Abstract

The remediation of heavy metal-contaminated sites using plants presents a promising alternative to current methodologies. In this study, the potential of Colocassia esculentum for Nickel (Ni) accumulation was determined. C. esculentum plants exposed to Ni, demonstrated capability to accumulate on average, more in shoots as compared to roots, suggesting better translocation of Ni from root to shoot. High metal content in soil caused reduction in growth parameters and an increase in oxidative stress. Under heavy metal stress, an increase in catalase, peroxidase, ascorbic acid and proline were observed in the roots along with some anatomical changes. Lipid peroxidation showed a slight increase by Ni treatment along with some anatomical changes in the root. This work demonstrates that metal induced oxidative stress occurs by the presence of heavy metals at higher concentrations. It also suggests that superior antioxidative defenses, particularly catalase activity, may play an important role in C. esculentum. The outcome of this study corroborate that C. esculentum is a suitable candidate for the phytoremediation of Ni contaminated soil and could be considered as a potential Ni hyperaccumulator plant species.

Key words: Colocassia esculentum, heavy metal, nickel, oxidative stress, tolerance.