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Li K, Ma C, Xiong C, Zhou X, Mao Y, Wang Y, Liu F. Unveiling the Role of Diffusible Signal Factor-Family Quorum Sensing Signals in Regulating Behavior of Xanthomonas and Lysobacter. Phytopathology 2024; 114:512-520. [PMID: 37698468 DOI: 10.1094/phyto-07-23-0264-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/13/2023]
Abstract
Diffusible signal factor (DSF) family signals represent a unique group of quorum sensing (QS) chemicals that modulate a wide range of behaviors for bacteria to adapt to different environments. However, whether DSF-mediated QS signaling acts as a public language to regulate the behavior of biocontrol and pathogenic bacteria remains unknown. In this study, we present groundbreaking evidence demonstrating that RpfFXc1 or RpfFOH11 could be a conserved DSF-family signal synthase in Xanthomonas campestris or Lysobacter enzymogenes. Interestingly, we found that both RpfFOH11 and RpfFXc1 have the ability to synthesize DSF and BDSF signaling molecules. DSF and BDSF positively regulate the biosynthesis of an antifungal factor (heat-stable antifungal factor, HSAF) in L. enzymogenes. Finally, we show that RpfFXc1 and RpfFOH11 have similar functions in regulating HSAF production in L. enzymogenes, as well as the virulence, synthesis of virulence factors, biofilm formation, and extracellular polysaccharide production in X. campestris. These findings reveal a previously uncharacterized mechanism of DSF-mediated regulation in both biocontrol and pathogenic bacteria.
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Affiliation(s)
- Kaihuai Li
- Department of Plant Pathology, College of Agriculture, Guizhou University, Guiyang 550025, China
- Key Laboratory of Agricultural Microbiology, College of Agriculture, Guizhou University, Guiyang 550025, China
- Institute of Vegetable Industry Technology Research, Guizhou University, Guiyang 550025, China
| | - Chaoyun Ma
- Department of Plant Pathology, College of Agriculture, Guizhou University, Guiyang 550025, China
- Key Laboratory of Agricultural Microbiology, College of Agriculture, Guizhou University, Guiyang 550025, China
| | - Chunlan Xiong
- Department of Plant Pathology, College of Agriculture, Guizhou University, Guiyang 550025, China
- Key Laboratory of Agricultural Microbiology, College of Agriculture, Guizhou University, Guiyang 550025, China
| | - Xue Zhou
- Department of Plant Pathology, College of Agriculture, Guizhou University, Guiyang 550025, China
- Key Laboratory of Agricultural Microbiology, College of Agriculture, Guizhou University, Guiyang 550025, China
| | - Yahui Mao
- Hubei Key Laboratory of Quality Control of Characteristic Fruits and Vegetables/College of Life Science and Technology, Hubei Engineering University, Xiaogan 432000, China
| | - Yong Wang
- Department of Plant Pathology, College of Agriculture, Guizhou University, Guiyang 550025, China
- Key Laboratory of Agricultural Microbiology, College of Agriculture, Guizhou University, Guiyang 550025, China
- Institute of Vegetable Industry Technology Research, Guizhou University, Guiyang 550025, China
| | - Fengquan Liu
- Department of Plant Pathology, College of Agriculture, Guizhou University, Guiyang 550025, China
- Key Laboratory of Agricultural Microbiology, College of Agriculture, Guizhou University, Guiyang 550025, China
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
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Martins PMM, Granato LM, Morgan T, Nalin JL, Takita MA, Alfenas-Zerbini P, de Souza AA. Analysis of CRISPR-Cas loci distribution in Xanthomonas citri and its possible control by the quorum sensing system. FEMS Microbiol Lett 2024; 371:fnae005. [PMID: 38244227 DOI: 10.1093/femsle/fnae005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 10/04/2023] [Accepted: 01/18/2024] [Indexed: 01/22/2024] Open
Abstract
Xanthomonas is an important genus of plant-associated bacteria that causes significant yield losses of economically important crops worldwide. Different approaches have assessed genetic diversity and evolutionary interrelationships among the Xanthomonas species. However, information from clustered regularly interspaced short palindromic repeats (CRISPRs) has yet to be explored. In this work, we analyzed the architecture of CRISPR-Cas loci and presented a sequence similarity-based clustering of conserved Cas proteins in different species of Xanthomonas. Although absent in many investigated genomes, Xanthomonas harbors subtype I-C and I-F CRISPR-Cas systems. The most represented species, Xanthomonas citri, presents a great diversity of genome sequences with an uneven distribution of the CRISPR-Cas systems among the subspecies/pathovars. Only X. citri subsp. citri and X. citri pv. punicae have these systems, exclusively of subtype I-C system. Moreover, the most likely targets of the X. citri CRISPR spacers are viruses (phages). At the same time, few are plasmids, indicating that CRISPR/Cas system is possibly a mechanism to control the invasion of foreign DNA. We also showed in X. citri susbp. citri that the cas genes are regulated by the diffusible signal factor, the quorum sensing (QS) signal molecule, according to cell density increases, and under environmental stress like starvation. These results suggest that the regulation of CRISPR-Cas by QS occurs to activate the gene expression only during phage infection or due to environmental stresses, avoiding a possible reduction in fitness. Although more studies are needed, CRISPR-Cas systems may have been selected in the Xanthomonas genus throughout evolution, according to the cost-benefit of protecting against biological threats and fitness maintenance in challenging conditions.
