Response of rice inbred lines to cadmium exposure

The response of a group of rice (Oryza sativa L.) genotypes to cadmium (Cd) exposure was tested using root growth as a parameter over the duration of the treatment. Three distinct response patterns were identified: a significant initial (0.01 mM) dosage effect, which was maintained with the increase of CdCl2 concentration to 1 mM; a significant initial effect, which was intensified with the increase of CdCl2 concentration, resistant to the CdCl2 concentration tested shown by a group of varieties. Significant interactions between dosage and varieties were observed. Enzymatic assays for catalase and glutathione reductase were also carried out in plants exposed to CdCl2, Similar response patterns for both enzymes were observed. The activities of catalase and glutathione reductase in leaves and roots were increased, and in the case of glutathione reductase in roots, such an increase was highly significant, suggesting that the synthesis of reduced glutathione may be stimulated for subsequent synthesis of phyto-chelatins or to dismutate the reactive oxygen species produced by the induced Cd stress.