H2O2 seed priming improves tolerance to salinity stress in durum wheat

These days, priming is widely used as an effective procedure to elevate the resistance of plants under salinity stress. In the present research, Behrang and Arya cultivars, which were identified as the most resistant and sensitive durum wheat cultivars under salinity stress in our previous study, were considered as the plant materials. Three different conditions, including control, salinity stress, and H2O2 priming + salinity stress environment, were selected as our environments in this research. According to the data obtained from leaf samples, the amounts of chlorophyll a, b (Chla, Chlb), besides total carotenoids (Car), decreased in response to salinity stress, but the exposure of seeds to H2O2 before induction of salinity stress elevated the levels of these pigments, which is completely inverse to the amounts of oxidative stress parameters including electrolyte leakage (El), malondialdehyde (MDA), other aldehydes (OLD), hydrogen peroxide (H2O2). The content of proline (Pro), total soluble carbohydrate (TSC), and total soluble protein (TSP), ascorbate peroxidase (APX), catalase (CAT) and guaiacol peroxidase (GPX) enzymes activity as well as the expression of Pyrroline-5-carboxylate synthase (P5CS), Pyrroline-5-carboxylate reductase (P5CR), NAC29, NAC6, Triticum durum branched-chain amino acid aminotransferases (TdBCAT), TdBCAT-A and TdBCAT-B genes elevated under salinity stress and also H2O2 priming + salinity stress. However, the amounts of increase for these parameters in response to H2O2 priming + salinity stress are significantly higher than that of salinity stress condition. To conclude, it is clear that seed priming with H2O2 can increase the tolerance of wheat or, most likely other plants under salinity stress.