Responses of proline, lipid peroxidation and antioxidative enzymes in two varieties of Pisum sativum L. under salt stress

The possible involvement of activated oxygen species in the mechanism of damage by NaCl stress was studied in leaves of two varieties of pea (Pisum sativum L.) cv. EC 33866 and Puget. The level of lipid peroxidation, enzyme activity of superoxide dismutase (SOD, EC 1.15.1.1), ascorbate peroxidase (APX, EC 1.11.1.11), glutathione reductase (GR, EC 1.6.4.2), dihydroascorbate reductase (DHAR, 1.8.5.1) were studied. High chlorophyll stability was observed in EC 33866 varieties than Puget. Significant accumulation in the levels of Na+ and Cl- was observed in Puget as the concentration of salt increased. Decrease in levels of K+, Ca2+ and Mg2+ was recorded in both varieties but Puget showed more decrease as compared to EC 33866. Salt stress increased the rate of lipid peroxidation in both the varieties of pea but more decrease was observed in Puget. Salt stress induced significant increase in the activities of the antioxidant enzymes. The SOD and APX increased in both varieties at all concentrations but the increase was more in EC 33866 variety than Puget. GR and DHAR were increased in both the varieties at 150 mM NaCl, however at 200 mM NaCl decline was observed. Decline of DHAR and GR was more pronounced in Puget as compared to the EC 33866 variety.