Salinity-Induced Stress in Lentil ( Lens culinaris ): Growth Inhibition, Oxidative Damage, and Antioxidant Defense Strategies

Salinity stress severely restricts lentil productivity worldwide. This study examines two lentil varieties (L4147 and L4729) to determine how salinity affects growth indicators, morphology, photosynthetic pigments, nitrate reductase activity, carbonic anhydrase activity, and leghemoglobin and antioxidant systems. The experimental setup was maintained in the net house of the Botany Department, Aligarh Muslim University, throughout the rabi season. On the 20th day after sowing, the plants were subjected to salinity treatments by applying NaCl solutions at concentrations of 0, 50, 100, 150, and 200 mM to separate sets of plants. Observations were recorded on the 45th day after sowing. With increased salt concentration, growth, leaf area, fresh and dry biomass, photosynthetic pigments, leghemoglobin, protein content, carbonic anhydrase activity, nitrate reductase activity, and mitotic index significantly decrease under salt stress in both varieties, according to observations that have been recorded. However, compared to L4729, these changes were quantitatively less pronounced in L4147. Furthermore, salinity-induced oxidative stress increased MDA and proline content by 36.34 and 62.14% and 56.11 and 40.44%, along with the antioxidant activities of peroxidase by 54.55% and 35.71%, superoxide dismutase by 51.26 and 55.74%, and catalase by 44.80 and 42.73% in L4147 and L4729, respectively. Salt stress was found to affect variety L4729 more than L4147. Future indicators can be derived from these two varieties, as determined by their antioxidant defense mechanism, photosynthetic pigments, and stomatal behavior. Overall, the findings indicate that L4147 possesses superior adaptive mechanisms to salinity stress, positioning it as a promising variety for cultivation in salt-affected environments.