Molecular analysis of nucleocytoplasmic signaling pathways in plant cellular immunity

• Applicant: Professor Dr. Marcel Wiermer
• Subject Area: Plant Biochemistry and Biophysics
• Term: from 2011 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 206673514

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.

• DFG Programme: Research Grants