Symbioses have been fundamental to colonization of terrestrial ecosystems by plants and their evolution. Emergence of the ancient arbuscular mycorrhizal symbiosis was followed by the diversification of alternative intracellular symbioses, such as the ericoid mycorrhizae (ErM). We aimed at understanding how these diversifications occurred. We sequenced the genomes of ErM-forming liverworts, and reconstituted symbiosis under laboratory conditions. We demonstrated the existence of a nutrient-regulated symbiotic state that enables ErM and underlies intracellular colonization of plant tissues. Comparative transcriptomic analyses identified an ancestral gene module associated with intracellular symbiosis beyond ErM. Genetic manipulations in the liverwort Marchantia paleacea, phylogenetics and transactivation assays demonstrated its essential function for intracellular symbiosis. We conclude that plant have maintained, and convergently recruited, an ancestral gene module for intracellular symbioses.

Symbioses have been fundamental to colonization of terrestrial ecosystems by plants and their evolution. Emergence of the ancient arbuscular mycorrhizal symbiosis was followed by the diversification o...

Land plants include angiosperms, gymnosperms, 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 analyzing the diversity of fern immune receptors. A collection of fern species was inoculated with a diverse set of filamentous 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 putative non-host resistance and more 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 sub-families lost in flowering plants. These findings provide insights into disease resistance evolution and open promising perspectives for crop protection strategies.

The success of plants on land has been enabled by mutualistic intracellular associations with microbes for 450 million years (Delaux and Schornack 2021). Because of their intracellular nature, the est...

A super-pangenome analysis incorporating 123 newly sequenced bryophyte genomes reveals that bryophytes exhibit a larger number of unique and lineage-specific gene families than vascular plants.

Arbuscular mycorrhiza (AM) with soilborne Glomeromycota fungi was pivotal in the conquest of land by plants almost half a billion years ago. In flo...