Antioxidant Responses of Peanut (Arachis hypogaea L.) Seedlings to Prolonged Salt-Induced Stress

Abstract

In this study, the effects of long-term NaCl treatment were investigated in two cultivars of peanut designated as drought-resistant and drought-sensitive. Growth parameters, changes in the concentrations of MDA, H<inf>2</inf>O<inf>2</inf> and proline, and the activities of antioxidant enzymes were determined under salinity stress. Growth parameters indicated the superiority of cv. Florispan to cv. Gazipasa under milder salinity stress treatment. However, comparative analysis of the two cultivars showed that MDA, H<inf>2</inf>O<inf>2</inf>, ion leakage levels and photosystem II activities were not significantly different, except for the proline activity, which increased only in Florispan leaf tissues under 100 mM salt treatment. Among the processes that govern the tolerance in peanut tissues, proline level and the activity of glutathione reductase (GR) appeared to be only components that play an important part in salt stress protection.