PDF(Pubmed)
Abstract：
Fire blight, caused by the Gram-negative bacterium Erwinia amylovora, poses a substantial threat to pome fruit production worldwide. Despite existing control strategies, a pressing need remains for sustainable and environmentally friendly fire blight management. Myxobacteria, renowned for their predatory behavior and potent enzymes, emerge as a groundbreaking biocontrol approach with significant potential. Here, we report the biocontrol potential of a novel Myxococcus fulvus WCH05, against E. amylovora. Using various in vitro and planta assays, we demonstrated the multifaceted biocontrol abilities of strain WCH05. In plate predation assays, strain WCH05 exhibited not only strong predation against E. amylovora but also broad-spectrum activities against other plant pathogenic bacteria. Pre-treatment with strain WCH05 significantly decreased pear blossom blight incidence in detached inflorescence assays, achieving a controlled efficacy of 76.02% that rivaled the antibiotic streptomycin (79.79%). In greenhouse trials, strain WCH05 effectively reduced the wilting rate and disease index in young pear seedlings, exhibiting both protective (73.68%) and curative (68.66%) control. Further investigation revealed that the biocontrol activity of strain WCH05 relies on both direct contact and extracellular enzyme secretion. While cell extracts lacked inhibitory activity, ammonium sulfate-precipitated secreted proteins displayed potent lytic activity against E. amylovora. Substrate spectrum analysis identified peptidases, lipases, and glycosidases among the secreted enzymes, suggesting their potential roles in pathogen degradation and biocontrol efficacy. This study presents the first evidence of Myxococcus fulvus WCH05 as a biocontrol agent against fire blight. Its potent predatory abilities and enzymatic arsenal highlight its potential for sustainable disease management in pome fruit production. Future research will focus on identifying and characterizing specific lytic enzymes and optimizing strain WCH05 application strategies for field efficacy.
摘要：
火疫病,由革兰氏阴性细菌淀粉样欧文氏菌引起，对全球pome水果生产构成重大威胁。尽管现有的控制策略，迫切需要可持续和环保的火灾疫病管理。粘细菌,以其掠夺性行为和强效酶而闻名，成为具有巨大潜力的开创性生物防治方法。这里,我们报道了一种新型的黄状粘球菌WCH05对淀粉样大肠杆菌的生物防治潜力。使用各种体外和植物测定，我们证明了菌株WCH05的多方面生物防治能力。在平板捕食试验中，菌株WCH05不仅表现出强烈的捕食作用，而且还表现出对其他植物病原菌的广谱活性。在分离的花序测定中，用菌株WCH05预处理可显着降低梨花枯萎病的发生率，与抗生素链霉素（79.79％）相比，控制疗效为76.02％。在温室试验中，菌株WCH05有效降低了梨幼苗的枯萎率和病情指数，同时表现出保护性(73.68%)和治愈性(68.66%)对照。进一步的研究表明，菌株WCH05的生物防治活性依赖于直接接触和胞外酶分泌。虽然细胞提取物缺乏抑制活性，硫酸铵沉淀的分泌蛋白对淀粉芽孢杆菌显示出有效的裂解活性。底物谱分析鉴定了肽酶，脂肪酶，和分泌的酶中的糖苷酶，表明它们在病原体降解和生物防治功效中的潜在作用。这项研究提供了富型粘球菌WCH05作为抗火疫病的生物防治剂的第一个证据。其强大的捕食能力和酶的武器库突出了其在pome水果生产中可持续疾病管理的潜力。未来的研究将集中在鉴定和表征特定的裂解酶，并优化菌株WCH05的田间功效应用策略。
