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 NaClstress was studied in leaves of two varieties of pea (Pisum sativum L.) cv. EC 33866 and Puget. Thelevel of lipid peroxidation, enzyme activity of superoxide dismutase (SOD, EC 1.15.1.1), ascorbateperoxidase (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 thanPuget. Significant accumulation in the levels of Na+ and Cl- was observed in Puget as theconcentration of salt increased. Decrease in levels of K+, Ca2+ and Mg2+ was recorded in bothvarieties but Puget showed more decrease as compared to EC 33866. Salt stress increased the rate oflipid peroxidation in both the varieties of pea but more decrease was observed in Puget. Salt stressinduced significant increase in the activities of the antioxidant enzymes. The SOD and APX increasedin both varieties at all concentrations but the increase was more in EC 33866 variety than Puget. GRand DHAR were increased in both the varieties at 150 mM NaCl, however at 200 mM NaCl declinewas observed. Decline of DHAR and GR was more pronounced in Puget as compared to the EC33866 variety.