The alleviating effects of selenium and salicylic acid in salinity exposed soybean

This research was conducted to screen various treatments of selenium (Se) and/or salicylic acid (SA) to mitigate signs of salinity on soybean. Seedlings were treated with three concentrations of Se (0, 25 and 50 mg l(-1)), two concentrations of SA (0 and 0.5 mM) and/or two concentrations of NaCl (0 and 100 mM). Se and/or SA had significant enhancing and alleviating effects on the chlorophyll a (Chl a) and carotenoid contents as well as, Chl a/b in the treated plants, but had adverse effects on the Chl b concentrations. The limiting effects of salinity on leaf area and dry mass were significantly eased by the Se and/or SA among which 25 mg l(-1) Se and combined treatment of 50 mg l(-1) Se and SA were the most effective. The utilization of Se and/or SA led to the improved proline and Mg contents, compared to the control. The supplemented Se and/or SA, especially the mixed ones, resulted in a significant decrease in Na/K ratios. Se and/or SA had significant inducing effects on enzymatic (peroxidase, catalase and superoxide dismutase) and non-enzymatic (ascorbate) antioxidant system. On the basis of the obtained results, it could be stated that the foliar utilization of Se in combination with SA may be used to relieve the signs of salinity stress.