大豆胰蛋白酶抑制剂与棉酚或丹宁混用对棉铃虫中肠蛋白酶和生长率的影响

本文报告了大豆胰蛋白酶抑制剂（ＳＴＩ）与棉酚、丹宁酸单一和协同作用对棉铃虫Ｈｅｌｉｃｏｖｅｒｐａａｒｍｉｇｅｒａ（Ｈｕｂｎｅｒ）幼虫中肠蛋白酶活性和生长速率的影响。在离体条件下，ＳＴＩ、棉酚和丹宁酸均对中肠蛋白酶有抑制作用，以ＳＴＩ的作用最强。活体试验表明，人工饲料中０．８４％（干重）的ＳＴＩ对强碱性类胰蛋白酶活力有显著抑制作用；０．３％丹宁酸则对弱碱性类胰蛋白酶和总蛋白酶活力有显著抑制作用；０．３％棉酚对几种蛋白酶活力的影响均不显著。三者均能显著抑制幼虫的生长，而ＳＴＩ与棉酚或丹宁酸的协同作用比三者的单独作用更能有效地抑制幼虫的生长发育和中肠蛋白酶活性。

EFFECT OF SOYBEAN TRYPSIN INHIBITOR,GOSSYPOL AND TANNIC ACID ON THE MIDGUT PROTEASE ACTIVITIES AND. GROWTH OF HELICOVERPA ARMIGERA LARVAE

The effects of soybean trypsin inhibitor (STI), gossypol, and tannic acid on the growth and digestive physiology of cotton bollworm, Helicoverpa armigera (Hubner) were studied. Each of three agents inhibited larval midgut proteolytic activity in vitro; STI was the most effective. When incorporated into an artificial diet,0.84% (dry weight) STI significantly reduced the high alkaline trypsin-like enzyme activity by 18%; 0.3% tannic acid significantly decreased the low alkaline trypsin-like enzyme activity and total proteolytic activity by 22% and 18% respectively; and 0.3% gossypol had no significant effect on proteolysis. All the three agents remarkably suppressed the growth of larvae. Co-occurrences of STI and gossypol or tannic acid respectively declined the low alkaline trypsin-like enzyme activity by 34% and 66%, the high alkaline trypisn-like enzyme activity by 33% and 55%, and the total proteolytic activity by 30% and 66%. Co-occurrence of STI and tannic acid also reduced chymotrypsin-like enzyme activity by 53%. Both gossypol and tannic acid potentiated the larval growth inhibitory activity of STI, and this implicates the protease inhibitor engineered into the cotton with high gossypol and /or tannin content may achieve greater protection against the cotton bollworm.