in response to attack by lepidopteran larvae like Spodoptera littoralis and released from roots after damage by larvae of the coleopteran Diabrotica virgifera virgifera. We identified a maize terpene synthase, Terpene Synthase 23 (TPS23), that produces (E)-β-caryophyllene from farnesyl diphosphate. The expression of TPS23 is controlled at the transcript level and induced independently by D. v. virgifera damage in roots and S. littoralis damage in leaves. We demonstrate that (E)-β-caryophyllene can attract natural enemies of both herbivores: entomopathogenic nematodes below ground and parasitic wasps, after an initial learning experience, above ground. The biochemical properties of TPS23 are similar to those of (E)-β-caryophyllene synthases from dicotyledons but are the result of repeated evolution. The sequence of TPS23 is maintained by positive selection in maize and its closest wild relatives, teosinte (Zea sp) species. The gene encoding TPS23 is active in teosinte species and European maize lines, but decreased transcription in most North American lines resulted in the loss of (E)-β-caryophyllene production. We argue that the (E)-β-caryophyllene defense signal was lost during breeding of the North American lines and that its restoration might help to increase the resistance of these lines against agronomically important pests. PMID:18296628

  14. Isolation, structural analysis, and expression characteristics of the maize nuclear factor Y gene families.

    PubMed

    Zhang, Zhongbao; Li, Xianglong; Zhang, Chun; Zou, Huawen; Wu, Zhongyi

    2016-09-16

    NUCLEAR FACTOR-Y (NF-Y) has been shown to play an important role in growth, development, and response to environmental stress. A NF-Y complex, which consists of three subunits, NF-YA, NF-YB, and, NF-YC, binds to CCAAT sequences in a promoter to control the expression of target genes. Although NF-Y proteins have been reported in Arabidopsis and rice, a comprehensive and systematic analysis of ZmNF-Y genes has not yet been performed. To examine the functions of ZmNF-Y genes in this family, we isolated and characterized 50 ZmNF-Y (14 ZmNF-YA, 18 ZmNF-YB, and 18 ZmNF-YC) genes in an analysis of the maize genome. The 50 ZmNF-Y genes were distributed on all 10 maize chromosomes, and 12 paralogs were identified. Multiple alignments showed that maize ZmNF-Y family proteins had conserved regions and relatively variable N-terminal or C-terminal domains. The comparative syntenic map illustrated 40 paralogous NF-Y gene pairs among the 10 maize chromosomes. Microarray data showed that the ZmNF-Y genes had tissue-specific expression patterns in various maize developmental stages and in response to biotic and abiotic stresses. The results suggested that ZmNF-YB2, 4, 8, 10, 13, and 16 and ZmNF-YC6, 8, and 15 were induced, while ZmNF-YA1, 3, 4, 6, 7, 10, 12, and 13, ZmNF-YB15, and ZmNF-YC3 and 9 were suppressed by drought stress. ZmNF-YA3, ZmNF-YA8 and ZmNF-YA12 were upregulated after infection by the three pathogens, while ZmNF-YA1 and ZmNF-YB2 were suppressed. These results indicate that the ZmNF-Ys may have significant roles in the response to abiotic and biotic stresses. PMID:27498027

  15. Activity and ecological implications of maize-expressed transgenic endo-1,4-β-D-glucanase in agricultural soils.

    PubMed

    Kenny, Adam J; Wolt, Jeffrey D

    2014-09-01

    Plant expression of thermostable endoglucanase (E1) has been proposed for improved conversion of lignocellulose to ethanol for fuel production. Residues of E1-expressing maize may affect ecological services (e.g., C mineralization and biogeochemical cycling) on soils where they occur. Therefore, the activity of residual E1 was investigated using soils amended with bacterial and plant-solubilized E1 compared with soil endogenous activity and residual activity from a mesostable cellulase (Aspergillus and Trichoderma spp.). An optimized analytical method involving a carboxymethyl cellulose substrate and dinitrosalicylic acid detection effectively assayed endoglucanase activity in amended and unamended soils and was used for determining E1 activity in 3 representative soils. The effect of E1 on soil carbon mineralization was determined by comparing CO(2) evolution from soils amended with transgenic E1-expressing and wild-type maize tissue. Extraction and recovery of the mesostable comparator, bacterial E1, and plant-soluble E1 showed nearly complete loss of exogenous endoglucanase activity within a 24-h period. Carbon mineralization indicated no significant difference between soils amended with either the transgenic E1 or wild-type maize tissue. These results indicate that maize residues expressing up to 30 µg E1/g tissue negligibly affect soil endoglucanase activity and CO(2) respiration for representative soils where transgenic E1 maize may be grown. PMID:24863456

  16. Bt-maize (MON810) and Non-GM Soybean Meal in Diets for Atlantic Salmon (Salmo salar L.) Juveniles – Impact on Survival, Growth Performance, Development, Digestive Function, and Transcriptional Expression of Intestinal Immune and Stress Responses

    PubMed Central

    Gu, Jinni; Bakke, Anne Marie; Valen, Elin C.; Lein, Ingrid; Krogdahl, Åshild

    2014-01-01

    Responses in Atlantic salmon (Salmo salar L.) juveniles (fry) fed diets containing genetically modified maize (Bt-maize, MON810) expressing Cry1Ab protein from first-feeding were investigated during a 99-day feeding trial. Four experimental diets were made; each diet contained ∼20% maize, either Bt-maize or its near-isogenic maternal line (non-GM maize). One pair was fishmeal-based while the other pair included standard (extracted) soybean meal (SBM; 16.7% inclusion level), with the intention of investigating responses to the maize varieties in healthy fish as well as in immunologically challenged fish with SBM-induced distal intestinal inflammation, respectively. Three replicate tanks of fry (0.17±0.01 g; initial mean weight ± SEM) were fed one of the four diets and samples were taken on days 15, 36, 48 and 99. Survival, growth performance, whole body composition, digestive function, morphology of intestine, liver and skeleton, and mRNA expression of some immune and stress response parameters in the distal intestine were evaluated. After 99 days of feeding, survival was enhanced and the intended SBM-induced inflammatory response in the distal intestine of the two groups of SBM-fed fish was absent, indicating that the juvenile salmon were tolerant to SBM. Mortality, growth performance and body composition were similar in fish fed the two maize varieties. The Bt-maize fed fish, however, displayed minor but significantly decreased digestive enzyme activities of leucine aminopeptidase and maltase, as well as decreased concentration of gut bile salts, but significantly increased amylase activity at some sampling points. Histomorphological, radiographic and mRNA expression evaluations did not reveal any biologically relevant effects of Bt-maize in the gastrointestinal tract, liver or skeleton. The results suggest that the Cry1Ab protein or other compositional differences in GM Bt-maize may cause minor alterations in intestinal responses in juvenile salmon, but

  17. Bt-maize (MON810) and non-GM soybean meal in diets for Atlantic salmon (Salmo salar L.) juveniles--impact on survival, growth performance, development, digestive function, and transcriptional expression of intestinal immune and stress responses.

    PubMed

    Gu, Jinni; Bakke, Anne Marie; Valen, Elin C; Lein, Ingrid; Krogdahl, Åshild

    2014-01-01

    Responses in Atlantic salmon (Salmo salar L.) juveniles (fry) fed diets containing genetically modified maize (Bt-maize, MON810) expressing Cry1Ab protein from first-feeding were investigated during a 99-day feeding trial. Four experimental diets were made; each diet contained ∼20% maize, either Bt-maize or its near-isogenic maternal line (non-GM maize). One pair was fishmeal-based while the other pair included standard (extracted) soybean meal (SBM; 16.7% inclusion level), with the intention of investigating responses to the maize varieties in healthy fish as well as in immunologically challenged fish with SBM-induced distal intestinal inflammation, respectively. Three replicate tanks of fry (0.17±0.01 g; initial mean weight ± SEM) were fed one of the four diets and samples were taken on days 15, 36, 48 and 99. Survival, growth performance, whole body composition, digestive function, morphology of intestine, liver and skeleton, and mRNA expression of some immune and stress response parameters in the distal intestine were evaluated. After 99 days of feeding, survival was enhanced and the intended SBM-induced inflammatory response in the distal intestine of the two groups of SBM-fed fish was absent, indicating that the juvenile salmon were tolerant to SBM. Mortality, growth performance and body composition were similar in fish fed the two maize varieties. The Bt-maize fed fish, however, displayed minor but significantly decreased digestive enzyme activities of leucine aminopeptidase and maltase, as well as decreased concentration of gut bile salts, but significantly increased amylase activity at some sampling points. Histomorphological, radiographic and mRNA expression evaluations did not reveal any biologically relevant effects of Bt-maize in the gastrointestinal tract, liver or skeleton. The results suggest that the Cry1Ab protein or other compositional differences in GM Bt-maize may cause minor alterations in intestinal responses in juvenile salmon, but

  18. Expression and properties of the mitochondrial and cytosolic forms of fumarase in germinating maize seeds.

    PubMed

    Eprintsev, Alexander T; Fedorin, Dmitry N; Starinina, Elena V; Igamberdiev, Abir U

    2014-10-01

    Fumarase (EC 4.2.1.2) catalyzes reversible interconversion of malate and fumarate. It is usually associated with the tricarboxylic acid cycle in mitochondria, although the cytosolic form has also been detected. We investigated the expression of two fumarase genes and activities of the mitochondrial and cytosolic isoforms of fumarase in maize (Zea mays) scutellum during germination. Both isoforms were purified to electrophoretic homogeneity. The cytosolic form had low optimum pH (6.5) and high affinity to malate (Km 5 μM) when compared with the mitochondrial form (optimum pH 7.0, Km 50 μM). The cytosolic form was strongly activated by Mg(2+) and even more by Mn(2+) , whereas the mitochondrial form was moderately activated by Mg(2+) and Mn(2+) was less effective. The highest fumarase activity in scutellum and a high expression of the gene encoding the cytosolic form were observed during the maximal activity of the glyoxylate cycle. In leaves, the localization of fumarase is only mitochondrial and only one fumarase gene is expressed. It is concluded that the function of cytosolic fumarase in maize scutellum can be related to metabolism of succinate formed in the glyoxylate cycle. PMID:24611547

  19. Characterization and expression analysis of six MADS-box genes in maize (Zea mays L.).

    PubMed

    Zhang, Zhongbao; Li, Huiyong; Zhang, Dengfeng; Liu, Yinghui; Fu, Jing; Shi, Yunsu; Song, Yanchun; Wang, Tianyu; Li, Yu

    2012-05-15

    MADS-box genes encode a family of transcription factors, which control diverse developmental processes in flowering plants, with organs ranging from roots, flowers and fruits. In this study, six maize cDNAs encoding MADS-box proteins were isolated. BLASTX searches and phylogenetic analysis indicated that the six MADS-box genes belonging to the AGL2-like clade. qRT-PCR analysis revealed that these genes had differential expression patterns in different organs in maize. The results of yeast one-hybrid system indicated that the protein ZMM3-1, ZMM3-2, ZMM6, ZMM7-L, ZMM8-L and ZMM14-L had transcriptional activation activity. Subcellular localization of ZMM7-L demonstrated that the fluorescence of ZMM7-L-GFP was mainly detected in the nuclei of onion epidermal cells. qRT-PCR analysis for expression pattern of ZMM7-L showed that the gene was up-regulated by abiotic stresses and down-regulated by exogenous ABA. The germination rates of over-expression transgenic lines were lower than that of the wild type on medium with 150 mM NaCl, 350 mM mannitol. These results indicated that ZMM7-L might be a negative transcription factor responsive to abiotic stresses. PMID:22440334

  20. Development of quantitative duplex real-time PCR method for screening analysis of genetically modified maize.

    PubMed

    Oguchi, Taichi; Onishi, Mari; Minegishi, Yasutaka; Kurosawa, Yasunori; Kasahara, Masaki; Akiyama, Hiroshi; Teshima, Reiko; Futo, Satoshi; Furui, Satoshi; Hino, Akihiro; Kitta, Kazumi

    2009-06-01

    A duplex real-time PCR method was developed for quantitative screening analysis of GM maize. The duplex real-time PCR simultaneously detected two GM-specific segments, namely the cauliflower mosaic virus (CaMV) 35S promoter (P35S) segment and an event-specific segment for GA21 maize which does not contain P35S. Calibration was performed with a plasmid calibrant specially designed for the duplex PCR. The result of an in-house evaluation suggested that the analytical precision of the developed method was almost equivalent to those of simplex real-time PCR methods, which have been adopted as ISO standard methods for the analysis of GMOs in foodstuffs and have also been employed for the analysis of GMOs in Japan. In addition, this method will reduce both the cost and time requirement of routine GMO analysis by half. The high analytical performance demonstrated in the current study would be useful for the quantitative screening analysis of GM maize. We believe the developed method will be useful for practical screening analysis of GM maize, although interlaboratory collaborative studies should be conducted to confirm this. PMID:19602858

  1. Heat-resistant protein expression during germination of maize seeds under water stress.

    PubMed

    Abreu, V M; Silva Neta, I C; Von Pinho, E V R; Naves, G M F; Guimarães, R M; Santos, H O; Von Pinho, R G

    2016-01-01

    Low water availability is one of the factors that limit agricultural crop development, and hence the development of genotypes with increased water stress tolerance is a challenge in plant breeding programs. Heat-resistant proteins have been widely studied, and are reported to participate in various developmental processes and to accumulate in response to stress. This study aimed to evaluate heat-resistant protein expression under water stress conditions during the germination of maize seed inbreed lines differing in their water stress tolerance. Maize seed lines 91 and 64 were soaked in 0, -0.3, -0.6, and -0.9 MPa water potential for 0, 6, 12, 18, and 24 h. Line 91 is considered more water stress-tolerant than line 64. The analysis of heat-resistant protein expression was made by gel electrophoresis and spectrophotometry. In general, higher expression of heat-resistant proteins was observed in seeds from line 64 subjected to shorter soaking periods and lower water potentials. However, in the water stress-tolerant line 91, a higher expression was observed in seeds that were subjected to -0.3 and -0.6 MPa water potentials. In the absence of water stress, heat-resistant protein expression was reduced with increasing soaking period. Thus, there was a difference in heat-resistant protein expression among the seed lines differing in water stress tolerance. Increased heat-resistant protein expression was observed in seeds from line 91 when subjected to water stress conditions for longer soaking periods. PMID:27525950

  2. Development of resistance to eCry3.1Ab-expressing transgenic maize in a laboratory-selected population of western corn rootworm (Coleoptera: Chrysomelidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A laboratory colony of western corn rootworm, Diabrotica virgifera virgifera LeConte, was selected for resistance to transgenic maize expressing the eCry3.1ab protein. The selected colony was developed by rearing larvae on non-elite, non-commercial Bt maize expressing the eCry3.1Ab protein. After ...

  3. Inheritance and expression of lysine plus threonine resistance selected in maize tissue culture

    PubMed Central

    Hibberd, K. A.; Green, C. E.

    1982-01-01

    Selection for resistance to growth inhibition by lysine plus threonine in equimolar concentrations (LT) in tissue cultures of maize yielded a stable resistant line, LT19. Genetic analysis of progeny of plants regenerated from LT19 showed that LT resistance was inherited as a single dominant nuclear gene, temporarily designated Ltr*-19. Tissue cultures initiated from resistant embryos required 5-10 times higher levels of LT to inhibit growth than did cultures from LT-sensitive embryos. LT resistance in Ltr*-19 was expressed as much reduced inhibition of root and shoot growth in the presence of LT. The free pool of threonine was increased 6 times in cultures initiated from immature embryos of LT-resistant plants, and 75-100 times in kernels homozygous for Ltr*-19, as compared to cultures and kernels from LT-sensitive embryos and plants, respectively. Overproduction of free threonine increased the total threonine content in homozygous Ltr*-19 kernels by 33-59%. The results demonstrate that LT resistance selected with tissue culture methods is heritable and is expressed in cultures, seedlings, and kernels. Furthermore, they demonstrate a method to obtain amino acid-overproducer mutants in maize, which have the potential to increase substantially specific amino acids in kernels. The capability to increase specifically the nutritionally limiting amino acid(s) could have important nutritional implications for the grain of cereals and other crops. PMID:16593148

  4. Complexity and Genetic Variability of Heat-Shock Protein Expression in Isolated Maize Microspores.

    PubMed Central

    Magnard, J. L.; Vergne, P.; Dumas, C.

    1996-01-01

    The expression of heat-shock proteins (HSPs) in isolated maize (Zea mays L.) microspores has been investigated using high-resolution two-dimensional electrophoresis coupled to immunodetection and fluorography of in vivo synthesized proteins. To this end, homogeneous and viable populations of microspores have been purified in sufficient amounts for molecular analysis from plants grown in controlled conditions. Appropriate conditions for thermal stress application have been defined. The analysis revealed that isolated microspores from maize display a classical heat-shock response characterized by the repression of the normal protein synthesis and the expression of a set of HSPs. A high complexity of the response was demonstrated, with numerous different HSPs being resolved in each known major HSP molecular weight class. However, the extent of this heat-shock response is limited in that some of these HSPs do not accumulate at high levels following temperature elevation. Comparative analysis of the heat-shock responses of microspores isolated from five genotypes demonstrated high levels of genetic variability. Furthermore, many HSPs were detected in microspores at control temperature, indicating a possible involvement of these proteins in pollen development at stages close to first pollen mitosis. PMID:12226349

  5. Molecular cloning of starch synthase I from maize (W64) endosperm and expression in Escherichia coli.

    PubMed

    Knight, M E; Harn, C; Lilley, C E; Guan, H; Singletary, G W; MuForster, C; Wasserman, B P; Keeling, P L

    1998-06-01

    A full length cDNA clone encoding a starch synthase (zSS) from maize endosperm (inbred line W64) was isolated and characterized. The cDNA clone (Ss1) is 2907 bp in length and contains an open reading frame of 1866 bp corresponding to a polypeptide of 622 amino acid residues including a transit peptide of 39 amino acids. The Ss1 cDNA clone was identified as zSSI by its direct alignment with sequences to: (i) the N-terminus obtained from the granule-associated form of the zSSI polypeptide, (ii) four internal peptide fragments obtained from the granule-associated form of the zSSI protein, and (iii) one internal fragment from the soluble form of the zSSI protein. The deduced amino acid sequence of Ss1 shares 75.7% sequence identity with rice soluble Ss and contains the highly conserved KSGGLGDV putative ADP-Glc binding site. Moreover, Ss1 exhibited significant activity when expressed in E. coli and the expressed protein is recognized by the antibody raised against the granule associated zSSI protein. Ss1 transcripts were detected in endosperm beginning at 15 days after pollination, but were not found in embryo, leaf or root. Maize contains a single copy of the Ss1 gene, which maps close to the Waxy locus of chromosome 9. PMID:9675904

  6. Expressed proteins of Herbaspirillum seropedicae in maize (DKB240) roots-bacteria interaction revealed using proteomics.

    PubMed

    Ferrari, Cibele Santos; Amaral, Fernanda Plucani; Bueno, Jessica Cavalheiro Ferreira; Scariot, Mirella Christine; Valentim-Neto, Pedro Alexandre; Arisi, Ana Carolina Maisonnave

    2014-11-01

    Several molecular tools have been used to clarify the basis of plant-bacteria interaction; however, the mechanism behind the association is still unclear. In this study, we used a proteomic approach to investigate the root proteome of Zea mays (cv. DKB240) inoculated with Herbaspirillum seropedicae strain SmR1 grown in vitro and harvested 7 days after inoculation. Eighteen differentially accumulated proteins were observed in root samples, ten of which were identified by MALDI-TOF mass spectrometry peptide mass fingerprint. Among the identified proteins, we observed three proteins present exclusively in inoculated root samples and six upregulated proteins and one downregulated protein relative to control. Differentially expressed maize proteins were identified as hypothetical protein ZEAMMB73_483204, hypothetical protein ZEAMMB73_269466, and tubulin beta-7 chain. The following were identified as H. seropedicae proteins: peroxiredoxin protein, EF-Tu elongation factor protein, cation transport ATPase, NADPH:quinone oxidoreductase, dinitrogenase reductase, and type III secretion ATP synthase. Our results presented the first evidence of type III secretion ATP synthase expression during H. seropedicae-maize root interaction. PMID:25173675

  7. Transgene Expression and Bt Protein Content in Transgenic Bt Maize (MON810) under Optimal and Stressful Environmental Conditions

    PubMed Central

    Trtikova, Miluse; Wikmark, Odd Gunnar; Zemp, Niklaus; Widmer, Alex; Hilbeck, Angelika

    2015-01-01

    Bt protein content in transgenic insect resistant (Bt) maize may vary between tissues within plants and between plants growing under different environmental conditions. However, it is unknown whether and how Bt protein content correlates with transgene expression, and whether this relationship is influenced by stressful environmental conditions. Two Bt maize varieties containing the same transgene cassette (MON 810) were grown under optimal and stressful conditions. Before and during stress exposure, the upper leaves were analysed for transgene expression using quantitative RT-PCR and for Bt content using ELISA. Under optimal conditions there was no significant difference in the transgene expression between the two investigated Bt maize varieties whereas Bt protein content differed significantly. Transgene expression was correlated with Bt protein content in only one of the varieties. Under stressful environmental conditions we found similar transgene expressions as under optimal conditions but Bt content responded differently. These results suggest that Bt content is not only controlled by the transgene expression but is also dependent on the genetic background of the maize variety. Under stressful conditions the concentration of Bt protein is even more difficult to predict. PMID:25853814

  8. Transgene expression and Bt protein content in transgenic Bt maize (MON810) under optimal and stressful environmental conditions.

    PubMed

    Trtikova, Miluse; Wikmark, Odd Gunnar; Zemp, Niklaus; Widmer, Alex; Hilbeck, Angelika

    2015-01-01

    Bt protein content in transgenic insect resistant (Bt) maize may vary between tissues within plants and between plants growing under different environmental conditions. However, it is unknown whether and how Bt protein content correlates with transgene expression, and whether this relationship is influenced by stressful environmental conditions. Two Bt maize varieties containing the same transgene cassette (MON 810) were grown under optimal and stressful conditions. Before and during stress exposure, the upper leaves were analysed for transgene expression using quantitative RT-PCR and for Bt content using ELISA. Under optimal conditions there was no significant difference in the transgene expression between the two investigated Bt maize varieties whereas Bt protein content differed significantly. Transgene expression was correlated with Bt protein content in only one of the varieties. Under stressful environmental conditions we found similar transgene expressions as under optimal conditions but Bt content responded differently. These results suggest that Bt content is not only controlled by the transgene expression but is also dependent on the genetic background of the maize variety. Under stressful conditions the concentration of Bt protein is even more difficult to predict. PMID:25853814

  9. Abscisic acid and stress signals induce Viviparous1 expression in seed and vegetative tissues of maize.

    PubMed

    Cao, Xueyuan; Costa, Liliana M; Biderre-Petit, Corinne; Kbhaya, Bouchab; Dey, Nrisingha; Perez, Pascual; McCarty, Donald R; Gutierrez-Marcos, Jose F; Becraft, Philip W

    2007-02-01

    Viviparous1 (Vp1) encodes a B3 domain-containing transcription factor that is a key regulator of seed maturation in maize (Zea mays). However, the mechanisms of Vp1 regulation are not well understood. To examine physiological factors that may regulate Vp1 expression, transcript levels were monitored in maturing embryos placed in culture under different conditions. Expression of Vp1 decreased after culture in hormone-free medium, but was induced by salinity or osmotic stress. Application of exogenous abscisic acid (ABA) also induced transcript levels within 1 h in a dose-dependent manner. The Vp1 promoter fused to beta-glucuronidase or green fluorescent protein reproduced the endogenous Vp1 expression patterns in transgenic maize plants and also revealed previously unknown expression domains of Vp1. The Vp1 promoter is active in the embryo and aleurone cells of developing seeds and, upon drought stress, was also found in phloem cells of vegetative tissues, including cobs, leaves, and stems. Sequence analysis of the Vp1 promoter identified a potential ABA-responsive complex, consisting of an ACGT-containing ABA response element (ABRE) and a coupling element 1-like motif. Electrophoretic mobility shift assay confirmed that the ABRE and putative coupling element 1 components specifically bound proteins in embryo nuclear protein extracts. Treatment of embryos in hormone-free Murashige and Skoog medium blocked the ABRE-protein interaction, whereas exogenous ABA or mannitol treatment restored this interaction. Our data support a model for a VP1-dependent positive feedback mechanism regulating Vp1 expression during seed maturation. PMID:17208960

  10. [Development and validation of event-specific quantitative PCR method for genetically modified maize LY038].

    PubMed

    Mano, Junichi; Masubuchi, Tomoko; Hatano, Shuko; Futo, Satoshi; Koiwa, Tomohiro; Minegishi, Yasutaka; Noguchi, Akio; Kondo, Kazunari; Akiyama, Hiroshi; Teshima, Reiko; Kurashima, Takeyo; Takabatake, Reona; Kitta, Kazumi

    2013-01-01

    In this article, we report a novel real-time PCR-based analytical method for quantitation of the GM maize event LY038. We designed LY038-specific and maize endogenous reference DNA-specific PCR amplifications. After confirming the specificity and linearity of the LY038-specific PCR amplification, we determined the conversion factor required to calculate the weight-based content of GM organism (GMO) in a multilaboratory evaluation. Finally, in order to validate the developed method, an interlaboratory collaborative trial according to the internationally harmonized guidelines was performed with blind DNA samples containing LY038 at the mixing levels of 0, 0.5, 1.0, 5.0 and 10.0%. The precision of the method was evaluated as the RSD of reproducibility (RSDR), and the values obtained were all less than 25%. The limit of quantitation of the method was judged to be 0.5% based on the definition of ISO 24276 guideline. The results from the collaborative trial suggested that the developed quantitative method would be suitable for practical testing of LY038 maize. PMID:23470871

  11. Gravity-stimulated changes in auxin and invertase gene expression in maize pulvinal cells

    NASA Technical Reports Server (NTRS)

    Long, Joanne C.; Zhao, Wei; Rashotte, Aaron M.; Muday, Gloria K.; Huber, Steven C.; Brown, C. S. (Principal Investigator)

    2002-01-01

    Maize (Zea mays) stem gravitropism involves differential elongation of cells within a highly specialized region, the stem internodal pulvinus. In the present study, we investigated factors that control gravitropic responses in this system. In the graviresponding pulvinus, hexose sugars (D-Glc and D-Fru) accumulated asymmetrically across the pulvinus. This correlated well with an asymmetric increase in acid invertase activity across the pulvinus. Northern analyses revealed asymmetric induction of one maize acid invertase gene, Ivr2, consistent with transcriptional regulation by gravistimulation. Several lines of evidence indicated that auxin redistribution, as a result of polar auxin transport, is necessary for gravity-stimulated Ivr2 transcript accumulation and differential cell elongation across the maize pulvinus. First, the auxin transport inhibitor, N-1-naphthylphthalamic acid, inhibited gravistimulated curvature and Ivr2 transcript accumulation. Second, a transient gradient of free indole-3-acetic acid (IAA) across the pulvinus was apparent shortly after initiation of gravistimulation. This temporarily free IAA gradient appears to be important for differential cell elongation and Ivr2 transcript accumulation. This is based on the observation that N-1-naphthylphthalamic acid will not inhibit gravitropic responses when applied to pulvinus tissue after the free IAA gradient peak has occurred. Third, IAA alone can stimulate Ivr2 transcript accumulation in non-gravistimulated pulvini. The gravity- and IAA-stimulated increase in Ivr2 transcripts was sensitive to the protein synthesis inhibitor, cycloheximide. Based on these results, a two-phase model describing possible relationships between gravitropic curvature, IAA redistribution, and Ivr2 expression is presented.

  12. Gravity-stimulated changes in auxin and invertase gene expression in maize pulvinal cells.

    PubMed

    Long, Joanne C; Zhao, Wei; Rashotte, Aaron M; Muday, Gloria K; Huber, Steven C

    2002-02-01

    Maize (Zea mays) stem gravitropism involves differential elongation of cells within a highly specialized region, the stem internodal pulvinus. In the present study, we investigated factors that control gravitropic responses in this system. In the graviresponding pulvinus, hexose sugars (D-Glc and D-Fru) accumulated asymmetrically across the pulvinus. This correlated well with an asymmetric increase in acid invertase activity across the pulvinus. Northern analyses revealed asymmetric induction of one maize acid invertase gene, Ivr2, consistent with transcriptional regulation by gravistimulation. Several lines of evidence indicated that auxin redistribution, as a result of polar auxin transport, is necessary for gravity-stimulated Ivr2 transcript accumulation and differential cell elongation across the maize pulvinus. First, the auxin transport inhibitor, N-1-naphthylphthalamic acid, inhibited gravistimulated curvature and Ivr2 transcript accumulation. Second, a transient gradient of free indole-3-acetic acid (IAA) across the pulvinus was apparent shortly after initiation of gravistimulation. This temporarily free IAA gradient appears to be important for differential cell elongation and Ivr2 transcript accumulation. This is based on the observation that N-1-naphthylphthalamic acid will not inhibit gravitropic responses when applied to pulvinus tissue after the free IAA gradient peak has occurred. Third, IAA alone can stimulate Ivr2 transcript accumulation in non-gravistimulated pulvini. The gravity- and IAA-stimulated increase in Ivr2 transcripts was sensitive to the protein synthesis inhibitor, cycloheximide. Based on these results, a two-phase model describing possible relationships between gravitropic curvature, IAA redistribution, and Ivr2 expression is presented. PMID:11842162

  13. Gravity-Stimulated Changes in Auxin and Invertase Gene Expression in Maize Pulvinal Cells1

    PubMed Central

    Long, Joanne C.; Zhao, Wei; Rashotte, Aaron M.; Muday, Gloria K.; Huber, Steven C.

    2002-01-01

    Maize (Zea mays) stem gravitropism involves differential elongation of cells within a highly specialized region, the stem internodal pulvinus. In the present study, we investigated factors that control gravitropic responses in this system. In the graviresponding pulvinus, hexose sugars (d-Glc and d-Fru) accumulated asymmetrically across the pulvinus. This correlated well with an asymmetric increase in acid invertase activity across the pulvinus. Northern analyses revealed asymmetric induction of one maize acid invertase gene, Ivr2, consistent with transcriptional regulation by gravistimulation. Several lines of evidence indicated that auxin redistribution, as a result of polar auxin transport, is necessary for gravity-stimulated Ivr2 transcript accumulation and differential cell elongation across the maize pulvinus. First, the auxin transport inhibitor, N-1-naphthylphthalamic acid, inhibited gravistimulated curvature and Ivr2 transcript accumulation. Second, a transient gradient of free indole-3-acetic acid (IAA) across the pulvinus was apparent shortly after initiation of gravistimulation. This temporarily free IAA gradient appears to be important for differential cell elongation and Ivr2 transcript accumulation. This is based on the observation that N-1-naphthylphthalamic acid will not inhibit gravitropic responses when applied to pulvinus tissue after the free IAA gradient peak has occurred. Third, IAA alone can stimulate Ivr2 transcript accumulation in non-gravistimulated pulvini. The gravity- and IAA-stimulated increase in Ivr2 transcripts was sensitive to the protein synthesis inhibitor, cycloheximide. Based on these results, a two-phase model describing possible relationships between gravitropic curvature, IAA redistribution, and Ivr2 expression is presented. PMID:11842162

  14. Randomly Detected Genetically Modified (GM) Maize (Zea mays L.) near a Transport Route Revealed a Fragile 45S rDNA Phenotype

    PubMed Central

    Waminal, Nomar Espinosa; Ryu, Ki Hyun; Choi, Sun-Hee; Kim, Hyun Hee

    2013-01-01

    Monitoring of genetically modified (GM) crops has been emphasized to prevent their potential effects on the environment and human health. Monitoring of the inadvertent dispersal of transgenic maize in several fields and transport routes in Korea was carried out by qualitative multiplex PCR, and molecular analyses were conducted to identify the events of the collected GM maize. Cytogenetic investigations through fluorescence in situ hybridization (FISH) of the GM maize were performed to check for possible changes in the 45S rDNA cluster because this cluster was reported to be sensitive to replication and transcription stress. Three GM maize kernels were collected from a transport route near Incheon port, Korea, and each was found to contain NK603, stacked MON863 x NK603, and stacked NK603 x MON810 inserts, respectively. Cytogenetic analysis of the GM maize containing the stacked NK603 x MON810 insert revealed two normal compact 5S rDNA signals, but the 45S rDNA showed a fragile phenotype, demonstrating a “beads-on-a-string” fragmentation pattern, which seems to be a consequence of genetic modification. Implications of the 45S rDNA cluster fragility in GM maize are also discussed. PMID:24040165

  15. Novel role of ZmaNAC36 in co-expression of starch synthetic genes in maize endosperm.

    PubMed

    Zhang, Junjie; Chen, Jiang; Yi, Qiang; Hu, Yufeng; Liu, Hanmei; Liu, Yinghong; Huang, Yubi

    2014-02-01

    Starch is an essential commodity that is widely used as food, feed, fuel and in industry. However, its mechanism of synthesis is not fully understood, especially in terms of the expression and regulation of the starch synthetic genes. It was reported that the starch synthetic genes were co-expressed during maize endosperm development; however, the mechanism of the co-expression was not reported. In this paper, the ZmaNAC36 gene was amplified by homology-based cloning, and its expression vector was constructed for transient expression. The nuclear localization, transcriptional activation and target sites of the ZmaNAC36 protein were identified. The expression profile of ZmaNAC36 showed that it was strongly expressed in the maize endosperm and was co-expressed with most of the starch synthetic genes. Moreover, the expressions of many starch synthesis genes in the endosperm were upregulated when ZmaNAC36 was transiently overexpressed. All our results indicated that NAC36 might be a transcription factor and play a potential role in the co-expression of starch synthetic genes in the maize endosperm. PMID:24235061

  16. Testing Potential Effects of Maize Expressing the Bacillus thuringiensis Cry1Ab Endotoxin (Bt Maize) on Mycorrhizal Fungal Communities via DNA- and RNA-Based Pyrosequencing and Molecular Fingerprinting

    PubMed Central

    Kuramae, Eiko E.; Hillekens, Remy; de Hollander, Mattias; Kiers, E. Toby; Röling, Wilfred F. M.; Kowalchuk, George A.; van der Heijden, Marcel G. A.

    2012-01-01

    The cultivation of genetically modified (GM) crops has increased significantly over the last decades. However, concerns have been raised that some GM traits may negatively affect beneficial soil biota, such as arbuscular mycorrhizal fungi (AMF), potentially leading to alterations in soil functioning. Here, we test two maize varieties expressing the Bacillus thuringiensis Cry1Ab endotoxin (Bt maize) for their effects on soil AM fungal communities. We target both fungal DNA and RNA, which is new for AM fungi, and we use two strategies as an inclusive and robust way of detecting community differences: (i) 454 pyrosequencing using general fungal rRNA gene-directed primers and (ii) terminal restriction fragment length polymorphism (T-RFLP) profiling using AM fungus-specific markers. Potential GM-induced effects were compared to the normal natural variation of AM fungal communities across 15 different agricultural fields. AM fungi were found to be abundant in the experiment, accounting for 8% and 21% of total recovered DNA- and RNA-derived fungal sequences, respectively, after 104 days of plant growth. RNA- and DNA-based sequence analyses yielded most of the same AM fungal lineages. Our research yielded three major conclusions. First, no consistent differences were detected between AM fungal communities associated with GM plants and non-GM plants. Second, temporal variation in AMF community composition (between two measured time points) was bigger than GM trait-induced variation. Third, natural variation of AMF communities across 15 agricultural fields in The Netherlands, as well as within-field temporal variation, was much higher than GM-induced variation. In conclusion, we found no indication that Bt maize cultivation poses a risk for AMF. PMID:22885748

  17. Testing potential effects of maize expressing the Bacillus thuringiensis Cry1Ab endotoxin (Bt maize) on mycorrhizal fungal communities via DNA- and RNA-based pyrosequencing and molecular fingerprinting.

    PubMed

    Verbruggen, Erik; Kuramae, Eiko E; Hillekens, Remy; de Hollander, Mattias; Kiers, E Toby; Röling, Wilfred F M; Kowalchuk, George A; van der Heijden, Marcel G A

    2012-10-01

    The cultivation of genetically modified (GM) crops has increased significantly over the last decades. However, concerns have been raised that some GM traits may negatively affect beneficial soil biota, such as arbuscular mycorrhizal fungi (AMF), potentially leading to alterations in soil functioning. Here, we test two maize varieties expressing the Bacillus thuringiensis Cry1Ab endotoxin (Bt maize) for their effects on soil AM fungal communities. We target both fungal DNA and RNA, which is new for AM fungi, and we use two strategies as an inclusive and robust way of detecting community differences: (i) 454 pyrosequencing using general fungal rRNA gene-directed primers and (ii) terminal restriction fragment length polymorphism (T-RFLP) profiling using AM fungus-specific markers. Potential GM-induced effects were compared to the normal natural variation of AM fungal communities across 15 different agricultural fields. AM fungi were found to be abundant in the experiment, accounting for 8% and 21% of total recovered DNA- and RNA-derived fungal sequences, respectively, after 104 days of plant growth. RNA- and DNA-based sequence analyses yielded most of the same AM fungal lineages. Our research yielded three major conclusions. First, no consistent differences were detected between AM fungal communities associated with GM plants and non-GM plants. Second, temporal variation in AMF community composition (between two measured time points) was bigger than GM trait-induced variation. Third, natural variation of AMF communities across 15 agricultural fields in The Netherlands, as well as within-field temporal variation, was much higher than GM-induced variation. In conclusion, we found no indication that Bt maize cultivation poses a risk for AMF. PMID:22885748

  18. Temporal small RNA transcriptome profiling unraveled partitioned miRNA expression in developing maize endosperms between reciprocal crosses.

    PubMed

    Xin, Mingming; Yang, Guanghui; Yao, Yingyin; Peng, Huiru; Hu, Zhaorong; Sun, Qixin; Wang, Xiangfeng; Ni, Zhongfu

    2015-01-01

    In angiosperms, the endosperm nurtures the embryo and provides nutrients for seed germination. To identify the expression pattern of small interfering RNA in the developing maize endosperm, we have performed high-throughput small RNA transcriptome sequencing of kernels at 0, 3, and 5 days after pollination (DAP) and endosperms at 7, 10, and 15 DAP using B73 and Mo17 reciprocal crosses in previous study. Here, we further explored these small RNA-seq data to investigate the potential roles of miRNAs in regulating the gene expression process. In total, 57 conserved miRNAs and 18 novel miRNAs were observed highly expressed in maize endosperm. Temporal expression profiling indicated that these miRNAs exhibited dynamic and partitioned expression patterns at different developmental stages between maize reciprocal crosses, and quantitative RT-PCR results further confirmed our observation. In addition, we found a subset of distinct tandem miRNAs are generated from a single stem-loop structure in maize that might be conserved in monocots. Furthermore, a SNP variation of Zma-miR408-5p at 11th base position was characterized between B73 and Mo17 which might lead to completely different functions in repressing targets. More interestingly, Zma-miR408-5p exhibited B73-biased expression pattern in the B73 and Mo17 reciprocal hybrid endosperms at 7, 10, and 15 DAP according to the reads abundance with SNPs and CAPS experiment. Together, this study suggests that miRNA plays a crucial role in regulating endosperm development, and exhibited distinct expression patterns in developing endosperm between maize reciprocal crosses. PMID:26442057

  19. Event-specific detection of seven genetically modified soybean and maizes using multiplex-PCR coupled with oligonucleotide microarray.

    PubMed

    Xu, Jia; Zhu, Shuifang; Miao, Haizhen; Huang, Wensheng; Qiu, Minyan; Huang, Yan; Fu, Xuping; Li, Yao

    2007-07-11

    With the increasing development of genetically modified organism (GMO) detection techniques, the polymerase chain reaction (PCR) technique has been the mainstay for GMO detection. An oligonucleotide microarray is a glass chip to the surface of which an array of oligonucleotides was fixed as spots, each containing numerous copies of a sequence-specific probe that is complementary to a gene of interest. So it is used to detect ten or more targets synchronously. In this research, an event-specific detection strategy based on the unique and specific integration junction sequences between the host plant genome DNA and the integrated gene is being developed for its high specificity using multiplex-PCR together with oligonucleotide microarray. A commercial GM soybean (GTS 40-3-2) and six GM maize events (MON810, MON863, Bt176, Bt11, GA21, and T25) were detected by this method. The results indicate that it is a suitable method for the identification of these GM soybean and maizes. PMID:17559227

  20. Dosage effect of high-amylose modifier gene(s) on the starch structure of maize amylose-extender mutant.

    PubMed

    Jiang, Hongxin; Campbell, Mark; Wu, Yusheng; Du, Shuangkui; Srichuwong, Sathaporn; Jane, Jay-Lin

    2015-01-21

    The objective of this study was to investigate how dosages of high-amylose modifier (HAM) gene(s) affected the structure of maize amylose extender (ae) mutant starch. GEMS-0067 (G), a homozygous mutant of ae and the HAM gene(s), and H99ae (H), an ae single mutant, were self-pollinated or inter-crossed to produce maize endosperms of G/G, G/H, H/G, and H/H with 3, 2, 1, and 0 doses of HAM gene(s), respectively. Endosperm starch was fractionated into amylopectin, amylose, and intermediate component (IC) of large and small molecular weights using 1-butanol precipitation of amylose followed by gel-permeation chromatography. Increases in the dosage of HAM gene(s) from 0 to 3 decreased the amylopectin content. The HAM-gene dosage significantly changed the branch chain-length of small-molecular-weight IC, but had little effect on the branch chain-length distributions of amylopectin and large-molecular-weight IC and the molecular structure of amylose. PMID:25495144

  1. Dynamic expression of imprinted genes associates with maternally controlled nutrient allocation during maize endosperm development.

    PubMed

    Xin, Mingming; Yang, Ruolin; Li, Guosheng; Chen, Hao; Laurie, John; Ma, Chuang; Wang, Dongfang; Yao, Yingyin; Larkins, Brian A; Sun, Qixin; Yadegari, Ramin; Wang, Xiangfeng; Ni, Zhongfu

    2013-09-01

    In angiosperms, the endosperm provides nutrients for embryogenesis and seed germination and is the primary tissue where gene imprinting occurs. To identify the imprintome of early developing maize (Zea mays) endosperm, we performed high-throughput transcriptome sequencing of whole kernels at 0, 3, and 5 d after pollination (DAP) and endosperms at 7, 10, and 15 DAP, using B73 by Mo17 reciprocal crosses. We observed gradually increased expression of paternal transcripts in 3- and 5-DAP kernels. In 7-DAP endosperm, the majority of the genes tested reached a 2:1 maternal versus paternal ratio, suggesting that paternal genes are nearly fully activated by 7 DAP. A total of 116, 234, and 63 genes exhibiting parent-specific expression were identified at 7, 10, and 15 DAP, respectively. The largest proportion of paternally expressed genes was at 7 DAP, mainly due to the significantly deviated parental allele expression ratio of these genes at this stage, while nearly 80% of the maternally expressed genes (MEGs) were specific to 10 DAP and were primarily attributed to sharply increased expression levels compared with the other stages. Gene ontology enrichment analysis of the imprinted genes suggested that 10-DAP endosperm-specific MEGs are involved in nutrient uptake and allocation and the auxin signaling pathway, coincident with the onset of starch and storage protein accumulation. PMID:24058158

  2. Nucleotide sequence and expression of a maize H1 histone cDNA.

    PubMed Central

    Razafimahatratra, P; Chaubet, N; Philipps, G; Gigot, C

    1991-01-01

    The first complete amino acid sequence of a H1 histone of a monocotyledonous plant was deduced from a cDNA isolated from a maize library. The encoded H1 protein is 245 amino acid-long and shows the classical tripartite organization of this class of histones. The central globular region of 76 residues shows 60% sequence homology with H1 proteins from dicots but only 20% with the animal H1 proteins. However, several of the amino acids considered as being important in the structure of the nucleosome are conserved between this protein and its animal counterparts. The N-terminal region contains an equal number of acidic and basic residues which appears as a general feature of plant H1 proteins. The 124 residue long and highly basic C-terminal region contains a 7-fold repeated element KA/PKXA/PAKA/PK. Southern-blot hybridization showed that the H1 protein is encoded by a small multigene family. Highly homologous H1 gene families were also detected in the genomes of several more or less closely related plant species. The general expression pattern of these genes was not significantly different from that of these genes encoding the core-histones neither during germination nor in the different tissues of adult maize. Images PMID:1709276

  3. Integration of Ethylene and Jasmonic Acid Signaling Pathways in the Expression of Novel Maize Defense Protein Mir1-CP

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In plants, ethylene (ET) and jasmonate (JA) control the defense responses to multiple stressors, including insect predation. Among the defense proteins known to be regulated by ET, is maize insect resistance 1-cysteine protease (Mir1-CP). This protein is constitutively expressed in the insect resi...

  4. Field Evaluation of Arbuscular Mycorrhizal Fungal Colonization in Bacillus thuringiensis Toxin-Expressing (Bt) and Non-Bt Maize

    PubMed Central

    Cruzan, Mitchell B.; Rosenstiel, Todd N.

    2013-01-01

    The cultivation of genetically engineered Bacillus thuringiensis toxin-expressing (Bt) maize continues to increase worldwide, yet the effects of Bt crops on arbuscular mycorrhizal fungi (AMF) in soil are poorly understood. In this field experiment, we investigated the impact of seven different genotypes of Bt maize and five corresponding non-Bt parental cultivars on AMF and evaluated plant growth responses at three different physiological time points. Plants were harvested 60 days (active growth), 90 days (tasseling and starting to produce ears), and 130 days (maturity) after sowing, and data on plant growth responses and percent AMF colonization of roots at each harvest were collected. Spore abundance and diversity were also evaluated at the beginning and end of the field season to determine whether the cultivation of Bt maize had a negative effect on AMF propagules in the soil. Plant growth and AMF colonization did not differ between Bt and non-Bt maize at any harvest period, but AMF colonization was positively correlated with leaf chlorophyll content at the 130-day harvest. Cultivation of Bt maize had no effect on spore abundance and diversity in Bt versus non-Bt plots over one field season. Plot had the most significant effect on total spore counts, indicating spatial heterogeneity in the field. Although previous greenhouse studies demonstrated that AMF colonization was lower in some Bt maize lines, our field study did not yield the same results, suggesting that the cultivation of Bt maize may not have an impact on AMF in the soil ecosystem under field conditions. PMID:23624473

  5. Expression of cell wall related genes in basal and ear internodes of silking brown-midrib-3, caffeic acid O-methyltransferase (COMT) down-regulated, and normal maize plants

    PubMed Central

    Guillaumie, Sabine; Goffner, Deborah; Barbier, Odile; Martinant, Jean-Pierre; Pichon, Magalie; Barrière, Yves

    2008-01-01

    Background Silage maize is a major forage and energy resource for cattle feeding, and several studies have shown that lignin content and structure are the determining factors in forage maize feeding value. In maize, four natural brown-midrib mutants have modified lignin content, lignin structure and cell wall digestibility. The greatest lignin reduction and the highest cell wall digestibility were observed in the brown-midrib-3 (bm3) mutant, which is disrupted in the caffeic acid O-methyltransferase (COMT) gene. Results Expression of cell wall related genes was investigated in basal and ear internodes of normal, COMT antisens (AS225), and bm3 maize plants of the INRA F2 line. A cell wall macro-array was developed with 651 gene specific tags of genes specifically involved in cell wall biogenesis. When comparing basal (older lignifying) and ear (younger lignifying) internodes of the normal line, all genes known to be involved in constitutive monolignol biosynthesis had a higher expression in younger ear internodes. The expression of the COMT gene was heavily reduced, especially in the younger lignifying tissues of the ear internode. Despite the fact that AS225 transgene expression was driven only in sclerenchyma tissues, COMT expression was also heavily reduced in AS225 ear and basal internodes. COMT disruption or down-regulation led to differential expressions of a few lignin pathway genes, which were all over-expressed, except for a phenylalanine ammonia-lyase gene. More unexpectedly, several transcription factor genes, cell signaling genes, transport and detoxification genes, genes involved in cell wall carbohydrate metabolism and genes encoding cell wall proteins, were differentially expressed, and mostly over-expressed, in COMT-deficient plants. Conclusion Differential gene expressions in COMT-deficient plants highlighted a probable disturbance in cell wall assembly. In addition, the gene expressions suggested modified chronology of the different events leading

  6. Rapid visual detection of phytase gene in genetically modified maize using loop-mediated isothermal amplification method.

    PubMed

    Huang, Xin; Chen, Lili; Xu, Jiangmin; Ji, Hai-Feng; Zhu, Shuifang; Chen, Hongjun

    2014-08-01

    Transgenic maize plant expressing high phytase activity has been reported and approved by Chinese government in 2009. Here, we report a highly specific loop-mediated isothermal amplification (LAMP) method to detect the phytase gene in the GMO maize. The LAMP reaction takes less than 20min and the amplification is visible without gel electrophoresis. The detection sensitivity of the LAMP method is about 30 copies of phytase genomic DNA, which is 33.3 times greater than the conventional PCR method with gel electrophoresis. The quantitative detection results showed that the LAMP method has a good linear correlation between the DNA copy number and the associated Tt values over a large dynamic range of template concentration from 6×10(1) to 6×10(7) copies, with a quantification limit of 60 copies. Therefore, the LAMP method is visual, faster, and more sensitive, and does not need special equipment compared to traditional PCR technique, which is very useful for field tests and fast screening of GMO feeds. PMID:24629956

  7. Genome-Wide Identification of VQ Motif-Containing Proteins and their Expression Profiles Under Abiotic Stresses in Maize

    PubMed Central

    Song, Weibin; Zhao, Haiming; Zhang, Xiangbo; Lei, Lei; Lai, Jinsheng

    2016-01-01

    VQ motif-containing proteins play crucial roles in abiotic stress responses in plants. Recent studies have shown that some VQ proteins physically interact with WRKY transcription factors to activate downstream genes. In the present study, we identified and characterized genes encoding VQ motif-containing proteins using the most recent version of the maize genome sequence. In total, 61VQ genes were identified. In a cluster analysis, these genes clustered into nine groups together with their homologous genes in rice and Arabidopsis. Most of the VQ genes (57 out of 61 numbers) identified in maize were found to be single-copy genes. Analyses of RNA-seq data obtained using seedlings under long-term drought treatment showed that the expression levels of most ZmVQ genes (41 out of 61 members) changed during the drought stress response. Quantitative real-time PCR analyses showed that most of the ZmVQ genes were responsive to NaCl treatment. Also, approximately half of the ZmVQ genes were co-expressed with ZmWRKY genes. The identification of these VQ genes in the maize genome and knowledge of their expression profiles under drought and osmotic stresses will provide a solid foundation for exploring their specific functions in the abiotic stress responses of maize. PMID:26779214

  8. Differential expression of superoxide dismutase genes in aphid-stressed maize (Zea mays L.) seedlings.

    PubMed

    Sytykiewicz, Hubert

    2014-01-01

    The aim of this study was to compare the expression patterns of superoxide dismutase genes (sod2, sod3.4, sod9 and sodB) in seedling leaves of the Zea mays L. Tasty Sweet (susceptible) and Ambrozja (relatively resistant) cultivars infested with one of two hemipteran species, namely monophagous Sitobion avenae F. (grain aphid) or oligophagous Rhopalosiphum padi L. (bird cherry-oat aphid). Secondarily, aphid-elicited alternations in the antioxidative capacity towards DPPH (1,1-diphenyl-2-picrylhydrazyl) radical in insect-stressed plants were evaluated. Comprehensive comparison of expression profiles of the four sod genes showed that both insect species evoked significant upregulation of three genes sod2, sod3.4 and sod9). However, aphid infestation affected non-significant fluctuations in expression of sodB gene in seedlings of both maize genotypes. The highest levels of transcript accumulation occurred at 8 h (sod2 and sod3.4) or 24 h (sod9) post-infestation, and aphid-induced changes in the expression of sod genes were more dramatic in the Ambrozja cultivar than in the Tasty Sweet variety. Furthermore, bird cherry-oat aphid colonization had a more substantial impact on levels of DPPH radical scavenging activity in infested host seedlings than grain aphid colonization. Additionally, Ambrozja plants infested by either hemipteran species showed markedly lower antioxidative capacity compared with attacked Tasty Sweet plants. PMID:24722734

  9. Differential Expression of Superoxide Dismutase Genes in Aphid-Stressed Maize (Zea mays L.) Seedlings

    PubMed Central

    Sytykiewicz, Hubert

    2014-01-01

    The aim of this study was to compare the expression patterns of superoxide dismutase genes (sod2, sod3.4, sod9 and sodB) in seedling leaves of the Zea mays L. Tasty Sweet (susceptible) and Ambrozja (relatively resistant) cultivars infested with one of two hemipteran species, namely monophagous Sitobion avenae F. (grain aphid) or oligophagous Rhopalosiphum padi L. (bird cherry-oat aphid). Secondarily, aphid-elicited alternations in the antioxidative capacity towards DPPH (1,1-diphenyl-2-picrylhydrazyl) radical in insect-stressed plants were evaluated. Comprehensive comparison of expression profiles of the four sod genes showed that both insect species evoked significant upregulation of three genes sod2, sod3.4 and sod9). However, aphid infestation affected non-significant fluctuations in expression of sodB gene in seedlings of both maize genotypes. The highest levels of transcript accumulation occurred at 8 h (sod2 and sod3.4) or 24 h (sod9) post-infestation, and aphid-induced changes in the expression of sod genes were more dramatic in the Ambrozja cultivar than in the Tasty Sweet variety. Furthermore, bird cherry-oat aphid colonization had a more substantial impact on levels of DPPH radical scavenging activity in infested host seedlings than grain aphid colonization. Additionally, Ambrozja plants infested by either hemipteran species showed markedly lower antioxidative capacity compared with attacked Tasty Sweet plants. PMID:24722734

  10. Priming maize resistance by its neighbors: activating 1,4-benzoxazine-3-ones synthesis and defense gene expression to alleviate leaf disease

    PubMed Central

    Ding, Xupo; Yang, Min; Huang, Huichuan; Chuan, Youcong; He, Xiahong; Li, Chengyun; Zhu, Youyong; Zhu, Shusheng

    2015-01-01

    Plant disease can be effectively suppressed in intercropping systems. Our previous study demonstrated that neighboring maize plants can restrict the spread of soil-borne pathogens of pepper plants by secreting defense compounds into the soil. However, whether maize plant can receive benefits from its neighboring pepper plants in an intercropping system is little attention. We examined the effects of maize roots treated with elicitors from the pepper pathogen Phytophthora capsici and pepper root exudates on the synthesis of 1,4-benzoxazine-3-ones (BXs), the expression of defense-related genes in maize, and their ability to alleviate the severity of southern corn leaf blight (SCLB) caused by Bipolaris maydis. We found that SCLB was significantly reduced after the above treatments. The contents of 1,4-benzoxazine-3-ones (BXs: DIBOA, DIMBOA, and MBOA) and the expression levels of BX synthesis and defense genes in maize roots and shoots were up-regulated. DIMBOA and MBOA effectively inhibited the mycelium growth of Bipolaris maydis at physiological concentrations in maize shoots. Further studies suggested that the defense related pathways or genes in maize roots and shoots were activated by elicitors from the P. capsici or pepper root exudates. In conclusion, maize increased the levels of BXs and defense gene expression both in roots and shoots after being triggered by root exudates and pathogen from neighboring pepper plants, eventually enhancing its resistance. PMID:26528303

  11. Involvement of maize Dof zinc finger proteins in tissue-specific and light-regulated gene expression.

    PubMed Central

    Yanagisawa, S; Sheen, J

    1998-01-01

    Dof is a novel family of plant proteins that share a unique and highly conserved DNA binding domain with one C2-C2 zinc finger motif. Although multiple Dof proteins associated with diverse gene promoters have recently been identified in a variety of plants, their physiological functions and regulation remain elusive. In maize, Dof1 (MNB1a) is constitutively expressed in leaves, stems, and roots, whereas the closely related Dof2 is expressed mainly in stems and roots. Here, by using a maize leaf protoplast transient assay, we show that Dof1 is a transcriptional activator, whereas Dof2 can act as a transcriptional repressor. Thus, differential expression of Dof1 and Dof2 may permit leaf-specific gene expression. Interestingly, in vivo analyses showed that although DNA binding activity of Dof1 is regulated by light-dependent development, its transactivation activity and nuclear localization are not. Moreover, in vivo transcription and in vitro electrophoretic mobility shift assays revealed that Dof1 can interact specifically with the maize C4 phosphoenolpyruvate carboxylase gene promoter and enhance its promoter activity, which displays a light-regulated expression pattern matching Dof1 activity. We propose that the evolutionarily conserved Dof proteins can function as transcriptional activators or repressors of tissue-specific and light-regulated gene expression in plants. PMID:9477573

  12. Ionic liquids as novel solvents for biosynthesis of octenyl succinic anhydride-modified waxy maize starch.

    PubMed

    Li, Dandan; Zhang, Xiwen; Tian, Yaoqi

    2016-05-01

    Biosynthesis of octenyl succinic anhydride (OSA) starch was investigated using ionic liquids (ILs) as reaction media. Waxy maize starch was pretreated in 1-butyl-3-methylimidazolium chlorine and then esterified with OSA in 1-octyl-3-methylimidazolium nitrate by using Novozyme 435 as catalyst. The degree of substitution of OSA starch reached 0.0130 with 5 wt% starch concentration and 1 wt% lipase dosage based on ILs weight at 50 °C for 3h. The formation of OSA starch was confirmed by fourier transform infrared spectroscopy. Scanning electron microscopy and X-ray diffraction revealed that the morphology and crystal structure of starch were significantly destroyed. Thermogravimetric analysis showed that esterification decreased the thermal stability of starch. The successful lipase-catalyzed synthesis of OSA starch in ILs suggests that ILs are potential replacement of traditional organic solvents for starch ester biosynthesis. PMID:26797225

  13. Analyses of Expressed Sequence Tags from the Maize Foliar Pathogen Cercospora Zeae-Maydis Identifing Novel Genes expressed during Vegetative, Infectious, & Reproductive Growth

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fungus Cercospora zeae-maydis is an aggressive foliar pathogen of maize that causes substantial yield losses annually throughout the western hemisphere. To learn more about the molecular regulation of pathogenesis in C. zeae-maydis, we generated a collection of expressed sequence tags (ESTs) and...

  14. Expression Patterns of Genes Involved in Ascorbate-Glutathione Cycle in Aphid-Infested Maize (Zea mays L.) Seedlings

    PubMed Central

    Sytykiewicz, Hubert

    2016-01-01

    Reduced forms of ascorbate (AsA) and glutathione (GSH) are among the most important non-enzymatic foliar antioxidants in maize (Zea mays L.). The survey was aimed to evaluate impact of bird cherry-oat aphid (Rhopalosiphum padi L.) or grain aphid (Sitobion avenae F.) herbivory on expression of genes related to ascorbate-glutathione (AsA-GSH) cycle in seedlings of six maize varieties (Ambrozja, Nana, Tasty Sweet, Touran, Waza, Złota Karłowa), differing in resistance to the cereal aphids. Relative expression of sixteen maize genes encoding isoenzymes of ascorbate peroxidase (APX1, APX2, APX3, APX4, APX5, APX6, APX7), monodehydroascorbate reductase (MDHAR1, MDHAR2, MDHAR3, MDHAR4), dehydroascorbate reductase (DHAR1, DHAR2, DHAR3) and glutathione reductase (GR1, GR2) was quantified. Furthermore, effect of hemipterans’ attack on activity of APX, MDHAR, DHAR and GR enzymes, and the content of reduced and oxidized ascorbate and glutathione in maize plants were assessed. Seedling leaves of more resistant Z. mays varieties responded higher elevations in abundance of target transcripts. In addition, earlier and stronger aphid-triggered changes in activity of APX, MDHAR, DHAR and GR enzymes, and greater modulations in amount of the analyzed antioxidative metabolites were detected in foliar tissues of highly resistant Ambrozja genotype in relation to susceptible Tasty Sweet plants. PMID:26907270

  15. Expression Patterns of Genes Involved in Ascorbate-Glutathione Cycle in Aphid-Infested Maize (Zea mays L.) Seedlings.

    PubMed

    Sytykiewicz, Hubert

    2016-01-01

    Reduced forms of ascorbate (AsA) and glutathione (GSH) are among the most important non-enzymatic foliar antioxidants in maize (Zea mays L.). The survey was aimed to evaluate impact of bird cherry-oat aphid (Rhopalosiphum padi L.) or grain aphid (Sitobion avenae F.) herbivory on expression of genes related to ascorbate-glutathione (AsA-GSH) cycle in seedlings of six maize varieties (Ambrozja, Nana, Tasty Sweet, Touran, Waza, Złota Karłowa), differing in resistance to the cereal aphids. Relative expression of sixteen maize genes encoding isoenzymes of ascorbate peroxidase (APX1, APX2, APX3, APX4, APX5, APX6, APX7), monodehydroascorbate reductase (MDHAR1, MDHAR2, MDHAR3, MDHAR4), dehydroascorbate reductase (DHAR1, DHAR2, DHAR3) and glutathione reductase (GR1, GR2) was quantified. Furthermore, effect of hemipterans' attack on activity of APX, MDHAR, DHAR and GR enzymes, and the content of reduced and oxidized ascorbate and glutathione in maize plants were assessed. Seedling leaves of more resistant Z. mays varieties responded higher elevations in abundance of target transcripts. In addition, earlier and stronger aphid-triggered changes in activity of APX, MDHAR, DHAR and GR enzymes, and greater modulations in amount of the analyzed antioxidative metabolites were detected in foliar tissues of highly resistant Ambrozja genotype in relation to susceptible Tasty Sweet plants. PMID:26907270

  16. Multiplex quantification of 12 European Union authorized genetically modified maize lines with droplet digital polymerase chain reaction.

