Cd uptake in rice cultivars treated with organic acids and EDTA.

A pot experiment was conducted to examine the activity of antioxidant enzymes, the content of malondialdehyde (MDA), proline and protein, and Cd uptake in different rice cultivars exposed to Cd (0, 1 and 5 mg/kg) in the presence of organic acids and ethylenediamine tetraacetic acid (EDTA). The results showed the increase in activity of dismutase (SOD), contents of proline and protein but a decline in activities of peroxidase (POD) and catalase (CAT), and MDA content for cultivars Xiushui63 and IIyou527. The resistance to Cd was higher in Xiushui63 than that in Iyou527 under the same Cd treatment. Cadmium contents in grain, straw and roots of both cultivars were markedly reduced in the presence of organic acids and EDTA. Grain Cd contents was the highest for plants treated with organic acids, followed by organic acids + 1/2EDTA, and the lowest with EDTA; Cd contents in straw and root were the lowest for plants treated with organic acids, followed by organic acids + 1/2EDTA, and the highest with EDTA treatment when exposed to Cd.