A replicase of Potato virus X acts as the resistance-breaking determinant for JAX1-mediated resistance.
A replicase of Potato virus X acts as the resistance-breaking determinant for JAX1-mediated resistance.
复制标题
DOI：
10.1094/mpmi-04-13-0094-r
复制
发表时间：
2013-08
期刊：
影响因子：
--
通讯作者：
Kyoko Sugawara;Takuya Shiraishi;Tetsuya Yoshida;N. Fujita;O. Netsu;Y. Yamaji;S. Namba
中科院分区：
文献类型：
--
作者：
Kyoko Sugawara;Takuya Shiraishi;Tetsuya Yoshida;N. Fujita;O. Netsu;Y. Yamaji;S. Namba
凝集素介导的抗性（LMR）被认为是植物抗病毒天然免疫的一个未被表征的分支。为了揭示马铃薯X病毒属抗性1（JAX 1）所需的jacalin型凝集素（jacalin-type lectin）所赋予的抗性特征，我们分析了抗性破坏变体以找到参与抗性的病毒组分。我们采用嫁接介导的接种，一种高压病毒接种方法，以获得马铃薯X病毒（PVX）变异体，可以克服JAX 1介导的抗性。变异体的全基因组测序表明，PVX编码的复制酶的甲基转移酶结构域中的单个氨基酸负责这种耐药性破坏特性。将氨基酸取代重新引入无毒野生型PVX足以克服JAX 1介导的抗性。这些结果表明，病毒复制酶参与JAX 1介导的抗性。决定抗性破坏特性的残基在马铃薯X病毒中高度保守，表明该残基在马铃薯X病毒-JAX 1相互作用中的一般作用。
Lectin-mediated resistance (LMR) has been suggested to comprise an uncharacterized branch of antiviral plant innate immunity. To unveil the feature of resistance conferred by jacalin-type lectin required for potexvirus resistance 1 (JAX1), a recently isolated LMR gene against potexviruses, we analyzed the resistance-breaking variants to find the viral component involved in resistance. We employed grafting-mediated inoculation, a high-pressure virus inoculation method, to obtain Potato virus X (PVX) variants that can overcome JAX1-mediated resistance. Whole-genome sequencing of the variants suggested that a single amino acid in the methyl transferase domain of the replicase encoded by PVX is responsible for this resistance-breaking property. Reintroduction of the amino-acid substitution to avirulent wild-type PVX was sufficient to overcome the JAX1-mediated resistance. These results suggest that viral replicase is involved in JAX1-mediated resistance. The residue that determines the resistance-breaking properties was highly conserved among potexviruses, suggesting a general role of the residue in potexvirus-JAX1 interactions.