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 Ni^{2 +} and 100 µM As^{3 +}. 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 As^{3 +} 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 Cd^{2 +} and Ni^{2 +} treatments. This study suggests that Salicornia plants can be a good source for the phytoremediation of heavy metal polluted saline coastal areas.

Keywords:

• Antioxidants
• halophytes
• metal contamination
• phytoremediation
• Salicornia brachiata

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Acknowledgements

The authors are thankful to CSIR, New Delhi (NWP-020) and GSBTM, DST, Govt. of Gujarat, India for financial assistance and support. The authors are thankful to Dr A.K. Parida for suggestions improving the manuscript.

Notes

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark