Figure 4: Distribution of symbiosis-upregulated genes of clusters I to VI into functional categories, including MiSSPs and nonsecreted orphan genes (no KOG).

MiSSPs represent 16% of the symbiosis-upregulated transcripts in cluster V, a significant enrichment compared to their percentage in the total gene repertoire (i.e., 2%). CAZyme, carbohydrate-active enzymes; FOLyme, fungal oxidative lignin-degrading enzymes.