Molecular analysis of nucleocytoplasmic signaling pathways in plant cellular immunity

植物细胞对微生物感染的免疫应答依赖于通过核孔复合物（NPCs）穿越核膜（NE）的动态信号事件。然而，促进细胞质和核质在植物免疫中的空间通讯的分子机制和成分却知之甚少。我们提出的研究方向是了解宿主核输入受体MOS6 （Importin3）和Nup107-160核孔亚复合物的三个成员，Nup160， Seh1和MOS3 （Nup96）的分子功能，它们对拟南芥的抗病至关重要，分别涉及防御相关的核蛋白输入和mRNA输出。特别是，我们的目标是识别和分子表征MOS6货物蛋白和参与疾病反应信号的相互作用伙伴，使用植物中的生化亲和纯化方法，并解决进口蛋白家族成员在植物防御中的潜在功能冗余。第二个研究项目将分析Nup107-160复合体的核机会突变体在防御所需mrna特定亚群输出中的缺陷，并表征Nup107-160复合体成员在调节植物免疫中的功能关系。总之，这些研究将揭示通过核细胞质运输对植物细胞免疫反应的复杂调控的重要信息。这应该为如何修改植物免疫系统以改善植物保护提供见解。

Plant cellular immune responses against microbial infection depend on dynamic signaling events across the nuclear envelope (NE) through nuclear pore complexes (NPCs). However, the molecular mechanisms and components that facilitate spatial communication between the cytoplasm and the nucleoplasm in plant immunity are poorly understood. Our proposed research efforts are directed towards understanding the molecular function of the host nuclear import receptor MOS6 (Importin 3) and three members of the Nup107-160 nuclear pore sub-complex, Nup160, Seh1 and MOS3 (Nup96), that are essential for disease resistance in Arabidopsis and implicated in defense-related nuclear protein import and mRNA export, respectively. In particular, we aim to identify and molecularly characterize MOS6 cargo proteins and interacting partners involved in disease response signaling, using a biochemical in planta affinity purification approach and to address potential functional redundancy between Importin  family members in plant defense. The second research project will analyze nucleoporin mutants of the Nup107-160 complex for defects in the export of specific subsets of mRNAs required for defense and characterize the functional relationship of Nup107-160 complex members in regulating plant immunity. Together, these studies will reveal important information on the intricate regulation of cellular plant immune responses by nucleocytoplasmic transport. This should provide insights as to how the plant immune system can be modified to improve plant protection.