Molecular mechanism of butylidenephthalide against <scp> <i>Sclerotium rolfsii</i> </scp> with affecting energy metabolism

BACKGROUND: Given the resistance of plant pathogenic fungi to traditional chemical fungicides and the associated risks to human and environmental safety, there is an urgent need for safe and effective alternative fungicides. Butylidenephthalide, an active compound from Ligusticum chuanxiong essential oil, exhibits potent antifungal activity against Sclerotium rolfsii, a destructive plant pathogen that causes stem rot in peanuts. However, the molecular mechanism of butylidenephthalide against S. rolfsii remains unclear. RESULTS: . Additionally, butylidenephthalide induced an increase in hydrogen peroxide (H₂O₂) levels, indicating the induction of oxidative stress in S. rolfsii. Transcriptomic results indicated that a total of 1477 differentially expressed genes (DEGs) were detected in the mycelia of S. rolfsii treated with butylidenephthalide for 12 h, including 521 up- and 956 downregulated genes. Transcriptomic and metabolomic analyses revealed that butylidenephthalide treatment resulted in the enrichment of DEGs primarily in pathways related to energy metabolism, cell membrane metabolism, the antioxidant system, ATP-binding cassette (ABC) transporters and mitogen-activated protein kinases (MAPK) signaling. Additionally, butylidenephthalide interfered with the tricarboxylic acid (TCA) cycle and oxidative phosphorylation pathways, which are associated with mitochondrial function. CONCLUSION: Our results demonstrated the molecular mechanism of natural phthalide compound butylidenephthalide and application potential as an alternative agent to control S. rolfsii. © 2026 Society of Chemical Industry.