Antimicrobial Activity of Natural Plant Compound Carvacrol Against Soft Rot Disease Agent Dickeya zeae

• Published in: Current microbiology Vol. 78; no. 9; pp. 3453 - 3463
• Main Authors: Jiang, Shangbo, Zhang, Jingxin, Yang, Qiyun, Sun, Dayuan, Pu, Xiaoming, Shen, Huifang, Li, Qiqin, Wang, Zhongwen, Lin, Birun
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.09.2021; Springer Nature B.V
• Subjects: Antiinfectives and antibacterials; Antimicrobial activity; Antimicrobial agents; Bananas; Biofilms; Biomedical and Life Sciences; Biotechnology; Carvacrol; Cell membranes; Crop diseases; Dickeya zeae; Essential oils; Hydrophobicity; Inoculation; Life Sciences; Medical treatment; Membrane potential; Microbiology; Micrography; Minimum inhibitory concentration; Nucleic acids; Pathogenicity; Pathogens; Photomicrographs; Plant diseases; Scanning electron microscopy; Seedlings; Signs and symptoms; Soft rot; Swimming; Virulence; Virulence factors
• ISSN: 0343-8651; 1432-0991
• DOI: 10.1007/s00284-021-02609-3

Dickeya zeae is a globally important bacterial pathogen that has been reported to cause severe soft rot diseases in several essential food crops, including bananas, rice, maize, and potatoes. Carvacrol, a hydrophobic terpene component, is found in aromatic plants of the Labiatae family and various essential oils. However, little work has been done on its antimicrobial potential against D. zeae . This study aimed to evaluate the antimicrobial activity and the functional mechanism of carvacrol against D. zeae . The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of carvacrol against D. zeae were 0.1 mg/mL and 0.2 mg/mL, respectively. Carvacrol affected the cell membrane of D. zeae , as revealed by decreased intracellular ATP concentration, nucleic acid leakage, and decreased membrane potential. Scanning electron microscopy (SEM) micrographs confirmed that D. zeae cell membranes were damaged by carvacrol. Furthermore, a significant inhibition of D. zeae swimming motility and biofilm formation was observed following treatments with carvacrol at sub-inhibitory concentrations, indicating a significantly negative effect on these virulence factors. Accordingly, the tissue infection test revealed that carvacrol significantly reduced the pathogenicity of D . zeae . In a pot experiment, inoculated banana seedlings displayed remarkably lesser disease symptoms following treatment with carvacrol, and the control efficiency for banana soft rot was 32.0% at 14 days post-inoculation. To summarize, carvacrol exhibits strong antimicrobial activity against D . zeae and great potential applications in the control of D . zeae -associated crop diseases.