Effects of 1-butyl-3-methylimidazolium chloride ionic liquid on the growth of rice seedlings

The effects of ionic liquid 1-butyl-3-methylimidazolium chloride ([HMIM]Cl) at the concentrations of 0, 10, 20, 40, 80, 100, 120, 200 mg/L on the length of stem and root of rice seedlings were studied. The activity of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and the content of malondialdehyde (MDA) (exposed for 4 d) were determined with different concentrations of [HMIM]Cl (0, 20, 40, 100 mg/L). The results showed that the inhibition rate on the root was higher than that of stem, indicating that rice root was more sensitive to ionic liquid than the rice stem. The length of stem and root were reduced with the increase of the concentration, and the root was damaged more seriously. SOD, POD, CAT activity of root seedlings were lower than the control with significant difference except for 20 mg/L treatment, which CAT activity was slightly activated. In addition, [HMIM]Cl led to the increase of MDA content, the highest was 155.9% of the control. [HMIM]Cl may increase lipid peroxidation in rice roots.