RESUMO
Inonotus obliquus is a pathogenic fungus found in living trees and has been widely used as a traditional medicine for cancer therapy. Although lignocellulose-degrading enzymes are involved in the early stages of host infection, the parasitic life cycle of this fungus has not been fully understood. In this study, we aimed to investigate the activities of laccase (Lac), manganese peroxidase (MnP), and lignin peroxidase (LiP) from I. obliquus cultivated in Kirk's medium. The fungus was subjected to genome sequencing, and genes related to wood degradation were identified. The draft genome sequence of this fungus comprised 21,203 predicted protein-coding genes, of which 134 were estimated to be related to wood degradation. Among these, 47 genes associated with lignin degradation were found to have the highest number of mnp genes. Furthermore, we cloned the cDNA encoding a putative MnP, referred to as IoMnP1, and characterized its molecular structure. The results show that IoMnP1 has catalytic properties analogous to MnP. Phylogenetic analysis also confirmed that IoMnP1 was closely related to the MnPs from Pyrrhoderma noxium, Fomitiporia mediterranea, and Sanghuangporus baumii, which belong to the same family of Hymenochaetaceae. From the above results, we suggest that IoMnP1 is a member of MnPs.
RESUMO
Inonotus obliquus is a medicinal fungus in the family Hymenochaetaceae and commonly known as chaga. The sclerotium of this fungus has been used as a traditional medicine for long time. In this study, we present the mitochondrial genome sequence of I. obliquus. The mitochondrial DNA (mtDNA) is 119,110 base pairs in length and contained genes for 58 Open reading frames, 2 ribosomal RNAs, and 30 transfer RNAs. Consequently performed phylogenetic analysis indicates that this fungus is closely related to Sanghuangporus sanghuang which belongs to the same family Hymenochaetaceae. We first reported about the complete mitochondrial genome of fungi belonging to the genus Inonotus.
