Project description:To better undersand the effects of drought stress on wheat developing seeds, the transcription profile of early developing wheat seeds under control and drought stress conditions were comparatively analyzed by using the Affymetrix wheat geneChip. Drought stress is a major yield-limiting factor for wheat. Wheat yields are particularly sensitive to drought stress during reproductive development. Early seed development stage is an important determinant of seed size, one of the yield components. We specifically examined the impact of drought stress imposed during postzygotic early seed development in wheat. We imposed a short-term drought stress on plants with day-old seeds and observed that even a short-duration drought stress significantly reduced the size of developing seeds as well as mature seeds. Drought stress delayed the developmental transition from syncytial to cellularized stage of endosperm. Coincident with reduced seed size and delayed endosperm development, a subset of genes associated with cytoskeleton organization was misregulated in developing seeds under drought-stressed. Several genes linked to hormone pathways were also differentially regulated in response to drought stress in early seeds. Notably, drought stress strongly repressed the expression of wheat storage protein genes such as gliadins, glutenins and avenins as early as 3 days after pollination. Our results provide new insights on how some of the early seed developmental events are impacted by water stress, and the underlying molecular pathways that can possibly impact both grain size and quality in wheat.
Project description:Wheat seed dormancy is released by after-ripening, and germination and seminal root growth of after-ripened/non-dormant seeds can be inhibited by treatment with exogenous ABA. We used Affymetrix GeneChip Wheat Genome Array to detail transcriptional programs affected by after-ripening of dormant seeds and imbibition of after-ripened seeds in ABA.
Project description:Background: MicroRNAs regulate various biological processes in plants. Considerable data are available on miRNAs involved in the development of rice, maize and barley. In contrast, little is known about miRNAs and their functions in the development of wheat. In this study, five small RNA (sRNA) libraries from wheat seedlings, flag leaves, and developing seeds were developed and sequenced to identify miRNAs and understand their functions in wheat development. Results: Twenty-four known miRNAs belonging to 15 miRNA families were identified from 18 MIRNA loci in wheat in the present study, including 15 (9 MIRNA loci) first identified in wheat, 13 miRNA families (16 MIRNA loci) being highly conserved and 2 (2 MIRNAs loci) moderately conserved. In addition, fifty-five novel miRNAs were also identified. The potential target genes for 15 known miRNAs and 37 novel miRNAs were predicted using strict criteria, and these target genes are involved in a wide range of biological functions. Four of the 15 known miRNA families and 22 of the 55 novel miRNAs were preferentially expressed in the developing seeds with logarithm of the fold change of 1.0~7.6, and half of them were seed-specific, suggesting that they participate in regulating wheat seed development and metabolism. From 5 days post-anthesis to 20 days post-anthesis, miR164 and miR160 increased in abundance in developing seeds, whereas miR169 decreased, suggesting their coordinating functions in the different developmental stages of wheat seed. Moreover, eight known miRNA families and 28 novel miRNAs exhibited tissue-biased expression in wheat flag leaves, with the logarithm of the fold changes of 0.5~5.2. The putative targets of these tissue-preferential miRNAs were involved in various metabolism and biological processes, suggesting complexity of the regulatory networks in different tissues. Our data also suggested that wheat flag leaves have more complicated regulatory networks of miRNAs than developing seeds. Conclusions: Our work identified and characterised wheat miRNAs, their targets and expression patterns. This study is the first to elucidate the regulatory networks of miRNAs involved in wheat flag leaves and developing seeds, and provided a foundation for future studies on specific functions of these miRNAs.
Project description:Transcriptional profiling of wheat embryos of developing seed comparing seeds grown at low temperature:13˚C with seeds grown at high temperature:25˚C during seed development using wheat 2 cultivars: Norin61 (N61) and Shiroganekomugi (SK). Goal was to determine the effects of temperature on global gene expression.