    PubMed

    Dobnik, David; Spilsberg, Bjørn; Bogožalec Košir, Alexandra; Holst-Jensen, Arne; Žel, Jana

    2015-08-18

    Presence of genetically modified organisms (GMO) in food and feed products is regulated in many countries. The European Union (EU) has implemented a threshold for labeling of products containing more than 0.9% of authorized GMOs per ingredient. As the number of GMOs has increased over time, standard-curve based simplex quantitative polymerase chain reaction (qPCR) analyses are no longer sufficiently cost-effective, despite widespread use of initial PCR based screenings. Newly developed GMO detection methods, also multiplex methods, are mostly focused on screening and detection but not quantification. On the basis of droplet digital PCR (ddPCR) technology, multiplex assays for quantification of all 12 EU authorized GM maize lines (per April first 2015) were developed. Because of high sequence similarity of some of the 12 GM targets, two separate multiplex assays were needed. In both assays (4-plex and 10-plex), the transgenes were labeled with one fluorescence reporter and the endogene with another (GMO concentration = transgene/endogene ratio). It was shown that both multiplex assays produce specific results and that performance parameters such as limit of quantification, repeatability, and trueness comply with international recommendations for GMO quantification methods. Moreover, for samples containing GMOs, the throughput and cost-effectiveness is significantly improved compared to qPCR. Thus, it was concluded that the multiplex ddPCR assays could be applied for routine quantification of 12 EU authorized GM maize lines. In case of new authorizations, the events can easily be added to the existing multiplex assays. The presented principle of quantitative multiplexing can be applied to any other domain. PMID:26169291

  17. Temporal patterns of gene expression in developing maize endosperm identified through transcriptome sequencing.

    PubMed

    Li, Guosheng; Wang, Dongfang; Yang, Ruolin; Logan, Kyle; Chen, Hao; Zhang, Shanshan; Skaggs, Megan I; Lloyd, Alan; Burnett, William J; Laurie, John D; Hunter, Brenda G; Dannenhoffer, Joanne M; Larkins, Brian A; Drews, Gary N; Wang, Xiangfeng; Yadegari, Ramin

    2014-05-27

    Endosperm is a filial structure resulting from a second fertilization event in angiosperms. As an absorptive storage organ, endosperm plays an essential role in support of embryo development and seedling germination. The accumulation of carbohydrate and protein storage products in cereal endosperm provides humanity with a major portion of its food, feed, and renewable resources. Little is known regarding the regulatory gene networks controlling endosperm proliferation and differentiation. As a first step toward understanding these networks, we profiled all mRNAs in the maize kernel and endosperm at eight successive stages during the first 12 d after pollination. Analysis of these gene sets identified temporal programs of gene expression, including hundreds of transcription-factor genes. We found a close correlation of the sequentially expressed gene sets with distinct cellular and metabolic programs in distinct compartments of the developing endosperm. The results constitute a preliminary atlas of spatiotemporal patterns of endosperm gene expression in support of future efforts for understanding the underlying mechanisms that control seed yield and quality. PMID:24821765

  18. Over-expression of the cucumber expansin gene (Cs-EXPA1) in transgenic maize seed for cellulose deconstruction.

    PubMed

    Yoon, Sangwoong; Devaiah, Shivakumar P; Choi, Seo-Eun; Bray, Jeff; Love, Robert; Lane, Jeffrey; Drees, Carol; Howard, John H; Hood, Elizabeth E

    2016-04-01

    Plant cell wall degradation into fermentable sugars by cellulases is one of the greatest barriers to biofuel production. Expansin protein loosens the plant cell wall by opening up the complex of cellulose microfibrils and polysaccharide matrix components thereby increasing its accessibility to cellulases. We over-expressed cucumber expansin in maize kernels to produce enough protein to assess its potential to serve as an industrial enzyme for applications particularly in biomass conversion. We used the globulin-1 embryo-preferred promoter to express the cucumber expansin gene in maize seed. Expansin protein was targeted to one of three sub-cellular locations: the cell wall, the vacuole, or the endoplasmic reticulum (ER). To assess the level of expansin accumulation in seeds of transgenic kernels, a high throughput expansin assay was developed. The highest expressing plants were chosen and enriched crude expansin extract from those plants was tested for synergistic effects with cellulase on several lignocellulosic substrates. Activity of recombinant cucumber expansin from transgenic kernels was confirmed on these pretreated substrates. The best transgenic lines (ER-targeted) can now be used for breeding to increase expansin expression for use in the biomass conversion industry. Results of these experiments show the success of expansin over-expression and accumulation in transgenic maize seed without negative impact on growth and development and confirm its synergistic effect with cellulase on deconstruction of complex cell wall substrates. PMID:26712321

  19. Detection of nonauthorized genetically modified organisms using differential quantitative polymerase chain reaction: application to 35S in maize.

    PubMed

    Cankar, Katarina; Chauvensy-Ancel, Valérie; Fortabat, Marie-Noelle; Gruden, Kristina; Kobilinsky, André; Zel, Jana; Bertheau, Yves

    2008-05-15

    Detection of nonauthorized genetically modified organisms (GMOs) has always presented an analytical challenge because the complete sequence data needed to detect them are generally unavailable although sequence similarity to known GMOs can be expected. A new approach, differential quantitative polymerase chain reaction (PCR), for detection of nonauthorized GMOs is presented here. This method is based on the presence of several common elements (e.g., promoter, genes of interest) in different GMOs. A statistical model was developed to study the difference between the number of molecules of such a common sequence and the number of molecules identifying the approved GMO (as determined by border-fragment-based PCR) and the donor organism of the common sequence. When this difference differs statistically from zero, the presence of a nonauthorized GMO can be inferred. The interest and scope of such an approach were tested on a case study of different proportions of genetically modified maize events, with the P35S promoter as the Cauliflower Mosaic Virus common sequence. The presence of a nonauthorized GMO was successfully detected in the mixtures analyzed and in the presence of (donor organism of P35S promoter). This method could be easily transposed to other common GMO sequences and other species and is applicable to other detection areas such as microbiology. PMID:18346452

  20. Development and validation of an event-specific quantitative PCR method for genetically modified maize MIR162.

    PubMed

    Takabatake, Reona; Masubuchi, Tomoko; Futo, Satoshi; Minegishi, Yasutaka; Noguchi, Akio; Kondo, Kazunari; Teshima, Reiko; Kurashima, Takeyo; Mano, Junichi; Kitta, Kazumi

    2014-01-01

    A novel real-time PCR-based analytical method was developed for the event-specific quantification of a genetically modified (GM) maize event, MIR162. We first prepared a standard plasmid for MIR162 quantification. The conversion factor (Cf) required to calculate the genetically modified organism (GMO) amount was empirically determined for two real-time PCR instruments, the Applied Biosystems 7900HT (ABI7900) and the Applied Biosystems 7500 (ABI7500) for which the determined Cf values were 0.697 and 0.635, respectively. To validate the developed method, a blind test was carried out in an interlaboratory study. The trueness and precision were evaluated as the bias and reproducibility of relative standard deviation (RSDr). The determined biases were less than 25% and the RSDr values were less than 20% at all evaluated concentrations. These results suggested that the limit of quantitation of the method was 0.5%, and that the developed method would thus be suitable for practical analyses for the detection and quantification of MIR162. PMID:25743383

  1. Impact of reagent infiltration time on reaction patterns and pasting properties of modified maize and wheat starches.

    PubMed

    Hong, Jung Sun; BeMiller, James N; Huber, Kerry C

    2016-10-20

    The impact of granular and molecular reaction patterns on modified starch properties was investigated as a function of the length of time allowed for reagent to infiltrate starch granules. A fluorescent reagent [5-(4,6-dichlorotriazinyl)aminofluorescein] was dispersed in aqueous normal maize or wheat starch slurries (35%, w/v) for 0, 5, 10, 30, or 60min, after which reaction was initiated by increasing the pH to 11.5 and allowing reaction to proceed for 3h. With increasing lengths of infiltration, the reaction became increasingly homogeneous within the granule interior (matrix) and the AM:AP reactivity ratio increased (wheat starch), as assessed by confocal laser scanning microscopy (CLSM) and size-exclusion chromatography (refractive index and fluorescence detection), respectively. A longer reagent infiltration time also led to a more inhibited (i.e., cross-linked) pasting viscosity, suggesting that both granular and/or molecular reaction patterns were altered by varied reagent infiltration times to ultimately impact modified starch properties. PMID:27474633

  2. Identification of 7 stress-related NAC transcription factor members in maize (Zea mays L.) and characterization of the expression pattern of these genes.

    PubMed

    Lu, Min; Sun, Qing-Peng; Zhang, Deng-Feng; Wang, Tian-Yu; Pan, Jin-Bao

    2015-06-26

    NAC proteins are plant-specific transcription factors that play essential roles in plant development and various abiotic stress responses. A comprehensive analysis of maize NAC genes was performed in this study. A total of 157 non-redundant maize NAC genes including seven membrane-bound members were identified and found to be unevenly distributed on 10 maize chromosomes. Motif composition analysis indicated that the maize NAC proteins share three relatively conserved motifs in the NAC domain within the N-terminal region. Phylogenetic analysis of 157 maize NAC proteins accompanied by 117 NAC proteins from Arabidopsis and 151 from rice were presented. The NAC proteins evaluated were divided into two large groups including 18 subgroups. Gene duplication analysis indicated that gene loss occurred during maize evolution. Seven NAC members that belong to the same clade of maize NAC domain genes were isolated, and overlapping expression patterns were observed under various abiotic stresses, including low temperature, high salinity and dehydration, and phytohormone abscisic acid treatments. This suggested that NAC members function as stress-responsive transcription factors in ABA-dependent signaling pathways. Relatively higher expression levels of these selected maize NAC genes were detected in roots. The stress responsive NAC genes may have applications in molecular breeding to improve crop stress tolerance. PMID:25937463

  3. Enhanced Virus Resistance in Transgenic Maize Expressing a dsRNA-Specific Endoribonuclease Gene from E. coli

    PubMed Central

    Liu, He; Tian, Lanzhi; Zhang, Aihong; Zhang, Yanjing; Shi, Lindan; Guo, Bihong; Xu, Jin; Duan, Xifei; Wang, Xianbing; Han, Chenggui; Miao, Hongqin; Yu, Jialin; Li, Dawei

    2013-01-01

    Maize rough dwarf disease (MRDD), caused by several Fijiviruses in the family Reoviridae, is a global disease that is responsible for substantial yield losses in maize. Although some maize germplasm have low levels of polygenic resistance to MRDD, highly resistant cultivated varieties are not available for agronomic field production in China. In this work, we have generated transgenic maize lines that constitutively express rnc70, a mutant E. coli dsRNA-specific endoribonuclease gene. Transgenic lines were propagated and screened under field conditions for 12 generations. During three years of evaluations, two transgenic lines and their progeny were challenged with Rice black-streaked dwarf virus (RBSDV), the causal agent of MRDD in China, and these plants exhibited reduced levels of disease severity. In two normal years of MRDD abundance, both lines were more resistant than non-transgenic plants. Even in the most serious MRDD year, six out of seven progeny from one line were resistant, whereas non-transgenic plants were highly susceptible. Molecular approaches in the T12 generation revealed that the rnc70 transgene was integrated and expressed stably in transgenic lines. Under artificial conditions permitting heavy virus inoculation, the T12 progeny of two highly resistant lines had a reduced incidence of MRDD and accumulation of RBSDV in infected plants. In addition, we confirmed that the RNC70 protein could bind directly to RBSDV dsRNA in vitro. Overall, our data show that RNC70-mediated resistance in transgenic maize can provide efficient protection against dsRNA virus infection. PMID:23593318

  4. Organ-specific gene expression in maize: The P-wr allele. Final report, August 15, 1993--August 14, 1996

    SciTech Connect

    Peterson, T.A.

    1997-06-01

    The ultimate aim of our work is to understand how a regulatory gene produces a specific pattern of gene expression during plant development. Our model is the P-wr gene of maize, which produces a distinctive pattern of pigmentation of maize floral organs. We are investigating this system using a combination of classical genetic and molecular approaches. Mechanisms of organ-specific gene expression are a subject of intense research interest, as it is the operation of these mechanisms during eukaryotic development which determine the characteristics of each organism Allele-specific expression has been characterized in only a few other plant genes. In maize, organ-specific pigmentation regulated by the R, B, and Pl genes is achieved by differential transcription of functionally conserved protein coding sequences. Our studies point to a strikingly different mechanism of organ-specific gene expression, involving post-transcriptional regulation of the regulatory P gene. The novel pigmentation pattern of the P-wr allele is associated with differences in the encoded protein. Furthermore, the P-wr gene itself is present as a unique tandemly amplified structure, which may affect its transcriptional regulation.

  5. Nitrogen transporter and assimilation genes exhibit developmental stage-selective expression in maize (Zea mays L.) associated with distinct cis-acting promoter motifs

    PubMed Central

    Liseron-Monfils, Christophe; Bi, Yong-Mei; Downs, Gregory S; Wu, Wenqing; Signorelli, Tara; Lu, Guangwen; Chen, Xi; Bondo, Eddie; Zhu, Tong; Lukens, Lewis N; Colasanti, Joseph; Rothstein, Steven J; Raizada, Manish N

    2013-01-01

    Nitrogen is considered the most limiting nutrient for maize (Zea mays L.), but there is limited understanding of the regulation of nitrogen-related genes during maize development. An Affymetrix 82K maize array was used to analyze the expression of ≤ 46 unique nitrogen uptake and assimilation probes in 50 maize tissues from seedling emergence to 31 d after pollination. Four nitrogen-related expression clusters were identified in roots and shoots corresponding to, or overlapping, juvenile, adult, and reproductive phases of development. Quantitative real time PCR data was consistent with the existence of these distinct expression clusters. Promoters corresponding to each cluster were screened for over-represented cis-acting elements. The 8-bp distal motif of the Arabidopsis 43-bp nitrogen response element (NRE) was over-represented in nitrogen-related maize gene promoters. This conserved motif, referred to here as NRE43-d8, was previously shown to be critical for nitrate-activated transcription of nitrate reductase (NIA1) and nitrite reductase (NIR1) by the NIN-LIKE PROTEIN 6 (NLP6) in Arabidopsis. Here, NRE43-d8 was over-represented in the promoters of maize nitrate and ammonium transporter genes, specifically those that showed peak expression during early-stage vegetative development. This result predicts an expansion of the NRE-NLP6 regulon and suggests that it may have a developmental component in maize. We also report leaf expression of putative orthologs of nitrite transporters (NiTR1), a transporter not previously reported in maize. We conclude by discussing how each of the four transcriptional modules may be responsible for the different nitrogen uptake and assimilation requirements of leaves and roots at different stages of maize development. PMID:24270626

  6. Isolation, characterization, and expression analyses of tryptophan aminotransferase genes in a maize dek18 mutant

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The dek18 mutant of maize has decreased auxin content in kernels. Molecular and functional characterization of this mutant line offers the possibility to better understand auxin biology in maize seed development. Seeds of the dek18 mutants are smaller compared to wild type seeds and the vegetative d...

  7. Seed-specific expression of the wheat puroindoline genes improves maize wet milling yields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The texture of maize (Zea mays L.) seeds is important to seed processing properties, and soft dent maize is preferred for both wet-milling and livestock feed applications. The puroindoline genes (Pina and Pinb) are the functional components of the wheat (Triticum aestivum L.) hardness locus and tog...

  8. Enhanced pest resistance of maize leaves expressing monocot crop plant derived ribosome inactivating protein and agglutinin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although many insect resistance genes have been identified, the number of studies examining their effects in combination using transgenic systems is limited. We introduced a construct into maize containing the coding sequence for maize ribosome inactivating protein (MRIP), wheat germ agglutinin (WGA...

  9. Annotation and computational analysis of maize proteome and gene expression datasets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Characterization of the transcriptome and proteome of the developing maize ear under different conditions has the potential to reveal the fundamental processes that confer resistance in some cell lines. We have previously reported the development of the PepIdent database of translated ESTs for maiz...

  10. Effects of Chemically Modified Messenger RNA on Protein Expression.

    PubMed

    Li, Bin; Luo, Xiao; Dong, Yizhou

    2016-03-16

    Chemically modified nucleotides play significant roles in the effectiveness of mRNA translation. Here, we describe the synthesis of two sets of chemically modified mRNAs [encoding firefly Luciferase (FLuc) and enhanced green fluorescent protein (eGFP), respectively], evaluation of protein expression, and correlation analysis of expression level under various conditions. The results indicate that chemical modifications of mRNAs are able to significantly improve protein expression, which is dependent on cell types and coding sequences. Moreover, eGFP mRNAs with N1-methylpseudouridine (me(1)ψ), 5-methoxyuridine (5moU), and pseudouridine (ψ) modifications ranked top three in cell lines tested. Interestingly, 5moU-modified eGFP mRNA was more stable than other eGFP mRNAs. Consequently, me(1)ψ, 5moU, and ψ are promising nucleotides for chemical modification of mRNAs. PMID:26906521

  11. Temporal Shift of Circadian-Mediated Gene Expression and Carbon Fixation Contributes to Biomass Heterosis in Maize Hybrids

    PubMed Central

    Song, Qingxin; Juenger, Thomas E.

    2016-01-01

    Heterosis has been widely used in agriculture, but the molecular mechanism for this remains largely elusive. In Arabidopsis hybrids and allopolyploids, increased photosynthetic and metabolic activities are linked to altered expression of circadian clock regulators, including CIRCADIAN CLOCK ASSOCIATED1 (CCA1). It is unknown whether a similar mechanism mediates heterosis in maize hybrids. Here we report that higher levels of carbon fixation and starch accumulation in the maize hybrids are associated with altered temporal gene expression. Two maize CCA1 homologs, ZmCCA1a and ZmCCA1b, are diurnally up-regulated in the hybrids. Expressing ZmCCA1 complements the cca1 mutant phenotype in Arabidopsis, and overexpressing ZmCCA1b disrupts circadian rhythms and biomass heterosis. Furthermore, overexpressing ZmCCA1b in maize reduced chlorophyll content and plant height. Reduced height stems from reduced node elongation but not total node number in both greenhouse and field conditions. Phenotypes are less severe in the field than in the greenhouse, suggesting that enhanced light and/or metabolic activities in the field can compensate for altered circadian regulation in growth vigor. Chromatin immunoprecipitation-sequencing (ChIP-seq) analysis reveals a temporal shift of ZmCCA1-binding targets to the early morning in the hybrids, suggesting that activation of morning-phased genes in the hybrids promotes photosynthesis and growth vigor. This temporal shift of ZmCCA1-binding targets correlated with nonadditive and additive gene expression in early and late stages of seedling development. These results could guide breeding better hybrid crops to meet the growing demand in food and bioenergy. PMID:27467757

  12. Expression and functional analysis of genes encoding cytokinin receptor-like histidine kinase in maize (Zea mays L.).

    PubMed

    Wang, Bo; Chen, Yanhong; Guo, Baojian; Kabir, Muhammad Rezaul; Yao, Yingyin; Peng, Huiru; Xie, Chaojie; Zhang, Yirong; Sun, Qixin; Ni, Zhongfu

    2014-08-01

    Cytokinin signaling is vital for plant growth and development which function via the two-component system (TCS). As one of the key component of TCS, transmembrane histidine kinases (HK) are encoded by a small gene family in plants. In this study, we focused on expression and functional analysis of cytokinin receptor-like HK genes (ZmHK) in maize. Firstly, bioinformatics analysis revealed that seven cloned ZmHK genes have different expression patterns during maize development. Secondly, ectopic expression by CaMV35S promoter in Arabidopsis further revealed that functional differentiation exists among these seven members. Among them, the ZmHK1a2-OX transgenic line has the lowest germination rate in the dark, ZmHK1-OX and ZmHK2a2-OX can delay leaf senescence, and seed size of ZmHK1-OX, ZmHK1a2-OX, ZmHK2-OX, ZmHK3b-OX and ZmHK2a2-OX was obviously reduced as compared to wild type. Additionally, ZmHK genes play opposite roles in shoot and root development; all ZmHK-OX transgenic lines display obvious shorter root length and reduced number of lateral roots, but enhanced shoot development compared with the wild type. Most notably, Arabidopsis response regulator ARR5 gene was up-regulated in ZmHK1-OX, ZmHK1a2-OX, ZmHK2-OX, ZmHK3b-OX and ZmHK2a2-OX as compared to wild type. Although the causal link between ZmHK genes and cytokinin signaling pathway is still an area to be further elucidated, these findings reflected that the diversification of ZmHK genes expression patterns and functions occurred in the course of maize evolution, indicating that some ZmHK genes might play different roles during maize development. PMID:24585212

  13. Temporal Shift of Circadian-Mediated Gene Expression and Carbon Fixation Contributes to Biomass Heterosis in Maize Hybrids.

    PubMed

    Ko, Dae Kwan; Rohozinski, Dominica; Song, Qingxin; Taylor, Samuel H; Juenger, Thomas E; Harmon, Frank G; Chen, Z Jeffrey

    2016-07-01

    Heterosis has been widely used in agriculture, but the molecular mechanism for this remains largely elusive. In Arabidopsis hybrids and allopolyploids, increased photosynthetic and metabolic activities are linked to altered expression of circadian clock regulators, including CIRCADIAN CLOCK ASSOCIATED1 (CCA1). It is unknown whether a similar mechanism mediates heterosis in maize hybrids. Here we report that higher levels of carbon fixation and starch accumulation in the maize hybrids are associated with altered temporal gene expression. Two maize CCA1 homologs, ZmCCA1a and ZmCCA1b, are diurnally up-regulated in the hybrids. Expressing ZmCCA1 complements the cca1 mutant phenotype in Arabidopsis, and overexpressing ZmCCA1b disrupts circadian rhythms and biomass heterosis. Furthermore, overexpressing ZmCCA1b in maize reduced chlorophyll content and plant height. Reduced height stems from reduced node elongation but not total node number in both greenhouse and field conditions. Phenotypes are less severe in the field than in the greenhouse, suggesting that enhanced light and/or metabolic activities in the field can compensate for altered circadian regulation in growth vigor. Chromatin immunoprecipitation-sequencing (ChIP-seq) analysis reveals a temporal shift of ZmCCA1-binding targets to the early morning in the hybrids, suggesting that activation of morning-phased genes in the hybrids promotes photosynthesis and growth vigor. This temporal shift of ZmCCA1-binding targets correlated with nonadditive and additive gene expression in early and late stages of seedling development. These results could guide breeding better hybrid crops to meet the growing demand in food and bioenergy. PMID:27467757

  14. Analysis of Gene Expression and Physiological Responses in Three Mexican Maize Landraces under Drought Stress and Recovery Irrigation

    PubMed Central

    Hayano-Kanashiro, Corina; Calderón-Vázquez, Carlos; Ibarra-Laclette, Enrique; Herrera-Estrella, Luis; Simpson, June

    2009-01-01

    Background Drought is one of the major constraints for plant productivity worldwide. Different mechanisms of drought-tolerance have been reported for several plant species including maize. However, the differences in global gene expression between drought-tolerant and susceptible genotypes and their relationship to physiological adaptations to drought are largely unknown. The study of the differences in global gene expression between tolerant and susceptible genotypes could provide important information to design more efficient breeding programs to produce maize varieties better adapted to water limiting conditions. Methodology/Principal Findings Changes in physiological responses and gene expression patterns were studied under drought stress and recovery in three Mexican maize landraces which included two drought tolerant (Cajete criollo and Michoacán 21) and one susceptible (85-2) genotypes. Photosynthesis, stomatal conductance, soil and leaf water potentials were monitored throughout the experiment and microarray analysis was carried out on transcripts obtained at 10 and 17 days following application of stress and after recovery irrigation. The two tolerant genotypes show more drastic changes in global gene expression which correlate with different physiological mechanisms of adaptation to drought. Differences in the kinetics and number of up- and down-regulated genes were observed between the tolerant and susceptible maize genotypes, as well as differences between the two tolerant genotypes. Interestingly, the most dramatic differences between the tolerant and susceptible genotypes were observed during recovery irrigation, suggesting that the tolerant genotypes activate mechanisms that allow more efficient recovery after a severe drought. Conclusions/Significance A correlation between levels of photosynthesis and transcription under stress was observed and differences in the number, type and expression levels of transcription factor families were also

  15. Interlaboratory validation of quantitative duplex real-time PCR method for screening analysis of genetically modified maize.

    PubMed

    Takabatake, Reona; Koiwa, Tomohiro; Kasahara, Masaki; Takashima, Kaori; Futo, Satoshi; Minegishi, Yasutaka; Akiyama, Hiroshi; Teshima, Reiko; Oguchi, Taichi; Mano, Junichi; Furui, Satoshi; Kitta, Kazumi

    2011-01-01

    To reduce the cost and time required to routinely perform the genetically modified organism (GMO) test, we developed a duplex quantitative real-time PCR method for a screening analysis simultaneously targeting an event-specific segment for GA21 and Cauliflower Mosaic Virus 35S promoter (P35S) segment [Oguchi et al., J. Food Hyg. Soc. Japan, 50, 117-125 (2009)]. To confirm the validity of the method, an interlaboratory collaborative study was conducted. In the collaborative study, conversion factors (Cfs), which are required to calculate the GMO amount (%), were first determined for two real-time PCR instruments, the ABI PRISM 7900HT and the ABI PRISM 7500. A blind test was then conducted. The limit of quantitation for both GA21 and P35S was estimated to be 0.5% or less. The trueness and precision were evaluated as the bias and reproducibility of the relative standard deviation (RSD(R)). The determined bias and RSD(R) were each less than 25%. We believe the developed method would be useful for the practical screening analysis of GM maize. PMID:21873818

  16. Direct extraction of genomic DNA from maize with aqueous ionic liquid buffer systems for applications in genetically modified organisms analysis.

    PubMed

    Gonzalez García, Eric; Ressmann, Anna K; Gaertner, Peter; Zirbs, Ronald; Mach, Robert L; Krska, Rudolf; Bica, Katharina; Brunner, Kurt

    2014-12-01

    To date, the extraction of genomic DNA is considered a bottleneck in the process of genetically modified organisms (GMOs) detection. Conventional DNA isolation methods are associated with long extraction times and multiple pipetting and centrifugation steps, which makes the entire procedure not only tedious and complicated but also prone to sample cross-contamination. In recent times, ionic liquids have emerged as innovative solvents for biomass processing, due to their outstanding properties for dissolution of biomass and biopolymers. In this study, a novel, easily applicable, and time-efficient method for the direct extraction of genomic DNA from biomass based on aqueous-ionic liquid solutions was developed. The straightforward protocol relies on extraction of maize in a 10 % solution of ionic liquids in aqueous phosphate buffer for 5 min at room temperature, followed by a denaturation step at 95 °C for 10 min and a simple filtration to remove residual biopolymers. A set of 22 ionic liquids was tested in a buffer system and 1-ethyl-3-methylimidazolium dimethylphosphate, as well as the environmentally benign choline formate, were identified as ideal candidates. With this strategy, the quality of the genomic DNA extracted was significantly improved and the extraction protocol was notably simplified compared with a well-established method. PMID:25381609

  17. Ninety-day oral toxicity studies on two genetically modified maize MON810 varieties in Wistar Han RCC rats (EU 7th Framework Programme project GRACE).

    PubMed

    Zeljenková, Dagmar; Ambrušová, Katarína; Bartušová, Mária; Kebis, Anton; Kovrižnych, Jevgenij; Krivošíková, Zora; Kuricová, Miroslava; Líšková, Aurélia; Rollerová, Eva; Spustová, Viera; Szabová, Elena; Tulinská, Jana; Wimmerová, Soňa; Levkut, Mikuláš; Révajová, Viera; Ševčíková, Zuzana; Schmidt, Kerstin; Schmidtke, Jörg; La Paz, Jose Luis; Corujo, Maria; Pla, Maria; Kleter, Gijs A; Kok, Esther J; Sharbati, Jutta; Hanisch, Carlos; Einspanier, Ralf; Adel-Patient, Karine; Wal, Jean-Michel; Spök, Armin; Pöting, Annette; Kohl, Christian; Wilhelm, Ralf; Schiemann, Joachim; Steinberg, Pablo

    2014-12-01

    The GMO Risk Assessment and Communication of Evidence (GRACE; www.grace-fp7.eu ) project is funded by the European Commission within the 7th Framework Programme. A key objective of GRACE is to conduct 90-day animal feeding trials, animal studies with an extended time frame as well as analytical, in vitro and in silico studies on genetically modified (GM) maize in order to comparatively evaluate their use in GM plant risk assessment. In the present study, the results of two 90-day feeding trials with two different GM maize MON810 varieties, their near-isogenic non-GM varieties and four additional conventional maize varieties are presented. The feeding trials were performed by taking into account the guidance for such studies published by the EFSA Scientific Committee in 2011 and the OECD Test Guideline 408. The results obtained show that the MON810 maize at a level of up to 33 % in the diet did not induce adverse effects in male and female Wistar Han RCC rats after subchronic exposure, independently of the two different genetic backgrounds of the event. PMID:25270621

  18. Competitive Expression of Endogenous Wheat CENH3 May Lead to Suppression of Alien ZmCENH3 in Transgenic Wheat × Maize Hybrids.

    PubMed

    Chen, Wei; Zhu, Qilin; Wang, Haiyan; Xiao, Jin; Xing, Liping; Chen, Peidu; Jin, Weiwei; Wang, Xiu-E

    2015-11-20

    Uniparental chromosome elimination in wheat × maize hybrid embryos is widely used in double haploid production of wheat. Several explanations have been proposed for this phenomenon, one of which is that the lack of cross-species CENH3 incorporation may act as a barrier to interspecies hybridization. However, it is unknown if this mechanism applies universally. To study the role of CENH3 in maize chromosome elimination of wheat × maize hybrid embryos, maize ZmCENH3 and wheat αTaCENH3-B driven by the constitutive CaMV35S promoter were transformed into wheat variety Yangmai 158. Five transgenic lines for ZmCENH3 and six transgenic lines for αTaCENH3-B were identified. RT-PCR analysis showed that the transgene could be transcribed at a low level in all ZmCENH3 transgenic lines, whereas transcription of endogenous wheat CENH3 was significantly up-regulated. Interestingly, the expression levels of both wheat CENH3 and ZmCENH3 in the ZmCENH3 transgenic wheat × maize hybrid embryos were higher than those in the non-transformed Yangmai 158 × maize hybrid embryos. This indicates that the alien ZmCENH3 in wheat may induce competitive expression of endogenous wheat CENH3, leading to suppression of ZmCENH3 over-expression. Eliminations of maize chromosomes in hybrid embryos of ZmCENH3 transgenic wheat × maize and Yangmai 158 × maize were compared by observations on micronuclei presence, by marker analysis using maize SSRs (simple sequence repeats), and by FISH (fluorescence in situ hybridization) using 45S rDNA as a probe. The results indicate that maize chromosome elimination events in the two crosses are not significantly different. Fusion protein ZmCENH3-YFP could not be detected in ZmCENH3 transgenic wheat by either Western blotting or immnunostaining, whereas accumulation and loading of the αTaCENH3-B-GFP fusion protein was normal in αTaCENH3-B transgenic lines. As ZmCENH3-YFP did not accumulate after AM114 treatment, we speculate that low levels of Zm

  19. A new PCR-CGE (size and color) method for simultaneous detection of genetically modified maize events.

    PubMed

    Nadal, Anna; Coll, Anna; La Paz, Jose-Luis; Esteve, Teresa; Pla, Maria

    2006-10-01

    We present a novel multiplex PCR assay for simultaneous detection of multiple transgenic events in maize. Initially, five PCR primers pairs specific to events Bt11, GA21, MON810, and NK603, and Zea mays L. (alcohol dehydrogenase) were included. The event specificity was based on amplification of transgene/plant genome flanking regions, i.e., the same targets as for validated real-time PCR assays. These short and similarly sized amplicons were selected to achieve high and similar amplification efficiency for all targets; however, its unambiguous identification was a technical challenge. We achieved a clear distinction by a novel CGE approach that combined the identification by size and color (CGE-SC). In one single step, all five targets were amplified and specifically labeled with three different fluorescent dyes. The assay was specific and displayed an LOD of 0.1% of each genetically modified organism (GMO). Therefore, it was adequate to fulfill legal thresholds established, e.g., in the European Union. Our CGE-SC based strategy in combination with an adequate labeling design has the potential to simultaneously detect higher numbers of targets. As an example, we present the detection of up to eight targets in a single run. Multiplex PCR-CGE-SC only requires a conventional sequencer device and enables automation and high throughput. In addition, it proved to be transferable to a different laboratory. The number of authorized GMO events is rapidly growing; and the acreage of genetically modified (GM) varieties cultivated and commercialized worldwide is rapidly increasing. In this context, our multiplex PCR-CGE-SC can be suitable for screening GM contents in food. PMID:16972302

  20. Allelic variants of the amylose extender mutation of maize demonstrate phenotypic variation in starch structure resulting from modified protein–protein interactions

    PubMed Central

    Liu, Fushan; Ahmed, Zaheer; Lee, Elizabeth A.; Donner, Elizabeth; Liu, Qiang; Ahmed, Regina; Morell, Matthew K.; Emes, Michael J.; Tetlow, Ian J.

    2012-01-01

    amylose extender (ae−) starches characteristically have modified starch granule morphology resulting from amylopectin with reduced branch frequency and longer glucan chains in clusters, caused by the loss of activity of the major starch branching enzyme (SBE), which in maize endosperm is SBEIIb. A recent study with ae− maize lacking the SBEIIb protein (termed ae1.1 herein) showed that novel protein–protein interactions between enzymes of starch biosynthesis in the amyloplast could explain the starch phenotype of the ae1.1 mutant. The present study examined an allelic variant of the ae− mutation, ae1.2, which expresses a catalytically inactive form of SBEIIb. The catalytically inactive SBEIIb in ae1.2 lacks a 28 amino acid peptide (Val272–Pro299) and is unable to bind to amylopectin. Analysis of starch from ae1.2 revealed altered granule morphology and physicochemical characteristics distinct from those of the ae1.1 mutant as well as the wild-type, including altered apparent amylose content and gelatinization properties. Starch from ae1.2 had fewer intermediate length glucan chains (degree of polymerization 16–20) than ae1.1. Biochemical analysis of ae1.2 showed that there were differences in the organization and assembly of protein complexes of starch biosynthetic enzymes in comparison with ae1.1 (and wild-type) amyloplasts, which were also reflected in the composition of starch granule-bound proteins. The formation of stromal protein complexes in the wild-type and ae1.2 was strongly enhanced by ATP, and broken by phosphatase treatment, indicating a role for protein phosphorylation in their assembly. Labelling experiments with [γ-32P]ATP showed that the inactive form of SBEIIb in ae1.2 was phosphorylated, both in the monomeric form and in association with starch synthase isoforms. Although the inactive SBEIIb was unable to bind starch directly, it was strongly associated with the starch granule, reinforcing the conclusion that its presence in the

  1. Root-expressed maize lipoxygenase 3 negatively regulates induced systemic resistance to Colletotrichum graminicola in shoots

    PubMed Central

    Constantino, Nasie N.; Mastouri, Fatemeh; Damarwinasis, Ramadhika; Borrego, Eli J.; Moran-Diez, Maria E.; Kenerley, Charley M.; Gao, Xiquan; Kolomiets, Michael V.

    2013-01-01

    We have previously reported that disruption of a maize root-expressed 9-lipoxygenase (9-LOX) gene, ZmLOX3, results in dramatic increase in resistance to diverse leaf and stalk pathogens. Despite evident economic significance of these findings, the mechanism behind this increased resistance remained elusive. In this study, we found that increased resistance of the lox3-4 mutants is due to constitutive activation of induced systemic resistance (ISR) signaling. We showed that ZmLOX3 lacked expression in leaves in response to anthracnose leaf blight pathogen Colletotrichum graminicola, but was expressed constitutively in the roots, thus, prompting our hypothesis: the roots of lox3-4 mutants are the source of increased resistance in leaves. Supporting this hypothesis, treatment of wild-type plants (WT) with xylem sap of lox3-4 mutant induced resistance to C. graminicola to the levels comparable to those observed in lox3-4 mutant. Moreover, treating mutants with the sap collected from WT plants partially restored the susceptibility to C. graminicola. lox3-4 mutants showed primed defense responses upon infection, which included earlier and greater induction of defense-related PAL and GST genes compared to WT. In addition to the greater expression of the octadecanoid pathway genes, lox3-4 mutant responded earlier and with a greater accumulation of H2O2 in response to C. graminicola infection or treatment with alamethicin. These findings suggest that lox3-4 mutants display constitutive ISR-like signaling. In support of this idea, root colonization by Trichoderma virens strain GV29-8 induced the same level of disease resistance in WT as the treatment with the mutant sap, but had no additional resistance effect in lox3-4 mutant. While treatment with T. virens GV29 strongly and rapidly suppressed ZmLOX3 expression in hydroponically grown WT roots, T. virens Δsml mutant, which is deficient in ISR induction, was unable to suppress expression of ZmLOX3, thus, providing genetic

  2. Event specific qualitative and quantitative polymerase chain reaction detection of genetically modified MON863 maize based on the 5'-transgene integration sequence.

    PubMed

    Yang, Litao; Xu, Songci; Pan, Aihu; Yin, Changsong; Zhang, Kewei; Wang, Zhenying; Zhou, Zhigang; Zhang, Dabing

    2005-11-30

    Because of the genetically modified organisms (GMOs) labeling policies issued in many countries and areas, polymerase chain reaction (PCR) methods were developed for the execution of GMO labeling policies, such as screening, gene specific, construct specific, and event specific PCR detection methods, which have become a mainstay of GMOs detection. The event specific PCR detection method is the primary trend in GMOs detection because of its high specificity based on the flanking sequence of the exogenous integrant. This genetically modified maize, MON863, contains a Cry3Bb1 coding sequence that produces a protein with enhanced insecticidal activity against the coleopteran pest, corn rootworm. In this study, the 5'-integration junction sequence between the host plant DNA and the integrated gene construct of the genetically modified maize MON863 was revealed by means of thermal asymmetric interlaced-PCR, and the specific PCR primers and TaqMan probe were designed based upon the revealed 5'-integration junction sequence; the conventional qualitative PCR and quantitative TaqMan real-time PCR detection methods employing these primers and probes were successfully developed. In conventional qualitative PCR assay, the limit of detection (LOD) was 0.1% for MON863 in 100 ng of maize genomic DNA for one reaction. In the quantitative TaqMan real-time PCR assay, the LOD and the limit of quantification were eight and 80 haploid genome copies, respectively. In addition, three mixed maize samples with known MON863 contents were detected using the established real-time PCR systems, and the ideal results indicated that the established event specific real-time PCR detection systems were reliable, sensitive, and accurate. PMID:16302741

  3. Impact of genetic structures on haploid genome-based quantification of genetically modified DNA: theoretical considerations, experimental data in MON 810 maize kernels (Zea mays L.) and some practical applications.

    PubMed

    Zhang, David; Corlet, Aurélie; Fouilloux, Stephane

    2008-06-01

    Real-time Polymerase Chain Reaction (PCR) based assays are widely used to estimate the content of genetically modified (GM) materials in food, feed and seed. It has been known that the genetic structures of the analyte can significantly influence the GM content expressed by the haploid genome (HG) % estimated using real-time PCR assays; this kind of influence is also understood as the impact of biological factors. The influence was first simulated at theoretical level using maize as a model. We then experimentally assessed the impact of biological factors on quantitative results, analysing by quantitative real-time PCR six maize MON 810 hybrid kernels with different genetic structures: (1) hemizygous from transgenic male parent, (2) hemizygous from transgenic female parent and (3) homozygous at the transgenic locus. The results obtained in the present study showed clear influences of biological factors on GM DNA quantification: 1% of GM materials by weight (wt) for the three genetic structures contained 0.39, 0.55 and 1.0% of GM DNA by HG respectively, from quantitative real-time PCR analyses. The relationships between GM wt% and GM HG% can be empirically established as: (1) in the case of the presence of a single GM trait: GM HG% = GM wt% x (0.5 +/- 0.167Y), where Y is the endosperm DNA content (%) in the total DNA of a maize kernel, (2) in the case of the presence of multiple GM traits: GM HG% = N x GM wt% x (0.5 +/- 0.167Y), where N is the number of GM traits (stacked or not) present in an unknown sample. This finding can be used by stakeholders related to GMO for empirical prediction from one unit of expression to another in the monitoring of seed and grain production chains. Practical equations have also been suggested for haploid copy number calculations, using hemizygous GM materials for calibration curves. PMID:17638110

  4. Development of insect resistant maize plants expressing a chitinase gene from the cotton leaf worm, Spodoptera littoralis.

    PubMed

    Osman, Gamal H; Assem, Shireen K; Alreedy, Rasha M; El-Ghareeb, Doaa K; Basry, Mahmoud A; Rastogi, Anshu; Kalaji, Hazem M

    2015-01-01

    Due to the importance of chitinolytic enzymes for insect, nematode and fungal growth, they are receiving attention concerning their development as biopesticides or chemical defense proteins in transgenic plants and as microbial biocontrol agents. Targeting chitin associated with the extracellular matrices or cell wall by insect chitinases may be an effective approach for controlling pest insects and pathogenic fungi. The ability of chitinases to attack and digest chitin in the peritrophic matrix or exoskeleton raises the possibility to use them as insect control method. In this study, an insect chitinase cDNA from cotton leaf worm (Spodoptera littoralis) has been synthesized. Transgenic maize plant system was used to improve its tolerance against insects. Insect chitinase transcripts and proteins were expressed in transgenic maize plants. The functional integrity and expression of chitinase in progenies of the transgenic plants were confirmed by insect bioassays. The bioassays using transgenic corn plants against corn borer (Sesamia cretica) revealed that ~50% of the insects reared on transgenic corn plants died, suggesting that transgenic maize plants have enhanced resistance against S. cretica. PMID:26658494

  5. Development of insect resistant maize plants expressing a chitinase gene from the cotton leaf worm, Spodoptera littoralis

    PubMed Central

    Osman, Gamal H.; Assem, Shireen K.; Alreedy, Rasha M.; El-Ghareeb, Doaa K.; Basry, Mahmoud A.; Rastogi, Anshu; Kalaji, Hazem M.

    2015-01-01

    Due to the importance of chitinolytic enzymes for insect, nematode and fungal growth, they are receiving attention concerning their development as biopesticides or chemical defense proteins in transgenic plants and as microbial biocontrol agents. Targeting chitin associated with the extracellular matrices or cell wall by insect chitinases may be an effective approach for controlling pest insects and pathogenic fungi. The ability of chitinases to attack and digest chitin in the peritrophic matrix or exoskeleton raises the possibility to use them as insect control method. In this study, an insect chitinase cDNA from cotton leaf worm (Spodoptera littoralis) has been synthesized. Transgenic maize plant system was used to improve its tolerance against insects. Insect chitinase transcripts and proteins were expressed in transgenic maize plants. The functional integrity and expression of chitinase in progenies of the transgenic plants were confirmed by insect bioassays. The bioassays using transgenic corn plants against corn borer (Sesamia cretica) revealed that ~50% of the insects reared on transgenic corn plants died, suggesting that transgenic maize plants have enhanced resistance against S. cretica. PMID:26658494

  6. Stress-induced and epigenetic-mediated maize transcriptome regulation study by means of transcriptome reannotation and differential expression analysis.

    PubMed

    Forestan, Cristian; Aiese Cigliano, Riccardo; Farinati, Silvia; Lunardon, Alice; Sanseverino, Walter; Varotto, Serena

    2016-01-01

    Plant's response and adaptation to abiotic stresses involve sophisticated genetic and epigenetic regulatory systems. To obtain a global view of molecular response to osmotic stresses, including the non-coding portion of genome, we conducted a total leaf transcriptome analysis on maize plants subjected to prolonged drought and salt stresses. Stress application to both B73 wild type and the epiregulator mutant rpd1-1/rmr6 allowed dissection of the epigenetic component of stress response. Coupling total RNA-Seq and transcriptome re-assembly we annotated thousands of new maize transcripts, together with 13,387 lncRNAs that may play critical roles in regulating gene expression. Differential expression analysis revealed hundreds of genes modulated by long-term stress application, including also many lncRNAs and transposons specifically induced by stresses. The amplitude and dynamic of the stress-modulated gene sets are very different between B73 and rpd1-1/rmr6 mutant plants, as result of stress-like effect on genome regulation caused by the mutation itself, which activates many stress-related genes even in control condition. The analyzed extensive set of total RNA-Seq data, together with the improvement of the transcriptome and the identification of the non-coding portion of the transcriptome give a revealing insight into the genetic and epigenetic mechanism responsible for maize molecular response to abiotic stresses. PMID:27461139

  7. Stress-induced and epigenetic-mediated maize transcriptome regulation study by means of transcriptome reannotation and differential expression analysis

    PubMed Central

    Forestan, Cristian; Aiese Cigliano, Riccardo; Farinati, Silvia; Lunardon, Alice; Sanseverino, Walter; Varotto, Serena

    2016-01-01

    Plant’s response and adaptation to abiotic stresses involve sophisticated genetic and epigenetic regulatory systems. To obtain a global view of molecular response to osmotic stresses, including the non-coding portion of genome, we conducted a total leaf transcriptome analysis on maize plants subjected to prolonged drought and salt stresses. Stress application to both B73 wild type and the epiregulator mutant rpd1-1/rmr6 allowed dissection of the epigenetic component of stress response. Coupling total RNA-Seq and transcriptome re-assembly we annotated thousands of new maize transcripts, together with 13,387 lncRNAs that may play critical roles in regulating gene expression. Differential expression analysis revealed hundreds of genes modulated by long-term stress application, including also many lncRNAs and transposons specifically induced by stresses. The amplitude and dynamic of the stress-modulated gene sets are very different between B73 and rpd1-1/rmr6 mutant plants, as result of stress-like effect on genome regulation caused by the mutation itself, which activates many stress-related genes even in control condition. The analyzed extensive set of total RNA-Seq data, together with the improvement of the transcriptome and the identification of the non-coding portion of the transcriptome give a revealing insight into the genetic and epigenetic mechanism responsible for maize molecular response to abiotic stresses. PMID:27461139

  8. Expression Profiling of the Maize Flavonoid Pathway Genes Controlled by Estradiol-Inducible Transcription Factors CRC and P

    PubMed Central

    Bruce, Wesley; Folkerts, Otto; Garnaat, Carl; Crasta, Oswald; Roth, Brad; Bowen, Ben

    2000-01-01

    To determine the scope of gene expression controlled by the maize transcription factors C1/R and P, which are responsible for activating flavonoid synthesis, we used GeneCalling, an open-ended, gel-based, mRNA-profiling technology, to analyze cell suspension lines of the maize inbred Black Mexican Sweet (BMS) that harbored estradiol-inducible versions of these factors. BMS cells were transformed with a continually expressed estrogen receptor/maize C1 activator domain fusion gene (ER–C1) and either a fusion of C1 and R (CRC), P, or luciferase genes regulated by a promoter containing four repeats of an estrogen receptor binding site. Increasing amounts of luciferase activity, anthocyanins, and flavan-4-ols were detected in the respective cell lines after the addition of estradiol. The expression of both known and novel genes was detected simultaneously in these BMS lines by profiling the mRNA isolated from replicate samples at 0, 6, and 24 hr after estradiol treatment. Numerous cDNA fragments were identified that showed a twofold or greater difference in abundance at 6 and 24 hr than at 0 hr. The cDNA fragments from the known flavonoid genes, except chalcone isomerase (chi1), were induced in the CRC-expressing line after hormone induction, whereas only the chalcone synthase (c2) and flavanone/dihydroflavonol reductase (a1) genes were induced in the P-expressing line, as was expected. Many novel cDNA fragments were also induced or repressed by lines expressing CRC alone, P alone, or both transcription factors in unique temporal patterns. The temporal differences and the evidence of repression indicate a more diverse set of regulatory controls by CRC or P than originally expected. GeneCalling analysis was successful in detecting members of complex metabolic pathways and uncovering novel genes that were either coincidentally regulated or directly involved in such pathways. PMID:10634908

  9. Selection of Suitable DNA Extraction Methods for Genetically Modified Maize 3272, and Development and Evaluation of an Event-Specific Quantitative PCR Method for 3272.

    PubMed

    Takabatake, Reona; Masubuchi, Tomoko; Futo, Satoshi; Minegishi, Yasutaka; Noguchi, Akio; Kondo, Kazunari; Teshima, Reiko; Kurashima, Takeyo; Mano, Junichi; Kitta, Kazumi

    2016-01-01

    A novel real-time PCR-based analytical method was developed for the event-specific quantification of a genetically modified (GM) maize, 3272. We first attempted to obtain genome DNA from this maize using a DNeasy Plant Maxi kit and a DNeasy Plant Mini kit, which have been widely utilized in our previous studies, but DNA extraction yields from 3272 were markedly lower than those from non-GM maize seeds. However, lowering of DNA extraction yields was not observed with GM quicker or Genomic-tip 20/G. We chose GM quicker for evaluation of the quantitative method. We prepared a standard plasmid for 3272 quantification. The conversion factor (Cf), which is required to calculate the amount of a genetically modified organism (GMO), was experimentally determined for two real-time PCR instruments, the Applied Biosystems 7900HT (the ABI 7900) and the Applied Biosystems 7500 (the ABI7500). The determined Cf values were 0.60 and 0.59 for the ABI 7900 and the ABI 7500, respectively. To evaluate the developed method, a blind test was conducted as part of an interlaboratory study. The trueness and precision were evaluated as the bias and reproducibility of the relative standard deviation (RSDr). The determined values were similar to those in our previous validation studies. The limit of quantitation for the method was estimated to be 0.5% or less, and we concluded that the developed method would be suitable and practical for detection and quantification of 3272. PMID:26936302

  10. Development of resistance to eCry3.1Ab-expressing transgenic maize in a laboratory-selected population of western corn rootworm (Coleoptera: Chrysomelidae).

    PubMed

    Frank, Daniel L; Zukoff, Anthony; Barry, Julie; Higdon, Matthew L; Hibbard, Bruce E

    2013-12-01

    A laboratory colony of western corn rootworm, Diabrotica virgifera virgifera LeConte, was selected for resistance to transgenic maize expressing the eCry3.1Ab protein. The selected colony was developed by rearing larvae on nonelite noncommercial Bt maize expressing the eCry3.1Ab protein. After four generations, selected and control colonies were screened on eCry3.1Ab-expressing and isoline maize using greenhouse experiments. There was a significant colony x maize pedigree interaction in terms of the number of larvae recovered. There was no significant difference in the number of larvae recovered from eCry3.1Ab-expressing and isoline maize for the selected colony, whereas this difference was significant for the control colony. There was not a significant colony x maize pedigree interaction in terms of root damage, or the number of beetles recovered, but the effect of maize pedigree was significant. After four and eight generations of selection, seedling bioassays were performed. Again, there was a significant colony x maize pedigree interaction in terms of the number of larvae recovered. After 11 generations of selection, larvae from the selected colony had higher LC50 values than the control colony when exposed to increasing concentrations of the eCry3.1Ab protein. The resistance ratio of the selected colony was 2.58. These data provide necessary information for understanding the potential for Bt resistance by western corn rootworm and underscores the need for insect resistance management plans for this pest. PMID:24498752

  11. Genome-wide identification, expression analysis of auxin-responsive GH3 family genes in maize (Zea mays L.) under abiotic stresses.

    PubMed

    Feng, Shangguo; Yue, Runqing; Tao, Sun; Yang, Yanjun; Zhang, Lei; Xu, Mingfeng; Wang, Huizhong; Shen, Chenjia

    2015-09-01

    Auxin is involved in different aspects of plant growth and development by regulating the expression of auxin-responsive family genes. As one of the three major auxin-responsive families, GH3 (Gretchen Hagen3) genes participate in auxin homeostasis by catalyzing auxin conjugation and bounding free indole-3-acetic acid (IAA) to amino acids. However, how GH3 genes function in responses to abiotic stresses and various hormones in maize is largely unknown. Here, the latest updated maize (Zea mays L.) reference genome sequence was used to characterize and analyze the ZmGH3 family genes from maize. The results showed that 13 ZmGH3 genes were mapped on five maize chromosomes (total 10 chromosomes). Highly diversified gene structures and tissue-specific expression patterns suggested the possibility of function diversification for these genes in response to environmental stresses and hormone stimuli. The expression patterns of ZmGH3 genes are responsive to several abiotic stresses (salt, drought and cadmium) and major stress-related hormones (abscisic acid, salicylic acid and jasmonic acid). Various environmental factors suppress auxin free IAA contents in maize roots suggesting that these abiotic stresses and hormones might alter GH3-mediated auxin levels. The responsiveness of ZmGH3 genes to a wide range of abiotic stresses and stress-related hormones suggested that ZmGH3s are involved in maize tolerance to environmental stresses. PMID:25557253

  12. Consumption of Bt Maize Pollen Expressing Cry1Ab or Cry3Bb1 Does Not Harm Adult Green Lacewings, Chrysoperla carnea (Neuroptera: Chrysopidae)

    PubMed Central

    Li, Yunhe; Meissle, Michael; Romeis, Jörg

    2008-01-01

    Adults of the common green lacewing, Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae), are prevalent pollen-consumers in maize fields. They are therefore exposed to insecticidal proteins expressed in the pollen of insect-resistant, genetically engineered maize varieties expressing Cry proteins derived from Bacillus thuringiensis (Bt). Laboratory experiments were conducted to evaluate the impact of Cry3Bb1 or Cry1Ab-expressing transgenic maize (MON 88017, Event Bt176) pollen on fitness parameters of adult C. carnea. Adults were fed pollen from Bt maize varieties or their corresponding near isolines together with sucrose solution for 28 days. Survival, pre-oviposition period, fecundity, fertility and dry weight were not different between Bt or non-Bt maize pollen treatments. In order to ensure that adults of C. carnea are not sensitive to the tested toxins independent from the plant background and to add certainty to the hazard assessment, adult C. carnea were fed with artificial diet containing purified Cry3Bb1 or Cry1Ab at about a 10 times higher concentration than in maize pollen. Artificial diet containing Galanthus nivalis agglutinin (GNA) was included as a positive control. No differences were found in any life-table parameter between Cry protein containing diet treatments and control diet. However, the pre-oviposition period, daily and total fecundity and dry weight of C. carnea were significantly negatively affected by GNA-feeding. In both feeding assays, the stability and bioactivity of Cry proteins in the food sources as well as the uptake by C. carnea was confirmed. These results show that adults of C. carnea are not affected by Bt maize pollen and are not sensitive to Cry1Ab and Cry3Bb1 at concentrations exceeding the levels in pollen. Consequently, Bt maize pollen consumption will pose a negligible risk to adult C. carnea. PMID:18682800

  13. Consumption of Bt maize pollen expressing Cry1Ab or Cry3Bb1 does not harm adult green Lacewings, Chrysoperla carnea (Neuroptera: Chrysopidae).

    PubMed

    Li, Yunhe; Meissle, Michael; Romeis, Jörg

    2008-01-01

    Adults of the common green lacewing, Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae), are prevalent pollen-consumers in maize fields. They are therefore exposed to insecticidal proteins expressed in the pollen of insect-resistant, genetically engineered maize varieties expressing Cry proteins derived from Bacillus thuringiensis (Bt). Laboratory experiments were conducted to evaluate the impact of Cry3Bb1 or Cry1Ab-expressing transgenic maize (MON 88017, Event Bt176) pollen on fitness parameters of adult C. carnea. Adults were fed pollen from Bt maize varieties or their corresponding near isolines together with sucrose solution for 28 days. Survival, pre-oviposition period, fecundity, fertility and dry weight were not different between Bt or non-Bt maize pollen treatments. In order to ensure that adults of C. carnea are not sensitive to the tested toxins independent from the plant background and to add certainty to the hazard assessment, adult C. carnea were fed with artificial diet containing purified Cry3Bb1 or Cry1Ab at about a 10 times higher concentration than in maize pollen. Artificial diet containing Galanthus nivalis agglutinin (GNA) was included as a positive control. No differences were found in any life-table parameter between Cry protein containing diet treatments and control diet. However, the pre-oviposition period, daily and total fecundity and dry weight of C. carnea were significantly negatively affected by GNA-feeding. In both feeding assays, the stability and bioactivity of Cry proteins in the food sources as well as the uptake by C. carnea was confirmed. These results show that adults of C. carnea are not affected by Bt maize pollen and are not sensitive to Cry1Ab and Cry3Bb1 at concentrations exceeding the levels in pollen. Consequently, Bt maize pollen consumption will pose a negligible risk to adult C. carnea. PMID:18682800

  14. [Effects of exogenous EBR and NO signal on antioxidant system and low response gene expression under cold stress on maize embryo].

    PubMed

    Ma, Jin-hu; Xing, Guo-fang; Yang, Xiao-huan; Wang, Yu-guo; Du, Hui-ling

    2015-05-01

    In this study, Xianyu 335, a maize hybrid, was used to investigate the effects of 24-Epibrassinolide (EBR, a synthetic BR) on antioxidant capacity and low-temperature response gene expression in maize embryo germination under low temperature (LT) stress. The germination rate of maize seeds under LT stress was not affected by EBR, but the seed activity index and seedling growth were improved. EBR increased the activities of some antioxidative enzymes including SOD, POD, CAT and GR, and the contents of non-enzymatic antioxidants, such as GSH and proline, and induced the accumulation of nitric oxide (NO). NO scavenging c-PTIO and NOS inhibitor L- NAME decreased but NO donor SNP increased the enzyme activities of CAT and POD, and the content of proline, indicating NO mediated the EBR-induced antioxidant capacity. The gene expression pattern analysis showed that the expression of P5CS1, CBF1, CBF3 and COR15a was induced by LT stress, and further increased by EBR treatment in maize embryo, while their expression was suppressed by c-PTIO and L-NAME, and improved by SNP, which implied LT-responsed genes were regulated by NO. These results demonstrated that NO was involved in the EBR-induced LT tolerance in maize embryo by modulating the antioxidative capacity and the expression of LT-responsive genes. PMID:26571659

  15. The regulation of gene expression in transformed maize aleurone and endosperm protoplasts. Analysis of promoter activity, intron enhancement, and mRNA untranslated regions on expression.

