The putative kinase substrate MUSE7 negatively impacts the accumulation of NLR proteins
The putative kinase substrate MUSE7 negatively impacts the accumulation of NLR proteins
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DOI：
10.1111/tpj.13454
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发表时间：
2017-03-01
期刊：
影响因子：
7.2
通讯作者：
Li, Xin
中科院分区：
文献类型：
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作者：
Johnson, Kaeli C. M.;Zhao, Jin;Li, Xin
严格调节植物的免疫信号是必要的，以使快速响应病原体的攻击，没有虚假的防御激活。为了鉴定与植物免疫有关的基因，对自身免疫snc1 （npr1的抑制因子，构成型1）突变体的增强子进行了正向遗传筛选。snc1突变体在编码nod样受体（NLR）蛋白的基因中包含一个功能获得突变。分离的muse7（突变体，snc1增强，7）突变体显示在野生型样mos4 (snc1修饰子，4)snc1背景中赋予自身免疫表型的逆转。定位克隆表明，MUSE7编码一个进化上保守的激酶底物，功能未知。muse7单突变体对紫丁香假单胞菌的抗性增强。番茄DC3000。虽然SNC1的转录没有增强，但SNC1蛋白积累的升高与muse7的突变有关。另外两个NLR蛋白的积累，RPS2（对丁香假单胞菌2的抗性）和RPM1（对丁香假单胞菌pv的抗性）。在博物馆植物中也观察到MACULICOLA 1)。虽然蛋白酶体介导的NLR蛋白降解在植物免疫中是一个被充分研究的事件，但MUSE7与该途径的选定组分之间没有发现相互作用。该研究证实了MUSE7通过负向影响NLR积累来调节植物免疫应答的作用，为未来在其他物种中研究MUSE7同源物提供了有益的依据。
Stringent modulation of immune signaling in plants is necessary to enable a rapid response to pathogen attack without spurious defense activation. To identify genes involved in plant immunity, a forward genetic screen for enhancers of the autoimmune snc1 (suppressor of npr1, constitutive 1) mutant was conducted. The snc1 mutant contains a gain-of-function mutation in a gene encoding a NOD-like receptor (NLR) protein. The isolated muse7 (mutant, snc1-enhancing, 7) mutant was shown to confer a reversion to autoimmune phenotypes in the wild-type-like mos4 (modifier of snc1, 4) snc1 background. Positional cloning revealed that MUSE7 encodes an evolutionarily conserved putative kinase substrate of unknown function. The muse7 single mutants display enhanced resistance to the bacterial pathogen Pseudomonas syringae pv. tomato DC3000. While transcription of SNC1 is not enhanced, elevated SNC1 protein accumulation is associated with mutations in muse7. Accumulation of two additional NLR proteins, RPS2 (RESISTANCE TO PSEUDOMONAS SYRINGAE 2) and RPM1 (RESISTANCE TO PSEUDOMONAS SYRINGAE pv. MACULICOLA 1), was also observed in muse7 plants. Although proteasome-mediated degradation of NLR proteins is a well studied event in plant immunity, no interactions were detected between MUSE7 and selected components of this pathway. This study has demonstrated a role for MUSE7 in modulating plant immune responses through negatively affecting NLR accumulation, and will benefit future studies of MUSE7 homologs in other species.