NaCl enhances thylakoid-bound SOD activity in the leaves of C3 halophyte Suaeda salsa L.

The halophyte Suaeda salsa L., exposed to different NaCl concentrations, was used to study effect of NaCl salinity on superoxide dismutase (SOD) activities. The fresh weight of plants was markedly enhanced and leaf net photosynthesis rate was not reduced by high NaCl treatment indicating that S. salsa possesses an effective antioxidative response system avoiding oxidative damage. The SOD activity and the proportion of chloroplast SOD increased with the increase of salt concentration or with time. Activity of thylakoid-bound SOD constituted the major part of total chloroplast SOD activity. Results in this study suggest that SOD in chloroplasts of S. salsa, especially the thylakoid-bound SOD which scavenges O-2(.-) radicals in situ, plays an important role in the resistance to oxidative stress induced by high-salinity. (C) 2004 Elsevier Ireland Ltd. All rights reserved.