Molecular Dissection of an Immune Receptor Signaling Mechanism

Plants rely on an innate immune system to fight disease caused by pathogens. We study resistance and cell death pathways in Arabidopsis and tobacco that are triggered by intracellular (NLR) receptors, recognizing specific pathogen virulence factors (effectors). Two distinctive NLR downstream signaling branches are controlled by different EDS1 (non-NLR) protein complexes with specific sets of HeLo-domain signaling NLRs. The aim and scope of this project is to investigate one of these immunity branches - that of EDS1 with PAD4 and HeLo-NLRs of the ADR1 family - using Arabidopsis and tobacco mutants and protein structural variants in ‘in vivo’ immunity and cell death reconstitution assays. A  further aim of the project will be to identify plant small molecules that modify and/or activate PAD4 through targeted metabolite profiling of resting and induced leaf tissue extracts and analysis of small molecule binding to PAD4 alone or together with its signaling partners. The goal of this project is therefore to understand better the molecular decision-making process in plant immunity.