王雄雅 李星 白素芬 李欣

摘要 ：昆虫唾液在成功取食寄主中发挥关键作用。而有关植食性昆虫唾液（反吐液）的研究多集中在与寄主植物的互作关系上，鲜有涉及唾液免疫因子的研究。凝集素作为模式识别受体，在病原物的识别中发挥重要作用，是昆虫重要的免疫因子。棉铃虫幼虫血淋巴中已报道的凝集素种类至少有8种，但其唾液中是否存在凝集素却未见报道。本文通过与鸡血红细胞的血凝反应检测到棉铃虫幼虫唾液中含有凝集活性物质，凝集效价高达29。显微观察显示，唾液对鸡血红细胞具有明显的凝集作用。经35%和45%硫酸铵盐析沉淀获得的组分具有明显凝集活性，表明唾液中的凝集活性物质为蛋白质。通过糖抑制试验，发现棉铃虫唾液凝集素与其血淋巴凝集素的糖结合谱存在差异，表明他们是不同的凝集素种类。棉铃虫唾液凝集素的揭示为理解植食性昆虫唾液的免疫功能提供了新的证据。

关键词 ：凝集素; 棉铃虫; 唾液（反吐液）; 凝集活性; 糖抑制试验

中图分类号：

Q 965文献标识码： A

DOI： 10.16688/j.zwbh.2019529

A preliminary study of lectin in the saliva （regurgitant） of Helicoverpa armigera

WANG Xiongya1，2， LI Xing1， BAI Sufen1， LI Xin1*

（1. College of Plant Protection， Henan Agricultural University， Zhengzhou 450002， China;

2. Institute of Plant Protection， Chinese Academy of Agricultural Sciences， Beijing 100193， China）

Abstract ：Insect saliva plays a major role in successful feeding on host. In recent years， the researches on salivary components of herbivory insects have mainly focused on the coevolution and relationships between insects and plants， and less attention have been paid to the factors involved in immunity. Lectins， as pattern recognition receptors， play important roles in recognizing foreign substances in the insect immune system. There are at least eight Ctype lectins in larval hemolymph of Helicoverpa armigera， but until now no lectin has ever been reported in its saliva （regurgitant）. In the present study， the agglutination activity of H.armigera saliva was detected by hemagglutination reaction with chicken erythrocytes. The agglutination reaction of chicken erythrocytes treated with H.armigera saliva was observed obviously under phase contrast microscope. By ammonium sulfate precipitation， the protein precipitated by 35% and 45% ammonium sulfate showed obvious agglutination activity， indicating that the substance with agglutination activity in saliva was a protein. The carbohydrateinhibition assay discovered the difference between saliva and hemolymph in carbohydratebinding profiles of lectin， suggesting that they were different lectins. The lectin identified in saliva of H.armigera adds new proof to the understanding of immunity of phytophagous insects.

Key words ：lectin; Helicoverpa armigera; saliva （regurgitant）; agglutination activity; carbohydrate inhibition agglutination test

植食性昆蟲在取食寄主植物时会分泌大量唾液，成分复杂，含有许多重要的生理功能因子，具有湿润口器、消化、解毒、免疫、化学感受，以及调控寄主植物防御反应等功能[1]。在植食性昆虫与寄主植物长期协同进化的过程中，唾液发挥着至关重要的作用。唾液成分中激发子、植食性昆虫相关模式分子和效应子等是二者之间起联系作用的纽带[2]。……