    PubMed Central

    Gallie, D R; Young, T E

    1994-01-01

    Gene expression in the aleurone and endosperm is highly regulated during both seed development and germination. Studies of alpha-amylase expression in the aleurone of barley (Hordeum vulgare) have generated the current paradigm for hormonal control of gene expression in germinating cereal grain. Gene expression studies in both the aleurone and endosperm tissues of maize (Zea mays) seed have been hampered because of a lack of an efficient transformation system. We report here the rapid isolation of protoplasts from maize aleurone and endosperm tissue, their transformation using polyethylene glycol or electroporation, and the regulation of gene expression in these cells. Adh1 promoter activity was reduced relative to the 35S promoter in aleurone and endosperm protoplasts compared to Black Mexican Sweet suspension cells in which it was nearly as strong as the 35S promoter. Intron-mediated stimulation of expression was substantially higher in transformed aleurone or endosperm protoplasts than in cell-suspension culture protoplasts, and the data suggest that the effect of an intron may be affected by cell type. To examine cytoplasmic regulation, the 5' and 3' untranslated regions from a barley alpha-amylase were fused to the firefly luciferase-coding region, and their effect on translation and mRNA stability was examined following the delivery of in vitro synthesized mRNA to aleurone and endosperm protoplasts. The alpha-amylase untranslated regions regulated translational efficiency in a tissue-specific manner, increasing translation in aleurone or endosperm protoplasts but not in maize or carrot cell-suspension protoplasts, in animal cells, or in in vitro translation lysates. PMID:7824660

  16. Microtubule-Associated Protein SBgLR Facilitates Storage Protein Deposition and Its Expression Leads to Lysine Content Increase in Transgenic Maize Endosperm

    PubMed Central

    Liu, Chen; Li, Shixue; Yue, Jing; Xiao, Wenhan; Zhao, Qian; Zhu, Dengyun; Yu, Jingjuan

    2015-01-01

    Maize (Zea mays) seed is deficient in protein and lysine content. Many studies have been made to improve the nutritional quality of maize seeds. Previously, we reported the role of a natural lysine-rich protein gene SBgLR in increasing protein and lysine content. However, how the SBgLR improves lysine and protein content remains unclear. Here, the reasons and possible mechanism for SBgLR in protein and lysine improvement have been analyzed and discussed. Through seed-specific expression of SBgLR, we obtained transgenic maize with the simultaneously increased lysine and protein contents. High-protein and high-lysine characters were stably inherited across generations. The expression of SBgLR in maize kernels increased the accumulation of both zeins and non-zein proteins. Transmission electron microscopy showed that the number of protein bodies (PBs) was increased obviously in SBgLR transgenic immature endosperms with the morphology and structure of PBs unchanged. The proteinaceous matrix was more abundant in transgenic mature endosperms under scanning electron microscopy. The stabilities of zein and lysine-rich non-zein genes were also increased in transgenic endosperms. Finally, the potential application of SBgLR in maize nutrient improvement was evaluated. This study shows that a cytoskeleton-associated protein has potential applicable value in crop nutrient improving, and provided a feasible strategy for improvement of maize grain quality. PMID:26703573

  17. Seed-Specific Expression of the Arabidopsis AtMAP18 Gene Increases both Lysine and Total Protein Content in Maize.

    PubMed

    Chang, Yujie; Shen, Erli; Wen, Liuying; Yu, Jingjuan; Zhu, Dengyun; Zhao, Qian

    2015-01-01

    Lysine is the most limiting essential amino acid for animal nutrition in maize grains. Expression of naturally lysine-rich protein genes can increase the lysine and protein contents in maize seeds. AtMAP18 from Arabidopsis thaliana encoding a microtubule-associated protein with high-lysine content was introduced into the maize genome with the seed-specific promoter F128. The protein and lysine contents of different transgenic offspring were increased prominently in the six continuous generations investigated. Expression of AtMAP18 increased both zein and non-zein protein in the transgenic endosperm. Compared with the wild type, more protein bodies were observed in the endosperm of transgenic maize. These results implied that, as a cytoskeleton binding protein, AtMAP18 facilitated the formation of protein bodies, which led to accumulation of both zein and non-zein proteins in the transgenic maize grains. Furthermore, F1 hybrid lines with high lysine, high protein and excellent agronomic traits were obtained by hybridizing T6 transgenic offspring with other wild type inbred lines. This article provides evidence supporting the use of cytoskeleton-associated proteins to improve the nutritional value of maize. PMID:26580206

  18. Microtubule-Associated Protein SBgLR Facilitates Storage Protein Deposition and Its Expression Leads to Lysine Content Increase in Transgenic Maize Endosperm.

    PubMed

    Liu, Chen; Li, Shixue; Yue, Jing; Xiao, Wenhan; Zhao, Qian; Zhu, Dengyun; Yu, Jingjuan

    2015-01-01

    Maize (Zea mays) seed is deficient in protein and lysine content. Many studies have been made to improve the nutritional quality of maize seeds. Previously, we reported the role of a natural lysine-rich protein gene SBgLR in increasing protein and lysine content. However, how the SBgLR improves lysine and protein content remains unclear. Here, the reasons and possible mechanism for SBgLR in protein and lysine improvement have been analyzed and discussed. Through seed-specific expression of SBgLR, we obtained transgenic maize with the simultaneously increased lysine and protein contents. High-protein and high-lysine characters were stably inherited across generations. The expression of SBgLR in maize kernels increased the accumulation of both zeins and non-zein proteins. Transmission electron microscopy showed that the number of protein bodies (PBs) was increased obviously in SBgLR transgenic immature endosperms with the morphology and structure of PBs unchanged. The proteinaceous matrix was more abundant in transgenic mature endosperms under scanning electron microscopy. The stabilities of zein and lysine-rich non-zein genes were also increased in transgenic endosperms. Finally, the potential application of SBgLR in maize nutrient improvement was evaluated. This study shows that a cytoskeleton-associated protein has potential applicable value in crop nutrient improving, and provided a feasible strategy for improvement of maize grain quality. PMID:26703573

  19. Seed-Specific Expression of the Arabidopsis AtMAP18 Gene Increases both Lysine and Total Protein Content in Maize

    PubMed Central

    Chang, Yujie; Shen, Erli; Wen, Liuying; Yu, Jingjuan; Zhu, Dengyun; Zhao, Qian

    2015-01-01

    Lysine is the most limiting essential amino acid for animal nutrition in maize grains. Expression of naturally lysine-rich protein genes can increase the lysine and protein contents in maize seeds. AtMAP18 from Arabidopsis thaliana encoding a microtubule-associated protein with high-lysine content was introduced into the maize genome with the seed-specific promoter F128. The protein and lysine contents of different transgenic offspring were increased prominently in the six continuous generations investigated. Expression of AtMAP18 increased both zein and non-zein protein in the transgenic endosperm. Compared with the wild type, more protein bodies were observed in the endosperm of transgenic maize. These results implied that, as a cytoskeleton binding protein, AtMAP18 facilitated the formation of protein bodies, which led to accumulation of both zein and non-zein proteins in the transgenic maize grains. Furthermore, F1 hybrid lines with high lysine, high protein and excellent agronomic traits were obtained by hybridizing T6 transgenic offspring with other wild type inbred lines. This article provides evidence supporting the use of cytoskeleton-associated proteins to improve the nutritional value of maize. PMID:26580206

  20. Maize variety and method of production

    DOEpatents

    Pauly, Markus; Hake, Sarah; Kraemer, Florian J

    2014-05-27

    The disclosure relates to a maize plant, seed, variety, and hybrid. More specifically, the disclosure relates to a maize plant containing a Cal-1 allele, whose expression results in increased cell wall-derived glucan content in the maize plant. The disclosure also relates to crossing inbreds, varieties, and hybrids containing the Cal-1 allele to produce novel types and varieties of maize plants.

  1. Development and Interlaboratory Validation of a Simple Screening Method for Genetically Modified Maize Using a ΔΔC(q)-Based Multiplex Real-Time PCR Assay.

    PubMed

    Noguchi, Akio; Nakamura, Kosuke; Sakata, Kozue; Sato-Fukuda, Nozomi; Ishigaki, Takumi; Mano, Junichi; Takabatake, Reona; Kitta, Kazumi; Teshima, Reiko; Kondo, Kazunari; Nishimaki-Mogami, Tomoko

    2016-04-19

    A number of genetically modified (GM) maize events have been developed and approved worldwide for commercial cultivation. A screening method is needed to monitor GM maize approved for commercialization in countries that mandate the labeling of foods containing a specified threshold level of GM crops. In Japan, a screening method has been implemented to monitor approved GM maize since 2001. However, the screening method currently used in Japan is time-consuming and requires generation of a calibration curve and experimental conversion factor (C(f)) value. We developed a simple screening method that avoids the need for a calibration curve and C(f) value. In this method, ΔC(q) values between the target sequences and the endogenous gene are calculated using multiplex real-time PCR, and the ΔΔC(q) value between the analytical and control samples is used as the criterion for determining analytical samples in which the GM organism content is below the threshold level for labeling of GM crops. An interlaboratory study indicated that the method is applicable independently with at least two models of PCR instruments used in this study. PMID:27010783

  2. Low-molecular weight protein profiling of genetically modified maize using fast liquid chromatography electrospray ionization and time-of-flight mass spectrometry.

    PubMed

    Koc, Anna; Cañuelo, Ana; Garcia-Reyes, Juan F; Molina-Diaz, Antonio; Trojanowicz, Marek

    2012-06-01

    In this work, the use of liquid chromatography coupled to electrospray time-of-flight mass spectrometry (LC-TOFMS) has been evaluated for the profiling of relatively low-molecular weight protein species in both genetically modified (GM) and non-GM maize. The proposed approach consisted of a straightforward sample fractionation with different water and ethanol-based buffer solutions followed by separation and detection of the protein species using liquid chromatography with a small particle size (1.8 μm) C(18) column and electrospray-time-of-flight mass spectrometry detection in the positive ionization mode. The fractionation of maize reference material containing different content of transgenic material (from 0 to 5% GM) led to five different fractions (albumins, globulins, zeins, zein-like glutelins, and glutelins), all of them containing different protein species (from 2 to 52 different species in each fraction). Some relevant differences in the quantity and types of protein species were observed in the different fractions of the reference material (with different GM contents) tested, thus revealing the potential use of the proposed approach for fast protein profiling and to detect tentative GMO markers in maize. PMID:22740254

  3. Root morphology and gene expression analysis in response to drought stress in maize (Zea mays)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water-deficit stress tolerance is a complex trait, and water deficit results in various physiological and chemical changes in maize (Zea mays L.) and exacerbates preharvest aflatoxin contamination. The objective of this study was to characterize the variations in morphology, physiology and gene expr...

  4. Transgenic maize plants expressing the Totivirus antifungal protein, KP4, are highly resistant to corn smut

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The corn smut fungus, Ustilago maydis, is a global pathogen responsible for extensive agricultural losses. Control of corn smut using traditional breeding has met with limited success because natural resistance to U. maydis is organ specific and involves numerous maize genes. Here, we present a tran...

  5. Tissue-specific expression of maize domestication and crop improvement loci

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The domestication of maize from its wild progenitors represents an opportunity to investigate the timing and genetic basis of morphological divergence resulting from artificial selection on target genes. We compared sequence diversity of 30 candidate selected and 15 reference loci between the three...

  6. In planta expression of A. cellulolyticus Cel5A endocellulase reduces cell wall recalcitrance in tobacco and maize

    PubMed Central

    2011-01-01

    The glycoside hydrolase family 5 endocellulase, E1 (Cel5A), from Acidothermus cellulolyticus was transformed into both Nicotiana tabacum and Zea mays with expression targeted to the cell wall under a constitutive promoter. Here we explore the possibility that in planta expression of endocellulases will allow these enzymes to access their substrates during cell wall construction, rendering cellulose more amenable to pretreatment and enzyme digestion. Tobacco and maize plants were healthy and developed normally compared with the wild type (WT). After thermochemical pretreatment and enzyme digestion, transformed plants were clearly more digestible than WT, requiring lower pretreatment severity to achieve comparable conversion levels. Furthermore, the decreased recalcitrance was not due to post-pretreatment residual E1 activity and could not be reproduced by the addition of exogenous E1 to the biomass prior to pretreatment, indicating that the expression of E1 during cell wall construction altered the inherent recalcitrance of the cell wall. PMID:21269444

  7. Molecular cloning, characterization and differential expression of novel phytocystatin gene during tropospheric ozone stress in maize (Zea mays) leaves.

    PubMed

    Ahmad, Rafiq; Zuily-Fodil, Yasmine; Passaquet, Chantal; Ali Khan, Sabaz; Repellin, Anne

    2015-03-01

    In this study, a full-length cDNA encoding a novel phytocystatin gene, designated CC14, was identified in maize leaves. The CC14 gene sequence reported in this study has been deposited in the GenBank database (accession number JF290478). The CC14 gene was cloned into an expression vector pET30 EK/LIC and was then transformed into Escherichia coli strain BL21 (DE3) pLysS to produce a recombinant CC14 protein. The recombinant protein was purified by nickel nitrilotriacetic acid affinity chromatography after induction with 1 mM IPTG. The purified CC14 protein was electrophoresed on SDS-PAGE and a protein 25 kDa in size was observed. Antiprotease activities of the purified recombinant CC14 protein against cysteine proteases and commercially available papain were tested. The results showed that CC14 purified protein suppressed 100% activity of papain and 57-86% plant cysteine protease activity. Moreover, an upregulation of CC14 gene expression was observed after 20 days of ozone stress in maize leaves. Together, these observations concurred to conclude that CC14 gene could potentially be used as a basis for the development of transgenic crops and natural pesticides that resist biotic and abiotic stresses. PMID:25613048

  8. A nitrate-inducible ferredoxin in maize roots. Genomic organization and differential expression of two nonphotosynthetic ferredoxin isoproteins.

    PubMed Central

    Matsumura, T; Sakakibara, H; Nakano, R; Kimata, Y; Sugiyama, T; Hase, T

    1997-01-01

    We have identified and characterized a nitrate-inducible ferredoxin (Fd) in maize (Zea mays L.) roots by structural analysis of the purified protein and by cloning of its cDNA and gene. In maize Fd isoproteins are encoded by a small multigene family, and the nitrate-inducible Fd was identified as a novel isoprotein, designated Fd VI, which differed from an Fd I to Fd V identified to date. In the roots of seedlings cultured without nitrate, Fd VI was undetectable. However, during the induction of the capacity for nitrate assimilation, the amount of Fd VI increased markedly within 24 h. Concurrently, the level of transcript for Fd VI increased, but more quickly, reaching a maximal level within 2 h with kinetics similar to those of nitrite reductase and Fd-NADP+ reductase. Fd III was constitutively expressed in roots, and no such changes at the protein and mRNA levels were observed during the nitrate induction. In the 5' flanking region of the gene for Fd VI only, we identified NIT-2 motifs, which are widely found in genes for enzymes related to nitrogen metabolism. These data indicate that Fd VI is co-induced with the previously characterized enzymes involved in nitrate assimilation, and they suggest that the novel Fd isoprotein, distinct from the constitutively expressed Fd, might play an important role as an electron carrier from NADPH to nitrite reductase and other Fd-dependent enzymes in root plastids. PMID:9193097

  9. Constitutive expression of pathogenesis-related proteins and antioxydant enzyme activities triggers maize resistance towards Fusarium verticillioides.

    PubMed

    Maschietto, Valentina; Lanubile, Alessandra; Leonardis, Silvana De; Marocco, Adriano; Paciolla, Costantino

    2016-08-01

    Fusarium verticillioides is a fungal pathogen of maize that causes ear rot and contaminates the grains with fumonisin mycotoxins. Breeding for resistance to Fusarium emerged as the most economic and environmentally safe strategy; therefore the discovery of resistant sources and effective molecular markers are a priority. Ears of resistant (CO441 and CO433) and susceptible (CO354 and CO389) maize lines were inoculated with F. verticillioides and the expression of pathogenesis-related (PR) genes (PR1, PR5, PRm3, PRm6) and genes that protect from oxidative stress (peroxidase, catalase, superoxide dismutase and ascorbate peroxidase) were evaluated in the kernels at 72h post inoculation. In addition, the oxidation level and the enzymatic activity of ascorbate-glutathione cycle, catalase, superoxide dismutase and cytosolic and wall peroxidases were investigated. The uninoculated kernels of the resistant lines showed higher gene expression and enzymatic activities, highlighting the key role of constitutive resistance in limiting pathogen attack. In contrast, the susceptible lines activated defensive genes only after pathogen inoculation, resulting in increased levels of H2O2 and lipid peroxidation, as well as lower enzymatic activities. The constitutive defenses observed in this study from seed could be profitably exploited to develop markers to speed up conventional breeding programs in the selection of resistant genotypes. PMID:27340858

  10. FUM Gene Expression Profile and Fumonisin Production by Fusarium verticillioides Inoculated in Bt and Non-Bt Maize

    PubMed Central

    Rocha, Liliana O.; Barroso, Vinícius M.; Andrade, Ludmila J.; Pereira, Gustavo H. A.; Ferreira-Castro, Fabiane L.; Duarte, Aildson P.; Michelotto, Marcos D.; Correa, Benedito

    2016-01-01

    This study aimed to determine the levels of fumonisins produced by Fusarium verticillioides and FUM gene expression on Bt (Bacillus thuringiensis) and non-Bt maize, post harvest, during different periods of incubation. Transgenic hybrids 30F35 YG, 2B710 Hx and their isogenic (30F35 and 2B710) were collected from the field and a subset of 30 samples selected for the experiments. Maize samples were sterilized by gamma radiation at a dose of 20 kGy. Samples were then inoculated with F. verticillioides and analyzed under controlled conditions of temperature and relative humidity for fumonisin B1 and B2 (FB1 and FB2) production and FUM1, FUM3, FUM6, FUM7, FUM8, FUM13, FUM14, FUM15, and FUM19 expression. 2B710 Hx and 30F35 YG kernel samples were virtually intact when compared to the non-Bt hybrids that came from the field. Statistical analysis showed that FB1 production was significantly lower in 30F35 YG and 2B710 Hx than in the 30F35 and 2B710 hybrids (P < 0.05). However, there was no statistical difference for FB2 production (P > 0.05). The kernel injuries observed in the non-Bt samples have possibly facilitated F. verticillioides penetration and promoted FB1 production under controlled conditions. FUM genes were expressed by F. verticillioides in all of the samples. However, there was indication of lower expression of a few FUM genes in the Bt hybrids; and a weak association between FB1 production and the relative expression of some of the FUM genes were observed in the 30F35 YG hybrid. PMID:26779158

  11. The application of laser microdissection to in planta gene expression profiling of the maize anthracnose stalk rot fungus Colletotrichum graminicola.

    PubMed

    Tang, Weihua; Coughlan, Sean; Crane, Edmund; Beatty, Mary; Duvick, Jon

    2006-11-01

    Laser microdissection (LM) offers a potential means for deep sampling of a fungal plant-pathogen transcriptome during the infection process using whole-genome DNA microarrays. The use of a fluorescent protein-expressing fungus can greatly facilitate the identification of fungal structures for LM sampling. However, fixation methods that preserve both tissue histology and protein fluorescence, and that also yield RNA of suitable quality for microarray applications, have not been reported. We developed a microwave-accelerated acetone fixation, paraffin-embedding method that fulfills these requirements and used it to prepare mature maize stalk tissues infected with an Anemonia majano cyan fluorescent protein-expressing isolate of the anthracnose stalk rot fungus Colletotrichum graminicola. We successfully used LM to isolate individual maize cells associated with C. graminicola hyphae at an early stage of infection. The LM-derived RNA, after two-round linear amplification, was of sufficient quality and quantity for global expression profiling using a fungal microarray. Comparing replicated LM samples representing an early stage of stalk cell infection with samples from in vitro-germinated conidia, we identified 437 and 370 C. graminicola genes showing significant up- or downregulation, respectively. We confirmed the differential expression of several representative transcripts by quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) and documented extensive overlap of this dataset with a PCR-subtraction library enriched for C. graminicola transcripts in planta. Our results demonstrate that LM is feasible for in planta pathogen expression profiling and can reveal clues about fungal genes involved in pathogenesis. The method in this report may be advantageous for visualizing a variety of cellular features that depend on a high degree of histochemical preservation and RNA integrity prior to LM. PMID:17073306

  12. FUM Gene Expression Profile and Fumonisin Production by Fusarium verticillioides Inoculated in Bt and Non-Bt Maize.

    PubMed

    Rocha, Liliana O; Barroso, Vinícius M; Andrade, Ludmila J; Pereira, Gustavo H A; Ferreira-Castro, Fabiane L; Duarte, Aildson P; Michelotto, Marcos D; Correa, Benedito

    2015-01-01

    This study aimed to determine the levels of fumonisins produced by Fusarium verticillioides and FUM gene expression on Bt (Bacillus thuringiensis) and non-Bt maize, post harvest, during different periods of incubation. Transgenic hybrids 30F35 YG, 2B710 Hx and their isogenic (30F35 and 2B710) were collected from the field and a subset of 30 samples selected for the experiments. Maize samples were sterilized by gamma radiation at a dose of 20 kGy. Samples were then inoculated with F. verticillioides and analyzed under controlled conditions of temperature and relative humidity for fumonisin B1 and B2 (FB1 and FB2) production and FUM1, FUM3, FUM6, FUM7, FUM8, FUM13, FUM14, FUM15, and FUM19 expression. 2B710 Hx and 30F35 YG kernel samples were virtually intact when compared to the non-Bt hybrids that came from the field. Statistical analysis showed that FB1 production was significantly lower in 30F35 YG and 2B710 Hx than in the 30F35 and 2B710 hybrids (P < 0.05). However, there was no statistical difference for FB2 production (P > 0.05). The kernel injuries observed in the non-Bt samples have possibly facilitated F. verticillioides penetration and promoted FB1 production under controlled conditions. FUM genes were expressed by F. verticillioides in all of the samples. However, there was indication of lower expression of a few FUM genes in the Bt hybrids; and a weak association between FB1 production and the relative expression of some of the FUM genes were observed in the 30F35 YG hybrid. PMID:26779158

  13. Interlaboratory transfer of a PCR multiplex method for simultaneous detection of four genetically modified maize lines: Bt11, MON810, T25, and GA21.

    PubMed

    Hernández, Marta; Rodríguez-Lázaro, David; Zhang, David; Esteve, Teresa; Pla, Maria; Prat, Salomé

    2005-05-01

    The number of cultured hectares and commercialized genetically modified organisms (GMOs) has increased exponentially in the past 9 years. Governments in many countries have established a policy of labeling all food and feed containing or produced by GMOs. Consequently, versatile, laboratory-transferable GMO detection methods are in increasing demand. Here, we describe a qualitative PCR-based multiplex method for simultaneous detection and identification of four genetically modified maize lines: Bt11, MON810, T25, and GA21. The described system is based on the use of five primers directed to specific sequences in these insertion events. Primers were used in a single optimized multiplex PCR reaction, and sequences of the amplified fragments are reported. The assay allows amplification of the MON810 event from the 35S promoter to the hsp intron yielding a 468 bp amplicon. Amplification of the Bt11 and T25 events from the 35S promoter to the PAT gene yielded two different amplicons of 280 and 177 bp, respectively, whereas amplification of the 5' flanking region of the GA21 gave rise to an amplicon of 72 bp. These fragments are clearly distinguishable in agarose gels and have been reproduced successfully in a different laboratory. Hence, the proposed method comprises a rapid, simple, reliable, and sensitive (down to 0.05%) PCR-based assay, suitable for detection of these four GM maize lines in a single reaction. PMID:15853368

  14. Aspergillus flavus and Fusariumverticillioides Induce Tissue Specific Gene Expression of PRms and UGT in Maize Seed before Fungal Colonization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aspergillus flavus and Fusariumverticillioides are fungal pathogens that colonize maize seeds and contaminate them with mycotoxins. To investigate the plant microbe interactions, we conducted histological and molecular studies to characterize the internal colonization of maize seed by the two fungal...

  15. Gene expression profiling for food safety assessment: examples in potato and maize.

    PubMed

    Dijk, Jeroen P van; Leifert, Carlo; Barros, Eugenia; Kok, Esther J

    2010-12-01

    Since the mid 1990s, microarray analysis has become one of the few tools that can analyze the entire contents of a cell regarding a specific information type. Especially since the development of whole genome microarrays the technique can be considered truly holistic. Most DNA based microarrays are used for the analysis of the total of messenger RNAs (transcriptome) and provide a snap-shot of what's going on in a cell population at the time of sampling. Within the last few years also full genome plant microarrays have become available for several crop species. With these it has been shown that several growing conditions can be separated based on their transcriptome pattern, such as location, year of harvest and agricultural input system, but also different cultivars of the same crop species, including genetically modified ones. A database comprising expression levels of the transcriptome in many different circumstances with a history of safe use would be a good comparator for evaluation of new agricultural practices or cultivars, genetically modified or otherwise obtained. New techniques as next generation sequencing may overcome issues on throughput time and cost, standard operation procedures and array design for individual crops. PMID:20600454

  16. Reduced fitness of Daphnia magna fed a Bt-transgenic maize variety.

    PubMed

    Bøhn, Thomas; Primicerio, Raul; Hessen, Dag O; Traavik, Terje

    2008-11-01

    Genetically modified (GM) maize expressing the Bt-toxin Cry1Ab (Bt-maize) was tested for effects on survival, growth, and reproduction of the water flea Daphnia magna, a crustacean arthropod commonly used as a model organism in ecotoxicological studies. In three repeated experiments, D. magna were fed 100% ground maize in suspension, using either GM or isogenic unmodified (UM) maize. D. magna fed GM-maize showed a significantly reduced fitness performance: The mortality was higher, a lower proportion of females reached sexual maturation, and the overall egg production was lower compared to D. magna fed UM isogenic maize. We conclude that the tested variety of Bt-maize and its UM counterpart do not have the same quality as food sources for this widely used model organism. The combination of a reduced fitness performance combined with earlier onset of reproduction of D. magna fed Bt-maize indicates a toxic effect rather than a lower nutritional value of the GM-maize. PMID:18347840

  17. Dynamic Expression of Imprinted Genes Associates with Maternally Controlled Nutrient Allocation during Maize Endosperm Development[W][OPEN

    PubMed Central

    Xin, Mingming; Yang, Ruolin; Li, Guosheng; Chen, Hao; Laurie, John; Ma, Chuang; Wang, Dongfang; Yao, Yingyin; Larkins, Brian A.; Sun, Qixin; Yadegari, Ramin; Wang, Xiangfeng; Ni, Zhongfu

    2013-01-01

    In angiosperms, the endosperm provides nutrients for embryogenesis and seed germination and is the primary tissue where gene imprinting occurs. To identify the imprintome of early developing maize (Zea mays) endosperm, we performed high-throughput transcriptome sequencing of whole kernels at 0, 3, and 5 d after pollination (DAP) and endosperms at 7, 10, and 15 DAP, using B73 by Mo17 reciprocal crosses. We observed gradually increased expression of paternal transcripts in 3- and 5-DAP kernels. In 7-DAP endosperm, the majority of the genes tested reached a 2:1 maternal versus paternal ratio, suggesting that paternal genes are nearly fully activated by 7 DAP. A total of 116, 234, and 63 genes exhibiting parent-specific expression were identified at 7, 10, and 15 DAP, respectively. The largest proportion of paternally expressed genes was at 7 DAP, mainly due to the significantly deviated parental allele expression ratio of these genes at this stage, while nearly 80% of the maternally expressed genes (MEGs) were specific to 10 DAP and were primarily attributed to sharply increased expression levels compared with the other stages. Gene ontology enrichment analysis of the imprinted genes suggested that 10-DAP endosperm-specific MEGs are involved in nutrient uptake and allocation and the auxin signaling pathway, coincident with the onset of starch and storage protein accumulation. PMID:24058158

  18. Development of Simple Sequence Repeat Markers from Expressed Sequence Tags of the Maize Gray Leaf Spot Pathogen, Cercospora Zea-Maydis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ten simple sequence repeat markers were developed from expressed sequence tags of Cercospora zeae-maydis, the cause of gray leaf spot of maize (Zea mays). All loci were evaluated on 80 isolates from a local population of C. zeae-maydis and all were highly polymorphic, with 4 to 14 alleles per locus....

  19. Baculovirus expression of the maize mitochondrial protein URF13 confers insecticidal activity in cell cultures and larvae.

    PubMed Central

    Korth, K L; Levings, C S

    1993-01-01

    The URF13 protein, which is encoded by the mitochondrial gene T-urf13, is responsible for cytoplasmic male sterility and pathotoxin sensitivity in the Texas male-sterile cytoplasm (cms-T) of maize. Mitochondrial sensitivity to two host-specific fungal toxins (T toxins) is mediated by the interaction of URF13 and T toxins to form pores in the inner mitochondrial membrane. A carbamate insecticide, methomyl, mimics the effects of T toxins on isolated cms-T mitochondria. URF13 was expressed in Spodoptera frugiperda (fall army-worm) cells (Sf9) in culture and in Trichoplusia ni (cabbage looper) larvae with a baculovirus vector. In insect cells, URF13 forms oligomeric structures in the membrane and confers T toxin or methomyl sensitivity. Adding T toxin or methomyl to Sf9 cells producing URF13 causes permeabilization of plasma membranes. In addition, URF13 is toxic to insect cells grown in culture without T toxins or methomyl; even a T-toxin-insensitive mutant form of URF13 is lethal to cell cultures. Baculoviruses expressing URF13 are lethal to T. ni larvae, at times postinjection comparable to those obtained by injecting a baculovirus expressing an insect neurotoxin. This result suggests that URF13 could be useful as a biological control agent for insect pests. Our data indicate that URF13 has two independent mechanisms for toxicity, one that is mediated by T toxin and methomyl and one that is independent of these toxins. Similarly, male sterility and toxin sensitivity in cms-T maize may be due to independent mechanisms. Images Fig. 1 Fig. 2 Fig. 5 Fig. 6 PMID:8475086

  20. Data presenting a modified bacterial expression vector for expressing and purifying Nus solubility-tagged proteins.

    PubMed

    Gupta, Nidhi; Wu, Heng; Terman, Jonathan R

    2016-09-01

    Bacteria are the predominant source for producing recombinant proteins but while many exogenous proteins are expressed, only a fraction of those are soluble. We have found that a new actin regulatory enzyme Mical is poorly soluble when expressed in bacteria but the use of a Nus fusion protein tag greatly increases its solubility. However, available vectors containing a Nus tag have been engineered in a way that hinders the separation of target proteins from the Nus tag during protein purification. We have now used recombinant DNA approaches to overcome these issues and reengineer a Nus solubility tag-containing bacterial expression vector. The data herein present a modified bacterial expression vector useful for expressing proteins fused to the Nus solubility tag and separating such target proteins from the Nus tag during protein purification. PMID:27547802

  1. Genes and Small RNA Transcripts Exhibit Dosage-Dependent Expression Pattern in Maize Copy-Number Alterations.

    PubMed

    Zuo, Tao; Zhang, Jianbo; Lithio, Andrew; Dash, Sudhansu; Weber, David F; Wise, Roger; Nettleton, Dan; Peterson, Thomas

    2016-07-01

    Copy-number alterations are widespread in animal and plant genomes, but their immediate impact on gene expression is still unclear. In animals, copy-number alterations usually exhibit dosage effects, except for sex chromosomes which tend to be dosage compensated. In plants, genes within small duplications (<100 kb) often exhibit dosage-dependent expression, whereas large duplications (>50 Mb) are more often dosage compensated. However, little or nothing is known about expression in moderately-sized (1-50 Mb) segmental duplications, and about the response of small RNAs to dosage change. Here, we compared maize (Zea mays) plants with two, three, and four doses of a 14.6-Mb segment of chromosome 1 that contains ∼300 genes. Plants containing the duplicated segment exhibit dosage-dependent effects on ear length and flowering time. Transcriptome analyses using GeneChip and RNA-sequencing methods indicate that most expressed genes and unique small RNAs within the duplicated segments exhibit dosage-dependent transcript levels. We conclude that dosage effect is the predominant regulatory response for both genes and unique small RNA transcripts in the segmental dosage series we tested. To our knowledge this is the first analysis of small RNA expression in plant gene dosage variants. Because segmental duplications comprise a significant proportion of eukaryotic genomes, these findings provide important new insight into the regulation of genes and small RNAs in response to dosage changes. PMID:27129738

  2. Growth kinetics, nutrient uptake, and expression of the Alcaligenes eutrophus poly(beta-hydroxybutyrate) synthesis pathway in transgenic maize cell suspension cultures.

    PubMed

    Hahn, J J; Eschenlauer, A C; Narrol, M H; Somers, D A; Srienc, F

    1997-01-01

    Transgenic suspension cultures of Black Mexican Sweet maize (Zea mays L.) expressing the Alcaligenes eutrophus genes encoding enzymes of the pathway for biosynthesis of the biodegradable polymer poly(beta-hydroxybutyrate) (PHB) were established as a tool for investigating metabolic regulation of the PHB pathway in plant cells. Cultures were grown in a 2 L modified mammalian cell bioreactor and in shake flasks. Biomass doubling times for transgenic bioreactor cultures (3.42 +/- 0.76 days) were significantly higher than those for untransformed cultures (2.01 +/- 0.33 days). Transgenic expression of the bacterial enzymes beta-ketothiolase (0.140 units/mg protein) and acetoacetyl-CoA reductase (0.636 units/mg protein) was detected by enzyme assays and immunoblots. However, over the first 2 years of cultivation, reductase activity decreased to 0.120 units/mg proteins. Furthermore, the PHB synthase gene, although initially present, was not detectable after 1.5 years of cultivation in suspension culture. These facts suggest that transgenic expression of PHB pathway genes in plant cells may not be stable. A hydroxybutyrate derivative was detected via gas chromatography even after 4 years of cultivation. Although the method used to prepare samples for gas chromatography cannot directly distinguish among PHB polymer, hydroxybutyryl-CoA (HB-CoA), and hydroxybutyric acid, solvent washing experiments indicated that most or all of the signal was non-polymeric, presumably H-CoA. The synthesis of HB-CoA appeared to be linked to substrate growth limitation, with HB-CoA accumulation increasing dramatically and cell growth ceasing upon depletion of ammonium. This suggests that the PHB synthesis pathway in plants is subject to regulatory mechanisms similar to those in prokaryotic cells. PMID:9265773

  3. Comparative biosorption of Mn(II) and Pb(II) ions on raw and oxalic acid modified maize husk: kinetic, thermodynamic and isothermal studies

    NASA Astrophysics Data System (ADS)

    Adeogun, Abideen Idowu; Idowu, Mopelola Abidemi; Ofudje, Andrew Edwin; Kareem, Sarafadeen Olateju; Ahmed, Sikiru Akinyeye

    2013-03-01

    Maize husk, an abundant agricultural waste was used to prepare a biosorbent for the biosorption of Mn(II) and Pb(II) ions from aqueous solution in a batch process. Equilibrium and kinetics of biosorption of the metals ions were studied at 25 °C. The adsorbtion data were treated with common kinetic and isotherm models. The equilibrium data fitted well with Langmuir isotherm with maximum capacity of 8.52 and 7.38 mg g-1 for Mn(II) and Pb(II), respectively on raw biomass (UTCS). The capacity of 9.00 and 9.33 mg g-1 was observed for Mn(II) and Pb(II), respectively on acid modified biomass (ATCS). The study also revealed that the sorption process in both cases depend on biomass dosage, temperature, pH and initial metal ion concentration, respectively. The calculated thermodynamic parameters (∆ G o, ∆ H o and ∆ S o) showed that the biosorption of the metal ions onto maize husk is feasible, spontaneous and exothermic in nature.

  4. CCCH-Type Zinc Finger Family in Maize: Genome-Wide Identification, Classification and Expression Profiling under Abscisic Acid and Drought Treatments

    PubMed Central

    Cao, Jiangang; Zhang, Wei; Jiang, Haiyang; Li, Xiaoyu; Ma, Qing; Zhu, Suwen; Cheng, Beijiu

    2012-01-01

    Background CCCH-type zinc finger proteins comprise a large protein family. Increasing evidence suggests that members of this family are RNA-binding proteins with regulatory functions in mRNA processing. Compared with those in animals, functions of CCCH-type zinc finger proteins involved in plant growth and development are poorly understood. Methodology/Principal Findings Here, we performed a genome-wide survey of CCCH-type zinc finger genes in maize (Zea mays L.) by describing the gene structure, phylogenetic relationships and chromosomal location of each family member. Promoter sequences and expression profiles of putative stress-responsive members were also investigated. A total of 68 CCCH genes (ZmC3H1-68) were identified in maize and divided into seven groups by phylogenetic analysis. These 68 genes were found to be unevenly distributed on 10 chromosomes with 15 segmental duplication events, suggesting that segmental duplication played a major role in expansion of the maize CCCH family. The Ka/Ks ratios suggested that the duplicated genes of the CCCH family mainly experienced purifying selection with limited functional divergence after duplication events. Twelve maize CCCH genes grouped with other known stress-responsive genes from Arabidopsis were found to contain putative stress-responsive cis-elements in their promoter regions. Seven of these genes chosen for further quantitative real-time PCR analysis showed differential expression patterns among five representative maize tissues and over time in response to abscisic acid and drought treatments. Conclusions The results presented in this study provide basic information on maize CCCH proteins and form the foundation for future functional studies of these proteins, especially for those members of which may play important roles in response to abiotic stresses. PMID:22792223

  5. The iojap gene in maize

    SciTech Connect

    Martienssen, Robert

    2001-12-01

    The classical maize mutant iojap (Iodent japonica) has variegated green and white leaves. Green sectors have cells with normal chloroplasts whereas white sectors have cells where plastids fail to differentiate. These mutant plastids, when transmitted through the female gametophyte, do not recover in the presence of wild type Iojap. We cloned the Ij locus, and we have investigated the mechanism of epigenetic inheritance and phenotypic expression. More recently, a modifier of this type of variegation, ''Inhibitor of striate'', has also been cloned. Both the iojap and inhibitor of striate proteins have homologs in bacteria and are members of ancient conserved families found in multiple species. These tools can be used to address fundamental questions of inheritance and variegation associated with this classical conundrum of maize genetics. Since the work of Rhoades there has been considerable speculation concerning the nature of the Iojap gene product, the origin of leaf variegation and the mechanism behind the material inheritance of defective plastids. This has made Iojap a textbook paradigm for cytoplasmic inheritance and nuclear-organellar interaction for almost 50 years. Cloning of the Iojap gene in maize, and homologs in other plants and bacteria, provides a new means to address the origin of heteroplastidity, variegation and cytoplasmic inheritance in higher plants.

  6. Nitrogen-Deficiency Stress Induces Protein Expression Differentially in Low-N Tolerant and Low-N Sensitive Maize Genotypes

    PubMed Central

    Nazir, Muslima; Pandey, Renu; Siddiqi, Tariq O.; Ibrahim, Mohamed M.; Qureshi, Mohammad I.; Abraham, Gerard; Vengavasi, Krishnapriya; Ahmad, Altaf

    2016-01-01

    Nitrogen (N) is essential for proper plant growth and its application has proven to be critical for agricultural produce. However, for unavoidable economic and environmental problems associated with excessive use of N-fertilizers, it is an urgent demand to manage application of fertilizers. Improving the N-use efficiency (NUE) of crop plants to sustain productivity even at low N levels is the possible solution. In the present investigation, contrasting low-N sensitive (HM-4) and low-N tolerant (PEHM-2) genotypes were identified and used for comparative proteome-profiling of leaves under optimum and low N as well as restoration of low N on 3rd (NR3) and 5th (NR5) days after re-supplying N. The analysis of differential expression pattern of proteins was performed by 2-D gel electrophoresis. Significant variations in the expression of proteins were observed under low N, which were genotype specific. In the leaf proteome, 25 spots were influenced by N treatment and four spots were different between the two genotypes. Most of the proteins that were differentially accumulated in response to N level and were involved in photosynthesis and metabolism, affirming the relationship between N and carbon metabolism. In addition to this, greater intensity of some defense proteins in the low N tolerant genotype was found that may have a possible role in imparting it tolerance under N starvation conditions. The new insights generated on maize proteome in response to N-starvation and restoration would be useful toward improvement of NUE in maize. PMID:27047497

  7. Nitrogen-Deficiency Stress Induces Protein Expression Differentially in Low-N Tolerant and Low-N Sensitive Maize Genotypes.

    PubMed

    Nazir, Muslima; Pandey, Renu; Siddiqi, Tariq O; Ibrahim, Mohamed M; Qureshi, Mohammad I; Abraham, Gerard; Vengavasi, Krishnapriya; Ahmad, Altaf

    2016-01-01

    Nitrogen (N) is essential for proper plant growth and its application has proven to be critical for agricultural produce. However, for unavoidable economic and environmental problems associated with excessive use of N-fertilizers, it is an urgent demand to manage application of fertilizers. Improving the N-use efficiency (NUE) of crop plants to sustain productivity even at low N levels is the possible solution. In the present investigation, contrasting low-N sensitive (HM-4) and low-N tolerant (PEHM-2) genotypes were identified and used for comparative proteome-profiling of leaves under optimum and low N as well as restoration of low N on 3rd (NR3) and 5th (NR5) days after re-supplying N. The analysis of differential expression pattern of proteins was performed by 2-D gel electrophoresis. Significant variations in the expression of proteins were observed under low N, which were genotype specific. In the leaf proteome, 25 spots were influenced by N treatment and four spots were different between the two genotypes. Most of the proteins that were differentially accumulated in response to N level and were involved in photosynthesis and metabolism, affirming the relationship between N and carbon metabolism. In addition to this, greater intensity of some defense proteins in the low N tolerant genotype was found that may have a possible role in imparting it tolerance under N starvation conditions. The new insights generated on maize proteome in response to N-starvation and restoration would be useful toward improvement of NUE in maize. PMID:27047497

  8. Physiological quality and gene expression related to heat-resistant proteins at different stages of development of maize seeds.

    PubMed

    Andrade, T; Von Pinho, E V R; Von Pinho, R G; Oliveira, G E; Andrade, V; Fernandes, J S

    2013-01-01

    We quantified and characterized the expression of heat-resistant proteins during seed development of maize lines with distinct levels of tolerance to high drying temperature. A corn field was planted for multiplication of seeds of different lines, two tolerant and two non-tolerant to high drying temperatures. Harvest of the seeds was carried out at various stages of development and they were then subjected to tests of moisture content, germination, first count of germination, accelerated aging, and cold test. The seeds were stored in a freezer for later analysis of expression of heat-resistant proteins by means of real-time PCR, electrophoresis, and spectrophotometry. We observed that heat-resistant proteins are expressed in a differential manner in seeds from different lines and at different stages of development. The expression of heat-resistant proteins was earlier in lines tolerant to high drying temperatures. Greater germination and vigor values was found for seeds collected at the last stage of development. PMID:24085427

  9. Promotion of photosynthesis in transgenic rice over-expressing of maize C4 phosphoenolpyruvate carboxylase gene by nitric oxide donors.

    PubMed

    Chen, Pingbo; Li, Xia; Huo, Kai; Wei, Xiaodong; Dai, Chuanchao; Lv, Chuangen

    2014-03-15

    We determined the effects of exogenous nitric oxide on photosynthesis and gene expression in transgenic rice plants (PC) over-expressing the maize C4pepc gene, which encodes phosphoenolpyruvate carboxylase (PEPC). Seedlings were subjected to treatments with NO donors, an NO scavenger, phospholipase inhibitors, a Ca(2+) chelator, a Ca(2+) channel inhibitor, and a hydrogen peroxide (H2O2) inhibitor, individually and in various combinations. The NO donors significantly increased the net photosynthetic rate (PN) of PC and wild-type (WT), especially that of PC. Treatment with an NO scavenger did inhibit the PN of rice plants. The treatments with phospholipase inhibitors and a Ca(2+) chelator decreased the PN of WT and PC, and photosynthesis was more strongly inhibited in WT than in PC. Further analyses showed that the NO donors increased endogenous levels of NO and PLD activity, but decreased endogenous levels of Ca(2+) both WT and PC. However, there was a greater increase in NO in WT and a greater increase in PLD activity and Ca(2+) level in PC. The NO donors also increased both PEPC activity and pepc gene expression in PC. PEPC activity can be increased by SNP alone. But the expression of its encoding gene in PC might be regulated by SNP, together with PA and Ca(2+). PMID:24594398

  10. High Expression of the Tonoplast Aquaporin ZmTIP1 in Epidermal and Conducting Tissues of Maize1

    PubMed Central

    Barrieu, François; Chaumont, François; Chrispeels, Maarten J.

    1998-01-01

    Aquaporins are integral membrane proteins of the tonoplast and the plasma membrane that facilitate the passage of water through these membranes. Because of their potentially important role in regulating water flow in plants, studies documenting aquaporin gene expression in specialized tissues involved in water and solute transport are important. We used in situ hybridization to examine the expression pattern of the tonoplast aquaporin ZmTIP1 in different organs of maize (Zea mays L.). This tonoplast water channel is highly expressed in the root epidermis, the root endodermis, the small parenchyma cells surrounding mature xylem vessels in the root and the stem, phloem companion cells and a ring of cells around the phloem strand in the stem and the leaf sheath, and the basal endosperm transfer cells in developing kernels. We postulate that the high level of expression of ZmTIP1 in these tissues facilitates rapid flow of water through the tonoplast to permit osmotic equilibration between the cytosol and the vacuolar content, and to permit rapid transcellular water flow through living cells when required. PMID:9701571

  11. Family-wide survey of miR169s and NF-YAs and their expression profiles response to abiotic stress in maize roots.

    PubMed

    Luan, Mingda; Xu, Miaoyun; Lu, Yunming; Zhang, Qiuxue; Zhang, Lan; Zhang, Chunyi; Fan, Yunliu; Lang, Zhihong; Wang, Lei

    2014-01-01

    Previous studies have identified miR169/NF-YA modules are important regulators of plant development and stress responses. Currently, reported genome sequence data offers an opportunity for global characterization of miR169 and NF-YA genes, which may provide insights into the molecular mechanisms of the miR169/NF-YA modules in maize. In our study, fourteen NF-YA transcription factors with conserved domains were identified based on maize genome loci. The miR169 gene family has 18 members that generate 10 mature products, and 8 of these mature miR169 members could target 7 of 14 ZmNF-YA genes in maize. The seven ZmNF-YA proteins were localized to the nucleus while lacked transcriptional activity. We investigated the expression patterns of the zma-miR169 members and their targeted ZmNF-YA genes in maize roots treated by drought stress (polyethylene glycol, PEG), hormone stress (abscisic acid, ABA), and salt stress (NaCl). The zma-miR169 family members were downregulated in short term (0 ∼ 48 h) and generally upregulated over the long term (15 days) in response to the three abiotic stress conditions. Most of the targeted ZmNF-YA genes exhibited a reverse correlation with zma-miR169 gene expression over both the short term and long term. Maize root elongation was promoted by PEG and ABA but repressed by NaCl over the long term. Apparently, ZmNF-YA14 expression perfectly matched the zma-miR169 expression and corresponded to root growth reversely. PMID:24633051

  12. Expression and RNA splicing of the maize glutathione S-transferase Bronze2 gene is regulated by cadmium and other stresses.

    PubMed Central

    Marrs, K A; Walbot, V

    1997-01-01

    The Bronze2 (Bz2) gene in maize (Zea mays) encodes a glutathione S-transferase that performs the last genetically defined step in anthocyanin biosynthesis--tagging anthocyanin precursors with glutathione, allowing for recognition and entry of anthocyanins into the vacuole. Here we show that Bz2 gene expression is highly induced by heavy metals such as cadmium. Treatment of maize seedlings with cadmium results in a 20-fold increase in Bz2 message accumulation and a 50-fold increase in the presence of the unspliced, intron-containing transcript. The increase in message levels during cadmium stress appears to result, at least in part, from activation of an alternative mRNA start site approximately 200 nucleotides upstream of the normal start site; this site is not used in unstressed or heat-stressed tissues. The effect of cadmium on the RNA splicing of Bz2 seems to be specific: splicing of other intron-containing maize genes, including a maize actin gene under the control of the cadmium-inducible Bz2 promoter, is unaffected by cadmium stress. Conversely, Bz2 intron splicing is not affected by other stress conditions that induce Bz2 gene expression, such as abscisic acid, auxin, or cold stress. Surprisingly, the increase in Bz2 mRNA during cadmium stress does not result in an increase in Bz2 glutathione S-transferase activity. We propose that an alternative protein may be encoded by Bz2 that has a role during responses to heavy metals. PMID:9008391

  13. Increased expression of the maize immunoglobulin binding protein homolog b-70 in three zein regulatory mutants.

    PubMed Central

    Boston, R S; Fontes, E B; Shank, B B; Wrobel, R L

    1991-01-01

    Plants carrying floury-2, Defective endosperm-B30, or Mucronate mutations overproduce b-70, a maize homolog of the mammalian immunoglobulin binding protein. During endosperm development in these mutants, levels of both b-70 protein and RNA increase dramatically between 14 days and 20 days after pollination. At later stages, b-70 RNA levels decline while protein levels remain high. The increase in b-70 RNA levels is endosperm specific and dependent on gene dosage in the floury-2 mutant. In all three mutants, the increases in b-70 RNA and protein levels are inversely proportional to changes in zein synthesis. Although b-70 polypeptides can be extracted from purified protein bodies, they carry a carboxy-terminal endoplasmic reticulum retention signal, HDEL. We propose that induction of b-70 in these mutants is a cellular response to abnormally folded or improperly assembled storage proteins and probably reflects its role as a polypeptide chain binding protein. PMID:1840924

  14. Silicon alleviates cadmium toxicity by enhanced photosynthetic rate and modified bundle sheath's cell chloroplasts ultrastructure in maize.

    PubMed

    Vaculík, Marek; Pavlovič, Andrej; Lux, Alexander

    2015-10-01

    Silicon was shown to alleviate the negative effects of various biotic and abiotic stresses on plant growth. Although the positive role of Si on toxic and heavy metal Cd has been already described, the mechanisms have been explained only partially and still remain unclear. In the present study we investigated the effect of Si on photosynthetic-related processes in maize exposed to two different levels of Cd via measurements of net photosynthetic rate (AN), chlorophyll a fluorescence and pigment analysis, as well as studies of leaf tissue anatomy and cell ultrastructure using bright-field and transmission electron microscopy. We found that Si actively alleviated the toxic syndromes of Cd by increasing AN, effective photochemical quantum yield of photosystem II (ϕPSII) and content of assimilation pigments, although did not decrease the concentration of Cd in leaf tissues. Cadmium did not affect the leaf anatomy and ultrastructure of leaf mesophyll's cell chloroplasts; however, Cd negatively affected thylakoid formation in chloroplasts of bundle sheath cells, and this was alleviated by Si. Improved thylakoid formation in bundle sheath's cell chloroplasts may contribute to Si-induced enhancement of photosynthesis and related increase in biomass production in C4 plant maize. PMID:26036417

  15. Expression and cellular localization of rab28 mRNA and Rab28 protein during maize embryogenesis.

    PubMed

    Niogret, M F; Culiáñez-Macià, F A; Goday, A; Mar Albà, M; Pagès, M

    1996-04-01

    The maize abscisic acid (ABA) responsive gene rab28, has been shown to be ABA-inducible in embryos and vegetative tissues. A polyclonal antiserum was raised against Rab28 protein. Using immunoblotting and immunoprecipitation, the antiserum specifically recognized a protein of about 30 kDa and pl 6 which is in close agreement with the molecular weight and pl predicted by the deduced amino acid sequence. The rab28 gene product accumulated during late embryogenesis. In vegetative tissues, dehydration stress induced rab28 gene expression both in the light and in the dark. The spatial and temporal pattern of rab28 mRNA expression during embryogenesis was investigated by in situ hybridization using digoxigenin-labelled rab28 probes, and the immunochemical localization of Rab28 protein using anti-Rab28 antibodies. Expression of rab28 mRNA is restricted to provascular tissues in young embryos, and at later stages of development the most prevalent accumulation occurred in meristem and in the vascular elements of the plumule, root and scutellum. Using immunoelectron microscopy the Rab28 protein has been located in the nucleolus of different cell types. In light of these results the stress regulation of rab28 and a likely role for this protein during late embryogenesis are discussed. PMID:8624517

  16. Identification and expression profiling analysis of calmodulin-binding transcription activator genes in maize (Zea mays L.) under abiotic and biotic stresses

    PubMed Central

    Yue, Runqing; Lu, Caixia; Sun, Tao; Peng, Tingting; Han, Xiaohua; Qi, Jianshuang; Yan, Shufeng; Tie, Shuanggui

    2015-01-01

    The calmodulin-binding transcription activators (CAMTA) play critical roles in plant growth and responses to environmental stimuli. However, how CAMTAs function in responses to abiotic and biotic stresses in maize (Zea mays L.) is largely unknown. In this study, we first identified all the CAMTA homologous genes in the whole genome of maize. The results showed that nine ZmCAMTA genes showed highly diversified gene structures and tissue-specific expression patterns. Many ZmCAMTA genes displayed high expression levels in the roots. We then surveyed the distribution of stress-related cis-regulatory elements in the −1.5 kb promoter regions of ZmCAMTA genes. Notably, a large number of stress-related elements present in the promoter regions of some ZmCAMTA genes, indicating a genetic basis of stress expression regulation of these genes. Quantitative real-time PCR was used to test the expression of ZmCAMTA genes under several abiotic stresses (drought, salt, and cold), various stress-related hormones [abscisic acid, auxin, salicylic acid (SA), and jasmonic acid] and biotic stress [rice black-streaked dwarf virus (RBSDV) infection]. Furthermore, the expression pattern of ZmCAMTA genes under RBSDV infection was analyzed to investigate their potential roles in responses of different maize cultivated varieties to RBSDV. The expression of most ZmCAMTA genes responded to both abiotic and biotic stresses. The data will help us to understand the roles of CAMTA-mediated Ca2+ signaling in maize tolerance to environmental stresses. PMID:26284092

  17. A Modified Sparse Representation Method for Facial Expression Recognition.

    PubMed

    Wang, Wei; Xu, LiHong

    2016-01-01

    In this paper, we carry on research on a facial expression recognition method, which is based on modified sparse representation recognition (MSRR) method. On the first stage, we use Haar-like+LPP to extract feature and reduce dimension. On the second stage, we adopt LC-K-SVD (Label Consistent K-SVD) method to train the dictionary, instead of adopting directly the dictionary from samples, and add block dictionary training into the training process. On the third stage, stOMP (stagewise orthogonal matching pursuit) method is used to speed up the convergence of OMP (orthogonal matching pursuit). Besides, a dynamic regularization factor is added to iteration process to suppress noises and enhance accuracy. We verify the proposed method from the aspect of training samples, dimension, feature extraction and dimension reduction methods and noises in self-built database and Japan's JAFFE and CMU's CK database. Further, we compare this sparse method with classic SVM and RVM and analyze the recognition effect and time efficiency. The result of simulation experiment has shown that the coefficient of MSRR method contains classifying information, which is capable of improving the computing speed and achieving a satisfying recognition result. PMID:26880878

  18. A Modified Sparse Representation Method for Facial Expression Recognition

    PubMed Central

    Wang, Wei; Xu, LiHong

    2016-01-01

    In this paper, we carry on research on a facial expression recognition method, which is based on modified sparse representation recognition (MSRR) method. On the first stage, we use Haar-like+LPP to extract feature and reduce dimension. On the second stage, we adopt LC-K-SVD (Label Consistent K-SVD) method to train the dictionary, instead of adopting directly the dictionary from samples, and add block dictionary training into the training process. On the third stage, stOMP (stagewise orthogonal matching pursuit) method is used to speed up the convergence of OMP (orthogonal matching pursuit). Besides, a dynamic regularization factor is added to iteration process to suppress noises and enhance accuracy. We verify the proposed method from the aspect of training samples, dimension, feature extraction and dimension reduction methods and noises in self-built database and Japan's JAFFE and CMU's CK database. Further, we compare this sparse method with classic SVM and RVM and analyze the recognition effect and time efficiency. The result of simulation experiment has shown that the coefficient of MSRR method contains classifying information, which is capable of improving the computing speed and achieving a satisfying recognition result. PMID:26880878

  19. Maize databases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter is a succinct overview of maize data held in the species-specific database MaizeGDB (the Maize Genomics and Genetics Database), and selected multi-species data repositories, such as Gramene/Ensembl Plants, Phytozome, UniProt and the National Center for Biotechnology Information (NCBI), ...

  20. Genome-Wide Expression of Transcriptomes and Their Co-Expression Pattern in Subtropical Maize (Zea mays L.) under Waterlogging Stress

    PubMed Central

    Thirunavukkarasu, Nepolean; Hossain, Firoz; Mohan, Sweta; Shiriga, Kaliyugam; Mittal, Swati; Sharma, Rinku; Singh, Rita Kumari; Gupta, Hari Shankar

    2013-01-01

    Waterlogging causes extensive damage to maize crops in tropical and subtropical regions. The identification of tolerance genes and their interactions at the molecular level will be helpful to engineer tolerant genotypes. A whole-genome transcriptome assay revealed the specific role of genes in response to waterlogging stress in susceptible and tolerant genotypes. Genes involved in the synthesis of ethylene and auxin, cell wall metabolism, activation of G-proteins and formation of aerenchyma and adventitious roots, were upregulated in the tolerant genotype. Many transcription factors, particularly ERFs, MYB, HSPs, MAPK, and LOB-domain protein were involved in regulation of these traits. Genes responsible for scavenging of ROS generated under stress were expressed along with those involved in carbohydrate metabolism. The physical locations of 21 genes expressed in the tolerant genotype were found to correspond with the marker intervals of known QTLs responsible for development of adaptive traits. Among the candidate genes, most showed synteny with genes of sorghum and foxtail millet. Co-expression analysis of 528 microarray samples including 16 samples from the present study generated seven functional modules each in the two genotypes, with differing characteristics. In the tolerant genotype, stress genes were co-expressed along with peroxidase and fermentation pathway genes. PMID:23936429

  1. Evaluation of the expression genes associated with resistance to Aspergillus flavus colonization and aflatoxin production in different maize lines.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxins are carcinogenic toxic compounds produced by Aspergillus flavus during infection of crops including maize (Zea mays L.). Contamination of maize with aflatoxin is exacerbated by late season drought stress. Previous studies have implicated numerous resistance-associated proteins (RAPs) that...

  2. PR10 expression in maize and its effect on host resistance against Aspergillus flavus infection and aflatoxin production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize (Zea mays L.) is a major crop susceptible to Aspergillus flavus infection and subsequent contamination with aflatoxins, the potent carcinogenic secondary metabolites of the fungus. Protein profiles of maize genotypes resistant and susceptible to A. flavus infection and/or aflatoxin contaminati...

  3. Altered Phenylpropanoid Metabolism in the Maize Lc-Expressed Sweet Potato (Ipomoea batatas) Affects Storage Root Development.

    PubMed

    Wang, Hongxia; Yang, Jun; Zhang, Min; Fan, Weijuan; Firon, Nurit; Pattanaik, Sitakanta; Yuan, Ling; Zhang, Peng

    2016-01-01

    There is no direct evidence of the effect of lignin metabolism on early storage root development in sweet potato. In this study, we found that heterologous expression of the maize leaf color (Lc) gene in sweet potato increased anthocyanin pigment accumulation in the whole plant and resulted in reduced size with an increased length/width ratio, low yield and less starch content in the early storage roots. RT-PCR analysis revealed dramatic up-regulation of the genes involved in the lignin biosynthesis pathway in developing storage roots, leading to greater lignin content in the Lc transgenic lines, compared to the wild type. This was also evidenced by the enhanced lignification of vascular cells in the early storage roots. Furthermore, increased expression of the β-amylase gene in leaves and storage roots also accelerated starch degradation and increased the sugar use efficiency, providing more energy and carbohydrate sources for lignin biosynthesis in the Lc transgenic sweet potato. Lesser starch accumulation was observed in the developing storage roots at the initiation stage in the Lc plants. Our study provides experimental evidence of the basic carbohydrate metabolism underlying the development of storage roots, which is the transformation of lignin biosynthesis to starch biosynthesis. PMID:26727353

  4. Altered Phenylpropanoid Metabolism in the Maize Lc-Expressed Sweet Potato (Ipomoea batatas) Affects Storage Root Development

    PubMed Central

    Wang, Hongxia; Yang, Jun; Zhang, Min; Fan, Weijuan; Firon, Nurit; Pattanaik, Sitakanta; Yuan, Ling; Zhang, Peng

    2016-01-01

    There is no direct evidence of the effect of lignin metabolism on early storage root development in sweet potato. In this study, we found that heterologous expression of the maize leaf color (Lc) gene in sweet potato increased anthocyanin pigment accumulation in the whole plant and resulted in reduced size with an increased length/width ratio, low yield and less starch content in the early storage roots. RT-PCR analysis revealed dramatic up-regulation of the genes involved in the lignin biosynthesis pathway in developing storage roots, leading to greater lignin content in the Lc transgenic lines, compared to the wild type. This was also evidenced by the enhanced lignification of vascular cells in the early storage roots. Furthermore, increased expression of the β-amylase gene in leaves and storage roots also accelerated starch degradation and increased the sugar use efficiency, providing more energy and carbohydrate sources for lignin biosynthesis in the Lc transgenic sweet potato. Lesser starch accumulation was observed in the developing storage roots at the initiation stage in the Lc plants. Our study provides experimental evidence of the basic carbohydrate metabolism underlying the development of storage roots, which is the transformation of lignin biosynthesis to starch biosynthesis. PMID:26727353

  5. Transcriptional photoregulation of cell-type-preferred expression of maize rbcS-m3: 3' and 5' sequences are involved.

    PubMed Central

    Viret, J F; Mabrouk, Y; Bogorad, L

    1994-01-01

    In the C4 plant maize, members of the rbcS gene family, encoding the small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase, are not expressed in mesophyll cells (MC) but are expressed strongly in the adjacent bundle sheath cells (BSC). Expression of genes in an in situ transient expression assay indicates that the photostimulated expression seen in BSC during the first 24 h that leaves of dark-grown seedlings are illuminated requires rbcS-m3 sequences lying between -211 bp and +434 bp of the transcription start site. Photoregulated partial suppression of rbcS-m3 expression in MC, on the other hand, requires gene sequences that lie between -907 bp and -445 bp together with sequences that lie between +720 and +957 bp within the 3' transcribed region of the gene. Suppression in MC occurs during the second 24-h period that dark-grown seedlings have been illuminated, but not during the first 24 h. The 3' +720- to +957-bp region is also effective in lowering MC expression when it is relocated to a position > 2 kbp upstream of the transcription start site. Thus, suppression of rbcS-m3 expression in MC has, at the least, a substantial transcriptional component. As reported earlier, a converse pattern of suppression in BSC and stimulation of expression in MC is seen in the control of cab-m1 in maize leaves. Images PMID:8078926

  6. Answers to critics: Why there is a long term toxicity due to a Roundup-tolerant genetically modified maize and to a Roundup herbicide.

