Abstract

Phytoremediation refers to the technologies that use plants to clean up heavy metals and other toxic chemicals from contaminated environments. The main objective of this study was to assay the effects of different concentrations (0, 0.5 and 1.0 g/l) of (ZnCl2) on four cultivars of Indian mustard (Brassica juncea L.) and to determinate the Zn concentration in roots and shoots after 91 days. Significant differences were observed in cultivars and plant parts; this appeared in fresh weight dry weight and plant height. Plant accumulates and antioxidative enzymes under zinc stress were evaluated. Indian mustard effectively generated an antioxidant enzymes defense system at higher zinc rates. Catalase-CAT, peroxidase-POD and superoxide dismutase-SOD were the most indices of zinc-induced oxidative response of Indian mustard plants. The highest accumulation amount of zinc was found in the roots and low in shoots in all cultivars. The highest accumulation (805 mg/kg) of Zn was found in green cultivars. Zinc caused significant change in water content and cell structure in shoots and reduced the maximum cell density and a reduction in the number of spongy cells. All cultivars were able to accumulate and uptake significant amounts of Zn without severe symptoms of phytotoxicity when the metal concentrations were relatively moderate or low.