Genome-Wide Identification of Histone Acetyltransferases in Fusarium oxysporum and Their Response to Panax notoginseng Notoginsenosides

Panax notoginseng, a high-value medicinal crop, suffers substantial yield losses due to Fusarium oxysporum-mediated root rot, for which no molecularly defined control targets are currently available. Histone acetyltransferases (HATs) serve as crucial epigenetic regulators of fungal development and stress responses; however, their functional roles in F. oxysporum remain largely unexplored. In this study, we systematically identified six FoHAT genes via genome-wide analysis and classified them into evolutionarily conserved subfamilies through phylogenetic comparison with orthologs from Saccharomyces cerevisiae, Homo sapiens, and Arabidopsis thaliana. Structural analyses revealed distinct motif compositions and domain architectures among FoHAT members, while promoter cis-element profiling suggested potential subfunctionalization via stress-responsive regulatory mechanisms. Functional investigations demonstrated that major notoginsenosides present in P. notoginseng root exudates—R1, Rg1, Rg2, Re, and Rd—dynamically influenced both spore germination and FoHAT expression profiles. Intriguingly, each notoginsenoside exerted concentration-dependent non-linear effects on spore germination, either inhibiting or promoting the process. Concurrently, notoginsenoside exposure triggered compensatory transcriptional responses, most notably a rebound in Fo-Hat1_N expression from 9% to 112% under Rd treatment. This work establishes an initial epigenetic framework for combating Fusarium root rot in medicinal plants and offers a foundation for developing HAT-targeted small-molecule inhibitors.