Departamento de Tecnologia de Alimentos e Saúde Pública, Centro de Ciências Biológicas e da Saúde, Universidade Federal de Mato Grosso do Sul (UFMS), Campo Grande, MS, Brazil.
J Insect Sci. 2012;12:62. doi: 10.1673/031.012.6201.
The objective of this work was to study the insecticidal effect of labramin, a protein that shows lectin-like properties. Labramin was isolated from seeds of the Beach Apricot tree, Labramia bojeri A. DC ex Dubard (Ericales: Sapotaceae), and assessed against the development of the Mediterranean flour moth Ephestia kuehniella Zeller (Lepidoptera: Pyralidae), an important pest of stored products such as corn, wheat, rice, and flour. Results showed that labramin caused 90% larval mortality when incorporated in an artificial diet at a level of 1% (w/w). The presence of 0.25% labramin in the diet affected the larval and pupal developmental periods and the percentage of emerging adults. Treatments resulted in elevated levels of trypsin activity in midgut and fecal materials, indicating that labramin may have affected enzyme-regulatory mechanisms by perturbing peritrophic membranes in the midgut of is. kuehniella larvae. The results of dietary experiments with E. kuehniella larvae showed a reduced efficiency for the conversion of ingested and digested food, and an increase in approximate digestibility and metabolic cost. These findings suggest that labramin may hold promise as a control agent to engineer crop plants for insect resistance.
本研究旨在研究 labramin 的杀虫效果，labramin 是一种具有凝集素样特性的蛋白质。labramin 从 Beach Apricot 树（Labramia bojeri A. DC ex Dubard）的种子中分离出来，并对地中海粉斑螟（Ephestia kuehniella Zeller）（鳞翅目：Pyralidae）的发育进行了评估，地中海粉斑螟是玉米、小麦、水稻和面粉等储存产品的重要害虫。结果表明，当以 1%（w/w）的水平掺入人工饲料中时，labramin 可导致 90%的幼虫死亡。饲料中存在 0.25%的 labramin 会影响幼虫和蛹的发育周期以及成虫的出现率。处理导致中肠和粪便中胰蛋白酶活性升高，表明 labramin 可能通过扰乱地中海粉斑螟幼虫中肠的围食膜影响酶调节机制。用 E. kuehniella 幼虫进行的饮食实验结果表明，摄入和消化的食物的转化率降低，近似消化率和代谢成本增加。这些发现表明，labramin 可能作为一种控制剂，有望用于培育抗虫作物。
