Invited Presenter

Chris Blackman^1,3, Tian Lei^2,3, Margaret Balcerzak³, Alexia Aguayo Limon^2,3, Malaika Zarrouki^2,3, Darrell Desveaux¹, Rajagopal Subramaniam³
1. Cell & Systems Biology, University of Toronto, 27 King’s College Cir, Toronto, ON, M5S 1A1
2. Department of Biology, Carleton University, 1125 Colonel By Dr, Ottawa, ON, K1S 5B6
3. Ottawa Research and Development Centre, Agriculture and Agrifood Canada, 960 Carling Ave., Ottawa, ON, K1A 0C6
Corresponding Author: Chris Blackman, chris.bonner@mail.utoronto.ca

Blackman, Chris

chris.bonner@mail.utoronto.ca

The Fusarium sambucinum species complex (FSAMSC) comprises prominent phytopathogenic fungi that collectively place a severe burden on global agriculture. Understanding the interaction between host plants and fungi is crucial to delineate mechanisms of plant defence and mitigate agricultural losses. Many phytopathogens deploy suites of secreted proteins, called effectors, to modulate host immunity and promote colonization; however, fungal phytopathogenic effectors are poorly understood in comparison to those of bacterial phytopathogens. To promote characterization of FSAMSC effectors, we developed a pan-genomic effectome for this species complex using a combination of bioinformatics tools. Our pipeline led to the prediction of 125,777 candidate-secreted effector proteins (CSEPs) from 195 isolates, including 235 conserved (“core”) effector families. A subset of core families demonstrated diversifying selection, and we hypothesized that these epitopes may be critical to host recognition and are thus likely to interact with host defence factors. We developed structural comparisons to known fungal effectors using AlphaFold and Foldseek, and used multiple virulence assays to demonstrate effector-like, and immune-eliciting function for a subset of conserved effectors. Host interaction partners of fungal effectors will be identified via proximity-based labelling with TurboID, to ultimately resolve a plant-pathogen interaction network.

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