Toxicological Effects Of Atrazine On Lemna Minor And Its Degradation

Atrazine is a herbicide used largely all over the world. It has relatively high solubility in water and low degradability in the environment, which allows it readily enter aquatic environment and poses threat on aquatic ecosystems. So the aquatic toxicological studies about the uptake, bioaccumulation, effects and biodegradation of atrazine in aquatic organisms are important for the management. This research was carried out to investigate:(1) the effects of atrazine on the growth and photosynthesis of aquatic plant lemna minor,(2) the responses of antioxidant and detoxification enzymes in lemna minor to atrazine;(3) the bioaccumulation and degradation of atrazine by the aquatic angiosperm lemna minor. Futhermore, an analytical method for determining residues of atrazine in water and plants by HPLC was established.The results showed that atrazine can pose harmful effects on the macrophyte. And the growth of lemna minor and the content of chlorophyll a/b showed negative relationship with the concentration of atrazine. Futhermore, the peroxidase activity of lemna minor was enhanced in range of 0~100 u g/L and inhibited in range of 100~500ug/L. In contrast, the activities of antioxidant enzymes(superoxide dismutase, catalase, glutathione-S-transferase)showed positive relationship with the increase of the concentration of atrazine.The aquatic plant lemna minor showed ability to remove and metabolize atrazine. At 10 mg/L of the initial concentration of atrazine,5% of the atrazine was removed and 3.75% was degraded by the duckweed.