rDNA ITS identification and genomic analysis of Calvatia gigantea, the first sequenced species of Lycoperdaceae

Abstract:

[Background] The puffball mushroom is commonly used traditional medicinal edible fungus, which has multiple pharmacological effects, including antimicrobial, anti-inflammatory, anti-tussive, anti-cancer and suppressing cell growth effects. So far, most of the researches on puffball mushrooms have been focused on extraction and pharmacological effect of their bioactive agents. Nevertheless, little is known about the genomic information of puffball mushrooms. [Objective] To acquire genomic information of puffball mushrooms and mine protein-encoding gene of potential application in industry. [Methods] A combination of Illumina and PacBio sequencing technologies was used for genome sequencing, and analysis of genome structure and gene annotation were performed against multiple database, including GO. The sequenced puffball mushroom was subjected to ITS identification, while CAZymes and secondary metabolite biosynthetic gene clusters were identified using dbCAN and antiSMASH, respectively. [Results] The acquired puffball genome was 46.04 Mb in size, encoding 11 903 proteins including GO-annotated genes. Based on the genomic information, the puffball species was identified as Calvatia gigantea using ITS (Internal Transcribed Spacer). A total of 25 genes related to terpene and ergosterol biosynthetic pathway were analyzed, while 317 CAZymes and 18 secondary metabolite biosynthetic gene clusters were identified. In addition, an alpha-amylase from CAZymes was characterized as a potential secretory, tannin-resistant α-amylase. [Conclusion] This study supplied the first sequenced puffball mushroom, and found a potential tannin-resistant α-amylase and multiple new secondary metabolite biosynthetic gene clusters. This study will supply important basic genetic information for genetic evolution and functional researches of puffball mushrooms, their further application in food industry, and development of secondary metabolites of pharmaceutical value.