Accumulation of heavy metals and its biochemical responses in Salicornia brachiata, an extreme halophyte

Abstract

Salicornia brachiata (Amaranthaceae) plants were treated with three different heavy metals, CdCl2·H2O, NiCl2·6H2O and NaAsO2, in the presence of 200 mM NaCl to study their role in metal tolerance. The plants could tolerate up to 300 µM Cd2+, 200 µM Ni2 + and 100 µM As3 +. There was no significant difference in plant fresh weight. All the treatments adversely affected the chlorophyll content of the treated plants. Accumulation of Cd2+, Ni2+ and As3 + in foliar tissue was found to be significantly higher in all the treatments. Proline content was increased significantly in all the treatments except in 50 µM Cd2+. H2O2 content showed gradual increase with the increasing metal concentrations. The catalase (CAT) activity was significantly increased following exposure to all three metals, whereas superoxide dismutase (SOD) activity was significantly higher at maximum concentration of Cd2 + and Ni2 + treatments. This study suggests that Salicornia plants can be a good source for the phytoremediation of heavy metal polluted saline coastal areas.