Evaluation of physiological and protein response of tolerant and scuseptible wheat cultivars to different concentration of drought stresses

Identification of drought tolerant wheat cultivars in Iran which is one of the world's arid and semi arid countries has particular importance. For this purpose and for evaluation the response to drought stress imposed with different concentrations of PEG6000 an experiment was conducted using two cultivars of spring wheat in seedling stage with hydroponic culture method. The used plant materials in this research as factorial basis on completely randomized design with four replications were evaluated. The stress factor in this experiment included control (using no PEG6000) and drought stress imposed with PEG6000 10% (-0.26MP), PEG6000 15% (-0.39MP) and PEG6000 20% (-0.52MP) volumetric. Also the second factor was two spring wheat cultivars as tolerant (Niknejhad) and susceptible (Pishtaz). Two weeks after the imposing the drought stress and at the end of rosette stage, samples were collected. The results showed that value of physiological traits decreased under stress condition and two studied cultivars were varied in response to drought stress. For evaluation of protein pattern using proteome analysis, protein extraction from leaf texture was performed and the first dimensional electrophoresis using IPG strips and the second dimension electrophoresis were done by SDS-PAGE technique for both control and stressed plants in both cultivars. Then, staining with commassie brilliant blue, gel imaging and protein spot analysis were performed with PDQuest software. Finally, 23 significant protein spots between control and drought plants for both two cultivars were detected that of these, 14 protein spots were common between the two cultivars and five protein spots were unique to tolerant cultivar and four protein spots were unique to susceptible cultivar. Overall, it seems that the highest common protein groups between the two cultivars were the proteins involved in the photosynthesis optical reaction and detoxifying proteins. Also, the type of responsive unique protein in two cultivars of tolerant and susceptible were different under stress. In total, the most important reason for the sensitivity and tolerance of spring wheat cultivars was the different amounts of these proteins and, finally, their effect on other traits studied.