Department of Entomology, NDSU, Fargo, 58105, USA.
Phytopathology. 2010 Mar;100(3):279-89. doi: 10.1094/PHYTO-100-3-0279.
Features shared by host-specific phytophagous insects and biotrophic plant pathogens include gene-for-gene interactions and the ability to induce susceptibility in plants. The Hessian fly shows both. To protect against Hessian fly, grasses have H genes. Avirulent larvae die on H-gene-containing resistant plants but the cause of death is not known. Imaging techniques were used to examine epidermal cells at larval attack sites, comparing four resistant wheat genotypes (H6, H9, H13, and H26) to a susceptible genotype. Present in both resistant and susceptible plants attacked by larvae were small holes in the tangential cell wall, with the size of the holes (0.1 microm in diameter) matching that of the larval mandible. Absent from attacked resistant plants were signs of induced susceptibility, including nutritive tissue and ruptured cell walls. Present in attacked resistant plants were signs of induced resistance, including cell death and fortification of the cell wall. Both presumably limit larval access to food, because the larva feeds on the leaf surface by sucking up liquids released from ruptured cells. Resistance was associated with several subcellular responses, including elaboration of the endoplasmic reticulum-Golgi complex and associated vesicles. Similar responses are observed in plant resistance to fungi, suggesting that "vesicle-associated penetration resistance" also functions against insects.
专性寄生于植物的植食性昆虫和生物型植物病原体具有一些共同特征，包括基因对基因互作和诱导植物易感性的能力。麦长管蚜就同时具有这两种特征。为了抵御麦长管蚜，禾本科植物具有 H 基因。无毒性幼虫会在含有 H 基因的抗性植物上死亡，但具体原因尚不清楚。本研究采用成像技术，比较了四个抗性小麦基因型（H6、H9、H13 和 H26）与一个感病基因型，对受幼虫攻击的表皮细胞进行了研究。在受幼虫攻击的抗性和感病植物中都存在切线细胞壁上的小孔，孔的大小（直径 0.1 微米）与幼虫下颚的大小相匹配。在受攻击的抗性植物中没有诱导易感性的迹象，包括营养组织和破裂的细胞壁。在受攻击的抗性植物中存在诱导抗性的迹象，包括细胞死亡和细胞壁的加固。这两种情况都可能限制幼虫获取食物，因为幼虫通过吸食破裂细胞释放的液体从叶片表面取食。抗性与几种亚细胞反应有关，包括内质网-高尔基体复合体及其相关小泡的形成。在植物对真菌的抗性中也观察到了类似的反应，这表明“小泡相关的穿透抗性”也能抵抗昆虫。
