Molecular analysis of apoplastic effector-mediated suppression of PTI signaling

01/02/2019 to 31/01/2022

Plant innate immunity mediated through membrane-bound pattern recognition receptors (PRRs) is instrumental to protection against microbial infections. However, host-adapted plant pathogenic fungi and oomycetes have evolved apoplastic effectors that manipulate plant extracellular functions in order to establish infection. Recently, we identified a conserved effector protein SCP8 from Verticillium dahliae, a fungal pathogen with a broad host range. SCP8 suppresses some immunity-associated defenses in Arabidopsis mediated through activation of LRR-RK and LRR-RP-type PRRs. Here, we propose to identify structural motifs within SCP8 that are required for its immunosuppressive activity. We further propose to employ sophisticated protein-protein interaction technologies and forward genetic screens to identify putative SCP8-interacting plant proteins involved in SCP8-mediated immune suppression. Our work aims at gaining a molecular understanding of how an apoplastic fungal effector may manipulate plant host immune activation through interference with components of the plant immune system that are shared among certain, but not all PRRs. This work may demonstrate the potential of using microbial effectors to decipher plant immune signal transduction cascades.