Linalool Inactivates TORC1, Disrupting Ribosome Biogenesis and Inhibiting <i>Fusarium oxysporum</i> Growth

Fusarium oxysporum (Fo), a pathogenic fungus threatening medicinal plants like Panax notoginseng, causes severe root rot. Linalool, the primary component of Alpinia officinarum Hance essential oil (EO), is a biologically active compound with demonstrated anti-inflammatory, antibacterial, and antioxidant properties. Notably, it has garnered considerable attention for its remarkable antifungal efficacy. In vitro studies revealed that linalool significantly inhibited Fo hyphal growth. At 12.08 mmol/L, spore germination decreased by 43%, whereas spore yield dropped by 99%. Transcriptomic analysis identified 562 upregulated and 4095 downregulated genes in the linalool-treated group. The upregulated genes were predominantly enriched in pathways related to metabolism, oxidative phosphorylation, and carbohydrate metabolism, indicating adaptive stress responses. Downregulated genes were primarily associated with the ribosome biogenesis, transcription, and spliceosome pathways, with ribosome biogenesis showing the most pronounced inhibition. Linalool treatment inactivated TORC1 (target of rapamycin complex 1), a crucial regulator of ribosomal biogenesis and protein synthesis. This disruption led to reduced expression of ribosome-related genes, severely impairing protein synthesis and fungal growth. The study highlights linalool's strong antifungal activity, primarily by targeting ribosome biogenesis. Future research should investigate its effects and safety in field applications, offering potential strategies for managing diseases in medicinal plants such as P. notoginseng.