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Marunga J, Kang Y, Goo E, Hwang I. Hierarchical regulation of Burkholderia glumae type III secretion system by GluR response regulator and Lon protease. MOLECULAR PLANT PATHOLOGY 2022; 23:1461-1471. [PMID: 35717678 PMCID: PMC9452761 DOI: 10.1111/mpp.13241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 05/25/2022] [Accepted: 05/25/2022] [Indexed: 06/15/2023]
Abstract
Expression of type III secretion system (T3SS) genes, which are important for the virulence of phytopathogenic bacteria, is induced in the plant apoplastic environment or artificially amended growth conditions. Wild-type Burkholderia glumae BGR1, which causes rice panicle blight, induced a hypersensitive response (HR) in tobacco plants, whereas the T3SS genes were not significantly expressed in the commonly used hrp induction medium. T3SS gene expression in B. glumae was dependent on HrpB, a well known T3SS gene transcriptional regulator. Here, we report a stepwise mechanism of T3SS gene regulation by the GluR response regulator and Lon protease in addition to HrpB-mediated control of T3SS genes in B. glumae. The gluR mutant showed no HR in tobacco plants and exhibited attenuated virulence in rice plants. GluR directly activated hrpB expression, indicating that hrpB belongs to the GluR regulon. The lon mutation allowed high expression of the T3SS genes in nutrient-rich media. Lon directly activated gluR expression but repressed hrpB expression, indicating that Lon acts as a regulator rather than a protease. However, the lon mutant failed to induce an HR and virulence, suggesting that Lon not only acts as a negative regulator, but also has an essential, yet to be determined role for T3SS. Our results demonstrate the involvement of the two-component system response regulator GluR and Lon in T3SS gene regulation, providing new insight into the complex interplay mechanisms of regulators involved in T3SS gene expression in bacteria-plant interactions.
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Affiliation(s)
- Joan Marunga
- Department of Agricultural BiotechnologySeoul National UniversitySeoulRepublic of Korea
| | - Yongsung Kang
- Department of Agricultural BiotechnologySeoul National UniversitySeoulRepublic of Korea
- Research Institute of Agriculture and Life SciencesSeoul National UniversitySeoulRepublic of Korea
| | - Eunhye Goo
- Department of Agricultural BiotechnologySeoul National UniversitySeoulRepublic of Korea
- Research Institute of Agriculture and Life SciencesSeoul National UniversitySeoulRepublic of Korea
| | - Ingyu Hwang
- Department of Agricultural BiotechnologySeoul National UniversitySeoulRepublic of Korea
- Research Institute of Agriculture and Life SciencesSeoul National UniversitySeoulRepublic of Korea
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2
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Alviz-Gazitua P, González A, Lee MR, Aranda CP. Molecular Relationships in Biofilm Formation and the Biosynthesis of Exoproducts in Pseudoalteromonas spp. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2022; 24:431-447. [PMID: 35486299 DOI: 10.1007/s10126-022-10097-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 01/21/2022] [Indexed: 06/14/2023]
Abstract
Most members of the Pseudoalteromonas genus have been isolated from living surfaces as members of epiphytic and epizooic microbiomes on marine macroorganisms. Commonly Pseudoalteromonas isolates are reported as a source of bioactive exoproducts, i.e., secondary metabolites, such as exopolymeric substances and extracellular enzymes. The experimental conditions for the production of these agents are commonly associated with sessile metabolic states such as biofilms or liquid cultures in the stationary growth phase. Despite this, the molecular mechanisms that connect biofilm formation and the biosynthesis of exoproducts in Pseudoalteromonas isolates have rarely been mentioned in the literature. This review compiles empirical evidence about exoproduct biosynthesis conditions and molecular mechanisms that regulate sessile metabolic states in Pseudoalteromonas species, to provide a comprehensive perspective on the regulatory convergences that generate the recurrent coexistence of both phenomena in this bacterial genus. This synthesis aims to provide perspectives on the extent of this phenomenon for the optimization of bioprospection studies and biotechnology processes based on these bacteria.
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Affiliation(s)
- P Alviz-Gazitua
- Departamento de Ciencias Biológicas y Biodiversidad, Universidad de Los Lagos, Avda. Fuchslocher 1305, P. Box 5290000, Osorno, Chile
| | - A González
- Departamento de Ciencias Biológicas y Biodiversidad, Universidad de Los Lagos, Avda. Fuchslocher 1305, P. Box 5290000, Osorno, Chile
| | - M R Lee
- Centro i~mar, Universidad de Los Lagos, Camino a Chinquihue km 6, P. Box 5480000, Puerto Montt, Chile
| | - C P Aranda
- Departamento de Ciencias Biológicas y Biodiversidad, Universidad de Los Lagos, Avda. Fuchslocher 1305, P. Box 5290000, Osorno, Chile.
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3
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Zhang Y, Deng Y, Feng J, Hu J, Chen H, Guo Z, Su Y. LuxS modulates motility and secretion of extracellular protease in fish pathogen Vibrio harveyi. Can J Microbiol 2021; 68:215-226. [PMID: 34855458 DOI: 10.1139/cjm-2021-0311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In this study, an in-frame deletion of the luxS gene was constructed to reveal the role of LuxS in the physiology and virulence of V. harveyi. The statistical analysis showed no significant differences in the growth ability, biofilm formation, antibiotic susceptibility, virulence by intraperitoneal injection, and the ability of V. harveyi to colonize the spleen and liver of the pearl gentian grouper between the wild-type (WT) and the luxS mutant. However, the deletion of luxS decreased the secretion of extracellular protease, while increased the ability of swimming and swarming. Simultaneously, a luxS-deleted mutant showed overproduction of lateral flagella, and an intact luxS complemented the defect. Since motility is flagella dependent, 16 of V. harveyi flagella biogenesis related genes were selected for further analysis. Based on quantitative real-time reverse transcription-PCR (qRT-PCR), the expression levels of these genes, including the polar flagella genes flaB, flhA, flhF, flhB, flhF, fliS, and flrA and the lateral flagella genes flgA, flgB, fliE, fliF, lafA, lafK, and motY, were significantly up-regulated in the ΔluxS: pMMB207 (ΔluxS+) strain as compared with the V. harveyi 345: pMMB207 (WT+) and C-ΔluxS strains during the early, mid-exponential, and stationary growth phase.
