Genomic and transcriptomic analysis and prediction of genes involved in polysaccharide and bioactive secondary metabolites in wild Flammulina filiformis

Flammulina filiformis (=Asian “F.velutipes”) is a popular commercial edible mushroom. The medicinal effects of its bioactive compounds such as polysaccharides and sesquiterpenoids have been reported, but the biosynthesis of these components is not fully unknown. In this study, we sequenced a wild strain genome of F. filiformis Liu 355 and predicated the biosynthetic gene clusters (BGCs). We also performed a comparative transcriptomic analysis between wild and cultivar strain and among different development stages of wild strain of F. filiformis to profile candidate genes expression. In this study, the genome of the F. filiformis was 35.01 M bp in length and annotated with 10396 gene models.12 putative terpeniod gene clusters were predicted. 12 sesquiterpenes synthase genes belonged to four different groups and two type I PKS (polyketide synthase) gene clusters were identified from F. filiformis genome. Expression profiles of candidate genes were verified by qPCR in different tissues and different strains of F. filiformis. This study expends our knowledge for biology of F. filiformis and provides valuable clues for identifying candidate genes involved in the biosynthesis of polysaccharide and terpenoid bioactive compounds.