The Arabidopsis RPS4 bacterial-resistance gene is a member of the TIR-NBS-LRR family of disease-resistance genes
The Arabidopsis RPS4 bacterial-resistance gene is a member of the TIR-NBS-LRR family of disease-resistance genes
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DOI：
10.1046/j.1365-313x.1999.t01-1-00600.x
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发表时间：
1999-11-01
期刊：
影响因子：
7.2
通讯作者：
Staskawicz, BJ
中科院分区：
文献类型：
--
作者：
Gassmann, W;Hinsch, ME;Staskawicz, BJ
植物抗病（R）基因介导的特异性识别入侵病原体携带同源无毒（avr）决定因素。RPS 4是拟南芥第5号染色体上的一个抗病基因座，它对拟南芥假单胞菌致病变种（Pseudomonaserichingae pv.）表达avrRps 4的番茄。我们已经分离的RPS 4基因，使用基于图位的克隆方法。RPS 4编码1217个氨基酸的预测蛋白，其含有与果蝇Toll蛋白和哺乳动物白细胞介素-1受体的胞内结构域（TIR结构域）同源的N-末端、三核苷酸结合位点（NBS）和富含亮氨酸的重复序列（LRR）。观察到RPS 4 mRNA的不完全剪接，这可能导致主要由TIR和NBS结构域组成的截短蛋白产物。这些特征将RPS 4分类为由N、L 6和RPP 5建立的TIR-NBS-LRR R基因家族的成员，其分别决定对病毒、真菌和卵菌病原体的抗性。先前的工作表明，RPS 4，像其他拟南芥TIR-NBS-LRR R基因指定的抗卵菌，是依赖于一个功能性的EDS 1等位基因的抗病信号。因此，本文提出的RPS 4的表征确立了TIR-NBS-LRR R基因在对细菌病原体的抗性中的作用，并为R基因对EDS 1的依赖性由R蛋白结构而不是病原体类型决定的模型提供了证据。RPS 4的克隆和avrRps 4的分离为拟南芥TIR-NBS-LRR R基因信号通路的遗传和分子解剖提供了分子工具。
Plant-disease resistance (R) genes mediate the specific recognition of invading pathogens carrying cognate avirulence (avr) determinants. RPS4 is a disease-resistance locus on chromosome 5 of Arabidopsis thaliana specifying resistance to strains of Pseudomonas syringae pv. tomato expressing avrRps4. We have isolated the RPS4 gene using a map-based cloning approach. RPS4 encodes a predicted protein of 1217 amino acids that contains an N-terminus with homology to the intracellular domains of the Drosophila Toll protein and the mammalian interleukin-1 receptor (TIR domain), a tripartite nucleotide-binding site (NBS), and leucine-rich repeats (LRR). Incomplete splicing of the RPS4 mRNA was observed, which may give rise to truncated protein products consisting mainly of the TIR and NBS domains. These features classify RPS4 as a member of the TIR-NBS-LRR R gene family founded by N, L6 and RPP5, which determine resistance to viral, fungal and oomycete pathogens, respectively. Previous work has shown that RPS4, like other Arabidopsis TIR-NBS-LRR R genes specifying resistance to oomycetes, is dependent on a functional EDS1 allele for disease-resistance signaling. The characterization of RPS4 presented here thus establishes a role for TIR-NBS-LRR R genes in resistance to bacterial pathogens, and provides evidence for the model that dependence of R genes on EDS1 is determined by R protein structure, and not by pathogen type. The cloning of RPS4 and the previous isolation of avrRps4 provide the molecular tools for a genetic and molecular dissection of the TIR-NBS-LRR R gene signaling pathway in Arabidopsis.