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Affiliation(s)
| | - Laís Moreira Granato
- Citrus Research Center "Sylvio Moreira", Agronomic Institute (IAC), Cordeiropolis-SP 13490-970, Brazil
| | - Túlio Morgan
- Department of Microbiology, Institute of Biotechnology Applied to Agriculture (BIOAGRO), Federal University of Viçosa, Viçosa-MG 36570-900, Brazil
| | - Julia Lopes Nalin
- Citrus Research Center "Sylvio Moreira", Agronomic Institute (IAC), Cordeiropolis-SP 13490-970, Brazil
| | - Marco Aurélio Takita
- Citrus Research Center "Sylvio Moreira", Agronomic Institute (IAC), Cordeiropolis-SP 13490-970, Brazil
| | - Poliane Alfenas-Zerbini
- Department of Microbiology, Institute of Biotechnology Applied to Agriculture (BIOAGRO), Federal University of Viçosa, Viçosa-MG 36570-900, Brazil
| | - Alessandra Alves de Souza
- Citrus Research Center "Sylvio Moreira", Agronomic Institute (IAC), Cordeiropolis-SP 13490-970, Brazil
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Guillén-Navarro D, González-Vázquez R, León-Ávila G, Giono-Cerezo S. Quorum Quenching with a Diffusible Signal Factor Analog in Stenotrophomonas maltophilia. Pathogens 2023; 12:1448. [PMID: 38133331 PMCID: PMC10746098 DOI: 10.3390/pathogens12121448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 12/04/2023] [Accepted: 12/06/2023] [Indexed: 12/23/2023] Open
Abstract
Stenotrophomonas maltophilia is a multidrug-resistant Gram-negative bacillus associated with nosocomial infections in intensive care units, and nowadays, its acquired resistance to trimethoprim-sulfamethoxazole (SXT) by sul genes within class 1 integrons is a worldwide health problem. Biofilm and motility are two of the major virulence factors in this bacterium and are auto-induced by the diffusible signal factor (DSF). In recent studies, retinoids have been used to inhibit (Quorum Quenching) these virulence factors and for their antimicrobial effect. The aim was to reduce biofilm formation and motility with retinoic acid (RA) in S. maltophilia SXT-resistant strains. Eleven SXT-resistant strains and two SXT-susceptible strains were tested for biofilm formation/reduction and planktonic/sessile cell viability with RA and SXT-MIC50/RA; motility (twitching, swimming, swarming) was measured with/without RA; and MLST typing was determined. The biofilm formation of the strains was classified as follows: 15.38% (2/13) as low, 61.54% (8/13) as moderate, and 23.08% (3/13) as high. It was significantly reduced with RA and SXT-MIC50/RA (p < 0.05); cell viability was not significantly reduced with RA (p > 0.05), but it was with SXT-MIC50/RA (p < 0.05); and swimming (p < 0.05) and swarming (p < 0.05) decreased significantly. MLST typing showed the first and novel strains of Mexican S. maltophilia registered in PubMLST (ST479-485, ST497, ST23, ST122, ST175, ST212, and ST300). In conclusion, RA reduced biofilm formation and motility without affecting cell viability; furthermore, antimicrobial synergism with SXT-MIC50/RA in different and novel STs of S. maltophilia was observed.
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Affiliation(s)
- Dafne Guillén-Navarro
- Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Departamento de Microbiología, Prolongación de Carpio y Plan de Ayala S/N, Col. Casco de Santo Tomás, Alcaldía Miguel Hidalgo, Mexico City 11340, Mexico
- Posgrado en Ciencias Quimicobiológicas, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prolongación de Carpio y Plan de Ayala S/N, Col. Casco de Santo Tomás, Alcaldía Miguel Hidalgo, Mexico City 11340, Mexico
| | - Rosa González-Vázquez
- Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Departamento de Microbiología, Prolongación de Carpio y Plan de Ayala S/N, Col. Casco de Santo Tomás, Alcaldía Miguel Hidalgo, Mexico City 11340, Mexico
- Instituto Mexicano del Seguro Social, Unidad Médica de Alta Especialidad, Hospital de Especialidades “Dr. Antonio Fraga Mouret”, Centro Médico Nacional La Raza. Seris y Zaachila S/N, Col. La Raza, Alcaldía Azcapotzalco, Mexico City 04960, Mexico
| | - Gloria León-Ávila
- Posgrado en Ciencias Quimicobiológicas, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prolongación de Carpio y Plan de Ayala S/N, Col. Casco de Santo Tomás, Alcaldía Miguel Hidalgo, Mexico City 11340, Mexico
- Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Departamento de Zoología, Prolongación de Carpio y Plan de Ayala S/N, Col. Casco de Santo Tomás, Alcaldía Miguel Hidalgo, Mexico City 11340, Mexico
| | - Silvia Giono-Cerezo
- Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Departamento de Microbiología, Prolongación de Carpio y Plan de Ayala S/N, Col. Casco de Santo Tomás, Alcaldía Miguel Hidalgo, Mexico City 11340, Mexico
- Posgrado en Ciencias Quimicobiológicas, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prolongación de Carpio y Plan de Ayala S/N, Col. Casco de Santo Tomás, Alcaldía Miguel Hidalgo, Mexico City 11340, Mexico
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Zhu X, Chen WJ, Bhatt K, Zhou Z, Huang Y, Zhang LH, Chen S, Wang J. Innovative microbial disease biocontrol strategies mediated by quorum quenching and their multifaceted applications: A review. Front Plant Sci 2023; 13:1063393. [PMID: 36714722 PMCID: PMC9878147 DOI: 10.3389/fpls.2022.1063393] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 12/15/2022] [Indexed: 06/12/2023]
Abstract
