Deep sequencing of the Sanghuangporus vaninii transcriptome reveals dynamic landscapes of candidate genes involved in the biosynthesis of active compounds

Abstract

The medicinal fungus Sanghuang produces diverse bioactive compounds and is widely used in Asian countries. However, little is known about the genes and pathways involved in the biosynthesis of these active compounds. Based on our previous study providing Sanghuangporus vaninii genomic information, the transcriptomes of MY (mycelium), OY (1-year-old fruiting bodies), and TY (3-year-old fruiting bodies) were determined in this study. A significant number of genes (4774) were up- or downregulated between mycelium and fruiting bodies, but only 1422 differentially expressed genes were detected between OY and TY. 138 genes encoding P450s were identified in the fungal genome and grouped into 25 P450 families; more than 64% (88) of the genes were significantly differentially expressed between the mycelium and fruiting body, suggesting that these P450s are involved in fungal sexual development. Importantly, the expression of genes involved in bioactive compound (triterpenoids, polysaccharides, and flavonoids) biosynthesis in asexual (cultured with solid and liquid media) and sexual stages was explored and combined with transcriptome and quantitative PCR analyses. More genes involved in the biosynthesis of bioactive compounds were expressed more highly in mycelium than in fruiting bodies under liquid medium culture compared with solid medium culture, which was consistent with the yields of different bioactive compounds, suggesting that liquid fermentation of S. vaninii Kangneng can be used to obtain these bioactive compounds. A comprehensive understanding of the genomic information of S. vaninii will facilitate its potential use in pharmacological and industrial applications.