Oxidative Toxicity Of Glyphosate On Misgurnus Anguillicadatus

Glyphosate is an organophosphorus endophytic herbicide with remarkable herbicidal efficacy.It is easily absorbed by plant leaves and transmitted to the whole plant.Glyphosate has high activity to annual and perennial weeds.Because of its broad spectrum,high efficiency and low cost,it has become the most widely used organophosphorus herbicide in the world.However,some studies have found that it has some potential hazards to the environment and human health.As a common freshwater fish,Misgurnus anguillicaudatus is sensitive to water environmental pollutants.In this paper,the acute toxicity and oxidative toxicity of organophosphorus pesticide glyphosate to Misgurnus anguillicaudatus were studied by semi-hydrostatic experiment and enzyme detection.The aim was to provide theoretical basis for the detection of toxic effects of glyphosate on fish and the monitoring and evaluation of water pollution.The main results are as follows:1.Acute toxic effects of glyphosate on Misgurnus anguillicaudatusThe acute toxicity of glyphosate to Misgurnus anguillicaudatus was studied by semi-static water experiment.It was found that glyphosate had obvious acute toxicity to Misgurnus anguillicaudatus.The semi-lethal concentration of glyphosate to loach at 24 h,48 h,72 h and 96 h were 1070 mg·L^-1,950 mg·L^-1,776 mg·L^-1,707 mg·L^-1,and the safe concentration of SC was 230 mg·L^-1,toxicity to fish is moderately toxic.2.Oxidative toxicity of glyphosate on Misgurnus anguillicaudatusThe effects of glyphosate on the activities of superoxide dismutase?SOD?,catalase?CAT?,peroxidase?POD?in the liver of loach were studied.The results showed that with the increase of glyphosate concentration,the activities of SOD and POD increased at first and then decreased.POD activity reached at 31 mg·L^-1 concentration in each treatment group.The activity of SOD reached the highest value when the concentration of glyphosate was 56 mg·L^-1.With the prolongation of exposure time,the activity of SOD and POD increased at first and then decreased.The activity of SOD was the highest in the medium and low concentration treatment group at 21 days,and the highest in the high concentration treatment group at 14 days.The activity of POD was the highest in the glyphosate concentration(17 mg·L^-1,31 mg·L^-1)at 21 days.At glyphosate concentration(56 mg·L^-1,100 mg·L^-1),POD activity was the highest at 14 days,and at 7 days of glyphosate exposure,CAT activity in each treatment group was lower than that in the control group.With the prolongation of exposure time,CAT activity showed a trend of"inhibition-Induction-inhibition".Glyphosate has obvious oxidative toxicity to loach,causing oxidative damage to the body.3.Effects of Glyphosate on GSSG Content in Liver of Misgurnus anguillicaudatusThe effects of glyphosate on oxidized glutathione?GSSG?content in Misgurnus anguillicaudatus were studied.It was found that with the increase of glyphosate concentration at the same time,the GSSG content first increased and then decreased.The highest GSSG content was found in 31 mg·L^-1 treatment group.At the same concentration,the same GSSG content was found with the prolongation of exposure time.The content of GSSG was the highest at 21 days,and the highest at 31 mg·L^-1,3.53 umol·L^-1.The results showed that glyphosate exposure could induce lipid peroxidation of cell membrane to form GSSG,and glyphosate had obvious oxidative toxicity to Misgurnus anguillicaudatus.