With the increasing resistance exhibited by undesirable bacteria to traditional antibiotics, the need to discover alternative (or, at least, supplementary) treatments to combat chemically resistant bacteria is becoming urgent. Quorum sensing (QS) refers to a novel bacterial communication system for monitoring cell density and regulation of a network of gene expression that is mediated by a group of signaling molecules called autoinducers (AIs). QS-regulated multicellular behaviors include biofilm formation, horizontal gene transfer, and antibiotic synthesis, which are demonstrating increasing pathogenicity to plants and aquacultural animals as well as contamination of wastewater treatment devices. To inhibit QS-regulated microbial behaviors, the strategy of quorum quenching (QQ) has been developed. Different quorum quenchers interfere with QS through different mechanisms, such as competitively inhibiting AI perception (e.g., by QS inhibitors) and AI degradation (e.g., by QQ enzymes). In this review, we first introduce different signaling molecules, including diffusible signal factor (DSF) and acyl homoserine lactones (AHLs) for Gram-negative bacteria, AIPs for Gram-positive bacteria, and AI-2 for interspecies communication, thus demonstrating the mode of action of the QS system. We next exemplify the QQ mechanisms of various quorum quenchers, such as chemical QS inhibitors, and the physical/enzymatic degradation of QS signals. We devote special attention to AHL-degrading enzymes, which are categorized in detail according to their diverse catalytic mechanisms and enzymatic properties. In the final part, the applications and advantages of quorum quenchers (especially QQ enzymes and bacteria) are summarized in the context of agricultural/aquacultural pathogen biocontrol, membrane bioreactors for wastewater treatment, and the attenuation of human pathogenic bacteria. Taken together, we present the state-of-the-art in research considering QS and QQ, providing theoretical evidence and support for wider application of this promising environmentally friendly biocontrol strategy.
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Affiliation(s)
- Xixian Zhu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Plant Protection, South China Agricultural University, Guangzhou, China
| | - Wen-Juan Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Plant Protection, South China Agricultural University, Guangzhou, China
| | - Kalpana Bhatt
- Department of Food Science, Purdue University, West Lafayette, IN, United States
| | - Zhe Zhou
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Plant Protection, South China Agricultural University, Guangzhou, China
| | - Yaohua Huang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Plant Protection, South China Agricultural University, Guangzhou, China
| | - Lian-Hui Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Plant Protection, South China Agricultural University, Guangzhou, China
| | - Shaohua Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Plant Protection, South China Agricultural University, Guangzhou, China
| | - Junxia Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
- Guangdong Laboratory for Lingnan Modern Agriculture, College of Plant Protection, South China Agricultural University, Guangzhou, China
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Rather MA, Chowdhury R, Pavinski Bitar PD, Altier C. Recombinant production of a diffusible signal factor inhibits Salmonella invasion and animal carriage. Gut Microbes 2023; 15:2208498. [PMID: 37158497 PMCID: PMC10171134 DOI: 10.1080/19490976.2023.2208498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 04/21/2023] [Indexed: 05/10/2023] Open
Abstract
The complex chemical environment of the intestine is defined largely by the metabolic products of the resident microbiota. Enteric pathogens, elegantly evolved to thrive in the gut, use these chemical products as signals to recognize specific niches and to promote their survival and virulence. Our previous work has shown that a specific class of quorum-sensing molecules found within the gut, termed diffusible signal factors (DSF), signals the repression of Salmonella tissue invasion, thus defining a means by which this pathogen recognizes its location and modulates virulence to optimize its survival. Here, we determined whether the recombinant production of a DSF could reduce Salmonella virulence in vitro and in vivo. We found that the most potent repressor of Salmonella invasion, cis-2-hexadecenoic acid (c2-HDA), could be recombinantly produced in E. coli by the addition of a single exogenous gene encoding a fatty acid enoyl-CoA dehydratase/thioesterase and that co-culture of the recombinant strain with Salmonella potently inhibited tissue invasion by repressing Salmonella genes required for this essential virulence function. Using the well characterized E. coli Nissle 1917 strain and a chicken infection model, we found that the recombinant DSF-producing strain could be stably maintained in the large intestine. Further, challenge studies demonstrated that this recombinant organism could significantly reduce Salmonella colonization of the cecum, the site of carriage in this animal species. These findings thus describe a plausible means by which Salmonella virulence may be affected in animals by in situ chemical manipulation of functions essential for colonization and virulence.
