Transcriptional profiling of indica rice cultivar FR13A under submergence treatment.

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 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.