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Affiliation(s)
- Yaqiu Zhang
- South China Sea Fisheries Research Institute, 271781, Guangzhou, Guangdong, China;
| | - Yiqing Deng
- South China Sea Fisheries Research Institute, 271781, Guangzhou, Guangdong, China;
| | - Juan Feng
- South China Sea Fisheries Research Institute, 271781, Guangzhou, Guangdong, China;
| | - Jianmei Hu
- South China Sea Fisheries Research Institute, 271781, Guangzhou, Guangdong, China;
| | - Haoxiang Chen
- South China Sea Fisheries Research Institute, 271781, Guangzhou, Guangdong, China;
| | - Zhixun Guo
- South China Sea Fisheries Research Institute, 271781, Guangzhou, Guangdong, China;
| | - Youlu Su
- Zhongkai University of Agriculture and Engineering, 47894, Guangzhou, China, 510225;
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Nam Y, Goo E, Kang Y, Hwang I. Membrane Depolarization and Apoptosis-Like Cell Death in an Alkaline Environment in the Rice Pathogen Burkholderia glumae. Front Microbiol 2021; 12:755596. [PMID: 34712216 PMCID: PMC8546246 DOI: 10.3389/fmicb.2021.755596] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 09/15/2021] [Indexed: 11/13/2022] Open
Abstract
The rice pathogen Burkholderia glumae uses amino acids as a principal carbon source and thus produces ammonia in amino acid-rich culture medium such as Luria-Bertani (LB) broth. To counteract ammonia-mediated environmental alkaline toxicity, the bacterium produces a public good, oxalate, in a quorum sensing (QS)-dependent manner. QS mutants of B. glumae experience alkaline toxicity and may undergo cell death at the stationary phase when grown in LB medium. Here, we show that the cell-death processes of QS mutants due to alkaline environmental conditions are similar to the apoptosis-like cell death reported in other bacteria. Staining QS mutants with bis-(1,3-dibutylbarbituric acid)-trimethine oxonol revealed membrane depolarization. CellROX™ staining showed excessive generation of reactive oxygen species (ROS) in QS mutants. The expression of genes encoding HNH endonuclease (BGLU_1G15690), oligoribonuclease (BGLU_1G09120), ribonuclease E (BGLU_1G09400), and Hu-beta (BGLU_1G13530) was significantly elevated in QS mutants compared to that in wild-type BGR1, consistent with the degradation of cellular materials as observed under transmission electron microscopy (TEM). A homeostatic neutral pH was not attainable by QS mutants grown in LB broth or by wild-type BGR1 grown in an artificially amended alkaline environment. At an artificially adjusted alkaline pH, wild-type BGR1 underwent apoptosis-like cell death similar to that observed in QS mutants. These results show that environmental alkaline stress interferes with homeostatic neutral cellular pH, induces membrane depolarization, and causes apoptosis-like cell death in B. glumae.
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Affiliation(s)
- Yewon Nam
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
| | - Eunhye Goo
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea.,Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, South Korea
| | - Yongsung Kang
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea.,Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, South Korea
| | - Ingyu Hwang
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea.,Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, South Korea
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Bouteiller M, Dupont C, Bourigault Y, Latour X, Barbey C, Konto-Ghiorghi Y, Merieau A. Pseudomonas Flagella: Generalities and Specificities. Int J Mol Sci 2021; 22:ijms22073337. [PMID: 33805191 PMCID: PMC8036289 DOI: 10.3390/ijms22073337] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 03/22/2021] [Accepted: 03/22/2021] [Indexed: 12/21/2022] Open
Abstract
Flagella-driven motility is an important trait for bacterial colonization and virulence. Flagella rotate and propel bacteria in liquid or semi-liquid media to ensure such bacterial fitness. Bacterial flagella are composed of three parts: a membrane complex, a flexible-hook, and a flagellin filament. The most widely studied models in terms of the flagellar apparatus are E. coli and Salmonella. However, there are many differences between these enteric bacteria and the bacteria of the Pseudomonas genus. Enteric bacteria possess peritrichous flagella, in contrast to Pseudomonads, which possess polar flagella. In addition, flagellar gene expression in Pseudomonas is under a four-tiered regulatory circuit, whereas enteric bacteria express flagellar genes in a three-step manner. Here, we use knowledge of E. coli and Salmonella flagella to describe the general properties of flagella and then focus on the specificities of Pseudomonas flagella. After a description of flagellar structure, which is highly conserved among Gram-negative bacteria, we focus on the steps of flagellar assembly that differ between enteric and polar-flagellated bacteria. In addition, we summarize generalities concerning the fuel used for the production and rotation of the flagellar macromolecular complex. The last part summarizes known regulatory pathways and potential links with the type-six secretion system (T6SS).
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Affiliation(s)
- Mathilde Bouteiller
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (C.D.); (Y.B.); (X.L.); (C.B.); (Y.K.-G.)
- SFR NORVEGE, Structure Fédérative de Recherche Normandie Végétale, FED 4277, 76821 Mont-Saint-Aignan, France
| | - Charly Dupont
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (C.D.); (Y.B.); (X.L.); (C.B.); (Y.K.-G.)
- SFR NORVEGE, Structure Fédérative de Recherche Normandie Végétale, FED 4277, 76821 Mont-Saint-Aignan, France
| | - Yvann Bourigault
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (C.D.); (Y.B.); (X.L.); (C.B.); (Y.K.-G.)
- SFR NORVEGE, Structure Fédérative de Recherche Normandie Végétale, FED 4277, 76821 Mont-Saint-Aignan, France
| | - Xavier Latour
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (C.D.); (Y.B.); (X.L.); (C.B.); (Y.K.-G.)
- SFR NORVEGE, Structure Fédérative de Recherche Normandie Végétale, FED 4277, 76821 Mont-Saint-Aignan, France
| | - Corinne Barbey
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (C.D.); (Y.B.); (X.L.); (C.B.); (Y.K.-G.)
- SFR NORVEGE, Structure Fédérative de Recherche Normandie Végétale, FED 4277, 76821 Mont-Saint-Aignan, France
| | - Yoan Konto-Ghiorghi
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (C.D.); (Y.B.); (X.L.); (C.B.); (Y.K.-G.)
- SFR NORVEGE, Structure Fédérative de Recherche Normandie Végétale, FED 4277, 76821 Mont-Saint-Aignan, France
| | - Annabelle Merieau
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (C.D.); (Y.B.); (X.L.); (C.B.); (Y.K.-G.)
- SFR NORVEGE, Structure Fédérative de Recherche Normandie Végétale, FED 4277, 76821 Mont-Saint-Aignan, France
- Correspondence:
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Kim N, Mannaa M, Kim J, Ra JE, Kim SM, Lee C, Lee HH, Seo YS. The In Vitro and In Planta Interspecies Interactions Among Rice-Pathogenic Burkholderia Species. PLANT DISEASE 2021; 105:134-143. [PMID: 33197363 DOI: 10.1094/pdis-06-20-1252-re] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Burkholderia glumae, B. plantarii, and B. gladioli are responsible for serious diseases in rice crops and co-occurrence among them has been reported. In this study, in vitro assays revealed antagonistic activity among these organisms, with B. gladioli demonstrating strong inhibition of B. glumae and B. plantarii. Strains of B. glumae and B. plantarii that express green fluorescent protein were constructed and used for cocultivation assays with B. gladioli, which confirmed the strong inhibitory activity of B. gladioli. Cell-free supernatants from each species were tested against cultures of counterpart species to evaluate the potential to inhibit bacterial growth. To investigate the inhibitory activity of B. gladioli on B. glumae and B. plantarii in rice, rice plant assays were performed and quantitative PCR (qPCR) assays were developed for in planta bacterial quantification. The results indicated that coinoculation with B. gladioli leads to significantly reduced disease severity and colonization of rice tissues compared with single inoculation with B. glumae or B. plantarii. This study demonstrates the interactions among three rice-pathogenic Burkholderia species and strong antagonistic activity of B. gladioli in vitro and in planta. The qPCR assays developed here could be applied for accurate quantification of these organisms from in planta samples in future studies.
