Biochemical responses of two typical duckweeds exposed to dibutyl phthalate

Effect of dibutyl phthalate (DBP) on physiologic and biochemical characteristics of two species of duckweed ( Spirodela polyrhiza and Lemna minor ) from Tai Lake in China was investigated. The results indicated that different degree of poisoning symptoms appeared on duckweeds after 7 days' exposure to different concentrations of DBP. With the increase of DBP concentration, content of chlorophyll and soluble protein decreased sharply, and activity of anti-oxidant enzyme systems including catalase (CAT), superoxide dismutase (SOD) and malondialdehyde (MDA) content increased significantly and decreased afterwards. With the concentration of DBP of 0.5 mg/L and 0.005 mg/L, SOD activity of Spirodela polyrhiza and Lemna minor reached peak value respectively, while CAT activity were maximum under the concentration of 1mg/L and 0.05 mg/L. It could be concluded that DBP can affect the growth of both Spirodela polyrhiza and Lemna minor , and the former has better endurance to exposure than the latter.