Project description:Plant roots are the primary site of perception and injury for saline-alkaline stress. The current knowledge of the saline-alkaline stress transcriptome is most focused on salt (NaCl) stress. Only a little alkaline (NaHCO3) stress transcriptome is limited to one time point after stress. Time-course analysis and comparative investigation on roots in the alkaline stress condition are needed to understand the gene response networks that are subject to alkaline tolerance. We used microarrays to detail the global programme of gene expression underlying NaHCO3 treatment and identified distinct classes of regulated genes during this process.
Project description:Plant roots are the primary site of perception and injury for saline-alkaline stress. The current knowledge of the saline-alkaline stress transcriptome is most focused on salt (NaCl) stress. Only a little alkaline (NaHCO3) stress transcriptome is limited to one time point after stress. Time-course analysis and comparative investigation on roots in the alkaline stress condition are needed to understand the gene response networks that are subject to alkaline tolerance. We used microarrays to detail the global programme of gene expression underlying NaHCO3 treatment and identified distinct classes of regulated genes during this process. Three week old Glycine soja seedling roots from 3cm root apex were harvested in two independent biological replicates after 0, 0.5, 1, 3, 6, 12 and 24h treatment with 50mmol/L NaHCO3 stress for RNA extraction and hybridization on Affymetrix microarrays. To minimize biological variance, roots from three plants originating from the same experiment, condition and cultivar was pooled.
Project description:A submergence tolerant indica rice cultivar FR13A, was also reported to withstand salt stress and proven in our experiments. The mechanism of tolerance is yet to be studied by forward genetics approach. However, it is known that salt stress tolerance is governed by several QTLs and not by a single gene. To understand the mechanism of such a complex mechanism of salt tolerance we selected, two indica rice genotypes namely, I) FR13A, a tolerant indica variety and ii) IR24, a susceptible genotype for this study. We used the 22K rice Oligoarray from Agilent technologies to study the transcript profile in the leaves of the two contrasting rice genotypes under constitutive and salt stress conditions at seedling stage. Experiment Overall Design: We used Agilent rice gene chips (G4138A) to investigate the transcript level changes in rice plant tissues during salt stress treatment. We used two contrasting rice genotypes (FR13A tolerant and IR24 susceptible) differing in salt stress response. Plants were grown in growth chambers and treated with 150 mM salt concentration at 14th DAS. Sampling was done in both constitutive and treated plants at 3 time points. Two replications of microarray experiments were carried out by hybridizing the RNA from tolerant samples against the susceptible lines on the same slide.
Project description:Rice (Oryza sativa), the major staple food crop is being cultivated under varying ecosystems ranging from irrigated lowland to rainfed upland environments. Improvement in the rice production under drought prone unfavourable environment depends on the development of drought tolerant genotypes which needs thorough understanding of physiological and molecular events behind the tolerance mechanism. There is considerable genetic variation for drought tolerance mechanism within the cultivated gene pool. To understand the diversity of drought response, two indica rice genotypes namely, i) Apo, an up-land drought tolerant indica veriety from Philippines and ii) IR64, a popular high yielding drought susceptible genotype were selected for this study. We used the 22K rice Oligoarray from Agilent technologies to study the transcript profile in the leaves of the two contrasting rice genotypes under control and drought stressed conditions during vegetative phase. Keywords: Drought response We used Agilent rice gene chips (G4138A) to investigate the transcript level changes in rice leaf tissues during drought stress. We used two contrasting rice genotypes (IR64 drought susceptible and Apo drought tolerant) differing in their degree of drought tolerance. Plants were grown under green house conditions and drought stress was imposed on 33rd DAS. Leaf sampling was done in both control and drought stressed plants after 6 days of drought stress. Three replications of microarray experiments were carried out by hybridizing the control samples against the drought stressed samples.
Project description:Low temperature exposure during early vegetative stages limits rice plant’s growth and development. Most genes previously related to cold tolerance in rice are from the japonica subspecies. To help clarify the mechanisms that regulate cold tolerance in young indica rice plants, comparative transcriptome analysis of 6 h cold-treated leaves from two genotypes, cold-tolerant and cold-sensitive, was performed. The cold-tolerant and cold-sensitive genotypes were previously characterized, and are sister lines (derived from the same crossing).