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Affiliation(s)
- Mudasir Ali Rather
- Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, NY, USA
| | - Rimi Chowdhury
- Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, NY, USA
| | | | - Craig Altier
- Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, NY, USA
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Xu X, Ye T, Zhang W, Zhou T, Zhou X, Dai W, Chen S. Identification of FadT as a Novel Quorum Quenching Enzyme for the Degradation of Diffusible Signal Factor in Cupriavidus pinatubonensis Strain HN-2. Int J Mol Sci 2021; 22:9862. [PMID: 34576026 DOI: 10.3390/ijms22189862] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 09/01/2021] [Accepted: 09/06/2021] [Indexed: 01/01/2023] Open
Abstract
Quorum sensing (QS) is a microbial cell–cell communication mechanism and plays an important role in bacterial infections. QS-mediated bacterial infections can be blocked through quorum quenching (QQ), which hampers signal accumulation, recognition, and communication. The pathogenicity of numerous bacteria, including Xanthomonas campestris pv. campestris (Xcc), is regulated by diffusible signal factor (DSF), a well-known fatty acid signaling molecule of QS. Cupriavidus pinatubonensis HN-2 could substantially attenuate the infection of XCC through QQ by degrading DSF. The QQ mechanism in strain HN-2, on the other hand, is yet to be known. To understand the molecular mechanism of QQ in strain HN-2, we used whole-genome sequencing and comparative genomics studies. We discovered that the fadT gene encodes acyl-CoA dehydrogenase as a novel QQ enzyme. The results of site-directed mutagenesis demonstrated the requirement of fadT gene for DSF degradation in strain HN-2. Purified FadT exhibited high enzymatic activity and outstanding stability over a broad pH and temperature range with maximal activity at pH 7.0 and 35 °C. No cofactors were required for FadT enzyme activity. The enzyme showed a strong ability to degrade DSF. Furthermore, the expression of fadT in Xcc results in a significant reduction in the pathogenicity in host plants, such as Chinese cabbage, radish, and pakchoi. Taken together, our results identified a novel DSF-degrading enzyme, FadT, in C. pinatubonensis HN-2, which suggests its potential use in the biological control of DSF-mediated pathogens.
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Ma Z, Liu X, Nath S, Sun H, Tran TM, Yang L, Mayor S, Miao Y. Formin nanoclustering-mediated actin assembly during plant flagellin and DSF signaling. Cell Rep 2021; 34:108884. [PMID: 33789103 DOI: 10.1016/j.celrep.2021.108884] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 01/11/2021] [Accepted: 02/25/2021] [Indexed: 12/19/2022] Open
Abstract
Plants respond to bacterial infection acutely with actin remodeling during plant immune responses. The mechanisms by which bacterial virulence factors (VFs) modulate plant actin polymerization remain enigmatic. Here, we show that plant-type-I formin serves as the molecular sensor for actin remodeling in response to two bacterial VFs: Xanthomonas campestris pv. campestris (Xcc) diffusible signal factor (DSF), and pathogen-associated molecular pattern (PAMP) flagellin in pattern-triggered immunity (PTI). Both VFs regulate actin assembly by tuning the clustering and nucleation activity of formin on the plasma membrane (PM) at the nano-sized scale. By being integrated within the cell-wall-PM-actin cytoskeleton (CW-PM-AC) continuum, the dynamic behavior and function of formins are highly dependent on each scaffold layer's composition within the CW-PM-AC continuum during both DSF and PTI signaling. Our results reveal a central mechanism for rapid actin remodeling during plant-bacteria interactions, in which bacterial signaling molecules fine tune plant formin nanoclustering in a host mechanical-structure-dependent manner.
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Affiliation(s)
- Zhiming Ma
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Xiaolin Liu
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Sangeeta Nath
- Institute for Stem Cell Biology and Regenerative Medicine, Bellary Road, Bangalore 560065, India; Manipal Institute of Regenerative Medicine, Manipal Academy of Higher Education, Bangalore 560065, India
| | - He Sun
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Tuan Minh Tran
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Liang Yang
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore; Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 637551, Singapore; School of Medicine, Southern University of Science and Technology, 1088 Xueyuan Blvd., Nanshan District, Shenzhen 518055, China
| | - Satyajit Mayor
- Institute for Stem Cell Biology and Regenerative Medicine, Bellary Road, Bangalore 560065, India; National Centre for Biological Sciences, Tata Institute for Fundamental Research, Bellary Road, Bangalore 560065, India
| | - Yansong Miao
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore.
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Baltenneck J, Reverchon S, Hommais F. Quorum Sensing Regulation in Phytopathogenic Bacteria. Microorganisms 2021; 9:239. [PMID: 33498890 DOI: 10.3390/microorganisms9020239] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 01/19/2021] [Accepted: 01/20/2021] [Indexed: 11/17/2022] Open
Abstract
Quorum sensing is a type of chemical communication by which bacterial populations control expression of their genes in a coordinated manner. This regulatory mechanism is commonly used by pathogens to control the expression of genes encoding virulence factors and that of genes involved in the bacterial adaptation to variations in environmental conditions. In phytopathogenic bacteria, several mechanisms of quorum sensing have been characterized. In this review, we describe the different quorum sensing systems present in phytopathogenic bacteria, such as those using the signal molecules named N-acyl-homoserine lactone (AHL), diffusible signal factor (DSF), and the unknown signal molecule of the virulence factor modulating (VFM) system. We focus on studies performed on phytopathogenic bacteria of major importance, including Pseudomonas, Ralstonia, Agrobacterium, Xanthomonas, Erwinia, Xylella,Dickeya, and Pectobacterium spp. For each system, we present the mechanism of regulation, the functions targeted by the quorum sensing system, and the mechanisms by which quorum sensing is regulated.
