摘要
The leaves of Bt (Bacillus thuringiensis) transgenic poplar (Populus nigra L.) and CpTI (Cowpea trypsin inhibitor) transgenic poplar ((P. tomentosa×P. bolleana)×P. Tomentosa) were taken to feed the 4th-5th-instar larvae of American white moth (Hyphantria cunea (Drury)) for determination of the activities of the protective enzyme system inside larvae’s body. The physiological and biochemical effects of the transgenic poplars on the larvae were studied. The results showed that the two kinds of transgenic poplars had similar effects on the protective enzyme system in the midgut of larvae. The activities of superoxide dismutase, catalase, and peroxidase in midgut of the larvae increased gradually, reached the highest value at a certain time, and then decreased suddenly. For the larvae that were fed with the leaves of Bt transgenic poplar, the peak value of superoxide dismutase and catalase presented at the time of 24-h feeding, while the peak of peroxidase took place at the time of 12-h feeding. The activities of these protective enzymes for the larvae that were fed with leaves of CpTI transgenic poplar peaked 12 h later than that of those fed with leaves of Bt transgenic poplar. The comparison of activities of the protective enzymes was also carried out between the larvae with different levels of intoxication. It was found that the activities of protective enzyme of the seriously intoxicant larvae were higher than that of the lightly intoxicant larvae. This difference was more obvious in the group treated with CpTI transgenic poplar.
以转Bt基因欧洲黑杨(P.nigra L.)和转CpTI基因毛白杨(Populus tomentosa)叶片饲喂4-5龄美国白蛾（Hyphantria cunea Drury）幼虫，对其体内保护酶系统活性进行测定。结果表明，饲喂两种转基因杨树叶片的幼虫中肠保护酶表现出相似的变化规律，SOD、CAT和POD三种酶的活性在饲喂后数小时内逐渐增加，某一时刻达到最高值，此后突然下降。饲喂转Bt基因杨树叶片的幼虫，其中肠SOD、CAT活性峰值出现在饲喂后的24小时，POD活性峰值出现在饲喂后的12小时；饲喂转CpTI基因杨树叶片的幼虫，其中肠三种保护酶活性高峰出现时间均较前者滞后12小时。本文还比较了饲喂两种转基因叶片不同中毒程度的美国白蛾幼虫体内保护酶活性，发现不论饲喂那种转基因叶片，中毒较轻者其体内保护酶活性显著高于中毒较重者，这种差异在饲喂CpTI叶片的处理株表现尤为明显。
基金
the China Postdoctoral Research Foundation.
