无色杆菌毒蛋白对菜粉蝶中肠的组织病理学影响

Histopathological Effects of the Protein Toxin from Photorhabdus luminescens on the Midgut of Pieris rapae

无色杆菌毒蛋白经口进入菜粉蝶幼虫体内 6、12、18、2 4h以后 ,菜粉蝶幼虫的中肠组织逐渐遭到破坏 ,开始有些肠壁细胞伸长 ,在顶端形成囊泡 ,以后囊泡和细胞核脱落进入肠腔 .处理后期临近死亡的幼虫中肠肠壁组织被严重破坏 ,仅残留基层细胞 ,并形成一些空腔 ,从而影响昆虫的正常取食 .

Photorhabdus luminescens is a bacterium which is mutualistic with entomophagous nematodes, and seretes the protein toxin following its release into the insect hemocoel.The protein toxin had high killing activities against a wide range of insects.After the insect took in the toxin,the changing of enzyme's internal function of the insects and the destruction of the organs resulted in the death of the insects. It was reported that the toxin ingested by the larvae of Pieris rapae orally brought about a series of pathological. The larvae ingesting the toxin at 6,12,18 and 24 h respectively, the cells of their midguts were destroyed progressively,some cells of midgut exterding,large cytoplasimic vesicles extruding on the end of the cells,and the vesicles and cell nuclei falling off epithelium into the gut lumen.The epithelia of the dying larvae were seriously destroyed,and only the basic cells remained. While some empty lumens formed, the normal growth of the larvae was affected by this pathological change.The results of the experiment showed Photorhabdus luminescens protein toxin(plpt) that could lead to serious pathogenesis in the midgut of the larvae.