Whole Transcriptome Sequencing of Parent and Stable Mutants of Wheat for Elucidating the Tolerance Mechanism under Terminal Heat Stress

Wheat, being staple food grain crops, is highly sensitive to terminal heat stress. Even a slight fluctuation in temperature during critical stages - pollination and grain-filling - has been observed to affect the quantity and quality of the grains. Recent study showed depletion in the nutrient of wheat grains exposed to terminal heat stress. Here, Department of Atomic Energy (DAE), Bhabha Atomic Research Center (BARC), Mumbai developed mutants of wheat for heat stress tolerance using gamma irradiation. The mutants were evaluated for thermotolerance based on morphological, physiological, biochemical characterization and seed yield, and further stable mutants (M-4) along with parents were shared with IARI, New Delhi for further characterization. Forty mutants were further evaluated for thermotolerance using different molecular and biochemical markers for two generations. Based on the evaluation, wheat mutant- 3 was observed promising over the generation. In order to understand the mechanism of thermotolerance and to locate the heat-responsive SNIPs, whole transcriptome sequencing was carried out using the pooled samples (root, stem, leaves and spikes) of Stable Mutant -3 and Parent-3 under control and HS-treated conditions.