    PubMed

    Séralini, Gilles-Eric; Mesnage, Robin; Defarge, Nicolas; Gress, Steeve; Hennequin, Didier; Clair, Emilie; Malatesta, Manuela; de Vendômois, Joël Spiroux

    2013-03-01

    Our recent work (Séralini et al., 2012) remains to date the most detailed study involving the life-long consumption of an agricultural genetically modified organism (GMO). This is true especially for NK603 maize for which only a 90-day test for commercial release was previously conducted using the same rat strain (Hammond et al., 2004). It is also the first long term detailed research on mammals exposed to a highly diluted pesticide in its total formulation with adjuvants. This may explain why 75% of our first criticisms arising within a week, among publishing authors, come from plant biologists, some developing patents on GMOs, even if it was a toxicological paper on mammals, and from Monsanto Company who owns both the NK603 GM maize and Roundup herbicide (R). Our study has limits like any one, and here we carefully answer to all criticisms from agencies, consultants and scientists, that were sent to the Editor or to ourselves. At this level, a full debate is biased if the toxicity tests on mammals of NK603 and R obtained by Monsanto Company remain confidential and thus unavailable in an electronic format for the whole scientific community to conduct independent scrutiny of the raw data. In our article, the conclusions of long-term NK603 and Roundup toxicities came from the statistically highly discriminant findings at the biochemical level in treated groups in comparison to controls, because these findings do correspond in an blinded analysis to the pathologies observed in organs, that were in turn linked to the deaths by anatomopathologists. GM NK603 and R cannot be regarded as safe to date. PMID:23146697

  7. Molecular composition of leaves and stems of genetically modified Bt and near-isogenic non-Bt maize--characterization of lignin patterns.

    PubMed

    Poerschmann, Juergen; Gathmann, Achim; Augustin, Juergen; Langer, Uwe; Górecki, Tadeusz

    2005-01-01

    Transformation of crops, including maize (Zea mays L.), with the cry1Ab gene from Bacillus thuringiensis to combat lepidopteran pests results in pleiotropic effects regarding lignin biosynthesis. Lignin patterns in stems and leaves of two genetically modified Bt-maize varieties (Novelis T and Valmont T) were studied along with their non-Bt near-isolines (Nobilis and Prelude, respectively). Molecular-level based thermochemolysis using tetramethylammonium hydroxide (TMAH) in combination with gas chromatography-mass spectrometry (GC-MS) was used to quantitate the total lignin contents and to identify monomeric lignin subunits including p-hydroxyphenyl (P), guaiacyl (G), and syringyl (S) moieties. The results were supplemented and confirmed by cupric oxide oxidation. The stems of the transgenic lines had higher concentrations of total lignin than the respective isogenic lines: Valmont T/Prelude by 18% and Novelis T/Nobilis by 28%. In contrast, differences in the total lignin concentration of leaves between the transgenic and the respective near-isogenic lines were marginal. There were significant modifications in the ratio of p-hydroxyphenyl/guaiacyl/syringyl molecular marker units of stem lignin between transgenic and isogenic lines. The guaiacyl units (in particular the G18 marker) accounted chiefly for the higher total lignin contents in the transgenic lines. The leaf lignin patterns did not show significant differences in molecular markers between isogenic and transgenic lines. TMAH-induced thermochemolysis--conducted in both the on-line and off-line modes--provided detailed information on the molecular composition of lignin, thus proving superior to the established "wet chemistry" methods of lignin determination. PMID:16091603

  8. Structure and expression of the maize (Zea mays L.) SUN-domain protein gene family: evidence for the existence of two divergent classes of SUN proteins in plants

    PubMed Central

    2010-01-01

    Background The nuclear envelope that separates the contents of the nucleus from the cytoplasm provides a surface for chromatin attachment and organization of the cortical nucleoplasm. Proteins associated with it have been well characterized in many eukaryotes but not in plants. SUN (Sad1p/Unc-84) domain proteins reside in the inner nuclear membrane and function with other proteins to form a physical link between the nucleoskeleton and the cytoskeleton. These bridges transfer forces across the nuclear envelope and are increasingly recognized to play roles in nuclear positioning, nuclear migration, cell cycle-dependent breakdown and reformation of the nuclear envelope, telomere-led nuclear reorganization during meiosis, and karyogamy. Results We found and characterized a family of maize SUN-domain proteins, starting with a screen of maize genomic sequence data. We characterized five different maize ZmSUN genes (ZmSUN1-5), which fell into two classes (probably of ancient origin, as they are also found in other monocots, eudicots, and even mosses). The first (ZmSUN1, 2), here designated canonical C-terminal SUN-domain (CCSD), includes structural homologs of the animal and fungal SUN-domain protein genes. The second (ZmSUN3, 4, 5), here designated plant-prevalent mid-SUN 3 transmembrane (PM3), includes a novel but conserved structural variant SUN-domain protein gene class. Mircroarray-based expression analyses revealed an intriguing pollen-preferred expression for ZmSUN5 mRNA but low-level expression (50-200 parts per ten million) in multiple tissues for all the others. Cloning and characterization of a full-length cDNA for a PM3-type maize gene, ZmSUN4, is described. Peptide antibodies to ZmSUN3, 4 were used in western-blot and cell-staining assays to show that they are expressed and show concentrated staining at the nuclear periphery. Conclusions The maize genome encodes and expresses at least five different SUN-domain proteins, of which the PM3 subfamily may

  9. A member of the maize isopentenyl transferase gene family, Zea mays isopentenyl transferase 2 (ZmIPT2), encodes a cytokinin biosynthetic enzyme expressed during kernel development. Cytokinin biosynthesis in maize.

    PubMed

    Brugière, Norbert; Humbert, Sabrina; Rizzo, Nancy; Bohn, Jennifer; Habben, Jeffrey E

    2008-06-01

    Cytokinins (CKs) are plant hormones that regulate a large number of processes associated with plant growth and development such as induction of stomata opening, delayed senescence, suppression of auxin-induced apical dominance, signaling of nitrogen availability, differentiation of plastids and control of sink strength. In maize, CKs are thought to play an important role in establishing seed size and increasing seed set under normal and unfavorable environmental conditions therefore influencing yield. In recent years, the discovery of isopentenyl transferase (IPT) genes in plants has shed light on the CK biosynthesis pathway in plants. In an effort to increase our understanding of the role played by CKs in maize development and sink-strength, we identified several putative IPT genes using a bioinformatics approach. We focused our attention on one gene in particular, ZmIPT2, because of its strong expression in developing kernels. The expression of the gene and its product overlays the change in CK levels in developing kernels suggesting a major role in CK biosynthesis for kernel development. We demonstrate that at 8-10 days after pollination (DAP) the endosperm and especially the basal transfer cell layer (BETL) is a major site of ZmIPT2 expression, and that this expression persists in the BETL and the developing embryo into later kernel development stages. We show that ectopic expression of ZmIPT2 in calli and in planta created phenotypes consistent with CK overproduction. We also show that ZmIPT2 preferentially uses ADP and ATP over AMP as the substrates for dimethylallyl diphosphate (DMAPP) IPT activity. The expression pattern of ZmIPT2 in the BETL, endosperm and embryo during kernel development will be discussed with an emphasis on the suggested role of CKs in determining sink-strength and grain production in crop plants. PMID:18311542

  10. Histone Acetylation is Involved in Gibberellin-Regulated sodCp Gene Expression in Maize Aleurone Layers.

    PubMed

    Hou, Haoli; Wang, Pu; Zhang, Hao; Wen, Huan; Gao, Fei; Ma, Ningjie; Wang, Qing; Li, Lijia

    2015-11-01

    The cereal aleurone layer plays an important role in seed germination, and reactive oxygen species (ROS) in aleurone layers act as crucial signal molecules in this progression. Recent studies have revealed that epigenetic modification is involved in plant development and seed germination. However, little is known about a possible relationship between histone modification and the ROS signaling pathway in cereal aleurone layers during seed germination. Here, we found that the expression of both histone acetyltransferases (HATs) and histone deacetylases (HDACs) was increased gradually during seed germination, accompanied by an increase in global acetylation levels of histones H3 and H4 in maize aleurone layers. The acetylation was found to be promoted by GA(3) and suppressed by ABA. However, when the HDAC inhibitor trichostatin A (TSA) was used, the increased H3K9ac and H4K5ac level correlated with an inhibition of the germination. These results indicated that the overall histone acetylation in the aleurone layers is not required for germination. Similarly these two hormones, GA(3) and ABA, exerted opposed effects on the expression of the ROS-related gene sodCp. Furthermore, chromatin immunoprecipitation experiments showed that the promoter region of the sodCp gene was hyperacetylated during germination, and this acetylation was promoted by GA(3) and inhibited by both ABA and TSA. These results suggested that GA(3)-mediated expression of the sodCp gene in aleurone layers is associated with histone hyperacetylation on the promoter and coding region of this gene, consequently leading to an accumulation of H(2)O(2) which regulated production of α-amylase during seed germination. PMID:26374791

  11. Identification, and Functional and Expression Analyses of the CorA/MRS2/MGT-Type Magnesium Transporter Family in Maize.

    PubMed

    Li, Hongyou; Du, Hanmei; Huang, Kaifeng; Chen, Xin; Liu, Tianyu; Gao, Shibin; Liu, Hailan; Tang, Qilin; Rong, Tingzhao; Zhang, Suzhi

    2016-06-01

    Magnesium (Mg(2+)) is an essential macronutrient for plant growth and development, and the CorA/MRS2/MGT-type Mg(2+) transporters play important roles in maintaining Mg(2+) homeostasis in plants. Although the MRS2/MGT genes have been identified in two model plant species, Arabidopsis and rice, a comprehensive analysis of the MRS2/MGT gene family in other plants is lacking. In this work, 12 putative MRS2/MGT genes (ZmMGT1- ZmMGT12) were identified in maize and all of them were classified into five distinct subfamilies by phylogenetic analysis. A complementation assay in the Salmonella typhimurium MM281 strain showed that five representatives of the 12 members possess Mg(2+) transport abilities. Inhibition of ZmMGT protein activity using the hexaamminecobalt (III) (Co-Hex) inhibitor indicated that the ZmMGT protein mediated both low-affinity and high-affinity Mg(2+) transport in maize. A semi-quantitative reverse transcription-PCR (RT-PCR) analysis revealed that eight genes were constitutively expressed in all of the detected tissues, with one being specifically expressed in roots and three having no detectable expression signals. A quantitative RT-PCR analysis showed that some ZmMGT members displayed differential responses to Mg(2+) deficiency and aluminum (Al) stress. Furthermore, root growth inhibition and Mg(2+) accumulation analyses in two maize inbred lines, which conferred different levels of Al tolerance, revealed that ZmMGT proteins contributed to the Al resistance of the Al tolerance genotype. We hypothesize that ZmMGT family members function as Mg(2+) transporters and may play a role in linking Mg(2+) deficiency and Al stress responses. Our results will be valuable in a further analysis of the important biological functions of ZmMGT members in maize. PMID:27084594

  12. ZmPTR1, a maize peptide transporter expressed in the epithelial cells of the scutellum during germination.

    PubMed

    Tnani, Hedia; López-Ribera, Ignacio; García-Muniz, Nora; Vicient, Carlos M

    2013-06-01

    In plants, peptide transporter/nitrate transporter 1 (PTR/NRT1) family proteins transport a variety of substrates such as nitrate, di- and tripepetides, auxin and carboxylates across membranes. We isolated and characterized ZmPTR1, a maize member of this family. ZmPTR1 protein sequence is highly homologous to the previously characterized di- and tripeptide Arabidopsis transporters AtPTR2, AtPTR4 and AtPTR6. ZmPTR1 gene is expressed in the cells of the scutellar epithelium during germination and, to a less extent, in the radicle and the hypocotyl. Arabidopsis thaliana lines overexpressing ZmPTR1 performed better than control plants when grown on a medium with Ala-Ala dipeptide as the unique N source. Our results suggest that ZmPTR1 plays a role in the transport into the embryo of the small peptides produced during enzymatic hydrolysis of the storage proteins in the endosperm. PMID:23602109

  13. Genome-wide meta-analysis of maize heterosis reveals the potential role of additive gene expression at pericentromeric loci

    PubMed Central

    2014-01-01

    Background The identification of QTL involved in heterosis formation is one approach to unravel the not yet fully understood genetic basis of heterosis - the improved agronomic performance of hybrid F1 plants compared to their inbred parents. The identification of candidate genes underlying a QTL is important both for developing markers and determining the molecular genetic basis of a trait, but remains difficult owing to the large number of genes often contained within individual QTL. To address this problem in heterosis analysis, we applied a meta-analysis strategy for grain yield (GY) of Zea mays L. as example, incorporating QTL-, hybrid field-, and parental gene expression data. Results For the identification of genes underlying known heterotic QTL, we made use of tight associations between gene expression pattern and the trait of interest, identified by correlation analyses. Using this approach genes strongly associated with heterosis for GY were discovered to be clustered in pericentromeric regions of the complex maize genome. This suggests that expression differences of sequences in recombination-suppressed regions are important in the establishment of heterosis for GY in F1 hybrids and also in the conservation of heterosis for GY across genotypes. Importantly functional analysis of heterosis-associated genes from these genomic regions revealed over-representation of a number of functional classes, identifying key processes contributing to heterosis for GY. Based on the finding that the majority of the analyzed heterosis-associated genes were addtitively expressed, we propose a model referring to the influence of cis-regulatory variation on heterosis for GY by the compensation of fixed detrimental expression levels in parents. Conclusions The study highlights the utility of a meta-analysis approach that integrates phenotypic and multi-level molecular data to unravel complex traits in plants. It provides prospects for the identification of genes relevant for

  14. Pyrophosphate-Dependent Fructose-6-Phosphate 1-Phosphotransferase Induction and Attenuation of Hsp Gene Expression during Endosperm Modification in Quality Protein Maize1[C][W][OA

    PubMed Central

    Guo, Xiaomei; Ronhovde, Kyla; Yuan, Lingling; Yao, Bo; Soundararajan, Madhavan P.; Elthon, Thomas; Zhang, Chi; Holding, David R.

    2012-01-01

    Quality Protein Maize (QPM) is a hard-endosperm version of the high-lysine opaque2 (o2) maize (Zea mays) mutant, but the genes involved in modification of the soft o2 endosperm are largely unknown. Pyrophosphate-dependent fructose-6-phosphate 1-phosphotransferase (PFP) catalyzes the ATP-independent conversion of fructose-6-phosphate to fructose-1,6-bisphosphate in glycolysis. We found a large increase in transcript and protein levels of the α-regulatory subunit of PFP (PFPα) in QPM endosperm. In vitro enzyme assays showed a significant increase in forward PFP activity in developing endosperm extracts of QPM relative to the wild type and o2. An expressed retrogene version of PFPα of unknown function that was not up-regulated in QPM was also identified. The elevated expression levels of a number of ATP-requiring heat shock proteins (Hsps) in o2 endosperm are ameliorated in QPM. PFPα is also coinduced with Hsps in maize roots in response to heat, cold, and the unfolded protein response stresses. We propose that reduced ATP availability resulting from the generalized Hsp response in addition to the reduction of pyruvate, orthophosphate dikinase activity in o2 endosperm is compensated in part by increased PFP activity in QPM. PMID:22158678

  15. Resistance to Fusarium verticillioides and fumonisin accumulation in maize inbred lines involves an earlier and enhanced expression of lipoxygenase (LOX) genes.

    PubMed

    Maschietto, Valentina; Marocco, Adriano; Malachova, Alexandra; Lanubile, Alessandra

    2015-09-01

    Fusarium verticillioides causes ear rot in maize and contaminates the kernels with the fumonisin mycotoxins. It is known that plant lipoxygenase (LOX)-derived oxylipins regulate defence against pathogens and that the host-pathogen lipid cross-talk influences the pathogenesis. The expression profiles of fifteen genes of the LOX pathway were studied in kernels of resistant and susceptible maize lines, grown in field condition, at 3, 7 and 14 days post inoculation (dpi) with F. verticillioides. Plant defence responses were correlated with the pathogen growth, the expression profiles of fungal FUM genes for fumonisin biosynthesis and fumonisin content in the kernels. The resistant genotype limited fungal growth and fumonisin accumulation between 7 and 14 dpi. Pathogen growth became exponential in the susceptible line after 7 dpi, in correspondence with massive transcription of FUM genes and fumonisins augmented exponentially at 14 dpi. LOX pathway genes resulted strongly induced after pathogen inoculation in the resistant line at 3 and 7 dpi, whilst in the susceptible line the induction was reduced or delayed at 14 dpi. In addition, all genes resulted overexpressed before infection in kernels of the resistant genotype already at 3 dpi. The results suggest that resistance in maize may depend on an earlier activation of LOX genes and genes for jasmonic acid biosynthesis. PMID:26398628

  16. Aspergillus flavus and fusarium verticillioides induce tissue specific gene expression of PRms and UGT in maize kernels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aspergillus flavus and Fusarium verticillioides are fungal pathogens capable of colonizing maize kernels and contaminating them with mycotoxins. Development of effective control strategies is extremely difficult because pathogenesis and host response remain poorly understood. In this study, we monit...

  17. Developmental patterns of chromatin structure and DNA methylation responsible for epigenetic expression of a maize regulatory gene.

    PubMed Central

    Hoekenga, O A; Muszynski, M G; Cone, K C

    2000-01-01

    Epigenetic regulatory mechanisms heritably alter patterns of gene expression without changes in DNA sequence. Epigenetic states are often correlated with developmentally imposed alterations in genomic DNA methylation and local chromatin structure. Pl-Blotched is a stable epigenetic allele of the maize anthocyanin regulatory gene, purple plant1(pl). Pl-Blotched plants display a variegated pattern of pigmentation that contrasts sharply with the uniformly dark purple pigmentation of plants carrying the dominant Pl-Rhoades allele. Previously, we showed that the lower level of pigmentation in Pl-Blotched is correlated with lower pl mRNA levels and increased DNA methylation at some sites. To explore how DNA methylation, chromatin structure, and developmental stage might contribute to the expression of Pl-Blotched, we used methylation-sensitive restriction enzymes and DNaseI sensitivity assays to compare the methylation status and chromatin structure of Pl-Blotched and Pl-Rhoades at different stages in development. Both alleles exhibit developmentally sensitive changes in methylation. In Pl-Blotched, methylation of two diagnostic HpaII/MspI sites increases progressively, coincident with the juvenile-to-adult transition in growth. In seedlings, the chromatin encompassing the coding region of the gene is less sensitive to DNaseI digestion in Pl-Blotched than in Pl-Rhoades. Developmental maturation from seedling to adult is accompanied by expansion of this closed chromatin domain to include the promoter and downstream flanking sequences. We provide evidence to show that chromatin structure, rather than DNA methylation, is the primary epigenetic determinant for the phenotypic differences between Pl-Blotched and Pl-Rhoades. PMID:10924483

  18. Use of Mutant-Assisted Gene Identification and Characterization (MAGIC) to identify novel genetic loci that modify the maize hypersensitive response

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The partially-dominant, autoactive maize disease resistance gene Rp1-D21 causes hypersensitive response (HR) lesions to form spontaneously on the leaves and stem in the absence of pathogen recognition. The maize nested association mapping (NAM) population consists of 25 200-line subpopulations each...

  19. Development, Optimization, and Evaluation of a Duplex Droplet Digital PCR Assay To Quantify the T-nos/hmg Copy Number Ratio in Genetically Modified Maize.

    PubMed

    Félix-Urquídez, Dalmira; Pérez-Urquiza, Melina; Valdez Torres, José-Benigno; León-Félix, Josefina; García-Estrada, Raymundo; Acatzi-Silva, Abraham

    2016-01-01

    Certified reference materials (CRMs) are required to guarantee the reliability of analytical measurements. The CRMs available in the field of genetically modified organisms (GMOs) are characterized using real-time polymerase chain reaction (qPCR). This technology has limited application, because of its dependence on a calibrant. The objective of this study was to obtain a method with higher metrological quality, to characterize the CRMs for their contents of T-nos/hmg copy number ratio in maize. A duplex droplet digital PCR (ddPCR) assay was developed and optimized by a central composite design. The developed method achieved an absolute limit of detection (LOD) of 11 cP T-nos, a relative LOD of 0.034%, a limit of quantification (LOQ) of 23 cP (relative LOQ of 0.08%), and a dynamic range of 0.08%-100% T-nos/hmg ratio. The specificity and applicability of the assay were established for the analysis of low T-nos concentrations (0.9%) in several corn varieties. The convenience of DNA digestion to reduce measurement bias in the case of multiple-copy binding was confirmed through an enzymatic restriction assay. Given its overall performance, this method can be used to characterize CRM candidates for their contents of T-nos/hmg ratio. PMID:26605751

  20. Expression of zma-miR169 miRNAs and their target ZmNF-YA genes in response to abiotic stress in maize leaves.

    PubMed

    Luan, Mingda; Xu, Miaoyun; Lu, Yunming; Zhang, Lan; Fan, Yunliu; Wang, Lei

    2015-01-25

    The miR169 miRNA family is highly conserved in plants. Its members regulate the expression of genes encoding the universal transcription factor subunit NUCLEAR FACTOR-Y subunit A (NF-YA) via transcript cleavage. NF-YA regulates gene expression by binding the CCAAT box sequence in target promoters. The miR169/NF-YA module plays a critical role during plant development and in plant responses to abiotic stress. We characterized the secondary structures of maize pre-miR169 miRNAs and predicted their potential gene targets. Coexpression of zma-miR169 and ZmNF-YA in Nicotiana benthamiana demonstrated that mutations in or deletion of target sites abolished regulation by zma-miR169. Maize seedlings were subjected to short-term (0-48h) and long-term (15days) drought, abscisic acid (ABA), or salt stress. Long-term exposure to PEG (drought stress) or NaCl (salt stress) repressed seedling growth. We investigated the expression patterns of zma-miR169s and their target ZmNF-YA genes in maize leaves and found diverse changes in expression in response to the three stress treatments. The expression of most zma-miR169 genes was downregulated by PEG and upregulated by ABA. In response to salt stress, zma-miR169 genes were upregulated initially and subsequently downregulated. Most ZmNF-YA genes were upregulated during the short term and downregulated by 15days in response to the three stress treatments. PMID:25445264

  1. MaizeGDB update: new tools, data and interface for the maize model organism database

    PubMed Central

    Andorf, Carson M.; Cannon, Ethalinda K.; Portwood, John L.; Gardiner, Jack M.; Harper, Lisa C.; Schaeffer, Mary L.; Braun, Bremen L.; Campbell, Darwin A.; Vinnakota, Abhinav G.; Sribalusu, Venktanaga V.; Huerta, Miranda; Cho, Kyoung Tak; Wimalanathan, Kokulapalan; Richter, Jacqueline D.; Mauch, Emily D.; Rao, Bhavani S.; Birkett, Scott M.; Sen, Taner Z.; Lawrence-Dill, Carolyn J.

    2016-01-01

    MaizeGDB is a highly curated, community-oriented database and informatics service to researchers focused on the crop plant and model organism Zea mays ssp. mays. Although some form of the maize community database has existed over the last 25 years, there have only been two major releases. In 1991, the original maize genetics database MaizeDB was created. In 2003, the combined contents of MaizeDB and the sequence data from ZmDB were made accessible as a single resource named MaizeGDB. Over the next decade, MaizeGDB became more sequence driven while still maintaining traditional maize genetics datasets. This enabled the project to meet the continued growing and evolving needs of the maize research community, yet the interface and underlying infrastructure remained unchanged. In 2015, the MaizeGDB team completed a multi-year effort to update the MaizeGDB resource by reorganizing existing data, upgrading hardware and infrastructure, creating new tools, incorporating new data types (including diversity data, expression data, gene models, and metabolic pathways), and developing and deploying a modern interface. In addition to coordinating a data resource, the MaizeGDB team coordinates activities and provides technical support to the maize research community. MaizeGDB is accessible online at http://www.maizegdb.org. PMID:26432828

  2. MaizeGDB update: new tools, data and interface for the maize model organism database.

    PubMed

    Andorf, Carson M; Cannon, Ethalinda K; Portwood, John L; Gardiner, Jack M; Harper, Lisa C; Schaeffer, Mary L; Braun, Bremen L; Campbell, Darwin A; Vinnakota, Abhinav G; Sribalusu, Venktanaga V; Huerta, Miranda; Cho, Kyoung Tak; Wimalanathan, Kokulapalan; Richter, Jacqueline D; Mauch, Emily D; Rao, Bhavani S; Birkett, Scott M; Sen, Taner Z; Lawrence-Dill, Carolyn J

    2016-01-01

    MaizeGDB is a highly curated, community-oriented database and informatics service to researchers focused on the crop plant and model organism Zea mays ssp. mays. Although some form of the maize community database has existed over the last 25 years, there have only been two major releases. In 1991, the original maize genetics database MaizeDB was created. In 2003, the combined contents of MaizeDB and the sequence data from ZmDB were made accessible as a single resource named MaizeGDB. Over the next decade, MaizeGDB became more sequence driven while still maintaining traditional maize genetics datasets. This enabled the project to meet the continued growing and evolving needs of the maize research community, yet the interface and underlying infrastructure remained unchanged. In 2015, the MaizeGDB team completed a multi-year effort to update the MaizeGDB resource by reorganizing existing data, upgrading hardware and infrastructure, creating new tools, incorporating new data types (including diversity data, expression data, gene models, and metabolic pathways), and developing and deploying a modern interface. In addition to coordinating a data resource, the MaizeGDB team coordinates activities and provides technical support to the maize research community. MaizeGDB is accessible online at http://www.maizegdb.org. PMID:26432828

  3. Changes in endogenous gene transcript and protein levels in maize plants expressing the soybean ferritin transgene

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transgenic agricultural crops with increased nutritive value present prospects for contributing to public health. However, their acceptance is poor in many countries due to the perception that genetic modification may cause unintended effects on expression of native genes in the host plant. Here, w...

  4. Effect of post-silking drought on nitrogen partitioning and gene expression patterns of glutamine synthetase and asparagine synthetase in two maize (Zea mays L.) varieties.

    PubMed

    Li, Yajun; Wang, Meiling; Zhang, Fengxia; Xu, Yadong; Chen, Xiaohong; Qin, Xiaoliang; Wen, Xiaoxia

    2016-05-01

    Glutamine synthetase (GS) and asparagine synthetase (AS) are proposed to have important function in plant nitrogen (N) remobilization, but their roles under drought stress are not well defined. In this study, the expression dynamics of GS and AS genes were analyzed in two maize varieties (ZD958 and NH101) in relation to post-silking drought stress induced nitrogen partitioning. ZD958 was a 'stay-green' variety with 5% nitrogen harvest index (NHI) lower than NH101. From silking to maturity, the amount of nitrogen remobilized from ear-leaves in ZD958 was evidently lower than NH101, and post-silking drought stress increased the nitrogen remobilization for both varieties. In ear-leaves, the expression of ZmGln1-3 was enhanced under drought stress. Three AS genes (ZmAS1, ZmAS2 and ZmAS3) were differentially regulated by post-silking drought treatment, of which the expression of ZmAS3 was stimulated at late stage of leaf senescence. In NH101, the expression level of ZmAS3 was markedly higher than that in ZD958. In developing grains, there were no significant differences in expression patterns of GS and AS genes between well water and drought treated plants. Drought stress altered maize N partitioning at the whole-plant level, and the up-regulation of GS and AS genes may contribute to the higher leaf nitrogen remobilization when exposed to drought treatments. PMID:26913793

  5. Expresiones locativas modificadoras de sustantivo (Locative Expressions Modifying Nouns).

    ERIC Educational Resources Information Center

    Wonder, John P.

    1979-01-01

    Elaborates on and updates the article "Derived Noun Phrases in Spanish Containing Locatives" by John P. Wonder and Alberto Eraso Guerrero (1976). Gives a detailed description of the uses of "ser" and "haber" in the locative expression. (NCR)

  6. Characterization of the inaA gene and expression of ice nucleation phenotype in Pantoea ananatis isolates from Maize White Spot disease.

    PubMed

    Miller, A M; Figueiredo, J E F; Linde, G A; Colauto, N B; Paccola-Meirelles, L D

    2016-01-01

    Maize White Spot (MWS), a foliar disease caused by Pantoea ananatis, could cause up to 60% yield loss. Some strains of P. ananatis harboring the ice nucleation gene inaA catalyze the formation of ice nuclei, causing tissue damage at temperatures slightly below freezing. Little is known about the relationship between the presence of the ina gene in this maize pathogen and its expression during the phenomenon of ice nucleus formation. Here, we attempted to verify the presence of the inaA gene and the expression of phenotype in vitro. The identity of the isolates and the presence of the inaA gene were determined by P. ananatis species-specific primers. The expression of the inaA gene was assessed in vitro by the visualization of ice-crystal formation in water at subzero temperatures. A total of ninety P. ananatis isolates from MWS lesions were characterized. The presence of the inaA gene was confirmed by gel electrophoresis of the 350-400-bp PCR products. The inaA primers did not lead to DNA fragment amplification in three isolates. The ice nucleation phenotype was expressed in 83.34% of the isolates carrying the inaA gene. Our study showed that the ice nucleation in P. ananatis isolated from MWS lesions was dependent on the presence of a functional ina gene in the genome. We also found evidence indicating that some P. ananatis strains have a mutated form of the inaA gene, producing a non-functional ice nucleation protein. This is the first report on inaA gene characterization in P. ananatis isolates from Maize White Spot. PMID:26985943

  7. Stable Carbon Isotope Discrimination Is under Genetic Control in the C4 Species Maize with Several Genomic Regions Influencing Trait Expression1[W

    PubMed Central

    Gresset, Sebastian; Westermeier, Peter; Rademacher, Svenja; Ouzunova, Milena; Presterl, Thomas; Westhoff, Peter; Schön, Chris-Carolin

    2014-01-01

    In plants with C4 photosynthesis, physiological mechanisms underlying variation in stable carbon isotope discrimination (Δ13C) are largely unknown, and genetic components influencing Δ13C have not been described. We analyzed a maize (Zea mays) introgression library derived from two elite parents to investigate whether Δ13C is under genetic control in this C4 species. High-density genotyping with the Illumina MaizeSNP50 Bead Chip was used for a detailed structural characterization of 89 introgression lines. Phenotypic analyses were conducted in the field and in the greenhouse for kernel Δ13C as well as plant developmental and photosynthesis-related traits. Highly heritable significant genetic variation for Δ13C was detected under field and greenhouse conditions. For several introgression library lines, Δ13C values consistently differed from the recurrent parent within and across the two phenotyping platforms. Δ13C was significantly associated with 22 out of 164 analyzed genomic regions, indicating a complex genetic architecture of Δ13C. The five genomic regions with the largest effects were located on chromosomes 1, 2, 6, 7, and 9 and explained 55% of the phenotypic variation for Δ13C. Plant development stage had no effect on Δ13C expression, as phenotypic as well as genotypic correlations between Δ13C, flowering time, and plant height were not significant. To our knowledge, this is the first study demonstrating Δ13C to be under polygenic control in the C4 species maize. PMID:24280436

  8. Transgenic tobacco expressing a modified spider peptide inhibits the growth of plant pathogens and insect larvae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The gene encoding lycotoxin I, an amphipathic pore-forming peptide, was modified to increase oral toxicity to insects. One of the most active modified genes was then constitutively expressed in tobacco (Nicotiana tabacum) and transformants were evaluated for insect and disease resistance. Pathogenic...

  9. A Dominant Negative Mutant of Cyclin-Dependent Kinase A Reduces Endoreduplication but Not Cell Size or Gene Expression in Maize Endosperm

    PubMed Central

    Leiva-Neto, João T.; Grafi, Gideon; Sabelli, Paolo A.; Dante, Ricardo A.; Woo, Young-min; Maddock, Sheila; Gordon-Kamm, William J.; Larkins, Brian A.

    2004-01-01

    Cells in maize (Zea mays) endosperm undergo multiple cycles of endoreduplication, with some attaining DNA contents as high as 96C and 192C. Genome amplification begins around 10 d after pollination, coincident with cell enlargement and the onset of starch and storage protein accumulation. Although the role of endoreduplication is unclear, it is thought to provide a mechanism that increases cell size and enhances gene expression. To investigate this process, we reduced endoreduplication in transgenic maize endosperm by ectopically expressing a gene encoding a dominant negative mutant form of cyclin-dependent kinase A. This gene was regulated by the 27-kD γ-zein promoter, which restricted synthesis of the defective enzyme to the endoreduplication rather than the mitotic phase of endosperm development. Overexpression of a wild-type cyclin-dependent kinase A increased enzyme activity but had no effect on endoreduplication. By contrast, ectopic expression of the defective enzyme lowered kinase activity and reduced by half the mean C-value and total DNA content of endosperm nuclei. The lower level of endoreduplication did not affect cell size and only slightly reduced starch and storage protein accumulation. There was little difference in the level of endosperm gene expression with high and low levels of endoreduplication, suggesting that this process may not enhance transcription of genes associated with starch and storage protein synthesis. PMID:15208390

  10. Characterization of New Maize Genes Putatively Involved in Cytokinin Metabolism and Their Expression during Osmotic Stress in Relation to Cytokinin Levels1[W

    PubMed Central

    Vyroubalová, Šárka; Václavíková, Kateřina; Turečková, Veronika; Novák, Ondřej; Šmehilová, Mária; Hluska, Tomáš; Ohnoutková, Ludmila; Frébort, Ivo; Galuszka, Petr

    2009-01-01

    Plant hormones, cytokinins (CKs), have been for a long time considered to be involved in plant responses to stress. However, their exact roles in processes linked to stress signalization and acclimatization to adverse environmental conditions are unknown. In this study, expression profiles of the entire gene families of CK biosynthetic and degradation genes in maize (Zea mays) during development and stress responses are described. Transcript abundance of particular genes is discussed in relation to the levels of different CK metabolites. Salt and osmotic stresses induce expression of some CK biosynthetic genes in seedlings of maize, leading to a moderate increase of active forms of CKs lasting several days during acclimatization to stress. A direct effect of CKs to mediate activation of stress responses does not seem to be possible due to the slow changes in metabolite levels. However, expression of genes involved in cytokinin signal transduction is uniformly down-regulated within 0.5 h of stress induction by an unknown mechanism. cis-Zeatin and its derivatives were found to be the most abundant CKs in young maize seedlings. We demonstrate that levels of this zeatin isomer are significantly enhanced during early stress response and that it originates independently from de novo biosynthesis in stressed tissues, possibly by elevated specific RNA degradation. By enhancing their CK levels, plants could perhaps undergo a reduction of growth rates maintained by abscisic acid accumulation in stressed tissues. A second role for cytokinin receptors in sensing turgor response is hypothesized besides their documented function in CK signaling. PMID:19641027

  11. Homogalacturonan-modifying enzymes: structure, expression, and roles in plants

    PubMed Central

    Sénéchal, Fabien; Wattier, Christopher; Rustérucci, Christine; Pelloux, Jérôme

    2014-01-01

    Understanding the changes affecting the plant cell wall is a key element in addressing its functional role in plant growth and in the response to stress. Pectins, which are the main constituents of the primary cell wall in dicot species, play a central role in the control of cellular adhesion and thereby of the rheological properties of the wall. This is likely to be a major determinant of plant growth. How the discrete changes in pectin structure are mediated is thus a key issue in our understanding of plant development and plant responses to changes in the environment. In particular, understanding the remodelling of homogalacturonan (HG), the most abundant pectic polymer, by specific enzymes is a current challenge in addressing its fundamental role. HG, a polymer that can be methylesterified or acetylated, can be modified by HGMEs (HG-modifying enzymes) which all belong to large multigenic families in all species sequenced to date. In particular, both the degrees of substitution (methylesterification and/or acetylation) and polymerization can be controlled by specific enzymes such as pectin methylesterases (PMEs), pectin acetylesterases (PAEs), polygalacturonases (PGs), or pectate lyases-like (PLLs). Major advances in the biochemical and functional characterization of these enzymes have been made over the last 10 years. This review aims to provide a comprehensive, up to date summary of the recent data concerning the structure, regulation, and function of these fascinating enzymes in plant development and in response to biotic stresses. PMID:25056773

  12. Nurr1 expression is modified by inflammation in microglia.

    PubMed

    Lallier, Scott W; Graf, Amanda E; Waidyarante, Gavisha R; Rogers, Lynette K

    2016-10-19

    Advances in neonatal care have allowed premature infants to survive at earlier gestational ages, but they are often afflicted with neurological delays or deficits. Maternal inflammation has been identified as a major risk factor for premature birth and once born, infants often require supplemental oxygen for survival. Nurr1 (NR4A2) is an orphan nuclear receptor with no known binding site and is essential for the growth of midbrain dopamine neurons. Others have reported that Nurr1 can act as an anti-inflammatory transcription factor in microglia and astrocytes and respond lipopolysaccharide (LPS). We have previously reported decreased numbers of oligodendrocytes and increased numbers of microglia in the mice exposed to both maternal inflammation and neonatal hyperoxia in the perinatal period. These studies tested the hypothesis that the combined exposures to inflammation and hyperoxia would increase Nurr1 expression in microglia in our mouse model and in an immortalized microglia cell line, BV2 cells. Our data indicate that Nurr1 protein expression is increased at postnatal day 0 and postnatal day 28 in whole-brain homogenates from mice exposed to LPS and hyperoxia. Alternatively, Nurr1 message is decreased at postnatal day 60 in isolated microglia, indicating that the increases in whole-brain homogenates may be due to other cell types. In BV2 cells, Nurr1 message in increased by exposure to hyperoxia, but this increase is attenuated in cells exposed to both LPS and hyperoxia. Although Nurr1 regulation is not straightforward, these data indicate that Nurr1 expression is increased in whole-brain homogenates in response to inflammation, but is decreased in isolated primary microglia and BV2 cells in response to similar inflammation. Our data support the hypothesis that Nurr1 expression may play a significant role in regulating inflammation in the brain and understanding the complex regulation of Nurr1 could lead to new therapeutic strategies. PMID:27532877

  13. A modified consumer inkjet for spatiotemporal control of gene expression.

    PubMed

    Cohen, Daniel J; Morfino, Roberto C; Maharbiz, Michel M

    2009-01-01

    This paper presents a low-cost inkjet dosing system capable of continuous, two-dimensional spatiotemporal regulation of gene expression via delivery of diffusible regulators to a custom-mounted gel culture of E. coli. A consumer-grade, inkjet printer was adapted for chemical printing; E. coli cultures were grown on 750 microm thick agar embedded in micro-wells machined into commercial compact discs. Spatio-temporal regulation of the lac operon was demonstrated via the printing of patterns of lactose and glucose directly into the cultures; X-Gal blue patterns were used for visual feedback. We demonstrate how the bistable nature of the lac operon's feedback, when perturbed by patterning lactose (inducer) and glucose (inhibitor), can lead to coordination of cell expression patterns across a field in ways that mimic motifs seen in developmental biology. Examples of this include sharp boundaries and the generation of traveling waves of mRNA expression. To our knowledge, this is the first demonstration of reaction-diffusion effects in the well-studied lac operon. A finite element reaction-diffusion model of the lac operon is also presented which predicts pattern formation with good fidelity. PMID:19763256

  14. A Modified Consumer Inkjet for Spatiotemporal Control of Gene Expression

    PubMed Central

    Cohen, Daniel J.; Morfino, Roberto C.; Maharbiz, Michel M.

    2009-01-01

    This paper presents a low-cost inkjet dosing system capable of continuous, two-dimensional spatiotemporal regulation of gene expression via delivery of diffusible regulators to a custom-mounted gel culture of E. coli. A consumer-grade, inkjet printer was adapted for chemical printing; E. coli cultures were grown on 750 µm thick agar embedded in micro-wells machined into commercial compact discs. Spatio-temporal regulation of the lac operon was demonstrated via the printing of patterns of lactose and glucose directly into the cultures; X-Gal blue patterns were used for visual feedback. We demonstrate how the bistable nature of the lac operon's feedback, when perturbed by patterning lactose (inducer) and glucose (inhibitor), can lead to coordination of cell expression patterns across a field in ways that mimic motifs seen in developmental biology. Examples of this include sharp boundaries and the generation of traveling waves of mRNA expression. To our knowledge, this is the first demonstration of reaction-diffusion effects in the well-studied lac operon. A finite element reaction-diffusion model of the lac operon is also presented which predicts pattern formation with good fidelity. PMID:19763256

  15. Water deficit stress tolerance in maize conferred by expression of an isopentenyltransferase (IPT) gene driven by a stress- and maturation-induced promoter.

    PubMed

    Décima Oneto, Cecilia; Otegui, María Elena; Baroli, Irene; Beznec, Ailin; Faccio, Paula; Bossio, Ezequiel; Blumwald, Eduardo; Lewi, Dalia

    2016-02-20

    Senescence can be delayed in transgenic plants overexpressing the enzyme isopentenyltransferase (IPT) due to stress-induced increased levels of endogenous cytokinins. This trait leads to sustained photosynthetic activity and improved tolerance to abiotic stress. The aim of this study was to generate and characterize transgenic plants of maize (Zea mays L.) transformed with the IPT gene sequence under the regulation of SARK promoter (protein kinase receptor-associated senescence). Three independent transgenic events and their segregating null controls were evaluated in two watering regimes (WW: well watered; WD: water deficit) imposed for two weeks around anthesis. Our results show that the WD treatment induced IPT expression with the concomitant increase in cytokinin levels, which prolonged the persistence of total green leaf area, and maintained normal photosynthetic rate and stomatal conductance. These trends were accompanied by a minor decrease in number of grains per plant, individual grain weight and plant grain yield as compared to WW plants. Plants expressing the IPT gene under WD had PGR, anthesis and silking dates and biomass levels similar to WW plants. Our results demonstrate that expression of the IPT gene under the regulation of the SARK promoter helps improve productivity under WD conditions in C4 plants like maize. PMID:26784988

  16. An efficient virus-induced gene silencing vector for maize functional genomics research.

    PubMed

    Wang, Rong; Yang, Xinxin; Wang, Nian; Liu, Xuedong; Nelson, Richard S; Li, Weimin; Fan, Zaifeng; Zhou, Tao

    2016-04-01

    Maize is a major crop whose rich genetic diversity provides an advanced resource for genetic research. However, a tool for rapid transient gene function analysis in maize that may be utilized in most maize cultivars has been lacking, resulting in reliance on time-consuming stable transformation and mutation studies to obtain answers. We developed an efficient virus-induced gene silencing (VIGS) vector for maize based on a naturally maize-infecting cucumber mosaic virus (CMV) strain, ZMBJ-CMV. An infectious clone of ZMBJ-CMV was constructed, and a vascular puncture inoculation method utilizing Agrobacterium was optimized to improve its utility for CMV infection of maize. ZMBJ-CMV was then modified to function as a VIGS vector. The ZMBJ-CMV vector induced mild to moderate symptoms in many maize lines, making it useful for gene function studies in critically important maize cultivars, such as the sequenced reference inbred line B73. Using this CMV VIGS system, expression of two endogenous genes, ZmPDS and ZmIspH, was found to be decreased by 75% and 78%, respectively, compared with non-silenced tissue. Inserts with lengths of 100-300 bp produced the most complete transcriptional and visual silencing phenotypes. Moreover, genes related to autophagy, ZmATG3 and ZmATG8a, were also silenced, and it was found that they function in leaf starch degradation. These results indicate that our ZMBJ-CMV VIGS vector provides a tool for rapid and efficient gene function studies in maize. PMID:26921244

  17. Slow digestion property of octenyl succinic anhydride modified waxy maize starch in the presence of tea polyphenols.

    PubMed

    Peng, Shanli; Xue, Lei; Leng, Xue; Yang, Ruobing; Zhang, Genyi; Hamaker, Bruce R

    2015-03-18

    The in vivo slow digestion property of octenyl succinic anhydride modified waxy corn starch (OSA-starch) in the presence of tea polyphenols (TPLs) was studied. Using a mouse model, the experimental results showed an extended and moderate postprandial glycemic response with a delayed and significantly decreased blood glucose peak of OSA-starch after cocooking with TPLs (5% starch weight base). Further studies revealed an increased hydrodynamic radius of OSA-starch molecules indicating an interaction between OSA-starch and TPLs. Additionally, decreased gelatinization temperature and enthalpy and reduced viscosity and emulsifiability of OSA-starch support their possible complexation to form a spherical OSA-starch-TPLs (OSAT) complex. The moderate and extended postprandial glycemic response is likely caused by decreased activity of mucosal α-glucosidase, which is noncompetitively inhibited by tea catechins released from the complex during digestion. Meanwhile, a significant decrease of malondialdehyde (MDA) and increased DPPH free radical scavenging activity in small intestine tissue demonstrated the antioxidative functional property of the OSAT complex. Thus, the complex of OSAT, acting as a functional carbohydrate material, not only leads to a flattened and prolonged glycemic response but also reduces the oxidative stress, which might be beneficial to health. PMID:25715909

  18. Over-expression of a zeatin O-glucosylation gene in maize leads to growth retardation and tasselseed formation.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To study the effects of cytokinin O-glucosylation in monocots, maize (Zea mays) transformants harboring the ZOG1 gene (encoding a zeatin O-glucosyltransferase from Phaseolus lunatus) under the control of the constitutive ubiquitin (Ubi) promoter were generated. The roots and leaves of the transforma...

  19. Transcriptomic analyses indicate that maize ligule development recapitulates gene expression patterns that occur during lateral organ initiation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Development of multicellular organisms proceeds via the correct interpretation of positional information to establish boundaries that separate developmental fields with distinct identities. The maize (Zea mays) leaf is an ideal system to study plant morphogenesis as it is subdivided into a proximal ...

  20. Diversity of maize kernels from a breeding program for protein quality: II. Correlatively expressed functional amino acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Modern maize breeding and selection for large starchy kernels may have contributed to reduced contents of essential amino acids which represents a serious nutritional problem for humans and animals. The improvement of low levels of essential amino acids, while maintaining high protein content and ha...

  1. TRANSFORMATION EFFICIENCIES AND EXPRESSION PATTERNS OF A SERIES OF TRUNCATED GS1-2 PROMOTER/GUS TRANSGENES IN MAIZE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One isoform of maize glutamine synthetase, encoded by GS1-2, is localized exclusively within the maternal tissues of the developing kernel. In this report, a series GS1-2 promoter/GUS reporter transgenes, progressively truncated from the 5' end of the promoter, were evaluated for transformation eff...

  2. New analysis of a rat feeding study with a genetically modified maize reveals signs of hepatorenal toxicity.

    PubMed

    Séralini, Gilles-Eric; Cellier, Dominique; de Vendomois, Joël Spiroux

    2007-05-01

    Health risk assessment of genetically modified organisms (GMOs) cultivated for food or feed is under debate throughout the world, and very little data have been published on mid- or long-term toxicological studies with mammals. One of these studies performed under the responsibility of Monsanto Company with a transgenic corn MON863 has been subjected to questions from regulatory reviewers in Europe, where it was finally approved in 2005. This necessitated a new assessment of kidney pathological findings, and the results remained controversial. An Appeal Court action in Germany (Münster) allowed public access in June 2005 to all the crude data from this 90-day rat-feeding study. We independently re-analyzed these data. Appropriate statistics were added, such as a multivariate analysis of the growth curves, and for biochemical parameters comparisons between GMO-treated rats and the controls fed with an equivalent normal diet, and separately with six reference diets with different compositions. We observed that after the consumption of MON863, rats showed slight but dose-related significant variations in growth for both sexes, resulting in 3.3% decrease in weight for males and 3.7% increase for females. Chemistry measurements reveal signs of hepatorenal toxicity, marked also by differential sensitivities in males and females. Triglycerides increased by 24-40% in females (either at week 14, dose 11% or at week 5, dose 33%, respectively); urine phosphorus and sodium excretions diminished in males by 31-35% (week 14, dose 33%) for the most important results significantly linked to the treatment in comparison to seven diets tested. Longer experiments are essential in order to indicate the real nature and extent of the possible pathology; with the present data it cannot be concluded that GM corn MON863 is a safe product. PMID:17356802

  3. Expression of the maize ZmGF14-6 gene in rice confers tolerance to drought stress while enhancing susceptibility to pathogen infection.

    PubMed

    Campo, Sonia; Peris-Peris, Cristina; Montesinos, Laura; Peñas, Gisela; Messeguer, Joaquima; San Segundo, Blanca

    2012-01-01

    14-3-3 proteins are found in all eukaryotes where they act as regulators of diverse signalling pathways associated with a wide range of biological processes. In this study the functional characterization of the ZmGF14-6 gene encoding a maize 14-3-3 protein is reported. Gene expression analyses indicated that ZmGF14-6 is up-regulated by fungal infection and salt treatment in maize plants, whereas its expression is down-regulated by drought stress. It is reported that rice plants constitutively expressing ZmGF14-6 displayed enhanced tolerance to drought stress which was accompanied by a stronger induction of drought-associated rice genes. However, rice plants expressing ZmGF14-6 either in a constitutive or under a pathogen-inducible regime showed a higher susceptibility to infection by the fungal pathogens Fusarium verticillioides and Magnaporthe oryzae. Under infection conditions, a lower intensity in the expression of defence-related genes occurred in ZmGF14-6 rice plants. These findings support that ZmGF14-6 positively regulates drought tolerance in transgenic rice while negatively modulating the plant defence response to pathogen infection. Transient expression assays of fluorescently labelled ZmGF14-6 protein in onion epidermal cells revealed a widespread distribution of ZmGF14-6 in the cytoplasm and nucleus. Additionally, colocalization experiments of fluorescently labelled ZmGF14-6 with organelle markers, in combination with cell labelling with the endocytic tracer FM4-64, revealed a subcellular localization of ZmGF14-6 in the early endosomes. Taken together, these results improve our understanding of the role of ZmGF14-6 in stress signalling pathways, while indicating that ZmGF14-6 inversely regulates the plant response to biotic and abiotic stresses. PMID:22016430

  4. Dynamic expression of chromatin modifiers during developmental transitions in mouse preimplantation embryos

    PubMed Central

    Nestorov, Peter; Hotz, Hans-Rudolf; Liu, Zichuan; Peters, Antoine H.F.M.

    2015-01-01

    During mouse preimplantation development, major changes in cell fate are accompanied by extensive alterations of gene expression programs. Embryos first transition from a maternal to zygotic program and subsequently specify the pluripotent and the trophectodermal cell lineages. These processes are regulated by key transcription factors, likely in cooperation with chromatin modifiers that control histone and DNA methylation. To characterize the spatiotemporal expression of chromatin modifiers in relation to developmental transitions, we performed gene expression profiling of 156 genes in individual oocytes and single blastomeres of developing mouse embryos until the blastocyst stage. More than half of the chromatin modifiers displayed either maternal or zygotic expression. We also detected lineage-specific expression of several modifiers, including Ezh1, Prdm14, Scmh1 and Tet1 underscoring possible roles in cell fate decisions. Members of the SET-domain containing SMYD family showed differential gene expression during preimplantation development. We further observed co-expression of genes with opposing biochemical activities, such as histone methyltransferases and demethylases, suggesting the existence of a dynamic chromatin steady-state during preimplantation development. PMID:26403153

  5. Plasmodium falciparum var gene expression is modified by host immunity

    PubMed Central

    Warimwe, George M.; Keane, Thomas M.; Fegan, Gregory; Musyoki, Jennifer N.; Newton, Charles R. J. C.; Pain, Arnab; Berriman, Matthew; Marsh, Kevin; Bull, Peter C.

    2009-01-01

    Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is a potentially important family of immune targets, which play a central role in the host–parasite interaction by binding to various host molecules. They are encoded by a diverse family of genes called var, of which there are ≈60 copies in each parasite genome. In sub-Saharan Africa, although P. falciparum infection occurs throughout life, severe malarial disease tends to occur only in childhood. This could potentially be explained if (i) PfEMP1 variants differ in their capacity to support pathogenesis of severe malaria and (ii) this capacity is linked to the likelihood of each molecule being recognized and cleared by naturally acquired antibodies. Here, in a study of 217 Kenyan children with malaria, we show that expression of a group of var genes “cys2,” containing a distinct pattern of cysteine residues, is associated with low host immunity. Expression of cys2 genes was associated with parasites from young children, those with severe malaria, and those with a poorly developed antibody response to parasite-infected erythrocyte surface antigens. Cys-2 var genes form a minor component of all genomic var repertoires analyzed to date. Therefore, the results are compatible with the hypothesis that the genomic var gene repertoire is organized such that PfEMP1 molecules that confer the most virulence to the parasite tend also to be those that are most susceptible to the development of host immunity. This may help the parasite to adapt effectively to the development of host antibodies through modification of the host–parasite relationship. PMID:20018734

  6. Modified expression of surface glyconjugates in stored human platelets

    SciTech Connect

    Dhar, A.; Ganguly, P.

    1987-05-01

    Platelets are anucleated cells which play an important part in blood coagulation and thrombosis. These cells may be stored in the blood bank for only 4/5 days. In order to improve the storage of platelets, it is essential to first understand the changes in these cells due to storage. In this work, human platelets were stored in autologous plasma at 4/sup 0/ or 22/sup 0/ and their surface changes were monitored with three lectins - wheat germ afflutinin (WGA), concanavalin A (Con A) and lentil lectin (LL). Blood was drawn from healthy donors and platelet rich plasma (PRP) was collected by slow speed centrifugation. Platelets stored at either temperature for different times showed increased sensitivity to agglutination by WGA after 34-48 hrs. Lectins, Con A and LL, which were not agglutinating to fresh platelets readily caused agglutination after 48-72 hrs. The platelets stored for 25 hrs or longer period were insensitive to thrombin but showed enhanced aggregation with WGA. Labelling of surface glycoconjugates of stored platelets with /sup 3/H-boro-hydride revealed progressive loss of a glycoprotein of Mr 150,000 (GPIb infinity) together with the appearance of components of Mr 69,000; Mr 60,000; Mr 25,000. New high molecular weight glycoproteins were also detected only in stored platelets. The author studies clearly indicate that modification or altered expression of platelets surface glycoproteins may be one factor of storage related dysfunction of platelets.

  7. Comparison of drought stress response and gene expression between a GM maize variety and a near-isogenic non-GM variety.

    PubMed

    Gullì, Mariolina; Salvatori, Elisabetta; Fusaro, Lina; Pellacani, Claudia; Manes, Fausto; Marmiroli, Nelson

    2015-01-01

    Maize MON810, grown and commercialised worldwide, is the only cultivated GM event in the EU. Maize MON810, variety DKC6575, and the corresponding near-isogenic line Tietar were studied in different growth conditions, to compare their behaviour in response to drought. Main photosynthetic parameters were significantly affected by drought stress in both GM and non-GM varieties to a similar extent. Though DKC6575 (GM) had a greater sensitivity in the early phase of stress response as compared with Tietar (non-GM), after six days of stress they behaved similarly, and both varieties recovered from stress damage. Profiling gene expression in water deficit regimes and in a generalised drought stress condition showed an up-regulation of many stress-responsive genes, but a greater number of differentially expressed genes was observed in Tietar, with genes belonging to transcription factor families and genes encoding heat shock proteins, late embryogenesis abundant proteins and detoxification enzymes. Since induction of these genes have been indicated from the literature as typical of stress responses, their activation in Tietar rather than in DKC6575 may be reminiscent of a more efficient response to drought. DKC6575 was also analysed for the expression of the transgene CryIAb (encoding the delta-endotoxin insecticidal protein) in water deficit conditions. In all the experiments, the CryIAb transcript was not influenced by drought stress, but was expressed at a constant level. This suggests that though possessing a different pattern of sensitivity to stress, the GM variety maintains the same expression level for the transgene. PMID:25692547

  8. Comparison of Drought Stress Response and Gene Expression between a GM Maize Variety and a Near-Isogenic Non-GM Variety

    PubMed Central

    Gullì, Mariolina; Salvatori, Elisabetta; Fusaro, Lina; Pellacani, Claudia; Manes, Fausto; Marmiroli, Nelson

    2015-01-01

    Maize MON810, grown and commercialised worldwide, is the only cultivated GM event in the EU. Maize MON810, variety DKC6575, and the corresponding near-isogenic line Tietar were studied in different growth conditions, to compare their behaviour in response to drought. Main photosynthetic parameters were significantly affected by drought stress in both GM and non-GM varieties to a similar extent. Though DKC6575 (GM) had a greater sensitivity in the early phase of stress response as compared with Tietar (non-GM), after six days of stress they behaved similarly, and both varieties recovered from stress damage. Profiling gene expression in water deficit regimes and in a generalised drought stress condition showed an up-regulation of many stress-responsive genes, but a greater number of differentially expressed genes was observed in Tietar, with genes belonging to transcription factor families and genes encoding heat shock proteins, late embryogenesis abundant proteins and detoxification enzymes. Since induction of these genes have been indicated from the literature as typical of stress responses, their activation in Tietar rather than in DKC6575 may be reminiscent of a more efficient response to drought. DKC6575 was also analysed for the expression of the transgene CryIAb (encoding the delta-endotoxin insecticidal protein) in water deficit conditions. In all the experiments, the CryIAb transcript was not influenced by drought stress, but was expressed at a constant level. This suggests that though possessing a different pattern of sensitivity to stress, the GM variety maintains the same expression level for the transgene. PMID:25692547

  9. Functional expression of miraculin, a taste-modifying protein in Escherichia coli.

    PubMed

    Matsuyama, Tomomi; Satoh, Makiko; Nakata, Rieko; Aoyama, Takashi; Inoue, Hiroyasu

    2009-04-01

    Miraculin isolated from red berries of Richadella dulcifica, a native shrub of West Africa, has the unusual property of modifying a sour taste into a sweet one. This homodimer protein consists of two glycosylated polypeptides that are cross-linked by a disulfide bond. Recently, functional expression of miraculin was reported in host cells with the ability to glycosylate proteins, such as lettuce, tomato and the microbe Aspergillus oryzae, but not Escherichia coli. Thus, a question remains as to whether glycosylation of miraculin is essential for its taste-modifying properties. Here we show that recombinant miraculin expressed in E. coli has taste-modifying properties as a homodimer, not as a monomer, indicating that glycosylation is not essential for the taste-modifying property. PMID:19122203

  10. Functional expression of the taste-modifying protein, miraculin, in transgenic lettuce.

    PubMed

    Sun, Hyeon-Jin; Cui, Min-Long; Ma, Biao; Ezura, Hiroshi

    2006-01-23

    Taste-modifying proteins are a natural alternative to artificial sweeteners and flavor enhancers and have been used in some cultures for centuries. The taste-modifying protein, miraculin, has the unusual property of being able to modify a sour taste into a sweet taste. Here, we report the use of a plant expression system for the production of miraculin. A synthetic gene encoding miraculin was placed under the control of constitutive promoters and transferred to lettuce. Expression of this gene in transgenic lettuce resulted in the accumulation of significant amounts of miraculin protein in the leaves. The miraculin expressed in transgenic lettuce possessed sweetness-inducing activity. These results demonstrate that the production of miraculin in edible plants can be a good alternative strategy to enhance the availability of this protein. PMID:16406368

  11. Expression of trehalose-6-phosphate phosphatase in maize ears improves yield in well-watered and drought conditions.

    PubMed

    Nuccio, Michael L; Wu, Jeff; Mowers, Ron; Zhou, Hua-Ping; Meghji, Moez; Primavesi, Lucia F; Paul, Matthew J; Chen, Xi; Gao, Yan; Haque, Emdadul; Basu, Shib Sankar; Lagrimini, L Mark

    2015-08-01

    Maize, the highest-yielding cereal crop worldwide, is particularly susceptible to drought during its 2- to 3-week flowering period. Many genetic engineering strategies for drought tolerance impinge on plant development, reduce maximum yield potential or do not translate from laboratory conditions to the field. We overexpressed a gene encoding a rice trehalose-6-phosphate phosphatase (TPP) in developing maize ears using a floral promoter. This reduced the concentration of trehalose-6-phosphate (T6P), a sugar signal that regulates growth and development, and increased the concentration of sucrose in ear spikelets. Overexpression of TPP increased both kernel set and harvest index. Field data at several sites and over multiple seasons showed that the engineered trait improved yields from 9% to 49% under non-drought or mild drought conditions, and from 31% to 123% under more severe drought conditions, relative to yields from nontransgenic controls. PMID:26473199

  12. Herbivory of maize by southern corn rootworm induces expression of the major intrinsic protein ZmNIP1;1 and leads to the discovery of a novel aquaporin ZmPIP2;8.

    PubMed

    Lawrence, Susan D; Novak, Nicole G; Xu, Hao; Cooke, Janice E K

    2013-08-01

    Aquaporins channel water and other neutral molecules through cell membranes. Aquaporin gene expression is subject to transcriptional control and can be modulated by factors affecting water balance such as salt, abscisic acid and drought. During infestation of maize by southern corn rootworm (SCR), an insect that chews into and significantly damages maize roots, three maize aquaporins were differentially expressed upon prolonged infestation. Using a brief infestation of maize roots ZmNIP1;1 transcript abundance again increased under infestation while expression of a new aquaporin, ZmPIP2;8 and ZmTIP2;2 expression did not change. Since ZmPIP2;8 has not been described previously, the deduced protein sequence was analyzed in silico and found to contain the hallmarks of plant aquaporins, with a predicted protein structure similar to other functionally characterized PIP2s. NIPs characterized to date have been implicated in facilitating the movement of a variety of small molecules, while TIPs and PIPs often have the capacity to facilitate trans-membrane movement of water. Functional assays (using heterologous expression in Xenopus laevis oocytes) of ZmTIP2;2 and ZmPIP2;8 confirmed that these aquaporins demonstrate water channel capacity. PMID:23673351

  13. Initial Larval Feeding on an Alternate Host Enhances Western Corn Rootworm (Coleoptera: Chrysomelidae) Beetle Emergence on Cry3Bb1-Expressing Maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The potential for rootworm larvae to move between grassy weeds and transgenic maize may be important in resistance management of transgenic rootworm-resistant maize. To determine the impact of initial feeding of rootworm larvae on alternate hosts, followed by switching host to transgenic maize, on ...

