Affiliations: State Key Lab of Integrated Management of Pest Insects
and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100080,
China
Abstract: To assess the sublethal toxicity of the herbicide acetochlor to
earthworms and to find out biomarkers possible inducted under acetochlor
exposure, Eiseniafetida was exposed to artificial soils supplemented with
different concentrations of acetochlor (5, 10, 20, 40 and 80 mg/kg soil). Effects
of the acetochlor on cytochrome P450 monooxygenases p-nitroanisole
O-demethylase (ODM), aldrin epoxidase(AE) and glutathione-S-transferases (GSTs)
activities were determined. The results revealed cytochrome P450 monooxygenases
were elevated with increasing concentrations of acetochlor, and the AE activity
increased significantly compared with control at the concentration of 80 mg/kg
(P<0.05). However, ODM activity from E. fetida was not induced
significantly by acetochlor at all treatments (P>0.05). Sodium dodecyl
sulfate-polyacryamide gel electrophoresis(SDS-PAGE) showed that one protein
band was visualized and no evident differences were found in protein profiles
between treatments and control. The GST activity increased significantly with
longer duration (P<0.05) and increasing concentrations of
acetochlor exposure (P<0.05). This study showed that the
monooxygenases and GSTs activities in E. fetida could be induced by acetochlor,
and thus, the AE and GST could be used in sublethal assays for soil
contamination surveys and GST could be used as biomarkers ofacetochlor exposure
in E. fetida.