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Kim HS, Cha E, Ham SY, Park JH, Nam S, Kwon H, Byun Y, Park HD. Linoleic acid inhibits Pseudomonas aeruginosa biofilm formation by activating diffusible signal factor-mediated quorum sensing. Biotechnol Bioeng 2020; 118:82-93. [PMID: 32880907 DOI: 10.1002/bit.27552] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 08/09/2020] [Accepted: 08/29/2020] [Indexed: 12/24/2022]
Abstract
Bacterial biofilm formation causes serious problems in various fields of medical, clinical, and industrial settings. Antibiotics and biocide treatments are typical methods used to remove bacterial biofilms, but biofilms are difficult to remove effectively from surfaces due to their increased resistance. An alternative approach to treatment with antimicrobial agents is using biofilm inhibitors that regulate biofilm development without inhibiting bacterial growth. In the present study, we found that linoleic acid (LA), a plant unsaturated fatty acid, inhibits biofilm formation under static and continuous conditions without inhibiting the growth of Pseudomonas aeruginosa. LA also influenced the bacterial motility, extracellular polymeric substance production, and biofilm dispersion by decreasing the intracellular cyclic diguanylate concentration through increased phosphodiesterase activity. Furthermore, quantitative gene expression analysis demonstrated that LA induced the expression of genes associated with diffusible signaling factor-mediated quorum sensing that can inhibit or induce the dispersion of P. aeruginosa biofilms. These results suggest that LA is functionally and structurally similar to a P. aeruginosa diffusible signaling factor (cis-2-decenoic acid) and, in turn, act as an agonist molecule in biofilm dispersion.
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Affiliation(s)
- Han-Shin Kim
- Korean Peninsula Infrastructure Special Committee, Korea Institute of Civil Engineering and Building Technology, Goyang, South Korea
| | - Eunji Cha
- School of Civil, Environmental and Architectural Engineering, Korea University, Seoul, South Korea
| | - So-Young Ham
- School of Civil, Environmental and Architectural Engineering, Korea University, Seoul, South Korea
| | - Jeong-Hoon Park
- Clean Innovation Technology Group, Korea Institute of Industrial Technology, Jeju, South Korea
| | - SangJin Nam
- College of Pharmacy, Korea University, Sejong, South Korea
| | - Hongmok Kwon
- College of Pharmacy, Korea University, Sejong, South Korea
| | - Youngjoo Byun
- College of Pharmacy, Korea University, Sejong, South Korea.,Biomedical Research Center, Korea University Guro Hospital, Seoul, South Korea
| | - Hee-Deung Park
- School of Civil, Environmental and Architectural Engineering, Korea University, Seoul, South Korea.,KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, South Korea
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Ye T, Zhou T, Xu X, Zhang W, Fan X, Mishra S, Zhang L, Zhou X, Chen S. Whole-Genome Sequencing Analysis of Quorum Quenching Bacterial Strain Acinetobacter lactucae QL-1 Identifies the FadY Enzyme for Degradation of the Diffusible Signal Factor. Int J Mol Sci 2020; 21:E6729. [PMID: 32937869 DOI: 10.3390/ijms21186729] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/08/2020] [Accepted: 09/10/2020] [Indexed: 01/01/2023] Open
Abstract
The diffusible signal factor (DSF) is a fatty acid signal molecule and is widely conserved in various Gram-negative bacteria. DSF is involved in the regulation of pathogenic virulence in many bacterial pathogens, including Xanthomonas campestris pv. campestris (Xcc). Quorum quenching (QQ) is a potential approach for preventing and controlling DSF-mediated bacterial infections by the degradation of the DSF signal. Acinetobacter lactucae strain QL-1 possesses a superb DSF degradation ability and effectively attenuates Xcc virulence through QQ. However, the QQ mechanisms in strain QL-1 are still unknown. In the present study, whole-genome sequencing and comparative genomics analysis were conducted to identify the molecular mechanisms of QQ in strain QL-1. We found that the fadY gene of QL-1 is an ortholog of XccrpfB, a known DSF degradation gene, suggesting that strain QL-1 is capable of inactivating DSF by QQ enzymes. The results of site-directed mutagenesis indicated that fadY is required for strain QL-1 to degrade DSF. The determination of FadY activity in vitro revealed that the fatty acyl-CoA synthetase FadY had remarkable catalytic activity. Furthermore, the expression of fadY in transformed Xcc strain XC1 was investigated and shown to significantly attenuate bacterial pathogenicity on host plants, such as Chinese cabbage and radish. This is the first report demonstrating a DSF degradation enzyme from A. lactucae. Taken together, these findings shed light on the QQ mechanisms of A. lactucae strain QL-1, and provide useful enzymes and related genes for the biocontrol of infectious diseases caused by DSF-dependent bacterial pathogens.
