2-苯基丙烯酸对梨火疫病原菌毒力因子的抑制作用

Inhibitory effects of 2-phenylacrylic acid on the virulence factors of Erwinia amylovora

摘要:

背景 梨火疫病由解淀粉欧文氏菌(Erwinia amylovora)引起，是一种对全球蔷薇科(Rosaceae)果树产业具有毁灭性的细菌性病害。目的 探究在亚抑菌浓度下，2-苯基丙烯酸对梨火疫病原菌的群体感应抑制效果，为开发新型防治药剂奠定基础。方法 测定2-苯基丙烯酸对菌株Ea-213的最小抑菌浓度(minimum inhibitory concentration, MIC)，并在亚抑菌浓度下，通过结晶紫染色法、蒽酮-硫酸法等，评估其对生物膜形成、胞外多糖产生、运动性以及多种细胞壁降解酶活性的影响。结果 菌株Ea-213的MIC确定为1 mg/mL，菌株CV026的MIC为0.5 mg/mL。2-苯基丙烯酸在亚抑菌浓度下不影响菌株Ea-213生长，但对革兰氏阴性菌株CV026具有明显的群体感应效果。在1/2 MIC浓度下，2-苯基丙烯酸对菌株Ea-213的生物膜形成、胞外多糖产生及运动性均具有显著的抑制效果。同时，对菌株Ea-213分泌的纤维素酶、木聚糖酶、果胶裂解酶和多聚半乳糖醛酸酶活性均有显著抑制作用，其中对多聚半乳糖醛酸酶的抑制率最高，在1/2 MIC浓度下可达53.8%。结论 2-苯基丙烯酸可通过干扰群体感应系统，有效减弱梨火疫病原菌的多种关键毒力，展现出作为新型梨火疫病生物防治剂的巨大潜力。

Abstract:

Background Fire blight, caused by Erwinia amylovora, is a devastating bacterial disease affecting the global fruit plant industry of Rosaceae.Objective Explored the inhibitory effect of 2-phenylacrylic acid at subinhibitory concentrations against the quorum sensing of E. amylovora, aiming to underpin the development of novel control agents.Methods The minimum inhibitory concentration (MIC) of 2-phenylacrylic acid against strain Ea-213 was determined. The effects of 2-phenylacrylic acid at subinhibitory concentrations on the biofilm formation, extracellular polysaccharide production, motility, and activities of various cell wall-degrading enzymes were evaluated via crystal violet staining and the anthrone-sulfuric acid assayResults The MIC of 2-phenylacrylic acid was determined to be 1 mg/mL against strain Ea-213 and 0.5 mg/mL against the Gram-negative biosensor strain CV026. At subinhibitory concentrations, 2-phenylacrylic acid did not affect the growth of strain Ea-213 but exhibited pronounced quorum-quenching activity against CV026. At 1/2 MIC, 2-phenylacrylic acid significantly inhibited the biofilm formation, extracellular polysaccharide production, and motility of strain Ea-213. Furthermore, the compound markedly suppressed the activities of cellulase, xylanase, pectin lyase, and polygalacturonase secreted by E. amylovora. Particularly, 2-phenylacrylic acid exerted the most significant inhibitory effect on polygalacturonase, with an inhibition rate reaching 53.8% at 1/2 MIC.Conclusion 2-Phenylacrylic acid can effectively attenuate multiple key virulence factors of E. amylovora by interfering with its quorum sensing system, demonstrating considerable potential as a novel biocontrol agent against fire blight.