Gene expression profiling to elucidate the promotive effects of the volatile organic compound 3-octanone on the mycelial growth of Ganoderma lucidum

To investigate the effects of fungal volatile organic compounds (FVOCs) on the mycelial growth of Ganoderma lucidum, and to elucidate the molecular mechanisms underlying the growth-promoting effect of 3-octanone. G. lucidum was cultivated with 1-octen-3-ol, 3-octanol and 3-octanone for 7 days, after which colony diameter and mycelial dry weight were measured to assess their effects on mycelial growth. RNA-seq was used to investigate gene expression changes following 3-octanone exposure. While 1-octen-3-ol or 3-octanol inhibited mycelial growth in G. lucidum, 3-octanone promoted it. In total, 590 differentially expressed genes (DEGs), including 162 upregulated and 428 downregulated genes, were identified following 3-octanone exposure. Functional annotation revealed that among the DEGs, 23 genes were related to fungal cell wall biosynthesis and remodeling, whereas 21 genes were involved in plant-derived polysaccharide degradation. Furthermore, significant expression changes were observed in genes related to secondary metabolism. Our results indicate that G. lucidum can use 3-octanone as a signal to recognize other fungi, potentially facilitating the expansion of its own territory within wood in nature.