De novo assembly of Auricularia polytricha transcriptome and discovery of genes involved in the degradation of lignocellulose

Auricularia polytricha belonging to Basidiomycota has the ability to degrade lignocellulose. However, there has been no resource in public databases examining the transcriptome of A. polytricha. In this study, high-throughput sequencing platform BGISEQ-500 was used to generate large amount of transcript sequences from A. polytricha for gene discovery and molecular marker development. A total of 28,102 unigenes were discovered from the assembly of clean reads. In addition, functional categorization of the gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) metabolic pathways revealed several important biological processes. GO annotation analysis presented 47 categories, with the major subcategories being catalytic activity, binding, cellular process, metabolic process, and cell. Among the five functional categories and 21 subcategories of processes discovered from KEGG, global and overview maps, carbohydrate metabolism, transport, and catabolism are the main subcategories. Furthermore, among the unigenes related to lignocellulosic degradation discovered by KEGG pathway enrichment analysis, 2, 5, and 16 unigenes in de novo assembly of A. polytricha transcriptome were found to relate to cellulose, hemicellulose, and lignin degradation, respectively. The study provided valuable information on the degradation of lignocellulose to facilitate research on the degradation mechanism, molecular marker, functional research, gene mapping, and other multigenomic studies of species containing lignocellulose.