不同类型土壤中CP4 - EPSPS基因的降解规律及对环境影响的研究

Study on the Degradation Law of CP4-EPSPS gene in Different Types of Soil and its Environmental Impact

以转CP4-EPSPS基因玉米CC-2叶片为试验材料,将叶片研磨成粉末,后分别混入取自吉林公主岭、北京上庄、山东济南、河南新乡的四种土壤中。放入25℃的培养箱中,按期取样,测定各个取样时期土壤中CP4-EPSPS的蛋白残留量,建立降解模型,获得蛋白50%降解天数(DT50)及90%降解天数(DT90)。结果表明,不同地点土壤中的CP4-EPSPS蛋白均呈前期快速降解后期缓慢降解并逐渐趋于稳定的趋势;吉林公主岭、北京上庄、山东济南、河南新乡的DT50分别为1.68 d、1.88 d、1.95 d、2.38 d,DT90分别为5.79 d、5.84 d、6.54 d、7.44 d;四种土壤理化性质检测结果中CP4-EPSPS蛋白在土壤中的降解速度和土壤成分有机质和有效磷含量呈正相关。明确该转基因抗除草剂作物中外源蛋白在不同类型土壤中的降解规律,为下一步田间试验建立降解模型,比较室内及田间降解规律异同奠定基础,以期为转CP4-EPSPS基因抗除草剂玉米释放田间后可能引起的生态环境风险研究提供初步科学依据。

The leaves of transgenic maize cc-2 with cp4-epsps gene were ground into powder and then mixed with four kinds of soil from Gongzhuling(Jilin),Shangzhuang(Beijing),Jinan(Shandong)and Xinxiang(Henan).Put them in a 25℃incubator,take samples regularly,determine the protein residues of CP4-EPSPS in the soil during each sampling period,establish a degradation model,and obtain 50%protein degradation days(DT50)and 90%degradation days(DT90).The results showed that the CP4-EPSPS protein in the soil of different locations showed a trend of rapid degradation in the early stage and slow degradation in the late stage and gradually stabilized;The DT50 of Gongzhuling(Jilin),Shangzhuang(Beijing),Jinan(Shandong)and Xinxiang(Henan)were 1.68 d,2.38 d,1.88 d,and 1.95 d respectively,and the DT90 were 5.79 d,7.44 d,5.84 d,and 6.54 d respectively;Four kinds of soil properties and the degradation rate of the detection result of soil organic matter and phosphorus components CP4-EPSPS protein content in the soil is positively correlated.Clarify the degradation rules of foreign proteins in the genetically modified herbicide-resistant crops in different types of soils,establish a degradation model for the next field test,and compare the similarities and differences of indoor and field degradation rules,and provide a preliminary scientific basis.Provide preliminary scientific basis for the ecological environmental risks that may arise after the release of the field in order to turn CP4-EPSPS gene herbicide-resistant corn.