Project description:Drought avoidance mechanism is one of the component mechanisms contributing for drought tolerance in which roots serves as the master keys, but poorly understood. Comparative analysis of drought stress responsive root transcriptome between drought-tolerant Nootripathu and drought-susceptible IR20 In this study, we used microarrays to dissect out drought responsive changes in roots of two contrasting rice genotypes viz., IR 20 (a shallow rooted lowland indica genotype) and Nootripathu (a deep rooted upland indica genotype) at molecular level.
Project description:Under natural conditions, plants experience episodes of drought for periods of days or longer. Plants respond to drought stress by reconfiguring their transcriptome activity. Transcriptome changes in response to drought are dynamic, and are likely to be shaped by mitigating factors such as diel signals. To gain insights into the dynamics of transcriptome reconfiguration in response to gradual soil drying, the drought-induced transcriptomes of Arabidopsis thaliana were examined at four time points over a single diel period – midday, late day, midnight, and pre-dawn. A core set of genes was identified that was responsive to drought, independent of the time of day at which they were measured. Strikingly, the magnitude of the drought-induced changes for these genes varied in a time-of-day-dependent manner. An additional set of time-of-day-specific drought-responsive genes were also identified. The diurnal patterns of transcript accumulation for these genes was strongly influenced by drought stress. This study indicates that analysis of a single time point would miss suites of drought-responsive genes that are revealed through assessment of the dynamics of diurnal changes, emphasizing the value of characterizing multiple time-of-day-specific drought transcriptomes.
Project description:To understand the transcriptome changes during drought tolerance in maize, the drought-tolerant line Han21 and drought-sensitive line Ye478, which show substantial differences in drought tolerance at the seedling stage, were selected for this study. Using the GeneChip Maize Genome Arrays, we applied genome-wide gene expression analysis to the two genotypes under gradual drought stress and re-watering. We identified 2172 common regulated transcripts in both lines under drought stress, with 1084 common up-regulated transcripts and 1088 common down-regulated transcripts. Among the 2172 transcripts, 58 potential protein kinases and 117 potential transcription factors were identified. The potential components of the ABA signaling pathway were identified from the common regulated transcripts. We also identified 940 differentially regulated transcripts between the two lines. Among the 940 transcripts, the differential expression levels of 29 transporters and 15 cell wall-related transcripts may contribute to the different tolerances of the two lines. Additionally, we found that the drought-responsive genes in the tolerant Han21 line recovered more quickly when the seedlings were re-watered, and 311 transcripts in the tolerant Han21 line were exclusively up-regulated at the re-watering stage compared to the control and stress conditions. Our study provides a global characterization of two maize inbred lines during drought stress and re-watering and will be valuable for further study of the molecular mechanisms of drought tolerance in maize.
Project description:To understand the transcriptome changes during drought tolerance in maize, the drought-tolerant line Han21 and drought-sensitive line Ye478, which show substantial differences in drought tolerance at the seedling stage, were selected for this study. Using the GeneChip Maize Genome Arrays, we applied genome-wide gene expression analysis to the two genotypes under gradual drought stress and re-watering. We identified 2172 common regulated transcripts in both lines under drought stress, with 1084 common up-regulated transcripts and 1088 common down-regulated transcripts. Among the 2172 transcripts, 58 potential protein kinases and 117 potential transcription factors were identified. The potential components of the ABA signaling pathway were identified from the common regulated transcripts. We also identified 940 differentially regulated transcripts between the two lines. Among the 940 transcripts, the differential expression levels of 29 transporters and 15 cell wall-related transcripts may contribute to the different tolerances of the two lines. Additionally, we found that the drought-responsive genes in the tolerant Han21 line recovered more quickly when the seedlings were re-watered, and 311 transcripts in the tolerant Han21 line were exclusively up-regulated at the re-watering stage compared to the control and stress conditions. Our study provides a global characterization of two maize inbred lines during drought stress and re-watering and will be valuable for further study of the molecular mechanisms of drought tolerance in maize. In two independent experiments, we generate maize gene expression profiles during drought stress and re-watering through comparing genome-wide expression patterns of drought stress treatment and re-watering treatment by using 17,555 Affymetrix maize whole genome array.
Project description:Under natural conditions, plants experience episodes of drought for periods of days or longer. Plants respond to drought stress by reconfiguring their transcriptome activity. Transcriptome changes in response to drought are dynamic, and are likely to be shaped by mitigating factors such as diel signals. To gain insights into the dynamics of transcriptome reconfiguration in response to gradual soil drying, the drought-induced transcriptomes of Arabidopsis thaliana were examined at four time points over a single diel period â midday, late day, midnight, and pre-dawn. A core set of genes was identified that was responsive to drought, independent of the time of day at which they were measured. Strikingly, the magnitude of the drought-induced changes for these genes varied in a time-of-day-dependent manner. An additional set of time-of-day-specific drought-responsive genes were also identified. The diurnal patterns of transcript accumulation for these genes was strongly influenced by drought stress. This study indicates that analysis of a single time point would miss suites of drought-responsive genes that are revealed through assessment of the dynamics of diurnal changes, emphasizing the value of characterizing multiple time-of-day-specific drought transcriptomes. 24 arrays total. 4 time points (midday, late day, midnight, pre-dawn). 2 water regimes (well-watered, water-limited). 3 biological replicates per treatment.
