Studies On The Endogenous Substance That Intake The Degradation Of Acephate In Tomato-Plant

Acephate is a pesticide of low toxicity in systemic insecticide, with stomach poison, tag, and fumigation action, which is widely used in vegetables, tea, tobacco, fruit trees, cotton, rice, wheat, rape and other crops,it can prevent the detriment from a variety of chewing and sucking mouthparts pests,spider mites and health pests.Many literatures have shown that methamidophos is a kind of acephate’s metabolites in plants.Methamidophos is part of high toxic pesticides, that ia harmful to human body and environment.In order to get a further understanding of acephate metabolism in the plants, We explored the influence of different materials in the tomato plants to the hydrolysis of acephate, find that the trigonelline in plants have a acceleration of acephate hydrolysis, and reseached the metabolic product in the process of acephate metabolism.The main results summarized as following:(1)With the result of the basic influence of microbes, enzymes and common alkaloids such three different material in the tomato plant to acephate degradation in water, we confirmed that the trigonelline is one of the factors which can prompt acephate degradation in plants. We have discussed the roots of endophytes and stem endophytic bacteria act on the degradation of acephate in the water, the influence of results showed that the endophytes of root and stem almost have no effect on the degradation of acephate in water;The experiment were also studied peroxidase, catalase, polyphenol oxidase and superoxide dismutase in plants influence on acephate degradation, results showed that the four common enzyme has no effect on the degradation of acephate as well;Finally proped the situation with tomatine and trigonelline to acephate degradation,with the adding of trigonelline experiment, acephate degradation rate is significantly higher than the speed of degradation in the water, while the other one have no effect on the degradation.(2)Through the comparison of different extraction methods, residue analysis methods were established for the trigonelline in tomato plant roots, stems, leaves and fruit: extract with methanol soak through overnight, after 0.22 um membrane purification,with column of ZORBAX-NH2 separation, analysis of high performance liquid chromatography (HPLC) - Shimadzu LC - 20. The minimum detectable concentration of trigonelline in the above samples is 0.1 mg/kg by this analysis method,;The average recovery is between 74.1%～107.6%, relative standard deviation is 0.3%～13.2%;From the experimental data and results of recovery rate, we find the method is simple and convenient, purification effect is nice, good parallelism, precision and sensitivity also is high.(3)The stability of trigonelline in aqueous solution was studied, the results have showed that the concentration of 1 mg/kg of trigonelline in 0 d,5 d,10 d and 15 d was detected 1.01 mg/kg,1.02mg/kg,1.05 mg/kg and 1.04 mg/kg, the relative standard deviation is 1.66%～3.33%,which proved trigonelline is stable in aqueous solution.Compared to the influence of different concentrations trigonelline act on acephate degradation in pure water and nutrient solution, learned that with the increase of the concentration of the trigonelline, the rate of acephate degradation is greater.In pure water experiments, the degradation of the acephate is 25.66% in the control group in 240h, and the degradation when adding three concentration 5 mg/kg, 50mg/kg and 500mg/kg trigonelline respectively is 34.31%、35.59% and 48.58%;in nutrient solution experiments the degradation of the acephate in the control group is 21.18%after 240h, and the result with adding six kinds of concentration 1 mg/kg、 5mg/kg、10mg/kg、50mg/kg、100mg/kg and 500mg/kg trigonelline in degradation is 26.11%、28.30%、30.20%、31.16%、37.25% and 47.74% respectively.The time that could detected methamidophos was 72h and 96h relate to two groups of experiments, 9.63ug/kg methamidophos is formed in 240h in pure water control group, and the experiment in adding three different concentrations respectively produced trigonelline 10.98ug/kg、13.83ug/kg and 34.51ug/kg;8.42ug/kg methamidophos was detected in 240h in nutrient solution control group, and the content respectively is 8.76ug/kg、 9.46ug/kg、9.88ug/kg、11.76ug/kg、22.66ug/kg and 30.31ug/kg when adding three different concentrations of trigonelline in 240h.(4)Methamidophos as the research object, made a comparison about determination results which three different concentrations 5 mg/kg、50 mg/kg and 500 mg/kg impact on methamidophos degradation in the pure water,we determined that the trigonelline also have influence on the degradation of methamidophos.In the control experiment, methamidophos degraded abou 10.64% in water after 240h, and methamidophos in the experiments with adding 5 mg/kg and 50 mg/kg of trigonelline respectively degraded 20.54%、25.01%, the adding 500 mg/kg trigonelline of experiment, the degradation of methamidophos almost was 33.36%.