Differences in the drought stress response of DREB2 and CAT1 genes and evaluation of related physiological parameters in some bread wheat cultivars

Abiotic stresses such as drought are among the most significant environmental stress causes in economically important crop plants including wheat (Triticum aestivum L.) and improving their yield is a major goal of plant breeding. In this study, we analysed expression of dehydration responsive element binding factor (DREB2), and an important antioxidant enzyme gene CAT1 in flag leaf of three bread wheat cultivars named Kavir, Kalheydari and Shahpasand under drought stress by RT-qPCR. In another section, physiological parameters including catalase enzyme (EC 1.11.1.6), relative water content (RWC) and chlorophyll content (a,b and total) were analysed. The cultivars were planted in a randomized complete block design with three replicates in normal and drought stress conditions on experimental field in 2013. Differential expression patterns of the genes DREB2 and CAT1 were observed in cultivars. The observed trend was the high induction in the expression of genes under drought stress. The expression of DREB2 was more than CAT1 in drought stress. The relative genes expression showed significant correlation with the catalase, RWC and chlorophyll b. Under drought stress, Kavir had higher expression of DREB2 and CAT1, activity of catalase, RWC, chlorophyll content (a, b and total) than the other cultivars. According to increasing of drought tolerance through the expression of these genes, it can be concluded that transferring of these genes may enhance drought tolerance in high-yield wheat cultivars.