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Affiliation(s)
- Namgyu Kim
- Department of Microbiology, Pusan National University, Busan 46241, Korea
- Department of Integrated Biological Science, Pusan National University, Busan 46241, Korea
| | - Mohamed Mannaa
- Department of Microbiology, Pusan National University, Busan 46241, Korea
- Department of Integrated Biological Science, Pusan National University, Busan 46241, Korea
| | - Juyun Kim
- Department of Microbiology, Pusan National University, Busan 46241, Korea
- Department of Integrated Biological Science, Pusan National University, Busan 46241, Korea
| | - Ji-Eun Ra
- Crop Foundation Division, National Institute of Crop Science, Rural Development Administration, Wanju 55365, Korea
| | - Sang-Min Kim
- Crop Foundation Division, National Institute of Crop Science, Rural Development Administration, Wanju 55365, Korea
| | - Chaeyeong Lee
- Department of Microbiology, Pusan National University, Busan 46241, Korea
- Department of Integrated Biological Science, Pusan National University, Busan 46241, Korea
| | - Hyun-Hee Lee
- Department of Microbiology, Pusan National University, Busan 46241, Korea
- Department of Integrated Biological Science, Pusan National University, Busan 46241, Korea
| | - Young-Su Seo
- Department of Microbiology, Pusan National University, Busan 46241, Korea
- Department of Integrated Biological Science, Pusan National University, Busan 46241, Korea
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7
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Kwak GY, Goo E, Jeong H, Hwang I. Adverse effects of adaptive mutation to survive static culture conditions on successful fitness of the rice pathogen Burkholderia glumae in a host. PLoS One 2020; 15:e0238151. [PMID: 32833990 PMCID: PMC7444824 DOI: 10.1371/journal.pone.0238151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 08/10/2020] [Indexed: 11/18/2022] Open
Abstract
Bacteria often possess relatively flexible genome structures and adaptive genetic variants that allow survival in unfavorable growth conditions. Bacterial survival tactics in disadvantageous microenvironments include mutations that are beneficial against threats in their niche. Here, we report that the aerobic rice bacterial pathogen Burkholderia glumae BGR1 changes a specific gene for improved survival in static culture conditions. Static culture triggered formation of colony variants with deletions or point mutations in the gene bspP (BGLU_RS28885), which putatively encodes a protein that contains PDC2, PAS-9, SpoIIE, and HATPase domains. The null mutant of bspP survived longer in static culture conditions and produced a higher level of bis-(3'-5')-cyclic dimeric guanosine monophosphate than the wild type. Expression of the bacterial cellulose synthase regulator (bcsB) gene was upregulated in the mutant, consistent with the observation that the mutant formed pellicles faster than the wild type. Mature pellicle formation was observed in the bspP mutant before pellicle formation in wild-type BGR1. However, the population density of the bspP null mutant decreased substantially when grown in Luria-Bertani medium with vigorous agitation due to failure of oxalate-mediated detoxification of the alkaline environment. The bspP null mutant was less virulent and exhibited less effective colonization of rice plants than the wild type. All phenotypes caused by mutations in bspP were recovered to those of the wild type by genetic complementation. Thus, although wild-type B. glumae BGR1 prolonged viability by spontaneous mutation under static culture conditions, such genetic changes negatively affected colonization in rice plants. These results suggest that adaptive gene sacrifice of B. glumae to survive unfavorable growth conditions is not always desirable as it can adversely affect adaptability in the host.
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Affiliation(s)
- Gi-Young Kwak
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
| | - Eunhye Goo
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
| | - Haeyoon Jeong
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
| | - Ingyu Hwang
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea
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Peng J, Lelis T, Chen R, Barphagha I, Osti S, Ham JH. tepR encoding a bacterial enhancer-binding protein orchestrates the virulence and interspecies competition of Burkholderia glumae through qsmR and a type VI secretion system. MOLECULAR PLANT PATHOLOGY 2020; 21:1042-1054. [PMID: 32608174 PMCID: PMC7368122 DOI: 10.1111/mpp.12947] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 03/23/2020] [Accepted: 05/04/2020] [Indexed: 05/05/2023]
Abstract
The pathogenesis of the rice pathogenic bacterium Burkholderia glumae is under the tight regulation of the tofI/tofR quorum-sensing (QS) system. tepR, encoding a group I bacterial enhancer-binding protein, negatively regulates the production of toxoflavin, the phytotoxin acting as a major virulence factor in B. glumae. In this study, through a transcriptomic analysis, we identified the genes that were modulated by tepR and/or the tofI/tofR QS system. More than half of the differentially expressed genes, including the genes for the biosynthesis and transport of toxoflavin, were significantly more highly expressed in the ΔtepR mutant but less expressed in the ΔtofI-tofR (tofI/tofR QS-defective) mutant. In consonance with the transcriptome data, other virulence-related functions of B. glumae, extracellular protease activity and flagellum-dependent motility, were also negatively regulated by tepR, and this negative regulatory function of tepR was dependent on the IclR-type transcriptional regulator gene qsmR. Likewise, the ΔtepR mutant exhibited a higher level of heat tolerance in congruence with the higher transcription levels of heat shock protein genes in the mutant. Interestingly, tepR also exhibited its positive regulatory function on a previously uncharacterized type VI secretion system (denoted as BgT6SS-1). The survival of the both ΔtepR and ΔtssD (BgT6SS-1-defective) mutants was significantly compromised compared to the wild-type parent strain 336gr-1 in the presence of the natural rice-inhabiting bacterium, Pantoea sp. RSPAM1. Taken together, this study revealed pivotal regulatory roles of tepR in orchestrating multiple biological functions of B. glumae, including pathogenesis, heat tolerance, and bacterial interspecies competition.
