Exogenous Application of Salicylic Acid Improves Growth and Yield of Black Gram Vigna mungo L. by Improving Antioxidant Defense Mechanism under Saline Conditions

The current experiment was designed to evaluate the effect of salicylic acid (SA) on the growth, physiological, biochemical, antioxidant and agronomic parameters of black gram Vigna mungo (L.) Hepper under salinity stress. One group of experimental plants of V. mungo varieties ADT-5 was treated with 75 mM NaCl, and the other group was kept without NaCl as control. Various concentrations of SA (0.5, 0.75, and 1 mM) were sprayed on the experimental plant to test its effect. Under salinity stress, the morpho-biochemical parameters were significantly reduced in the salt-treated plant. The results revealed that SA foliar spray mitigated the salinity-induced adverse effect on plant. The apparent increase in chlorophyll a by 81%, chlorophyll b by 63%, carotenoid by 25%, decreased malondialdehyde by 5% and electrolyte leakage by 29% was reported using SA (0.5 mM) foliar spray under salt stress. Foliar application of SA enhanced proline content and enzymatic antioxidants enzymes viz., catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), and glutathione reductase (GR) activity of V. mungo by 18, 29, 46, 37, and 38%, respectively, compared to the control group. It was revealed that foliar application of SA could enhance the yield of the V. mungo under salt stress conditions. Our results demonstrated that SA mitigated the deleterious impact of salt stress and may be used as a tool to enhance food production under global climate change.