Exploring fern pathosystems and immune receptors to bridge gaps in plant immunity

Castel, B.; Baker, M.; Keller, J.; Martinez, Y.; Bonhomme, M.; Delaux, P.-M.; Jacquet, C.

doi:10.1101/2025.03.18.643875

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bioRxiv · 10.1101/2025.03.18.643875

Exploring fern pathosystems and immune receptors to bridge gaps in plant immunity

Castel, B.·Baker, M.·Keller, J.·Martinez, Y.·Bonhomme, M.·Delaux, P.-M.·Jacquet, C.

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Abstract

Land plants include angiosperms, bryophytes, lycophytes and ferns, each of which may deploy distinct strategies to resist pathogens. Here, we investigate fern-pathogen interactions by characterizing novel pathosystems and analysing the diversity of fern immune receptors. A collection of fern species was inoculated with a diverse set of microbes, and disease symptoms were assessed. We further leveraged published genome mining tools to analyse the diversity of RECEPTOR-LIKE KINASES, RECEPTOR-LIKE PROTEINS (RLKs/RLPs) and NUCLEOTIDE-BINDING AND LEUCINE-RICH REPEATS (NLRs), along with key immune signalling components, in ferns. Our results reveal that ferns exhibit a range of responses to pathogens, including non-host resistance and specific resistance mechanisms. Among ten ferns tested, Pteris vittata displays the broadest spectrum of pathogen compatibility. Genome mining indicates that ferns encode a diverse repertoire of putative immune receptors, antimicrobial peptides and mediators of systemic acquired resistance. Ferns possess numerous RLKs/RLPs, resembling those required for cell-surface immunity in angiosperms. They also encode diverse NLRs, including a previously undescribed class with a disordered N-terminal domain, termed disN-NLR. These findings provide insights into disease resistance evolution and open promising perspectives for crop protection strategies.

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Castel, B., Baker, M., Keller, J., Martinez, Y., Bonhomme, M., Delaux, P.-M., Jacquet, C.. 2025-03-19. Exploring fern pathosystems and immune receptors to bridge gaps in plant immunity. https://doi.org/10.1101/2025.03.18.643875

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