D-limonene inhibits the growth of Fusarium proliferatum by decreasing H3K9ac and H3K27ac modifications.

BACKGROUND: Fusarium proliferatum, a major pathogen causing root rot in Panax notoginseng, severely threatens sustainable cultivation. While chemical pesticides face resistance and environmental risks, plant-derived alternatives are urgently needed. D-limonene, a natural monoterpene with broad antimicrobial activity, remains unexplored against F. proliferatum. RESULTS: D-limonene strongly inhibited F. proliferatum growth: 200 mM suppressed hyphal growth by 73.89%, reduced sporulation by 73.6%, and impaired conidia germination. It disrupted membrane integrity, increasing extracellular conductivity by 64.3% within 4 h. Transcriptomics revealed 1,134 upregulated and 1,240 downregulated genes, with downregulated genes enriched in ribosomal translation and endoplasmic reticulum protein processing. Critically, D-limonene reduced histone acetylation (H3K9ac/H3K27ac). ChIP-seq confirmed that H3K9 hypoacetylation inhibited ribosomal genes (RPS9, RPS3, RPS4), while H3K27 hypoacetylation suppressed lipid metabolism and mitochondrial biogenesis, collectively stalling fungal growth. CONCLUSIONS: D-limonene combats F. proliferatum by damaging cell membranes and reprogramming histone acetylation to disrupt ribosome function and mitochondrial biosynthesis. This dual-action mechanism highlights its potential as an eco-friendly botanical fungicide against root rot.