Research Of The Absorption And Degradation And Mechanism Of The Metabolism Of Acephate In Solanum Lycopersicum Leaf

This study take acephate as the research object,the solanum lycopersicum plants of this experiment are cultivated by hydroponic method,and the study purpose is to measure the effect of live or dead、light、leaf stage to the acephate degradation in solanum lycopersicum leaf and the metabolism of increasing toxicity.In order to research the mechanism of the metabolism of increasing toxicity after finding obvious phenomenon,research IP team entrust Beijing Novogene biological information technology Co.,LTD to preside over the project of solanum lycopersicum leaf the transcriptome sequencing experiments.In the report of Beijing Novogene biological information technology co.,LTD,many relevant pathways,genes and enzymes are founded.And research IP team also entrust Shanghai Generay biotech Co.,LTD to preside over the q RT-PCR project to verify the results of the transcriptome sequencing experiments,and everything is OK.Results are summarized as follows:（1）Soaking the leaf whose leaf stage is 20-day in acephate’s pure water solution whose concentration are 300 mg·kg（-1） and 1000 mg·kg（-1） for 30 seconds,and cultivating these solanum lycopersicum plant for 168 hours.Setting the leaf which is soaked in methamidophos pure water solution whose concentration is 40 mg·kg（-1） as the control group.The higher the concentration of acephate,the higher the concentration of methamidophos.When the concentration of acephate is 300 mg·kg（-1）,methamidophos’ s concentration in the experimental samples which are cultivated for 168 hours is 4.48 mg·kg（-1）.When the concentration of acephate is 1000 mg·kg（-1）,methamidophos’ s concentration in the experimental samples which are cultivated for 168 hours is 31.07 mg·kg（-1）.The result shows that the phenomenon of metabolism of acephate for methamidophos in solanum lycopersicum leaf is a general result.（2）Soaking the leaf whose leaf stage is 20-day in acephate’s pure water solution whose concentration is 300 mg·kg（-1）,and cultivating these solanum lycopersicum plant in dark and light environment conditions for 120 hours.It is observed that the methamidophos generation and accumulation of 0-24 h is far more than 24-48 h and 48-72 h.In light environment conditions,0-24 h’s methamidophos accumulation rate is 4.05 mg·kg（-1）·24h^-1,24-48 h’s methamidophos accumulation rate is 0.38 mg·kg（-1）·24h^-1,48-72 h’s methamidophos accumulation rate is 0.11 mg·kg（-1）·24h^-1;In dark environment conditions,0-24h’s methamidophos accumulation rate is 3.74 mg·kg（-1）·24h^-1,24-48 h’s methamidophos accumulation rate is 1.03mg·kg（-1）·24h^-1,48-72 h’s methamidophos accumulation rate is 0.47 mg·kg（-1）·24h^-1.The result shows that the accumulation of light and dark environment conditions are almost same,so metabolism of acephate for methamidophos in solanum lycopersicum leaf has nothing to do with the abiotic factors,this is due to the role of biological factors generated conversion reaction.（3）Soaking the detached leaf whose leaf stage is 20-day in acephate’s pure water solution whose concentration is 1000 mg·kg（-1）,and inserting the detached leaf in plastic pipes which are filled up with Hoagland nutrient solution to keep the detached leaf fresh.It can be seen from the results that acephate can be degraded in the live leaf and it can be degraded in detached leaf,too.The original pesticide residues concentration in solanum lycopersicum live and detached leaf of acephate are 422.53 mg·kg（-1）,and the acephate’s pesticide residues concentration changes to 110 mg·kg（-1） after cultivating live and detached leaf for 168 hours,so the degradation of acephate in solanum lycopersicum live and detached leaf are almost the same.But the concentration of the resultant-methamidophos are different in solanum lycopersicum live and detached leaf.When the cultivation time is 14 hours,the concentration of the methamidophos is 27.67 mg·kg（-1） in solanum lycopersicum live leaf,but 1.66 mg·kg（-1） in the detached leaf.When the cultivation time is 168 hours,the concentration of the methamidophos is 31.07 mg·kg（-1） in solanum lycopersicum live leaf,but 6.50 mg·kg（-1） in the detached leaf.This suggests that there are many differences between complete nutrition conditions and uncomplete nutrition conditions solanum lycopersicum leaf when comes to degradating and metabolizing acephate.Solanum lycopersicum is a hydroponic plants,soil cultivation plants and cutting plants,and they leaf will not be dead when the leaf of this kind of plant is detached from stems,but will accelerate aging.The metabolism of aging leaf will be weaker and weaker,and so do the detached leaf.This experiment further illustrated that metabolism of acephate for methamidophos in solanum lycopersicum leaf has nothing to do with the abiotic factors,this is due to the role of biological factors generated conversion reaction.