Project description:Heat stress along with other abiotic stresses is one of the major factors affecting crop health and overall yield in a tropical country like India. Thus, there is an urgent need to understand the dynamics of heat responsiveness at the molecular as well as physiological level. Fortunately, India has a number of indigenous varieties that show tolerance to extremes in temperature during the scorching summer months. The cultivar Annapurna is a fast growing dwarf variety of rice that is heat tolerant while the most widely grown indica rice in South and Southeast Asia, IR64, is susceptible to high temperatures. These two cultivars present an excellent opportunity to study the differences in response to heat stress, and, thereby help in elucidating the genes involved in conferring tolerance to high temperature. The present study involves transcript profiling of the two cultivars, Annapurna (tolerant) and IR64 (susceptible) under both control and heat stressed conditions.
Project description:In order to evaluate the genome differences and find the more tolerant cultivar, first eleven Malaysian rice cultivars namely, MR219, MR276, MR220, MR211, MR219-4, MR253, Q50, Q74, MR159, Masuri and MR263 were subjected under water deficit. Then, based on the morphological and physiological traits, the more drought-tolerant and -susceptible cultivars were screened and time-course gene expression profiling established by a comprehensive transcriptome database sequencing of the leaf RNA of tolerant rice. The current investigation provides pivotal data for understanding the rice drought tolerance mechanisms.
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:An indica rice cultivar FR13A, is widely grown as submergence tolerant variety and can withstand submergence up to two weeks. The tolerance is governed by a major QTL on chromosome 9 and represented as sub1. Recently the gene for sub1 has been mapped and cloned. However, the trait is governed by several QTLs and not by a single gene. To understand the mechanism of submergence 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 submerged conditions at seedling stage. Keywords: Mechanism of submergence tolerance
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:An indica rice cultivar FR13A, is widely grown as submergence tolerant variety and can withstand submergence up to two weeks. The tolerance is governed by a major QTL on chromosome 9 and represented as sub1. Recently the gene for sub1 has been mapped and cloned. However, the trait is governed by several QTLs and not by a single gene. To understand the mechanism of submergence 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 submerged conditions at seedling stage. SUBMITTER_CITATION: Combining In Silico Mapping and Arraying: an Approach to Identifying Common Candidate Genes for Submergence Tolerance and Resistance to Bacterial Leaf Blight in Rice. Mol. Cells 2007 24:394-408. Experiment Overall Design: We used Agilent rice gene chips (G4138A) to investigate the transcript level changes in rice leaf tissues during submergence treatment. We used two contrasting rice genotypes (FR13A tolerant and IR24 susceptible) differing in submergence response. Plants were grown in growth chambers and treated by submerging the plants in transparent polythene bags on14th DAS. Leaf 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.
Project description:Rice reproductive development is highly sensitive to high temperature stress. In rice flowering occurs over a period of at least 5 days. Heat stress alters the global gene expression dynamics in panicle especially during pollen development, anthesis and grain filling. Some of the rice genotypes like Nagina 22 show better spikelet fertility and grain filling compared to high yielding and popular rice cultivars like IR 64. We carried out microarray analysis of 8 days heat stressed panicles of Nagina22, heat and drought tolerant aus rice cultivar and IR64, a heat susceptible indica genotype along with unstressed samples of Nagina22 and IR64 so as to understand the transcriptome dynamics in these two genotypes under heat stress and to identify the genes important for governing heat stress tolerance in rice.