A New Insight into 6-Pentyl-2H-pyran-2-one against via TOR Pathway.

The litchi downy blight disease of litchi caused by accounts for severe losses in the field and during storage. While ample quantitative studies have shown that 6-pentyl-2H-pyran-2-one (6PP) possesses antifungal activities against multiple plant pathogenic fungi, the regulatory mechanisms of 6PP-mediated inhibition of fungal pathogenesis and growth are still unknown. Here, we investigated the potential molecular targets of 6PP in the phytopathogenic oomycetes through integrated deployment of RNA-sequencing, functional genetics, and biochemical techniques to investigate the regulatory effects of 6PP against . Previously we demonstrated that 6PP exerted significant oomyticidal activities. Also, comparative transcriptomic evaluation of strains treated with 6PP Revealed significant up-regulations in the expression profile of TOR pathway-related genes, including and the transcription factors . We also noticed that 6PP treatment down-regulated putative negative regulatory genes of the TOR pathway, including and in . Protein-ligand binding analyses revealed stable affinities between PlYY1, PlCytochrome C, PlSpm1, PlrhoH12 proteins, and the 6PP ligand. Phenotypic characterization of targeted gene deletion strains generated in this study using CRISPR/Cas9 and homologous recombination strategies significantly reduced the vegetative growth, sporangium, encystment, zoospore release, and pathogenicity of . These findings suggest that 6PP-mediated activation of expression positively regulates TOR-related responses and significantly influences vegetative growth and the virulence of . The current investigations revealed novel targets for 6PP and underscored the potential of deploying 6PP in developing management strategies for controlling the litchi downy blight pathogen.