Molecular functions of nuclear pore complex proteins in plant defense signal transduction and gene expression

• Applicant: Professor Dr. Marcel Wiermer
• Subject Area: Organismic Interactions, Chemical Ecology and Microbiomes of Plant Systems
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 434260194

The nuclear envelope acts as a protective compartment boundary for the genome and provides eukaryotic cells with an important means to control the specificity and timing of signaling events and gene expression. Nuclear pore complexes, composed of nucleoporin proteins (NUPs), perforate the nuclear envelope and have emerged as a strategic platform for regulating plant cellular responses to microbial pathogen attack. However, the detailed molecular mechanisms and the functional role of individual nucleoporins in regulating nucleocytoplasmic signal relay and gene expression outputs in plant immunity are far from comprehensive. Recent work in our laboratory shows that the Arabidopsis nucleoporins NUP88, NUP96 and NUP160 affect plant immune responses by different molecular mechanisms. Both NUP96 and NUP160 are involved in nuclear mRNA export and essential for full expression of certain defense genes. In contrast, NUP88 selectively attenuates nuclear export of important defense regulatory proteins to promote their accumulation inside the nucleoplasm. I therefore propose two subprojects. One project will focus on the functional role of NUP88 in plant immunity. We will test the hypothesis that NUP88 selectively modulates multiple distinct defense signaling pathways by regulating nuclear concentrations of unknown immune regulatory proteins. Their identification and subsequent detailed functional characterization in plant defense signal transduction is a major goal of this project. The other project will address how NUP96 and NUP160 mechanistically influence the expression and mRNA export of specific immune response genes. We will investigate which mRNA export pathways are controlled by these two nucleoporins and address transport-independent but chromatin-related functions in the regulation of defense gene expression. This may reveal new targets and molecular mechanisms to modulate plant disease resistance for future sustainable food security.

• DFG Programme: Research Grants