Pan Deng, Wang Xing-Yun, Zhou Jin-Wei, Yang Liang, Khan Abbas, Wei Dong-Qing, Li Jun-Jian, Jia Ai-Qun
School of Pharmaceutical Sciences, Hainan University, Haikou, China.
State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, China.
J Appl Microbiol. 2022 Nov;133(5):3161-3175. doi: 10.1111/jam.15774. Epub 2022 Aug 22.
In the current study the anti-virulence and anti-biofilm activities of the cinnamic acid derivative, 3-methoxycinnamic acid, was investigated against Agrobacterium tumefaciens.
Based on the disc diffusion test and β-galactosidase activity assay, 3-methoxycinnamic acid was shown to interfere with the quorum sensing (QS) system of A. tumefaciens. Crystal violet staining assay, phenol-sulfuric acid method, Bradford protein assay and confocal laser scanning microscopy (CLSM) revealed that the biofilm formation of A. tumefaciens was inhibited after the treatment of 3-methoxycinnamic acid. Employing high-performance liquid chromatography (HPLC) analysis of culture supernatant revealed that the production of 3-oxo-octanoylhomoserine lactone (3-oxo-C8-HSL) decreased concentration-dependently after treatment with 3-methoxycinnamic acid. Swimming and chemotaxis assays also indicated that 3-methoxycinnamic acid had a good effect on reducing the motility and chemotaxis of A. tumefaciens. In addition, the RT-qPCR, molecular docking and simulations further demonstrated that 3-methoxycinnamic acid could competitively inhibit the binding of 3-oxo-C8-HSL to TraR and down-regulate virulence-related genes.
3-Methoxycinnamic acid is proved to have good anti-virulence and anti-biofilm activities against A. tumefaciens.
This is the first study that investigates the anti-virulence and anti-biofilm activities of 3-methoxycinnamic acid against A. tumefaciens. With its potential QS-related virulence and biofilm inhibitory activities, 3-methoxycinnamic acid is expected to be developed as a potent pesticide or adjuvant for the prevention and treatment of crown gall caused by A. tumefaciens.
在本研究中，研究了肉桂酸衍生物3-甲氧基肉桂酸对根癌土壤杆菌的抗毒力和抗生物膜活性。
基于纸片扩散试验和β-半乳糖苷酶活性测定，结果表明3-甲氧基肉桂酸会干扰根癌土壤杆菌的群体感应（QS）系统。结晶紫染色试验、苯酚-硫酸法、Bradford蛋白测定法和共聚焦激光扫描显微镜（CLSM）显示，用3-甲氧基肉桂酸处理后，根癌土壤杆菌的生物膜形成受到抑制。通过高效液相色谱（HPLC）分析培养上清液发现，用3-甲氧基肉桂酸处理后，3-氧代辛酰高丝氨酸内酯（3-氧代-C8-HSL）的产生呈浓度依赖性降低。游动和趋化试验还表明，3-甲氧基肉桂酸对降低根癌土壤杆菌的运动性和趋化性有良好效果。此外，RT-qPCR、分子对接和模拟进一步证明，3-甲氧基肉桂酸可竞争性抑制3-氧代-C8-HSL与TraR的结合，并下调毒力相关基因。
证明3-甲氧基肉桂酸对根癌土壤杆菌具有良好的抗毒力和抗生物膜活性。
这是第一项研究3-甲氧基肉桂酸对根癌土壤杆菌的抗毒力和抗生物膜活性的研究。鉴于其潜在的与群体感应相关的毒力和生物膜抑制活性，预计3-甲氧基肉桂酸可开发成为一种有效的农药或佐剂，用于预防和治疗由根癌土壤杆菌引起的冠瘿病。
