Eves-van den Akker Sebastian, Lilley Catherine J, Jones John T, Urwin Peter E
Centre for Plant Sciences, University of Leeds, Leeds, United Kingdom; Cell and Molecular Sciences Group, Dundee Effector Consortium, James Hutton Institute, Invergowrie, Dundee, United Kingdom.
Centre for Plant Sciences, University of Leeds, Leeds, United Kingdom.
PLoS Pathog. 2014 Sep 25;10(9):e1004391. doi: 10.1371/journal.ppat.1004391. eCollection 2014 Sep.
Sedentary endoparasitic nematodes are obligate biotrophs that modify host root tissues, using a suite of effector proteins to create and maintain a feeding site that is their sole source of nutrition. Using assumptions about the characteristics of genes involved in plant-nematode biotrophic interactions to inform the identification strategy, we provide a description and characterisation of a novel group of hyper-variable extracellular effectors termed HYP, from the potato cyst nematode Globodera pallida. HYP effectors comprise a large gene family, with a modular structure, and have unparalleled diversity between individuals of the same population: no two nematodes tested had the same genetic complement of HYP effectors. Individuals vary in the number, size, and type of effector subfamilies. HYP effectors are expressed throughout the biotrophic stages in large secretory cells associated with the amphids of parasitic stage nematodes as confirmed by in situ hybridisation. The encoded proteins are secreted into the host roots where they are detectable by immunochemistry in the apoplasm, between the anterior end of the nematode and the feeding site. We have identified HYP effectors in three genera of plant parasitic nematodes capable of infecting a broad range of mono- and dicotyledon crop species. In planta RNAi targeted to all members of the effector family causes a reduction in successful parasitism.
定居型内寄生线虫是专性活体营养型生物，它们利用一系列效应蛋白来改变宿主根组织，从而创建并维持一个作为其唯一营养来源的取食位点。基于植物与线虫活体营养相互作用中相关基因的特征假设来指导鉴定策略，我们对来自马铃薯金线虫（Globodera pallida）的一组新的高变细胞外效应蛋白（称为HYP）进行了描述和表征。HYP效应蛋白构成一个大的基因家族，具有模块化结构，并且在同一种群的个体之间具有无与伦比的多样性：所测试的线虫个体中没有两个具有相同的HYP效应蛋白基因组合。个体在效应蛋白亚家族的数量、大小和类型上存在差异。原位杂交证实，HYP效应蛋白在与寄生阶段线虫的化感器相关的大型分泌细胞的整个活体营养阶段均有表达。编码的蛋白质被分泌到宿主根中，通过免疫化学方法可在质外体中、线虫前端和取食位点之间检测到它们。我们在能够感染多种单子叶和双子叶作物物种的三个植物寄生线虫属中鉴定出了HYP效应蛋白。针对效应蛋白家族所有成员的植物体内RNA干扰会导致成功寄生率降低。
