Response of antioxidant systems to NaCl stress in the halophyte Cakile maritima

The effects of salt stress on antioxidative activities were investigated in a coastal halophyte, Cakile maritima. Two Tunisian accessions, Jerba and Tabarka, were compared. Plants were subjected to 100, 200, or 400 mM NaCl for 20 days. Parameters of oxidative stress [malondialdehyde (MDA), electrolyte leakage (EL), and hydrogen peroxide (H2O2) concentration], activities of several enzymes [superoxide dismutase (SOD), catalase (CAT), peroxydase (POD), ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), and glutathione reductase (GR)], and antioxidant molecules (ascorbate, ASC, and glutathione, GSH) were determined. Growth of Jerba plants was improved at 100 mM NaCl as compared to that of control. Tabarka growth was inhibited by salt at all NaCl concentrations. The relative salt tolerance of Jerba was associated with high antioxidant enzyme activities and glutathione content, together with low MDA content, EL, and H2O2 concentration. Lower antioxidant activities and higher MDA content, EL, and H2O2 concentration were found in Tabarka. As a whole, these data suggest that the capacity to limit oxidative damage is important for salt tolerance of C. maritima.