Project description:A submergence tolerant indica rice cultivar FR13A, was also reported to withstand salt stress and proven in our experiments. The mechanism of tolerance is yet to be studied by forward genetics approach. However, it is known that salt stress tolerance is governed by several QTLs and not by a single gene. To understand the mechanism of such a complex mechanism of salt tolerance we selected, two indica rice genotypes namely, I) FR13A, a tolerant indica variety and ii) IR24, a susceptible genotype for this study. We used the 22K rice Oligoarray from Agilent technologies to study the transcript profile in the leaves of the two contrasting rice genotypes under constitutive and salt stress conditions at seedling stage. Keywords: Mechanism of salt tolerance
Project description:Comparative analysis of transcriptome in two wheat genotypes with contrasting levels of draught tolerance. We used microarrays to investigate the global gene expression in response to drought stress.
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:Soil alkalinity greatly affects plant growth and crop productivity. Although RNA-Seq analyses have been conducted to investigate genome-wide gene expression in response to alkaline stress in many plants, the expression of alkali-responsive genes in rice has not previously investigated. In this study, the transcriptomic data were compared between an alkaline-tolerant [WD20342 (WD)] and an alkaline-sensitive [Caidao (CD)] rice cultivar under control and alkaline stress conditions. A total of 962 important alkali-responsive (IAR) genes from highly differentially expressed genes (DEGs) were identified, including 28 alkaline-resistant cultivar-related genes, 771 alkaline-sensitive cultivar-related genes and 163 cultivar-non-specific genes. Gene ontology (GO) analysis suggested the enrichment of IAR genes involved in response to various stimuli or stresses. According to KEGG pathway analysis, the IAR genes were related primarily to plant hormone signal transduction and biosynthesis of secondary metabolites. Additionally, among these 962 IAR genes, 74 were transcription factors and 15 occurred with differential alternative splicing between the different samples after alkaline treatment. Our results provide a valuable resource on alkali-responsive genes and should benefit the improvement of alkaline stress tolerance in rice.
Project description:Rice is sensitive to chilling stress, especially at the seedling stage. To elucidate the molecular genetic mechanisms of chilling tolerance in rice, comprehensive gene expressions of two rice genotypes (chilling-tolerant LTH and chilling-sensitive IR29) with contrasting responses to chilling stress were comparatively analyzed. Results revealed distinct global transcription reprogramming between the two rice genotypes under time-series chilling stress and subsequent recovery conditions. A set of genes with higher basal expression were identified in LTH, indicating their possible role in intrinsic tolerance to chilling stress. Under chilling stress, the major effect on gene expression was up-regulation in LTH and strong repression in IR29. Early responses to chilling stress in both genotypes featured commonly up-regulated genes related to transcription regulation and signal transduction, while functional categories for late phase chilling regulated genes were diverse with a wide range of functional adaptations to continuous stress. Following the cessation of chilling treatments, there was quick and efficient reversion of gene expression in LTH, while IR29 displayed considerably slower recovering capacity at the transcriptional level. In addition, the detection of differentially-regulated TF genes and enriched cis-elements demonstrated that multiple regulatory pathways, including CBF and MYBS3 regulons, were involved in chilling stress tolerance. In present study, comprehensive gene expression using an Affymetrix rice genome array revealed a diverse global transcription reprogramming between two rice genotypes under chilling stress and subsequent recovery conditions. The dominant change in gene expression at low temperature was up-regulation in the chilling-tolerant genotype and down-regulation in the chilling-sensitive genotype. Early responses to chilling stress common to both genotypes featured up-regulated genes related to transcription regulation and signal transduction, while functional categories of LR-chilling regulated genes were clearly diverse with a wide range of functional adaptations. At the end of the chilling treatments, there was quick and efficient reversion of gene expression in LTH, while IR29 displayed considerably slower recovery capacity at the transcriptional level. Finally, analysis of differentially-regulated TF genes and enriched cis-elements demonstrated that multiple regulatory pathways, including CBF and MYBS3 regulons, are involved in chilling stress tolerance. In this study, parallel transcriptomic analysis in two rice genotypes with contrasting chilling-tolerant phenotypes was performed to identify and characterize novel genes involved in chilling stress tolerance in rice.