  14. Development of multiplex PCR method for simultaneous detection of four events of genetically modified maize: DAS-59122-7, MIR604, MON863 and MON88017.

    PubMed

    Oguchi, Taichi; Onishi, Mari; Mano, Junichi; Akiyama, Hiroshi; Teshima, Reiko; Futo, Satoshi; Furui, Satoshi; Kitta, Kazumi

    2010-01-01

    A novel multiplex PCR method was developed for simultaneous event-specific detection of four events of GM maize, i.e., DAS-59122-7, MIR604, MON88017, and MON863. The single laboratory examination of analytical performance using simulated DNA mixtures containing GM DNA at various concentrations in non-GM DNA suggested that the limits of detection (LOD) of the multiplex PCR method were 0.16% for MON863, MIR604, and MON88017, and 0.078% for DAS-59122-7. We previously developed a nonaplex (9plex) PCR method for eight events of GM maize, i.e., Bt11, Bt176, GA21, MON810, MON863, NK603, T25, and TC1507. Together with the nonaplex PCR method, the newly developed method enabled the detection and identification of eleven GM maize events that are frequently included in commercial GM seed used in Japan. In addition, this combinational analysis may be useful for the identification of combined event products of GM maize. PMID:20595789

  15. Breeding Specialty Starch Maize Using Exotic Genetic Resources for Gene Discovery of Novel Alleles and Modifiers with Materials Generated from the USDA-ARS GEM Project

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Amylomaize VII, a class of High Amylose Maize with at least 70% of the kernel starch composed of the linear amylose polymer, has had numerous food and industrial applications including the manufacturing of biodegradable plastics, adhesives and candies. More recently it has been found to be a signi...

  16. Comparison of Conventional, Modified Single Seed Descent, and Double Haploid Breeding Methods for Maize Inbred Line Development Using GEM Breeding Crosses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Good choice of germplasm, breeding methods, and careful evaluation are essential for maize inbred line and hybrid development. Choice of germplasm is particularly important since it may limit genetic gain given even the best breeding methodology and selection strategies. Exotic germplasm has the pot...

  17. Pyramiding expression of maize genes encoding phosphoenolpyruvate carboxylase (PEPC) and pyruvate orthophosphate dikinase (PPDK) synergistically improve the photosynthetic characteristics of transgenic wheat.

    PubMed

    Zhang, HuiFang; Xu, WeiGang; Wang, HuiWei; Hu, Lin; Li, Yan; Qi, XueLi; Zhang, Lei; Li, ChunXin; Hua, Xia

    2014-09-01

    Using particle bombardment transformation, we introduced maize pepc cDNA encoding phosphoenolpyruvate carboxylase (PEPC) and ppdk cDNA encoding pyruvate orthophosphate dikinase (PPDK) into the C3 crop wheat to generate transgenic wheat lines carrying cDNA of pepc (PC lines), ppdk (PK lines) or both (PKC lines). The integration, transcription, and expression of the foreign genes were confirmed by Southern blot, Real-time quantitative reverse transcription PCR (Q-RT-PCR), and Western blot analysis. Q-RT-PCR results indicated that the average relative expression levels of pepc and ppdk in the PKC lines reached 10 and 4.6, respectively, compared to their expressions in untransformed plants (set to 1). The enzyme activities of PEPC and PPDK in the PKC lines were 4.3- and 2.1-fold higher, respectively, than in the untransformed control. The maximum daily net photosynthetic rates of the PKC, PC, and PK lines were enhanced by 26.4, 13.3, and 4.5%, respectively, whereas the diurnal accumulations of photosynthesis were 21.3, 13.9, and 6.9%, respectively, higher than in the control. The Fv/Fm of the transgenic plants decreased less than in the control under high temperature and high light conditions (2 weeks after anthesis), suggesting that the transgenic wheat transports more absorbed light energy into a photochemical reaction. The exogenous maize C4-specific pepc gene was more effective than ppdk at improving the photosynthetic performance and yield characteristics of transgenic wheat, while the two genes showed a synergistic effect when they were transformed into the same genetic background, because the PKC lines exhibited improved photosynthetic and physiological traits. PMID:24595619

  18. Reinventing MaizeGDB

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Maize Database (MaizeDB) to the Maize Genetics and Genomics Database (MaizeGDB) turns 20 this year, and such a significant milestone must be celebrated! With the release of the B73 reference sequence and more sequenced genomes on the way, the maize community needs to address various opportunitie...

  19. Expression of modified gene encoding functional human alpha-1-antitrypsin protein in transgenic tomato plants.

    PubMed

    Agarwal, Saurabh; Singh, Rahul; Sanyal, Indraneel; Amla, D V

    2008-10-01

    Transgenic plants offer promising alternative for large scale, sustainable production of safe, functional, recombinant proteins of therapeutic and industrial importance. Here, we report the expression of biologically active human alpha-1-antitrypsin in transgenic tomato plants. The 1,182 bp cDNA sequence of human AAT was strategically designed, modified and synthesized to adopt codon usage pattern of dicot plants, elimination of mRNA destabilizing sequences and modifications around 5' and 3' flanking regions of the gene to achieve high-level regulated expression in dicot plants. The native signal peptide sequence was substituted with modified signal peptide sequence of tobacco (Nicotiana tabacum) pathogenesis related protein PR1a, sweet potato (Ipomoea batatas) sporamineA and with dicot-preferred native signal peptide sequence of AAT gene. A dicot preferred translation initiation context sequence, 38 bp alfalfa mosaic virus untranslated region were incorporated at 5' while an endoplasmic reticulum retention signal (KDEL) was incorporated at 3' end of the gene. The modified gene was synthesized by PCR based method using overlapping oligonucleotides. Tomato plants were genetically engineered by nuclear transformation with Agrobacterium tumefaciens harbouring three different constructs pPAK, pSAK and pNAK having modified AAT gene with different signal peptide sequences under the control of CaMV35S duplicated enhancer promoter. Promising transgenic plants expressing recombinant AAT protein upto 1.55% of total soluble leaf protein has been developed and characterized. Plant-expressed recombinant AAT protein with molecular mass of around approximately 50 kDa was biologically active, showing high specific activity and efficient inhibition of elastase activity. The enzymatic deglycosylation established proper glycosylation of the plant-expressed recombinant AAT protein in contrast to unglycosylated rAAT expressed in E. coli ( approximately 45 kDa). Our results demonstrate

  20. A Mutator Transposon Insertion Is Associated With Ectopic Expression of a Tandemly Repeated Multicopy Myb Gene pericarp color1 of Maize

    PubMed Central

    Robbins, Michael L.; Sekhon, Rajandeep S.; Meeley, Robert; Chopra, Surinder

    2008-01-01

    The molecular basis of tissue-specific pigmentation of maize carrying a tandemly repeated multicopy allele of pericarp color1 (p1) was examined using Mutator (Mu) transposon-mediated mutagenesis. The P1-wr allele conditions a white or colorless pericarp and a red cob glumes phenotype. However, a Mu-insertion allele, designated as P1-wr-mum6, displayed an altered phenotype that was first noted as occasional red stripes on pericarp tissue. This gain-of-pericarp-pigmentation phenotype was heritable, yielding families that displayed variable penetrance and expressivity. In one fully penetrant family, deep red pericarp pigmentation was observed. Several reports on Mu suppressible alleles have shown that Mu transposons can affect gene expression by mechanisms that depend on transposase activity. Conversely, the P1-wr-mum6 phenotype is not affected by transposase activity. The increased pigmentation was associated with elevated mRNA expression of P1-wr-mum6 copy (or copies) that was uninterrupted by the transposons. Genomic bisulfite sequencing analysis showed that the elevated expression was associated with hypomethylation of a floral-specific enhancer that is ∼4.7 kb upstream of the Mu1 insertion site and may be proximal to an adjacent repeated copy. We propose that the Mu1 insertion interferes with the DNA methylation and related chromatin packaging of P1-wr, thereby inducing expression from gene copy (or copies) that is otherwise suppressed. PMID:18430921

  1. Maize: Overview

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize is an important cereal crop that is well-suited to industrial agriculture, both in grain production and in grain utilization. Starch, protein and oil are the three major components of the grain. Several processing methods yield many different food ingredients. In addition, whole grain is pr...

  2. Silencing of Inducible Immunoproteasome Subunit Expression by Chemically Modified siRNA and shRNA.

    PubMed

    Gvozdeva, Olga V; Prassolov, Vladimir S; Zenkova, Marina A; Vlassov, Valentin V; Chernolovskaya, Elena L

    2016-08-01

    Overexpression of inducible subunits of immunoproteasome is related to pathogenesis of some chronic diseases. Specific inhibition of the immunosubunits may be used for the treatment of these diseases and RNA interference is one of the potent methods used in this area. We designed 2'-O-methyl modified siRNAs with selectively protected nuclease-sensitive sites, which efficiently silence LMP2, LMP7, and MECL-1 genes expression. To provide stable long-lasting inhibition of target genes, short-hairpin RNAs (shRNA) expressed by lentiviral vectors were constructed. Our results demonstrated that chemically modified siRNAs inhibited the expression of target genes with similar efficiency or with efficiency exceeding that of corresponding shRNAs and provide silencing effect for 5 days. PMID:27351110

  3. Effect of Stacked Insecticidal Cry Proteins from Maize Pollen on Nurse Bees (Apis mellifera carnica) and Their Gut Bacteria

    PubMed Central

    Härtel, Stephan; Näther, Astrid; Dohrmann, Anja B.; Steffan-Dewenter, Ingolf; Tebbe, Christoph C.

    2013-01-01

    Honey bee pollination is a key ecosystem service to nature and agriculture. However, biosafety research on genetically modified crops rarely considers effects on nurse bees from intact colonies, even though they receive and primarily process the largest amount of pollen. The objective of this study was to analyze the response of nurse bees and their gut bacteria to pollen from Bt maize expressing three different insecticidal Cry proteins (Cry1A.105, Cry2Ab2, and Cry3Bb1). Naturally Cry proteins are produced by bacteria (Bacillus thuringiensis). Colonies of Apis mellifera carnica were kept during anthesis in flight cages on field plots with the Bt maize, two different conventionally bred maize varieties, and without cages, 1-km outside of the experimental maize field to allow ad libitum foraging to mixed pollen sources. During their 10-days life span, the consumption of Bt maize pollen had no effect on their survival rate, body weight and rates of pollen digestion compared to the conventional maize varieties. As indicated by ELISA-quantification of Cry1A.105 and Cry3Bb1, more than 98% of the recombinant proteins were degraded. Bacterial population sizes in the gut were not affected by the genetic modification. Bt-maize, conventional varieties and mixed pollen sources selected for significantly different bacterial communities which were, however, composed of the same dominant members, including Proteobacteria in the midgut and Lactobacillus sp. and Bifidobacterium sp. in the hindgut. Surprisingly, Cry proteins from natural sources, most likely B. thuringiensis, were detected in bees with no exposure to Bt maize. The natural occurrence of Cry proteins and the lack of detectable effects on nurse bees and their gut bacteria give no indication for harmful effects of this Bt maize on nurse honey bees. PMID:23533634

  4. Ectopic Expression of Rubisco Subunits in Maize Mesophyll Cells Does Not Overcome Barriers to Cell Type-Specific Accumulation1[C][W][OA

    PubMed Central

    Wostrikoff, Katia; Clark, Aimee; Sato, Shirley; Clemente, Tom; Stern, David

    2012-01-01

    In maize (Zea mays), Rubisco accumulates in bundle sheath but not mesophyll chloroplasts, but the mechanisms that underlie cell type-specific expression are poorly understood. To explore the coordinated expression of the chloroplast rbcL gene, which encodes the Rubisco large subunit (LS), and the two nuclear RBCS genes, which encode the small subunit (SS), RNA interference was used to reduce RBCS expression. This resulted in Rubisco deficiency and was correlated with translational repression of rbcL. Thus, as in C3 plants, LS synthesis depends on the presence of its assembly partner SS. To test the hypothesis that the previously documented transcriptional repression of RBCS in mesophyll cells is responsible for repressing LS synthesis in mesophyll chloroplasts, a ubiquitin promoter-driven RBCS gene was expressed in both bundle sheath and mesophyll cells. This did not lead to Rubisco accumulation in the mesophyll, suggesting that LS synthesis is impeded even in the presence of ectopic SS expression. To attempt to bypass this putative mechanism, a ubiquitin promoter-driven nuclear version of the rbcL gene was created, encoding an epitope-tagged LS that was expressed in the presence or absence of the Ubi-RBCS construct. Both transgenes were robustly expressed, and the tagged LS was readily incorporated into Rubisco complexes. However, neither immunolocalization nor biochemical approaches revealed significant accumulation of Rubisco in mesophyll cells, suggesting a continuing cell type-specific impairment of its assembly or stability. We conclude that additional cell type-specific factors limit Rubisco expression to bundle sheath chloroplasts. PMID:22744982

  5. Effects of drought on gene expression in maize reproductive and leaf meristem tissue revealed by RNA-Seq.

    PubMed

    Kakumanu, Akshay; Ambavaram, Madana M R; Klumas, Curtis; Krishnan, Arjun; Batlang, Utlwang; Myers, Elijah; Grene, Ruth; Pereira, Andy

    2012-10-01

    Drought stress affects cereals especially during the reproductive stage. The maize (Zea mays) drought transcriptome was studied using RNA-Seq analysis to compare drought-treated and well-watered fertilized ovary and basal leaf meristem tissue. More drought-responsive genes responded in the ovary compared with the leaf meristem. Gene Ontology enrichment analysis revealed a massive decrease in transcript abundance of cell division and cell cycle genes in the drought-stressed ovary only. Among Gene Ontology categories related to carbohydrate metabolism, changes in starch and Suc metabolism-related genes occurred in the ovary, consistent with a decrease in starch levels, and in Suc transporter function, with no comparable changes occurring in the leaf meristem. Abscisic acid (ABA)-related processes responded positively, but only in the ovaries. Related responses suggested the operation of low glucose sensing in drought-stressed ovaries. The data are discussed in the context of the susceptibility of maize kernel to drought stress leading to embryo abortion and the relative robustness of dividing vegetative tissue taken at the same time from the same plant subjected to the same conditions. Our working hypothesis involves signaling events associated with increased ABA levels, decreased glucose levels, disruption of ABA/sugar signaling, activation of programmed cell death/senescence through repression of a phospholipase C-mediated signaling pathway, and arrest of the cell cycle in the stressed ovary at 1 d after pollination. Increased invertase levels in the stressed leaf meristem, on the other hand, resulted in that tissue maintaining hexose levels at an "unstressed" level, and at lower ABA levels, which was correlated with successful resistance to drought stress. PMID:22837360

  6. An upstream open reading frame represses expression of Lc, a member of the R/B family of maize transcriptional activators

    SciTech Connect

    Damiani, R.D. Jr.; Wessler, S.R. )

    1993-09-01

    The R/B genes of maize encode a family of basic helix-loop-helix proteins that determine where and when the anthocyanin-pigment pathway will be expressed in the plant. Previous studies showed that allelic diversity among family members reflects differences in gene expression, specifically in transcription initiation. The authors present evidence that the R gene Lc is under translational control. They demonstrate that the 235-nt transcript leader of Lc represses expression 25- to 30-fold in an in vivo assay. Repression is mediated by the presence in cis of a 38-codon upstream open reading frame. Furthermore, the coding capacity of the upstream open reading frame influences the magnitude of repression. It is proposed that translational control does not contribute to tissue specificity but prevents overexpression of the Lc protein. The diversity of promoter and 5' untranslated leader sequences among the R/B genes provides an opportunity to study the coevolution of transcriptional and translational mechanisms of gene regulation. 36 refs., 5 figs.

  7. Comparative RNA-Seq Analysis Reveals That Regulatory Network of Maize Root Development Controls the Expression of Genes in Response to N Stress

    PubMed Central

    Zhao, Xiongwei; Nie, Shujun; Li, Yuhua; Zhang, Zhiming; Shen, Yaou; Chen, Qi; Lu, Yanli; Lan, Hai; Zhou, Shufeng; Gao, Shibin; Pan, Guangtang; Lin, Haijian

    2016-01-01

    Nitrogen (N) is an essential nutrient for plants, and it directly affects grain yield and protein content in cereal crops. Plant root systems are not only critical for anchorage in the soil, but also for N acquisition. Therefore, genes controlling root development might also affect N uptake by plants. In this study, the responses of nitrogen on root architecture of mutant rtcs and wild-type of maize were investigated by morphological and physiological analysis. Subsequently, we performed a comparative RNA-Seq analysis to compare gene expression profiles between mutant rtcs roots and wild-type roots under different N conditions. We identified 786 co-modulated differentially expressed genes (DEGs) related to root development. These genes participated in various metabolic processes. A co-expression cluster analysis and a cis-regulatory motifs analysis revealed the importance of the AP2-EREBP transcription factor family in the rtcs-dependent regulatory network. Some genotype-specific DEGs contained at least one LBD motif in their promoter region. Further analyses of the differences in gene transcript levels between rtcs and wild-type under different N conditions revealed 403 co-modulated DEGs with distinct functions. A comparative analysis revealed that the regulatory network controlling root development also controlled gene expression in response to N-deficiency. Several AP2-EREBP family members involved in multiple hormone signaling pathways were among the DEGs. These transcription factors might play important roles in the rtcs-dependent regulatory network related to root development and the N-deficiency response. Genes encoding the nitrate transporters NRT2-1, NAR2.1, NAR2.2, and NAR2.3 showed much higher transcript levels in rtcs than in wild-type under normal-N conditions. This result indicated that the LBD gene family mainly functions as transcriptional repressors, as noted in other studies. In summary, using a comparative RNA-Seq-based approach, we identified

  8. Comparative RNA-Seq Analysis Reveals That Regulatory Network of Maize Root Development Controls the Expression of Genes in Response to N Stress.

    PubMed

    He, Xiujing; Ma, Haixia; Zhao, Xiongwei; Nie, Shujun; Li, Yuhua; Zhang, Zhiming; Shen, Yaou; Chen, Qi; Lu, Yanli; Lan, Hai; Zhou, Shufeng; Gao, Shibin; Pan, Guangtang; Lin, Haijian

    2016-01-01

    Nitrogen (N) is an essential nutrient for plants, and it directly affects grain yield and protein content in cereal crops. Plant root systems are not only critical for anchorage in the soil, but also for N acquisition. Therefore, genes controlling root development might also affect N uptake by plants. In this study, the responses of nitrogen on root architecture of mutant rtcs and wild-type of maize were investigated by morphological and physiological analysis. Subsequently, we performed a comparative RNA-Seq analysis to compare gene expression profiles between mutant rtcs roots and wild-type roots under different N conditions. We identified 786 co-modulated differentially expressed genes (DEGs) related to root development. These genes participated in various metabolic processes. A co-expression cluster analysis and a cis-regulatory motifs analysis revealed the importance of the AP2-EREBP transcription factor family in the rtcs-dependent regulatory network. Some genotype-specific DEGs contained at least one LBD motif in their promoter region. Further analyses of the differences in gene transcript levels between rtcs and wild-type under different N conditions revealed 403 co-modulated DEGs with distinct functions. A comparative analysis revealed that the regulatory network controlling root development also controlled gene expression in response to N-deficiency. Several AP2-EREBP family members involved in multiple hormone signaling pathways were among the DEGs. These transcription factors might play important roles in the rtcs-dependent regulatory network related to root development and the N-deficiency response. Genes encoding the nitrate transporters NRT2-1, NAR2.1, NAR2.2, and NAR2.3 showed much higher transcript levels in rtcs than in wild-type under normal-N conditions. This result indicated that the LBD gene family mainly functions as transcriptional repressors, as noted in other studies. In summary, using a comparative RNA-Seq-based approach, we identified

  9. Temozolomide Modifies Caveolin-1 Expression in Experimental Malignant Gliomas In Vitro and In Vivo1

    PubMed Central

    Bruyère, Céline; Abeloos, Laurence; Lamoral-Theys, Delphine; Senetta, Rebecca; Mathieu, Véronique; Le Mercier, Marie; Kast, Richard E; Cassoni, Paola; Vandenbussche, Guy; Kiss, Robert; Lefranc, Florence

    2011-01-01

    BACKGROUND: Caveolin-1 is a protein that displays promotive versus preventive roles in cancer progression according to circumstances. Temozolomide (TMZ) is the standard chemotherapeutic to treat glioma patients. The present work aims to characterizeTMZ-induced effects on caveolin-1 expression in glioma cells. METHODS: Human astroglioma (U373 and T98G) and oligodendroglioma (Hs683) cell lines were used in vitro as well as in vivo orthotopic xenografts (Hs683 and U373) into the brains of immunocompromisedmice. In vitro TMZ-induced effects on protein expression and cellular localization were determined by Western blot analysis and on the actin cytoskeleton organization by means of immunofluorescence approaches. In vivo TMZ-induced effects in caveolin-1 expression in human glioma xenografts were monitored by means of immunohistochemistry. RESULTS: TMZ modified caveolin-1 expression and localization in vitro and in vivo after an administration schedule that slightly, if at all, impaired cell growth characteristics in vitro. Caveolin-1 by itself (at a 100-ng/ml concentration) was able to significantly reduce invasiveness (Boyden chambers) of the three human glioma cell lines. The TMZ-inducedmodification in caveolin-1 expression in flotation/raft compartments was paralleled by altered Cyr61 and β1 integrin expression, two elements that have already been reported to collaborate with caveolin-1 in regulating glioma cell biology, and all these features led to profound reorganization of the actin cytoskeleton. An experimental Src kinase inhibitor, AZD0530, almost completely antagonized the TMZ-induced modulation in caveolin-1 expression. CONCLUSION: TMZ modifies caveolin-1 expression in vitro and in vivo in glioma cells, a feature that directly affects glioma cell migration properties. PMID:21461172

  10. Molecular Genetics of Mitochondrial Biogenesis in Maize.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mitochondrial genome encodes proteins essential for mitochondrial respiration and ATP synthesis. Nuclear gene products, however, are required for the expression of mitochondrial genes and the elaboration of functional mitochondrial protein complexes. We are exploiting a unique collection of maiz...

  11. Impact of Bt maize pollen (MON810) on lepidopteran larvae living on accompanying weeds.

    PubMed

    Gathmann, Achim; Wirooks, Ludger; Hothorn, Ludwig A; Bartsch, Detlef; Schuphan, Ingolf

    2006-08-01

    Environmental risks of Bt maize, particularly pollen drift from Bt maize, were assessed for nontarget lepidopteran larvae in maize field margins. In our experimental approach, we carried out 3-year field trials on 6 ha total. Three treatments were used in a randomized block design with eight replications resulting in 24 plots: (i) near-isogenic control variety without insecticide (control), (ii) near-isogenic control variety with chemical insecticide (Baytroid) and (iii) Bt maize expressing the recombinant toxin. We established a weed strip (20 x 1 m) in every plot consisting of a Chenopodium album (goosefoot)/Sinapis alba (mustard) mixture. In these strips we measured diversity and abundance of lepidopteran larvae during maize bloom and pollen shed. C. album hosted five species but all in very low densities; therefore data were not suitable for statistical analysis. S. alba hosted nine species in total. Most abundant were Plutella xylostella and Pieris rapae. For these species no differences were detected between the Bt treatment and the control, but the chemical insecticide treatment reduced larval abundance significantly. Conclusions regarding experimental methodology and results are discussed in regard to environmental risk assessment and monitoring of genetically modified organisms. PMID:16842436

  12. Development of Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) on pollen from Bt-transgenic and conventional maize.

    PubMed

    Meissle, Michael; Zünd, Jan; Waldburger, Mario; Romeis, Jörg

    2014-01-01

    Maize (Zea mays) pollen is highly nutritious and can be used by predatory arthropods to supplement or replace a carnivorous diet. We demonstrate that maize pollen can be utilized by larvae of the green lacewing, Chrysoperla carnea (Neuroptera: Chrysopidae) under laboratory conditions. Complete development on maize pollen was not possible, but 25% of neonates reached the third instar. When only one instar was fed with pollen and the other two instars with eggs of Ephestia kuehniella (Lepidoptera: Pyralidae), 58-87% of the larvae reached the pupal stage. The experiments included pollen produced by nine cultivars: three genetically modified (GM) cultivars expressing the Bacillus thuringiensis proteins Cry1Ab or Cry3Bb1, their corresponding non-transformed near-isolines, and three conventional cultivars. Maize cultivars were grown in two batches in a glasshouse. Their pollen differed by up to 59% in total protein content, 25% in C:N ratio, and 14% in grain diameter, but the differences were inconsistent and depended on the batch. Lacewing performance was not affected by maize cultivar. For environmental risk assessment of GM plants, in planta studies must consider the variability among conventional cultivars, individual plants, batches, and environmental conditions when evaluating the ecological significance of differences observed between GM and near-isolines. PMID:25082074

  13. Plastin 3 Expression Does Not Modify Spinal Muscular Atrophy Severity in the ∆7 SMA Mouse

    PubMed Central

    Wang, Xueyong; Le, Thanh T.; Le, Hao T.; Beattie, Christine E.; Rich, Mark M.; Burghes, Arthur H. M.

    2015-01-01

    Spinal muscular atrophy is caused by loss of the SMN1 gene and retention of SMN2. The SMN2 copy number inversely correlates with phenotypic severity and is a modifier of disease outcome. The SMN2 gene essentially differs from SMN1 by a single nucleotide in exon 7 that modulates the incorporation of exon 7 into the final SMN transcript. The majority of the SMN2 transcripts lack exon 7 and this leads to a SMN protein that does not effectively oligomerize and is rapidly degraded. However the SMN2 gene does produce some full-length SMN and the SMN2 copy number along with how much full-length SMN the SMN2 gene makes correlates with severity of the SMA phenotype. However there are a number of discordant SMA siblings that have identical haplotypes and SMN2 copy number yet one has a milder form of SMA. It has been suggested that Plastin3 (PLS3) acts as a sex specific phenotypic modifier where increased expression of PLS3 modifies the SMA phenotype in females. To test the effect of PLS3 overexpression we have over expressed full-length PLS3 in SMA mice. To ensure no disruption of functionality or post-translational processing of PLS3 we did not place a tag on the protein. PLS3 protein was expressed under the Prion promoter as we have shown previously that SMN expression under this promoter can rescue SMA mice. High levels of PLS3 mRNA were expressed in motor neurons along with an increased level of PLS3 protein in total spinal cord, yet there was no significant beneficial effect on the phenotype of SMA mice. Specifically, neither survival nor the fundamental electrophysiological aspects of the neuromuscular junction were improved upon overexpression of PLS3 in neurons. PMID:26134627

  14. Network analysis of maize RNA transport pathway genes associated with maize resistance to aflatoxin accumulation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aspergillus flavus is a pathogenic fungus producing alfatoxins that cause significant economic losses in maize production. This study analyzes the differences in expression levels of maize genes in response to A. flavus infection and aflatoxin accumulation. Identification of defense related genes an...

  15. Allergic sensitization modifies the pulmonary expression of 5-hydroxytryptamine receptors in guinea pigs.

    PubMed

    Córdoba-Rodríguez, Guadalupe; Vargas, Mario H; Ruiz, Víctor; Carbajal, Verónica; Campos-Bedolla, Patricia; Mercadillo-Herrera, Paulina; Arreola-Ramírez, José Luis; Segura-Medina, Patricia

    2016-03-01

    There is mounting evidence that 5-hydroxytryptamine (5-HT) plays a role in asthma. However, scarce information exists about the pulmonary expression of 5-HT receptors and its modification after allergic sensitization. In the present work, we explored the expression of 5-HT1A, 5-HT2A, 5-HT3, 5-HT4, 5-ht5a, 5-HT6, and 5-HT7 receptors in lungs from control and sensitized guinea pigs through qPCR and Western blot. In control animals, mRNA from all receptors was detectable in lung homogenates, especially from 5-HT2A and 5-HT4 receptors. Sensitized animals had decreased mRNA expression of 5-HT2A and 5-HT4 receptors and increased that of 5-HT7 receptor. In contrast, they had increased protein expression of 5-HT2A receptor in bronchial epithelium and of 5-HT4 receptor in lung parenchyma. The degree of airway response to the allergic challenge was inversely correlated with mRNA expression of the 5-HT1A receptor. In summary, our results showed that major 5-HT receptor subtypes are constitutively expressed in the guinea pig lung, and that allergic sensitization modifies the expression of 5-HT2A, 5-HT4, and 5-HT7 receptors. PMID:26657047

  16. Importance of rare taxa for bacterial diversity in the rhizosphere of Bt- and conventional maize varieties

    PubMed Central

    Dohrmann, Anja B; Küting, Meike; Jünemann, Sebastian; Jaenicke, Sebastian; Schlüter, Andreas; Tebbe, Christoph C

    2013-01-01

    Ribosomal 16S rRNA gene pyrosequencing was used to explore whether the genetically modified (GM) Bt-maize hybrid MON 89034 × MON 88017, expressing three insecticidal recombinant Cry proteins of Bacillus thuringiensis, would alter the rhizosphere bacterial community. Fine roots of field cultivated Bt-maize and three conventional maize varieties were analyzed together with coarse roots of the Bt-maize. A total of 547 000 sequences were obtained. Library coverage was 100% at the phylum and 99.8% at the genus rank. Although cluster analyses based on relative abundances indicated no differences at higher taxonomic ranks, genera abundances pointed to variety specific differences. Genera-based clustering depended solely on the 49 most dominant genera while the remaining 461 rare genera followed a different selection. A total of 91 genera responded significantly to the different root environments. As a benefit of pyrosequencing, 79 responsive genera were identified that might have been overlooked with conventional cloning sequencing approaches owing to their rareness. There was no indication of bacterial alterations in the rhizosphere of the Bt-maize beyond differences found between conventional varieties. B. thuringiensis-like phylotypes were present at low abundance (0.1% of Bacteria) suggesting possible occurrence of natural Cry proteins in the rhizospheres. Although some genera indicated potential phytopathogenic bacteria in the rhizosphere, their abundances were not significantly different between conventional varieties and Bt-maize. With an unprecedented sensitivity this study indicates that the rhizosphere bacterial community of a GM maize did not respond abnormally to the presence of three insecticidal proteins in the root tissue. PMID:22791236

  17. The WOPR Protein Ros1 Is a Master Regulator of Sporogenesis and Late Effector Gene Expression in the Maize Pathogen Ustilago maydis

    PubMed Central

    Tollot, Marie; Assmann, Daniela; Becker, Christian; Altmüller, Janine; Dutheil, Julien Y.; Wegner, Carl-Eric; Kahmann, Regine

    2016-01-01

    The biotrophic basidiomycete fungus Ustilago maydis causes smut disease in maize. Hallmarks of the disease are large tumors that develop on all aerial parts of the host in which dark pigmented teliospores are formed. We have identified a member of the WOPR family of transcription factors, Ros1, as major regulator of spore formation in U. maydis. ros1 expression is induced only late during infection and hence Ros1 is neither involved in plant colonization of dikaryotic fungal hyphae nor in plant tumor formation. However, during late stages of infection Ros1 is essential for fungal karyogamy, massive proliferation of diploid fungal cells and spore formation. Premature expression of ros1 revealed that Ros1 counteracts the b-dependent filamentation program and induces morphological alterations resembling the early steps of sporogenesis. Transcriptional profiling and ChIP-seq analyses uncovered that Ros1 remodels expression of about 30% of all U. maydis genes with 40% of these being direct targets. In total the expression of 80 transcription factor genes is controlled by Ros1. Four of the upregulated transcription factor genes were deleted and two of the mutants were affected in spore development. A large number of b-dependent genes were differentially regulated by Ros1, suggesting substantial changes in this regulatory cascade that controls filamentation and pathogenic development. Interestingly, 128 genes encoding secreted effectors involved in the establishment of biotrophic development were downregulated by Ros1 while a set of 70 “late effectors” was upregulated. These results indicate that Ros1 is a master regulator of late development in U. maydis and show that the biotrophic interaction during sporogenesis involves a drastic shift in expression of the fungal effectome including the downregulation of effectors that are essential during early stages of infection. PMID:27332891

  18. The influence of biocomposites containing genetically modified flax fibers on gene expression in rat skeletal muscle.

    PubMed

    Gredes, Tomasz; Kunert-Keil, Christiane; Dominiak, Marzena; Gedrange, Tomasz; Wróbel-Kwiatkowska, Magdalena; Szopa, Jan

    2010-12-01

    In many studies, natural flax fibers have been proven to be resistant and surgically suitable. Genetically modified flax fibers, derived from transgenic flax expressing three bacterial genes for the synthesis of poly-3-hydroxybutyric acid (PHB), have better mechanical properties than unmodified flax fibers. The aim of this study was to examine the biocompatibility of composites containing flax fibers from transgenic polyhydroxybutyrate producing (M50) and control (wt-NIKE) plants in a polylactide (PLA) matrix in rat Musculus latissimus dorsi. For this purpose, effects of biocomposites on the expression of growth factors and osteogenic differentiation, in particular the mRNA expression of vascular endothelial growth factor, insulin like growth factor 1, insulin like growth factor 2, collagen-1, collagen-2 and myostatin, were analyzed using quantitative RT-PCR. The biocomposites did not show any inflammation response after subcutaneous insertion. The results following subcutaneous insertion of PLA alone and PLA-M50 showed no significant changes on the gene expression of all tested genes, whereas PLA-wt-NIKE reduced the mRNA amount of myostatin, VEGFA and IGF2, respectively. It can be asserted that modified flax membranes with PHB and other organic substances have a good biocompatibility to the muscle and they do not disrupt the muscle function. Furthermore, composites from transgenic flax plants producing PHB did not differ from composites of non-transgenic flax plants. PMID:20973615

  19. Identification of trans-dominant modifiers of Prat expression in Drosophila melanogaster.

    PubMed

    Malmanche, Nicolas; Clark, Denise V

    2003-08-01

    The first committed step in the purine de novo synthesis pathway is performed by amidophosphoribosyltransferase (EC 2.4.2.14) or Prat. Drosophila melanogaster Prat is an essential gene with a promoter that lacks a TATA-box and initiator element and has multiple transcription start sites with a predominant start site. To study the regulation of Prat expression in the adult eye, we used the Prat:bw reporter gene, in which the Prat coding region was replaced with the brown (bw) coding region. The pale-orange eye color of a single copy of Prat:bw prompted us to use a multicopy array of Prat:bw that was derived using P transposase mutagenesis and produces a darker-orange eye color in a bw(D); st genetic background. We used a 13-copy array of Prat:bw as a tool to recover dominant EMS-induced mutations that affect the expression of the transgene. After screening 21,000 F(1)s for deviation from the orange eye color, we isolated 23 dominant modifiers: 21 suppressors (1 Y-linked, 5 X-linked, 4 2-linked, and 11 3-linked) and 2 enhancers (1 2-linked and 1 3-linked). Quantification of their effect on endogenous Prat gene expression, using RT-PCR in young adult fly heads, identifies a subset of modifiers that are candidates for genes involved in regulating Prat expression. PMID:12930749

  20. The auxin-deficient defective kernel18 (dek18) mutation alters the expression of seed-specific biosynthethic genes in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The dek18 mutant of maize has decreased auxin content in kernels. Molecular and functional characterization of this mutant line offers the possibility to better understand auxin biology in maize seed development. Seeds of the dek18 mutants are smaller compared to wild type seeds and the vegetative d...

  1. Overexpression of the Maize psbA Gene Enhances Drought Tolerance Through Regulating Antioxidant System, Photosynthetic Capability, and Stress Defense Gene Expression in Tobacco.

    PubMed

    Huo, Yongjin; Wang, Meiping; Wei, Yangyang; Xia, Zongliang

    2015-01-01

    The psbA (encoding D1 protein) plays an important role in protecting photosystem II (PSII) from oxidative damage in higher plants. In our previous study, the role of the psbA from maize (Zea mays. L) in response to SO2 stress was characterized. To date, information about the involvement of the psbA gene in drought response is scarce. Here we found that overexpression (OE) of ZmpsbA showed increased D1 protein abundance and enhanced drought stress tolerance in tobacco. The drought-tolerant phenotypes of the OE lines were accompanied by increases of key antioxidant enzymes SOD, CAT, and POD activities, but decreases of hydrogen peroxide, malondialdehyde, and ion leakage. Further investigation showed that the OE plants had much less reductions than the wild-type in the net photosynthesis rate (Pn), stomatal conductance (Gs), and the maximal photochemical efficiency of PSII (Fv/Fm) during drought stress; indicating that OE of ZmpsbA may alleviate photosynthesis inhibition during drought. qRT-PCR analysis revealed that there was significantly increased expression of NtLEA5, NtERD10C, NtAREB, and NtCDPK2 in ZmpsbA-OE lines. Together, our results indicate that ZmpsbA improves drought tolerance in tobacco possibly by alleviating photosynthesis reduction, reducing reactive oxygen species accumulation and membrane damage, and modulating stress defense gene expression. ZmpsbA could be exploited for engineering drought-tolerant plants in molecular breeding of crops. PMID:26793207

  2. Expression and purification of lacticin Q by small ubiquitin-related modifier fusion in Escherichia coli.

    PubMed

    Ma, Qingshan; Yu, Zhanqiao; Han, Bing; Wang, Qing; Zhang, Rijun

    2012-04-01

    Lacticin Q is a broad-spectrum class II bacteriocin with potential as an alternative to conventional antibiotics. The objective of this study was to produce recombinant lacticin Q using a small ubiquitin-related modifier (SUMO) fusion protein expression system. The 168-bp lacticin Q gene was cloned into the expression vector pET SUMO and transformed into Escherichia coli BL21(DE3). The soluble fusion protein was recovered with a Ni-NTA Sepharose column (95% purity); 130 mg protein was obtained per liter of fermentation culture. The SUMO tag was then proteolytically cleaved from the protein, which was re-applied to the column. Finally, about 32 mg lacticin Q (≥96% purity) was obtained. The recombinant protein exhibited antimicrobial properties similar to that of the native protein, demonstrating that lacticin Q had been successfully expressed by the SUMO fusion system. PMID:22538663

  3. In utero tobacco exposure epigenetically modifies placental CYP1A1 expression.

    PubMed

    Suter, Melissa; Abramovici, Adi; Showalter, Lori; Hu, Min; Shope, Cynthia Do; Varner, Michael; Aagaard-Tillery, Kjersti

    2010-10-01

    The metabolic pathways used by higher-eukaryotic organisms to deal with potentially carcinogenic xenobiotic compounds from tobacco smoke have been well characterized. Carcinogenic compounds such as polycyclic aromatic hydrocarbons are metabolized sequentially in 2 phases: in phase I, CYP1A1 catalyzes conversion into harmful hydrophilic DNA adducts, whereas in phase II, GSTT1 enables excretion via conjugation into polar electrophiles. In an effort to understand susceptibility to in utero tobacco exposure, we previously characterized known metabolic functional polymorphisms and demonstrated that although deletion of fetal GSTT1 significantly modified birth weight in smokers, no polymorphism fully accounted for fetal growth restriction. Because smoking up-regulates CYP1A1 expression, we hypothesized that nonallelic (epigenetic) dysregulation of placental CYP1A1 expression via alterations in DNA methylation (meCpG) may further modify fetal growth. In the present article, we compared placental expression of multiple CYP family members among gravidae and observed significantly increased CYP1A1 expression among smokers relative to controls (4.4-fold, P < .05). To fully characterize CYP1A1 meCpG status, bisulfite modification and sequencing of the entire proximal 1-kilobase promoter (containing 59 CpG sites) were performed. CpG sites immediately proximal to the 5′-xenobiotic response element transcription factor binding element were significantly hypomethylated among smokers (55.6% vs 45.9% meCpG, P = .027), a finding that uniquely correlated with placental gene expression (r = 0.737, P = .007). Thus, in utero tobacco exposure significantly increases placental CYP1A1 expression in association with differential methylation at a critical xenobiotic response element. PMID:20462615

  4. SNORD116 and SNORD115 change expression of multiple genes and modify each other's activity.

    PubMed

    Falaleeva, Marina; Surface, Justin; Shen, Manli; de la Grange, Pierre; Stamm, Stefan

    2015-11-10

    The loss of two gene clusters encoding small nucleolar RNAs, SNORD115 and SNORD116 contribute to Prader-Willi syndrome (PWS), the most common syndromic form of obesity in humans. SNORD115 and SNORD116 are considered to be orphan C/D box snoRNAs (SNORDs) as they do not target rRNAs or snRNAs. SNORD115 exhibits sequence complementarity towards the serotonin receptor 2C, but SNORD116 shows no extended complementarities to known RNAs. To identify molecular targets, we performed genome-wide array analysis after overexpressing SNORD115 and SNORD116 in HEK 293T cells, either alone or together. We found that SNORD116 changes the expression of over 200 genes. SNORD116 mainly changed mRNA expression levels. Surprisingly, we found that SNORD115 changes SNORD116's influence on gene expression. In similar experiments, we compared gene expression in post-mortem hypothalamus between individuals with PWS and aged-matched controls. The synopsis of these experiments resulted in 23 genes whose expression levels were influenced by SNORD116. Together our results indicate that SNORD115 and SNORD116 influence expression levels of multiple genes and modify each other activity. PMID:26220404

  5. Periconceptional undernutrition modifies endocrine profiles and hepatic gene expression in sheep.

    PubMed

    de Brun, V; Meikle, A; Casal, A; Sequeira, M; Contreras-Solís, I; Carriquiry, M; Forcada, F; Sosa, C; Abecia, J A

    2015-08-01

    This study investigated whether a 22-day period of undernutrition (half maintenance) could affect maternal endocrine responses and liver gene expression during early pregnancy (day 7). Thirty-five ewes were fed 1.5 (n = 15) or 0.5 (n = 20) their maintenance requirements and slaughtered on day 7 of the oestrus cycle or pregnancy (oestrus = day 0). Insulin, IGF, leptin and non-esterified fatty acids (NEFA) were determined on days -14, 0 and 7. Transcripts of the IGF family and adipokines receptors were determined in the liver by real-time RT-PCR. Underfed animals presented lower body weight and body condition, greater plasma concentration of NEFA, and lower plasma concentrations of leptin, insulin and IGF1 compared to adequately fed animals. Underfed ewes presented greater hepatic expression of IGFBP2 than well-fed ewes, but tended to have lesser expression of IGFBP5. While no effect of undernutrition on IGFBP4 and ADIPOR2 mRNA expressions was observed, they were increased by pregnancy in underfed animals. This study shows that undernutrition modifies endocrine profiles and hepatic gene expression of IGFBP2 and 5. The pregnancy status increased hepatic gene expression of IGFBP4 and ADIPOR2 mRNA in undernourished ewes. PMID:25319346

  6. Differentially expressed epigenome modifiers, including Aurora kinase A and B, in immune cells of rheumatoid arthritis

    PubMed Central

    Glant, Tibor T.; Besenyei, Timea; Kádár, András; Kurkó, Júlia; Tryniszewska, Beata; Gál, János; Soós, Györgyi; Szekanecz, Zoltán; Hoffmann, Gyula; Block, Joel A.; Katz, Robert S.; Mikecz, Katalin; Rauch, Tibor A.

    2014-01-01

    Objective The aim of this study was to identify epigenetic factors that are implicated in the pathogenesis of rheumatoid arthritis (RA) and to explore the therapeutic potential of the targeted inhibition of these factors. Methods PCR arrays were utilized to investigate the expression profile of genes that encod key epigenetic regulator enzymes. Mononuclear cells from RA patients and mice were monitored for gene expression changes, in association with arthritis development in murine models of RA. Selected genes were further characterized by quantitative real-time PCR, Western blot and flow cytometry methods. The targeted inhibition of the upregulated enzymes was studied in arthritic mice. Results A set of genes with arthritis-specific expression was identified by the PCR arrays. Aurora kinase A and B, both of which were highly expressed in arthritic mice and treatment naïve RA patients, were selected for detailed analysis. Elevated Aurora kinase expression was accompanied with an increased phosphorylation of histone H3, which promotes proliferation of T lymphocytes. Treatment with VX-680, a pan-Aurora kinase inhibitor, promoted B cell apoptosis, provided significant protection against the onset, and attenuated the inflammatory reactions in arthritic mice. Conclusions Arthritis development is accompanied the changes in the expression of a number of epigenome-modifying enzymes. Drug-induced downregulation of the Aurora kinases, among other targets, seems to be sufficient to treat experimental arthritis. Development of new therapeutics that target the Aurora kinases can potentially improve RA management. PMID:23653330

  7. Use of guanidinopropyl-modified siRNAs to silence gene expression.

    PubMed

    Buff, Maximilian C R; Bernhardt, Stefan; Marimani, Musa D; Ely, Abdullah; Engels, Joachim W; Arbuthnot, Patrick

    2015-01-01

    Silencing gene expression by harnessing the RNA interference (RNAi) pathway with short interfering RNAs (siRNAs) has useful analytical and potentially therapeutic application. To augment silencing efficacy of siRNAs, chemical modification has been employed to improve stability, target specificity, and delivery to target tissues. siRNAs incorporating guanidinopropyl (GP) moieties have demonstrated enhanced target gene silencing in cell culture and in vivo models of hepatitis B virus replication. Here we describe the synthesis of GP-modified siRNAs and use of 5' rapid amplification of cDNA ends (5' RACE) to verify an RNAi-mediated mechanism of action of these novel chemically modified siRNAs. PMID:25319654

  8. An analysis of variation in expression of neurofibromatosis (NF) type I (NFI): Evidence for modifying genes

    SciTech Connect

    Easton, D.F.; Ponder, B.A.J. ); Huson, S.M. ); Ponder, M.A. )

    1993-08-01

    Neurofibromatosis (NF) type 1 (NF1) is notable for its variable expression. To determine whether variation in expression has an inherited component, the authors examined 175 individuals in 48 NF families, including six MZ twin pairs. Three quantitative traits were scored - number of cafe-au-lait patches, number of cutaneous neurofibromas, and head circumference; and five binary traits were scored - the presence or absence of plexiform neurofibromas, optic gliomas, scoliosis, epilepsy, and referral for remedial education. For cafe-au-lait patches and neurofibromas, correlation was highest between MZ twins, less high between first-degree relatives, and lower still between more distant relatives. The high correlation between distant relatives suggests that the type of mutation at the NF1 locus itself plays only a minor role. All of the five binary traits, with the exception of plexiformneurofibromas, also showed significant familial clustering. The familial effects for these traits were consistent with polygenic effects, but there were insufficient data to rule out other models, including a significant effect of different NF1 mutations. There was no evidence of any association between the different traits in affected individuals. The authors conclude that the phenotypic expression of NF1 is to a large extent determined by the genotype at other [open quotes]modifying[close quotes] loci and that these modifying genes are trait specific. 22 refs., 8 tabs.

  9. Efficient, Glucose Responsive, and Islet-Specific Transgene Expression by a Modified Rat Insulin Promoter

    PubMed Central

    Chai, Renjie; Chen, Shuyuan; Ding, Jiahuan; Grayburn, Paul A

    2009-01-01

    This study was done to improve efficiency and islet specificity of the rat insulin promoter (RIP). Various rat insulin promoter lengths were prepared and tested in vitro to drive luciferase reporter gene expression in INS1-cells, alpha-cells, acinar cells, ductal cells, and fibroblasts. The CMV promoter was used as a positive control. In addition, the DsRed reporter gene was administered in vivo to rat pancreas by ultrasound-targeted microbubble destruction (UTMD). Confocal microscopy was used to detect the presence and distribution of DsRed within the pancreas after UTMD. A modified RIP3.1 promoter, which includes portions of the insulin gene after its transcription start site is 5-fold more active in INS-1 cells than the full length RIP promoter or the CMV promoter. RIP3.1 is regulated by glucose level and various islet transcription factors in vitro, and exhibits activity in alpha-cells, but not exocrine cells. In vivo delivery of RIP3.1-DsRed resulted in expression of DsRed protein in beta-cells, and to a lesser extent alpha cells under normal glucose conditions. No DsRed signal was present in exocrine pancreas under RIP3.1. A modified rat insulin promoter, RIP3.1, efficiently and specifically directs gene expression to endocrine pancreas. PMID:19727136

  10. Defining the SUMO System in Maize: SUMOylation Is Up-Regulated during Endosperm Development and Rapidly Induced by Stress.

    PubMed

    Augustine, Robert C; York, Samuel L; Rytz, Thérèse C; Vierstra, Richard D

    2016-07-01

    In response to abiotic and biotic challenges, plants rapidly attach small ubiquitin-related modifier (SUMO) to a large collection of nuclear proteins, with studies in Arabidopsis (Arabidopsis thaliana) linking SUMOylation to stress tolerance via its modification of factors involved in chromatin and RNA dynamics. Despite this importance, little is known about SUMOylation in crop species. Here, we describe the plant SUMO system at the phylogenetic, biochemical, and transcriptional levels with a focus on maize (Zea mays). In addition to canonical SUMOs, land plants encode a loosely constrained noncanonical isoform and a variant containing a long extension upstream of the signature β-grasp fold, with cereals also expressing a novel diSUMO polypeptide bearing two SUMO β-grasp domains in tandem. Maize and other cereals also synthesize a unique SUMO-conjugating enzyme variant with more restricted expression patterns that is enzymatically active despite a distinct electrostatic surface. Maize SUMOylation primarily impacts nuclear substrates, is strongly induced by high temperatures, and displays a memory that suppresses subsequent conjugation. Both in-depth transcript and conjugate profiles in various maize organs point to tissue/cell-specific functions for SUMOylation, with potentially significant roles during embryo and endosperm maturation. Collectively, these studies define the organization of the maize SUMO system and imply important functions during seed development and stress defense. PMID:27208252

  11. Screening Maize Germplasm for Resistance to Western and Northern Corn Rootworms (Chrysomelidae: Diabrotica spp.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Corn rootworms (Coleoptera: Chrysomelidae) are devastating pests of maize (Zea mays L.), with a subterranean larval stage that consumes root tissue. To lessen reliance on soil insecticides and provide alternatives for genetically modified maize hybrids, researchers have developed novel maize germpla...

  12. Soluble Invertase Expression Is an Early Target of Drought Stress during the Critical, Abortion-Sensitive Phase of Young Ovary Development in Maize1

    PubMed Central

    Andersen, Mathias Neumann; Asch, Folkard; Wu, Yong; Jensen, Christian Richardt; Næsted, Henrik; Mogensen, Vagn Overgaard; Koch, Karen Elaine

    2002-01-01

    To distinguish their roles in early kernel development and stress, expression of soluble (Ivr2) and insoluble (Incw2) acid invertases was analyzed in young ovaries of maize (Zea mays) from 6 d before (−6 d) to 7 d after pollination (+7 d) and in response to perturbation by drought stress treatments. The Ivr2 soluble invertase mRNA was more abundant than the Incw2 mRNA throughout pre- and early post-pollination development (peaking at +3 d). In contrast, Incw2 mRNAs increased only after pollination. Drought repression of the Ivr2 soluble invertase also preceded changes in Incw2, with soluble activity responding before pollination (−4 d). Distinct profiles of Ivr2 and Incw2 mRNAs correlated with respective enzyme activities and indicated separate roles for these invertases during ovary development and stress. In addition, the drought-induced decrease and developmental changes of ovary hexose to sucrose ratio correlated with activity of soluble but not insoluble invertase. Ovary abscisic acid levels were increased by severe drought only at −6 d and did not appear to directly affect Ivr2 expression. In situ analysis showed localized activity and Ivr2 mRNA for soluble invertase at sites of phloem-unloading and expanding maternal tissues (greatest in terminal vascular zones and nearby cells of pericarp, pedicel, and basal nucellus). This early pattern of maternal invertase localization is clearly distinct from the well-characterized association of insoluble invertase with the basal endosperm later in development. This localization, the shifts in endogenous hexose to sucrose environment, and the distinct timing of soluble and insoluble invertase expression during development and stress collectively indicate a key role and critical sensitivity of the Ivr2 soluble invertase gene during the early, abortion-susceptible phase of development. PMID:12376627

  13. Analysis of gene expression and histone modification between C4 and non-C4 homologous genes of PPDK and PCK in maize.

    PubMed

    Dong, Xiu-Mei; Li, Yuan; Chao, Qing; Shen, Jie; Gong, Xiu-Jie; Zhao, Biligen-Gaowa; Wang, Bai-Chen

    2016-07-01

    More efficient photosynthesis has allowed C4 plants to adapt to more diverse ecosystems (such as hot and arid conditions) than C3 plants. To better understand C4 photosynthesis, we investigated the expression patterns of C4 genes (C4PPDK and PCK1) and their non-C4 homologous genes (CyPPDK1, CyPPDK2, and PCK2) in the different organs of maize (Zea mays). Both C4 genes and non-C4 genes showed organ-dependent expression patterns. The mRNA levels of C4 genes were more abundant in leaf organ than in seeds at 25 days after pollination (DAP), while non-C4 genes were mainly expressed in developing seeds. Further, acetylation of histone H3 lysine 9 (H3K9ac) positively correlates with mRNA levels of C4 genes (C4PPDK and PCK1) in roots, stems, leaves, and seeds at 25 DAP, acetylation of histone H4 lysine 5 (H4K5ac) in the promoter regions of both C4 (C4PPDK and PCK1) and non-C4 genes (CyPPDK1, CyPPDK2, and PCK2) correlated well with their transcripts abundance in stems. In photosynthetic organs (stems and leaves), dimethylation of histone H3 lysine 9 (H3K9me2) negatively correlated with mRNA levels of both C4 and non-C4 genes. Taken together, our data suggest that histone modification was involved in the transcription regulation of both C4 genes and non-C4 genes, which might provide a clue of the functional evolution of C4 genes. PMID:27161567

  14. Enhanced drought tolerance in transgenic rice over-expressing of maize C4 phosphoenolpyruvate carboxylase gene via NO and Ca(2+).

    PubMed

    Qian, Baoyun; Li, Xia; Liu, Xiaolong; Chen, Pingbo; Ren, Chengang; Dai, Chuanchao

    2015-03-01

    We determined the effects of endogenous nitric oxide and Ca(2+) on photosynthesis and gene expression in transgenic rice plants (PC) over-expressing the maize C4pepc gene, which encodes phosphoenolpyruvate carboxylase (PEPC) under drought. In this study, seedlings were subjected to PEG 6000 treatments using PC and wild type (WT; Kitaake). The results showed that, compared with WT, PC had higher relative water content (RWC) and net photosynthetic rate (Pn) under drought. During a 2-day re-watering treatment, Pn recovered faster in PC than in WT. Further analyses showed that, under the drought treatment, the amount of endogenous hydrogen peroxide (H2O2) increased in WT mainly via NADPH oxidase. While in PC, the endogenous nitric oxide (NO) content increased via nitrate reductase and nitric oxide synthase on day 2 of the drought treatment and day 1 of the re-watering treatment. After 2 days of drought treatment, PC also showed higher PEPC activity, calcium content, phospholipase D (PLD) activity, C4-pepc and NAC6 transcript levels, and protein kinase activity as compared with PC without treatment. These changes did not occur in WT. Correlation analysis also proved NO associated with these indicators in PC. Based on these results, there was a particular molecular mechanism of drought tolerance in PC. The mechanism is related to the signaling processes via NO and Ca(2+) involving the protein kinase and the transcription factor, resulted in up-regulation of PEPC activity and its gene expression, such as C4pepc. Some genes encode antioxidant system, cu/zn-sod as well, which promote antioxidant system to clear MDA and superoxide anion radical, thereby conferring drought tolerance. PMID:25460871

  15. Recurrent selection for transgene expression levels in maize results in proxy selection for a native gene with the same promoter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High expression levels of a transgene can be very useful, making a transgene easier to evaluate for safety and efficacy. High expression levels can also increase the economic benefit of the production of high value proteins in transgenic plants. The goal of this research is to determine if recurre...

  16. Strategies for the expression of SUMO-modified target proteins in Escherichia coli.

    PubMed

    Saitoh, Hisato; Uwada, Junsuke; Azusa, Kawasaki

    2009-01-01

    We previously described the establishment of a binary vector system that allows co-expression of SUMO conjugation enzymes and a target protein of interest, leading to efficient SUMO modification and the production of a large amount of recombinant SUMO-modified proteins in Escherichia coli. The advantages of this E. coli expression/modification approach include scalability of experiments, low cost, fast growth, and a lack of proteases that cleave the isopeptide linkage between SUMO and the target protein. Thus, this E. coli method provides a useful alternative to authentic SUMO modification assays, such as in vitro SUMO conjugation and in vivo SUMO modification using baculovirus or mammalian cell culture, that are usually complicated, time-consuming and expensive. PMID:19107420

  17. Maize pan-transcriptome provides novel insights into genome complexity and quantitative trait variation

    PubMed Central

    Jin, Minliang; Liu, Haijun; He, Cheng; Fu, Junjie; Xiao, Yingjie; Wang, Yuebin; Xie, Weibo; Wang, Guoying; Yan, Jianbing

    2016-01-01

    Gene expression variation largely contributes to phenotypic diversity and constructing pan-transcriptome is considered necessary for species with complex genomes. However, the regulation mechanisms and functional consequences of pan-transcriptome is unexplored systematically. By analyzing RNA-seq data from 368 maize diverse inbred lines, we identified almost one-third nuclear genes under expression presence and absence variation, which tend to play regulatory roles and are likely regulated by distant eQTLs. The ePAV was directly used as “genotype” to perform GWAS for 15 agronomic phenotypes and 526 metabolic traits to efficiently explore the associations between transcriptomic and phenomic variations. Through a modified assembly strategy, 2,355 high-confidence novel sequences with total 1.9 Mb lengths were found absent within reference genome. Ten randomly selected novel sequences were fully validated with genomic PCR, including another two NBS_LRR candidates potentially affect flavonoids and disease-resistance. A simulation analysis suggested that the pan-transcriptome of the maize whole kernel is approaching a maximum value of 63,000 genes, and through developing two test-cross populations and surveying several most important yield traits, the dispensable genes were shown to contribute to heterosis. Novel perspectives and resources to discover maize quantitative trait variations were provided to better understand the kernel regulation networks and to enhance maize breeding. PMID:26729541

  18. Maize pan-transcriptome provides novel insights into genome complexity and quantitative trait variation.

    PubMed

    Jin, Minliang; Liu, Haijun; He, Cheng; Fu, Junjie; Xiao, Yingjie; Wang, Yuebin; Xie, Weibo; Wang, Guoying; Yan, Jianbing

    2016-01-01

    Gene expression variation largely contributes to phenotypic diversity and constructing pan-transcriptome is considered necessary for species with complex genomes. However, the regulation mechanisms and functional consequences of pan-transcriptome is unexplored systematically. By analyzing RNA-seq data from 368 maize diverse inbred lines, we identified almost one-third nuclear genes under expression presence and absence variation, which tend to play regulatory roles and are likely regulated by distant eQTLs. The ePAV was directly used as "genotype" to perform GWAS for 15 agronomic phenotypes and 526 metabolic traits to efficiently explore the associations between transcriptomic and phenomic variations. Through a modified assembly strategy, 2,355 high-confidence novel sequences with total 1.9 Mb lengths were found absent within reference genome. Ten randomly selected novel sequences were fully validated with genomic PCR, including another two NBS_LRR candidates potentially affect flavonoids and disease-resistance. A simulation analysis suggested that the pan-transcriptome of the maize whole kernel is approaching a maximum value of 63,000 genes, and through developing two test-cross populations and surveying several most important yield traits, the dispensable genes were shown to contribute to heterosis. Novel perspectives and resources to discover maize quantitative trait variations were provided to better understand the kernel regulation networks and to enhance maize breeding. PMID:26729541

  19. A recombinant canine distemper virus expressing a modified rabies virus glycoprotein induces immune responses in mice.

