ABSTRACT

The Hessian fly causes severe economic losses in host wheat. The genome complexity of hexaploid wheat makes functional characterization of candidate defense genes extremely challenging. Kitaake rice, a model and simpler genome, exhibits responses resembling nonhost resistance to Hessian fly. Larvae feeding on Kitaake rice plants do not develop beyond first-instars similar to resistant host wheat, although, they show prolonged survival. Kitaake nonhost differs from nonhost Brachypodium, where some larvae develop into second-instars. Kitaake rice plants exhibit a molecular response similar to not only resistant but also susceptible host wheat for six Hessian fly-responsive biomarker genes assayed. Further, in Kitaake, lectins and secondary metabolites may play an important role in early defense preventing the larvae from developing. The phenotypic and molecular characterization of Kitaake rice reveals its suitability as a surrogate model genome for undertaking downstream functional genomics studies of candidate wheat genes that respond to Hessian fly larval attack.

摘要

黑森州的苍蝇对寄主小麦造成严重的经济损失。六倍体小麦的基因组复杂性使得候选防御基因的功能表征极具挑战性。Kitaake水稻是一个模型和更简单的基因组，表现出类似于非寄主对黑森州苍蝇的抗性。尽管以北大稻植物为食的幼虫长出存活期，但与抗性寄主小麦相似，其幼龄期不会超过初生幼虫。北岳非寄主与非寄主Brachypodium不同，其中一些幼虫发育成第二龄幼虫。Kitaake水稻植物表现出的分子反应不仅对抗性小麦而且对易感寄主小麦均具有相似的分子响应，可检测到六个黑森州果蝇响应生物标记基因。此外，在Kitaake中，凝集素和次生代谢产物可能在防止幼虫发育的早期防御中起重要作用。Kitaake水稻的表型和分子特征表明，它适合作为替代模型基因组，用于进行对黑森州苍蝇幼虫攻击作出反应的候选小麦基因的下游功能基因组学研究。