USDA-ARS Crop Production and Pest Control Research Unit, West Lafayette, IN 47907, USA.
J Insect Physiol. 2010 Jul;56(7):754-60. doi: 10.1016/j.jinsphys.2010.01.005. Epub 2010 Feb 4.
The focus of the present study was to compare ultrastructure in the midguts of larvae of the Hessian fly, Mayetiola destructor (Say), under different feeding regimens. Larvae were either fed on Hessian fly-resistant or -susceptible wheat, and each group was compared to starved larvae. Within 3h of larval Hessian fly feeding on resistant wheat, midgut microvilli were disrupted, and after 6h, microvilli were absent. The disruption in microvilli in larvae feeding on resistant wheat were similar to those reported for midgut microvilli of European corn borer, Ostrinia nubilasis (Hubner), larvae fed a diet containing wheat germ agglutinin. Results from the present ultrastructural study, coupled with previous studies documenting expression of genes encoding lectin and lectin-like proteins is rapidly up-regulated in resistant wheat to larval Hessian fly, are indications that the midgut is a target of plant resistance compounds. In addition, the midgut of the larval Hessian fly is apparently unique among other dipterans in that no peritrophic membrane was observed. Ultrastructural changes in the midgut are discussed from the prospective of their potential affects on the gut physiology of Hessian fly larvae and the mechanism of antibiosis in the resistance of wheat to Hessian fly attack.
本研究的重点是比较不同喂养方式下玉米穗虫幼虫中肠的超微结构。幼虫要么以玉米穗虫抗性或敏感的小麦为食，每个组都与饥饿的幼虫进行比较。在幼虫取食抗性小麦的 3 小时内，中肠微绒毛被破坏，6 小时后微绒毛消失。取食抗性小麦的幼虫的微绒毛破坏与先前报道的欧洲玉米螟幼虫中肠微绒毛的破坏相似，这些幼虫喂食含有麦胚凝集素的饮食。本超微结构研究的结果，加上先前记录编码凝集素和凝集素样蛋白的基因在抗性小麦中快速上调的研究结果表明，中肠是植物抗性化合物的靶标。此外，幼虫玉米穗虫的中肠在其他双翅目昆虫中显然是独特的，因为没有观察到围食膜。从中肠生理学和小麦对玉米穗虫攻击的抗生性的角度讨论了中肠的超微结构变化。
