De Novo Transcriptome Analysis of the Willow Bracket Medicinal Mushroom Phellinus igniarius (Agaricomycetes) by RNA Sequencing.

Abstract

Phellinus igniarius has been widely used as traditional herbal medicine in China, Korea, Japan, and other Asian countries for centuries. To gain a molecular understanding of this fungus, Illumina high-throughput technology was used to sequence and analyze the transcriptome of Ph. igniarius, and 11,847 unigenes were obtained. Additionally, based on similarity search with known proteins, unigenes were annotated with gene descriptions, gene ontology (GO), and clusters of orthologous groups (COG). Based on the GO annotation, a total of 6983 unigenes could be assigned to one or more terms, which were categorized into 39 functional groups under three main divisions (biological process, cellular component and molecular function). A total of 2315 Ph. igniarius unigenes were associated with 124 unique Kyoto Encyclopedia of Genes and Genomes pathways. A total of 832 simple sequence repeats were identified in these unigenes. In addition, nine candidate genes involved in laccases were discovered, 17 candidate genes involved in the biosynthesis of triterpenoid were identified and were worthy for further investigation. This is the first study to conduct transcriptome analyses on Ph. igniarius, which lays a basis for further functional genomics studies of Ph. igniarius.