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The antifungal activity and mechanism of action of limonene against tobacco-isolated Fusarium oxysporum causing tobacco root rot
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DOI:10.3389/fpls.2026.1897693.png)
Abstract
En 中文
Tobacco root rot (TRR); caused by Fusarium oxysporum; poses a significant threat to tobacco production. Synthetic fungicides widely used to control this soil-borne pathogen frequently cause fungicide resistance and environmental contamination. Limonene; a natural terpene with potent antifungal activity; features low residue and high biosafety; rendering it a promising natural substitute for chemical fungicides against TRR. This study aimed to investigate the antifungal activity and mechanisms of limonene against F. oxysporum using in vitro assays; physiological tests; transcriptomics; and metabolomics. The results demonstrated that limonene significantly inhibited mycelial growth and spore proliferation; with an EC50 of 201.2 μg/mL (1.48 mM). It exhibited a dose-dependent repellent effect on the chemotactic behavior of F. oxysporum; with effective concentrations as low as 25 μg/mL (0.18 mM). Furthermore; it disrupted cell membrane integrity and permeability at concentrations as low as 100 μg/mL (0.73 mM). Transcriptomic screening identified 3; 871 differentially expressed genes (DEGs); which were significantly enriched in ribosome; proteasome; ER protein processing; autophagy and glyoxylate metabolism pathways. Eight representative key DEGs (cat1; rhogap; tf; cyc; bro1; mic12; rpl13; clptm1l) related to fungal growth and stress response were verified by RT-qPCR verification; and their expression trends were consistent with the transcriptomic results. Metabolomic analysis revealed 626 differential accumulated metabolites (DAMs); three key metabolites (ortho-Hydroxyphenylacetic acid; 4-Methylphenol and Lenticin) were significantly altered under limonene treatment. These DAMs were mainly enriched in starch and sucrose; riboflavin; folate and tyrosine metabolism pathways. Multi-omics joint analysis indicated that key targeted pathways including energy metabolism; amino acid metabolism; lipid metabolism; and protein synthesis and degradation were regulated. In conclusion; limonene inhibits F. oxysporum through multiple mechanisms; including cell membrane damage; chemotaxis blockage; transcriptional regulation; and metabolic disturbance. This study provides scientific support for the development of limonene as a green botanical fungicide for controlling tobacco root rot.
Keywords:
multi-omics
Fusarium oxysporum
antifungal mechanism
limonene
tobacco root rot
Journal
IF:
4.8
Papers:
3.4W
Citations:
14.7W
