SNARE-protein-mediated disease resistance at the plant cell wall
SNARE-protein-mediated disease resistance at the plant cell wall
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DOI：
10.1038/nature02076
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发表时间：
2003-10-30
期刊：
影响因子：
64.8
通讯作者：
Schulze-Lefert, P
中科院分区：
文献类型：
--
作者：
Collins, NC;Thordal-Christensen, H;Schulze-Lefert, P
病原真菌无法突破植物细胞壁是非病原菌宿主范围之外的非宿主植物物种免疫的一个主要组成部分，并且在“易感”宿主植物上占一定比例的感染尝试失败（基础抗性）（1 - 4）。这两种形式的穿透抗性在分子水平上都尚未被了解。我们开发了一种筛选拟南芥穿透（pen）突变体的方法，这些突变体在针对大麦白粉菌（Blumeria graminis f. sp. hordei）的非宿主穿透抗性方面存在缺陷，并且我们分离出了PEN1基因。我们还分离出了大麦的ROR2（参考文献2），它是针对大麦白粉菌的基础穿透抗性所必需的。这些基因编码功能同源的突触融合蛋白，证明了单子叶植物和双子叶植物中非宿主抗性和基础穿透抗性之间存在一种机制上的联系。我们表明，大麦中的抗性需要一种能够与ROR2形成二元SNAP受体（SNARE）复合物的SNAP - 25（突触体相关蛋白，分子量25 kDa）同源物。穿透位点处囊泡行为的遗传控制以及PEN1/ROR2在质膜上的定位，与所提出的SNARE复合物介导的胞吐作用和/或同型囊泡融合事件在抗性中的参与是一致的。与SNARE依赖性穿透抗性相关的功能对于由小种特异性抗性（R）基因介导的免疫是可有可无的，这突出了这两种抗性形式之间的根本差异。
Failure of pathogenic fungi to breach the plant cell wall constitutes a major component of immunity of non-host plant species species outside the pathogen host range - and accounts for a proportion of aborted infection attempts on 'susceptible' host plants (basal resistance)(1-4). Neither form of penetration resistance is understood at the molecular level. We developed a screen for penetration ( pen) mutants of Arabidopsis, which are disabled in non-host penetration resistance against barley powdery mildew, Blumeria graminis f. sp. hordei, and we isolated the PEN1 gene. We also isolated barley ROR2 (ref. 2), which is required for basal penetration resistance against B. g. hordei. The genes encode functionally homologous syntaxins, demonstrating a mechanistic link between non-host resistance and basal penetration resistance in monocotyledons and dicotyledons. We show that resistance in barley requires a SNAP-25 (synaptosome-associated protein, molecular mass 25 kDa) homologue capable of forming a binary SNAP receptor ( SNARE) complex with ROR2. Genetic control of vesicle behaviour at penetration sites, and plasma membrane location of PEN1/ROR2, is consistent with a proposed involvement of SNARE-complex-mediated exocytosis and/or homotypic vesicle fusion events in resistance. Functions associated with SNARE-dependent penetration resistance are dispensable for immunity mediated by race-specific resistance (R) genes, highlighting fundamental differences between these two resistance forms.