Expression pattern of genes encoding carbonic anhydrase, peroxidase and glutathione S-transferase enzymes in bread wheat under zinc deficiency conditions

One of the plant strategies against stresses, especially micronutrient deficiencies, is the use of enzymatic antioxidant defense system. To investigate the effect of Zn deficiency on the genes expression of carbonic anhydrase (CAN), peroxidase (PRX) and glutathione S-transferase (GST) enzymes in Zn-efficient (Hamun) and -inefficient (Hirmand) bread wheat cultivars, a factorial experiment was carried out in completely randomized design (CRD) with three replications in greenhouse. The cultivars were grown in Zn deficient (zero) and adequacy (5 mg Zinc per kg soil) conditions and relative expression of the studied genes was measured using real time PCR technique in root and leaf of the cultivars at two growth stages, one month after germination (vegetative stage) and 30 % of flowering (reproductive stage). The results revealed the highest increase in CAN  (211 fold) expression in the root of Zn-efficient (Hamoon) cultivar in the reproductive stage. A realtively high expression of this gene was observed in the leaf of both cultivars in the reproductive stage. The highest increase in PRX (187 fold) and GST (230 fold)  expression was observed in the leaf of Zn-inefficient (Hirmand) cultivar at the reproductive stage. Generally, the expression of all three studied genes in the root of Zn-efficient (Hamoon) cultivar in the reproductive stage was higher than those of Zn-inefficient (Hirmand) cultivar. Also, the CAN expression in the leaf of Zn-efficient cultivar was significantly higher than that of Zn-inefficient cultivar. In conclusion, the results of the current study show that in the reproductive stage, Zn-efficient cultivars can effectively face against stress-induced damages through increasing the expression of the above-mentioned genes in the roots under Zn deficiency conditions.