    PubMed

    Li, Zhili; Wang, Jigui; Yuan, Daoli; Wang, Shuang; Sun, Jiazeng; Yi, Bao; Hou, Qiang; Mao, Yaping; Liu, Weiquan

    2015-06-01

    Canine distemper virus (CDV) and rabies virus (RV) are two important pathogens of the dog. CDV, a member of the morbillivirus genus, has shown promise as an expression vector. The glycoprotein from RV is a main contributor to protective immunity and capable of eliciting the production of virus-neutralizing antibodies. In this study, we recovered an attenuated strain of canine distemper virus and constructed a recombinant virus, rCDV-RV-G, expressing a modified (R333Q) rabies virus glycoprotein (RV-G) of RV Flury strain LEP. RV-G expression by the recombinant viruses was confirmed. Furthermore, G was proved to be incorporated into the surface of CDV particles. While replication of the recombinant virus was slightly reduced compared with the parental CDV, it stably expressed the RV-G over ten serial passages. Inoculation of mice induced specific neutralizing antibodies against both RV-G and CDV. Therefore, the rCDV-RV-G has the potential as a vaccine that may be used to control rabies virus infection in dogs and other animals. PMID:25764477

  20. High level protein expression in mammalian cells using a safe viral vector: modified vaccinia virus Ankara.

    PubMed

    Hebben, Matthias; Brants, Jan; Birck, Catherine; Samama, Jean-Pierre; Wasylyk, Bohdan; Spehner, Danièle; Pradeau, Karine; Domi, Arban; Moss, Bernard; Schultz, Patrick; Drillien, Robert

    2007-12-01

    Vaccinia virus vectors are attractive tools to direct high level protein synthesis in mammalian cells. In one of the most efficient strategies developed so far, the gene to be expressed is positioned downstream of a bacteriophage T7 promoter within the vaccinia genome and transcribed by the T7 RNA polymerase, also encoded by the vaccinia virus genome. Tight regulation of transcription and efficient translation are ensured by control elements of the Escherichia coli lactose operon and the encephalomyocarditis virus leader sequence, respectively. We have integrated such a stringently controlled expression system, previously used successfully in a standard vaccinia virus backbone, into the modified vaccinia virus Ankara strain (MVA). In this manner, proteins of interest can be produced in mammalian cells under standard laboratory conditions because of the inherent safety of the MVA strain. Using this system for expression of beta-galactosidase, about 15 mg protein could be produced from 10(8) BHK21 cells over a 24-h period, a value 4-fold higher than the amount produced from an identical expression system based on a standard vaccinia virus strain. In another application, we employed the MVA vector to produce human tubulin tyrosine ligase and demonstrate that this protein becomes a major cellular protein upon induction conditions and displays its characteristic enzymatic activity. The MVA vector should prove useful for many other applications in which mammalian cells are required for protein production. PMID:17892951

  1. Schwann cells genetically modified to express neurotrophins promote spiral ganglion neuron survival in vitro

    PubMed Central

    Pettingill, Lisa N.; Minter, Ricki L.; Shepherd, Robert K.

    2009-01-01

    The intracochlear infusion of neurotrophic factors via a mini-osmotic pump has been shown to prevent deafness-induced spiral ganglion neuron (SGN) degeneration; however, the use of pumps may increase the incidence of infection within the cochlea, making this technique unsuitable for neurotrophin administration in a clinical setting. Cell- and gene-based therapies are potential therapeutic options. This study investigated whether Schwann cells which were genetically modified to over-express the neurotrophins brain-derived neurotrophic factor (BDNF) or neurotrophin 3 (Ntf3, formerly NT-3) could support SGN survival in an in vitro model of deafness. Co-culture of either BDNF over-expressing Schwann cells or Ntf3 over-expressing Schwann cells with SGNs from early postnatal rats significantly enhanced neuronal survival in comparison to both control Schwann cells and conventional recombinant neurotrophin proteins. Transplantation of neurotrophin over-expressing Schwann cells into the cochlea may provide an alternative means of delivering neurotrophic factors to the deaf cochlea for therapeutic purposes. PMID:18304740

  2. Biodegradation of atrazine in transgenic plants expressing a modified bacterial atrazine chlorohydrolase (atzA) gene.

    PubMed

    Wang, Lin; Samac, Deborah A; Shapir, Nir; Wackett, Lawrence P; Vance, Carroll P; Olszewski, Neil E; Sadowsky, Michael J

    2005-09-01

    Atrazine is one of the most widely used herbicides in the USA. Atrazine chlorohydrolase (AtzA), the first enzyme in a six-step pathway leading to the mineralization of atrazine in Gram-negative soil bacteria, catalyses the hydrolytic dechlorination and detoxification of atrazine to hydroxyatrazine. In this study, we investigated the potential use of transgenic plants expressing atzA to take up, dechlorinate and detoxify atrazine. Alfalfa, Arabidopsis thaliana and tobacco were transformed with a modified bacterial atzA gene, p-atzA, under the control of the cassava vein mosaic virus promoter. All transgenic plant species actively expressed p-atzA and grew over a wide range of atrazine concentrations. Thin layer chromatography analyses indicated that in planta expression of p-atzA resulted in the production of hydroxyatrazine. Hydroponically grown transgenic tobacco and alfalfa dechlorinated atrazine to hydroxyatrazine in leaves, stems and roots. Moreover, p-atzA was found to be useful as a conditional-positive selection system to isolate alfalfa and Arabidopsis transformants following Agrobacterium-mediated transformation. Our work suggests that the in planta expression of p-atzA may be useful for the development of plants for the phytoremediation of atrazine-contaminated soils and soil water, and as a marker gene to select for the integration of exogenous DNA into the plant genome. PMID:17173634

  3. Genome-wide analysis of the maize (Zea may L.) CPP-like gene family and expression profiling under abiotic stress.

    PubMed

    Song, X Y; Zhang, Y Y; Wu, F C; Zhang, L

    2016-01-01

    Cysteine-rich polycomb-like (CPP) proteins are members of a small family of transcription factors, which have been identified and characterized in Arabidopsis, rice, and soybean. In this study, we investigated CPP-like genes in the maize genome. The results revealed 13 putative CPP-like genes, which were found to encode 17 distinct transcripts and were distributed unequally on 7 of 10 maize chromosomes. Analysis of phylogenetic relationships showed that Arabidopsis, rice, and maize CPP-like transcription factors can be grouped into two subfamilies. We also used real-time RT-PCR to evaluate changes in the transcript levels of ZmCPP genes in response to abiotic stresses (heat, cold, salt, and drought stresses). These findings provide an overview of the evolution of the ZmCPP gene family, which will aid in the functional characterization of CPP-like genes in maize growth and development. PMID:27525875

  4. Expression of human dystrophin following the transplantation of genetically modified mdx myoblasts.

    PubMed

    Moisset, P A; Gagnon, Y; Karpati, G; Tremblay, J P

    1998-10-01

    Transplantation of genetically modified autologous myoblasts has been proposed as a possible solution to avoid long-term use of immunosuppressive drugs. To determine the conditions to be used in this kind of approach for possible treatment of dystrophin deficiency, mdx myoblasts were infected at different multiplicities of infection (MOI or 0.01-1000) with an adenoviral vector containing a CMV promoter/enhancer driven 6.3 kb human dystrophin cDNA (minigene) and tested in vitro for transgene expression. In these cultures, dystrophin mRNA was found to be proportionate with increasing MOI. Primary myoblast cultures derived from transgenic mdx mice expressing beta-Gal under a muscle-specific promoter and showing high expression of the human mini-dystrophin transgene introduced by the adenoviral vector were grafted into anterior tibialis muscles of SCID mice. Ten and 24 days after transplantation, numerous muscle fibers expressing both human dystrophin and beta-Gal were detected throughout the mouse muscles by immunohistochemistry using an antibody specific for human dystrophin. The presence of the human mini-dystrophin mRNA was also detected by RT-PCR. These results demonstrate that three essential conditions in autologous myoblast transplantation can be achieved: (1) in vivo survival of at least some of the transduced myoblasts; (2) efficient fusion of these cells with the host muscle fibers; and (3) the high expression of the dystrophin transgene in situ. Furthermore, this article provides a novel RT-PCR-based technique to quantify the human dystrophin minigene expression in vitro and in vivo. PMID:9930339

  5. Antibiotic resistance and multidrug-resistant efflux pumps expression in lactic acid bacteria isolated from pozol, a nonalcoholic Mayan maize fermented beverage.

    PubMed

    Wacher-Rodarte, Maria Del Carmen; Trejo-Muñúzuri, Tanya Paulina; Montiel-Aguirre, Jesús Fernando; Drago-Serrano, Maria Elisa; Gutiérrez-Lucas, Raúl L; Castañeda-Sánchez, Jorge Ismael; Sainz-Espuñes, Teresita

    2016-05-01

    Pozol is a handcrafted nonalcoholic Mayan beverage produced by the spontaneous fermentation of maize dough by lactic acid bacteria. Lactic acid bacteria (LAB) are carriers of chromosomal encoded multidrug-resistant efflux pumps genes that can be transferred to pathogens and/or confer resistance to compounds released during the fermentation process causing food spoiling. The aim of this study was to evaluate the antibiotic sensibility and the transcriptional expression of ABC-type efflux pumps in LAB isolated from pozol that contributes to multidrug resistance. Analysis of LAB and Staphylococcus (S.) aureus ATCC 29213 and ATCC 6538 control strains to antibiotic susceptibility, minimal inhibitory concentration (MIC), and minimal bactericidal concentration (MBC) to ethidium bromide were based in "standard methods" whereas the ethidium bromide efflux assay was done by fluorometric assay. Transcriptional expression of efflux pumps was analyzed by RT-PCR. LAB showed antibiotic multiresistance profiles, moreover, Lactococcus (L.) lactis and Lactobacillus (L.) plantarum displayed higher ethidium bromide efflux phenotype than S. aureus control strains. Ethidium bromide resistance and ethidium bromide efflux phenotypes were unrelated with the overexpression of lmrD in L. lactics, or the underexpression of lmrA in L. plantarum and norA in S. aureus. These findings suggest that, moreover, the analyzed efflux pumps genes, other unknown redundant mechanisms may underlie the antibiotic resistance and the ethidium bromide efflux phenotype in L. lactis and L. plantarum. Phenotypic and molecular drug multiresistance assessment in LAB may improve a better selection of the fermentation starter cultures used in pozol, and to control the antibiotic resistance widespread and food spoiling for health safety. PMID:27247772

  6. Seed-specific expression of a lysine-rich protein gene, GhLRP, from cotton significantly increases the lysine content in maize seeds.

    PubMed

    Yue, Jing; Li, Cong; Zhao, Qian; Zhu, Dengyun; Yu, Jingjuan

    2014-01-01

    Maize seed storage proteins are a major source of human and livestock consumption. However, these proteins have poor nutritional value, because they are deficient in lysine and tryptophan. Much research has been done to elevate the lysine content by reducing zein content or regulating the activities of key enzymes in lysine metabolism. Using the naturally lysine-rich protein genes, sb401 and SBgLR, from potato, we previously increased the lysine and protein contents of maize seeds. Here, we examined another natural lysine-rich protein gene, GhLRP, from cotton, which increased the lysine content of transgenic maize seeds at levels varying from 16.2% to 65.0% relative to the wild-type. The total protein content was not distinctly different, except in the six transgenic lines. The lipid and starch levels did not differ substantially in Gossypium hirsutum L. lysine-rich protein (GhLRP) transgenic kernels when compared to wild-type. The agronomic characteristics of all the transgenic maize were also normal. GhLRP is a high-lysine protein candidate gene for increasing the lysine content of maize. This study provided a valuable model system for improving maize lysine content. PMID:24681583

  7. Gene flow scenarios with transgenic maize in Mexico.

    PubMed

    Serratos-Hernández, José-Antonio; Islas-Gutiérrez, Fabián; Buendía-Rodríguez, Enrique; Berthaud, Julien

    2004-01-01

    Maize diversity is widespread in Mexico and it has been stewarded by campesinos in small communities until the present. With the arrival of transgenic maize, the objective of this study is to analyze possible scenarios that could result if genetically modified maize were not regulated and openly available in Mexico. By applying a simple logistic model based on the conditions of maize production in Mexico, the dispersion of transgenic maize in different situations within fields of farmers is described. In traditional open systems of freely exchanged seed within communities it is concluded that the most likely outcome of GM maize release is the incorporation of transgenes in the genome of Mexican germplasm and possibly in that of teosinte. PMID:15901097

  8. Identification of candidate genes associated with cell wall digestibility and eQTL (expression quantitative trait loci) analysis in a Flint × Flint maize recombinant inbred line population

    PubMed Central

    Shi, Chun; Uzarowska, Anna; Ouzunova, Milena; Landbeck, Matthias; Wenzel, Gerhard; Lübberstedt, Thomas

    2007-01-01

    Background Cell-wall digestibility is the major target for improving the feeding value of forage maize. An understanding of the molecular basis for cell-wall digestibility is crucial towards breeding of highly digestible maize. Results 865 candidate ESTs for cell-wall digestibility were selected according to the analysis of expression profiles in 1) three sets of brown-midrib isogenic lines in the genetic background of inbreds 1332 (1332 and 1332 bm3), 5361 (5361 and 5361 bm3), and F2 (F2, F2 bm1, F2 bm2, and F2 bm3), 2) the contrasting extreme lines of FD (Flint × Dent, AS08 × AS 06), DD1 (Dent × Dent, AS11 × AS09), and DD2 (Dent × Dent, AS29 × AS30) mapping populations, and 3) two contrasting isogenic inbreds, AS20 and AS21. Out of those, 439 ESTs were assembled on our "Forage Quality Array", a small microarray specific for cell wall digestibility related experiments. Transcript profiles of 40 lines of a Flint × Flint population were monitored using the Forage Quality Array, which were contrasting for cell wall digestibility. Using t-tests (p < 0.01), the expression patterns of 102 ESTs were significantly different between high and low quality groups. Using interval mapping, eQTL (LOD ≥ 2.4) were detected for 20% (89 of 439) of the spotted ESTs. On average, these eQTL explained 39% of the transcription variation of the corresponding ESTs. Only 26% (23 of 89) ESTs detected a single eQTL. eQTL hotspots, containing greater than 5% of the total number of eQTL, were located in chromosomal bins 1.07, 1.12, 3.05, 8.03, and 9.04, respectively. Bin 3.05 was co-localized with a cell-wall digestibility related QTL cluster. Conclusion 102 candidate genes for cell-wall digestibility were validated by genetical genomics approach. Although the cDNA array highlights gene types (the tested gene and any close family members), trans-acting factors or metabolic bottlenecks seem to play the major role in controlling heritable variation of gene expression related to cell

  9. Vancomycin modifies the expression of the agr system in multidrug-resistant Staphylococcus aureus clinical isolates

    PubMed Central

    Cázares-Domínguez, Vicenta; Ochoa, Sara A.; Cruz-Córdova, Ariadnna; Rodea, Gerardo E.; Escalona, Gerardo; Olivares, Alma L.; Olivares-Trejo, José de Jesús; Velázquez-Guadarrama, Norma; Xicohtencatl-Cortes, Juan

    2015-01-01

    Staphylococcus aureus is an opportunistic pathogen that colonizes human hosts and causes a wide variety of diseases. Two interacting regulatory systems called agr (accessory gene regulator) and sar (staphylococcal accessory regulator) are involved in the regulation of virulence factors. The aim of this study was to evaluate the effect of vancomycin on hld and spa gene expression during the exponential and post-exponential growth phases in multidrug-resistant (MDR) S. aureus. Methods: Antibiotic susceptibility was evaluated by the standard microdilution method. The phylogenetic profile was obtained by pulsed-field gel electrophoresis (PFGE). Polymorphisms of agr and SCCmec (staphylococcal cassette chromosome mec) were analyzed by multiplex polymerase chain reaction (PCR). The expression levels of hld and spa were analyzed by reverse transcription-PCR. An enzyme-linked immunosorbent assay (ELISA) was performed to detect protein A, and biofilm formation was analyzed via crystal violet staining. Results: In total, 60.60% (20/33) of S. aureus clinical isolates were MDR. Half (10/20) of the MDR S. aureus isolates were distributed in subcluster 10, with >90% similarity among them. In the isolates of this subcluster, a high prevalence (100%) for the agrII and the cassette SCCmec II polymorphisms was found. Our data showed significant increases in hld expression during the post-exponential phase in the presence and absence of vancomycin. Significant increases in spa expression, protein A production and biofilm formation were observed during the post-exponential phase when the MDR S. aureus isolates were challenged with vancomycin. Conclusion: The polymorphism agrII, which is associated with nosocomial isolates, was the most prevalent polymorphism in MDR S. aureus. Additionally, under our study conditions, vancomycin modified hld and spa expression in these clinical isolates. Therefore, vancomycin may regulate alternative systems that jointly participate in the regulation of

  10. Disease-modifying factors in hereditary angioedema: an RNA expression-based screening

    PubMed Central

    2013-01-01

    infectious diseases as a modifying factor for HAE severity, large-scale studies would be needed to statistically associate such expression pattern to the development of this rare disease. PMID:23688356

  11. The Cry1Ab Protein Has Minor Effects on the Arbuscular Mycorrhizal Fungal Communities after Five Seasons of Continuous Bt Maize Cultivation.

    PubMed

    Zeng, Huilan; Tan, Fengxiao; Shu, Yinghua; Zhang, Yanyan; Feng, Yuanjiao; Wang, Jianwu

    2015-01-01

    The cultivation of genetically modified plants (GMP) has raised concerns regarding the plants' ecological safety. A greenhouse experiment was conducted to assess the impact of five seasons of continuous Bt (Bacillus thuringiensis) maize cultivation on the colonisation and community structure of the non-target organisms arbuscular mycorrhizal fungi (AMF) in the maize roots, bulk soils and rhizospheric soils using the terminal restriction fragment length polymorphism (T-RFLP) analysis of the 28S ribosomal DNA and sequencing methods. AMF colonisation was significantly higher in the two Bt maize lines that express Cry1Ab, 5422Bt1 (event Bt11) and 5422CBCL (MON810) than in the non-Bt isoline 5422. No significant differences were observed in the diversity of the AMF community between the roots, bulk soils and rhizospheric soils of the Bt and non-Bt maize cultivars. The AMF genus Glomus was dominant in most of the samples, as detected by DNA sequencing. A clustering analysis based on the DNA sequence data suggested that the sample types (i.e., the samples from the roots, bulk soils or rhizospheric soils) might have greater influence on the AMF community phylotypes than the maize cultivars. This study indicated that the Cry1Ab protein has minor effects on the AMF communities after five seasons of continuous Bt maize cultivation. PMID:26717324

  12. The Cry1Ab Protein Has Minor Effects on the Arbuscular Mycorrhizal Fungal Communities after Five Seasons of Continuous Bt Maize Cultivation

    PubMed Central

    Shu, Yinghua; Zhang, Yanyan; Feng, Yuanjiao; Wang, Jianwu

    2015-01-01

    The cultivation of genetically modified plants (GMP) has raised concerns regarding the plants’ ecological safety. A greenhouse experiment was conducted to assess the impact of five seasons of continuous Bt (Bacillus thuringiensis) maize cultivation on the colonisation and community structure of the non-target organisms arbuscular mycorrhizal fungi (AMF) in the maize roots, bulk soils and rhizospheric soils using the terminal restriction fragment length polymorphism (T-RFLP) analysis of the 28S ribosomal DNA and sequencing methods. AMF colonisation was significantly higher in the two Bt maize lines that express Cry1Ab, 5422Bt1 (event Bt11) and 5422CBCL (MON810) than in the non-Bt isoline 5422. No significant differences were observed in the diversity of the AMF community between the roots, bulk soils and rhizospheric soils of the Bt and non-Bt maize cultivars. The AMF genus Glomus was dominant in most of the samples, as detected by DNA sequencing. A clustering analysis based on the DNA sequence data suggested that the sample types (i.e., the samples from the roots, bulk soils or rhizospheric soils) might have greater influence on the AMF community phylotypes than the maize cultivars. This study indicated that the Cry1Ab protein has minor effects on the AMF communities after five seasons of continuous Bt maize cultivation. PMID:26717324

  13. Overexpression of an Acidic Endo-β-1,3-1,4-glucanase in Transgenic Maize Seed for Direct Utilization in Animal Feed

    PubMed Central

    Zhou, Xiaojin; Chen, Rumei; Yang, Peilong; Meng, Qingchang; Meng, Kun; Luo, Huiying; Yuan, Jianhua; Yao, Bin; Zhang, Wei

    2013-01-01

    Background Incorporation of exogenous glucanase into animal feed is common practice to remove glucan, one of the anti-nutritional factors, for efficient nutrition absorption. The acidic endo-β-1,3-1,4-glucanase (Bgl7A) from Bispora sp. MEY-1 has excellent properties and represents a potential enzyme supplement to animal feed. Methodology/Principal Findings Here we successfully developed a transgenic maize producing a high level of Bgl7AM (codon modified Bgl7A) by constructing a recombinant vector driven by the embryo-specific promoter ZM-leg1A. Southern and Western blot analysis indicated the stable integration and specific expression of the transgene in maize seeds over four generations. The β-glucanase activity of the transgenic maize seeds reached up to 779,800 U/kg, about 236-fold higher than that of non-transgenic maize. The β-glucanase derived from the transgenic maize seeds had an optimal pH of 4.0 and was stable at pH 1.0–8.0, which is in agreement with the normal environment of digestive tract. Conclusion/Significance Our study offers a transgenic maize line that could be directly used in animal feed without any glucanase production, purification and supplementation, consequently simplifying the feed enzyme processing procedure. PMID:24391711

  14. Genes and small RNA transcripts exhibit dosage-dependent expression pattern in maize copy-number alterations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Copy-number alterations are widespread in animal and plant genomes, but their immediate impact on gene expression is still unclear. In animals, copy-number alterations usually exhibit dosage effects, except for sex chromosomes that tend to be dosage compensated. In plants, genes within small duplica...

  15. Evaluation of resistance to aflatoxin contamination in kernels of maize genotypes using a GFP-expressing Aspergillus flavus strain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Evaluation of resistance or susceptibility of corn inbreds to infection by Aspergillus flavus was evaluated by a kernel screening assay. A GFP-expressing strain of A. flavus was used to accomplish this study to measure fungal spread and aflatoxin levels in real time. Among the four inbreds tested, ...

  16. Maize aluminum tolerance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize is one of the most economically important food crops grown on acid soils, where aluminum (Al) toxicity greatly limits crop yields. Considerable variation for Al tolerance exists in maize, and this variation has been exploited for many years by plant breeders to enhance maize Al tolerance. Curr...

  17. Are apparent negative effects of feeding GM MON810 maize to Atlantic salmon, Salmo salar, caused by confounding factors?

    PubMed

    Sissener, Nini H; Hemre, Gro-Ingunn; Lall, Santosh P; Sagstad, Anita; Petersen, Kjell; Williams, Jason; Rohloff, Jens; Sanden, Monica

    2011-07-01

    The present study was conducted to follow up on apparent differences in growth, relative organ sizes, cellular stress and immune function in Atlantic salmon fed feed containing GM Bacillus thuringiensis maize compared with feed containing the non-modified parental maize line. Gene expression profiling on the distal intestinal segment and liver was performed by microarray, and selected genes were followed up by quantitative PCR (qPCR). In the liver, qPCR revealed some differentially regulated genes, including up-regulation of gelsolin precursor, down-regulation of ferritin heavy subunit and a tendency towards down-regulation of metallothionein (MT)-B. This, combined with the up-regulation of anti-apoptotic protein NR13 and similar tendencies for ferritin heavy chain and MT-A and -B in the distal intestine, suggests changes in cellular stress/antioxidant status. This corresponds well with and strengthens previous findings in these fish. To exclude possible confounding factors, the maize ingredients were analysed for mycotoxins and metabolites. The GM maize contained 90 μg/kg of deoxynivalenol (DON), while the non-GM maize was below the detection limit. Differences were also observed in the metabolite profiles of the two maize varieties, some of which seemed connected to the mycotoxin level. The effects on salmon observed in the present and previous studies correspond relatively well with the effects of DON as reported in the literature for other production animals, but knowledge regarding effects and harmful dose levels in fish is scarce. Thus, it is difficult to conclude whether the observed effects are caused by the DON level or by some other aspect of the GM maize ingredient. PMID:21418706

  18. Effects of overexpression of PKAc genes on expressions of lignin-modifying enzymes by Pleurotus ostreatus.

    PubMed

    Toyokawa, Chihana; Shobu, Misaki; Tsukamoto, Rie; Okamura, Saki; Honda, Yoichi; Kamitsuji, Hisatoshi; Izumitsu, Kousuke; Suzuki, Kazumi; Irie, Toshikazu

    2016-09-01

    We studied the role of genes encoding the cAMP-dependent protein kinase A catalytic subunit (PKAc) in the ligninolytic system in Pleurotus ostreatus. The wild-type P. ostreatus strain PC9 has two PKAc-encoding genes: PKAc1 and PKAc2 (protein ID 114122 and 85056). In the current study, PKAc1 and PKAc2 were fused with a β-tubulin promoter and introduced into strain PC9 to produce the overexpression strains PKAc1-97 and PKAc2-69. These strains showed significantly higher transcription levels of isozyme genes encoding lignin-modifying enzymes than strain PC9, but the specific gene expression patterns differed between the two recombinant strains. Both recombinants showed 2.05-2.10-fold faster degradation of beechwood lignin than strain PC9. These results indicate that PKAc plays an important role in inducing the wood degradation system in P. ostreatus. PMID:26979984

  19. MaizeCyc: Metabolic networks in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeCyc is a catalog of known and predicted metabolic and transport pathways that enables plant researchers to graphically represent the metabolome of maize (Zea mays), thereby supporting integrated systems-biology analysis. Supported analyses include molecular and genetic/phenotypic profiling (e.g...

  20. Enhanced seed phytosterol accumulation through expression of a modified HMG-CoA reductase.

    PubMed

    Hey, Sandra J; Powers, Stephen J; Beale, Michael H; Hawkins, Nathaniel D; Ward, Jane L; Halford, Nigel G

    2006-03-01

    The regulation of phytosterol biosynthesis in seeds is of interest to biotechnologists because of the efficacy of dietary phytosterols in reducing blood cholesterol in humans. Mevalonate synthesis via 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase) is a key step in phytosterol biosynthesis. HMG-CoA reductase is inactivated by phosphorylation by SNF1-related protein kinase 1 (SnRK1). With the aim of increasing seed phytosterol levels, transgenic tobacco plants were produced expressing a full-length Arabidopsis (Arabidopsis thaliana) HMG-CoA reductase gene (HMG1) coding sequence, a modified HMG1 sequence encoding a protein lacking the target serine residue for phosphorylation by SnRK1, or a chimaeric sequence encoding the N-terminal domain of the Arabidopsis HMG1 enzyme fused with the catalytic domain of yeast HMG-CoA reductase, which lacks an SnRK1 target site. All three transgenes (35S-AtHMG1, 35S-AtHMG1m and 35S-AtScHMG1) were under the control of a cauliflower mosaic virus 35S RNA promoter. Levels of seed phytosterols were up to 2.44-fold higher in plants transformed with the 35S-AtHMG1m gene than in the wild-type, and were significantly higher than in plants expressing 35S-AtHMG1 or 35S-AtScHMG1. In contrast, levels of phytosterols in leaves of plants transformed with the 35S-AtHMG1m gene were unchanged, suggesting that regulation of HMG-CoA reductase by SnRK1 is an important factor in seeds but not in leaves. A total of 11 independent transgenic lines expressing 35S-AtHMG1m or 35S-AtScHMG1 also showed an altered flower phenotype, comprising a compact floret, prolonged flowering, short, pale petals, a protruding style, short stamens, late anther development, little or no pollen production, premature flower abscission and poor seed set. Because of this phenotype, the modified HMG-CoA reductase gene would have to be expressed seed specifically if it were to be engineered into a crop plant for biotechnological purposes. PMID:17177798

  1. Expression of a fungal ferulic acid esterase in alfalfa modifies cell wall digestibility

    PubMed Central

    2014-01-01

    Background Alfalfa (Medicago sativa) is an important forage crop in North America owing to its high biomass production, perennial nature and ability to fix nitrogen. Feruloyl esterase (EC 3.1.1.73) hydrolyzes ester linkages in plant cell walls and has the potential to further improve alfalfa as biomass for biofuel production. Results In this study, faeB [GenBank:AJ309807] was synthesized at GenScript and sub-cloned into a novel pEACH vector containing different signaling peptides to target type B ferulic acid esterase (FAEB) proteins to the apoplast, chloroplast, endoplasmic reticulum and vacuole. Four constructs harboring faeB were transiently expressed in Nicotiana leaves, with FAEB accumulating at high levels in all target sites, except chloroplast. Stable transformed lines of alfalfa were subsequently obtained using Agrobacterium tumefaciens (LBA4404). Out of 136 transgenic plants regenerated, 18 independent lines exhibited FAEB activity. Subsequent in vitro digestibility and Fourier transformed infrared spectroscopy (FTIR) analysis of FAEB-expressing lines showed that they possessed modified cell wall morphology and composition with a reduction in ester linkages and elevated lignin content. Consequently, they were more recalcitrant to digestion by mixed ruminal microorganisms. Interestingly, delignification by alkaline peroxide treatment followed by exposure to a commercial cellulase mixture resulted in higher glucose release from transgenic lines as compared to the control line. Conclusion Modifying cell wall crosslinking has the potential to lower recalcitrance of holocellulose, but also exhibited unintended consequences on alfalfa cell wall digestibility due to elevated lignin content. The combination of efficient delignification treatment (alkaline peroxide) and transgenic esterase activity complement each other towards efficient and effective digestion of transgenic lines. PMID:24650274

  2. Thirteen week feeding study with transgenic maize grain containing event DAS-Ø15Ø7-1 in Sprague-Dawley rats.

    PubMed

    MacKenzie, Susan A; Lamb, Ian; Schmidt, Jean; Deege, Lora; Morrisey, Michael J; Harper, Marc; Layton, Raymond J; Prochaska, Lee M; Sanders, Craig; Locke, Mary; Mattsson, Joel L; Fuentes, Angel; Delaney, Bryan

    2007-04-01

    Maize line 1507, containing event DAS-Ø15Ø7-1 (1507), is a genetically modified (GM) maize plant that expresses the cry1F gene from Bacillus thuringiensis (Bt) sbsp. aizawai and the phosphinothricin-N-acetyltransferase (pat) gene from Streptomyces viridochromogenes throughout the plant including in the grain expression of the Cry1F protein confers in planta resistance to the European corn borer (ECB; Ostrinia nubilalis Hübner: Crambidae) and other lepidopteran pests. Expression of the PAT protein confers tolerance to the herbicidal active ingredient glufosinate-ammonium. The current study evaluated the nutritional performance of rats fed diets containing 1507 maize grain in a subchronic rodent feeding study. The grains in this study, 1507, its near-isogenic control (33P66), and a non-GM commercial hybrid (33J56) contained similar amounts of proximates, amino acids, minerals, anti-nutrients, and secondary metabolites. The subchronic feeding study compared standard toxicology response variables in rats fed diets containing 1507 maize grain with those in rats fed diets containing non-GM maize grains. All diets were prepared according to the specifications of PMI Nutrition International, LLC Certified Rodent LabDiet 5002 (PMI) 5002). Diets were fed ad libitum to Sprague-Dawley rats for approximately 90 days. In-life response variables included indicators of dietary performance and weekly evaluations for clinical signs of toxicity. No toxicologically significant differences were observed in the nutritional performance variables, clinical and neurobehavioral signs, ophthalmology, clinical pathology (hematology, clinical chemistry, coagulation, and urinalysis), organ weights, and gross and microscopic pathology between any pair of treatment groups. These results demonstrate that 1507 maize grain is as safe and as nutritious as non-GM maize grain. PMID:17097206

  3. Leaf senescence is delayed in tobacco plants expressing the maize knotted1 gene under the control of a wound-inducible promoter.

    PubMed

    Luo, Keming; Deng, Wei; Xiao, Yuehua; Zheng, Xuelian; Li, Yi; Pei, Yan

    2006-11-01

    To extend the shelf life of freshly harvested vegetables and cut flowers, a maize homeobox gene Knotted1 (kn1) was placed under the control of a wound-inducible promoter win3.12 from hybrid poplar (Populus trichocarpa x P. deltoides) and introduced into tobacco plants (Nicotiana tabacum cv. Xanthi). Transgenic win3.12::kn1 plants were morphologically normal. A leaf-detachment assay demonstrated that senescence in win3.12::kn1 leaves could be delayed by at least 2 weeks compared with wild type leaves. Furthermore, all leaves of win3.12::kn1 shoots remained green and healthy 3 weeks after excision and incubation in water, while older leaves of control shoots senesced under the same conditions. Additionally, a number of adventitious roots produced at the cut ends of wild type shoots after a 3-week incubation, but much a less number of adventitious roots appeared in win3.12::kn1 shoots. The delay in senescence was also confirmed by a higher total chlorophyll (a + b) content in win3.12::kn1 leaves relative to that of the control plants. RT-PCR analysis showed that the kn1 transcript was detected in win3.12::kn1 leaves with wounding treatment, but otherwise was not observed in leaves of wild type and unwounded transgenic plants. The results presented here indicate that expression of kn1 gene driven by the wound-inducible promoter win3.12 is potentially useful to delay senescence of vegetable crops and commercial horticulture after harvest. PMID:16794826

  4. Identification of a bioactive Bowman-Birk inhibitor from an insect-resistant early maize inbred

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Breeding of maize, Zea mays, has improved insect resistance, but the genetic and biochemical basis of many of these improvements is unknown. Maize oligonucleotide microarrays were utilized to identify differentially expressed genes in leaves of three maize inbreds, parents Oh40B and W8 and progeny O...

  5. Mortality impact of MON863 transgenic maize roots on western corn rootworm larvae in the field

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mortality of western corn rootworm (Diabrotica virgifera virgifera LeConte) larvae due to feeding on MON863 transgenic maize (Zea mays L.) expressing the Cry3Bb1 protein relative to survivorship on maize with the same genetic background without the gene (isoline maize) was evaluated at three Missour...

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

    PubMed Central

    2013-01-01

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

  7. Mechanisms of disease: motoneuron disease aggravated by transgenic expression of a functionally modified AMPA receptor subunit.

    PubMed

    Kuner, Rohini; Groom, Anthony J; Müller, Gerald; Kornau, Hans-Christian; Stefovska, Vanya; Bresink, Iris; Hartmann, Bettina; Tschauner, Karsten; Waibel, Stefan; Ludolph, Albert C; Ikonomidou, Chrysanthy; Seeburg, Peter H; Turski, Lechoslaw

    2005-08-01

    To reveal whether increased Ca2+ permeability of glutamate AMPA channels triggered by the transgene for GluR-B(N) induces decline in motor functions and neurodegeneration in the spinal cord, we evaluated growth, motor coordination, and spinal reflexes in transgenic GluR-B(N) and wild-type (wt) mice. To reveal whether the transgenic GluR-B(N) expression aggravates the course of motoneuron disease in SOD1 mice, we mated heterozygous GluR-B(N) and SOD1 [C57BL6Ico-TgN(hSOD1-G93A)1Gur] mice to generate double-transgenic progeny. The phenotypic sequelae in mice carrying mutations were evaluated by monitoring growth, motor coordination, and survival. Neuronal degeneration was assessed by morphological and stereological analysis of spinal cord and brain. We found that transgenic expression in mice of GluR-B(N)-containing glutamate AMPA receptors with increased Ca2+ permeability leads to a late-onset degeneration of neurons in the spinal cord and decline of motor functions. Neuronal death progressed over the entire life span, but manifested clinically in late adulthood, resembling the course of a slow neurodegenerative disorder. Additional transgenic expression of mutated human SOD1 accelerated disease progression, aggravated severity of motor decline, and decreased survival. These observations reveal that moderate, but persistently elevated Ca2+ influx via glutamate AMPA channels causes degeneration of spinal motoneurons and motor decline over the span of life. These features resemble the course of sporadic amyotrophic lateral sclerosis (ALS) in humans and suggest that modified function of glutamate AMPA channels may be causally linked to pathogenesis of ALS. PMID:16179532

  8. Modified Citrus Pectin Reduces Galectin-3 Expression and Disease Severity in Experimental Acute Kidney Injury

    PubMed Central

    Kolatsi-Joannou, Maria; Price, Karen L.; Winyard, Paul J.; Long, David A.

    2011-01-01

    Galectin-3 is a β-galactoside binding lectin with roles in diverse processes including proliferation, apoptosis, inflammation and fibrosis which are dependent on different domains of the molecule and subcellular distribution. Although galectin-3 is known to be upregulated in acute kidney injury, the relative importance of its different domains and functions are poorly understood in the underlying pathogenesis. Therefore we experimentally modulated galectin-3 in folic acid (FA)-induced acute kidney injury utilising modified citrus pectin (MCP), a derivative of pectin which can bind to the galectin-3 carbohydrate recognition domain thereby predominantly antagonising functions linked to this role. Mice were pre-treated with normal or 1% MCP-supplemented drinking water one week before FA injection. During the initial injury phase, all FA-treated mice lost weight whilst their kidneys enlarged secondary to the renal insult; these gross changes were significantly lessened in the MCP group but this was not associated with significant changes in galectin-3 expression. At a histological level, MCP clearly reduced renal cell proliferation but did not affect apoptosis. Later, during the recovery phase at two weeks, MCP-treated mice demonstrated reduced galectin-3 in association with decreased renal fibrosis, macrophages, pro-inflammatory cytokine expression and apoptosis. Other renal galectins, galectin-1 and -9, were unchanged. Our data indicates that MCP is protective in experimental nephropathy with modulation of early proliferation and later galectin-3 expression, apoptosis and fibrosis. This raises the possibility that MCP may be a novel strategy to reduce renal injury in the long term, perhaps via carbohydrate binding-related functions of galectin-3. PMID:21494626

  9. REGISTRATION OF MAIZE GERMPLASM LINE GEMS-0067

    Technology Transfer Automated Retrieval System (TEKTRAN)

    GEMS-0067 is a partially inbred germplasm line released by Truman State University (TSU) in accordance with the Germplasm Enhancement of Maize (GEM) protocol. This line is being released for use in the development of genetically diverse, elite, amylomaize class VII parental lines possessing modifie...

  10. Inducible Resistance to Maize Streak Virus

    PubMed Central

    Shepherd, Dionne N.; Dugdale, Benjamin; Martin, Darren P.; Varsani, Arvind; Lakay, Francisco M.; Bezuidenhout, Marion E.; Monjane, Adérito L.; Thomson, Jennifer A.; Dale, James; Rybicki, Edward P.

    2014-01-01

    Maize streak virus (MSV), which causes maize streak disease (MSD), is the major viral pathogenic constraint on maize production in Africa. Type member of the Mastrevirus genus in the family Geminiviridae, MSV has a 2.7 kb, single-stranded circular DNA genome encoding a coat protein, movement protein, and the two replication-associated proteins Rep and RepA. While we have previously developed MSV-resistant transgenic maize lines constitutively expressing “dominant negative mutant” versions of the MSV Rep, the only transgenes we could use were those that caused no developmental defects during the regeneration of plants in tissue culture. A better transgene expression system would be an inducible one, where resistance-conferring transgenes are expressed only in MSV-infected cells. However, most known inducible transgene expression systems are hampered by background or “leaky” expression in the absence of the inducer. Here we describe an adaptation of the recently developed INPACT system to express MSV-derived resistance genes in cell culture. Split gene cassette constructs (SGCs) were developed containing three different transgenes in combination with three different promoter sequences. In each SGC, the transgene was split such that it would be translatable only in the presence of an infecting MSV’s replication associated protein. We used a quantitative real-time PCR assay to show that one of these SGCs (pSPLITrepIII-Rb-Ubi) inducibly inhibits MSV replication as efficiently as does a constitutively expressed transgene that has previously proven effective in protecting transgenic maize from MSV. In addition, in our cell-culture based assay pSPLITrepIII-Rb-Ubi inhibited replication of diverse MSV strains, and even, albeit to a lesser extent, of a different mastrevirus species. The application of this new technology to MSV resistance in maize could allow a better, more acceptable product. PMID:25166274

  11. Can Maize Anthocyanins Function as Resistance Molecules to Corn Earworm?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Insect herbivory of valuable crops increases the probability of fungal infection in damaged tissues. Mycotoxins produced by some fungi are harmful to livestock and humans. Anthocyanin biosynthesis in maize protects tissues from biotic and abiotic stresses. Constitutive expression of the maize B1 ...

  12. Defining the SUMO System in Maize: SUMOylation Is Up-Regulated during Endosperm Development and Rapidly Induced by Stress1[OPEN

    PubMed Central

    Augustine, Robert C.; Rytz, Thérèse C.

    2016-01-01

    In response to abiotic and biotic challenges, plants rapidly attach small ubiquitin-related modifier (SUMO) to a large collection of nuclear proteins, with studies in Arabidopsis (Arabidopsis thaliana) linking SUMOylation to stress tolerance via its modification of factors involved in chromatin and RNA dynamics. Despite this importance, little is known about SUMOylation in crop species. Here, we describe the plant SUMO system at the phylogenetic, biochemical, and transcriptional levels with a focus on maize (Zea mays). In addition to canonical SUMOs, land plants encode a loosely constrained noncanonical isoform and a variant containing a long extension upstream of the signature β-grasp fold, with cereals also expressing a novel diSUMO polypeptide bearing two SUMO β-grasp domains in tandem. Maize and other cereals also synthesize a unique SUMO-conjugating enzyme variant with more restricted expression patterns that is enzymatically active despite a distinct electrostatic surface. Maize SUMOylation primarily impacts nuclear substrates, is strongly induced by high temperatures, and displays a memory that suppresses subsequent conjugation. Both in-depth transcript and conjugate profiles in various maize organs point to tissue/cell-specific functions for SUMOylation, with potentially significant roles during embryo and endosperm maturation. Collectively, these studies define the organization of the maize SUMO system and imply important functions during seed development and stress defense. PMID:27208252

  13. The influence of fertilizer level and spore density on arbuscular mycorrhizal colonization of transgenic Bt 11 maize (Zea mays) in experimental microcosms.

    PubMed

    Cheeke, Tanya E; Pace, Brian A; Rosenstiel, Todd N; Cruzan, Mitchell B

    2011-02-01

    Crop plants genetically modified for the expression of Bacillus thuringiensis (Bt) insecticidal toxins have broad appeal for reducing insect damage in agricultural systems, yet questions remain about the impact of Bt plants on symbiotic soil organisms. Here, arbuscular mycorrhizal fungal (AMF) colonization of transgenic maize isoline Bt 11 (expressing Cry1Ab) and its non-Bt parental line (Providence) was evaluated under different fertilizer level and spore density scenarios. In a three-way factorial design, Bt 11 and non-Bt maize were inoculated with 0, 40, or 80 spores of Glomus mosseae and treated weekly with 'No' (0 g L(-1) ), 'Low' (0.23 g L(-1) ), or 'High' (1.87 g L(-1) ) levels of a complete fertilizer and grown for 60 days in a greenhouse. While no difference in AMF colonization was detected between the Bt 11 and Providence maize cultivars in the lower spore/higher fertilizer treatments, microcosm experiments demonstrated a significant reduction in AMF colonization in Bt 11 maize roots in the 80 spore treatments when fertilizer was limited. These results confirm previous work indicating an altered relationship between this Bt 11 maize isoline and AMF and demonstrate that the magnitude of this response is strongly dependent on both nutrient supply and AMF spore inoculation level. PMID:21198682

  14. Gene expression regulation in the plant growth promoting Bacillus atrophaeus UCMB-5137 stimulated by maize root exudates.

    PubMed

    Mwita, Liberata; Chan, Wai Yin; Pretorius, Theresa; Lyantagaye, Sylvester L; Lapa, Svitlana V; Avdeeva, Lilia V; Reva, Oleg N

    2016-09-15

    Despite successful use of Plant Growth Promoting Rhizobacteria (PGPR) in agriculture, little is known about specific mechanisms of gene regulation facilitating the effective communication between bacteria and plants during plant colonization. Active PGPR strain Bacillus atrophaeus UCMB-5137 was studied in this research. RNA sequencing profiles were generated in experiments where root exudate stimulations were used to mimic interactions between bacteria and plants. It was found that the gene regulation in B. atrophaeus UCMB-5137 in response to the root exudate stimuli differed from the reported gene regulation at similar conditions in B. amyloliquefaciens FZB42, which was considered as a paradigm PGPR. This difference was explained by hypersensitivity of UCMB-5137 to the root exudate stimuli impelling it to a sessile root colonization behavior through the CcpA-CodY-AbrB regulation. It was found that the transcriptional factor DegU also could play an important role in gene regulations during plant colonization. A significant stress caused by the root exudates on in vitro cultivated B. atrophaeus UCMB-5137 was noticed and discussed. Multiple cases of conflicted gene regulations showed scantiness of our knowledge on the regulatory network in Bacillus. Some of these conflicted regulations could be explained by interference of non-coding RNA (ncRNA). Search through differential expressed intergenic regions revealed 49 putative loci of ncRNA regulated by the root exudate stimuli. Possible target mRNA were predicted and a general regulatory network of B. atrophaeus UCMB-5137 genome was designed. PMID:27259668

  15. Areawide suppression of European corn borer with Bt maize reaps savings to non-Bt maize growers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transgenic maize, engineered to express insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) has become one of the most widely adopted pest management technologies in U.S. agriculture. In 2009, Bt maize was planted on more than 22.2 million ha, comprising 63% of the U.S. crop. The te...

  16. Expression in yeast of the T-urf13 protein from Texas male-sterile maize mitochondria confers sensitivity to methomyl and to Texas-cytoplasm-specific fungal toxins.

    PubMed Central

    Huang, J; Lee, S H; Lin, C; Medici, R; Hack, E; Myers, A M

    1990-01-01

    The mitochondrial gene T-urf13 from maize (Zea mays L.) with Texas male-sterile (T) cytoplasm codes for a unique 13 kd polypeptide, T-URF13, which is implicated in cytoplasmic male sterility and sensitivity to the insecticide methomyl and to host-specific fungal toxins produced by Helminthosporium maydis race T (HmT toxin) and Phyllosticta maydis (Pm toxin). A chimeric gene coding for T-URF13 fused to the mitochondrial targeting peptide from the Neurospora crassa ATP synthase subunit 9 precursor was constructed. Expression of this gene in the yeast Saccharomyces cerevisiae yielded a polypeptide that was translocated into the membrane fraction of mitochondria and processed to give a protein the same size as maize T-URF13. Methomyl, HmT toxin and Pm toxin inhibited growth of yeast cells expressing the gene fusion on medium containing glycerol as sole carbon source and stimulated respiration with NADH as substrate by isolated mitochondria from these cells. These effects were not observed in yeast cells expressing T-URF13 without a targeting peptide. The results show that T-URF13 is sufficient to confer sensitivity to methomyl and the fungal toxins in a heterologous eukaryotic system, and suggest that mitochondrial localization of T-URF13 is critical for these functions. Images Fig. 2. Fig. 3. Fig. 5. PMID:2303028

  17. Tracing transgenic maize as affected by breadmaking process and raw material for the production of a traditional maize bread, broa.

    PubMed

    Fernandes, Telmo J R; Oliveira, M Beatriz P P; Mafra, Isabel

    2013-05-01

    Broa is a maize bread highly consumed and appreciated, especially in the north and central zones of Portugal. In the manufacturing of broa, maize flour and maize semolina might be used, besides other cereals such as wheat and rye. Considering the needs for genetically modified organism (GMO) traceability in highly processed foods, the aim of this work was to assess DNA degradation, DNA amplification and GMO quantification along breadmaking process of broa. DNA degradation was noticed by its decrease of integrity after dough baking and in all parts of bread sampling. The PCR amplification results of extracted DNA from the three distinct maize breads (broa 1, 2 and 3) showed that sequences for maize invertase gene and for events MON810 and TC1507 were easily detected with strong products. Real-time PCR revealed that quantification of GMO was feasible in the three different breads and that sampling location of baked bread might have a limited influence since the average quantitative results of both events after baking were very close to the actual values in the case of broa 1 (prepared with maize semolina). In the other two maize breads subjected to the same baking treatment, the contents of MON810 maize were considerably underestimated, leading to the conclusion that heat-processing was not the responsible parameter for that distortion, but the size of particle and mechanical processing of raw maize play also a major role in GMO quantification. PMID:23265541

  18. Differential gene expression of epigenetic modifying enzymes between Tibet pig and Yorkshire in high and low altitudes.

    PubMed

    Ban, D M; Zhang, B; Wang, Z X; Zhang, H; Wu, C X

    2015-01-01

    Epigenetic modifying enzymes play important roles in the adaptation to hypoxia, although no studies have examined their expression levels in Tibet pigs. The lung is an important functional organ in hypoxia adaptation. In this study, we examined the mRNA expression level of 5 enzymes in the lung of Tibet pigs using real-time polymerase chain reaction to determine the epigenetic performance of hypoxia adaptation. We selected four groups of pig as the study object, which were Tibet pig in highland (TH), Yorkshire in highland (YH), Tibet pig in lowland (TL), Yorkshire in lowland (YL). Expression of Dnmt1 in Tibet pig was higher than that in Yorkshire (P < 0.01), although there was no significant difference between different altitudes within each breed. Expression of Dnmt3a was higher in Tibet pig than that in Yorkshire (P < 0.01), and higher in pigs from highland than that in lowland areas (P < 0.05). Expression of Hdac1 was higher in group TH than in Yorkshire (P < 0.01). Expression of Kdm3a was higher in group TH than in the rest of the groups (P < 0.01). Expression of Uhrf1 was higher in Tibet pig than in Yorkshire (P < 0.01). In conclusion, the expression levels of the 5 epigenetic modifying genes were higher in group TH than in group YH. Under conditions of oxygen deficiency, breed was the most important factor affecting DNA methylation and gene expression. PMID:25966093

  19. Comparative diversity of arthropods on Bt maize and non-Bt maize in two different cropping systems in South Africa.

    PubMed

    Truter, J; Van Hamburg, H; Van Den Berg, J

    2014-02-01

    The biodiversity of an agroecosystem is not only important for its intrinsic value but also because it influences ecological functions that are vital for crop production in sustainable agricultural systems and the surrounding environment. A concern about genetically modified (GM) crops is the potential negative impact that such crops could have on diversity and abundance of nontarget organisms, and subsequently on ecosystem functions. Therefore, it is essential to assess the potential environmental risk of the release of a GM crop and to study its effect on species assemblages within that ecosystem. Assessment of the impact of Bt maize on the environment is hampered by the lack of basic checklists of species present in maize agroecosystems. The aims of the study were to compile a checklist of arthropods that occur on maize in South Africa and to compare the diversity and abundance of arthropods and functional groups on Bt maize and non-Bt maize. Collections of arthropods were carried out during two growing seasons on Bt maize and non-Bt maize plants at two localities. Three maize fields were sampled per locality during each season. Twenty plants, each of Bt maize and non-Bt maize, were randomly selected from the fields at each site. The arthropods collected during this study were classified to morphospecies level and grouped into the following functional groups: detritivores, herbivores, predators, and parasitoids. Based on feeding strategy, herbivores and predators were further divided into sucking herbivores or predators (piercing-sucking mouthparts) and chewing herbivores or predators (chewing mouthparts). A total of 8,771 arthropod individuals, comprising 288 morphospecies and presenting 20 orders, were collected. Results from this short-term study indicated that abundance and diversity of arthropods in maize and the different functional guilds were not significantly affected by Bt maize, either in terms of diversity or abundance. PMID:24472209

  20. Distinct function of COAR and B3 domains of maize VP1 in induction of ectopic gene expression and plant developmental phenotypes in Arabidopsis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize VP1 enhancement of ABA sensitivity in roots is B3 independent. ABA and VP1 mediated suppression of auxin induced lateral root development is B3 independent. Arabidopsis transgenic system to delineate B3 dependent and COAR domain dependent regulatory functions of VP1. Analyses of ectopic ABA re...

  1. Impaired Auxin Biosynthesis in the defective endosperm18 Mutant Is Due to Mutational Loss of Expression in the ZmYuc1 Gene Encoding Endosperm-Specific YUCCA1 Protein in Maize1[C][W][OA

    PubMed Central

    Bernardi, Jamila; Lanubile, Alessandra; Li, Qin-Bao; Kumar, Dibyendu; Kladnik, Aleš; Cook, Sam D.; Ross, John J.; Marocco, Adriano; Chourey, Prem S.

    2012-01-01

    The phytohormone auxin (indole-3-acetic acid [IAA]) plays a fundamental role in vegetative and reproductive plant development. Here, we characterized a seed-specific viable maize (Zea mays) mutant, defective endosperm18 (de18) that is impaired in IAA biosynthesis. de18 endosperm showed large reductions of free IAA levels and is known to have approximately 40% less dry mass, compared with De18. Cellular analyses showed lower total cell number, smaller cell volume, and reduced level of endoreduplication in the mutant endosperm. Gene expression analyses of seed-specific tryptophan-dependent IAA pathway genes, maize Yucca1 (ZmYuc1), and two tryptophan-aminotransferase co-orthologs were performed to understand the molecular basis of the IAA deficiency in the mutant. Temporally, all three genes showed high expression coincident with high IAA levels; however, only ZmYuc1 correlated with the reduced IAA levels in the mutant throughout endosperm development. Furthermore, sequence analyses of ZmYuc1 complementary DNA and genomic clones revealed many changes specific to the mutant, including a 2-bp insertion that generated a premature stop codon and a truncated YUC1 protein of 212 amino acids, compared with the 400 amino acids in the De18. The putative, approximately 1.5-kb, Yuc1 promoter region also showed many rearrangements, including a 151-bp deletion in the mutant. Our concurrent high-density mapping and annotation studies of chromosome 10, contig 395, showed that the De18 locus was tightly linked to the gene ZmYuc1. Collectively, the data suggest that the molecular changes in the ZmYuc1 gene encoding the YUC1 protein are the causal basis of impairment in a critical step in IAA biosynthesis, essential for normal endosperm development in maize. PMID:22961134

  2. Quantitative Changes in Gimap3 and Gimap5 Expression Modify Mitochondrial DNA Segregation in Mice

    PubMed Central

    Jokinen, Riikka; Lahtinen, Taina; Marttinen, Paula; Myöhänen, Maarit; Ruotsalainen, Pilvi; Yeung, Nicolas; Shvetsova, Antonina; Kastaniotis, Alexander J.; Hiltunen, J. Kalervo; Öhman, Tiina; Nyman, Tuula A.; Weiler, Hartmut; Battersby, Brendan J.

    2015-01-01

    Mammalian mitochondrial DNA (mtDNA) is a high-copy maternally inherited genome essential for aerobic energy metabolism. Mutations in mtDNA can lead to heteroplasmy, the co-occurence of two different mtDNA variants in the same cell, which can segregate in a tissue-specific manner affecting the onset and severity of mitochondrial dysfunction. To investigate mechanisms regulating mtDNA segregation we use a heteroplasmic mouse model with two polymorphic neutral mtDNA haplotypes (NZB and BALB) that displays tissue-specific and age-dependent selection for mtDNA haplotypes. In the hematopoietic compartment there is selection for the BALB mtDNA haplotype, a phenotype that can be modified by allelic variants of Gimap3. Gimap3 is a tail-anchored member of the GTPase of the immunity-associated protein (Gimap) family of protein scaffolds important for leukocyte development and survival. Here we show how the expression of two murine Gimap3 alleles from Mus musculus domesticus and M. m. castaneus differentially affect mtDNA segregation. The castaneus allele has incorporated a uORF (upstream open reading frame) in-frame with the Gimap3 mRNA that impairs translation and imparts a negative effect on the steady-state protein abundance. We found that quantitative changes in the expression of Gimap3 and the paralogue Gimap5, which encodes a lysosomal protein, affect mtDNA segregation in the mouse hematopoietic tissues. We also show that Gimap3 localizes to the endoplasmic reticulum and not mitochondria as previously reported. Collectively these data show that the abundance of protein scaffolds on the endoplasmic reticulum and lysosomes are important to the segregation of the mitochondrial genome in the mouse hematopoietic compartment. PMID:25808953

  3. Identification and expression profile of multiple genes in channel catfish fry ten minutes after modified live Flavobacterium columnare vaccination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using PCR-select subtractive cDNA hybridization technique, 32 expressed sequence tags (ESTs) were isolated from 96 clones of a channel catfish (Ictalurus punctatus) fry subtractive library ten minutes post vaccination with a modified live Flavobacterium columnare vaccine. The transcription levels of...

  4. Identification and expression profile of multiple genes in channel catfish fry after modified live Flavobacterium columnare vaccination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using PCR-select subtractive cDNA hybridization technique, 32 expressed sequence tags (ESTs) were isolated from 96 clones of a channel catfish (Ictalurus punctatus) fry subtractive library ten minutes post vaccination with a modified live Flavobacterium columnare vaccine. The transcription levels of...

  5. Identification of over-expressed genes in modified live vaccine strain of Edwardsiella ictaluri compared to virulent strain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using PCR-select subtractive cDNA hybridization technique, 41 expressed sequence tags (ESTs) were isolated from a modified live vaccine strain (AQUAVAC-ESC, formerly RE-33) vs a virulent parent strain (EILO) of Edwardsiella ictaluri. Transcriptional levels of the 41 ESTs in the vaccine strain and th...

  6. Embryo Microinjection of Selenomethionine Reduces Hatchability and Modifies Oxidant Responsive Gene Expression in Zebrafish

    NASA Astrophysics Data System (ADS)

    Thomas, J. K.; Janz, D. M.

    2016-05-01

    In previous studies we demonstrated that exposure to selenomethionine (SeMet) causes developmental toxicities in zebrafish (Danio rerio). The objectives of this study were to establish a dose-response relationship for developmental toxicities in zebrafish after embryo microinjection of Se (8, 16 or 32 μg/g dry mass of eggs) in the form of SeMet, and to investigate potential underlying mechanism(s) of SeMet-induced developmental toxicities. A dose-dependent increase in frequencies of mortality and total deformities, and reduced hatchability were observed in zebrafish exposed to excess Se via embryo microinjection. The egg Se concentration causing 20% mortality was then used to investigate transcript abundance of proteins involved in antioxidant protection and methylation. Excess Se exposure modified gene expression of oxidant-responsive transcription factors (nuclear factor erythroid 2-related factor nrf2a and nrf2b), and enzymes involved in cellular methylation (methionine adenosyltransferase mat1a and mat2ab) in zebrafish larvae. Notably, excess Se exposure up-regulated transcript abundance of aryl hydrocarbon receptor 2 (ahr2), a signalling pathway involved in the toxicity of dioxin-related compounds. Our findings suggest that oxidative stress or modification of methylation, or a combination of these mechanisms, might be responsible for Se-induced developmental toxicities in fishes.

  7. Embryo Microinjection of Selenomethionine Reduces Hatchability and Modifies Oxidant Responsive Gene Expression in Zebrafish

    PubMed Central

    Thomas, J. K.; Janz, D. M.

    2016-01-01

    In previous studies we demonstrated that exposure to selenomethionine (SeMet) causes developmental toxicities in zebrafish (Danio rerio). The objectives of this study were to establish a dose-response relationship for developmental toxicities in zebrafish after embryo microinjection of Se (8, 16 or 32 μg/g dry mass of eggs) in the form of SeMet, and to investigate potential underlying mechanism(s) of SeMet-induced developmental toxicities. A dose-dependent increase in frequencies of mortality and total deformities, and reduced hatchability were observed in zebrafish exposed to excess Se via embryo microinjection. The egg Se concentration causing 20% mortality was then used to investigate transcript abundance of proteins involved in antioxidant protection and methylation. Excess Se exposure modified gene expression of oxidant-responsive transcription factors (nuclear factor erythroid 2-related factor nrf2a and nrf2b), and enzymes involved in cellular methylation (methionine adenosyltransferase mat1a and mat2ab) in zebrafish larvae. Notably, excess Se exposure up-regulated transcript abundance of aryl hydrocarbon receptor 2 (ahr2), a signalling pathway involved in the toxicity of dioxin-related compounds. Our findings suggest that oxidative stress or modification of methylation, or a combination of these mechanisms, might be responsible for Se-induced developmental toxicities in fishes. PMID:27210033

  8. Allergenicity assessment of genetically-modified tobacco expressing salt tolerance cbl gene.

    PubMed

    Verma, Alok Kumar; Kumar, Sandeep; Chaudhari, Bhushan P; Tuteja, Narendra; Das, Mukul; Dwivedi, Premendra D

    2014-09-01

    It is mandatory to assess the allergenic potential of genetically modified (GM) crops before their commercialization. Recently, a transgene [Calcineurin B-like (CBL) protein] has been introduced into tobacco plant to make the crop salt resistance. Therefore, it was felt necessary to assess the allergenic potential of the cbl gene product, which was introduced and expressed in Nicotiana tabacum (tobacco) plant and compared the allergenic effects with the wild-type (WT) counterpart. Bioinformatic analysis revealed that there was no significant sequence homology with known allergens. Also, no difference between the protein digestibility profiles of GM and WT tobacco was found. Rapid digestion of CBL protein (Mol Wt 35 kDa) by simulated gastric fluid (SGF) indicated reduced chances of this protein to induce allergenicity. In addition, BALB/c mice sensitized by intraperitoneal administration of WT and GM tobacco protein showed comparable levels of clinical score, specific IgE, IgG1, histamine level, similar effect on different organs as well as IgE binding proteins. These findings indicate that insertion of cbl gene in tobacco did not cause any additional allergic risk to consumer and the GM and native tobacco proteins behave similarly in both in vitro and in vivo situations even after genetic modification. PMID:25106468

  9. Shared changes in gene expression in frontal cortex of four genetically modified mouse models of depression.

    PubMed

    Hoyle, D; Juhasz, G; Aso, E; Chase, D; del Rio, J; Fabre, V; Hamon, M; Lanfumey, L; Lesch, K-P; Maldonado, R; Serra, M-A; Sharp, T; Tordera, R; Toro, C; Deakin, J F W

    2011-01-01

    This study aimed to identify whether genetic manipulation of four systems implicated in the pathogenesis of depression converge on shared molecular processes underpinning depression-like behaviour in mice. Altered 5HT function was modelled using the 5-HT transporter knock out mouse, impaired glucocorticoid receptor (GR) function using an antisense-induced knock down mouse, disrupted glutamate function using a heterozygous KO of the vesicular glutamate transporter 1 gene, and impaired cannabinoid signalling using the cannabinoid 1 receptor KO mouse. All 4 four genetically modified mice were previously shown to show exaggerated helpless behaviour compared to wild-type controls and variable degrees of anxiety and anhedonic behaviour. mRNA was extracted from frontal cortex and hybridised to Illumina microarrays. Combined contrast analysis was used to identify genes showing different patterns of up- and down-regulation across the 4 models. 1823 genes were differentially regulated. They were over-represented in gene ontology categories of metabolism, protein handling and synapse. In each model compared to wild-type mice of the same genetic background, a number of genes showed increased expression changes of >10%, other genes showed decreases in each model. Most of the genes showed mixed effects. Several previous array findings were replicated. The results point to cellular stress and changes in post-synaptic remodelling as final common mechanisms of depression and resilience. PMID:21030216

  10. Maize Brittle stalk2 encodes a COBRA-like protein expressed in early organ development but required for tissue flexibility at maturity.

