A predatory myxobacterium controls cucumber Fusarium wilt by regulating the soil microbial community

Abstract

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.

OsPAL2-1 Mediates Allelopathic Interactions Between Rice and Specific Microorganisms in the Rhizosphere Ecosystem

“…In cucumber, the myxobacterium Corallococcus sp. was found migrating toward the roots and root exudates of the cucumber plants via chemotaxis (Ye et al, 2020). In this study, the phenolic acid mixture secreted from the allelopathic rice could promote the production of secondary metabolites of the myxobacteria ( Supplementary Table S1), of which quercetin was determined as the main allelochemical, suggesting that it might interact with other toxic ketones and quinones to influence the herbicidal potential of the myxobacteria (Table 4).…”

“…Previous studies reported that myxococcales are known as metabolic factories and can produce a large number of secondary metabolites and can inhibit the germination of weeds and the proliferation of various harmful bacteria and fungi (Weissman and Müller, 2009). Ye et al (2020) also documented that myxobacterium Corallococcus sp. strain EGB modified the FIGURE 6 | The effects of exogenously added quercetin on the growth of barnyard grass.…”

Organic Fertilization Assembles Fungal Communities of Wheat Rhizosphere Soil and Suppresses the Population Growth of Heterodera avenae in the Field

“…To construct the co-occurrence network of fungal genera in each treatment, only the abundant genera were used (the 50 most abundant). Because the data did not conform to the assumptions of the general linear model, significant correlations between any two genera were calculated using Networkx software ( ), with Spearman’s | r| > 0.7 and a p -value < 0.05 following the previously described method ( Ye et al, 2020 ). Networks visualization was calculated with the interactive platform Gephi ( ).…”

Rhizosphere immunity: targeting the underground for sustainable plant health management

“…can affect interactions with other microorganisms [66][67][68] while soil acidification caused by Rhizoctonia solani triggers changes in microbiome composition and activity [69] . The presence of the pathogen can also promote the reproduction of natural enemies such as viruses [70] , predatory bacteria [71] , and protists [72] , potentially triggering cascades in microbial trophic networks, which could feed back in the activation of plant immune responses.…”