Abstract
Triterpenoid, the active ingredient in the dried sclerotia of Wolfiporia cocos, has a variety of pharmacological effects. The focus of this research was the cell engineered bacteria modified for triterpenoid biosynthesis, and we aimed to identify the key genes involved in triterpenoid biosynthesis and their roles. Two monospora strains, H and L, were selected from the sexually propagated progeny of W. coco strain 5.78, and their mycelia were cultured for 17, 34, and 51 days. Metabolite analysis showed that there were significantly more down-regulated metabolites of the two strains at three different culture periods than up-regulated metabolites. KEGG indicated that the differential metabolites were mainly concentrated in sterol biosynthesis and ABC transport. STEM analysis suggested that polysaccharide synthesis and accumulation might be greater in the L strain than the H strain. The correlation analysis of DEGs and differential metabolites between the two strain groups showed that erg11 and FDPS, which were closely positively correlated with differential metabolites associated with triterpenoids, were highly expressed in the L strain. This result suggested that the high expression of some genes in the L strain might shunt precursor substances of triterpenoids, which was the possible reason for the decrease in the synthesis and accumulation of triterpenoids.