    PubMed

    Sindhu, Anoop; Langewisch, Tiffany; Olek, Anna; Multani, Dilbag S; McCann, Maureen C; Vermerris, Wilfred; Carpita, Nicholas C; Johal, Gurmukh

    2007-12-01

    The maize (Zea mays) brittle stalk2 (bk2) is a recessive mutant, the aerial parts of which are easily broken. The bk2 phenotype is developmentally regulated and appears 4 weeks after planting, at about the fifth-leaf stage. Before this time, mutants are indistinguishable from wild-type siblings. Afterward, all organs of the bk2 mutants turn brittle, even the preexisting ones, and they remain brittle throughout the life of the plant. Leaf tension assays and bend tests of the internodes show that the brittle phenotype does not result from loss of tensile strength but from loss in flexibility that causes the tissues to snap instead of bend. The Bk2 gene was cloned by a combination of transposon tagging and a candidate gene approach and found to encode a COBRA-like protein similar to rice (Oryza sativa) BC1 and Arabidopsis (Arabidopsis thaliana) COBRA-LIKE4. The outer periphery of the stalk has fewer vascular bundles, and the sclerids underlying the epidermis possess thinner secondary walls. Relative cellulose content is not strictly correlated with the brittle phenotype. Cellulose content in mature zones of bk2 mature stems is lowered by 40% but is about the same as wild type in developing stems. Although relative cellulose content is lowered in leaves after the onset of the brittle phenotype, total wall mass as a proportion of dry mass is either unchanged or slightly increased, indicating a compensatory increase in noncellulosic carbohydrate mass. Fourier transform infrared spectra indicated an increase in phenolic ester content in the walls of bk2 leaves and stems. Total content of lignin is unaffected in bk2 juvenile leaves before or after appearance of the brittle phenotype, but bk2 mature and developing stems are markedly enriched in lignin compared to wild-type stems. Despite increased lignin in bk2 stems, loss of staining with phloroglucinol and ultraviolet autofluorescence is observed in vascular bundles and sclerid layers. Consistent with the infrared

  11. Strategies used for genetically modifying bacterial genome: site-directed mutagenesis, gene inactivation, and gene over-expression.

    PubMed

    Xu, Jian-zhong; Zhang, Wei-guo

    2016-02-01

    With the availability of the whole genome sequence of Escherichia coli or Corynebacterium glutamicum, strategies for directed DNA manipulation have developed rapidly. DNA manipulation plays an important role in understanding the function of genes and in constructing novel engineering bacteria according to requirement. DNA manipulation involves modifying the autologous genes and expressing the heterogenous genes. Two alternative approaches, using electroporation linear DNA or recombinant suicide plasmid, allow a wide variety of DNA manipulation. However, the over-expression of the desired gene is generally executed via plasmid-mediation. The current review summarizes the common strategies used for genetically modifying E. coli and C. glutamicum genomes, and discusses the technical problem of multi-layered DNA manipulation. Strategies for gene over-expression via integrating into genome are proposed. This review is intended to be an accessible introduction to DNA manipulation within the bacterial genome for novices and a source of the latest experimental information for experienced investigators. PMID:26834010

  12. Strategies used for genetically modifying bacterial genome: ite-directed mutagenesis, gene inactivation, and gene over-expression*

    PubMed Central

    Xu, Jian-zhong; Zhang, Wei-guo

    2016-01-01

    With the availability of the whole genome sequence of Escherichia coli or Corynebacterium glutamicum, strategies for directed DNA manipulation have developed rapidly. DNA manipulation plays an important role in understanding the function of genes and in constructing novel engineering bacteria according to requirement. DNA manipulation involves modifying the autologous genes and expressing the heterogenous genes. Two alternative approaches, using electroporation linear DNA or recombinant suicide plasmid, allow a wide variety of DNA manipulation. However, the over-expression of the desired gene is generally executed via plasmid-mediation. The current review summarizes the common strategies used for genetically modifying E. coli and C. glutamicum genomes, and discusses the technical problem of multi-layered DNA manipulation. Strategies for gene over-expression via integrating into genome are proposed. This review is intended to be an accessible introduction to DNA manipulation within the bacterial genome for novices and a source of the latest experimental information for experienced investigators. PMID:26834010

  13. Expression of PAT and NPT II proteins during the developmental stages of a genetically modified pepper developed in Korea.

    PubMed

    Kim, Hyo Jin; Lee, Si Myung; Kim, Jae Kwang; Ryu, Tae Hun; Suh, Seok Cheol; Cho, Hyun Suk

    2010-10-27

    Estimation of the protein levels introduced in a biotechnology-derived product is conducted as part of an overall safety assessment. An enzyme-linked immunosorbent assay (ELISA) was used to analyze phosphinothricin acetyltransferase (PAT) and neomycin phosphotransferase II (NPT II) protein expression in a genetically modified (GM) pepper plant developed in Korea. PAT and NPT II expression levels, based on both dry weight and fresh weight, were variable among different plant generations and plant sections from isolated genetically modified organism (GMO) fields at four developmental stages. PAT expression was highest in leaves at anthesis (11.44 μg/gdw and 2.17 μg/gfw) and lowest in roots (0.12 μg/gdw and 0.01 μg/gfw). NPT II expression was also highest in leaves at anthesis (17.31 μg/gdw and 3.41 μg/gfw) and lowest in red pepper (0.65 μg/gdw and 0.12 μg/gfw). In pollen, PAT expression was 0.59-0.62 μg/gdw, while NPT II was not detected. Both PAT and NPT II showed a general pattern of decreased expression with progression of the growing season. As expected, PAT and NPT II protein expression was not detectable in control pepper plants. PMID:20873787

  14. Increased soil phosphorus availability induced by faba bean root exudation stimulates root growth and phosphorus uptake in neighbouring maize.

    PubMed

    Zhang, Deshan; Zhang, Chaochun; Tang, Xiaoyan; Li, Haigang; Zhang, Fusuo; Rengel, Zed; Whalley, William R; Davies, William J; Shen, Jianbo

    2016-01-01

    Root growth is influenced by soil nutrients and neighbouring plants, but how these two drivers affect root interactions and regulate plant growth dynamics is poorly understood. Here, interactions between the roots of maize (Zea mays) and faba bean (Vicia faba) are characterized. Maize was grown alone (maize) or with maize (maize/maize) or faba bean (maize/faba bean) as competitors under five levels of phosphorus (P) supply, and with homogeneous or heterogeneous P distribution. Maize had longer root length and greater shoot biomass and P content when grown with faba bean than with maize. At each P supply rate, faba bean had a smaller root system than maize but greater exudation of citrate and acid phosphatase, suggesting a greater capacity to mobilize P in the rhizosphere. Heterogeneous P availability enhanced the root-length density of maize but not faba bean. Maize root proliferation in the P-rich patches was associated with increased shoot P uptake. Increased P availability by localized P application or by the presence of faba bean exudation stimulated root morphological plasticity and increased shoot growth in maize in the maize/faba bean mixture, suggesting that root interactions of neighbouring plants can be modified by increased P availability. PMID:26313736

  15. The use of directed evolution to create a stable and immunogenic recombinant BCG expressing a modified HIV-1 Gag antigen.

    PubMed

    Chapman, Rosamund; Bourn, William R; Shephard, Enid; Stutz, Helen; Douglass, Nicola; Mgwebi, Thandi; Meyers, Ann; Chin'ombe, Nyasha; Williamson, Anna-Lise

    2014-01-01

    Numerous features make Mycobacterium bovis BCG an attractive vaccine vector for HIV. It has a good safety profile, it elicits long-lasting cellular immune responses and in addition manufacturing costs are affordable. Despite these advantages it is often difficult to express viral antigens in BCG, which results in genetic instability and low immunogenicity. The aim of this study was to generate stable recombinant BCG (rBCG) that express high levels of HIV antigens, by modification of the HIV genes. A directed evolution process was applied to recombinant mycobacteria that expressed HIV-1 Gag fused to the green fluorescent protein (GFP). Higher growth rates and increased GFP expression were selected for. Through this process a modified Gag antigen was selected. Recombinant BCG that expressed the modified Gag (BCG[pWB106] and BCG[pWB206]) were more stable, produced higher levels of antigen and grew faster than those that expressed the unmodified Gag (BCG[pWB105]). The recombinant BCG that expressed the modified HIV-1 Gag induced 2 to 3 fold higher levels of Gag-specific CD4 T cells than those expressing the unmodified Gag (BCG[pWB105]). Mice primed with 10(7) CFU BCG[pWB206] and then boosted with MVA-Gag developed Gag-specific CD8 T cells with a frequency of 1343±17 SFU/10(6) splenocytes, 16 fold greater than the response induced with MVA-Gag alone. Levels of Gag-specific CD4 T cells were approximately 5 fold higher in mice primed with BCG[pWB206] and boosted with MVA-Gag than in those receiving the MVA-Gag boost alone. In addition mice vaccinated with BCG[pWB206] were protected from a surrogate vaccinia virus challenge. PMID:25061753

  16. Overexpression of a Fungal β-Mannanase from Bispora sp. MEY-1 in Maize Seeds and Enzyme Characterization

    PubMed Central

    Meng, Qingchang; Meng, Kun; Zhang, Wei; Zhou, Xiaojin; Luo, Huiying; Chen, Rumei; Yang, Peilong; Yao, Bin

    2013-01-01

    Background Mannans and heteromannans are widespread in plants cell walls and are well-known as anti-nutritional factors in animal feed. To remove these factors, it is common practice to incorporate endo-β-mannanase into feed for efficient nutrition absorption. The objective of this study was to overexpress a β-mannanase gene directly in maize, the main ingredient of animal feed, to simplify the process of feed production. Methodology/Principal Findings The man5A gene encoding an excellent β-mannanase from acidophilic Bispora sp. MEY-1 was selected for heterologous overexpression. Expression of the modified gene (man5As) was driven by the embryo-specific promoter ZM-leg1A, and the transgene was transferred to three generations by backcrossing with commercial inbred Zheng58. Its exogenous integration into the maize embryonic genome and tissue specific expression in seeds were confirmed by PCR and Southern blot and Western blot analysis, respectively. Transgenic plants at BC3 generation showed agronomic traits statistically similar to Zheng58 except for less plant height (154.0 cm vs 158.3 cm). The expression level of MAN5AS reached up to 26,860 units per kilogram of maize seeds. Compared with its counterpart produced in Pichia pastoris, seed-derived MAN5AS had higher temperature optimum (90°C), and remained more β-mannanase activities after pelleting at 80°C, 100°C or 120°C. Conclusion/Significance This study shows the genetically stable overexpression of a fungal β-mannanase in maize and offers an effective and economic approach for transgene containment in maize for direct utilization without any purification or supplementation procedures. PMID:23409143

  17. MaizeGDB, the maize model organism database

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MaizeGDB is the maize research community's database for maize genetic and genomic information. In this seminar I will outline our current endeavors including a full website redesign, the status of maize genome assembly and annotation projects, and work toward genome functional annotation. Mechanis...

  18. The human rs1050286 polymorphism alters LOX-1 expression through modifying miR-24 binding.

    PubMed

    Morini, Elena; Rizzacasa, Barbara; Pucci, Sabina; Polidoro, Chiara; Ferrè, Fabrizio; Caporossi, Daniela; Helmer Citterich, Manuela; Novelli, Giuseppe; Amati, Francesca

    2016-01-01

    The up-regulation of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), encoded by the OLR1 gene, plays a fundamental role in the pathogenesis of atherosclerosis. Moreover, OLR1 polymorphisms were associated with increased susceptibility to acute myocardial infarction (AMI) and coronary artery diseases (CAD). In these pathologies, the identification of therapeutic approaches that can inhibit or reduce LOX-1 overexpression is crucial. Predictive analysis showed a putative hsa-miR-24 binding site in the 3'UTR of OLR1, 'naturally' mutated by the presence of the rs1050286 single nucleotide polymorphism (SNP). Luciferase assays revealed that miR-24 targets OLR1 3'UTR-G, but not 3'UTR-A (P < 0.0005). The functional relevance of miR-24 in regulating the expression of OLR1 was established by overexpressing miR-24 in human cell lines heterozygous (A/G, HeLa) and homozygous (A/A, HepG2) for rs1050286 SNP. Accordingly, HeLa (A/G), but not HepG2 (A/A), showed a significant down-regulation of OLR1 both at RNA and protein level. Our results indicate that rs1050286 SNP significantly affects miR-24 binding affinity to the 3'UTR of OLR1, causing a more efficient post-transcriptional gene repression in the presence of the G allele. On this basis, we considered that OLR1 rs1050286 SNP may contribute to modify OLR1 susceptibility to AMI and CAD, so ORL1 SNPs screening could help to stratify patients risk. PMID:26542080

  19. A chimeric ecdysone receptor facilitates methoxyfenozide-dependent restoration of male fertility in ms45 maize.

    PubMed

    Unger, Erica; Cigan, A Mark; Trimnell, Mary; Xu, Rui-ji; Kendall, Tim; Roth, Brad; Albertsen, Marc

    2002-10-01

    A mutation in the maize Ms45 gene results in abortion of microspore development and a male-sterile phenotype. MS45 protein has been localized to the tapetum and maximally expressed in anthers at the early vacuolate stage of microspore development. Molecular complementation analysis determined that a transformed copy of the gene fully restored fertility to ms45 maize. In this report, using phenotypic complementation as an assay, chimeric transcriptional activators were expressed to regulate a gal:MS45 gene and test the ability of a multi-component system to restore male fertility. A high frequency of phenotypic complementation was observed when either C1-GAL4 or VP16-GAL4 activators were transcribed by promoters that expressed at a stage of anther development that precedes the early vacuolate stage of microsporogenesis. For the conditional regulation of male fertility, these transcriptional activators were modified by the addition of regions that include the ligand-binding domain from the European corn borer ecdysone receptor to generate the nuclear receptors C1-GAL4-EcR (CGEcR) and VP16-GAL4-EcR (VGEcR). These chimeric receptors were introduced with the gal:MS45 gene into ms45 maize, and in the absence of ligand, these plants were male sterile. In contrast, application of the ecdysone agonist, methoxyfenozide, to plants containing either a constitutive (Ubiquitin1) or anther-specific (maize 5126) VGEcR resulted in the restoration of fertility to ms45 plants grown in either the greenhouse or in the field. PMID:12437077

  20. δ-Opioid Receptor Activation Modified MicroRNA Expression in the Rat Kidney under Prolonged Hypoxia

    PubMed Central

    He, Xiaozhou; Yang, Yilin; Zhi, Feng; Moore, Meredith L.; Kang, Xuezhi; Chao, Dongman; Wang, Rong; Balboni, Gianfranco; Salvadori, Severo; Kim, Dong H.; Xia, Ying

    2013-01-01

    Hypoxic/ischemic injury to kidney is a frequently encountered clinical problem with limited therapeutic options. Since microRNAs are differentially involved in hypoxic/ischemic events and δ-opioid receptor (DOR) activation is known to protect against hypoxic/ischemic injury, we speculated on the involvement of DOR activation in altering the microRNA (miRNA) expression in kidney under hypoxic condition. We selected 31 miRNAs based on microarray data for quantitative PCR analysis. Among them, 14 miRNAs were significantly altered after prolonged hypoxia, DOR activation or a combination of both. We found that 1) DOR activation alters miRNA expression profiles in normoxic conditions; 2) hypoxia differentially alters miRNA expression depending on the duration of hypoxia; and 3) DOR activation can modify hypoxia-induced changes in miRNA expression. For example, 10-day hypoxia reduced the level of miR-212 by over 70%, while DOR activation could mimic such reduction even in normoxic kidney. In contrast, the same stress increased miR-29a by >100%, which was reversed following DOR activation. These first data suggest that hypoxia comprehensively modifies the miRNA profile within the kidney, which can be mimicked or modified by DOR activation. Ascertaining the targeted pathways that regulate the diverse cellular and molecular functions of miRNA may provide new insights into potential therapies for hypoxic/ischemic injury of the kidney. PMID:23596515

  1. Assessment of real-time PCR based methods for quantification of pollen-mediated gene flow from GM to conventional maize in a field study.

    PubMed

    Pla, Maria; La Paz, José-Luis; Peñas, Gisela; García, Nora; Palaudelmàs, Montserrat; Esteve, Teresa; Messeguer, Joaquima; Melé, Enric

    2006-04-01

    Maize is one of the main crops worldwide and an increasing number of genetically modified (GM) maize varieties are cultivated and commercialized in many countries in parallel to conventional crops. Given the labeling rules established e.g. in the European Union and the necessary coexistence between GM and non-GM crops, it is important to determine the extent of pollen dissemination from transgenic maize to other cultivars under field conditions. The most widely used methods for quantitative detection of GMO are based on real-time PCR, which implies the results are expressed in genome percentages (in contrast to seed or grain percentages). Our objective was to assess the accuracy of real-time PCR based assays to accurately quantify the contents of transgenic grains in non-GM fields in comparison with the real cross-fertilization rate as determined by phenotypical analysis. We performed this study in a region where both GM and conventional maize are normally cultivated and used the predominant transgenic maize Mon810 in combination with a conventional maize variety which displays the characteristic of white grains (therefore allowing cross-pollination quantification as percentage of yellow grains). Our results indicated an excellent correlation between real-time PCR results and number of cross-fertilized grains at Mon810 levels of 0.1-10%. In contrast, Mon810 percentage estimated by weight of grains produced less accurate results. Finally, we present and discuss the pattern of pollen-mediated gene flow from GM to conventional maize in an example case under field conditions. PMID:16604462

  2. Maize Genetic Resources

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter describes the resources held at the Maize Genetics Cooperation • Stock Center in detail and also provides some information about the North Central Regional Plant Introduction Station (NCRPIS) in Ames, IA, Centro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT) in Mexico, and the N...

  3. Sorghum and Maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sorghum and maize are closely related cereal grains grown throughout the world. Sorghum, a drought tolerant crop grown in semi-arid regions, is a basic food staple in many parts of the developing world, while primarily an animal feed in western countries. Maize, a major worldwide crop, is used for...

  4. MAIZE ALLELIC DIVERSITY PROJECT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Of the estimated 250-300 races of maize, only 24 races are represented in materials utilized by the Germplasm Enhancement of Maize (GEM) project, a collaborative effort between USDA-ARS and public and private sector research scientists. This is largely a result of poor performance of many races in ...

  5. Cross-Resistance between Cry1 Proteins in Fall Armyworm (Spodoptera frugiperda) May Affect the Durability of Current Pyramided Bt Maize Hybrids in Brazil

    PubMed Central

    Bernardi, Daniel; Salmeron, Eloisa; Horikoshi, Renato Jun; Bernardi, Oderlei; Dourado, Patrick Marques; Carvalho, Renato Assis; Martinelli, Samuel; Head, Graham P.; Omoto, Celso

    2015-01-01

    Genetically modified plants expressing insecticidal proteins from Bacillus thuringiensis (Bt) offer valuable options for managing insect pests with considerable environmental and economic benefits. Despite the benefits provided by Bt crops, the continuous expression of these insecticidal proteins imposes strong selection for resistance in target pest populations. Bt maize (Zea mays) hybrids have been successful in controlling fall armyworm (Spodoptera frugiperda), the main maize pest in Brazil since 2008; however, field-evolved resistance to the protein Cry1F has recently been reported. Therefore it is important to assess the possibility of cross-resistance between Cry1F and other Cry proteins expressed in Bt maize hybrids. In this study, an F2 screen followed by subsequent selection on MON 89034 maize was used to select an S. frugiperda strain (RR) able to survive on the Bt maize event MON 89034, which expresses the Cry1A.105 and Cry2Ab2 proteins. Field-collected insects from maize expressing the Cry1F protein (event TC1507) represented most of the positive (resistance allele-containing) (iso)families found. The RR strain showed high levels of resistance to Cry1F, which apparently also conferred high levels of cross resistance to Cry1A.105 and Cry1Ab, but had only low-level (10-fold) resistance to Cry2Ab2. Life history studies to investigate fitness costs associated with the resistance in RR strain revealed only small reductions in reproductive rate when compared to susceptible and heterozygous strains, but the RR strain produced 32.2% and 28.4% fewer females from each female relative to the SS and RS (pooled) strains, respectively. Consistent with the lack of significant resistance to Cry2Ab2, MON 89034 maize in combination with appropriate management practices continues to provide effective control of S. frugiperda in Brazil. Nevertheless, the occurrence of Cry1F resistance in S. frugiperda across Brazil, and the cross-resistance to Cry1Ab and Cry1A.105

  6. Cross-Resistance between Cry1 Proteins in Fall Armyworm (Spodoptera frugiperda) May Affect the Durability of Current Pyramided Bt Maize Hybrids in Brazil.

    PubMed

    Bernardi, Daniel; Salmeron, Eloisa; Horikoshi, Renato Jun; Bernardi, Oderlei; Dourado, Patrick Marques; Carvalho, Renato Assis; Martinelli, Samuel; Head, Graham P; Omoto, Celso

    2015-01-01

    Genetically modified plants expressing insecticidal proteins from Bacillus thuringiensis (Bt) offer valuable options for managing insect pests with considerable environmental and economic benefits. Despite the benefits provided by Bt crops, the continuous expression of these insecticidal proteins imposes strong selection for resistance in target pest populations. Bt maize (Zea mays) hybrids have been successful in controlling fall armyworm (Spodoptera frugiperda), the main maize pest in Brazil since 2008; however, field-evolved resistance to the protein Cry1F has recently been reported. Therefore it is important to assess the possibility of cross-resistance between Cry1F and other Cry proteins expressed in Bt maize hybrids. In this study, an F2 screen followed by subsequent selection on MON 89034 maize was used to select an S. frugiperda strain (RR) able to survive on the Bt maize event MON 89034, which expresses the Cry1A.105 and Cry2Ab2 proteins. Field-collected insects from maize expressing the Cry1F protein (event TC1507) represented most of the positive (resistance allele-containing) (iso)families found. The RR strain showed high levels of resistance to Cry1F, which apparently also conferred high levels of cross resistance to Cry1A.105 and Cry1Ab, but had only low-level (10-fold) resistance to Cry2Ab2. Life history studies to investigate fitness costs associated with the resistance in RR strain revealed only small reductions in reproductive rate when compared to susceptible and heterozygous strains, but the RR strain produced 32.2% and 28.4% fewer females from each female relative to the SS and RS (pooled) strains, respectively. Consistent with the lack of significant resistance to Cry2Ab2, MON 89034 maize in combination with appropriate management practices continues to provide effective control of S. frugiperda in Brazil. Nevertheless, the occurrence of Cry1F resistance in S. frugiperda across Brazil, and the cross-resistance to Cry1Ab and Cry1A.105

  7. Inhibition of maize histone deacetylases by HC toxin, the host-selective toxin of Cochliobolus carbonum.

    PubMed Central

    Brosch, G; Ransom, R; Lechner, T; Walton, J D; Loidl, P

    1995-01-01

    HC toxin, the host-selective toxin of the maize pathogen Cochliobolus carbonum, inhibited maize histone deacetylase (HD) at 2 microM. Chlamydocin, a related cyclic tetrapeptide, also inhibited HD activity. The toxins did not affect histone acetyltransferases. After partial purification of histone deacetylases HD1-A, HD1-B, and HD2 from germinating maize embryos, we demonstrated that the different enzymes were similarly inhibited by the toxins. Inhibitory activities were reversibly eliminated by treating toxins with 2-mercaptoethanol, presumably by modifying the carbonyl group of the epoxide-containing amino acid Aeo (2-amino-9,10-epoxy-8-oxodecanoic acid). Kinetic studies revealed that inhibition of HD was of the uncompetitive type and reversible. HC toxin, in which the epoxide group had been hydrolyzed, completely lost its inhibitory activity; when the carbonyl group of Aeo had been reduced to the corresponding alcohol, the modified toxin was less active than native toxin. In vivo treatment of embryos with HC toxin caused the accumulation of highly acetylated histone H4 subspecies and elevated acetate incorporation into H4 in susceptible-genotype embryos but not in the resistant genotype. HDs from chicken and the myxomycete Physarum polycephalum were also inhibited, indicating that the host selectivity of HC toxin is not determined by its inhibitory effect on HD. Consistent with these results, we propose a model in which HC toxin promotes the establishment of pathogenic compatibility between C. carbonum and maize by interfering with reversible histone acetylation, which is implicated in the control of fundamental cellular processes, such as chromatin structure, cell cycle progression, and gene expression. PMID:8535144

  8. Potential subchronic food safety of the stacked trait transgenic maize GH5112E-117C in Sprague-Dawley rats.

    PubMed

    Han, Shiwen; Zou, Shiying; He, Xiaoyun; Huang, Kunlun; Mei, Xiaohong

    2016-08-01

    The food safety of stacked trait genetically modified (GM) maize GH5112E-117C containing insect-resistance gene Cry1Ah and glyphosate-resistant gene G2-aroA was evaluated in comparison to non-GM Hi-II maize fed to Sprague-Dawley rats during a 90-day subchronic feeding study. Three different dietary concentrations (12.5, 25 and 50 %, w/w) of the GM maize were used or its corresponding non-GM maize. No biologically significant differences in the animals' clinical signs, body weights, food consumption, hematology, clinical chemistry, organ weights and histopathology were found between the stacked trait GM maize groups, and the non-GM maize groups. The results of the 90-day subchronic feeding study demonstrated that the stacked trait GM maize GH5112E-117C is as safe as the conventional non-GM maize Hi-II. PMID:26919987

  9. Production of a Highly Protease-Resistant Fungal α-Galactosidase in Transgenic Maize Seeds for Simplified Feed Processing.

    PubMed

    Yang, Wenxia; Zhang, Yuhong; Zhou, Xiaojin; Zhang, Wei; Xu, Xiaolu; Chen, Rumei; Meng, Qingchang; Yuan, Jianhua; Yang, Peilong; Yao, Bin

    2015-01-01

    Raffinose-family oligosaccharide (RFO) in soybeans is one of the major anti-nutritional factors for poultry and livestocks. α-Galactosidase is commonly supplemented into the animal feed to hydrolyze α-1,6-galactosidic bonds on the RFOs. To simplify the feed processing, a protease-resistant α-galactosidase encoding gene from Gibberella sp. strain F75, aga-F75, was modified by codon optimization and heterologously expressed in the embryos of transgentic maize driven by the embryo-specific promoter ZM-leg1A. The progenies were produced by backcrossing with the commercial inbred variety Zheng58. PCR, southern blot and western blot analysis confirmed the stable integration and tissue specific expression of the modified gene, aga-F75m, in seeds over four generations. The expression level of Aga-F75M reached up to 10,000 units per kilogram of maize seeds. In comparison with its counterpart produced in Pichia pastoris strain GS115, maize seed-derived Aga-F75M showed a lower temperature optimum (50 °C) and lower stability over alkaline pH range, but better thermal stability at 60 °C to 70 °C and resistance to feed pelleting inactivation (80 °C). This is the first report of producing α-galactosidase in transgenic plant. The study offers an effective and economic approach for direct utilization of α-galactosidase-producing maize without any purification or supplementation procedures in the feed processing. PMID:26053048

  10. Production of a Highly Protease-Resistant Fungal α-Galactosidase in Transgenic Maize Seeds for Simplified Feed Processing

    PubMed Central

    Zhou, Xiaojin; Zhang, Wei; Xu, Xiaolu; Chen, Rumei; Meng, Qingchang; Yuan, Jianhua; Yang, Peilong; Yao, Bin

    2015-01-01

    Raffinose-family oligosaccharide (RFO) in soybeans is one of the major anti-nutritional factors for poultry and livestocks. α-Galactosidase is commonly supplemented into the animal feed to hydrolyze α-1,6-galactosidic bonds on the RFOs. To simplify the feed processing, a protease-resistant α-galactosidase encoding gene from Gibberella sp. strain F75, aga-F75, was modified by codon optimization and heterologously expressed in the embryos of transgentic maize driven by the embryo-specific promoter ZM-leg1A. The progenies were produced by backcrossing with the commercial inbred variety Zheng58. PCR, southern blot and western blot analysis confirmed the stable integration and tissue specific expression of the modified gene, aga-F75m, in seeds over four generations. The expression level of Aga-F75M reached up to 10,000 units per kilogram of maize seeds. In comparison with its counterpart produced in Pichia pastoris strain GS115, maize seed-derived Aga-F75M showed a lower temperature optimum (50°C) and lower stability over alkaline pH range, but better thermal stability at 60°C to 70°C and resistance to feed pelleting inactivation (80°C). This is the first report of producing α-galactosidase in transgenic plant. The study offers an effective and economic approach for direct utilization of α-galactosidase-producing maize without any purification or supplementation procedures in the feed processing. PMID:26053048

  11. Development of Genetically Modified Chinese Hamster Ovary Host Cells for the Enhancement of Recombinant Tissue Plasminogen Activator Expression

    PubMed Central

    Rahimpour, Azam; Ahani, Roshanak; Najaei, Azita; Adeli, Ahmad; Barkhordari, Farzaneh; Mahboudi, Fereidoun

    2016-01-01

    Background Chinese hamster ovary (CHO) cells are the most commonly used host system for the expression of high quality recombinant proteins. However, the development of stable, high-yielding CHO cell lines is a major bottleneck in the industrial manufacturing of therapeutic proteins. Therefore, different strategies such as the generation of more efficient expression vectors and establishment of genetically engineered host cells have been employed to increase the efficiency of cell line development. In order to examine the possibility of generating improved CHO host cells, cell line engineering approaches were developed based on ceramide transfer protein (CERT), and X-box binding protein 1s (XBP1s). Methods CHO cells were transfected with CERT S132A, a mutant variant of CERT which is resistant to phosphorylation, or XBP1s expression plasmids, and then stable cell pools were generated. Transient expression of t-PA was examined in engineered cell pools in comparison to un-modified CHO host cells. Results Overexpression of CERT S132A led to the enhancement of recombinant tissue plasminogen activator (t-PA) expression in transient expression by 50%. On the other hand, it was observed that the ectopic expression of the XBP1s, did not improve the t-PA expression level. Conclusion The results obtained in this study indicate successful development of the improved CHO host cells through CERT S132A overexpression. PMID:27547109

  12. Molecular hydrogen regulates gene expression by modifying the free radical chain reaction-dependent generation of oxidized phospholipid mediators

    PubMed Central

    Iuchi, Katsuya; Imoto, Akemi; Kamimura, Naomi; Nishimaki, Kiyomi; Ichimiya, Harumi; Yokota, Takashi; Ohta, Shigeo

    2016-01-01

    We previously showed that H2 acts as a novel antioxidant to protect cells against oxidative stress. Subsequently, numerous studies have indicated the potential applications of H2 in therapeutic and preventive medicine. Moreover, H2 regulates various signal transduction pathways and the expression of many genes. However, the primary targets of H2 in the signal transduction pathways are unknown. Here, we attempted to determine how H2 regulates gene expression. In a pure chemical system, H2 gas (approximately 1%, v/v) suppressed the autoxidation of linoleic acid that proceeds by a free radical chain reaction, and pure 1-palmitoyl-2-arachidonyl-sn-glycero-3-phosphocholine (PAPC), one of the major phospholipids, was autoxidized in the presence or absence of H2. H2 modified the chemical production of the autoxidized phospholipid species in the cell-free system. Exposure of cultured cells to the H2-dependently autoxidized phospholipid species reduced Ca2+ signal transduction and mediated the expression of various genes as revealed by comprehensive microarray analysis. In the cultured cells, H2 suppressed free radical chain reaction-dependent peroxidation and recovered the increased cellular Ca2+, resulting in the regulation of Ca2+-dependent gene expression. Thus, H2 might regulate gene expression via the Ca2+ signal transduction pathway by modifying the free radical-dependent generation of oxidized phospholipid mediators. PMID:26739257

  13. Cell Type-Specific Gene Expression Analyses by RNA Sequencing Reveal Local High Nitrate-Triggered Lateral Root Initiation in Shoot-Borne Roots of Maize by Modulating Auxin-Related Cell Cycle Regulation1[OPEN

    PubMed Central

    Yu, Peng; Eggert, Kai; von Wirén, Nicolaus; Li, Chunjian; Hochholdinger, Frank

    2015-01-01

    Plants have evolved a unique plasticity of their root system architecture to flexibly exploit heterogeneously distributed mineral elements from soil. Local high concentrations of nitrate trigger lateral root initiation in adult shoot-borne roots of maize (Zea mays) by increasing the frequency of early divisions of phloem pole pericycle cells. Gene expression profiling revealed that, within 12 h of local high nitrate induction, cell cycle activators (cyclin-dependent kinases and cyclin B) were up-regulated, whereas repressors (Kip-related proteins) were down-regulated in the pericycle of shoot-borne roots. In parallel, a ubiquitin protein ligase S-Phase Kinase-Associated Protein1-cullin-F-box proteinS-Phase Kinase-Associated Protein 2B-related proteasome pathway participated in cell cycle control. The division of pericycle cells was preceded by increased levels of free indole-3-acetic acid in the stele, resulting in DR5-red fluorescent protein-marked auxin response maxima at the phloem poles. Moreover, laser-capture microdissection-based gene expression analyses indicated that, at the same time, a significant local high nitrate induction of the monocot-specific PIN-FORMED9 gene in phloem pole cells modulated auxin efflux to pericycle cells. Time-dependent gene expression analysis further indicated that local high nitrate availability resulted in PIN-FORMED9-mediated auxin efflux and subsequent cell cycle activation, which culminated in the initiation of lateral root primordia. This study provides unique insights into how adult maize roots translate information on heterogeneous nutrient availability into targeted root developmental responses. PMID:26198256

  14. [Development of transgenic maize with anti-rough dwarf virus artificial miRNA vector and their disease resistance].

    PubMed

    Xuan, Ning; Zhao, Chuanzhi; Peng, Zhenying; Chen, Gao; Bian, Fei; Lian, Mingzheng; Liu, Guoxia; Wang, Xingjun; Bi, Yuping

    2015-09-01

    Maize is one of the most important food crops. Rice black-streaked dwarf virus is a maize rough dwarf disease pathogen. The occurrence and transmission of maize rough dwarf disease brings great damage to maize production. The technology of using artificial miRNA to build antiviral plant has been proven effective in a variety of plants. However, such trials in maize have not been reported. We designed primers based on the sequence of maize zea-miR159a precursor and sequence of function protein genes and silencing RBSDV coding genes in RBSDV genome. We constructed amiRNA (artificial miRNA) gene for silencing RBSDV coding gene and gene silencing suppressor. We constructed pCAMBIA3301-121-amiRNA plant expression vector for transforming maize inbred lines Z31 by using agrobacterium mediated method. After molecular analysis of transgenic maize, homozygous lines with high miRNA expression were selected by molecular detection for a subsequent natural infection experiment. We studied the severity of maize rough dwarf disease according to a grading standard (grade 0 to 4). The experiment results showed that the disease resistance of transgenic homozygous maize with the anti-rough dwarf virus amiRNA vector was better than that of wild type. Among the transgenic maize, S6-miR159 transgenic maize had high disease resistance. It is feasible to create new maize variety by the use of artificial miRNA. PMID:26955715

  15. Effects of 90-Day Feeding of Transgenic Maize BT799 on the Reproductive System in Male Wistar Rats

    PubMed Central

    Guo, Qian-ying; He, Li-xia; Zhu, Han; Shang, Jun-li; Zhu, Ling-yan; Wang, Jun-bo; Li, Yong

    2015-01-01

    BT799 is a genetically modified (GM) maize plant that expresses the Cry1Ac gene from Bacillus thuringiensis (Bt). The Cry1Ac gene was introduced into maize line Zhen58 to encode the Bt crystal protein and thus produce insect-resistant maize BT799. Expression of Bt protein in planta confers resistance to Lepidopteran pests and corn rootworms. The present study was designed to investigate any potential effects of BT799 on the reproductive system of male rats and evaluate the nutritional value of diets containing BT799 maize grain in a 90-day subchronic rodent feeding study. Male Wistar rats were fed with diets containing BT799 maize flours or made from its near isogenic control (Zhen58) at a concentration of 84.7%, nutritionally equal to the standard AIN-93G diet. Another blank control group of male rats were treated with commercial AIN-93G diet. No significant differences in body weight, hematology and serum chemistry results were observed between rats fed with the diets containing transgenic BT799, Zhen58 and the control in this 13-week feeding study. Results of serum hormone levels, sperm parameters and relative organ/body weights indicated no treatment-related side effects on the reproductive system of male rats. In addition, no diet-related changes were found in necropsy and histopathology examinations. Based on results of the current study, we did not find any differences in the parameters tested in our study of the reproductive system of male rats between BT799 and Zhen58 or the control. PMID:26633453

  16. Effects of 90-Day Feeding of Transgenic Maize BT799 on the Reproductive System in Male Wistar Rats.

    PubMed

    Guo, Qian-ying; He, Li-xia; Zhu, Han; Shang, Jun-li; Zhu, Ling-yan; Wang, Jun-bo; Li, Yong

    2015-12-01

    BT799 is a genetically modified (GM) maize plant that expresses the Cry1Ac gene from Bacillus thuringiensis (Bt). The Cry1Ac gene was introduced into maize line Zhen58 to encode the Bt crystal protein and thus produce insect-resistant maize BT799. Expression of Bt protein in planta confers resistance to Lepidopteran pests and corn rootworms. The present study was designed to investigate any potential effects of BT799 on the reproductive system of male rats and evaluate the nutritional value of diets containing BT799 maize grain in a 90-day subchronic rodent feeding study. Male Wistar rats were fed with diets containing BT799 maize flours or made from its near isogenic control (Zhen58) at a concentration of 84.7%, nutritionally equal to the standard AIN-93G diet. Another blank control group of male rats were treated with commercial AIN-93G diet. No significant differences in body weight, hematology and serum chemistry results were observed between rats fed with the diets containing transgenic BT799, Zhen58 and the control in this 13-week feeding study. Results of serum hormone levels, sperm parameters and relative organ/body weights indicated no treatment-related side effects on the reproductive system of male rats. In addition, no diet-related changes were found in necropsy and histopathology examinations. Based on results of the current study, we did not find any differences in the parameters tested in our study of the reproductive system of male rats between BT799 and Zhen58 or the control. PMID:26633453

  17. Modified cyanobacteria

    DOEpatents

    Vermaas, Willem F J.

    2014-06-17

    Disclosed is a modified photoautotrophic bacterium comprising genes of interest that are modified in terms of their expression and/or coding region sequence, wherein modification of the genes of interest increases production of a desired product in the bacterium relative to the amount of the desired product production in a photoautotrophic bacterium that is not modified with respect to the genes of interest.

  18. The modified rice αAmy8 promoter confers high-level foreign gene expression in a novel hypoxia-inducible expression system in transgenic rice seedlings.

    PubMed

    Wu, Chung-Shen; Kuo, Wei-Tin; Chang, Chia-Yu; Kuo, Jun-Yi; Tsai, Yi-Ting; Yu, Su-May; Wu, Hsi-Ten; Chen, Peng-Wen

    2014-05-01

    Expression of α-amylase genes in rice is induced not only by sugar starvation and gibberellin (GA) but also by O2 deficiency. Promoters of two rice α-amylase genes, αAmy3 and αAmy8, have been shown to direct high-level production of recombinant proteins in rice suspension cells and germinated seeds. In the present study, we modified the cis-acting DNA elements within the sugar/GA response complex (SRC/GARC) of αAmy8 promoter. We found that addition of a G box and duplicated TA box leads to high-level expression of αAmy8 SRC/GARC and significantly enhances αAmy8 promoter activity in transformed rice cells and germinated transgenic rice seeds. We also show that these modifications have drastically increased the activity of αAmy8 promoter in rice seedlings under hypoxia. Our results reveal that the G box and duplicated TA box may play important roles in stimulating promoter activity in response to hypoxia in rice. The modified αAmy8 promoter was used to produce the recombinant human epidermal growth factor (hEGF) in rice cells and hypoxic seedlings. We found that the bioactive recombinant hEGF are stably produced and yields are up to 1.8% of total soluble protein (TSP) in transformed rice cells. The expression level of synthetic hEGF containing preferred rice codon usage comprises up to 7.8% of TSP in hypoxic transgenic seedlings. Our studies reveal that the modified αAmy8 promoter can be applicable in establishing a novel expression system for the high-level production of foreign proteins in transgenic rice cells and seedlings under hypoxia. PMID:24445591

  19. Genes identified by visible mutant phenotypes show increased bias toward one of two subgenomes of maize.

    PubMed

    Schnable, James C; Freeling, Michael

    2011-01-01

    Not all genes are created equal. Despite being supported by sequence conservation and expression data, knockout homozygotes of many genes show no visible effects, at least under laboratory conditions. We have identified a set of maize (Zea mays L.) genes which have been the subject of a disproportionate share of publications recorded at MaizeGDB. We manually anchored these "classical" maize genes to gene models in the B73 reference genome, and identified syntenic orthologs in other grass genomes. In addition to proofing the most recent version 2 maize gene models, we show that a subset of these genes, those that were identified by morphological phenotype prior to cloning, are retained at syntenic locations throughout the grasses at much higher levels than the average expressed maize gene, and are preferentially found on the maize1 subgenome even with a duplicate copy is still retained on the opposite subgenome. Maize1 is the subgenome that experienced less gene loss following the whole genome duplication in maize lineage 5-12 million years ago and genes located on this subgenome tend to be expressed at higher levels in modern maize. Links to the web based software that supported our syntenic analyses in the grasses should empower further research and support teaching involving the history of maize genetic research. Our findings exemplify the concept of "grasses as a single genetic system," where what is learned in one grass may be applied to another. PMID:21423772

  20. Expression of estrus modifies the gene expression profile in reproductive tissues on Day 19 of gestation in beef cows.

    PubMed

    Davoodi, S; Cooke, R F; Fernandes, A C C; Cappellozza, B I; Vasconcelos, J L M; Cerri, R L A

    2016-03-01

    The aim of this study was to test the effect of expression of estrus at artificial insemination (AI) on endometrium, conceptus, and CL gene expression of beef cows. Thirty-six multiparous nonlactating Nelore cows were enrolled on an estradiol- and progesterone (P4)-based timed AI protocol (AI = Day 0) and then slaughtered for the endometrium, CL, and conceptus collection on Day 19. The animals were retrospectively grouped on the basis of cows that (1) showed signs of estrus near AI (n = 19; estrus) and (2) did not show any signs of estrus (n = 17; nonestrus). Body condition score, blood sampling, and ultrasound examination were performed on Days 0, 7, and 18 of the experiment followed by messenger RNA extraction and quantitative reverse transcription polymerase chain reaction analysis of 58 target genes. Data were checked for normality and analyzed by ANOVA for repeated measures using proc GLM, MIXED, and UNIVARIATE of SAS. Only pregnant cows were included in the analyses (n = 12; nonestrus, n = 11). Estrous expression had no correlation with parameters such as body condition score, preovulatory follicle and CL diameter, P4 concentration in plasma on Days 7 and 18 after AI, and interferon-tau concentration in the uterine flushing (P > 0.15); however, a significant increase was observed in conceptus size from cows that expressed estrus (P = 0.02; 38.3 ± 2.8 vs. 28.2 ± 2.9 mm). The majority of transcripts affected by estrous expression in the endometrium belong to the immune system and adhesion molecule family (MX1, MX2, MYL12A, MMP19, CXCL10, IGLL1, and SLPI; P ≤ 0.05), as well as those related with prostaglandin synthesis (OTR and COX-2; P ≤ 0.05). Genes related to apoptosis, P4 synthesis, and prostaglandin receptor were downregulated (CYP11A, BAX, and FPr; P < 0.05) in the CL tissue of cows that expressed estrus. In addition, four genes were identified as differentially expressed in the 19-day-old conceptus from cows that expressed

  1. Genetic resources for maize cell wall biology.

    PubMed

    Penning, Bryan W; Hunter, Charles T; Tayengwa, Reuben; Eveland, Andrea L; Dugard, Christopher K; Olek, Anna T; Vermerris, Wilfred; Koch, Karen E; McCarty, Donald R; Davis, Mark F; Thomas, Steven R; McCann, Maureen C; Carpita, Nicholas C

    2009-12-01

    Grass species represent a major source of food, feed, and fiber crops and potential feedstocks for biofuel production. Most of the biomass is contributed by cell walls that are distinct in composition from all other flowering plants. Identifying cell wall-related genes and their functions underpins a fundamental understanding of growth and development in these species. Toward this goal, we are building a knowledge base of the maize (Zea mays) genes involved in cell wall biology, their expression profiles, and the phenotypic consequences of mutation. Over 750 maize genes were annotated and assembled into gene families predicted to function in cell wall biogenesis. Comparative genomics of maize, rice (Oryza sativa), and Arabidopsis (Arabidopsis thaliana) sequences reveal differences in gene family structure between grass species and a reference eudicot species. Analysis of transcript profile data for cell wall genes in developing maize ovaries revealed that expression within families differed by up to 100-fold. When transcriptional analyses of developing ovaries before pollination from Arabidopsis, rice, and maize were contrasted, distinct sets of cell wall genes were expressed in grasses. These differences in gene family structure and expression between Arabidopsis and the grasses underscore the requirement for a grass-specific genetic model for functional analyses. A UniformMu population proved to be an important resource in both forward- and reverse-genetics approaches to identify hundreds of mutants in cell wall genes. A forward screen of field-grown lines by near-infrared spectroscopic screen of mature leaves yielded several dozen lines with heritable spectroscopic phenotypes. Pyrolysis-molecular beam mass spectrometry confirmed that several nir mutants had altered carbohydrate-lignin compositions. PMID:19926802

  2. An insight into the sensitivity of maize to photoperiod changes under controlled conditions.

    PubMed

    Chen, Qiang; Zhong, Hao; Fan, Xian-Wei; Li, You-Zhi

    2015-08-01

    Response of maize to photoperiods affects adaption of this crop to environments. We characterize the phenotypes of four temperate-adapted maize foundation parents, Huangzao 4, Chang 7-2, Ye 478 and Zheng 58, and two tropically adapted maize foundation parents, M9 and Shuang M9 throughout the growth stage under three constant photoperiod regimes in a daily cycle of 24 h at 28 °C, and analysed expression of 48 photoperiod response-associated genes. Consequently, long photoperiod (LP) repressed development of the tassels of photoperiod-sensitive maize lines at V9 stage, and caused subsequent failure in flowering; failure of photoperiod-sensitive maize lines in flowering under LP was associated with lower expression of flowering-related genes; photoperiod changes could make a marked impact on spatial layout of maize inflorescence. The larger oscillation amplitude of expression of photoperiod-responsive genes occurred in LP-sensitive maize lines. In conclusion, failure in development of tassels at V9 stage under LP is an early indicator for judging photoperiod sensitivity. The adaptation of temperate-adapted maize lines to LP is due to the better coordination of expression among photoperiod-sensing genes instead of the loss of the genes. High photoperiod sensitivity of maize is due to high expression of circadian rhythm-responding genes improperly early in the light. PMID:24910171

  3. Quality protein maize germplasm characterized for amino acid profiles and endosperm opacity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quality protein maize (QPM) is improved over normal maize in grain concentrations of the essential amino acids lysine and tryptophan. QPM has a long history as tropical adapted germplasm but little effort has been made in temperate and sub-tropical adaptation and it is unknown if different modifier ...

  4. Construction of a Genetically Modified Wine Yeast Strain Expressing the Aspergillus aculeatus rhaA Gene, Encoding an α-l-Rhamnosidase of Enological Interest

    PubMed Central

    Manzanares, Paloma; Orejas, Margarita; Gil, José Vicente; de Graaff, Leo H.; Visser, Jaap; Ramón, Daniel

    2003-01-01

    The Aspergillus aculeatus rhaA gene encoding an α-l-rhamnosidase has been expressed in both laboratory and industrial wine yeast strains. Wines produced in microvinifications, conducted using a combination of the genetically modified industrial strain expressing rhaA and another strain expressing a β-glucosidase, show increased content mainly of the aromatic compound linalool. PMID:14660415

  5. Maize (Zea mays L.).

    PubMed

    Frame, Bronwyn; Warnberg, Katey; Main, Marcy; Wang, Kan

    2015-01-01

    Agrobacterium tumefaciens-mediated transformation is an effective method for introducing genes into maize. In this chapter, we describe a detailed protocol for genetic transformation of the maize genotype Hi II. Our starting plant material is immature embryos cocultivated with an Agrobacterium strain carrying a standard binary vector. In addition to step-by-step laboratory transformation procedures, we include extensive details in growing donor plants and caring for transgenic plants in the greenhouse. PMID:25300834

  6. Transcriptome analysis of embryo maturation in maize

    PubMed Central

    2013-01-01

    Background Maize is one of the most important crops in the world. With the exponentially increasing population and the need for ever increased food and feed production, an increased yield of maize grain (as well as rice, wheat and other grains) will be critical. Maize grain development is understood from the perspective of morphology, hormone responses, and storage reserve accumulation. This includes various studies on gene expression during embryo development and maturation but a global study of gene expression of the embryo has not been possible until recently. Transcriptome analysis is a powerful new tool that can be used to understand the genetic basis of embryo maturation. Results We undertook a transcriptomic analysis of normal maturing embryos at 15, 21 and 27 days after pollination (DAP), of one elite maize germplasm line that was utilized in crosses to transgenic plants. More than 19,000 genes were analyzed by this method and the challenge was to select subsets of genes that are vitally important to embryo development and maturation for the initial analysis. We describe the changes in expression for genes relating to primary metabolic pathways, DNA synthesis, late embryogenesis proteins and embryo storage proteins, shown through transcriptome analysis and confirmed levels of transcription for some genes in the transcriptome using qRT-PCR. Conclusions Numerous genes involved in embryo maturation have been identified, many of which show changes in expression level during the progression from 15 to 27 DAP. An expected array of genes involved in primary metabolism was identified. Moreover, more than 30% of transcripts represented un-annotated genes, leaving many functions to be discovered. Of particular interest are the storage protein genes, globulin-1, globulin-2 and an unidentified cupin family gene. When expressing foreign proteins in maize, the globulin-1 promoter is most often used, but this cupin family gene has much higher expression and may be a

  7. Immunological and metabolomic impacts of administration of Cry1Ab protein and MON 810 maize in mouse.

    PubMed

    Adel-Patient, Karine; Guimaraes, Valeria D; Paris, Alain; Drumare, Marie-Françoise; Ah-Leung, Sandrine; Lamourette, Patricia; Nevers, Marie-Claire; Canlet, Cécile; Molina, Jérôme; Bernard, Hervé; Créminon, Christophe; Wal, Jean-Michel

    2011-01-01

    We have investigated the immunological and metabolomic impacts of Cry1Ab administration to mice, either as a purified protein or as the Cry1Ab-expressing genetically modified (GM) MON810 maize. Humoral and cellular specific immune responses induced in BALB/cJ mice after intra-gastric (i.g.) or intra-peritoneal (i.p.) administration of purified Cry1Ab were analyzed and compared with those induced by proteins of various immunogenic and allergic potencies. Possible unintended effects of the genetic modification on the pattern of expression of maize natural allergens were studied using IgE-immunoblot and sera from maize-allergic patients. Mice were experimentally sensitized (i.g. or i.p. route) with protein extracts from GM or non-GM maize, and then anti-maize proteins and anti-Cry1Ab-induced immune responses were analyzed. In parallel, longitudinal metabolomic studies were performed on the urine of mice treated via the i.g. route. Weak immune responses were observed after i.g. administration of the different proteins. Using the i.p. route, a clear Th2 response was observed with the known allergenic proteins, whereas a mixed Th1/Th2 immune response was observed with immunogenic protein not known to be allergenic and with Cry1Ab. This then reflects protein immunogenicity in the BALB/c Th2-biased mouse strain rather than allergenicity. No difference in natural maize allergen profiles was evidenced between MON810 and its non-GM comparator. Immune responses against maize proteins were quantitatively equivalent in mice treated with MON810 vs the non-GM counterpart and no anti-Cry1Ab-specific immune response was detected in mice that received MON810. Metabolomic studies showed a slight "cultivar" effect, which represented less than 1% of the initial metabolic information. Our results confirm the immunogenicity of purified Cry1Ab without evidence of allergenic potential. Immunological and metabolomic studies revealed slight differences in mouse metabolic profiles after i

  8. Modified-Chitosan/siRNA Nanoparticles Downregulate Cellular CDX2 Expression and Cross the Gastric Mucus Barrier

    PubMed Central

    Sadio, Ana; Gustafsson, Jenny K.; Pereira, Bruno; Gomes, Carla Pereira; Hansson, Gunnar C.; David, Leonor; Pêgo, Ana Paula; Almeida, Raquel

    2014-01-01

    Development of effective non-viral vectors is of crucial importance in the implementation of RNA interference in clinical routine. The localized delivery of siRNAs to the gastrointestinal mucosa is highly desired but faces specific problems such as the stability in gastric acidity conditions and the presence of the mucus barrier. CDX2 is a transcription factor critical for intestinal differentiation being involved in the initiation and maintenance of gastrointestinal diseases. Specifically, it is the trigger of gastric intestinal metaplasia which is a precursor lesion of gastric cancer. Its expression is also altered in colorectal cancer, where it may constitute a lineage-survival oncogene. Our main objective was to develop a nanoparticle-delivery system of siRNA targeting CDX2 using modified chitosan as a vector. CDX2 expression was assessed in gastric carcinoma cell lines and nanoparticles behaviour in gastrointestinal mucus was tested in mouse explants. We show that imidazole-modified chitosan and trimethylchitosan/siRNA nanoparticles are able to downregulate CDX2 expression and overpass the gastric mucus layer but not colonic mucus. This system might constitute a potential therapeutic approach to treat CDX2-dependent gastric lesions. PMID:24925340

  9. Modified expression of peripheral blood lymphocyte muscarinic cholinergic receptors in asthmatic children.

    PubMed

    Cherubini, Emanuela; Tabbì, Luca; Scozzi, Davide; Mariotta, Salvatore; Galli, Elena; Carello, Rossella; Avitabile, Simona; Tayebati, Seyed Koshrow; Amenta, Francesco; De Vitis, Claudia; Mancini, Rita; Ricci, Alberto

    2015-07-15

    Lymphocytes possess an independent cholinergic system. We assessed the expression of muscarinic cholinergic receptors in lymphocytes from 49 asthmatic children and 10 age matched controls using Western blot. We demonstrated that CD4+ and CD8+ T cells expressed M2 and M4 muscarinic receptors which density were significantly increased in asthmatic children in comparison with controls. M2 and M4 receptor increase was strictly related with IgE and fraction of exhaled nitric oxide (FeNO) measurements and with impairment in objective measurements of airway obstruction. Increased lymphocyte muscarinic cholinergic receptor expression may concur with lung cholinergic dysfunction and with inflammatory molecular framework in asthma. PMID:26025056

  10. Enhanced antitumor effect and reduced vector dissemination with fiber-modified adenovirus vectors expressing herpes simplex virus thymidine kinase.

    PubMed

    Mizuguchi, Hiroyuki; Hayakawa, Takao

    2002-03-01

    There are at least two hurdles confronting the use of the adenovirus (Ad)-mediated herpes simplex virus thymidine kinase (HSVtk)/ganciclovir (GCV) system for the treatment of cancer. One is inefficient Ad vector-mediated gene transfer into tumor cells lacking the primary receptor, i.e., the coxsackievirus and adenovirus receptor (CAR). The other is hepatotoxicity due to unwanted vector spread into the liver, even when Ad vectors are injected intratumorally. Herein, we present an attractive strategy for overcoming such limitations based on use of a fiber-modified Ad vector containing an RGD peptide motif in the fiber knob. HSVtk-expressing Ad vectors containing mutant fiber (AdRGD-tk) or wild-type fiber (Ad-tk) were injected intratumorally into CAR-negative B16 melanoma cells inoculated into mice, after which GCV was injected intraperitoneally for 10 days. AdRGD-tk showed approximately 25 times more antitumor activity than Ad-tk. Histopathological studies suggested that liver damage in mice injected with AdRGD-tk was significantly lower than that in mice injected with Ad-tk. Intratumoral administration of luciferase-expressing Ad vectors containing the mutant fiber (AdRGD-L2) resulted in nearly 40 times more luciferase production in the tumor, but 8 times less production in the liver than the conventional Ad vectors (Ad-L2). These results indicate that combination of fiber-modified vectors and a HSVtk/GCV system is a potentially useful and safe approach for the treatment of tumors lacking CAR expression, and that fiber-modified vectors could be of great utility for gene therapy and gene transfer experiments. PMID:11896439

  11. Characterization of a sex-influenced modifier of gene expression and suppressor of position-effect variegation in Drosophila.

