Assessment of TaNAC2A Gene Expression and Ascorbate Peroxidase, Catalase Enzymes of Five Durum Wheat Genotypes (Triticum turgidum L.) Under Drought Stress

To deal with stresses, especially drought stress, identification of resistance genes in plants and understanding their functions is very important. In this study, we investigated the effects of drought stress on expression of TaNAC2A gene as well as on the activity of ascorbate peroxidase and catalase in some of the durum wheat genotypes. The experiment was conducted in factorial based on randomized complete block design with five drought stress levels (5, 10, 15, 20 and 25% of field capacity) and  five durum wheat genotypes (Shabrang, Behrang. Karkhe, Arya and Dena) in three replications. The genotypes were planted in pots and different levels of drought stress were induced at seedling stage (four leaves). Variance analysis showed that the effects of genotype, drought stress and drought stress×genotype interaction were significantly different compare with the control (25% FC). Drought stress of 5% field capacity had the greatest influence on TaNAC2A expression as well as catalase and ascorbate peroxidase enzymes activity. The level of TaNAC2A expression and the activity of catalase and glycol peroxidase enzymes in Shabrang genotype were higher than that in other genotypes. Interestingly, with increasing drought stress levels, the TaNAC2A expression and antioxidant activity of catalase and ascorbate peroxidase was increased in all tested genotypes. Moreover Shabrang genotype had the highest TaNAC2A gene expression during drought stress of 5% field capacity compared with the control.