Comparative mitogenomics reveals large-scale gene rearrangements in the mitochondrial genome of two Pleurotus species

In the present study, we assembled the mitogenomes of Pleurotus citrinopileatus and Pleurotus platypus. The circular mitogenome of the two Pleurotus species comprises a set of 14 conserved protein-encoding genes (PEGs), 2 RNA genes (small subunit ribosomal RNA and large subunit ribosomal RNA), and 24 tRNAs, with sizes of 60,694 and 73,807 bp, respectively. They contain 4 and 10 introns with 3 and 10 intronic open reading frames (ORFs), respectively. Thirteen position classes (Pcls) of introns were found in the cox1 gene of four Pleurotus species. The number and class of Pcl varied among different Pleurotus species, indicating that numerous events of loss and gain occurred during evolution of Pleurotus. Comparative mitogenomic and collinearity analyses reveal that large-scale gene rearrangements may have occurred during the evolution of Pleurotus citrinopileatus and Pleurotus platypus, including gene rearrangements and inversions, which may be related to the observed high amounts of repetitive DNA elements (5.62 and 5.45%, respectively). Phylogenetic analysis based on concatenated mitochondrial protein sequences reveals that concatenated mitochondrial genes are suitable as molecular markers for phylogenetic analysis. This serves as the first report on large-scale rearrangements in the mitochondria of the genus Pleurotus, thereby improving our understanding of the evolution of the Pleurotus genus and other macrofungi.