Response of enzymatic and non-enzymatic antioxidant systems in Excoecaria agallocha to salt stress

Abstract

The effect of NaCl stress on antioxidant enzymes activities was investigated in the leaves of Excoecaria agallocha. Plants were subjected to different levels of NaCl. 100 to 1000 mM. Above 500 mM these mangrove seedlings did not survive. The leaves of 60 day old plants were used for the analysis of enzyme activities. Parameters of enzymatic and non enzymatic antioxidants such as catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), polyphenol oxidase (PPO), superoxide dismutase (SOD), ascorbic acid (ASA) and alpha tocopherol were determined. The highest CAT, POD, APX, PPO and SOD activities in the leaf and root enhanced gradually up to 300 mM of NaCl, the highest ASA and tocopherol activities in the leaf and root were observed at 500 mM of NaCl. These data suggest that the capacity to limit oxidative damage is important for the salt tolerance of E. agallocha.