伯氏嗜线虫致病杆菌蛋白酶抑制剂Xbpi-1对豌豆蚜Acyrthosiphon pisum Harris生物活性的研究

摘要

蛋白酶抑制剂是一类能够抑制蛋白水解酶活性的小分子蛋白质，在昆虫肠道内通过抑制蛋白酶的活性，可以干扰昆虫的正常生长和发育。本文利用体外重组表达的蛋白酶抑制剂Xbpi-1，研究了Xbpi-1对豌豆蚜Acyrthosiphon pisum Harris的杀虫活性及其生化机制。结果表明，取食含蛋白酶抑制剂Xbpi-1浓度为50、200、400、800μg·mL^-1人工饲料的豌豆蚜，96h后的校正死亡率分别为2．1％、9-4％、19．7％和50．9％，虫重分别减少12_3％、20．3％、25．7％和33．7％。生化测定结果表明，4种浓度处理的豌豆蚜体内总蛋白酶、氨肽酶、胰蛋白酶、胰凝乳蛋白酶的活性均有显著降低，浓度为800μ·mL^-1时，其酶活性分别降低了29．6％、26．1％、23．5％和23．8％。本研究结果说明，蛋白酶抑制剂Xbpi-1对豌豆蚜具有较好的生物活性，为进一步开发应用于豌豆蚜等刺吸式害虫的防治提供了理论依据。%Protease inhibitors are capable of affecting insect survival and development by inhibition of the activities of proteases. In this study, the biological activity of recombinant protease inhibitor Xbpi-1 against the pea aphid, Acyrthosiphon pisum Harris, and the effects on the activities of aphid proteases were evaluated. The pea aphids fed on artificial diet containing 50, 200, 400, 800 μg·mL^-1 Xbpi-1 protein showed calibrated mortality of 2.1%, 9.4%, 19.7%, 50.9%, and aphid weights were reduced 12.3%, 20.3%, 25.7%, 33.7%, respectively compared with those of the control. The results showed that the activities of pea aphid proteases (trypsin, chymotrypsin, leucine aminopeptidase and total protinase) were significantly inhibited by the protease inhibitor protein. The results indicated that the protease inhibitor protein used in this study may be a potential bio-pesticide for controlling of sucking insect pests.