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Affiliation(s)
- Jingyu Peng
- Department of Plant Pathology and Crop PhysiologyLouisiana State University Agricultural CenterBaton RougeLAUSA
- Present address:
Department of Plant, Soil, and Microbial SciencesMichigan State UniversityEast LansingMI48824USA
| | - Tiago Lelis
- Department of Plant Pathology and Crop PhysiologyLouisiana State University Agricultural CenterBaton RougeLAUSA
- Tropical Research and Education CenterInstitute of Food and Agriculture SciencesUniversity of FloridaHomesteadFLUSA
| | - Ruoxi Chen
- Department of Plant Pathology and Crop PhysiologyLouisiana State University Agricultural CenterBaton RougeLAUSA
- Present address:
1501 Capitol AvenueSacramentoCA95814USA
| | - Inderjit Barphagha
- Department of Plant Pathology and Crop PhysiologyLouisiana State University Agricultural CenterBaton RougeLAUSA
| | - Surendra Osti
- Department of Plant Pathology and Crop PhysiologyLouisiana State University Agricultural CenterBaton RougeLAUSA
- Present address:
Department of Agricultural Economics and AgribusinessLouisiana State UniversityBaton RougeLA70803USA
| | - Jong Hyun Ham
- Department of Plant Pathology and Crop PhysiologyLouisiana State University Agricultural CenterBaton RougeLAUSA
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Gnanasekaran G, Lim JY, Hwang I. Disappearance of Quorum Sensing in Burkholderia glumae During Experimental Evolution. MICROBIAL ECOLOGY 2020; 79:947-959. [PMID: 31828389 DOI: 10.1007/s00248-019-01445-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 09/20/2019] [Indexed: 06/10/2023]
Abstract
The plant pathogen Burkholderia glumae uses quorum sensing (QS) that allows bacteria to share information and alter gene expression on the basis of cell density. The wild-type strain of B. glumae produces quorum-sensing signals (autoinducers) to detect their community and upregulate QS-dependent genes across the population for performing social and group behaviors. The model organism B. glumae was selected to investigate adaptation, estimate evolutionary parameters, and test diverse evolutionary hypotheses by using experimental evolution. The wild-type B. glumae virulent strain showed genotypic changes during regular subculture due to oxygen limitation. The laboratory-evolved clones failed to produce the signaling molecule of C8-HSL/C6-HSL for activation of the quorum-sensing system. Further, the laboratory-evolved clones failed to produce catalase and oxalate for protecting themselves from the toxic environment at stationary phase and phytotoxins (toxoflavin) for infecting rice grain, respectively. The laboratory-evolved clones were completely sequenced and compared with the wild-type. Sequencing analysis of the evolved clones revealed that mutations in QS-responsible genes (iclR), sensor genes (shk, mcp), and signaling genes (luxR) were responsible for quorum-sensing activity failure. The experimental results and sequencing analysis revealed quorum-sensing process failure in the laboratory-evolved clones. In conclusion, the wild-type B. glumae strain was often exposed to oxidative stress during regular subculture and evolved as an avirulent strain (quorum-sensing mutant) by losing the phenotypic and genotypic characteristics.
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Affiliation(s)
- Gopalsamy Gnanasekaran
- Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea.
| | - Jae Yun Lim
- Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea
| | - Ingyu Hwang
- Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea
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10
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Kwak GY, Choi O, Goo E, Kang Y, Kim J, Hwang I. Quorum Sensing-Independent Cellulase-Sensitive Pellicle Formation Is Critical for Colonization of Burkholderia glumae in Rice Plants. Front Microbiol 2020; 10:3090. [PMID: 32010117 PMCID: PMC6978641 DOI: 10.3389/fmicb.2019.03090] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 12/20/2019] [Indexed: 01/19/2023] Open
Abstract
Bacteria form biofilms as a means to adapt to environmental changes for survival. Pellicle is a floating biofilm formed at the air-liquid interface in static culture conditions; however, its functional roles have received relatively little attention compared to solid surface-associated biofilms in gram-negative bacteria. Here we show that the rice pathogen Burkholderia glumae BGR1 forms cellulase-sensitive pellicles in a bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP)- and flagellum-dependent, but quorum sensing (QS)-independent, manner. Pellicle formation was more favorable at 28°C than at the optimum growth temperature (37°C), and was facilitated by constitutive expression of pelI, a diguanylate cyclase gene from B. glumae, or pleD, the GGDEF response regulator from Agrobacterium tumefaciens. Constitutive expression of pelI or pleD raised the levels of c-di-GMP, facilitated pellicle formation, and suppressed swarming motility in B. glumae. QS-defective mutants of B. glumae formed pellicles, while flagellum-defective mutants did not. Pellicles of B. glumae were sensitive to cellulase but not to proteinase K or DNase I. A gene cluster containing seven genes involved in bacterial cellulose biosynthesis, bcsD, bcsR, bcsQ, bcsA, bcsB, bcsZ, and bcsC, homologous to known genes involved in cellulose biosynthesis in other bacteria, was identified in B. glumae. Mutations in each gene abolished pellicle formation. These results revealed a positive correlation between cellulase-sensitive pellicles and putative cellulose biosynthetic genes. Pellicle-defective mutants did not colonize as successfully as the wild-type strain BGR1 in rice plants, which resulted in a significant reduction in virulence. Our findings show that cellulase-sensitive pellicles produced in a QS-independent manner play important roles in the interactions between rice plants and B. glumae.
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Affiliation(s)
- Gi-Young Kwak
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
| | - Okhee Choi
- Division of Applied Life Science, Institute of Agriculture and Life Sciences, Gyeongsang National University, Jinju, South Korea
| | - Eunhye Goo
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
| | - Yongsung Kang
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
| | - Jinwoo Kim
- Division of Applied Life Science, Institute of Agriculture and Life Sciences, Gyeongsang National University, Jinju, South Korea
| | - Ingyu Hwang
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, South Korea
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11
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Lee C, Mannaa M, Kim N, Kim J, Choi Y, Kim SH, Jung B, Lee HH, Lee J, Seo YS. Stress Tolerance and Virulence-Related Roles of Lipopolysaccharide in Burkholderia glumae. THE PLANT PATHOLOGY JOURNAL 2019; 35:445-458. [PMID: 31632220 PMCID: PMC6788416 DOI: 10.5423/ppj.oa.04.2019.0124] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 06/26/2019] [Accepted: 07/02/2019] [Indexed: 05/10/2023]
Abstract
The lipopolysaccharide (LPS) composed of lipid A, core, and O-antigen is the fundamental constituent of the outer membrane in gram-negative bacteria. This study was conducted to investigate the roles of LPS in Burkholderia glumae, the phytopathogen causing bacterial panicle blight and seedling rot in rice. To study the roles of the core oligosaccharide (OS) and the O-antigen region, mutant strains targeting the waaC and the wbiFGHI genes were generated. The LPS profile was greatly affected by disruption of the waaC gene and slight reductions were observed in the O-antigen region following wbiFGHI deletions. The results indicated that disruption in the core OS biosynthesis-related gene, waaC, was associated with increased sensitivity to environmental stress conditions including acidic, osmotic, saline, and detergent stress, and to polymyxin B. Moreover, significant impairment in the swimming and swarming motility and attenuation of bacterial virulence to rice were also observed in the waaC-defective mutant. The motility and virulence of O-antigen mutants defective in any gene of the wbiFGHI operon, were not significantly different from the wild-type except in slight decrease in swimming and swarming motility with wbiH deletion. Altogether, the results of present study indicated that the LPS, particularly the core OS region, is required for tolerance to environmental stress and full virulence in B. glumae. To our knowledge, this is the first functional study of LPS in a plant pathogenic Burkholderia sp. and presents a step forward toward full understanding of B. glumae pathogenesis.
