转基因玉米Bt蛋白降解规律及其与土壤动物互作研究

以转Cry11Ac基因玉米及其非转基因对照为试验材料,利用大、中、小不同孔径的凋落物分解袋,研究黑土区转基因玉米外源基因表达Bt蛋白的降解规律及其与土壤动物的互作关系。结果表明,第二年春天大孔径凋落物分解袋内转基因玉米残体Bt蛋白含量为初始含量的25.98%,至8月份Bt蛋白只剩下初始含量的0.35%。分解袋孔径对转基因玉米及其对照玉米凋落物分解率和Bt蛋白降解率均有显著影响,表现为大孔径中孔径小孔径,说明大型和中型土壤动物都可以促进凋落物分解和Bt蛋白的降解。与对照玉米相比,转基因玉米凋落物分解率和凋落物内土壤动物群落结构参数都没有显著差异(P0.05,t-test),说明导入Bt基因对玉米残体分解速率和土壤动物均无显著影响。

Research on Bt Protein Degradation and Its Interaction with Soil Fauna

In this study, using genetically modified (GM) maize hybrid with Cry1Ac gene (Bt-799) and its corresponding non-GM material (Zheng 58), Bt protein degradation and its interaction with soil fauna were studied by litter decomposition bags with different mesh-sizes (large, medium and small aperture). Results showed that Bt protein content in the litter decomposition bag with large apertures was reduced to 25.98% of the original content in the next spring, and reduced to only 0.35% in the next summer (August). In addition, litter decomposition and Bt protein degradation rates were related with mesh size, and the larger the mesh size was, the higher the rate would be, which indicated that the large-and middle-size soil fauna played important roles in litter decomposition and Bt protein degradation. While, the litter decomposition rates for Bt-799 and Zheng 58 was not different significantly in responding to soil fauna community composition and community structure parameters (P>0.05, t-test), indicating that the import of Bt gene had no effect on the litter decomposition and soil fauna in soil.