De Novo Transcriptome Sequencing for Characterizing the Plasticity of Carbon Assimilatory Pathway in Wheat under Terminal Heat Stress

Wheat, being staple food grain crops, provides 12% of the carbohydrate and 40% of the calories in the diet. The grains of wheat is dominated with carbohydrates along with other beneficial nutrients required for balanced diet. This crop is highly sensitive to heat stress, especially during pollination and grain-filling stages. Heat stress causes pollen sterility, drying of stigmatic surface, improper fertilization, partial starch granule synthesis, empty pockets, defragmented granules and ultimately shriveled grains with low nutrient density. Even slight fluctuation in temperature has been reported to disturbed the source to sink ratio which is reflected in terms of decrease in the quantity and quality of the grains. The present investigation has been undertaken with two contrasting wheat cvs. - HD2967 (Thermotolerant) and BT-Schomburgk (thermosusceptible) sown under normal and delayed conditions and samples (leaves and spikes) were collected at uniform dough stage (based on Feekes scale) for whole transcriptome sequencing in order to elucidate the mechanism underlying carbon assimilation under terminal heat stress.