Antifungal activity and inhibitory mechanism of essential oil from fresh and fallen leaves of Cinnamomum camphora (L.) presl against zearalenone-producing Fusarium graminearum

Fusarium graminearum is a major pathogen affecting wheat and corn, leading to yield losses and health risks from mycotoxin contamination. Essential oils from Cinnamomum camphora (L.) Presl have emerged as promising natural food preservatives. This study systematically investigates the inhibitory effects and molecular mechanisms of fresh leaf essential oil (FLEO) and fallen leaf essential oil (FALEO) against Fusarium graminearum . The chemical compositions of both essential oils were analyzed using GC-MS, and their inhibitory concentrations on mycelial growth and zearalenone (ZEN) biosynthesis were determined through in vitro assays. The essential oils disrupt cell membrane integrity and induce oxidative stress, elucidating their antifungal mechanisms through transcriptomic analysis. Results showed that FLEO at 12.8 μL/mL and FALEO at 3.2 μL/mL completely inhibited mycelial growth and ZEN production. Mechanistic studies indicated that the essential oils increased membrane permeability and significantly down-regulated key genes related to ergosterol synthesis, ZEN biosynthesis, and oxidative stress pathways in Fusarium graminearum . This study clarifies the antifungal mechanisms of FLEO and FALEO, highlighting FALEO's superior inhibitory effect. Due to its efficient antifungal activity, sustainability, and eco-friendliness, FALEO shows significant potential for agricultural disease prevention and food preservation, laying a crucial foundation for its development as an environmentally friendly fungicide. • Cinnamomum camphora leaf essential oil can significantly inhibit Fusarium graminearum growth and zearalenone production. • FALEO exhibits superior antifungal efficacy compared to FLEO. • Transcriptomics have revealed downregulation of ergosterol and toxin biosynthesis genes. • FALEO shows potential as a sustainable antifungal agent due to its efficiency and eco-friendliness.