Lichen symbioses are thought to be stabilized by the transfer of fixed carbon from a photosynthesizing symbiont to a fungus. In other fungal symbioses, carbohydrate subsidies correlate with reductions in plant cell wall-degrading enzymes, but whether this is true of lichen fungal symbionts (LFSs) is unknown. We predicted genes encoding carbohydrate-active enzymes (CAZymes) and sugar transporters in 46 genomes from the Lecanoromycetes, the largest extant clade of LFSs. All LFSs possess a robust CAZyme arsenal including enzymes acting on cellulose and hemicellulose, confirmed by experimental assays. However, the number of genes and predicted functions of CAZymes vary widely, with some fungal symbionts possessing arsenals on par with well-known saprotrophic fungi. These results suggest that stable fungal association with a phototroph does not in itself result in fungal CAZyme loss, and lends support to long-standing hypotheses that some lichens may augment fixed CO2 with carbon from external sources.

The data provided are intermediate results from genome annotations performed with funannotate, phylogenomic trees calculated with phylociraptor and additional settings and configuration files used to run different analyses steps. The files are processed in a comparative genomic analysis pipeline (https://github.com/reslp/LFS-cazy-comparative) to create perform the final analyses and create figures for the publication.

They should be used together with the comparative genomic pipeline used in the paper, which is available here: https://github.com/reslp/LFS-cazy-comparative.

If this pipeline is set up correctly, the data provided here should be downloaded automatically.