    PubMed

    Bhadra, U; Birchler, J A

    1996-03-20

    Modifier of white (Mow), a dominant transacting gene, has been identified through a mutagenic screen for second-site loci that alter the level of expression of the white eye color locus. Mow reduces the expression of white in most developmental stages, but enhances its expression in the pupal stage, the time at which the major contribution to the adult phenotype is made. Tests with an Alcohol dehydrogenase promoter-white reporter and a series of white truncation constructs have shown that Mow fails to affect the reporter; cis-regulatory mutations of white also show no response, suggesting a requirement for white regulatory domains for interaction with Mow. A quantitative analysis of steady-state transcript levels reveals that the white mRNA level decreases in the presence of one dose of Mow in larvae and adults, but the reduction is greater in females than males. Two other functionally related genes, brown and scarlet, also exhibit a similar sexually dimorphic alteration in expression, mediated by Mow. In the mid-pupal stage, by contrast, the level of white and brown mRNA is increased by Mow. In addition, Mow acts as a weak suppressor of position effect variegation (PEV). These observations suggest a connection between dosage modulation of gene expression and suppression of position-effect variegation. PMID:8676863

  12. Ubiquitous LEA29Y Expression Blocks T Cell Co-Stimulation but Permits Sexual Reproduction in Genetically Modified Pigs

    PubMed Central

    Bähr, Andrea; Käser, Tobias; Kemter, Elisabeth; Gerner, Wilhelm; Kurome, Mayuko; Baars, Wiebke; Herbach, Nadja; Witter, Kirsti; Wünsch, Annegret; Talker, Stephanie C.; Kessler, Barbara; Nagashima, Hiroshi; Saalmüller, Armin; Schwinzer, Reinhard; Wolf, Eckhard; Klymiuk, Nikolai

    2016-01-01

    We have successfully established and characterized a genetically modified pig line with ubiquitous expression of LEA29Y, a human CTLA4-Ig derivate. LEA29Y binds human B7.1/CD80 and B7.2/CD86 with high affinity and is thus a potent inhibitor of T cell co-stimulation via this pathway. We have characterized the expression pattern and the biological function of the transgene as well as its impact on the porcine immune system and have evaluated the potential of these transgenic pigs to propagate via assisted breeding methods. The analysis of LEA29Y expression in serum and multiple organs of CAG-LEA transgenic pigs revealed that these animals produce a biologically active transgenic product at a considerable level. They present with an immune system affected by transgene expression, but can be maintained until sexual maturity and propagated by assisted reproduction techniques. Based on previous experience with pancreatic islets expressing LEA29Y, tissues from CAG-LEA29Y transgenic pigs should be protected against rejection by human T cells. Furthermore, their immune-compromised phenotype makes CAG-LEA29Y transgenic pigs an interesting large animal model for testing human cell therapies and will provide an important tool for further clarifying the LEA29Y mode of action. PMID:27175998

  13. Effects of Drought on Gene Expression in Maize Reproductive and Leaf Meristem Tissue Revealed by RNA-Seq1[W][OA

    PubMed Central

    Kakumanu, Akshay; Ambavaram, Madana M.R.; Klumas, Curtis; Krishnan, Arjun; Batlang, Utlwang; Myers, Elijah; Grene, Ruth; Pereira, Andy

    2012-01-01

    Drought stress affects cereals especially during the reproductive stage. The maize (Zea mays) drought transcriptome was studied using RNA-Seq analysis to compare drought-treated and well-watered fertilized ovary and basal leaf meristem tissue. More drought-responsive genes responded in the ovary compared with the leaf meristem. Gene Ontology enrichment analysis revealed a massive decrease in transcript abundance of cell division and cell cycle genes in the drought-stressed ovary only. Among Gene Ontology categories related to carbohydrate metabolism, changes in starch and Suc metabolism-related genes occurred in the ovary, consistent with a decrease in starch levels, and in Suc transporter function, with no comparable changes occurring in the leaf meristem. Abscisic acid (ABA)-related processes responded positively, but only in the ovaries. Related responses suggested the operation of low glucose sensing in drought-stressed ovaries. The data are discussed in the context of the susceptibility of maize kernel to drought stress leading to embryo abortion and the relative robustness of dividing vegetative tissue taken at the same time from the same plant subjected to the same conditions. Our working hypothesis involves signaling events associated with increased ABA levels, decreased glucose levels, disruption of ABA/sugar signaling, activation of programmed cell death/senescence through repression of a phospholipase C-mediated signaling pathway, and arrest of the cell cycle in the stressed ovary at 1 d after pollination. Increased invertase levels in the stressed leaf meristem, on the other hand, resulted in that tissue maintaining hexose levels at an “unstressed” level, and at lower ABA levels, which was correlated with successful resistance to drought stress. PMID:22837360

  14. Memory consolidation and amnesia modify 5-HT6 receptors expression in rat brain: an autoradiographic study.

    PubMed

    Meneses, A; Manuel-Apolinar, L; Castillo, C; Castillo, E

    2007-03-12

    Traditionally, the search for memory circuits has been centered on examinations of amnesic and AD patients, cerebral lesions and, neuroimaging. A complementary alternative might be the use of autoradiography with radioligands. Indeed, ex vivo autoradiographic studies offer the advantage to detect functionally active receptors altered by pharmacological tools and memory formation. Hence, herein the 5-HT(6) receptor antagonist SB-399885 and the amnesic drugs scopolamine or dizocilpine were used to manipulate memory consolidation and 5-HT(6) receptors expression was determined by using [(3)H]-SB-258585. Thus, memory consolidation was impaired in scopolamine and dizocilpine treated groups relative to control vehicle but improved it in SB-399885-treated animals. SB-399885 improved memory consolidation seems to be associated with decreased 5-HT(6) receptors expression in 15 out 17 brain areas. Scopolamine or dizocilpine decreased 5-HT(6) receptors expression in nine different brain areas and increased it in CA3 hippocampus or other eight areas, respectively. In brain areas thought to be in charge of procedural memory such basal ganglia (i.e., nucleus accumbens, caudate putamen, and fundus striate) data showed that relative to control animals amnesic groups showed diminished (scopolamine) or augmented (dizocilpine) 5-HT(6) receptor expression. SB-399885 showing improved memory displayed an intermediate expression in these same brain regions. A similar intermediate expression occurs with regard to amygdala, septum, and some cortical areas in charge of explicit memory storage. However, relative to control group amnesic and SB-399885 rats in the hippocampus, region where explicit memory is formed, showed a complex 5-HT(6) receptors expression. In conclusion, these results indicate neural circuits underlying the effects of 5-HT(6) receptor antagonists in autoshaping task and offer some general clues about cognitive processes in general. PMID:17267053

  15. Patagonfibrase modifies protein expression of tissue factor and protein disulfide isomerase in rat skin.

    PubMed

    Peichoto, María Elisa; Santoro, Marcelo Larami

    2016-09-01

    Patagonfibrase is a hemorrhagic metalloproteinase isolated from the venom of the South American rear-fanged snake Philodryas patagoniensis, and is an important contributor to local lesions inflicted by this species. The tissue factor (TF)-factor VIIa complex, besides triggering the coagulation cascade, has been demonstrated to be involved in inflammatory events. Our aim was to determine whether patagonfibrase affects the expression of TF and protein disulfide isomerase (PDI), an enzyme that controls TF biological activity, at the site of patagonfibrase injection, and thus if they may play a role in hemostatic and inflammatory events induced by snake venoms. Patagonfibrase (60 μg/kg) was administered s.c. to rats, and after 3 h blood was collected to evaluate hemostasis parameters, and skin fragments close to the site of injection were taken to assess TF and PDI expression. Patagonfibrase did not alter blood cell counts, plasma fibrinogen levels, or levels of TF activity in plasma. However, by semiquantitative Western blotting, patagonfibrase increased TF expression by 2-fold, and decreased PDI expression by 3-fold in skin samples. In agreement, by immunohistochemical analyses, prominent TF expression was observed in the subcutaneous tissue. Thus, patagonfibrase affects the local expression of TF and PDI without inducing any systemic hemostatic disturbance, although that they may be involved in the local inflammatory events induced by hemorrhagic metalloproteinases. Once antivenom therapy is not totally effective to treat the local injury induced by snake venoms, modulation of the activity and expression of TF and/or PDI might become a strategy for treating snake envenomation. PMID:27390042

  16. Genotypical Differences in Aluminum Resistance of Maize Are Expressed in the Distal Part of the Transition Zone. Is Reduced Basipetal Auxin Flow Involved in Inhibition of Root Elongation by Aluminum?1

    PubMed Central

    Kollmeier, Malte; Felle, Hubert H.; Horst, Walter J.

    2000-01-01

    Short-term Al treatment (90 μm Al at pH 4.5 for 1 h) of the distal transition zone (DTZ; 1–2 mm from the root tip), which does not contribute significantly to root elongation, inhibited root elongation in the main elongation zone (EZ; 2.5–5 mm from the root tip) to the same extent as treatment of the entire maize (Zea mays) root apex. Application of Al to the EZ had no effect on root elongation. Higher genotypical resistance to Al applied to the entire root apex, and specifically to the DTZ, was expressed by less inhibition of root elongation, Al accumulation, and Al-induced callose formation, primarily in the DTZ. A characteristic pH profile along the surface of the root apex with a maximum of pH 5.3 in the DTZ was demonstrated. Al application induced a substantial flattening of the pH profile moreso in the Al-sensitive than in the Al-resistant cultivar. Application of indole-3-acetic acid to the EZ but not to the meristematic zone significantly alleviated the inhibition of root elongation induced by the application of Al to the DTZ. Basipetal transport of exogenously applied [3H]indole-3-acetic acid to the meristematic zone was significantly inhibited by Al application to the DTZ in the Al-sensitive maize cv Lixis. Our results provide evidence that the primary mechanisms of genotypical differences in Al resistance are located within the DTZ, and suggest a signaling pathway in the root apex mediating the Al signal between the DTZ and the EZ through basipetal auxin transport. PMID:10712559

  17. Genotypical differences in aluminum resistance of maize are expressed in the distal part of the transition zone. Is reduced basipetal auxin flow involved in inhibition of root elongation by aluminum?

    PubMed

    Kollmeier, M; Felle, H H; Horst, W J

    2000-03-01

    Short-term Al treatment (90 microM Al at pH 4.5 for 1 h) of the distal transition zone (DTZ; 1-2 mm from the root tip), which does not contribute significantly to root elongation, inhibited root elongation in the main elongation zone (EZ; 2.5-5 mm from the root tip) to the same extent as treatment of the entire maize (Zea mays) root apex. Application of Al to the EZ had no effect on root elongation. Higher genotypical resistance to Al applied to the entire root apex, and specifically to the DTZ, was expressed by less inhibition of root elongation, Al accumulation, and Al-induced callose formation, primarily in the DTZ. A characteristic pH profile along the surface of the root apex with a maximum of pH 5.3 in the DTZ was demonstrated. Al application induced a substantial flattening of the pH profile moreso in the Al-sensitive than in the Al-resistant cultivar. Application of indole-3-acetic acid to the EZ but not to the meristematic zone significantly alleviated the inhibition of root elongation induced by the application of Al to the DTZ. Basipetal transport of exogenously applied [(3)H]indole-3-acetic acid to the meristematic zone was significantly inhibited by Al application to the DTZ in the Al-sensitive maize cv Lixis. Our results provide evidence that the primary mechanisms of genotypical differences in Al resistance are located within the DTZ, and suggest a signaling pathway in the root apex mediating the Al signal between the DTZ and the EZ through basipetal auxin transport. PMID:10712559

  18. Mucosal Immunogenicity of Genetically Modified Lactobacillus acidophilus Expressing an HIV-1 Epitope within the Surface Layer Protein.

    PubMed

    Kajikawa, Akinobu; Zhang, Lin; LaVoy, Alora; Bumgardner, Sara; Klaenhammer, Todd R; Dean, Gregg A

    2015-01-01

    Surface layer proteins of probiotic lactobacilli are theoretically efficient epitope-displaying scaffolds for oral vaccine delivery due to their high expression levels and surface localization. In this study, we constructed genetically modified Lactobacillus acidophilus strains expressing the membrane proximal external region (MPER) from human immunodeficiency virus type 1 (HIV-1) within the context of the major S-layer protein, SlpA. Intragastric immunization of mice with the recombinants induced MPER-specific and S-layer protein-specific antibodies in serum and mucosal secretions. Moreover, analysis of systemic SlpA-specific cytokines revealed that the responses appeared to be Th1 and Th17 dominant. These findings demonstrated the potential use of the Lactobacillus S-layer protein for development of oral vaccines targeting specific peptides. PMID:26509697

  19. Evaluation of modified vaccinia virus Ankara expressing VP2 protein of infectious bursal disease virus as an immunogen in chickens.

    PubMed

    Zanetti, Flavia Adriana; Del Médico Zajac, María Paula; Taboga, Oscar Alberto; Calamante, Gabriela

    2012-06-01

    A recombinant modified vaccinia Ankara (MVA) virus expressing mature viral protein 2 (VP2) of the infectious bursal disease virus (IBDV) was constructed to develop MVA-based vaccines for poultry. We demonstrated that this recombinant virus was able to induce a specific immune response by observing the production of anti-IBDV-seroneutralizing antibodies in specific pathogen-free chickens. Besides, as the epitopes of VP2 responsible to induce IBDV-neutralizing antibodies are discontinuous, our results suggest that VP2 protein expressed from MVA-VP2 maintained the correct conformational structure. To our knowledge, this is the first report on the usefulness of MVA-based vectors for developing recombinant vaccines for poultry. PMID:22705743

  20. Mucosal Immunogenicity of Genetically Modified Lactobacillus acidophilus Expressing an HIV-1 Epitope within the Surface Layer Protein

    PubMed Central

    Kajikawa, Akinobu; Zhang, Lin; LaVoy, Alora; Bumgardner, Sara; Klaenhammer, Todd R.; Dean, Gregg A.

    2015-01-01

    Surface layer proteins of probiotic lactobacilli are theoretically efficient epitope-displaying scaffolds for oral vaccine delivery due to their high expression levels and surface localization. In this study, we constructed genetically modified Lactobacillus acidophilus strains expressing the membrane proximal external region (MPER) from human immunodeficiency virus type 1 (HIV-1) within the context of the major S-layer protein, SlpA. Intragastric immunization of mice with the recombinants induced MPER-specific and S-layer protein-specific antibodies in serum and mucosal secretions. Moreover, analysis of systemic SlpA-specific cytokines revealed that the responses appeared to be Th1 and Th17 dominant. These findings demonstrated the potential use of the Lactobacillus S-layer protein for development of oral vaccines targeting specific peptides. PMID:26509697

  1. Effect of 2'-O-methyl/thiophosphonoacetate-modified antisense oligonucleotides on huntingtin expression in patient-derived cells.

    PubMed

    Matsui, Masayuki; Threlfall, Richard N; Caruthers, Marvin H; Corey, David R

    2014-12-15

    Optimizing oligonucleotides as therapeutics will require exploring how chemistry can be used to enhance their effects inside cells. To achieve this goal it will be necessary to fully explore chemical space around the native DNA/RNA framework to define the potential of diverse chemical modifications. In this report we examine the potential of thiophosphonoacetate (thioPACE)-modified 2'-O-methyl oligoribonucleotides as inhibitors of human huntingtin (HTT) expression. Inhibition occurred, but was less than with analogous locked nucleic acid (LNA)-substituted oligomers lacking the thioPACE modification. These data suggest that thioPACE oligonucleotides have the potential to control gene expression inside cells. However, advantages relative to other modifications were not demonstrated. Additional modifications are likely to be necessary to fully explore any potential advantages of thioPACE substitutions. PMID:26865404

  2. Evaluation of modified vaccinia virus Ankara expressing VP2 protein of infectious bursal disease virus as an immunogen in chickens

    PubMed Central

    Zajac, María Paula Del Médico; Taboga, Oscar Alberto; Calamante, Gabriela

    2012-01-01

    A recombinant modified vaccinia Ankara (MVA) virus expressing mature viral protein 2 (VP2) of the infectious bursal disease virus (IBDV) was constructed to develop MVA-based vaccines for poultry. We demonstrated that this recombinant virus was able to induce a specific immune response by observing the production of anti-IBDV-seroneutralizing antibodies in specific pathogen-free chickens. Besides, as the epitopes of VP2 responsible to induce IBDV-neutralizing antibodies are discontinuous, our results suggest that VP2 protein expressed from MVA-VP2 maintained the correct conformational structure. To our knowledge, this is the first report on the usefulness of MVA-based vectors for developing recombinant vaccines for poultry. PMID:22705743

  3. Immunohistochemical expression of p53 and its clinicopathological correlation with modified Anneroth's histological grading system

    PubMed Central

    Dave, Kajal V; Chalishazar, Monali; Dave, Vishal R; Panja, Pritam; Singh, Manisha; Modi, Tapan G

    2016-01-01

    Introduction and Objectives: Oral squamous cell carcinoma (OSCC) is an epithelial neoplasm generally beginning as focal overgrowth of altered stem cells near the basement membrane, moving upward and laterally, replacing the normal epithelium. Histopathological grading has been used for many decades in an attempt to predict the clinical behavior of oral squamous cell carcinoma. In the present study, Forty biopsies were studied for histological grading and p53 expression. The p53 expression was studied in relation to clinical parameters such as age, sex of patient and site of tumors. Relation between histological grade of malignancy and p53 protein expression was analysed. All cases were classified according to Anneroth's histological malignancy grading system (1987). Materials and Methods: 40 cases of OSCC were assessed for clinical parameters, Anneroth's histological grading and immunohistochemically stained with p53 protien. Statistical Analysis: The results obtained were analyzed using Spearman's Co-relation. Observations and Results: The positive expression of p53 was found in 62% of carcinomas studied. Positivity of p53 showed correlation with histological grade of malignancy and with individual parameters like degree of keratinization, nuclear polymorphism, number of mitoses and lymphoplasmacytic infiltration while showed a negative correlation with pattern of invasion. Conclusion: Our study showed a significant correlation between parameters of tumor cell population, lymphoplasmacytic infiltration and p53 expression. A significant association between high grade of malignancy and p53 overexpression and insignificant correlation of p53 with age, sex of the patient and site of the tumor was found. PMID:27194859

  4. Dietary Nitrate Is a Modifier of Vascular Gene Expression in Old Male Mice

    PubMed Central

    Totzeck, Matthias; Deenen, René; Köhrer, Karl; Kelm, Malte; Rassaf, Tienush; Hendgen-Cotta, Ulrike B.

    2015-01-01

    Aging leads to a number of disadvantageous changes in the cardiovascular system. Deterioration of vascular homoeostasis with increase in oxidative stress, chronic low-grade inflammation, and impaired nitric oxide bioavailability results in endothelial dysfunction, increased vascular stiffness, and compromised arterial-ventricular interactions. A chronic dietary supplementation with the micronutrient nitrate has been demonstrated to improve vascular function. Healthy dietary patterns may regulate gene expression profiles. However, the mechanisms are incompletely understood. The changes that occur at the gene expression level and transcriptional profile following a nutritional modification with nitrate have not been elucidated. To determine the changes of the vascular transcriptome, we conducted gene expression microarray experiments on aortas of old mice, which were treated with dietary nitrate. Our results highlight differentially expressed genes overrepresented in gene ontology categories. Molecular interaction and reaction pathways involved in the calcium-signaling pathway and the detoxification system were identified. Our results provide novel insight to an altered gene-expression profile in old mice following nitrate supplementation. This supports the general notion of nutritional approaches to modulate age-related changes of vascular functions and its detrimental consequences. PMID:25838870

  5. Chronic Responses of Daphnia magna Under Dietary Exposure to Leaves of a Transgenic (Event MON810) Bt-Maize Hybrid and its Conventional Near-Isoline.

    PubMed

    Holderbaum, Daniel Ferreira; Cuhra, Marek; Wickson, Fern; Orth, Afonso Inácio; Nodari, Rubens Onofre; Bøhn, Thomas

    2015-01-01

    Insect resistance is the second most common trait globally in cultivated genetically modified (GM) plants. Resistance is usually obtained by introducing into the plant's genome genes from the bacterium Bacillus thuringiensis (Bt) coding for insecticidal proteins (Cry proteins or toxins) that target insect pests. The aim of this study was to examine the hypothesis that a chronic, high-dose dietary exposure to leaves of a Bt-maize hybrid (GM event MON810, expressing a transgenic or recombinant Cry1Ab toxin), exerted no adverse effects on fitness parameters of the aquatic nontarget organism Daphnia magna (water flea) when compared to an identical control diet based on leaves of the non-GM near-isoline. Cry1Ab was immunologically detected and quantified in GM maize leaf material used for Daphnia feed. A 69-kD protein near Bt's active core-toxin size and a 34-kD protein were identified. The D. magna bioassay showed a resource allocation to production of resting eggs and early fecundity in D. magna fed GM maize, with adverse effects for body size and fecundity later in life. This is the first study to examine GM-plant leaf material in the D. magna model, and provides of negative fitness effects of a MON810 maize hybrid in a nontarget model organism under chronic, high dietary exposure. Based upon these results, it is postulated that the observed transgenic proteins exert a nontarget effect in D. magna and/or unintended changes were produced in the maize genome/metabolome by the transformation process, producing a nutritional difference between GM-maize and non-GM near-isoline. PMID:26262442

  6. Chronic Responses of Daphnia magna Under Dietary Exposure to Leaves of a Transgenic (Event MON810) Bt–Maize Hybrid and its Conventional Near-Isoline

    PubMed Central

    Ferreira Holderbaum, Daniel; Cuhra, Marek; Wickson, Fern; Orth, Afonso Inácio; Nodari, Rubens Onofre; Bøhn, Thomas

    2015-01-01

    Insect resistance is the second most common trait globally in cultivated genetically modified (GM) plants. Resistance is usually obtained by introducing into the plant’s genome genes from the bacterium Bacillus thuringiensis (Bt) coding for insecticidal proteins (Cry proteins or toxins) that target insect pests. The aim of this study was to examine the hypothesis that a chronic, high-dose dietary exposure to leaves of a Bt–maize hybrid (GM event MON810, expressing a transgenic or recombinant Cry1Ab toxin), exerted no adverse effects on fitness parameters of the aquatic nontarget organism Daphnia magna (water flea) when compared to an identical control diet based on leaves of the non-GM near-isoline. Cry1Ab was immunologically detected and quantified in GM maize leaf material used for Daphnia feed. A 69-kD protein near Bt’s active core-toxin size and a 34-kD protein were identified. The D. magna bioassay showed a resource allocation to production of resting eggs and early fecundity in D. magna fed GM maize, with adverse effects for body size and fecundity later in life. This is the first study to examine GM-plant leaf material in the D. magna model, and provides of negative fitness effects of a MON810 maize hybrid in a nontarget model organism under chronic, high dietary exposure. Based upon these results, it is postulated that the observed transgenic proteins exert a nontarget effect in D. magna and/or unintended changes were produced in the maize genome/metabolome by the transformation process, producing a nutritional difference between GM-maize and non-GM near-isoline. PMID:26262442

  7. Grafting Genetically Modified Cells to the Damaged Brain: Restorative Effects of NGF Expression

    NASA Astrophysics Data System (ADS)

    Rosenberg, Michael B.; Friedmann, Theodore; Robertson, Robin C.; Tuszynski, Mark; Wolff, Jon A.; Breakefield, Xandra O.; Gage, Fred H.

    1988-12-01

    Fibroblasts were genetically modified to secrete nerve growth factor (NGF) by infection with a retroviral vector and then implanted into the brains of rats that had surgical lesions of the fimbria-fornix. The grafted cells survived and produced sufficient NGF to prevent the degeneration of cholinergic neurons that would die without treatment. In addition, the protected cholinergic cells sprouted axons that projected in the direction of the cellular source of NGF. These results indicate that a combination of gene transfer and intracerebral grafting may provide an effective treatment for some disorders of the central nervous system.

  8. Maize Photoperiod Control: Part II

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During the 2007 and 2008 seasons, the staff of the Germplasm Enhancement of Maize Project and the Maize Curatorial Project staff of the North Central Regional Plant Introduction Station experimented with various types of structures to ensure that field plantings of tropical maize germplasm were expo...

  9. The role of cis regulatory evolution in maize domestication.

    PubMed

    Lemmon, Zachary H; Bukowski, Robert; Sun, Qi; Doebley, John F

    2014-11-01

    Gene expression differences between divergent lineages caused by modification of cis regulatory elements are thought to be important in evolution. We assayed genome-wide cis and trans regulatory differences between maize and its wild progenitor, teosinte, using deep RNA sequencing in F1 hybrid and parent inbred lines for three tissue types (ear, leaf and stem). Pervasive regulatory variation was observed with approximately 70% of ∼17,000 genes showing evidence of regulatory divergence between maize and teosinte. However, many fewer genes (1,079 genes) show consistent cis differences with all sampled maize and teosinte lines. For ∼70% of these 1,079 genes, the cis differences are specific to a single tissue. The number of genes with cis regulatory differences is greatest for ear tissue, which underwent a drastic transformation in form during domestication. As expected from the domestication bottleneck, maize possesses less cis regulatory variation than teosinte with this deficit greatest for genes showing maize-teosinte cis regulatory divergence, suggesting selection on cis regulatory differences during domestication. Consistent with selection on cis regulatory elements, genes with cis effects correlated strongly with genes under positive selection during maize domestication and improvement, while genes with trans regulatory effects did not. We observed a directional bias such that genes with cis differences showed higher expression of the maize allele more often than the teosinte allele, suggesting domestication favored up-regulation of gene expression. Finally, this work documents the cis and trans regulatory changes between maize and teosinte in over 17,000 genes for three tissues. PMID:25375861

  10. A modified procedure for replica plating of mammalian cells allowing selection of clones based on gene expression.

    PubMed

    Hornsby, P J; Yang, L; Lala, D S; Cheng, C Y; Salmons, B

    1992-02-01

    The polyester cloth replica-plating technique for selection of mammalian cell clones was modified by growing cells in colonies on a flexible polytetrafluoroethylene membrane and then transferring them completely to polyester cloth (27-microns mesh), from which a replica was made by allowing cells to transfer to a cloth of smaller pore size (17-microns mesh). Using this technique, two phenotype selection methods are demonstrated here: in situ hybridization for detection of a specific mRNA and a photographic film assay for detection of luciferase expression. Cells were transfected with pSV2AL-A delta 5' in which firefly luciferase cDNA is under the control of the simian virus 40 promoter. The luciferase assay was adapted for colonies on polyester cloth; cells were permeabilized with digitonin to allow access of ATP and luciferin to the cell without disruption of colonies. Clones selected for expression or nonexpression of luciferase by the photographic film assay were positive or negative for expression after isolation from the cloth replica and subsequent growth under conventional culture conditions. The replica-plating procedure described here should be generally applicable to most mammalian cell types. The ability to produce replicas of colonies, combined with in situ hybridization or assays that can be adapted to in situ detection, provides phenotype selection for clones based on gene expression independent of growth characteristics. PMID:1616718

  11. Specificity of Ocimum basilicum geraniol synthase modified by its expression in different heterologous systems.

    PubMed

    Fischer, Marc J C; Meyer, Sophie; Claudel, Patricia; Perrin, Mireille; Ginglinger, Jean François; Gertz, Claude; Masson, Jean E; Werck-Reinhardt, Danièle; Hugueney, Philippe; Karst, Francis

    2013-01-10

    Numerous aromatic plant species produce high levels of monoterpenols, using geranyl diphosphate (GPP) as a precursor. Sweet basil (Ocimum basilicum) geraniol synthase (GES) was used to evaluate the monoterpenol profiles arising from heterologous expressions in various plant models. Grapevine (Vitis vinifera) calli were transformed using Agrobacterium tumefasciens and the plants were regenerated. Thale cress (Arabidopsis thaliana) was transformed using the floral dip method. Tobacco (Nicotiana benthamiana) leaves were agro-infiltrated for transient expression. Although, as expected, geraniol was the main product detected in the leaves, different minor products were observed in these plants (V. vinifera: citronellol and nerol; N. benthamiana: linalool and nerol; A. thaliana: none). O. basilicum GES expression was also carried out with microbial system yeasts (Saccharomyces cerevisiae) and Escherichia coli. These results suggest that the functional properties of a monoterpenol synthase depend not only on the enzyme's amino-acidic sequence, but also on the cellular background. They also suggest that some plant species or microbial expression systems could induce the simultaneous formation of several carbocations, and could thus have a natural tendency to produce a wider spectrum of monoterpenols. PMID:23108028

  12. Biodegradation of atrazine by three transgenic grasses and alfalfa expressing a modified bacterial atrazine chlorohydrolase gene

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The widespread use of atrazine and other s-triazine herbicides to control weeds in agricultural production fields has impacted surface and ground water in the United States and elsewhere. We previously reported the cloning, sequencing, and expression of six genes involved in the atrazine biodegradat...

  13. Recombinant Expression of a Modified Shrimp Anti-Lipopolysaccharide Factor Gene in Pichia pastoris GS115 and Its Characteristic Analysis.

    PubMed

    Yang, Hui; Li, Shihao; Li, Fuhua; Yu, Kuijie; Yang, Fusheng; Xiang, Jianhai

    2016-01-01

    Anti-lipopolysaccharide factors (ALFs) with a LPS-binding domain (LBD) are considered to have broad spectrum antimicrobial activities and certain antiviral properties in crustaceans. FcALF2 was one isoform of ALFs isolated from the Chinese shrimp Fenneropenaeus chinensis. Our previous study showed that a modified LBD domain (named LBDv) of FcALF2 exhibited a highly enhanced antimicrobial activity. In the present study, a modified FcALF2 gene (mFcALF2), in which the LBD was substituted by LBDv, was designed and synthesized. This gene was successfully expressed in yeast Pichia pastoris GS115 eukaryotic expression system, and the characteristics of the recombinant protein mFcALF2 were analyzed. mFcALF2 exhibited apparent antibacterial activities against Gram-negative bacteria, including Escherichia coli, Vibrio alginolyticus, Vibrio harveyi, and Vibrio parahaemolyticus, and Gram-positive bacteria, including Bacillus licheniformis and Staphylococcus epidermidis. In addition, mFcALF2 could reduce the propagation of white spot syndrome virus (WSSV) in vivo by pre-incubation with virus. The present study paves the way for developing antimicrobial drugs in aquaculture. PMID:27517939

  14. Safety assessment of genetically modified rice expressing human serum albumin from urine metabonomics and fecal bacterial profile.

    PubMed

    Qi, Xiaozhe; Chen, Siyuan; Sheng, Yao; Guo, Mingzhang; Liu, Yifei; He, Xiaoyun; Huang, Kunlun; Xu, Wentao

    2015-02-01

    The genetically modified (GM) rice expressing human serum albumin (HSA) is used for non-food purposes; however, its food safety assessment should be conducted due to the probability of accidental mixture with conventional food. In this research, Sprague Dawley rats were fed diets containing 50% (wt/wt) GM rice expressing HSA or non-GM rice for 90 days. Urine metabolites were detected by (1)H NMR to examine the changes of the metabolites in the dynamic process of metabolism. Fecal bacterial profiles were detected by denaturing gradient gel electrophoresis to reflect intestinal health. Additionally, short chain fatty acids and fecal enzymes were investigated. The results showed that compared with rats fed the non-GM rice, some significant differences were observed in rats fed with the GM rice; however, these changes were not significantly different from the control diet group. Additionally, the gut microbiota was associated with blood indexes and urine metabolites. In conclusion, the GM rice diet is as safe as the traditional daily diet. Furthermore, urine metabonomics and fecal bacterial profiles provide a non-invasive food safety assessment rat model for genetically modified crops that are used for non-food/feed purposes. Fecal bacterial profiles have the potential for predicting the change of blood indexes in future. PMID:25478734

  15. Recombinant Expression of a Modified Shrimp Anti-Lipopolysaccharide Factor Gene in Pichia pastoris GS115 and Its Characteristic Analysis

    PubMed Central

    Yang, Hui; Li, Shihao; Li, Fuhua; Yu, Kuijie; Yang, Fusheng; Xiang, Jianhai

    2016-01-01

    Anti-lipopolysaccharide factors (ALFs) with a LPS-binding domain (LBD) are considered to have broad spectrum antimicrobial activities and certain antiviral properties in crustaceans. FcALF2 was one isoform of ALFs isolated from the Chinese shrimp Fenneropenaeus chinensis. Our previous study showed that a modified LBD domain (named LBDv) of FcALF2 exhibited a highly enhanced antimicrobial activity. In the present study, a modified FcALF2 gene (mFcALF2), in which the LBD was substituted by LBDv, was designed and synthesized. This gene was successfully expressed in yeast Pichia pastoris GS115 eukaryotic expression system, and the characteristics of the recombinant protein mFcALF2 were analyzed. mFcALF2 exhibited apparent antibacterial activities against Gram-negative bacteria, including Escherichia coli, Vibrio alginolyticus, Vibrio harveyi, and Vibrio parahaemolyticus, and Gram-positive bacteria, including Bacillus licheniformis and Staphylococcus epidermidis. In addition, mFcALF2 could reduce the propagation of white spot syndrome virus (WSSV) in vivo by pre-incubation with virus. The present study paves the way for developing antimicrobial drugs in aquaculture. PMID:27517939

  16. Light Pollution Modifies the Expression of Daily Rhythms and Behavior Patterns in a Nocturnal Primate

    PubMed Central

    Le Tallec, Thomas; Perret, Martine; Théry, Marc

    2013-01-01

    Among anthropogenic pressures, light pollution altering light/dark cycles and changing the nocturnal component of the environment constitutes a threat for biodiversity. Light pollution is widely spread across the world and continuously growing. However, despite the efforts realized to describe and understand the effects of artificial lighting on fauna, few studies have documented its consequences on biological rhythms, behavioral and physiological functions in nocturnal mammals. To determine the impacts of light pollution on nocturnal mammals an experimental study was conducted on a nocturnal primate, the grey mouse lemur Microcebus murinus. Male mouse lemurs (N = 8) were exposed 14 nights to moonlight treatment and then exposed 14 nights to light pollution treatment. For both treatments, chronobiological parameters related to locomotor activity and core temperature were recorded using telemetric transmitters. In addition, at the end of each treatment, the 14th night, nocturnal and feeding behaviors were explored using an infrared camera. Finally, throughout the study, body mass and daily caloric food intake were recorded. For the first time in a nocturnal primate, light pollution was demonstrated to modify daily rhythms of locomotor activity and core temperature especially through phase delays and increases in core temperature. Moreover, nocturnal activity and feeding behaviors patterns were modified negatively. This study suggests that light pollution induces daily desynchronization of biological rhythms and could lead to seasonal desynchronization with potential deleterious consequences for animals in terms of adaptation and anticipation of environmental changes. PMID:24236115

  17. Inducible Gene Expression in Tumors Colonized by Modified Oncolytic Vaccinia Virus Strains

    PubMed Central

    Huppertz, Sascha; Zhang, Qian; Geissinger, Ulrike; Härtl, Barbara; Gentschev, Ivaylo

    2014-01-01

    ABSTRACT Exogenous gene induction of therapeutic, diagnostic, and safety mechanisms could be a considerable improvement in oncolytic virotherapy. Here, we introduced a doxycycline-inducible promoter system (comprised of a tetracycline repressor, several promoter constructs, and a tet operator sequence) into oncolytic recombinant vaccinia viruses (rVACV), which were further characterized in detail. Experiments in cell cultures as well as in tumor-bearing mice were analyzed to determine the role of the inducible-system components. To accomplish this, we took advantage of the optical reporter construct, which resulted in the production of click-beetle luciferase as well as a red fluorescent protein. The results indicated that each of the system components could be used to optimize the induction rates and had an influence on the background expression levels. Depending on the given gene to be induced in rVACV-colonized tumors of patients, we discuss the doxycycline-inducible promoter system adjustment and further optimization. IMPORTANCE Oncolytic virotherapy of cancer can greatly benefit from the expression of heterologous genes. It is reasonable that some of those heterologous gene products could have detrimental effects either on the cancer patient or on the oncolytic virus itself if they are expressed at the wrong time or if the expression levels are too high. Therefore, exogenous control of gene expression levels by administration of a nontoxic inducer will have positive effects on the safety as well as the therapeutic outcome of oncolytic virotherapy. In addition, it paves the way for the introduction of new therapeutic genes into the genome of oncolytic viruses that could not have been tested otherwise. PMID:25056902

  18. Gestational nicotine exposure modifies myelin gene expression in the brains of adolescent rats with sex differences

    PubMed Central

    Cao, J; Wang, J; Dwyer, J B; Gautier, N M; Wang, S; Leslie, F M; Li, M D

    2013-01-01

    Myelination defects in the central nervous system (CNS) are associated with various psychiatric disorders, including drug addiction. As these disorders are often observed in individuals prenatally exposed to cigarette smoking, we tested the hypothesis that such exposure impairs central myelination in adolescence, an important period of brain development and the peak age of onset of psychiatric disorders. Pregnant Sprague Dawley rats were treated with nicotine (3 mg kg−1 per day; gestational nicotine (GN)) or gestational saline via osmotic mini pumps from gestational days 4–18. Both male and female offsprings were killed on postnatal day 35 or 36, and three limbic brain regions, the prefrontal cortex (PFC), caudate putamen and nucleus accumbens, were removed for measurement of gene expression and determination of morphological changes using quantitative real-time PCR (qRT-PCR) array, western blotting and immunohistochemical staining. GN altered myelin gene expression at both the mRNA and protein levels, with striking sex differences. Aberrant expression of myelin-related transcription and trophic factors was seen in GN animals, which correlated highly with the alterations in the myelin gene expression. These correlations suggest that these factors contribute to GN-induced alterations in myelin gene expression and also indicate abnormal function of oligodendrocytes (OLGs), the myelin-producing cells in the CNS. It is unlikely that these changes are attributable solely to an alteration in the number of OLGs, as the cell number was changed only in the PFC of GN males. Together, our findings suggest that abnormal brain myelination underlies various psychiatric disorders and drug abuse associated with prenatal exposure to cigarette smoke. PMID:23591971

  19. Gestational nicotine exposure modifies myelin gene expression in the brains of adolescent rats with sex differences.

    PubMed

    Cao, J; Wang, J; Dwyer, J B; Gautier, N M; Wang, S; Leslie, F M; Li, M D

    2013-01-01

    Myelination defects in the central nervous system (CNS) are associated with various psychiatric disorders, including drug addiction. As these disorders are often observed in individuals prenatally exposed to cigarette smoking, we tested the hypothesis that such exposure impairs central myelination in adolescence, an important period of brain development and the peak age of onset of psychiatric disorders. Pregnant Sprague Dawley rats were treated with nicotine (3 mg kg(-1) per day; gestational nicotine (GN)) or gestational saline via osmotic mini pumps from gestational days 4-18. Both male and female offsprings were killed on postnatal day 35 or 36, and three limbic brain regions, the prefrontal cortex (PFC), caudate putamen and nucleus accumbens, were removed for measurement of gene expression and determination of morphological changes using quantitative real-time PCR (qRT-PCR) array, western blotting and immunohistochemical staining. GN altered myelin gene expression at both the mRNA and protein levels, with striking sex differences. Aberrant expression of myelin-related transcription and trophic factors was seen in GN animals, which correlated highly with the alterations in the myelin gene expression. These correlations suggest that these factors contribute to GN-induced alterations in myelin gene expression and also indicate abnormal function of oligodendrocytes (OLGs), the myelin-producing cells in the CNS. It is unlikely that these changes are attributable solely to an alteration in the number of OLGs, as the cell number was changed only in the PFC of GN males. Together, our findings suggest that abnormal brain myelination underlies various psychiatric disorders and drug abuse associated with prenatal exposure to cigarette smoke. PMID:23591971

  20. Modified GFAP promoter auto-regulates tet-activator expression for increased transactivation and reduced tTA-associated toxicity.

    PubMed

    Barton, Michael D; Dunlop, J W; Psaltis, G; Kulik, J; DeGennaro, L; Kwak, Seung P

    2002-05-30

    Transactivator tTA is a necessary component of the tetracycline-regulated inducible gene system. While several transgenic animals have been described that express tTA in the central nervous system (CNS), their tTA levels are often limited, presumably due to toxic effects. We evaluated methods for auto-regulating tTA levels in astrocytes by modifying the transgenic promoter human GFAP (hGFAP). The hGFAP promoter carrying a single copy of the tet-operon in place of a native enhancer element (GFAPtetO1) drove expression of tTA at low levels during un-stimulated, basal condition. However the same promoter auto-induced expression of tTA to significant levels after tetracycline withdrawal. Glial cell-specificity of the promoter remained uncompromised during both basal and induced conditions. Transgenic rats were developed using the auto-inducible GFAPtetO1 promoter that expressed tTA mRNA to high levels in the brain. Expression was widespread within the CNS but enriched in astrocyte-rich regions including the cerebellum. Primary cerebellar astrocytes from GFAPtetO1 rats transfected with 07LacZ produced substantially greater inducibility of reporter gene compared to GFAP-tTA transgenic rats. Finally, GFAPtetO1 rats exhibited severe motor/gait deficit when bred to homozygosity. This phenotype was attributable to developmental abnormalities of the cerebellum and was completely abrogated by doxycycline administration. These results suggest that developmental toxicity resulting from tTA expression can be circumvented and tTA transgenics with high transactivation potential can be developed using the auto-activation strategy. Promoter modification presented here may be useful in developing highly inducible transgenic strategies without loss in tissue-specificity. PMID:12007834

  1. Suppression of Transgene Silencing by Matrix Attachment Regions in Maize

    PubMed Central

    Brouwer, Cory; Bruce, Wesley; Maddock, Sheila; Avramova, Zoya; Bowen, Ben

    2002-01-01

    Matrix attachment regions (MARs) are DNA sequences that bind an internal nuclear network of nonhistone proteins called the nuclear matrix. Thus, they may define discrete gene-containing chromatin loops in vivo. We have studied the effects of flanking transgenes with MARs on transgene expression levels in maize callus and in transformed maize plants. Three MAR elements, two from maize (Adh1 5′ MAR and Mha1 5′ MAR) and one from yeast (ARS1), had very different effects on transgene expression that bore no relation to their affinity for the nuclear matrix in vitro. In callus, two of the MAR elements (Adh1 5′ MAR and ARS1) reduced transgene silencing but had no effect on the variability of expression. In transgenic plants, Adh1 5′ MAR had the effect of localizing β-glucuronidase expression to lateral root initiation sites. A possible model accounting for the function of Adh1 5′ MAR is discussed. PMID:12215518

  2. MGFD: the maize gene families database

    PubMed Central

    Sheng, Lei; Jiang, Haiyang; Yan, Hanwei; Li, Xiaoyu; Lin, Yongxiang; Ye, Hui; Cheng, Beijiu

    2016-01-01

    Most gene families are transcription factor (TF) families, which have fundamental roles in almost all biological processes (development, growth and response to environmental factors) and have been employed to manipulate various types of metabolic, developmental and stress response pathways in plants. Maize (Zea mays) is one of the most important cereal crops in the world due its importance to human nutrition and health. Thus, identifying and annotating all the gene families in maize is an important primary step in defining their functions and understanding their roles in the regulation of diverse biological processes. In this study, we identified 96 predicted maize gene families and systematically characterized all 5826 of the genes in those families. We have also developed a comprehensive database of maize gene families (the MGFD). To further explore the functions of these gene families, we extensively annotated the genes, including such basic information as protein sequence features, gene structure, Gene Ontology classifications, phylogenetic relationships and expression profiles. The MGFD has a user-friendly web interface with multiple browse and search functions, as well as data downloading. The MGFD is freely available to users at http://mgfd.ahau.edu.cn/. Database URL: http://mgfd.ahau.edu.cn/ PMID:26896848

  3. MGFD: the maize gene families database.

    PubMed

    Sheng, Lei; Jiang, Haiyang; Yan, Hanwei; Li, Xiaoyu; Lin, Yongxiang; Ye, Hui; Cheng, Beijiu

    2016-01-01

    Most gene families are transcription factor (TF) families, which have fundamental roles in almost all biological processes (development, growth and response to environmental factors) and have been employed to manipulate various types of metabolic, developmental and stress response pathways in plants. Maize (Zea mays) is one of the most important cereal crops in the world due its importance to human nutrition and health. Thus, identifying and annotating all the gene families in maize is an important primary step in defining their functions and understanding their roles in the regulation of diverse biological processes. In this study, we identified 96 predicted maize gene families and systematically characterized all 5826 of the genes in those families. We have also developed a comprehensive database of maize gene families (the MGFD). To further explore the functions of these gene families, we extensively annotated the genes, including such basic information as protein sequence features, gene structure, Gene Ontology classifications, phylogenetic relationships and expression profiles. The MGFD has a user-friendly web interface with multiple browse and search functions, as well as data downloading. The MGFD is freely available to users at http://mgfd.ahau.edu.cn/. Database URL: http://mgfd.ahau.edu.cn/. PMID:26896848

  4. RNA Expression Microarray Analysis in Mouse Prospermatogonia: Identification of Candidate Epigenetic Modifiers

    PubMed Central

    Lefèvre, Christophe; Mann, Jeffrey R.

    2011-01-01

    The mammalian totipotent and pluripotent lineage exhibits genome-wide dynamics in respect to DNA methylation content. The first phase of global DNA demethylation and de novo remethylation occurs during preimplantation development and gastrulation, respectively, while the second phase occurs in primordial germ cells and primary oocytes/prospermatogonia, respectively. These dynamics are indicative of a comprehensive epigenetic resetting or reprogramming of the genome in preparation for major differentiation events. To gain further insight into the mechanisms driving DNA methylation dynamics and other types of epigenetic modification, we performed an RNA expression microarray analysis of fetal prospermatogonia at the stage when they are undergoing rapid de novo DNA remethylation. We have identified a number of highly or specifically expressed genes which could be important for determining epigenetic change in prospermatogonia. These data provide a useful resource in the discovery of molecular pathways involved in epigenetic reprogramming in the mammalian germ line. PMID:18330932

  5. Alteration of enod40 expression modifies medicago truncatula root nodule development induced by sinorhizobium meliloti

    PubMed Central

    Charon, C; Sousa, C; Crespi, M; Kondorosi, A

    1999-01-01

    Molecular mechanisms involved in the control of root nodule organogenesis in the plant host are poorly understood. One of the nodulin genes associated with the earliest phases of this developmental program is enod40. We show here that transgenic Medicago truncatula plants overexpressing enod40 exhibit accelerated nodulation induced by Sinorhizobium meliloti. This resulted from increased initiation of primordia, which was accompanied by a proliferation response of the region close to the root tip and enhanced root length. The root cortex of the enod40-transformed plants showed increased sensitivity to nodulation signals. T(1) and T(2) descendants of two transgenic lines with reduced amounts of enod40 transcripts (probably from cosuppression) formed only a few and modified nodulelike structures. Our results suggest that induction of enod40 is a limiting step in primordium formation, and its function is required for appropriate nodule development. PMID:10521525

  6. Changing calcium: CRAC channel (STIM and Orai) expression, splicing, and posttranslational modifiers.

    PubMed

    Niemeyer, Barbara A

    2016-05-01

    A wide variety of cellular function depends on the dynamics of intracellular Ca(2+) signals. Especially for relatively slow and lasting processes such as gene expression, cell proliferation, and often migration, cells rely on the store-operated Ca(2+) entry (SOCE) pathway, which is particularly prominent in immune cells. SOCE is initiated by the sensor proteins (STIM1, STIM2) located within the endoplasmic reticulum (ER) registering the Ca(2+) concentration within the ER, and upon its depletion, cluster and trap Orai (Orai1-3) proteins located in the plasma membrane (PM) into ER-PM junctions. These regions become sites of highly selective Ca(2+) entry predominantly through Orai1-assembled channels, which, among other effector functions, is necessary for triggering NFAT translocation into the nucleus. What is less clear is how the spatial and temporal spread of intracellular Ca(2+) is shaped and regulated by differential expression of the individual SOCE genes and their splice variants, their heteromeric combinations and pre- and posttranslational modifications. This review focuses on principle mechanisms regulating expression, splicing, and targeting of Ca(2+) release-activated Ca(2+) (CRAC) channels. PMID:26911279

  7. Regulating expression of cell and tissue-specific genes by modifying transcription

    SciTech Connect

    Beachy, Roger N; Dai, Shunhong

    2010-06-14

    Transcriptional regulation is the primary step to control gene expression, therefore function. Such regulation is achieved primarily via a combination of the activities of the promoter cis regulatory DNA elements and trans regulatory proteins that function through binding to these DNA elements. Rice bZIP transcription factors RF2a, RF2b and RLP1 play key roles in regulating the activity of a vascular tissue specific promoter isolated from Rice Tungro Bacilliform Virus (RTBV), through their interactions with the Box II essential cis element located in the promoter (Dai et al., 2006., Dai et al., 2004., Yin et al., 1997). RF2a, RF2b and RLP1 possess multiple regulatory domains. Functional characterization reveals that those domains can activate or repress the activity of the RTBV promoter. It is equally as important to recognize that these proteins control plant development by regulating differentiation and/or function of the vascular tissues. Studies of transcriptional regulation of the RTBV promoter by this group of bZIP proteins will not only provide insights about gene expression in the vascular tissue, but also insights about general mechanisms of transcription activation and repression. The knowledge gained from this research will also enable us to develop a well-described set of tools that can be used to control expression of multiple genes in transgenic plants. We have proposed characterize the function domains of RF2a, RF2b and RLP1 and explore the biological function of the transcription repressor RLP1.

  8. Mono-2-ethylhexyl phthalate disrupts neurulation and modifies the embryonic redox environment and gene expression.

    PubMed

    Sant, Karilyn E; Dolinoy, Dana C; Jilek, Joseph L; Sartor, Maureen A; Harris, Craig

    2016-08-01

    Mono-2-ethylhexl phthalate (MEHP) is the primary metabolite of di-2-ethylhexyl phthalate (DEHP), a ubiquitous contaminant in plastics. This study sought to determine how structural defects caused by MEHP in mouse whole embryo culture were related to temporal and spatial patterns of redox state and gene expression. MEHP reduced morphology scores along with increased incidence of neural tube defects. Glutathione (GSH) and cysteine (Cys) concentrations fluctuated spatially and temporally in embryo (EMB) and visceral yolk sac (VYS) across the 24h culture. Redox potentials (Eh) for GSSG/GSH were increased by MEHP in EMB (12h) but not in VYS. CySS/CyS Eh in EMB and VYS were significantly increased at 3h and 24h, respectively. Gene expression at 6h showed that MEHP induced selective alterations in EMB and VYS for oxidative phosphorylation and energy metabolism pathways. Overall, MEHP affects neurulation, alters Eh, and spatially alters the expression of metabolic genes in the early organogenesis-stage mouse conceptus. PMID:27167697

  9. The progesterone and estrogen modify the uterine prolactin and prolactin receptor expression of hyperprolactinemic mice.

    PubMed

    do Amaral, Vinícius Cestari; Carvalho, Kátia Candido; Maciel, Gustavo Arantes Rosa; Simoncini, Tommaso; da Silva, Priscilla Ludovico; Marcondes, Rodrigo Rodrigues; Soares, José Maria; Baracat, Edmund Chada

    2015-02-01

    The aim of this study was to evaluate the effects of metoclopramide-induced hyperprolactinemia on the prolactin (PRL) and PRL receptor's expression in the uterus of mice. For this purpose, 49 Swiss mice were divided into the following groups: GrSS (non-ovariectomized mice given vehicle); GrMET (non-ovariectomized mice treated with metoclopramide); OvSS (ovariectomized mice given vehicle); OvMET (ovariectomized mice treated with metoclopramide); OvMET+17βE (ovariectomized mice treated with metoclopramide and 17β estradiol); OvMET+MP (ovariectomized mice treated with metoclopramide and micronized progesterone); OvMET+17βE+MP (ovariectomized mice treated with metoclopramide and a solution of 17β estradiol and micronized progesterone). Immunohistochemical analyzes were evaluated semi-quantitatively. Our results showed that GrMET, OvMET+MP, and OvMET+17βE+MP presented strong PRL expression. OvMET and OvMET+17βE presented mild reaction, while GrSS and OvSS presented weak reaction. Concerning PRL receptor, OvMET+MP and OvMET+17βE+MP showed strong reaction; GrMET, OvSS, and OvMET+17βE showed mild reaction; and GrSS and OvMET showed weak reaction. These findings suggest that progesterone alone or in combination with estrogen may increase the expression of uterine PRL and PRL receptor. PMID:25299230

  10. A Neuronal Activity-Dependent Dual Function Chromatin-Modifying Complex Regulates Arc Expression1,2,3

    PubMed Central

    Oey, Nicodemus E.; Leung, How Wing; Ezhilarasan, Rajaram; Zhou, Lei; Beuerman, Roger W.; VanDongen, Hendrika M.A.

    2015-01-01

    Abstract Chromatin modification is an important epigenetic mechanism underlying neuroplasticity. Histone methylation and acetylation have both been shown to modulate gene expression, but the machinery responsible for mediating these changes in neurons has remained elusive. Here we identify a chromatin-modifying complex containing the histone demethylase PHF8 and the acetyltransferase TIP60 as a key regulator of the activity-induced expression of Arc, an important mediator of synaptic plasticity. Clinically, mutations in PHF8 cause X-linked mental retardation while TIP60 has been implicated in the pathogenesis of Alzheimer’s disease. Within minutes of increased synaptic activity, this dual function complex is rapidly recruited to the Arc promoter, where it specifically counteracts the transcriptionally repressive histone mark H3K9me2 to facilitate the formation of the transcriptionally permissive H3K9acS10P, thereby favoring transcriptional activation. Consequently, gain-of-function of the PHF8−TIP60 complex in primary rat hippocampal neurons has a positive effect on early activity-induced Arc gene expression, whereas interfering with the function of this complex abrogates it. A global proteomics screen revealed that the majority of common interactors of PHF8 and TIP60 were involved in mRNA processing, including PSF, an important molecule involved in neuronal gene regulation. Finally, we proceeded to show, using super-resolution microscopy, that PHF8 and TIP60 interact at the single molecule level with PSF, thereby situating this chromatin modifying complex at the crossroads of transcriptional activation. These findings point toward a mechanism by which an epigenetic pathway can regulate neuronal activity-dependent gene transcription, which has implications in the development of novel therapeutics for disorders of learning and memory. PMID:26464965

  11. Physical and genetic structure of the maize genome reflects its complex evolutionary history.

    PubMed

    Wei, Fusheng; Coe, Ed; Nelson, William; Bharti, Arvind K; Engler, Fred; Butler, Ed; Kim, HyeRan; Goicoechea, Jose Luis; Chen, Mingsheng; Lee, Seunghee; Fuks, Galina; Sanchez-Villeda, Hector; Schroeder, Steven; Fang, Zhiwei; McMullen, Michael; Davis, Georgia; Bowers, John E; Paterson, Andrew H; Schaeffer, Mary; Gardiner, Jack; Cone, Karen; Messing, Joachim; Soderlund, Carol; Wing, Rod A

    2007-07-01

    Maize (Zea mays L.) is one of the most important cereal crops and a model for the study of genetics, evolution, and domestication. To better understand maize genome organization and to build a framework for genome sequencing, we constructed a sequence-ready fingerprinted contig-based physical map that covers 93.5% of the genome, of which 86.1% is aligned to the genetic map. The fingerprinted contig map contains 25,908 genic markers that enabled us to align nearly 73% of the anchored maize genome to the rice genome. The distribution pattern of expressed sequence tags correlates to that of recombination. In collinear regions, 1 kb in rice corresponds to an average of 3.2 kb in maize, yet maize has a 6-fold genome size expansion. This can be explained by the fact that most rice regions correspond to two regions in maize as a result of its recent polyploid origin. Inversions account for the majority of chromosome structural variations during subsequent maize diploidization. We also find clear evidence of ancient genome duplication predating the divergence of the progenitors of maize and rice. Reconstructing the paleoethnobotany of the maize genome indicates that the progenitors of modern maize contained ten chromosomes. PMID:17658954

  12. Effect of MIR604 transgenic maize at different stages of development on western corn rootworm (Coleoptera: Chrysomelidae) in a central missouri field environment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The establishment and survival of western corn rootworm, Diabrotica virgifera virgifera LeConte, was evaluated on transgenic Bt maize, Zea mays L., expressing the mCry3A protein (MIR604) and non-Bt maize with the same genetic background (isoline maize) at different stages of development in 2007 and ...

  13. A novel naturally occurring tandem promoter in modified vaccinia virus ankara drives very early gene expression and potent immune responses.

    PubMed

    Wennier, Sonia T; Brinkmann, Kay; Steinhäußer, Charlotte; Mayländer, Nicole; Mnich, Claudia; Wielert, Ursula; Dirmeier, Ulrike; Hausmann, Jürgen; Chaplin, Paul; Steigerwald, Robin

    2013-01-01

    Modified vaccinia virus Ankara (MVA) has been shown to be suitable for the generation of experimental vaccines against cancer and infectious diseases, eliciting strong humoral and cellular immune responses. In viral vectored vaccines, strong recombinant antigen expression and timing of expression influence the quantity and quality of the immune response. Screening of synthetic and native poxvirus promoters for strong protein expression in vitro and potent immune responses in vivo led to the identification of the MVA13.5L promoter, a unique and novel naturally occurring tandem promoter in MVA composed of two 44 nucleotide long repeated motifs, each containing an early promoter element. The MVA13.5L gene is highly conserved across orthopoxviruses, yet its function is unknown. The unique structure of its promoter is not found for any other gene in the MVA genome and is also conserved in other orthopoxviruses. Comparison of the MVA13.5L promoter activity with synthetic poxviral promoters revealed that the MVA13.5L promoter produced higher levels of protein early during infection in HeLa cells and particularly in MDBK cells, a cell line in which MVA replication stops at an early stage before the expression of late genes. Finally, a recombinant antigen expressed under the control of this novel promoter induced high antibody titers and increased CD8 T cell responses in homologous prime-boost immunization compared to commonly used promoters. In particular, the recombinant antigen specific CD8 T cell responses dominated over the immunodominant B8R vector-specific responses after three vaccinations and even more during the memory phase. These results have identified the native MVA13.5L promoter as a new potent promoter for use in MVA vectored preventive and therapeutic vaccines. PMID:23951355

  14. A Novel Naturally Occurring Tandem Promoter in Modified Vaccinia Virus Ankara Drives Very Early Gene Expression and Potent Immune Responses

    PubMed Central

    Wennier, Sonia T.; Brinkmann, Kay; Steinhäußer, Charlotte; Mayländer, Nicole; Mnich, Claudia; Wielert, Ursula; Dirmeier, Ulrike; Hausmann, Jürgen; Chaplin, Paul; Steigerwald, Robin

    2013-01-01

    Modified vaccinia virus Ankara (MVA) has been shown to be suitable for the generation of experimental vaccines against cancer and infectious diseases, eliciting strong humoral and cellular immune responses. In viral vectored vaccines, strong recombinant antigen expression and timing of expression influence the quantity and quality of the immune response. Screening of synthetic and native poxvirus promoters for strong protein expression in vitro and potent immune responses in vivo led to the identification of the MVA13.5L promoter, a unique and novel naturally occurring tandem promoter in MVA composed of two 44 nucleotide long repeated motifs, each containing an early promoter element. The MVA13.5L gene is highly conserved across orthopoxviruses, yet its function is unknown. The unique structure of its promoter is not found for any other gene in the MVA genome and is also conserved in other orthopoxviruses. Comparison of the MVA13.5L promoter activity with synthetic poxviral promoters revealed that the MVA13.5L promoter produced higher levels of protein early during infection in HeLa cells and particularly in MDBK cells, a cell line in which MVA replication stops at an early stage before the expression of late genes. Finally, a recombinant antigen expressed under the control of this novel promoter induced high antibody titers and increased CD8 T cell responses in homologous prime-boost immunization compared to commonly used promoters. In particular, the recombinant antigen specific CD8 T cell responses dominated over the immunodominant B8R vector-specific responses after three vaccinations and even more during the memory phase. These results have identified the native MVA13.5L promoter as a new potent promoter for use in MVA vectored preventive and therapeutic vaccines. PMID:23951355

  15. Identification of Ssm1b, a novel modifier of DNA methylation, and its expression during mouse embryogenesis.

    PubMed

    Ratnam, Sarayu; Engler, Peter; Bozek, Grazyna; Mao, Liqun; Podlutsky, Andrej; Austad, Steve; Martin, Terence; Storb, Ursula

    2014-05-01

    The strain-specific modifier Ssm1 is responsible for the strain-dependent methylation of particular E. coli gpt-containing transgenic sequences. Here, we identify Ssm1 as the KRAB-zinc finger (ZF) gene 2610305D13Rik located on distal chromosome 4. Ssm1b is a member of a gene family with an unusual array of three ZFs. Ssm1 family members in C57BL/6 (B6) and DBA/2 (D2) mice have various amino acid changes in their ZF domain and in the linker between the KRAB and ZF domains. Ssm1b is expressed up to E8.5; its target transgene gains partial methylation by this stage as well. At E9.5, Ssm1b mRNA is no longer expressed but by then its target has become completely methylated. By contrast, in D2 embryos the transgene is essentially unmethylated. Methylation during B6 embryonic development depends on Dnmt3b but not Mecp2. In differentiating B6 embryonic stem cells methylation spreads from gpt to a co-integrated neo gene that has a similarly high CpG content as gpt, but neo alone is not methylated. In adult B6 mice, Ssm1b is expressed in ovaries, but in other organs only other members of the Ssm1 family are expressed. Interestingly, the transgene becomes methylated when crossed into some, but not other, wild mice that were kept outbred in the laboratory. Thus, polymorphisms for the methylation patterns seen among laboratory inbred strains are also found in a free-living population. This may imply that mice that do not have the Ssm1b gene may use another member of the Ssm1 family to control the potentially harmful expression of certain endogenous or exogenous genes. PMID:24803651

  16. Differentially Expressed Genes Distributed Over Chromosomes and Implicated in Certain Biological Processes for Site Insertion Genetically Modified Rice Kemingdao

    PubMed Central

    Liu, Zhi; Li, Yunhe; Zhao, Jie; Chen, Xiuping; Jian, Guiliang; Peng, Yufa; Qi, Fangjun

    2012-01-01

    Release of genetically modified (GM) plants has sparked off intensive debates worldwide partly because of concerns about potential adverse unintended effects of GM plants to the agro system and the safety of foods. In this study, with the aim of revealing the molecular basis for unintended effects of a single site insertion GM Kemingdao (KMD) rice transformed with a synthetic cry1Ab gene, and bridging unintended effects of KMD rice through clues of differentially expressed genes, comparative transcriptome analyses were performed for GM KMD rice and its parent rice of Xiushui11 (XS11). The results showed that 680 differentially expressed transcripts were identified from 30-day old seedlings of GM KMD rice. The absolute majority of these changed expression transcripts dispersed and located over all rice chromosomes, and existed physical distance on chromosome from the insertion site, while only two transcripts were found to be differentially expressed within the 21 genes located within 100 kb up and down-stream of the insertion site. Pathway and biology function analyses further revealed that differentially expressed transcripts of KMD rice were involved in certain biological processes, and mainly implicated in two types of pathways. One type was pathways implicated in plant stress/defense responses, which were considerably in coordination with the reported unintended effects of KMD rice, which were more susceptible to rice diseases compared to its parent rice XS11; the other type was pathways associated with amino acids metabolism. With this clue, new unintended effects for changes in amino acids synthesis of KMD rice leaves were successfully revealed. Such that an actual case was firstly provided for identification of unintended effects in GM plants by comparative transciptome analysis. PMID:22811617

  17. Preparation and functional evaluation of RGD-modified streptavidin targeting to integrin-expressing melanoma cells.

    PubMed

    Syrkina, Marina S; Shirokov, Dmitry A; Rubtsov, Mikhail A; Kadyrova, Elena L; Veiko, Vladimir P; Manuvera, Valentin A

    2013-02-01

    The vertical growth stage is the most dangerous stage of melanoma and is often associated with a poor prognosis. The increa