慈菇蛋白酶抑制剂对亚洲玉米螟消化酶的影响

THE EFFECT OF INGESIED ARROWHEAD PROTEINASE INHIBITOR ON DIGESTIVE ENZYME OF ASIAN CORN BORER,OSTRINIA FURNACALIS

亚洲玉米螟幼虫中肠消化酶主要为胰蛋白酶。利用慈菇蛋白酶抑制剂研究它对玉米螟消化酶的影响，发现这种抑制剂体外强烈抑制玉米螟幼虫中肠消化酶。同时我们又比较了长时间取食（三龄至五龄第二天）和短时间取食（四龄未取食４８小时）抑制剂的幼虫体内胰蛋白酶活性，当它们短时间取食抑制剂后，体内消化酶水平迅速下降，取食更长时间时，胰蛋白酶活力下降更明显，仅为对照的２７．２％。由此可见，慈菇蛋白酶抑制剂严重影响了玉米螟的正常消化，阻断了玉米螟营养与食物间的联系，使玉米螟生长发育不良。

Evlbence was presented that Asian corn borer,O strinia furnacalis,depended ontrypsin for protein digestion. We studied the effect of AHI on the larval digestive physiology us- ing a artificial diet with AHI at 0.4%(d.wt )level. The in vitro inhibition of AHI on the activi- ty of trypsin isolated from larval borers was g reat.We also examined both acute and chronic ef- fects of ingestion of AHI on the level of digestive enzyme activity in the larval borer. We foundthat acute ingestion of AHI by the larvae resulted in a siginmcant decrease in tryptic activitywhen compared with insects feeding on control diets. When the larvae chronically were ingestedwith AHI,their tryptic activity was extremely reduced to 27.2%of control.These results sug-gest that AHI seriously affects the normal digestion of Asian corn borer and hinders relationshipbetween the larval nutrition and food resulting in harmful effects on the larval growth and devel- opment.