BACKGROUND Myxobacteria are micropredators in the soil ecosystem with the capacity to move and feed cooperatively. Some myxobacterial strains have been used to control soil-borne fungal phytopathogens. However, interactions among myxobacteria, plant pathogens, and the soil microbiome are largely unexplored. In this study, we aimed to investigate the behaviors of the myxobacterium Corallococcus sp. strain EGB in the soil and its effect on the soil microbiome after inoculation for controlling cucumber Fusarium wilt caused by Fusarium oxysporum f. sp. cucumerinum (FOC). RESULTS A greenhouse and a 2-year field experiment demonstrated that the solid-state fermented strain EGB significantly reduced the cucumber Fusarium wilt by 79.6% (greenhouse), 66.0% (2015, field), and 53.9% (2016, field). Strain EGB adapted to the soil environment well and decreased the abundance of soil-borne FOC efficiently. Spatiotemporal analysis of the soil microbial community showed that strain EGB migrated towards the roots and root exudates of the cucumber plants via chemotaxis. Cooccurrence network analysis of the soil microbiome indicated a decreased modularity and community number but an increased connection number per node after the application of strain EGB. Several predatory bacteria, such as Lysobacter, Microvirga, and Cupriavidus, appearing as hubs or indicators, showed intensive connections with other bacteria. CONCLUSION The predatory myxobacterium Corallococcus sp. strain EGB controlled cucumber Fusarium wilt by migrating to the plant root and regulating the soil microbial community. This strain has the potential to be developed as a novel biological control agent of soil-borne Fusarium wilt. Video abstract.

中文翻译：

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掠食性粘杆菌通过调节土壤微生物群落来控制黄瓜枯萎病。

背景技术粘细菌是土壤生态系统中的微捕食者，具有协同移动和觅食的能力。一些粘细菌菌株已用于控制土壤传播的真菌植物病原体。然而，粘细菌，植物病原体和土壤微生物组之间的相互作用在很大程度上尚待探索。在这项研究中，我们旨在调查粘杆菌Corallococcus sp的行为。接种黄瓜枯萎病引起黄瓜枯萎病接种后土壤上的EGB菌株及其对土壤微生物组的影响。sp。黄瓜（FOC）。结果温室和两年的田间试验表明，固态发酵菌株EGB显着降低了黄瓜枯萎病79.6％（温室），66.0％（2015年，田间）和53.9％（2016年，田间）。EGB菌株很好地适应了土壤环境，有效降低了土壤中FOC的含量。对土壤微生物群落的时空分析表明，EGB菌株通过趋化作用向黄瓜植物的根和根分泌物迁移。对土壤微生物组的共现网络分析表明，应用菌株EGB后，模块性和群落数目减少，但每个节点的连接数目增加。几种掠食性细菌，如溶血细菌，Microvirga和Cupriavidus，表现为集线器或指示剂，显示与其他细菌的紧密连接。结论掠食性粘杆菌Corallococcus sp。EGB菌株通过迁移到植物根部并调节土壤微生物群落来控制黄瓜枯萎病。该菌株有潜力被开发为土壤传播的镰刀菌枯萎病的新型生物防治剂。录像摘要。