Salicylic Acid Seed Priming Enhances Lentil Germination and Seedling Vigor under Salinity Stress

Salicylic acid (SA), a plant-derived phenolic compound, acts as a signaling molecule that regulates controlling diverse plant responses and plays a role in plant defense under stress conditions. This study aimed to assess the potential of SA seed priming in mitigating the negative effects of salt stress on lentil germination and early seedling development. The germination and vigor of seeds primed with five different doses of SA (0, 0.25, 0.5, 0.75, and 1 mM) were tested at five salinity levels (0, 50, 100, 150 and 200 mM) in peat-perlite. The research was conducted using a completely randomized design with factorial arrangement under greenhouse conditions. Results indicated that low concentrations of SA (0.25 mM) had positive effects on days to seedling emergence, emergence energy (EE), emergence percentage (EP), emergence rate index (ERI), mean emergence time (MET), peak value (PV) and seedling vigor index suggesting that SA can enhance germination and seedling emergence under high salinity. However, as SA concentration increased, a decrease in emergence rate was observed, indicating that higher SA levels may have inhibitory effects on seed performance after sowing. The results also show that SA pre-treatment can significantly improve shoot length, root length, fresh shoot weight, and fresh root weight of lentil seedlings exposed to NaCl stress. Adverse effects of increasing NaCl concentrations were noted for all measured traits, with shoot length, root length, fresh shoot weight, and fresh root weight decreasing, and, no growth observed at the highest NaCl concentration (200 mM). In conclusion, SA can be effectively used in seed priming to mitigate salinity stress during early lentil growth, but the effectiveness of this treatment depends on the salinity level.