转Bt基因玉米幼苗残体中Cry1Ab杀虫蛋白田间降解动态

Degradation Dynamics of Cry1Ab Insecticidal Protein Within Transgenic Bacillus thuringiensis Corn Seedling Debris in Field

【目的】研究间苗后留在田间地表的转Bt基因玉米幼苗残体中Cry1Ab杀虫蛋白的降解规律,比较两种Bt玉米幼苗残体中Cry1Ab杀虫蛋白的降解速度。【方法】以两种表达Cry1Ab杀虫蛋白的转Bt基因抗虫玉米MON810和Bt11为材料,采用ELISA方法测定各取样时期中幼苗残体中Cry1Ab杀虫蛋白残留量。【结果】转Bt基因玉米幼苗残体中杀虫蛋白降解是逐渐的,且降解速度较快,到50d时幼苗残体已经完全腐烂,Bt11幼苗残体中的杀虫蛋白已经完全降解,在MON810中还能检测到微量的杀虫蛋白。两种转基因玉米幼苗残体中的Bt杀虫蛋白的初始含量差异不显著,但在同一时间段的Bt杀虫蛋白降解速度存在差异均显著,在30d前MON810幼苗残体中Bt杀虫蛋白降解速度比Bt11降解的快,30d后,则降解趋势相反,到50d取样结束时MON810和Bt11分别降解了初始含量的99.81%和100%。【结论】两种转Bt基因玉米间苗后留在田间的幼苗残体中的Cry1Ab杀虫蛋白降解速度不同,在50d完全腐烂时,其中的杀虫蛋白完全降解或仅有微量残留。

【Objective】The degradation dynamics of Cry1Ab insecticidal protein within transgenic Bacillus thuringiensis corn seedling debris of materials MON810 and Bt11 in field were investigated and compared.【Method】The levels of Cry1Ab protein expression in two transgenic Bt corn seedling debris of materials MON810 and Bt11 were quantified by using enzyme-linked immunosorbent essay （ELISA）.【Result】The results showed that the degradation of Cry1Ab toxin in transgenic corn seedlings was gradual and degraded rapidly. The Cry1Ab insecticidal protein in Bt11 corn seedling debris could not be detected, but small amount of Cry1Ab toxin in MON810 could still be detected when the corn seedling decayed completely 50 days after picked off. The speed of degradation was significantly different in the same period of time between the two materials. The Cry1Ab insecticidal protein in corn seedling debris of materials Bt11 was slower than that in MON810 within the 30 days, but faster than that in MON810 after 30 days. 【Conclusion】 The Cry1Ab insecticidal protein in seedling debris of materials MON810 and Bt11 decreased to 99.81% and 100% of the initial amount at 50 d, respectively.