Putative members of the Arabidopsis Nup107-160 nuclear pore sub-complex contribute to pathogen defense.
Putative members of the Arabidopsis Nup107-160 nuclear pore sub-complex contribute to pathogen defense.
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DOI：
10.1111/j.1365-313x.2012.04928.x
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发表时间：
2012-06
期刊：
影响因子：
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通讯作者：
M. Wiermer;Y. Cheng;Julia Imkampe;Meilan Li;Dongmei Wang;V. Lipka;Xin Li
中科院分区：
文献类型：
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作者：
M. Wiermer;Y. Cheng;Julia Imkampe;Meilan Li;Dongmei Wang;V. Lipka;Xin Li
在真核细胞中，由核孔蛋白 (Nups) 组成的核孔复合物 (NPC) 介导外部刺激转导至细胞核以诱导转录并输出 mRNA 以在细胞质中进行翻译。我们之前报道过拟南芥 MOS3 编码脊椎动物 Nup96 的同源物，是植物免疫和组成型抗性所必需的，这些免疫和组成型抗性是由失调的 Toll 白细胞介素 1 受体/核苷酸结合/富含亮氨酸重复序列 (TNL) 型 R 基因 snc1 介导的。在脊椎动物中，Nup96 是保守的 Nup107-160 核孔亚复合体的组成部分，与免疫相关 mRNA 输出有关。在这里，我们使用反向遗传学方法来检查植物免疫中预测的拟南芥 Nup107-160 复合体的额外亚基的需求。我们发现，在八个假定的复合体成员中，除了 MOS3 之外，只有 Nup160 或 Seh1 缺陷的植物的基础抗性受损。 snc1突变体的组成型抗性和TNL型R基因介导的免疫也依赖于功能性Nup160，并且对Seh1有部分需求。相反，卷曲线圈型免疫受体赋予的抗性在很大程度上独立于这两个基因而发挥作用，证明了对植物防御信号传导的特定贡献。我们的功能分析进一步表明，nup160 和 seh1 的缺陷导致 Poly(A) mRNA 的核积累，并且就 nup160 而言，EDS1 大量消耗，EDS1 是基础和 TNL 触发耐药性的关键正调节因子。这些发现表明，Nup160 是拟南芥中核 mRNA 输出和 EDS1 条件抗性途径完全表达所必需的。
In eukaryotic cells, transduction of external stimuli into the nucleus to induce transcription and export of mRNAs for translation in the cytoplasm is mediated by nuclear pore complexes (NPCs) composed of nucleoporin proteins (Nups). We previously reported that Arabidopsis MOS3, encoding the homolog of vertebrate Nup96, is required for plant immunity and constitutive resistance mediated by the de-regulated Toll interleukin 1 receptor/nucleotide-binding/leucine-rich repeat (TNL)-type R gene snc1. In vertebrates, Nup96 is a component of the conserved Nup107-160 nuclear pore sub-complex, and implicated in immunity-related mRNA export. Here, we used a reverse genetics approach to examine the requirement for additional subunits of the predicted Arabidopsis Nup107-160 complex in plant immunity. We show that, among eight putative complex members, beside MOS3, only plants with defects in Nup160 or Seh1 are impaired in basal resistance. Constitutive resistance in the snc1 mutant and immunity mediated by TNL-type R genes also depend on functional Nup160 and have a partial requirement for Seh1. Conversely, resistance conferred by coiled coil-type immune receptors operates largely independently of both genes, demonstrating specific contributions to plant defense signaling. Our functional analysis further revealed that defects in nup160 and seh1 result in nuclear accumulation of poly(A) mRNA, and, in the case of nup160, considerable depletion of EDS1, a key positive regulator of basal and TNL-triggered resistance. These findings suggest that Nup160 is required for nuclear mRNA export and full expression of EDS1-conditioned resistance pathways in Arabidopsis.