Complete mitochondrial genome of Laetiporus ailaoshanensis (Laetiporaceae, Basidiomycota): features, evolution, and phylogeny

Laetiporus ailaoshanensis is a fungus within the Laetiporaceae family that causes brown rot in wood through its ability to degrade lignocellulose. However, the mitochondrial genome (mitogenome) of members of the genus Laetiporus has not been extensively investigated. After complete sequencing and assembly, we annotated and characterized the mitogenome of L. ailaoshanensis and selected Polyporales species for comparative analyses, including gene composition and number, AT/GC content, and skew, codon usage, genetic distance, nonsynonymous and synonymous substitution rates (Ka and Ks), intron dynamics, and phylogenetics. The mitogenome of L. ailaoshanensis was found to contain 117,203 bp and 15 protein-coding genes (PCGs), two ribosomal RNA (rRNA) genes, 25 transfer RNA (tRNA) genes, and 12 introns. Phylogenetic analysis based on mitogenomes further confirmed its phylogenetic relationships within Polyporales. Two Laetiporus species were grouped together with Wolfiporia cocos on the same branch and had a high level of support. This study represents the first report on the mitogenome of L. ailaoshanensis, filling an important gap in the mitogenome database of the Laetiporaceae and providing a cornerstone for comparative genomics within this clade. Additionally, in phylogenetic analysis, the highly supported topological structure clearly placed Laetiporus and Wolfiporia on the same branch, which laid a solid foundation for further clarification of taxonomic classification.