Bonus remark: Maximum permissive levels for ericoid mycorrhizae are achieved in a nutrient condition with a low supply of both phosphate and nitrogen. This supports that this mutualistic interaction provides stress resilience to plants and fungi under extreme nutrient deficiency conditions.

This analysis identified orthogroups in leafy liverworts upregulated during ericoid mycorrhizae that
had ortholog genes upregulated during arbuscular mycorrhizae in other plant species, including genes
that enable the intracellular accommodation of microbial endophytes.

Comparative transcriptomics provided empirical support for the involvement of genes in the common symbiosis
signaling pathway, infectosome formation, and nutrient exchange during ericoid mycorrhizae.

With this approach, we identified both a permissive and a
restrictive condition for the establishment of ericoid mycorrhizae.

To test whether these genes respond to ericoid mycorrhizae, we established an experimental system to assess transcriptomic responses during symbiosis in variable nutrient environments.

The leafy liverworts genomes harbor a suite of genes with well-established functions in plant endosymbioses, including genes involved in the common symbiosis signaling pathway, infectosome formation, and nutrient exchange.

To contribute to this understudied field, we sequenced the genomes of two leafy liverworts from the order Jungermanniales, Calypogeia fissa and Solenostoma infuscum.

It has long been hypothesized that (1) ericoid mycorrhizae evolved from arbuscular mycorrhizae, and (2) that ericoid mycorrhizae contribute to the mobilization and bioavailability of phosphate and nitrogen in the soil. Despite its relevance, little is known about ericoid mycorrhizae.

Ericoid mycorrhizae are of extreme ecological relevance, as they are thought to have underpinned the evolution of both the Ericaceae family of angiosperms and leafy liverworts while also facilitating the colonization of nutrient-poor
soils (low in phosphate and nitrogen) by these plants.

Mycorrhizae have been critical for the evolution of land plants and the colonization of terrestrial ecosystems. The emergence of the ancient arbuscular mycorrhizae was followed by the diversification of other mycorrhizal
types, including the ericoid mycorrhizae.

www.science.org/doi/10.1126/...