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Affiliation(s)
- Chaeyeong Lee
- Department of Microbiology, Pusan National University, Busan 46241,
Korea
- Department of Integrated Biological Science, Pusan National University, Busan 46241,
Korea
| | - Mohamed Mannaa
- Department of Microbiology, Pusan National University, Busan 46241,
Korea
- Department of Integrated Biological Science, Pusan National University, Busan 46241,
Korea
| | - Namgyu Kim
- Department of Microbiology, Pusan National University, Busan 46241,
Korea
- Department of Integrated Biological Science, Pusan National University, Busan 46241,
Korea
| | - Juyun Kim
- Department of Microbiology, Pusan National University, Busan 46241,
Korea
- Department of Integrated Biological Science, Pusan National University, Busan 46241,
Korea
| | - Yeounju Choi
- Department of Microbiology, Pusan National University, Busan 46241,
Korea
- Department of Integrated Biological Science, Pusan National University, Busan 46241,
Korea
| | - Soo Hyun Kim
- Department of Microbiology, Pusan National University, Busan 46241,
Korea
- Department of Integrated Biological Science, Pusan National University, Busan 46241,
Korea
| | - Boknam Jung
- Department of Applied Biology, Dong-A University, Busan 49315,
Korea
| | - Hyun-Hee Lee
- Department of Microbiology, Pusan National University, Busan 46241,
Korea
- Department of Integrated Biological Science, Pusan National University, Busan 46241,
Korea
| | - Jungkwan Lee
- Department of Applied Biology, Dong-A University, Busan 49315,
Korea
| | - Young-Su Seo
- Department of Microbiology, Pusan National University, Busan 46241,
Korea
- Department of Integrated Biological Science, Pusan National University, Busan 46241,
Korea
- Corresponding author.: Phone) +82-51-510-2267, FAX) +82-51-514-1778, E-mail)
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12
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Yu Z, Yu D, Mao Y, Zhang M, Ding M, Zhang J, Wu S, Qiu J, Yin J. Identification and characterization of a LuxI/R-type quorum sensing system in Pseudoalteromonas. Res Microbiol 2019; 170:243-255. [DOI: 10.1016/j.resmic.2019.07.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 07/04/2019] [Accepted: 07/09/2019] [Indexed: 12/30/2022]
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13
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Lelis T, Peng J, Barphagha I, Chen R, Ham JH. The Virulence Function and Regulation of the Metalloprotease Gene prtA in the Plant-Pathogenic Bacterium Burkholderia glumae. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2019; 32:841-852. [PMID: 30694091 DOI: 10.1094/mpmi-11-18-0312-r] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Bacterial panicle blight caused by Burkholderia glumae is a major bacterial disease of rice. Our preliminary RNA-seq study showed that a serine metalloprotease gene, prtA, is regulated in a similar manner to the genes for the biosynthesis and transport of toxoflavin, which is a known major virulence factor of B. glumae. prtA null mutants of the virulent strain B. glumae 336gr-1 did not show a detectable extracellular protease activity, indicating that prtA is the solely responsible gene for the extracellular protease activity detected from this bacterium. In addition, inoculation of rice panicles with the prtA mutants resulted in a significant reduction of disease severity compared with the wild-type parent strain, suggesting the requirement of prtA for the full virulence of B. glumae. A double mutant deficient in both serine metalloprotease and toxoflavin (ΔtoxA/prtA-) exhibited a further numeric but not statistically significant decrease of disease development compared with the ΔtoxA strain. Both the prtA-driven extracellular protease activity and the toxoflavin production were dependent on both the tofI/tofR quorum-sensing and the global regulatory gene qsmR, indicating the important roles of the two global regulatory factors for the bacterial pathogenesis by this pathogen.
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Affiliation(s)
- Tiago Lelis
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, U.S.A
| | - Jingyu Peng
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, U.S.A
| | - Inderjit Barphagha
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, U.S.A
| | - Ruoxi Chen
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, U.S.A
| | - Jong Hyun Ham
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, U.S.A
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14
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Seynos-García E, Castañeda-Lucio M, Muñoz-Rojas J, López-Pliego L, Villalobos M, Bustillos-Cristales R, Fuentes-Ramírez LE. Loci Identification of a N-acyl Homoserine Lactone Type Quorum Sensing System and a New LysR-type Transcriptional Regulator Associated with Antimicrobial Activity and Swarming in Burkholderia Gladioli UAPS07070. Open Life Sci 2019; 14:165-178. [PMID: 33817149 PMCID: PMC7874821 DOI: 10.1515/biol-2019-0019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 01/14/2019] [Indexed: 12/23/2022] Open
Abstract
A random transposition mutant library of B. gladioli UAPS07070 was analyzed for searching mutants with impaired microbial antagonism. Three derivates showed diminished antimicrobial activity against a sensitive strain. The mutated loci showed high similarity to the quorum sensing genes of the AHL-synthase and its regulator. Another mutant was affected in a gene coding for a LysrR-type transcriptional regulator. The production of toxoflavin, the most well known antimicrobial-molecule and a major virulence factor of plant-pathogenic B. glumae and B. gladioli was explored. The absence of a yellowish pigment related to toxoflavin and the undetectable transcription of toxA in the mutants indicated the participation of the QS system and of the LysR-type transcriptional regulator in the regulation of toxoflavin. Additionally, those genes were found to be related to the swarming phenotype. Lettuce inoculated with the AHL synthase and the lysR mutants showed less severe symptoms. We present evidence of the participation of both, the quorum sensing and for the first time, of a LysR-type transcriptional regulator in antibiosis and swarming phenotype in a strain of B. gladioli
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Affiliation(s)
- E Seynos-García
- Lab. Ecología Molecular Microbiana, Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla. Edif. IC11, Ciudad Universitaria, CP 72570, Puebla, Puebla, México
| | - M Castañeda-Lucio
- Lab. Ecología Molecular Microbiana, Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla. Edif. IC11, Ciudad Universitaria, CP 72570, Puebla, Puebla, México
| | - J Muñoz-Rojas
- Lab. Ecología Molecular Microbiana, Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla. Edif. IC11, Ciudad Universitaria, CP 72570, Puebla, Puebla, México
| | - L López-Pliego
- Lab. Ecología Molecular Microbiana, Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla. Edif. IC11, Ciudad Universitaria, CP 72570, Puebla, Puebla, México
| | - M Villalobos
- Centro de Investigación en Biotecnología Aplicada-Instituto Politécnico Nacional, Carretera Estatal Sta Inés Tecuexcomac‑Tepetitla, km. 1.5, C.P: 90700 Tepetitla de Lárdizabal, Tlaxcala,Mexico
| | - R Bustillos-Cristales
- Lab. Ecología Molecular Microbiana, Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla. Edif. IC11, Ciudad Universitaria, CP 72570, Puebla, Puebla, México
| | - L E Fuentes-Ramírez
- Lab. Ecología Molecular Microbiana, Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla. Edif. IC11, Ciudad Universitaria, CP 72570, Puebla, Puebla, México
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15
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Sibanda S, Kwenda S, Tanui CK, Shyntum DY, Coutinho TA, Moleleki LN. Transcriptome Profiling Reveals the EanI/R Quorum Sensing Regulon in Pantoea Ananatis LMG 2665 T. Genes (Basel) 2018; 9:E148. [PMID: 29518982 PMCID: PMC5867869 DOI: 10.3390/genes9030148] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 02/26/2018] [Accepted: 03/01/2018] [Indexed: 11/23/2022] Open
Abstract
Pantoea ananatis LMG 2665T synthesizes and utilizes acyl homoserine lactones (AHLs) for signalling. The complete set of genes regulated by the EanI/R quorum sensing (QS) system in this strain is still not fully known. In this study, RNA-sequencing (RNA-seq) was used to identify the EanI/R regulon in LMG 2665T. Pairwise comparisons of LMG 2665T in the absence of AHLs (Optical density (OD)600 = 0.2) and in the presence of AHLs (OD600 = 0.5) were performed. Additionally, pairwise comparisons of LMG 2665T and its QS mutant at OD600 = 0.5 were undertaken. In total, 608 genes were differentially expressed between LMG 2665T at OD600 = 0.5 versus the same strain at OD600 = 0.2 and 701 genes were differentially expressed between LMG 2665T versus its QS mutant at OD600 = 0.5. A total of 196 genes were commonly differentially expressed between the two approaches. These constituted approximately 4.5% of the whole transcriptome under the experimental conditions used in this study. The RNA-seq data was validated by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR). Genes found to be regulated by EanI/R QS were those coding for redox sensing, metabolism, flagella formation, flagella dependent motility, cell adhesion, biofilm formation, regulators, transport, chemotaxis, methyl accepting proteins, membrane proteins, cell wall synthesis, stress response and a large number of hypothetical proteins. The results of this study give insight into the genes that are regulated by the EanI/R system in LMG 2665T. Functional characterization of the QS regulated genes in LMG 2665T could assist in the formulation of control strategies for this plant pathogen.
