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

<i>Panax notoginseng</i>, a high-value medicinal crop, suffers substantial yield losses due to <i>Fusarium oxysporum</i>-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 <i>F. oxysporum</i> 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 <i>Saccharomyces cerevisiae</i>, <i>Homo sapiens</i>, and <i>Arabidopsis thaliana</i>. Structural analyses revealed distinct motif compositions and domain architectures among FoHAT members, while promoter <i>cis</i>-element profiling suggested potential subfunctionalization via stress-responsive regulatory mechanisms. Functional investigations demonstrated that major notoginsenosides present in <i>P. notoginseng</i> 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 <i>Fo-Hat1_N</i> 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.