（4）Soaking the detached leaf whose leaf stage are 20-day and 30-day in acephate’s pure water solution whose concentration is 1000 mg·kg（-1）.The original pesticide residues concentration in solanum lycopersicum leaf of acephate are 978.40 mg·kg（-1） in 30-day leaf and 382.50 mg·kg（-1） in 20-day.The 0-24 h’s acephate degradation rate of 30-day leaf is 301.98 mg·kg（-1）·24h^-1 and 20-day leaf is 139.9 mg·kg（-1）·24h^-1.The total degradation concentration amount of acephate are 534.23mg·kg（-1） in 30-day leaf and 272.83 mg·kg（-1） in 20-day leaf when the cultivation time is 168 hours.The 0-24h’s methamidophos accumulation rate of 30-day leaf is 9.10 mg·kg（-1）·24h^-1 and 20-day leaf is 28.67 mg·kg（-1）·24h^-1.The total accumulation concentration amount of methamidophos are 17.86 mg·kg（-1） in 30-day leaf and 31.06 mg·kg（-1） in 20-day leaf.Obviously,the older the leaf is,the lower the conversion efficiency of acephate transfers to methamidophos is.（5）Soaking the detached leaf whose leaf stage are 20-day and 30-day in methamidophos’ s pure water solution whose concentration is 40 mg·kg（-1）.The original pesticide residues concentration in solanum lycopersicum leaf of methamidophos are 34.35 mg·kg（-1） in 30-day leaf and 14.17 mg·kg（-1） in 20-day leaf.The 0-24 h’s methamidophos degradation rate of 30-day leaf is 17.87 mg·kg（-1）·24h^-1 and 20-day leaf is 7.82 mg·kg（-1）·24h^-1.The total degradation concentration amount of acephate are 22.03 mg·kg（-1） in 30-day leaf and 9.92 mg·kg（-1） in 20-day leaf when the cultivation time is 120 h.The experiment also found a new phenomenon:the solanum lycopersicum leaf can metabolize acephate to methamidophos.The accumulation volatility of acephate in solanum lycopersicum leaf whose leaf stage are 20-day and 30-day are rising first and then slow down.The acephate accumulation peak time of solanum lycopersicum leaf whose leaf stage is 30-day is 4h,and the concentration is 6.79 mg·kg（-1）.The acephate accumulation peak time of solanum lycopersicum leaf whose leaf stage is 20-day is 2 hours,and the concentration is 0.093 mg·kg（-1）.So the peak time is 2-4 hours.The degradation intensity of 30-day leaf stage is harder than 20-day leaf stage,so the production of acephate is more than the other,even so,the methamidophos degradation concentration and production concentration of 20-day leaf stage is out of proportion.The original pesticide residues concentration in solanum lycopersicum leaf of methamidophos are 34.35 mg·kg（-1） in 30-day leaf and 14.17 mg·kg（-1） in 20-day.The accumulation peak concentration of acephate are 6.79 mg·kg（-1） in 30-day and 0.093 mg·kg（-1） in 20-day.So the original pesticide residues concentration in solanum lycopersicum leaf whose leaf stage is 30-day of methamidophos is 2.42 times as much as 20-day,but the acephate production of 30-day is 73.01 times as much as 20-day,it is out of proportion.By the experimental results,more research is needed to figure out the difference of the transcriptome in 30-day leaf and 20-day leaf.（6）The results of the GO terms and KEGG predict and identify that so me pathways are important to metabolism of acephate for methamidophos in so lanum lycopersicum leaf,such as Phenylalanine metabolism,Sulfur metabolis m,Cyanoamino acid metabolism,Phenylpropanoid biosynthesis,Pentose and glucur onate interconversions,Pyruvate metabolism,Synthesis and degradation of ketone bodies,and some enzymes in these pathways are important to metabolism of ac ephate for methamidophos in solanum lycopersicum leaf,too.They are Formyltetr ahydrofolate,deformylase,Ureidoglycolate,amidohydrolase,Ceramidase,Amidase,For mamidase,Urease,N-carbamoylputrescine amidase,Beta-ureidopropionase,Malonate-s emialdehyde dehydrogenase,Methylmalonate-semialdehyde dehydrogenase,Pyruvate dehydrogenase,Dihydrolipoamide S-acetyltransferase.