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Affiliation(s)
- Siphathele Sibanda
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), Faculty of Natural and Agricultural Sciences, University of Pretoria, 0002 Pretoria, South Africa.
- Centre for Microbial Ecology and Genomics (CMEG), Faculty of Natural and Agricultural Sciences, University of Pretoria, 0002 Pretoria, South Africa.
| | - Stanford Kwenda
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), Faculty of Natural and Agricultural Sciences, University of Pretoria, 0002 Pretoria, South Africa.
| | - Collins K Tanui
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), Faculty of Natural and Agricultural Sciences, University of Pretoria, 0002 Pretoria, South Africa.
| | - Divine Y Shyntum
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), Faculty of Natural and Agricultural Sciences, University of Pretoria, 0002 Pretoria, South Africa.
| | - Teresa A Coutinho
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), Faculty of Natural and Agricultural Sciences, University of Pretoria, 0002 Pretoria, South Africa.
- Centre for Microbial Ecology and Genomics (CMEG), Faculty of Natural and Agricultural Sciences, University of Pretoria, 0002 Pretoria, South Africa.
| | - Lucy N Moleleki
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), Faculty of Natural and Agricultural Sciences, University of Pretoria, 0002 Pretoria, South Africa.
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16
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Roux D, Schaefers M, Clark BS, Weatherholt M, Renaud D, Scott D, LiPuma JJ, Priebe G, Gerard C, Yoder-Himes DR. A putative lateral flagella of the cystic fibrosis pathogen Burkholderia dolosa regulates swimming motility and host cytokine production. PLoS One 2018; 13:e0189810. [PMID: 29346379 PMCID: PMC5773237 DOI: 10.1371/journal.pone.0189810] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 12/01/2017] [Indexed: 01/25/2023] Open
Abstract
Burkholderia dolosa caused an outbreak in the cystic fibrosis clinic at Boston Children's Hospital and was associated with high mortality in these patients. This species is part of a larger complex of opportunistic pathogens known as the Burkholderia cepacia complex (Bcc). Compared to other species in the Bcc, B. dolosa is highly transmissible; thus understanding its virulence mechanisms is important for preventing future outbreaks. The genome of one of the outbreak strains, AU0158, revealed a homolog of the lafA gene encoding a putative lateral flagellin, which, in other non-Bcc species, is used for movement on solid surfaces, attachment to host cells, or movement inside host cells. Here, we analyzed the conservation of the lafA gene and protein sequences, which are distinct from those of the polar flagella, and found lafA homologs to be present in numerous β-proteobacteria but notably absent from most other Bcc species. A lafA deletion mutant in B. dolosa showed a greater swimming motility than wild-type due to an increase in the number of polar flagella, but did not appear to contribute to biofilm formation, host cell invasion, or murine lung colonization or persistence over time. However, the lafA gene was important for cytokine production in human peripheral blood mononuclear cells, suggesting it may have a role in recognition by the human immune response.
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Affiliation(s)
- Damien Roux
- INSERM, IAME, UMR 1137, Paris, France
- Univ Paris Diderot, Sorbonne Paris Cité, Paris, France
- AP-HP, Louis Mourier Hospital, Intensive Care Unit, Colombes, France
| | - Matthew Schaefers
- Division of Critical Care Medicine, Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- Department of Anesthesia, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Bradley S. Clark
- Department of Biology, University of Louisville, Louisville, Kentucky, United States of America
| | - Molly Weatherholt
- Department of Biology, University of Louisville, Louisville, Kentucky, United States of America
| | - Diane Renaud
- Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, Kentucky, United States of America
| | - David Scott
- Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, Kentucky, United States of America
| | - John J. LiPuma
- Division of Pediatrics, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Gregory Priebe
- Division of Critical Care Medicine, Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- Department of Anesthesia, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Craig Gerard
- Division of Respiratory Diseases, Boston Children’s Hospital, Boston, Massachusetts, United States of America
| | - Deborah R. Yoder-Himes
- Department of Biology, University of Louisville, Louisville, Kentucky, United States of America
- * E-mail:
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17
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Schuster M, Sexton DJ, Hense BA. Why Quorum Sensing Controls Private Goods. Front Microbiol 2017; 8:885. [PMID: 28579979 PMCID: PMC5437708 DOI: 10.3389/fmicb.2017.00885] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 05/02/2017] [Indexed: 12/22/2022] Open
Abstract
Cell-cell communication, also termed quorum sensing (QS), is a widespread process that coordinates gene expression in bacterial populations. The generally accepted view is that QS optimizes the cell density-dependent benefit attained from cooperative behaviors, often in the form of secreted products referred to as "public goods." This view is challenged by an increasing number of cell-associated products or "private goods" reported to be under QS-control for which a collective benefit is not apparent. A prominent example is nucleoside hydrolase from Pseudomonas aeruginosa, a periplasmic enzyme that catabolizes adenosine. Several recent studies have shown that private goods can function to stabilize cooperation by co-regulated public goods, seemingly explaining their control by QS. Here we argue that this property is a by-product of selection for other benefits rather than an adaptation. Emphasizing ecophysiological context, we propose alternative explanations for the QS control of private goods. We suggest that the benefit attained from private goods is associated with high cell density, either because a relevant ecological condition correlates with density, or because the private good is, directly or indirectly, involved in cooperative behavior. Our analysis helps guide a systems approach to QS, with implications for antivirulence drug design and synthetic biology.
