Comparative genomics reveals unique wood‐decay strategies and fruiting body development in the Schizophyllaceae
Résumé
Agaricomycetes are fruiting body‐forming fungi that produce some of the most efficient enzyme systems to degrade wood. Despite decades‐long interest in their biology, the evolution and functional diversity of both wood‐decay and fruiting body formation are incompletely known.
We performed comparative genomic and transcriptomic analyses of wood‐decay and fruiting body development in Auriculariopsis ampla and Schizophyllum commune (Schizophyllaceae), species with secondarily simplified morphologies, an enigmatic wood‐decay strategy and weak pathogenicity to woody plants.
The plant cell wall‐degrading enzyme repertoires of Schizophyllaceae are transitional between those of white rot species and less efficient wood‐degraders such as brown rot or mycorrhizal fungi. Rich repertoires of suberinase and tannase genes were found in both species, with tannases restricted to Agaricomycetes that preferentially colonize bark‐covered wood, suggesting potential complementation of their weaker wood‐decaying abilities and adaptations to wood colonization through the bark. Fruiting body transcriptomes revealed a high rate of divergence in developmental gene expression, but also several genes with conserved expression patterns, including novel transcription factors and small‐secreted proteins, some of the latter which might represent fruiting body effectors.
Taken together, our analyses highlighted novel aspects of wood‐decay and fruiting body development in an important family of mushroom‐forming fungi.