Role of Salicylic Acid to Improve Physiological Characters and Bio-Chemical Markers of Soybean (Glycine max L.) Under Sea Salt Stress

Salicylic acid (SA) has a vital role in mechanisms of various physiological processes. The foliar application of salicylic acid at (50 and 100 mg/l) was investigated under two concentrations of sea salt (3000 and 6000 ppm) to alleviate the harmful effect of sea salt on soybean plants. This study indicated that salinity treatments significantly decreased growth parameters of soybean plant at 60 and 80 days after sowings with increasing sea salt concentration. Salinity reduced photosynthetic pigments, N, P, K+ contents and crop yield compared with control plants. Proline content increased in plants under salinity and also with SA treatments compared to the control plants. Foliar application of (SA) on plants treated with sea salt led to alleviate the impact of salts on plant growth, photosynthetic pigments, N, P, K+ contents, proline and seed yield. SA at 50 mg/l had an ability to ameliorate the adverse effects of sea salt on plants than 100 mg/l SA. Salinity conditions and SA treatment exhibited differences in the soluble protein patterns by SDS-PAGE technique. Plants treated with SA appeared polypeptide with molecular weights of 97 KD. The effect of salinity stress produced a new protein band with molecular weight of 110 KD which considered as biochemical markers for adapting soybean with salinity.