Assessment of Antioxidant Enzyme Activity and Mineral Nutrients in Response to NaCl Stress and its Amelioration Through Glutathione in Chickpea

Salinity stress has been reckoned as one of the major threat towards crop productivity as it causes significant decline in the yield. The impact of NaCl stress (0, 1, 10, 50, 100 and 200 mg L-1) as well as glutathione (10 mg L-1) either alone or in combination has been evaluated on the induction of multiple shoots, antioxidant enzymes' activity, lipid peroxidation, relative permeability, concentration of nutrients, photosynthetic pigments, protein and proline content of nodal segments of chickpea after 14 days of culture. The antioxidant enzyme activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (GPX) and glutathione reductase (GR) were found to be increased under salt stress as well as glutathione-supplemented medium. A significant decrease in the concentrations of chlorophylls a, b, total chlorophyll and carotenoid was observed under salt stress. Concentrations of nitrogen, phosphorus, potassium, calcium, carbon, magnesium and sulphur showed an initial increase up to 10 mg L-1 NaCl, but a decline was seen at higher NaCl levels. Proline content and malondialdehyde concentration were found to be increased under salt stress. Three isoforms of SOD, one of CAT and four of GPX were expressed during native polyacrylamide gel electrophoresis (PAGE) analysis. However, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of the stressed nodal explants revealed the over-expression of several polypeptide bands related to NaCl stress. These findings for the first time suggest that glutathione (GSH) helps in ameliorating NaCl stress in nodal explants of chickpea by manipulating various biochemical and physiological responses of plants.