Project description:Closely related lineages can possess phenotypic variation important for adaptation and the evolution of new species; a phenomenon that can be more clearly elucidated by studying hybrid generations. We compare variation in gene expression in response to drought for two taxa and advanced-generation hybrids of the Piriqueta cistoides ssp. caroliniana complex that differ in their levels of tolerance to water limitation. Drought treatments lasted 36 days, through four cycles of drought. Gene expression in drought and control treatments was assessed using heterologous hybridization to a Glycine max microarray. There was a predominance of down-regulated genes in response to sustained drought in all morphotypes. This pattern was more pronounced in the hybrids, which can exhibit greater drought tolerance under field and greenhouse conditions than the parental morphotypes. Expression response profiles were more similar between the hybrid and the drought-tolerant parental morphotype than they were between the hybrid and the parental morphotype that occurs in more mesic habitats. Predominant down-regulation of gene expression contrasts with studies of response to short-term drought and with studies of drought-response in annual and non-drought-tolerant model species, and supports the results of a growing number of studies with other drought-tolerant perennial plants under prolonged drought.
Project description:Closely related lineages can possess phenotypic variation important for adaptation and the evolution of new species; a phenomenon that can be more clearly elucidated by studying hybrid generations. We compare variation in gene expression in response to drought for two taxa and advanced-generation hybrids of the Piriqueta cistoides ssp. caroliniana complex that differ in their levels of tolerance to water limitation. Drought treatments lasted 36 days, through four cycles of drought. Gene expression in drought and control treatments was assessed using heterologous hybridization to a Glycine max microarray. There was a predominance of down-regulated genes in response to sustained drought in all morphotypes. This pattern was more pronounced in the hybrids, which can exhibit greater drought tolerance under field and greenhouse conditions than the parental morphotypes. Expression response profiles were more similar between the hybrid and the drought-tolerant parental morphotype than they were between the hybrid and the parental morphotype that occurs in more mesic habitats. Predominant down-regulation of gene expression contrasts with studies of response to short-term drought and with studies of drought-response in annual and non-drought-tolerant model species, and supports the results of a growing number of studies with other drought-tolerant perennial plants under prolonged drought. A total of 18 array hyridizations. Two conditions (drought and control), three morphotypes (caroliniana, viridis, and hybrid), for a total of 6 morphotype/treatment combinations. Three samples of each morphotypes/treatment combination were hybridized twice in dye swap in a loop design.
Project description:comprehensive and quantitative proteomic study of the roots of the NH4+-tolerant legume Medicago truncatula grown with nitrate, NH4+ or urea as sole N source using the iTRAQ method.
Project description:Lotus japonicus is a perennial legume with a small diploid genome that has been adopted as a model species for legume genetics and genomics. With the genome sequence as a backdrop (Sato et al. 2008), we have generated a gene expression atlas that provides a global view of gene expression in all major organ systems of this species, including nodule and seed development.
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:Genome-wide Transcriptional Analysis of Genes Associated with Drought Stress in Gossypium herbaceum root This experiment was designed to investigate the molecular mechanism associated with drought tolerance in root tissue of Gossypium herbaceum. The gene expression profiles of the root tissue using Affymetrix Cotton Genome Array were compared with drought tolerant and drought sensitive genotype of G.herbaceum under drought stress and watered condition. Many genes in various molecular function or biological processes were over- or under-represented between drought tolerant and sensitive genotype, suggesting various molecular mechanism and biochemical pathways are interlinked and tolerant genotype have developed multiple mechanisms as an adaptory behavior against drought stress.
Project description:Drought often compromises yield in non-irrigated crops such as rainfed rice, imperiling the communities that depend upon it as a primary food source. In this study, two cultivated species (Oryza sativa cv. Nipponbare and Oryza glaberrima cv. CG14) and an endemic, perennial Australian wild species (Oryza australiensis) were grown in soil at 40% field capacity for 7-d (drought). The hypothesis was that the natural tolerance of O. australiensis to erratic water supply would be reflected in a unique proteomic profile. Leaves from droughted plants and well-watered controls were harvested for label-free quantitative shotgun proteomics. Physiological and gene ontology analysis confirmed that O. australiensis is responded uniquely to drought, with superior leaf water status and enhanced levels of photosynthetic proteins. Moreover, distinctive patterns of expression of proteins in drought were observed across the entire O. australiensis proteome. An intermediate impact of drought on photosynthetic and stress-response proteins is reported in O. glaberrima relative to O. sativa but the drought response was most striking in O. australiensis. For example, photosynthetic proteins decreased when O. sativa after drought, while a narrower range of stress-responsive proteins was up-regulated. Distinctive proteomic profiles and the expression levels of individual proteins with specific functions in response to drought in O. australiensis indicate the importance of this species as a source of stress tolerance genes.
Project description:Grafting is a well-established practice for grapevine to facilitate propagation of productive and tolerant cultivars against several stress factors. It is also considered to be a suitable method for studying molecular aspects of root-to-shoot and/or shoot-to-root signaling events. So far, controlling only effect of rootstock over scion was investigated and root-to-shoot transcriptomic alterations were fallowed on the scions or graft interfaces. The objective of this study was to investigate transcriptomic and physiological influence of scion on the rootstock under drought stress. Therefore, drought tolerant 110R rootstock were firstly grafted with sultana seedless and tested under drought stress with its non-grafted counterpart. The results of treatment indicated that grafted 110R performed the highest root elongation under drought. We carried out a microarray based transcriptome analysis on the roots of grafted and non-grafted 110R to explain this drought derived interaction through scion-to-rootstock. The highest expression increase under drought was recorded for sugar (SWEET) and nitrate or di/tri-peptide (NRT1/ PTR FAMILY) transporter proteins. Expression level of these genes was more highly increased in grafted 110R than its non-grafted counterpart. This situation indicated their potential role in drought tolerance and scion/rootstock harmony. Overexpression of these transporters attributed to increased amount of released nutrient and nitrogen source from abscised leaves of sultana seedless under drought. Remobilization of these rich sources was suggested to chance transcriptomic response of rootstocks and enabled much better growth in grafted 110R. Other transcripts annotated to cell wall modification enzymes (chitinases), osmoregulator proteins (dehydrins, proline-glycine rich proteins) and secondary metabolites (stilbene synthase) were also more highly induced in grafted 110R. This is the first report indicating transcriptomic influence of scion on the grapevine rootstocks and representing the genes responsible in scion/rootstock harmony and drought tolerance.
Project description:Leaf samples were used. We exposed young seedlings to NaCl and drought. Expression study in 24hrs salt and drought condition. Salt-sensitive and salt-tolerant strains of rice exposed to NaCl or control conditions. Drought-sensitive and drought-tolerant strains of rice exposed to drought or control conditions.