A novel strategy of mycorrhizal fungi usage to enhance crop resilience in saline environments: biopriming with Serendipita indica

Soil salinization is a critical global challenge, threatening agricultural productivity by imposing osmotic stress, ionic toxicity, and oxidative imbalance in plants. This study investigated the potential of Serendipita indica biopriming to enhance salt stress tolerance in maize (Zea mays L. cv. Simon) seedlings through comprehensive physiological and biochemical analyses under controlled conditions. Maize seeds were bioprimed with different concentrations of mycorrhizal fungi S. indica spores and exposed to varying NaCl concentrations (0, 50, 100, and 200 mM). Nonprimed maize seedlings had a gradual reduction in seed vigor index, reaching about 93.56% in 200 mM NaCl treatment. Under nonsaline conditions, S. indica biopriming enhanced plant growth parameters. For example, dry weight accumulation increased by 105.80% with biopriming at 1/8 (10.87 × 105) spore concentrations compared to the nonprimed control. Under moderate and severe salinity, nonprimed maize seedlings decreased in growth, relative water content, and chlorophyll level. S. indica biopriming mitigated these effects, maintaining dry mass at 200 mM NaCl comparable to the nonstressed control. Bioprimed seedlings had improved photosynthetic efficiency, attributed to the preservation of chlorophyll content and redox balance. Elevated activities of key antioxidant enzymes, i.e. superoxide dismutase, catalase, and peroxidase, were correlated with reduced levels of oxidative stress markers and minimized membrane damage, thereby maintaining cellular integrity. Additionally, biopriming with S. indica promoted the accumulation of the stress-responsive metabolite proline, suggesting the modulation of stress signaling pathways. T hese findings indicate that S. indica not only mitigated salt-induced stress but also promoted plant growth in salt-free conditions, suggesting its potential as a growth stimulant under both normal and saline environments. This study shows the potential of S. indica biopriming as a sustainable and ecofriendly strategy to mitigate the adverse effects of salinity on crop growth, offering a promising approach to improving agricultural resilience in saline environments.