Project description:Transcriptomic analysis of the embryo and endosperm tissue of maturing wheat seeds of two geneotypes, namely AC Domain and RL4452, was performed We used Affymetrix GeneChip Wheat Genome Array to detail transcriptional programs and regulatory networks underlying seed maturation/desiccation in wheat
Project description:Background: Waterlogging was one of the most serious abiotic stresses in wheat-growing regions of China. There were great differences in waterlogging tolerance among different wheat varieties, and the mechanism of waterlogging tolerance of wheat seeds during germination was unclear. Methods: In order to reveal the adaptability of wheat to waterlogging stress during germination, we analyzed the germination rate and anatomical structure of three wheat seeds, ‘Zhoumai 22’, ‘Bainong 207’ and ‘Bainong 607’. At the same time, Illumina sequencing technology was used to determine the transcriptome of these three wheat varieties during germination. Results: The results showed that there was no significant difference between the germination rate of ‘Bainong 207’ after 3 days of waterlogging treatment and that of the control seeds. However, under waterlogging stress, the degree of emulsification and degradation of endosperm cells was higher than that of the control treatment, and starch granules in endosperm were significantly reduced. Transcriptome data were obtained from seed samples (a total of 18 samples) of three wheat varieties under waterlogging and control treatment. A total of 2,775 differentially expressed genes (DEGs) were identified by comprehensive analysis. In addition, by analyzing the correlation between the expression levels of DEGs and seed germination rates in three wheat varieties under waterlogging stress, it was found that the relative expression levels of 563 and 398 genes were positively and negatively correlated with the germination rate of wheat seeds, respectively. The GO and KEGG analysis found that the difference in waterlogging tolerance of the three wheat varieties was related to the abundance of key genes involved in the glycolysis pathway, the starch and sucrose metabolism pathway, and the lactose metabolism pathway. The ethanol dehydrogenase (ADH) gene in the endosperm of ‘Bainong 607’ was immediately induced after a short period of waterlogging, and the energy provided by glycolysis pathway enabled the seeds of ‘Bainong 607’ to germinate as early as possible, while the expression level of AP2/ERF transcription factor was up-regulated to further enhance its waterlogging tolerance. Conclusions: In general, this study provided a deeper understanding of the mechanisms by which different wheat varieties respond to waterlogging stress during germination.
Project description:Transcriptomic analysis of maintenance of dormancy induced by seed development temperature We used Affymetrix GeneChip Wheat Genome Array to detail transcriptional programs underlying maintenance of dormancy induced by seed development tempearture in imbibing seeds of wheat
Project description:Objective: Germination of wheat maximizes phytochemical content and antioxidant activity while altering chemical composition, gluten content, and pasting properties. We previously reported marked changes in gene expression in soybean prior to germination before the radicle had grown from a seed. The present study investigated whether imibibition induces similar changes in wheat. Methods: Changes in gene expression profiles of wheat during short-term imbibition (0, 16, and 24 h) were evaluated by DNA microarray analysis. Gene Ontology (GO) analysis was carried out to categorize the function of genes with altered expression. The expression of genes encoding enzymes associated with starch breakdown was evaluated by quantitative real-time PCR, and changes in enzymatic activity were assessed with functional assays. Pasting properties of flour made from wheat seeds imbibed for different times were examined with a Rapid Visco Analyzer. The protein profile was determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis, and gluten content was quantified. Results: The GO analysis revealed that genes related to cellulose and cell wall synthesis were upregulated by imbibition for 16 h whereas those associated with polysaccharide catabolism and nucleosome assembly were upregulated in the subsequent 8 h. α-Amylase expression was highest after 24-h imbibition, with a corresponding increase in enzymatic activity. The pasting properties of wheat flour decreased when seeds were imbibed for over 16 h. Gluten was not degraded until 48 h imbibition. Conclusion: Short-term imbibition of wheat can produce a new type of starch with improved physical and functional properties that may be more appealing to consumers.
Project description:After-ripening induced seed dormancy release in wheat is associated with mRNA oxidation. We used Affymetrix GeneChip Wheat Genome Array to identify mRNAs differentially oxidized by after-ripening Dormant and after-ripened seeds in dry state were used for isolating oxidized mRNAs and hybridization on Affymetrix GeneChip. After-ripened seeds were generated by storing dormant seeds at room temperature for 10 months.
Project description:Wheat (Triticum aestivum L.), one of the most important crops in the world, is a staple food used for making flour, noodles, alcoholic beverages, biofuel and a variety of other products. In wheat, kernel texture and biochemical composition vary with different hardnesses. Previous study of our research group indicated that physiological properties changes including germination ratio, and physiological enzymatic activities in wheat with different hardnesses were different. A comparative proteomic analysis of soft and hard wheat embryos by our research group identified more proteins associated with anti-resistance in soft wheat than that in hard wheat. Additionally, quantitative proteomic analysis of medium-hard wheat ‘Aikang58’ seeds showed that 162 differentially expressed proteins (DEPs) participated in metabolism, energy supply, and defense/stress responses were identified during artificial ageing were identified in our previous research. However, the dynamic physiological and quantitative proteomic changes in soft wheat seeds during accelerated aging remain unclear, thus need to be elucidated. In this work, we conducted the first Tandem Mass Tag (TMT)-based dynamic quantitative proteomic analysis of elite Chinese soft wheat cultivar ‘Yangmai 15’ seeds during artificial ageing. The uncovered differentially expressed proteins (DEPs) with different functions might provide new insights into the comprehensive understanding of deterioration in soft wheat seeds.