The Ry sto immune receptor recognizes a broadly conserved feature of potyviral coat proteins
The Ry sto immune receptor recognizes a broadly conserved feature of potyviral coat proteins
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Ry sto 免疫受体识别马铃薯病毒外壳蛋白的广泛保守特征
DOI：
10.1101/2021.05.20.444601
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Grech-Baran M
中科院分区：
文献类型：
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作者：
Grech-Baran M
马铃薯Y病毒属是植物RNA病毒中最大的一类，在许多作物中造成重大损失。其中，马铃薯Y病毒（PVY）是特别重要的，并增强了其他病毒感染的严重性。Ry sto基因赋予PVY抗性并编码识别PVY外壳蛋白（CP）的TIR-NLR细胞内免疫受体。为了确定由Ry sto感知的最小CP片段，我们创建了一系列截短的CP变体，并在Ry sto转基因植物中表达这些CP衍生物。影响149个氨基酸CP核心区的缺失失去了触发Ry sto依赖性防御激活的能力。此外，马铃薯Y病毒CP的高度保守的RNA结合口袋的氨基酸残基Ser 126、Arg 157和Asp 201中的点突变减少或消除了Ry sto依赖性应答，表明CP核心的适当折叠是Ry sto介导的识别所需的。与这些数据相一致，我们发现Ry sto识别共享相似核心区域的各种病毒的CP，但不识别那些缺乏它的CP。最后，我们证明了Ry sto提供对李痘病毒和芜菁花叶病毒的免疫，展示了其在抗病作物工程中的广泛应用。同时，我们表明CP触发的Ry sto激活是SAG 101-而不是PAD 4-或SA-水平依赖性的。我们的发现为R蛋白如何通过检测高度保守的结构模式来检测病毒提供了新的线索。
Potyviruses are the largest group of plant RNA viruses, causing significant losses in many crops. Among them, potato virus Y (PVY) is particularly important, and enhances the severity of infections by other viruses. The Ry sto gene confers PVY resistance and encodes a TIR-NLR intracellular immune receptors that recognizes PVY coat protein (CP). To define a minimal CP fragment sensed by Ry sto, we created a series of truncated CP variants and expressed these CP derivatives in Ry sto transgenic plants. Deletions that affect the 149 amino acid CP core region lose the ability to trigger Ry sto-dependent defence activation. Furthermore, point mutations in the amino acid residues Ser126, Arg157, and Asp201 of the highly conserved RNA-binding pocket of potyviral CP, reduce or abolish Ry sto-dependent responses, demonstrating that appropriate folding of the CP core is required for Ry sto-mediated recognition. Consistent with these data, we found Ry sto recognises CPs of various viruses that share a similar core region, but not those lacking it. Finally, we demonstrated that Ry sto provides immunity to plum pox virus and turnip mosaic virus, demonstrating its wide range of applications in disease-resistant crop engineering. In parallel, we showed that CP triggered Ry sto activation is SAG101-but not PAD4-or SA-level dependent. Our findings shed new light on how R proteins can detect viruses by sensing highly conserved structural patterns.