摘要
【背景】梨火疫病是由解淀粉欧文氏菌(Erwiniaamylovora)引起的重大植物病害,其毒力因子由该菌群体感应系统调控。群体感应抑制剂(quorum sensing inhibitor,QSI)作为一种新型活性物,可以通过阻断病原细菌的群体感应通路,进而降低毒力因子代谢,是防治梨火疫病的潜在新策略。【目的】挖掘梨火疫病欧文氏菌群体感应抑制剂,为梨火疫病防控提供理论依据。【方法】通过对菌株D67发酵并制备发酵粗提物,进而开展其对紫色色小杆菌(Chromobacteriumviolaceum)CV026和梨火疫病原菌的抑菌活性测试,分析不同亚抑菌浓度粗提物溶液对欧文氏菌生物膜、胞外多糖、运动性和胞外酶代谢的影响。【结果】菌株D67发酵粗提物具有明显的群体感应抑制活性和抑菌活性,其对梨火疫病欧文氏菌最小抑菌浓度为2mg/mL;在亚抑菌浓度下,可有效降低梨火疫病原菌的运动能力,并且对菌株生物膜、胞外多糖和多种胞外酶代谢具有显著影响,并呈明显的浓度依赖性。在0.25mg/mL浓度下,梨火疫病原菌生物膜抑制率为60.1%,与阳性对照丁香酚处理效果相当;在1/2MIC浓度下,多聚半乳糖醛酸酶和果胶裂解酶的抑制率高达76.45%和34.80%,并在离体叶片实验中展现较好的防治效果。【结论】菌株D67发酵代谢产物具有明显的群体感应抑制活性,能显著抑制欧文氏菌毒力因子的产生,为梨火疫病生物防治提供了新思路。
[Background]Pear fire blight,caused by Erwinia amylovora,is a devastating plant disease.The virulence factors of this pathogen are regulated by the quorum sensing(QS)system.Quorum sensing inhibitors(QSIs),as novel bioactive compounds,can reduce the metabolism of virulence factors by disrupting the QS pathways of pathogenic bacteria,representing a potential new strategy for controlling pear fire blight.[Objective]To explore a QSI against E.amylovora and provide a theoretical foundation for the prevention and control of pear fire blight.[Methods]The crude extract of strain D67 was prepared through fermentation and tested for the inhibitory activities against Chromobacterium violaceum CV026 and E.amylovora.The effects of sub-inhibitory concentrations of the crude extract on the biofilm formation,extracellular polysaccharide production,motility,and extracellular enzyme metabolism of E.amylovora were analyzed.[Results]The crude fermentation extract of strain D67 exhibited significant QS inhibitory activity and antibacterial activity.The minimum inhibitory concentration(MIC)of the crude extract against E.amylovora was 2 mg/mL.At sub-inhibitory concentrations,the crude extract reduced the motility and significantly impacted the biofilm formation,extracellular polysaccharide production,and extracellular enzyme metabolism of E.amylovora in a concentration-dependent manner.The extract at 0.25 mg/mL showed the inhibition rate of 60.1%on biofilm formation,which was comparable to that of the positive control eugenol.The extract at 1/2 MIC showed the inhibition rates of 76.45%and 34.80%for polygalacturonase and pectin lylase,respectively.Additionally,the crude extract demonstrated effective control in an in vitro leaf assay.[Conclusion]The fermentation metabolites of strain D67 exhibited significant QS inhibitory activity and significantly inhibited the production of virulence factors of E.amylovora,providing a novel approach for the biocontrol of pear fire blight.
作者
江星彤
柏晓玉
冯玉莲
李雪
李梅
朱艳蕾
张志东
JIANG Xingtong;BAI Xiaoyu;FENG Yulian;LI Xue;LI Mei;ZHU Yanlei;ZHANG Zhidong(College of Life Sciences,Xinjiang Normal University,Urumqi 830054,Xinjiang,China;Xinjiang Laboratory of Special Environmental Microbiology,Institute of Applied Microbiology,Xinjiang Academy of Agricultural Sciences,Urumqi 830091,Xinjiang,China;College of Life Science and Technology,Xinjiang University,Urumqi 830000,Xinjiang,China;College of Food Sciences and Pharmacy,Xinjiang Agricultural University,Urumqi 830052,Xinjiang,China)
出处
《微生物学通报》
北大核心
2025年第7期3165-3175,共11页
Microbiology China
基金
新疆维吾尔自治区“天山英才”项目(2022TSYCCX0067)
国家自然科学基金(32060004)。
关键词
群体感应抑制剂
欧文氏菌
毒力因子
quorum sensing inhibitor
Erwinia amylovora
virulence factors