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11
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Koduru L, Kim HY, Lakshmanan M, Mohanty B, Lee YQ, Lee CH, Lee D. Genome-scale metabolic reconstruction and in silico analysis of the rice leaf blight pathogen, Xanthomonas oryzae. Mol Plant Pathol 2020; 21:527-540. [PMID: 32068953 PMCID: PMC7060145 DOI: 10.1111/mpp.12914] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 12/09/2019] [Accepted: 01/13/2020] [Indexed: 05/29/2023]
Abstract
Xanthomonas oryzae pv. oryzae (Xoo) is a vascular pathogen that causes leaf blight in rice, leading to severe yield losses. Since the usage of chemical control methods has not been very promising for the future disease management, it is of high importance to systematically gain new insights about Xoo virulence and pathogenesis, and devise effective strategies to combat the rice disease. To do this, we reconstructed a genome-scale metabolic model of Xoo (iXOO673) and validated the model predictions using culture experiments. Comparison of the metabolic architecture of Xoo and other plant pathogens indicated that the Entner-Doudoroff pathway is a more common feature in these bacteria than previously thought, while suggesting some of the unique virulence mechanisms related to Xoo metabolism. Subsequent constraint-based flux analysis allowed us to show that Xoo modulates fluxes through gluconeogenesis, glycogen biosynthesis, and degradation pathways, thereby exacerbating the leaf blight in rice exposed to nitrogenous fertilizers, which is remarkably consistent with published experimental literature. Moreover, model-based interrogation of transcriptomic data revealed the metabolic components under the diffusible signal factor regulon that are crucial for virulence and survival in Xoo. Finally, we identified promising antibacterial targets for the control of leaf blight in rice by using gene essentiality analysis.
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Affiliation(s)
- Lokanand Koduru
- Bioprocessing Technology InstituteAgency for Science, Technology and ResearchSingapore
| | - Hyang Yeon Kim
- Department of Bioscience and BiotechnologyKonkuk UniversitySeoulRepublic of Korea
| | - Meiyappan Lakshmanan
- Bioprocessing Technology InstituteAgency for Science, Technology and ResearchSingapore
| | - Bijayalaxmi Mohanty
- Bioprocessing Technology InstituteAgency for Science, Technology and ResearchSingapore
| | - Yi Qing Lee
- School of Chemical EngineeringSungkyunkwan UniversitySuwonRepublic of Korea
| | - Choong Hwan Lee
- Department of Bioscience and BiotechnologyKonkuk UniversitySeoulRepublic of Korea
| | - Dong‐Yup Lee
- Bioprocessing Technology InstituteAgency for Science, Technology and ResearchSingapore
- School of Chemical EngineeringSungkyunkwan UniversitySuwonRepublic of Korea
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12
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Ye T, Zhou T, Li Q, Xu X, Fan X, Zhang L, Chen S. Cupriavidus sp. HN-2, a Novel Quorum Quenching Bacterial Isolate, is a Potent Biocontrol Agent Against Xanthomonas campestris pv. campestris. Microorganisms 2019; 8:E45. [PMID: 31881662 DOI: 10.3390/microorganisms8010045] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 12/21/2019] [Accepted: 12/22/2019] [Indexed: 11/17/2022] Open
Abstract
Diffusible signal factor (DSF) represents a family of widely conserved quorum sensing (QS) signals involved in the regulation of virulence factor production in many Gram-negative bacterial pathogens. Quorum quenching, which disrupts QS either by degradation of QS signals or interference of signal generation or perception, is a promising strategy for prevention and control of QS-mediated bacterial infections. In this study, a novel DSF-degrading strain, HN-2, was isolated from contaminated soil and identified as Cupriavidus sp. The isolate exhibited superior DSF degradation activity and completely degraded 2 mmol·L–1 of DSF within 24 h. Analysis of the degradation products of DSF by gas chromatography–mass spectrometry led to the identification of trans-2-decenoic acid methyl ester as the main intermediate product, suggesting that DSF could be degraded by oxidation and hydroxylation. Moreover, this study presents for the first time, evidence that Cupriavidus sp. can reduce the black rot disease caused by Xanthomonas campestris pv. campestris (Xcc). Application of the HN-2 strain as a biocontrol agent could substantially reduce the disease severity. These findings reveal the biochemical basis of a highly efficient DSF-degrading bacterial isolate and present a useful agent for controlling infectious diseases caused by DSF-dependent bacterial pathogens.
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13
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Ye T, Zhou T, Fan X, Bhatt P, Zhang L, Chen S. Acinetobacter lactucae Strain QL-1, a Novel Quorum Quenching Candidate Against Bacterial Pathogen Xanthomonas campestris pv. campestris. Front Microbiol 2019; 10:2867. [PMID: 31921047 PMCID: PMC6929412 DOI: 10.3389/fmicb.2019.02867] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Accepted: 11/27/2019] [Indexed: 11/16/2022] Open
Abstract
Quorum sensing (QS) is a cell–cell communication mechanism among bacterial populations that is regulated through gene expression in response to cell density. The pathogenicity of Xanthomonas campestris pv. campestris (Xcc) is modulated by the diffusible signal factor (DSF)-mediated QS system. DSF is widely conserved in a variety of gram-negative bacterial pathogens. In this study, DSF-degrading bacteria and their enzymes were thoroughly explored as a biocontrol agent against Xcc. The results indicated that a novel DSF-degrading bacterium, Acinetobacter lactucae QL-1, effectively attenuated Xcc virulence through quorum quenching. Lab-based experiments indicated that plants inoculated with QL-1 and Xcc had less tissue decay than those inoculated with Xcc alone. Co-inoculation of strains Xcc and QL-1 significantly reduced the incidence and severity of disease in plants. Similarly, the application of crude enzymes of strain QL-1 substantially reduced the disease severity caused by Xcc. The results showed that strain QL-1 and its enzymes possess promising potential, which could be further investigated to better protect plants from DSF-dependent pathogens.
