Upma Narang, AK Thukral, Renu Bhardwaj and SK Garg
Keywords: Eichhornia crassipes (Mart.) solms, mercury, oxidative stress, MDA, superoxide dismutase, catalase, guaiacol peroxidase and vitamin E.
Abstract: Mercury is rated third after heavy metals like arsenic and lead in the top ten of the priority list as provided by the American Agency for Toxic Substances and Disease Registry. The clean up of Hg requires the removal of this metal. Since Hg is toxic at very low concentrations, its removal from water bodies is not possible with chemical treatment. Phytoremediation can prove to be most effective eco-friendly technique for removal of this heavy metal. Eichhornia crassipes (Mart.) Solms is being used successfully for the phytoremediation of trace elements in natural and constructed wetlands. The present investigation was undertaken to study the role of antioxidative system of E. crassipes cultured in solutions containing mercuric chloride. It was found from the results of present work that malondialdehyde content of the plants increased up to 3.7-fold thereby indicating a high level of Hg stress. It was observed that the plants counteracted this stress by stimulation of the antioxidative enzymes viz. superoxide dismutase (SOD), guaiacol peroxidase (GPX) and catalase (CAT) and molecular antioxidant vitamin E. The activities of these enzymes and antioxidant increased up to 0.8, 3.9, 24.6 and 3.7-fold respectively under Hg stress.
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