烟夜蛾血淋巴凝集素活性的研究

Hemagglutination activity of lectins in the hemolymph of Helicoverpa assulta

利用血凝法检测烟夜蛾Helicoverpa assulta血淋巴对红细胞的凝集活性和不同发育期凝集素水平,同时选取13种糖进行凝集素糖抑制反应,以明确该凝集素与烟夜蛾发育的关系和糖结合特性.研究结果表明,在烟夜蛾的不同发育期均检测有凝集素,但各龄幼虫及不同日龄蛹的凝集活性存在明显差异,雌蛹凝集素水平高于同日龄的雄蛹,表明凝集素与发育期、虫龄及蜕皮过程有关,且与性别相关.烟夜蛾蛹血淋巴凝集素活性与近缘种棉铃虫H.armigera的相类似,均被D-半乳糖、L-鼠李糖、麦芽糖、乳糖明显抑制;D-葡萄糖、D-果糖、L-岩藻糖和蔗糖等也有抑制作用,但抑制程度不同;L-阿拉伯糖与棉铃虫凝集素的专一性结合更强;N-乙酰葡萄糖胺和L-山梨糖只对棉铃虫凝集素有抑制作用,而对烟夜蛾凝集素无抑制作用,说明这2个近缘种的凝集素不完全相同.

To understand the relationship between lectins and development in H. assulta, and the sug- ar-binding specificity of H. assulta lectin, Hemagglutination assays were used to determine the hemag- glutinating activity （HA） of haemolymph extracted from Helicoverpa assulta to the erythrocytes, and the changes of HA titer during different developmental stages of H. assulta. Meanuhile, thirteen sugars were tested to determine their inhibitory effect on H. assulta lectin. The results showed that lectins were detected during all developmental stages of H. assulta. Hemagglutination activity （HA） titer fluctuated between and within the various developmental stages, particularly in different larval instars and pupal ages, female pupal H. assulta had higher HA titer than their male cohorts. These results in- dicated that HA of lectins may be related to developmental stage, larval instar and molting process, and was dependent on sex. The carbohydrate binding specificity of the lectins in pupal hemolymph from H. assulta and H. armigera was determined by comparing the inhibitory activity of different sug- ars. The carbohydrates, which inhibited HA of H. assulta and H. armigera, were similar. It showed that HA was obviously inhibited by D-galactose, L-rhamnose, and maltose and lactose, and partly in- hibited by D-glucose, D-fructose, L-fucose and sucrose et al. However, only H. armigera lectins had stronger binding specificity with L-arabinose, N-acetyl-glucosamine and L-sorbose could inhibit HA ofH. armigera, but did not inhibit HA of H. assulta. It was suggested that lectins detected from H. as- sulta are different from that in H. armigera.