Franco Octávio L, Dias Simoni C, Magalhães Claudio P, Monteiro Ana C S, Bloch Carlos, Melo Francislete R, Oliveira-Neto Osmundo B, Monnerat Rose G, Grossi-de-Sá Maria Fátima
Embrapa Recursos Genéticos e Biotecnologia, S.A.I.N. Parque Rural, Final W5, Asa Norte, 70770-900, Brasilia-DF, Brazil.
Phytochemistry. 2004 Jan;65(1):81-9. doi: 10.1016/j.phytochem.2003.09.010.
The cotton boll weevil, Anthonomus grandis, is an economically important pest of cotton in tropical and subtropical areas of several countries in the Americas, causing severe losses due to their damage in cotton floral buds. Enzymatic assays using gut extracts from larval and adult boll weevil have demonstrated the presence of digestive serine proteinase-like activities. Furthermore, in vitro assays showed that soybean Kunitz trypsin inhibitor (SKTI) was able to inhibit these enzymes. Previously, in vivo effects of black-eyed pea trypsin chymotrypsin inhibitor (BTCI) have been demonstrated towards the boll weevil pest. Here, when neonate larvae were reared on an artificial diet containing SKTI at three different concentrations, a reduction of larval weight of up to 64% was observed for highest SKTI concentration 500 microM. The presence of SKTI caused an increase in mortality and severe deformities of larvae, pupae and adult insects. This work therefore represents the first observation of a Kunitz trypsin inhibitor active in vivo and in vitro against A. grandis. Bioassays suggested that SKTI could be used as a tool in engineering crop plants, which might exhibit increased resistance against cotton boll weevil.
棉铃象甲（Anthonomus grandis）是美洲几个国家热带和亚热带地区棉花的一种具有重要经济意义的害虫，因其对棉花花蕾的损害而造成严重损失。使用幼虫和成虫棉铃象甲肠道提取物进行的酶活性测定表明存在消化性丝氨酸蛋白酶样活性。此外，体外试验表明大豆Kunitz胰蛋白酶抑制剂（SKTI）能够抑制这些酶。此前，已证明黑眼豆胰蛋白酶糜蛋白酶抑制剂（BTCI）对棉铃象甲害虫具有体内效应。在此，当新生幼虫在含有三种不同浓度SKTI的人工饲料上饲养时，在最高SKTI浓度500微摩尔时观察到幼虫体重减轻高达64%。SKTI的存在导致幼虫、蛹和成虫的死亡率增加以及严重畸形。因此，这项工作首次观察到一种Kunitz胰蛋白酶抑制剂在体内和体外对棉铃象甲均有活性。生物测定表明，SKTI可作为工程作物植物的一种工具，这些作物可能表现出对棉铃象甲的抗性增强。
