Paper Title
Potential of Eichhornia Crassipes (MART.) Solms as a Mercury Phytoremediator

Phytoremediation is a cost effective, environment friendly technology for the reclamation of habitats impregnated with heavy metals. Eichhornia crassipes (Mart.) Solms is an aquatic macrophyte well known for its capacity to accumulate heavy metals viz. Cd, Cu, Mn, Ni, Pb, Eu(III) and Hg. The present study focuses on understanding the mechanism of mercury uptake by E. crassipes, its effects on the antioxidative defence system of the plant and to evaluate the phytoremediation potential of E. crassipes. For different concentrations of mercury treatment given to the plants, the mercury uptake has been observed to follow a dose and time dependent increase. Oxidative stress occurred in E. crassipes plants due to mercury treatment as observed by increase in MDA content with the increase in mercury concentration. To remove the reactive oxygen species generated as a result of mercury exposure, the antioxidative defence system of E. crassipes was triggered and its components interacted in a coordinated way. Despite the increase in MDA content up to 1000 μg l-1, the stimulation of most of the components of antioxidative defence system was limited to 100 μg l-1 concentration. CAT and ascorbic acid played a role in detoxifying the effects of mercury being produced at highest concentration by showing the enhancement up to 1000 μg l-1. The results of the present investigation thus suggest E. crassipes to be an accumulator of mercury that can be used for reclamation of polluted aquatic habitats by periodic removal of the spent plants. Keywords: phytoremediation, antioxidative defence, superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase, DHAR, MDHAR, tocopherol, E. crassipes