Chromium-induced modulation in the antioxidant defense system during phenological growth stages of Indian mustard.

Chromium-induced modulation in the enzymes and metabolites of antioxidants was investigated at various phenological stages of Indian mustard (Brassica juncea (L.) Czern. & Coss. cv Pusa Jai Kisan)], grown with various levels of chromium (Cr) in pots under natural environmental conditions. Chromium accumulation in the root, stem and leaves increased with the advancement in the age of the plants. Growth of Indian mustard was not affected significantly by the supply of Cr up to the levels of 400 mg kg(-1) soil. Activities of superoxide dismutase (SOD), ascorbate peroxide (APX), catalase (CAT), and glutathione reductase (GR) increased in the leaves of Cr-treated plants, when compared with control. High activities of antioxidant enzymes supported by high Cr concentrations in roots and aerial parts (except seeds) established the Indian mustard as a potential hyperaccumulator anda hypertolerant species to Cr stress. For this study, an edible crop was chosen intentionally so as to tap maximum benefit by remediating the contaminated site on one hand and getting uncontaminated seeds to raise the next generation, on the other.