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Tsumori C, Matsuo S, Murai Y, Kai K. Quorum Sensing-Dependent Invasion of Ralstonia solanacearum into Fusarium oxysporum Chlamydospores. Microbiol Spectr 2023; 11:e0003623. [PMID: 37367297 PMCID: PMC10433826 DOI: 10.1128/spectrum.00036-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 06/02/2023] [Indexed: 06/28/2023] Open
Abstract
Strains of the Ralstonia solanacearum species complex (RSSC), although known as the causative agent of bacterial wilt disease in plants, induce the chlamydospores of many fungal species and invade them through the spores. The lipopeptide ralstonins are the chlamydospore inducers produced by RSSC and are essential for this invasion. However, no mechanistic investigation of this interaction has been conducted. In this study, we report that quorum sensing (QS), which is a bacterial cell-cell communication, is important for RSSC to invade the fungus Fusarium oxysporum (Fo). ΔphcB, a deletion mutant of QS signal synthase, lost the ability to both produce ralstonins and invade Fo chlamydospores. The QS signal methyl 3-hydroxymyristate rescued these disabilities. In contrast, exogenous ralstonin A, while inducing Fo chlamydospores, failed to rescue the invasive ability. Gene-deletion and -complementation experiments revealed that the QS-dependent production of extracellular polysaccharide I (EPS I) is essential for this invasion. The RSSC cells adhered to Fo hyphae and formed biofilms there before inducing chlamydospores. This biofilm formation was not observed in the EPS I- or ralstonin-deficient mutant. Microscopic analysis showed that RSSC infection resulted in the death of Fo chlamydospores. Altogether, we report that the RSSC QS system is important for this lethal endoparasitism. Among the factors regulated by the QS system, ralstonins, EPS I, and biofilm are important parasitic factors. IMPORTANCE Ralstonia solanacearum species complex (RSSC) strains infect both plants and fungi. The phc quorum-sensing (QS) system of RSSC is important for parasitism on plants, because it allows them to invade and proliferate within the hosts by causing appropriate activation of the system at each infection step. In this study, we confirm that ralstonin A is important not only for Fusarium oxysporum (Fo) chlamydospore induction but also for RSSC biofilm formation on Fo hyphae. Extracellular polysaccharide I (EPS I) is also essential for biofilm formation, while the phc QS system controls these factors in terms of production. The present results advocate a new QS-dependent mechanism for the process by which a bacterium invades a fungus.
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Affiliation(s)
- Chiaki Tsumori
- Graduate School of Agriculture, Osaka Metropolitan University, Osaka, Japan
| | - Shoma Matsuo
- Graduate School of Agriculture, Osaka Metropolitan University, Osaka, Japan
| | - Yuta Murai
- Graduate School of Agriculture, Osaka Metropolitan University, Osaka, Japan
| | - Kenji Kai
- Graduate School of Agriculture, Osaka Metropolitan University, Osaka, Japan
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Sadiq FA, Hansen MF, Burmølle M, Heyndrickx M, Flint S, Lu W, Chen W, Zhang H. Towards understanding mechanisms and functional consequences of bacterial interactions with members of various kingdoms in complex biofilms that abound in nature. FEMS Microbiol Rev 2022; 46:6595875. [PMID: 35640890 DOI: 10.1093/femsre/fuac024] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 04/11/2022] [Accepted: 05/27/2022] [Indexed: 11/12/2022] Open
Abstract
The microbial world represents a phenomenal diversity of microorganisms from different kingdoms of life which occupy an impressive set of ecological niches. Most, if not all, microorganisms once colonise a surface develop architecturally complex surface-adhered communities which we refer to as biofilms. They are embedded in polymeric structural scaffolds serve as a dynamic milieu for intercellular communication through physical and chemical signalling. Deciphering microbial ecology of biofilms in various natural or engineered settings has revealed co-existence of microorganisms from all domains of life, including Bacteria, Archaea and Eukarya. The coexistence of these dynamic microbes is not arbitrary, as a highly coordinated architectural setup and physiological complexity show ecological interdependence and myriads of underlying interactions. In this review, we describe how species from different kingdoms interact in biofilms and discuss the functional consequences of such interactions. We highlight metabolic advances of collaboration among species from different kingdoms, and advocate that these interactions are of great importance and need to be addressed in future research. Since trans-kingdom biofilms impact diverse contexts, ranging from complicated infections to efficient growth of plants, future knowledge within this field will be beneficial for medical microbiology, biotechnology, and our general understanding of microbial life in nature.
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Affiliation(s)
- Faizan Ahmed Sadiq
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.,Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Technology & Food Sciences Unit, Melle, Belgium
| | - Mads Frederik Hansen
- Section of Microbiology, Department of Biology, University of Copenhagen, Denmark
| | - Mette Burmølle
- Section of Microbiology, Department of Biology, University of Copenhagen, Denmark
| | - Marc Heyndrickx
- Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Technology & Food Sciences Unit, Melle, Belgium.,Department of Pathology, Bacteriology and Poultry Diseases, Ghent University, Merelbeke, Belgium
| | - Steve Flint
- School of Food and Advanced Technology, Massey University, Private Bag, 11222, Palmerston North, New Zealand
| | - Wenwei Lu
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.,State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Wei Chen
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.,State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China.,National Engineering Research Center for Functional Food, Jiangnan University, Wuxi 214122, China
| | - Hao Zhang
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.,State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China.,National Engineering Research Center for Functional Food, Jiangnan University, Wuxi 214122, China
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