转基因棉对棉铃虫幼虫生长及中肠蛋白酶活性的影响

室内测定了转慈姑蛋白酶抑制素(API)基因棉对棉铃虫幼虫的抗虫活性及对中肠蛋白酶活性的影响。结果表明，以转基因棉饲养棉铃虫，对幼虫拒食率24h达76．49％，72h达80．57％，试虫体重在取食48h后显著下降，72h后较对照低54．04％。试虫取食转API基因棉后，中肠的强碱性胰蛋白酶和类胰凝乳蛋白酶活性显著降低，取食24、48h后的强碱性胰蛋白酶酶活性分别只有对照组的68．1l％和55．89％；类胰蛋白酶活性分别为对照组的85．87％和64．61％；对弱碱性类胰蛋白酶活性不明显。显示转API基因棉对棉铃虫幼虫中肠蛋白酶的抑制作用与对棉铃虫生长发育的阻滞有良好的相关性。

Influence of API-transgenic cotton plants on growth and midgut proteases activity to Helicoverpa armigera larvae

Influence on the growth and activity of midgut protease of cotton bollworm, Helicoverpa armigera, larvae after fed with API-transgenic cotton plants were determined in the lab. Results showed that the feeding and the growth rate were greatly repressed. The anti-feeding rate was 76.49% after 24 h feeding and 80.57% after 48 h, respectively. The mean body weight of cotton bollworm larvae was also greatly decreased after fed with transgenic cotton leaves. The mean body weight of the larvae 72 h after feeding was 54.04% lower than that of CK. After the insects fed with the API-transgenic cotton plants, the activity of high alkaline trypsin-like enzyme and chymotrypsin-like enzyme was also decreased. The activities of the two enzymes after 24 h feeding was about 68.11 % and 85.89% that of control, respectively. And after 48 h feeding, the activities of the two enzymes were about 55.87 % and 64.61 % that of control, respectively. But no significant influence on the activity of low alkaline trypsin-like enzyme was observed during the whole period. The average body weight of cotton bollworm larvae was greatly decreased 48 h after feeding on the API-transgenic cotton plants. The decrease on the activities of the midgut digest proteases showed good correlation with the retardation on the growth of the larvae fed with API-transgenic cotton leaves.