Exogenous ascorbic acid priming for mitigation of salinity stress in soybean (Glycine max (L.) Merrill) cv. Indira Soy

Soil salinity, a pressing issue in arid and semi-arid regions, severely limits agricultural productivity and threatens food security. Exploring effective strategies to enhance crop resilience is crucial, particularly using natural compounds like ascorbic acid, known to mitigate stress and improve plant performance under adverse conditions. This study investigates the role of ascorbic acid in improving salt stress tolerance in soybean (Glycine max (L.) Merrill) by analysing morpho-physiological, and biochemical parameters. Soybean seeds (cv. Indira soy) were primed with ascorbic acid at concentrations of 25, 50 and 100 mg/L and inoculated into MS medium supplemented with 100 mM NaCl-induced salinity stress. Significant enhancements were observed in treated plants compared to untreated controls. Morphological improvements included a 45% increase in shoot length and a 33% rise in root biomass at 50 mg/L concentration. Photosynthetic efficiency, indicated by chlorophyll and carotenoid content, improved by 28% and 35%, respectively. The antioxidant defence was significantly enhanced, with catalase and superoxide dismutase activities increasing by 35 and 47%, respectively, while lipid peroxidation was reduced by 48%, indicating lower oxidative damage. Furthermore, osmolyte accumulation, including proline (52%) and soluble sugars (43%), contributed to better osmotic adjustment and stress resilience. The results exhibit that ascorbic acid effectively mitigates salt-induced stress in soybean by improving growth, physiological parameters, and oxidative defence mechanisms. This study underscores the potential of ascorbic acid as a cost-effective, sustainable strategy to enhance crop resilience in saline conditions, offering a promising avenue for improved agricultural productivity.