Toxic effects of cadmium, acetochlor and bensulfuron-methyl on nitrogen metabolism and plant growth in rice seedlings

The adverse effects of cadmium (Cd), acetochlor (AC), bensulfuron-methyl (BSM) alone and their coexistence on nitrogen metabolism and plant growth in rice seedlings were studied with aquatic culture experiments. The results demonstrated that in all exposure groups there were marked decrease in the fresh weight of rice seedlings and the activities of nitrate reductase (NR), glutamine synthetase (GS) in the roots and shoots, consequently leading to an increase in free amino acids content and decrease in soluble protein content and nitrate content in the roots and shoots. These results suggested that the toxicity of Cd, AC and BSM to the rice seedlings took place partly through the influence on nitrogen metabolism.