Project description:Drought is a major limitation to the growth and productivity of trees in the ecologically and economically important genus Populus. The ability of Populus trees to contend with drought is a function of the responsiveness of their genome to this environmental insult, involving reconfiguration of the transcriptome to appropriately remodel growth, development and metabolism. The Populus drought transcriptome is shaped by interspecific genotypic variation, but the extent to which intraspecific variation shapes the drought transcriptome has not yet been examined. Here we test hypotheses aimed at examining the extent of intraspecific variation in the drought transcriptome. Transcriptome remodeling in response to water-deficit conditions was examined in six different Populus balsamifera L. genotypes using Affymetrix GeneChip technology. There were significant differences in the transcriptomes of the genotypes in response to water-deficit conditions; however, a common species-level response could also be identified across all individuals. Genotypes that had more similar drought-responsive transcriptomes also had fewer genotypic differences, as determined by microarray-derived single feature polymorphism (SFP) analysis, suggesting that responses may be conserved across individuals that share a greater degree of genotypic similarity. This work highlights the fact that a core species-level response can be defined; however, the underpinning genotype-derived complexities of the drought response in Populus must be taken into consideration when defining both species- and genus-level responses. 72 arrays total. 6 genotypes, 2 time points. 2 water regimes. 3 biological replicates per treatment
Project description:Drought is a major limitation to the growth and productivity of trees in the ecologically and economically important genus Populus. The ability of Populus trees to contend with drought is a function of the responsiveness of their genome to this environmental insult, involving reconfiguration of the transcriptome to appropriately remodel growth, development and metabolism. The Populus drought transcriptome is shaped by interspecific genotypic variation, but the extent to which intraspecific variation shapes the drought transcriptome has not yet been examined. Here we test hypotheses aimed at examining the extent of intraspecific variation in the drought transcriptome. Transcriptome remodeling in response to water-deficit conditions was examined in six different Populus balsamifera L. genotypes using Affymetrix GeneChip technology. There were significant differences in the transcriptomes of the genotypes in response to water-deficit conditions; however, a common species-level response could also be identified across all individuals. Genotypes that had more similar drought-responsive transcriptomes also had fewer genotypic differences, as determined by microarray-derived single feature polymorphism (SFP) analysis, suggesting that responses may be conserved across individuals that share a greater degree of genotypic similarity. This work highlights the fact that a core species-level response can be defined; however, the underpinning genotype-derived complexities of the drought response in Populus must be taken into consideration when defining both species- and genus-level responses.
Project description:Drought is a harmful abiotic stress that threatens the growth, development, and yield of rice plants. To cope with drought stress, plants have evolved diverse and sophisticated stress-tolerance pathways by regulating gene expression. Previous genome-wide studies have revealed many rice drought stress-responsive genes that are involved in various metabolism, hormone biosynthesis and signaling pathways, and transcriptional regulation. However, little is known about the regulation of drought-responsive genes during rehydration after dehydration. In this study, we examined the dynamic gene expression patterns in rice seedling shoots during dehydration and rehydration using RNA-seq analysis. To investigate the transcriptome-wide rice gene expression patterns during dehydration and rehydration, RNA-seq libraries were sequenced and analyzed to identify differentially expressed genes (DEGs). DEGs were classified into five clusters based on their gene expression patterns. The clusters included drought-responsive DEGs that were either rapidly or slowly recovered to control levels by rehydration treatment. Representative DEGs were selected and validated using qRT-PCR. In addition, we performed a detailed analysis of DEGs involved in nitrogen metabolism, phytohormone signaling, and transcriptional regulation. In this study, we revealed that drought-responsive genes were dynamically regulated during rehydration. Moreover, our data showed the potential role of nitrogen metabolism and jasmonic acid signaling during the drought stress response. The transcriptome data in this study could be a useful resource for understanding drought stress responses in rice, and may provide a valuable gene list for developing drought-resistant crop plants.
Project description:Drought is a destructive abiotic stress, with plants possessing diverse strategies to survive periods of limited water resources. Previous results have described connections between strigolactone (SL) and drought, however, here we used the barley (Hordeum vulgare) SL-insensitive mutant hvd14 (dwarf14) to investigate the SL-dependent mechanisms related to water deficit response. By combining transcriptome, proteome with phytohormone analyses and physiological data, we describe the drought-mediated differences between wild-type and hvd14 plants. Our findings indicate that the drought sensitivity of hvd14 is related to weaker induction of abscisic acid-responsive genes/proteins, lower jasmonic acid content, higher reactive oxygen species content, and lower wax biosynthic and deposition mechanisms then wild-type plants. In addition, we identify a series of transcription factors (TFs) that are exclusively drought-induced in wild-type barley. Critically, we resolve a comprehensive series interestions between the drought-induced barley transcriptome and proteome responses that allow us to understand the impacts of SL in mitigating water limiting conditions. These data provide a number of new angles for the development of drought-resistant barley.