Shikha YashveerMehndiratta, Ravi2017-12-142017-12-142017http://krishikosh.egranth.ac.in/handle/1/5810037511The present investigation was conducted to study the expression profile of ADP - glucose pyrophosphorylase (AGPase) large subunit for thermo-tolerance in developing grains of two genotypes (WH 711 and WH 730) of wheat under two different sowing conditions (normal and late sown). Gene expression and AGPase activity was studied at six different stages of grain filling (4, 8, 12, 16, 20 and 24DAA) along with physiomorphological and yield attributes. Under conditions of heat stress, there was a considerable reduction in grain yield/ plant, plant height, number of tillers and 1000 grain weight in thermosensitive genotype (WH 711) as compared to thermotolerant genotype (WH 730). The activity of AGPase was correlated with data obtained through expression profiling; the activity and expression of AGPase large subunit was highest at 20DAA for thermotolerant genotype (WH730) under both NS and LS conditions. In case of thermo sensitive genotype (WH711), the activity peaked at 20DAA under normal sown conditions and 16 DAA under late sown conditions; the activity was seized at 24 DAA after anthesis under NS and LS conditions. Putative cDNA obtained were sequenced for WH 711(1270bp) and WH 730 (1247bp). Cladogram generated using different AGPase large subunit sequences clustered WH 711 and WH 730 into different groups; WH 730 sequence was phylogenitically more similar to the sequence a cquired from AGPase large subunit of barley. This study supported the role of AGPase for thermotolerance in wheat by getting insights of the expression and enzyme activity at different stages of grain filling in LS as well under NS conditions; thus providing a deep understanding for the biologists working with ADP-glucose pyrophosphorylase in order to understand the functionality of AGPase .ennullThesis