Amelioration Effect of Salicylic Acid Under Salt Stress in Sorghum bicolor L.

Abstract

Salinity is a major abiotic stress, limiting plant growth and agriculture productivity worldwide. Salicylic acid is known to alleviate the negative effects of salinity. The present study demonstrated the impact of SA on sorghum, a moderately salt-tolerant crop, grown for food, fodder, fiber, and fuel. A screen house experiment was conducted using sorghum genotypes Haryana Jowar HJ 513 and HJ 541 under 4 salt levels (0, 5.0, 7.5, and 10.0 dS m-1 NaCl) and 3 SA (0, 25, and 50 mg dm-3) levels with 12 combinations. The leaves were assayed for electrolyte leakage percentage (ELP), i.e., 88.7 % in HJ 541 and 87.2 % in HJ 513, and osmolyte content. Proline content, total soluble carbohydrate content, and glycine betaine content increased considerably. Photosynthetic rate, transpiration rate, and stomatal conductance declined at higher salt levels. The specific enzymatic activities of SOD, CAT, and POX increased 41.1 %, 122.0 %, and 72.8 %, respectively, in HJ 513 under salt stress. Combinations of salt treatment and SA decreased ELP and enhanced osmolyte concentration, rates of gaseous exchange attributes, and also the antioxidant enzymatic activity in salt-stressed leaves. The study established that the specific activity of antioxidative enzymes is enhanced further by addition of SA which may protect the cells from oxidative damage under salt stress, thus mitigating salt stress and enhancing the yield of sorghum. SA can ameliorate the salt stress in plants by affecting the metabolic or physiological frameworks. SA application is an effective management strategy towards mitigating salt stress in order to meet agricultural production and sustainability.