Document Type: Regular Paper
Shahid Bahonar University of Kerman
International Centre of Science, High Technology & Environmental Science
Heavy metal accumulation in plants causes induction of oxidative stress. Plants have several
defense systems involved in detoxifying free radicals. In the present research we treated the 15 d.
seedlings of B. napus grown in pots with different concentrations of cadmium (0, 10, 50 and 100 μM) as
CdCl2. After 3 weeks we measured malondealdehyde (MDA) content in leaves of treated plants as an
indication of lipid peroxidation. We also measured ascorbate (ASC) and anthocyanin content as
antioxidative compounds. Our results showed that a high concentration of Cd2+ causes an increase in
MDA content in leaves compared with control, which is possibly due to the induction of oxidative stress
and lipid peroxidation. Low levels of this ion cause an increase in ASC content, while high
concentrations of this ion cause a decrease in ascorbate content. It is possible that the entrance of a
substrate for ASC reduction in the pathway for phytochelatin synthesis will be the cause. Anthocyanin
content increased significantly in plants treated with a high concentration of Cd2+. Increase in
anthocyanin content may be an important mechanism for reduction of cadmium toxicity, either by
removing free radicals or compartmentation of Cd2+ in vacuole.