NaCl induced oxidative stress in legume crops of Indian Thar Desert: an insight in the cytoprotective role of HO1, NO and antioxidants

The manuscript highlights the role of antioxidants in alleviation of salinity stress in two principal legume crops Cyamopsis tetragonoloba and Vigna radiata of Indian Thar Desert. The study evaluates correlation between the antioxidants of two cultivars in terms of morphological and physiological alterations. Hydroponically acclimatized seedlings of both the crops were subjected to NaCl stress at different concentrations ranges from 10 to 100 mM. After 96 h, the treated legumes were harvested to analyze the cellular homeostasis and salt tolerance mechanism via examining growth, stress parameters, osmoprotectants and enzymatic antioxidants. Differential response in the antioxidants activity was observed in crops. Equal contribution of antioxidants in mitigation of salinity stress was recorded in C. tetragonoloba while V. radiata shows greater tolerance by accumulating greater amount of proline which is approximately 2.72 folds higher than C. tetragonoloba. Moreover, the NR and HO1 activities in V. radiata were recorded to be 2.76 and 1.55 folds respectively which is 1.2 times higher in comparison to C. tetragonoloba. The detrimental effect of NaCl in terms of MDA content was also higher in V. radiata which concluded that V. radiata is more reactive towards salinity stress than C. tetragonoloba. The study is significant as this is the first report illustrating the sensitivity and tolerance level of NaCl in legumes of Thar Desert.