Expression pattern of anti-oxidant genes in wheat wild relatives under water deficit stress

Wild relatives of wheat have served as an ideal gene pool for improving drought tolerance in wheat. The objective of this study was to investigate the expression patterns of several antioxidant genes comprising MnSOD, APX and GPX in the different cultivated and wild wheat species under control (90% field capacity) and drought stress (25% field capacity) conditions. For this purpose, a factorial experiment based on randomized complete block design with four replications (two biological and two technical replications) was conducted to compare five species of Aegilops and two species of Triticum along with two bread wheat check cultivars SIRVAN (as resistant to drought) and DARYA (as sensitive to drought) in greenhouse. The analysis of variance for the relative gene expression values showed significant effects for the drought stress, species and their interaction. Drought stress increased expression of MnSOD, APX and GPX by 9.55, 12.64 and 10.18-fold more than the control condition, respectively. Moreover, the results obtained by species comparison indicated a differential expression pattern of these genes among species. As a remarkable result Ae. tauschii, Ae. speltoides and Ae. cylindrica species showed higher expression than other species as well as the tolerant control variety when subjected to a high level of drought stress. Therefore, further studies on these species to determine the mechanisms associated with tolerance to drought stress are recommended.