Chiang Mai Journal of Science

Ganoderma lucidum is a medicinal mushroom with a broad spectrum of secondary metabolites with antibacterial and antiviral properties that can be leveraged as lead compounds for drug development. The fungus is known to have two distinct forms corresponding to different culture conditions that result in kidney and antler shapes. Upon culturing in a dark and enclosed environment with elevated CO₂ concentration, the fungus adopts an antler-shaped fruiting body instead of the typical kidney-shaped morphology. The mechanism of G. lucidum phenotypic alteration yet to be understood. By using the RNA-Seq transcriptome de novo assembly approach, the differential gene expression (DGE) profiles during the morphogenesis of the two fungal shapes revealed that the fungal hydrophobin gene SC3 was up-regulated for the production of antler-shaped fruiting body. The analysis also indicated up-regulation of the pentose phosphate pathway (PPP) as the key metabolic pathway for converting glucose into various types of sugars for the survival of the fungus. Numerous unigenes for the biosynthesis of triterpenoids, which include the key enzymes of lanosterol synthase (LS), cytochromes P450 (P450) and uridine diphosphate glycosyltransferases (UGTs) genes were also identified and significantly up-regulated from the DGE analysis associated with the morphogenesis of antler-shaped G. lucidum.