Investigation of arsenic accumulation and tolerance potential of Sesuvium portulacastrum (L.) L.

Sesuvium portulacastrum (L.) L., a facultative halophyte, is considered a suitable candidate for the phytoremediation of metals. An investigation of As accumulation and tolerance was conducted in Sesuvium plants upon exposure to As(V) (100-1000 mu M) for 30 d. Plants demonstrated a good growth even after prolonged exposure (30 d) to high As(V) concentrations (1000 mu M) and a significant As accumulation (1551 mu g g(-1) dry weight) with a bioaccumulation factor of more than ten at each concentration. The results of shoot and root dry weight, malondialdehyde accumulation, photosynthetic pigments, and total soluble proteins demonstrated that plants did not experience significant toxicity even at 1000 mu M As(V) after 30 d. However, metabolites (total non-protein thiols and cysteine) and enzymes (serine acetyltransferase, cysteine synthase and gamma-glutamylcysteine synthetase) of thiol metabolism, in general, remained either unaffected or showed slight decline. Hence, plants tolerated high As(V) concentrations without an involvement of thiol metabolism as a major component. Taken together, the results indicate that plants are potential As accumulator and may find application in the re-vegetation of As contaminated sites. (C) 2010 Elsevier Ltd. All rights reserved.