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Affiliation(s)
- Martin Schuster
- Department of Microbiology, Oregon State UniversityCorvallis, OR, United States
| | - D Joseph Sexton
- Department of Microbiology, Oregon State UniversityCorvallis, OR, United States
| | - Burkhard A Hense
- Institute of Computational Biology, Helmholtz Zentrum MünchenNeuherberg, Germany
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18
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Uzelac G, Patel HK, Devescovi G, Licastro D, Venturi V. Quorum sensing and RsaM regulons of the rice pathogen Pseudomonas fuscovaginae. MICROBIOLOGY-SGM 2017; 163:765-777. [PMID: 28530166 DOI: 10.1099/mic.0.000454] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Pseudomonas fuscovaginae (Pfv) is an emerging plant pathogen causing sheath brown rot in rice, as well as diseases in other gramineae food crops including maize, sorghum and wheat. Pfv possesses two conserved N-acyl homoserine lactone (AHL) quorum sensing (QS) systems called PfvI/R and PfsI/R, which are repressed by RsaL and RsaM, respectively. The two systems are not hierarchically organized and are involved in plant virulence. In this study the AHL QS PfsI/R, PfvI/R and RsaM regulons were determined by transcriptomic analysis. The PfsI/R system regulates 98 genes, whereas 26 genes are regulated by the PfvI/R AHL QS system; only two genes are regulated by both systems. RsaM, on the other hand, regulates over 400 genes: 206 are negatively regulated and 260 are positively regulated. More than half of the genes controlled by the PfsI/R system and 65 % by the PfvI/R system are also part of the RsaM regulon; this is due to RsaM being involved in the regulation of both systems. It is concluded that the two QS systems regulate a unique set of genes and that RsaM is a global regulator mediating the expression of different genes through the two QS systems as well as genes independently of QS.
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Affiliation(s)
- Gordana Uzelac
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Hitendra Kumar Patel
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy.,Present address: CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, India
| | - Giulia Devescovi
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | | | - Vittorio Venturi
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
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19
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Barahona E, Navazo A, Garrido-Sanz D, Muriel C, Martínez-Granero F, Redondo-Nieto M, Martín M, Rivilla R. Pseudomonas fluorescens F113 Can Produce a Second Flagellar Apparatus, Which Is Important for Plant Root Colonization. Front Microbiol 2016; 7:1471. [PMID: 27713729 PMCID: PMC5031763 DOI: 10.3389/fmicb.2016.01471] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 09/02/2016] [Indexed: 12/30/2022] Open
Abstract
The genomic sequence of Pseudomonas fluorescens F113 has shown the presence of a 41 kb cluster of genes that encode the production of a second flagellar apparatus. Among 2,535 pseudomonads strains with sequenced genomes, these genes are only present in the genomes of F113 and other six strains, all but one belonging to the P. fluorescens cluster of species, in the form of a genetic island. The genes are homologous to the flagellar genes of the soil bacterium Azotobacter vinelandii. Regulation of these genes is mediated by the flhDC master operon, instead of the typical regulation in pseudomonads, which is through fleQ. Under laboratory conditions, F113 does not produce this flagellum and the flhDC operon is not expressed. However, ectopic expression of the flhDC operon is enough for its production, resulting in a hypermotile strain. This flagellum is also produced under laboratory conditions by the kinB and algU mutants. Genetic analysis has shown that kinB strongly represses the expression of the flhDC operon. This operon is activated by the Vfr protein probably in a c-AMP dependent way. The strains producing this second flagellum are all hypermotile and present a tuft of polar flagella instead of the single polar flagellum produced by the wild-type strain. Phenotypic variants isolated from the rhizosphere produce this flagellum and mutation of the genes encoding it, results in a defect in competitive colonization, showing its importance for root colonization.
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Affiliation(s)
- Emma Barahona
- Departamento de Biología, Universidad Autónoma de Madrid Madrid, Spain
| | - Ana Navazo
- Departamento de Biología, Universidad Autónoma de Madrid Madrid, Spain
| | | | - Candela Muriel
- Departamento de Biología, Universidad Autónoma de Madrid Madrid, Spain
| | | | | | - Marta Martín
- Departamento de Biología, Universidad Autónoma de Madrid Madrid, Spain
| | - Rafael Rivilla
- Departamento de Biología, Universidad Autónoma de Madrid Madrid, Spain
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20
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Nickzad A, Déziel E. Adaptive Significance of Quorum Sensing-Dependent Regulation of Rhamnolipids by Integration of Growth Rate in Burkholderia glumae: A Trade-Off between Survival and Efficiency. Front Microbiol 2016; 7:1215. [PMID: 27540372 PMCID: PMC4972832 DOI: 10.3389/fmicb.2016.01215] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 07/21/2016] [Indexed: 01/18/2023] Open
Abstract
Quorum sensing (QS) is a cell density-dependent mechanism which enables a population of bacteria to coordinate cooperative behaviors in response to the accumulation of self-produced autoinducer signals in their local environment. An emerging framework is that the adaptive significance of QS in the regulation of production of costly extracellular metabolites ("public goods") is to maintain the homeostasis of cooperation. We investigated this model using the phytopathogenic bacterium Burkholderia glumae, which we have previously demonstrated uses QS to regulate the production of rhamnolipids, extracellular surface-active glycolipids promoting the social behavior called "swarming motility." Using mass spectrometric quantification and chromosomal lux-based gene expression, we made the unexpected finding that when unrestricted nutrient resources are provided, production of rhamnolipids is carried out completely independently of QS regulation. This is a unique observation among known QS-controlled factors in bacteria. On the other hand, under nutrient-limited conditions, QS then becomes the main regulating mechanism, significantly enhancing the specific rhamnolipids yield. Accordingly, decreasing nutrient concentrations amplifies rhamnolipid biosynthesis gene expression, revealing a system where QS-dependent regulation is specifically triggered by the growth rate of the population, rather than by its cell density. Furthermore, a gradual increase in QS signal specific concentration upon decrease of specific growth rate suggests a reduction in quorum threshold, which reflects an increase in cellular demand for production of QS-dependent target gene product at low density populations. Integration of growth rate with QS as a decision-making mechanism for biosynthesis of costly metabolites, such as rhamnolipids, could serve to assess the demand and timing for expanding the carrying capacity of a population through spatial expansion mechanisms, such as swarming motility, thus promoting the chances of survival, even if the cell density might not be high enough for an otherwise efficient production of rhamnolipids. In conclusion, we propose that the adaptive significance of growth rate-dependent functionality of QS in biosynthesis of costly public goods lies within providing a regulatory mechanism for selecting the optimal trade-off between survival and efficiency.
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Affiliation(s)
| | - Eric Déziel
- Institut National de la Recherche Scientifique – Institut Armand-Frappier, LavalQC, Canada
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21
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Kumar B, Cardona ST. Synthetic Cystic Fibrosis Sputum Medium Regulates Flagellar Biosynthesis through the flhF Gene in Burkholderia cenocepacia. Front Cell Infect Microbiol 2016; 6:65. [PMID: 27379216 PMCID: PMC4905959 DOI: 10.3389/fcimb.2016.00065] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 05/30/2016] [Indexed: 12/03/2022] Open
Abstract
Burkholderia cenocepacia belongs to the Burkholderia cepacia complex (Bcc), a group of at least 18 distinct species that establish chronic infections in the lung of people with the genetic disease cystic fibrosis (CF). The sputum of CF patients is rich in amino acids and was previously shown to increase flagellar gene expression in B. cenocepacia. We examined flagellin expression and flagellar morphology of B. cenocepacia grown in synthetic cystic fibrosis sputum medium (SCFM) compared to minimal medium. We found that CF nutritional conditions induce increased motility and flagellin expression. Individual amino acids added at the same concentrations as found in SCFM also increased motility but not flagellin expression, suggesting a chemotactic effect of amino acids. Electron microscopy and flagella staining demonstrated that the increase in flagellin corresponds to a change in the number of flagella per cell. In minimal medium, the ratio of multiple: single: aflagellated cells was 2:3.5:4.5; while under SCFM conditions, the ratio was 7:2:1. We created a deletion mutant, ΔflhF, to study whether this putative GTPase regulates the flagellation pattern of B. cenocepacia K56-2 during growth in CF conditions. The ΔflhF mutant exhibited 80% aflagellated, 14% single and 6% multiple flagellated bacterial subpopulations. Moreover, the ratio of multiple to single flagella in WT and ΔflhF was 3.5 and 0.43, respectively in CF conditions. The observed differences suggest that FlhF positively regulates flagellin expression and the flagellation pattern in B. cenocepacia K56-2 during CF nutritional conditions.
