study the effects of cdcl2 on lipid peroxidation and antioxidant compounds content in brassica napus

heavy metal accumulation in plants causes induction of oxidative stress. plants have severaldefense 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) ascdcl2. after 3 weeks we measured malondealdehyde (mda) content in leaves of treated plants as anindication of lipid peroxidation. we also measured ascorbate (asc) and anthocyanin content asantioxidative compounds. our results showed that a high concentration of cd2+ causes an increase inmda content in leaves compared with control, which is possibly due to the induction of oxidative stressand lipid peroxidation. low levels of this ion cause an increase in asc content, while highconcentrations of this ion cause a decrease in ascorbate content. it is possible that the entrance of asubstrate for asc reduction in the pathway for phytochelatin synthesis will be the cause. anthocyanincontent increased significantly in plants treated with a high concentration of cd2+. increase inanthocyanin content may be an important mechanism for reduction of cadmium toxicity, either byremoving free radicals or compartmentation of cd2+ in vacuole.