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Affiliation(s)
- Tian Ye
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Laboratory of Lingnan Modern Agricultural Science and Technology, South China Agricultural University, Guangzhou, China
| | - Tian Zhou
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Laboratory of Lingnan Modern Agricultural Science and Technology, South China Agricultural University, Guangzhou, China
| | - Xinghui Fan
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Laboratory of Lingnan Modern Agricultural Science and Technology, South China Agricultural University, Guangzhou, China
| | - Pankaj Bhatt
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Laboratory of Lingnan Modern Agricultural Science and Technology, South China Agricultural University, Guangzhou, China
| | - Lianhui Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Laboratory of Lingnan Modern Agricultural Science and Technology, South China Agricultural University, Guangzhou, China
| | - Shaohua Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Laboratory of Lingnan Modern Agricultural Science and Technology, South China Agricultural University, Guangzhou, China
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14
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Homa M, Sándor A, Tóth E, Szebenyi C, Nagy G, Vágvölgyi C, Papp T. In vitro Interactions of Pseudomonas aeruginosa With Scedosporium Species Frequently Associated With Cystic Fibrosis. Front Microbiol 2019; 10:441. [PMID: 30894846 PMCID: PMC6414507 DOI: 10.3389/fmicb.2019.00441] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Accepted: 02/20/2019] [Indexed: 11/13/2022] Open
Abstract
Members of the Scedosporium apiospermum species complex are the second most frequently isolated pathogens after Aspergillus fumigatus from cystic fibrosis (CF) patients with fungal pulmonary infections. Even so, the main risk factors for the infection are unrevealed. According to previous studies, bacterial infections might reduce the risk of a fungal infection, but an antibacterial therapy may contribute to the airway colonization by several fungal pathogens. Furthermore, corticosteroids, which are often used to reduce lung inflammation in children and adults with CF, are also proved to enhance the growth of A. fumigatus in vitro. Considering all the above discussed points, we aimed to test how Pseudomonas aeruginosa influences the growth of scedosporia and to investigate the potential effect of commonly applied antibacterial agents and corticosteroids on Scedosporium species. Direct interactions between fungal and bacterial strains were tested using the disk inhibition method. Indirect interactions via volatile compounds were investigated by the plate-in-plate method, while the effect of bacterial media-soluble molecules was tested using a modified cellophane assay and also in liquid culture media conditioned by P. aeruginosa. To test the effect of bacterial signal molecules, antibacterial agents and corticosteroids on the fungal growth, the broth microdilution method was used. We also investigated the germination ability of Scedosporium conidia in the presence of pyocyanin and diffusible signal factor by microscopy. According to our results, P. aeruginosa either inhibited or enhanced the growth of scedosporia depending on the culture conditions and the mode of interactions. When the two pathogens were cultured physically separately from each other in the plate-in-plate tests, the presence of the bacteria was able to stimulate the growth of several fungal isolates. While in direct physical contact, bacterial strains inhibited the fungal growth. This effect might be attributed to bacterial signal molecules, which also proved to inhibit the germination and growth of scedosporia. In addition, antibacterial agents showed growth-promoting, while corticosteroids exhibited growth inhibitory effect on several Scedosporium isolates. These data raise the possibility that a P. aeruginosa infection or a previously administered antibacterial therapy might be able to increase the chance of a Scedosporium colonization in a CF lung.
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Affiliation(s)
- Mónika Homa
- MTA-SZTE "Lendület" Fungal Pathogenicity Mechanisms Research Group, Szeged, Hungary.,Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Alexandra Sándor
- MTA-SZTE "Lendület" Fungal Pathogenicity Mechanisms Research Group, Szeged, Hungary.,Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - Eszter Tóth
- MTA-SZTE "Lendület" Fungal Pathogenicity Mechanisms Research Group, Szeged, Hungary.,Interdisciplinary Excellence Centre, Department of Microbiology, University of Szeged, Szeged, Hungary
| | - Csilla Szebenyi
- MTA-SZTE "Lendület" Fungal Pathogenicity Mechanisms Research Group, Szeged, Hungary.,Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary.,Interdisciplinary Excellence Centre, Department of Microbiology, University of Szeged, Szeged, Hungary
| | - Gábor Nagy
- MTA-SZTE "Lendület" Fungal Pathogenicity Mechanisms Research Group, Szeged, Hungary.,Interdisciplinary Excellence Centre, Department of Microbiology, University of Szeged, Szeged, Hungary
| | - Csaba Vágvölgyi
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary.,Interdisciplinary Excellence Centre, Department of Microbiology, University of Szeged, Szeged, Hungary
| | - Tamás Papp
- MTA-SZTE "Lendület" Fungal Pathogenicity Mechanisms Research Group, Szeged, Hungary.,Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary.,Interdisciplinary Excellence Centre, Department of Microbiology, University of Szeged, Szeged, Hungary
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15
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Li KH, Yu YH, Dong HJ, Zhang WB, Ma JC, Wang HH. Biological Functions of ilvC in Branched-Chain Fatty Acid Synthesis and Diffusible Signal Factor Family Production in Xanthomonas campestris. Front Microbiol 2017; 8:2486. [PMID: 29312195 PMCID: PMC5733099 DOI: 10.3389/fmicb.2017.02486] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 11/29/2017] [Indexed: 12/16/2022] Open
Abstract
In bacteria, the metabolism of branched-chain amino acids (BCAAs) is tightly associated with branched-chain fatty acids (BCFAs) synthetic pathways. Although previous studies have reported on BCFAs biosynthesis, more detailed associations between BCAAs metabolism and BCFAs biosynthesis remain to be addressed. In this study, we deleted the ilvC gene, which encodes ketol-acid reductoisomerase in the BCAAs synthetic pathway, from the Xanthomonas campestris pv. campestris (Xcc) genome. We characterized gene functions in BCFAs biosynthesis and production of the diffusible signal factor (DSF) family signals. Disruption of ilvC caused Xcc to become auxotrophic for valine and isoleucine, and lose the ability to synthesize BCFAs via carbohydrate metabolism. Furthermore, ilvC mutant reduced the ability to produce DSF-family signals, especially branched-chain DSF-family signals, which might be the main reason for Xcc reduction of pathogenesis toward host plants. In this report, we confirmed that BCFAs do not have major functions in acclimatizing Xcc cells to low temperatures.