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Affiliation(s)
- Brijesh Kumar
- Department of Microbiology, University of Manitoba Winnipeg, MB, Canada
| | - Silvia T Cardona
- Department of Microbiology, University of ManitobaWinnipeg, MB, Canada; Department of Medical Microbiology and Infectious Diseases, University of ManitobaWinnipeg, MB, Canada
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22
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Naughton LM, An SQ, Hwang I, Chou SH, He YQ, Tang JL, Ryan RP, Dow JM. Functional and genomic insights into the pathogenesis of B
urkholderia
species to rice. Environ Microbiol 2016; 18:780-90. [DOI: 10.1111/1462-2920.13189] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 12/10/2015] [Accepted: 12/13/2015] [Indexed: 02/05/2023]
Affiliation(s)
- Lynn M. Naughton
- School of Microbiology; Biosciences Institute; University College Cork; Cork Ireland
| | - Shi-qi An
- Division of Molecular Microbiology; College of Life Sciences; University of Dundee; Dundee UK
| | - Ingyu Hwang
- Institute of Biochemistry and Department of Agricultural Biotechnology; Seoul National University; Seoul 151-921 South Korea
| | - Shan-Ho Chou
- National Chung Hsing University Biotechnology Center; National Chung Hsing University; Taichung 40227 Taiwan
| | - Yong-Qiang He
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources; The Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering; College of Life Science and Technology; Guangxi University; 100 Daxue Road Nanning Guangxi 530004 China
| | - Ji-Liang Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources; The Key Laboratory of Ministry of Education for Microbial and Plant Genetic Engineering; College of Life Science and Technology; Guangxi University; 100 Daxue Road Nanning Guangxi 530004 China
| | - Robert P. Ryan
- Division of Molecular Microbiology; College of Life Sciences; University of Dundee; Dundee UK
| | - J. Maxwell Dow
- School of Microbiology; Biosciences Institute; University College Cork; Cork Ireland
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23
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Gao R, Krysciak D, Petersen K, Utpatel C, Knapp A, Schmeisser C, Daniel R, Voget S, Jaeger KE, Streit WR. Genome-wide RNA sequencing analysis of quorum sensing-controlled regulons in the plant-associated Burkholderia glumae PG1 strain. Appl Environ Microbiol 2015; 81:7993-8007. [PMID: 26362987 PMCID: PMC4651095 DOI: 10.1128/aem.01043-15] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 09/01/2015] [Indexed: 01/16/2023] Open
Abstract
Burkholderia glumae PG1 is a soil-associated motile plant-pathogenic bacterium possessing a cell density-dependent regulation system called quorum sensing (QS). Its genome contains three genes, here designated bgaI1 to bgaI3, encoding distinct autoinducer-1 (AI-1) synthases, which are capable of synthesizing QS signaling molecules. Here, we report on the construction of B. glumae PG1 ΔbgaI1, ΔbgaI2, and ΔbgaI3 mutants, their phenotypic characterization, and genome-wide transcriptome analysis using RNA sequencing (RNA-seq) technology. Knockout of each of these bgaI genes resulted in strongly decreased motility, reduced extracellular lipase activity, a reduced ability to cause plant tissue maceration, and decreased pathogenicity. RNA-seq analysis of all three B. glumae PG1 AI-1 synthase mutants performed in the transition from exponential to stationary growth phase revealed differential expression of a significant number of predicted genes. In comparison with the levels of gene expression by wild-type strain B. glumae PG1, 481 genes were differentially expressed in the ΔbgaI1 mutant, 213 were differentially expressed in the ΔbgaI2 mutant, and 367 were differentially expressed in the ΔbgaI3 mutant. Interestingly, only a minor set of 78 genes was coregulated in all three mutants. The majority of the QS-regulated genes were linked to metabolic activities, and the most pronounced regulation was observed for genes involved in rhamnolipid and Flp pilus biosynthesis and the type VI secretion system and genes linked to a clustered regularly interspaced short palindromic repeat (CRISPR)-cas gene cluster.
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Affiliation(s)
- Rong Gao
- Biocenter Klein Flottbek, Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany
| | - Dagmar Krysciak
- Biocenter Klein Flottbek, Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany
| | - Katrin Petersen
- Biocenter Klein Flottbek, Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany
| | - Christian Utpatel
- Biocenter Klein Flottbek, Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany
| | - Andreas Knapp
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
| | - Christel Schmeisser
- Biocenter Klein Flottbek, Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany
| | - Rolf Daniel
- Department of Genomic and Applied Microbiology, Institute of Microbiology and Genetics, Georg August University Göttingen, Göttingen, Germany
| | - Sonja Voget
- Department of Genomic and Applied Microbiology, Institute of Microbiology and Genetics, Georg August University Göttingen, Göttingen, Germany
| | - Karl-Erich Jaeger
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany Institute of Bio- and Geosciences IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany
| | - Wolfgang R Streit
- Biocenter Klein Flottbek, Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany
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24
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Nickzad A, Lépine F, Déziel E. Quorum Sensing Controls Swarming Motility of Burkholderia glumae through Regulation of Rhamnolipids. PLoS One 2015; 10:e0128509. [PMID: 26047513 PMCID: PMC4457897 DOI: 10.1371/journal.pone.0128509] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 04/29/2015] [Indexed: 11/18/2022] Open
Abstract
Burkholderia glumae is a plant pathogenic bacterium that uses an acyl-homoserine lactone-mediated quorum sensing system to regulate protein secretion, oxalate production and major virulence determinants such as toxoflavin and flagella. B. glumae also releases surface-active rhamnolipids. In Pseudomonas aeruginosa and Burkholderia thailandensis, rhamnolipids, along with flagella, are required for the social behavior called swarming motility. In the present study, we demonstrate that quorum sensing positively regulates the production of rhamnolipids in B. glumae and that rhamnolipids are necessary for swarming motility also in this species. We show that a rhlA- mutant, which is unable to produce rhamnolipids, loses its ability to swarm, and that this can be complemented by providing exogenous rhamnolipids. Impaired rhamnolipid production in a quorum sensing-deficient B. glumae mutant is the main factor responsible for its defective swarming motility behaviour.
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Affiliation(s)
- Arvin Nickzad
- INRS—Institut Armand-Frappier, Laval, Québec, Canada
| | | | - Eric Déziel
- INRS—Institut Armand-Frappier, Laval, Québec, Canada
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