以抗生素(四环素和链霉素)处理的食物饲喂贡嘎蝠蛾Hepjalus gonggaensis Fu & Huang,sd.nov.4龄幼虫1个月后,肠道主要消化酶的种类和酶活都发生了显著变化。经测定知,淀粉酶和蛋白酶是4龄幼虫主要的消化酶,其次为海藻糖酶、麦芽糖...以抗生素(四环素和链霉素)处理的食物饲喂贡嘎蝠蛾Hepjalus gonggaensis Fu & Huang,sd.nov.4龄幼虫1个月后,肠道主要消化酶的种类和酶活都发生了显著变化。经测定知,淀粉酶和蛋白酶是4龄幼虫主要的消化酶,其次为海藻糖酶、麦芽糖酶和纤维素酶。经抗生素处理的食物饲喂后,与正常对照相比,抗生素处理的幼虫体重增长百分比显著降低(P<0.01),所测的消化酶酶活比对照也显著降低(P<0.01)。另外,肠道内原有的半纤维素酶和纤维素酶在抗生素处理后没有检测出酶活。据此认为,抗生素可能对幼虫生长有毒害作用。其原因可能是抗生素长期使用导致肠道菌群紊乱,消化生理发生改变,从而导致一些消化酶活性下降甚至完全失去活性。展开更多
Bitter gourd （Momordica charantia L.） seeds contain several squash-type serine proteinase inhibitors （PIs）, which inhibit the digestive proteinases of the polyphagous insect pest Helicoverpa armigera. In the prese...Bitter gourd （Momordica charantia L.） seeds contain several squash-type serine proteinase inhibitors （PIs）, which inhibit the digestive proteinases of the polyphagous insect pest Helicoverpa armigera. In the present work isolation of a DNA sequence encoding the mature peptide of a trypsin inhibitor McTI-Ⅱ, its cloning and expression as a recombinant protein using Pichia pastoris have been reported. Recombinant McTI-Ⅱ inhibited bovine trypsin at 1 ： 1 molar ratio, as expected, but did not inhibit chymotrypsin or elastase. McTI-Ⅱ also strongly inhibited trypsin-like proteinases （81% inhibition） as well as the total proteolytic activity of digestive proteinases （70% inhibition） from the midgut of H. armigera larvae. The insect larvae fed with McTI-Ⅱ-incorporated artificial diet suffered over 70% reduction in the average larval weight after 12 days of feeding. Moreover, ingestion of McTI-Ⅱ resulted in 23% mortality in the larval population. The strong antimetabolic activity of McTI-Ⅱ toward H. armigera indicates its probable use in developing insect tolerance in susceptible plants.展开更多
文摘以抗生素(四环素和链霉素)处理的食物饲喂贡嘎蝠蛾Hepjalus gonggaensis Fu & Huang,sd.nov.4龄幼虫1个月后,肠道主要消化酶的种类和酶活都发生了显著变化。经测定知,淀粉酶和蛋白酶是4龄幼虫主要的消化酶,其次为海藻糖酶、麦芽糖酶和纤维素酶。经抗生素处理的食物饲喂后,与正常对照相比,抗生素处理的幼虫体重增长百分比显著降低(P<0.01),所测的消化酶酶活比对照也显著降低(P<0.01)。另外,肠道内原有的半纤维素酶和纤维素酶在抗生素处理后没有检测出酶活。据此认为,抗生素可能对幼虫生长有毒害作用。其原因可能是抗生素长期使用导致肠道菌群紊乱,消化生理发生改变,从而导致一些消化酶活性下降甚至完全失去活性。
文摘Bitter gourd （Momordica charantia L.） seeds contain several squash-type serine proteinase inhibitors （PIs）, which inhibit the digestive proteinases of the polyphagous insect pest Helicoverpa armigera. In the present work isolation of a DNA sequence encoding the mature peptide of a trypsin inhibitor McTI-Ⅱ, its cloning and expression as a recombinant protein using Pichia pastoris have been reported. Recombinant McTI-Ⅱ inhibited bovine trypsin at 1 ： 1 molar ratio, as expected, but did not inhibit chymotrypsin or elastase. McTI-Ⅱ also strongly inhibited trypsin-like proteinases （81% inhibition） as well as the total proteolytic activity of digestive proteinases （70% inhibition） from the midgut of H. armigera larvae. The insect larvae fed with McTI-Ⅱ-incorporated artificial diet suffered over 70% reduction in the average larval weight after 12 days of feeding. Moreover, ingestion of McTI-Ⅱ resulted in 23% mortality in the larval population. The strong antimetabolic activity of McTI-Ⅱ toward H. armigera indicates its probable use in developing insect tolerance in susceptible plants.