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Affiliation(s)
- Kai-Huai Li
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, China
| | - Yong-Hong Yu
- Guangdong Food and Drug Vocational College, Guangzhou, China
| | - Hui-Juan Dong
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, China
| | - Wen-Bin Zhang
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, China
| | - Jin-Cheng Ma
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, China
| | - Hai-Hong Wang
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, China
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16
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Suppiger A, Schmid N, Aguilar C, Pessi G, Eberl L. Two quorum sensing systems control biofilm formation and virulence in members of the Burkholderia cepacia complex. Virulence 2014; 4:400-9. [PMID: 23799665 PMCID: PMC3714132 DOI: 10.4161/viru.25338] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The Burkholderia cepacia complex (Bcc) consists of 17 closely related species that are problematic opportunistic bacterial pathogens for cystic fibrosis patients and immunocompromised individuals. These bacteria are capable of utilizing two different chemical languages: N-acyl homoserine lactones (AHLs) and cis-2-unsaturated fatty acids. Here we summarize the current knowledge of the underlying molecular architectures of these communication systems, showing how they are interlinked and discussing how they regulate overlapping as well as specific sets of genes. A particular focus is laid on the role of these signaling systems in the formation of biofilms, which are believed to be highly important for chronic infections. We review genes that have been implicated in the sessile lifestyle of this group of bacteria. The new emerging role of the intracellular second messenger cyclic dimeric guanosine monophosphate (c-di-GMP) as a downstream regulator of the fatty acid signaling cascade and as a key factor in biofilm formation is also discussed.
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Affiliation(s)
- Angela Suppiger
- Department of Microbiology, University of Zürich, Zürich, Switzerland
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17
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Cho JH, Yoon JM, Lee SW, Noh YH, Cha JS. Xanthomonas oryzae pv. oryzae RpfE Regulates Virulence and Carbon Source Utilization without Change of the DSF Production. Plant Pathol J 2013; 29:364-373. [PMID: 25288965 PMCID: PMC4174818 DOI: 10.5423/ppj.oa.06.2013.0057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2013] [Revised: 06/09/2013] [Accepted: 06/18/2013] [Indexed: 06/03/2023]
Abstract
It has been known that most regulation of pathogenicity factor (rpf) genes in xanthomonads regulates virulence in response to the diffusible signal factor, DSF. Although many rpf genes have been functionally characterized, the function of rpfE is still unknown. We cloned the rpfE gene from a Xanthomonas oryzae pv. oryzae (Xoo) Korean race KACC10859 and generated mutant strains to elucidate the role of RpfE with respect to the rpf system. Through experiments using the rpfE-deficient mutant strain, we found that mutation in rpfE gene in Xoo reduced virulence, swarm motility, and production of virulence factors such as cellulase and extracellular polysaccharide. Disease progress by the rpfE-deficient mutant strain was significantly slowed compared to disease progress by the wild type and the number of the rpfE-deficient mutant strain was lower than that of the wild type in the early phase of infection in the inoculated rice leaf. The rpfE mutant strain was unable to utilize sucrose or xylose as carbon sources efficiently in culture. The mutation in rpfE, however, did not affect DSF synthesis. Our results suggest that the rpfE gene regulates the virulence of Xoo under different nutrient conditions without change of DSF production.
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Affiliation(s)
- Jung-Hee Cho
- Department of Plant Medicine, Chungbuk National University, Cheongju, Chungbuk 361-763, Korea
| | - Joo-Mi Yoon
- Department of Plant Molecular Systems Biotech & Crop Biotech Institute, KyungHee University, Yongin 446-701, Korea
| | - Sang-Won Lee
- Department of Plant Molecular Systems Biotech & Crop Biotech Institute, KyungHee University, Yongin 446-701, Korea
| | - Young-Hee Noh
- Department of Plant Medicine, Chungbuk National University, Cheongju, Chungbuk 361-763, Korea
| | - Jae-Soon Cha
- Department of Plant Medicine, Chungbuk National University, Cheongju, Chungbuk 361-763, Korea
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