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Ben Moussa H, Pédron J, Hugouvieux-Cotte-Pattat N, Barny MA. Two species with a peculiar evolution within the genus Pectobacterium suggest adaptation to a new environmental niche. Environ Microbiol 2023; 25:2465-2480. [PMID: 37550252 DOI: 10.1111/1462-2920.16479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 07/20/2023] [Indexed: 08/09/2023]
Abstract
Historically, research on Soft Rot Pectobacteriacea (SRP) has focused on economically important crops and ornamentals and knowledge of these bacteria outside the plant context remains poorly investigated. Recently, two closely related species Pectobacterium aquaticum and Pectobacterium quasiaquaticum were isolated from water and have not been isolated from any plant yet. To identify the distinctive characteristics of these two species, we performed a comparative genomic analysis of 80 genomes representing 19 Pectobacterium species and performed an evolutionary reconstruction. Both water species underwent a reduction in genome size associated with a high pseudogene content. A high gene loss was predicted at the emergence of both species. Among the 199 gene families missing from both P. aquaticum and P. quasiaquaticum genomes but present in at least 80% of other Pectobacterium genomes, COG analysis identified many genes involved in nutrient transport systems. In addition, many type II secreted proteins were also missing in both species. Phenotypic analysis revealed that both species had reduced pectinolytic activity, a biofilm formation defect, were highly motile and had reduced virulence on several plants. These genomic and phenotypic data suggest that the ecological niche of P. aquaticum and P. quasiaquaticum may differ from that of other Pectobacterium species.
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Affiliation(s)
- Hajar Ben Moussa
- Sorbonne Université, INRAE, IRD, CNRS, UPEC, UMR 7618 Institut d'Écologie et des Sciences de l'Environnement de Paris, Paris, France
| | - Jacques Pédron
- Sorbonne Université, INRAE, IRD, CNRS, UPEC, UMR 7618 Institut d'Écologie et des Sciences de l'Environnement de Paris, Paris, France
| | | | - Marie-Anne Barny
- Sorbonne Université, INRAE, IRD, CNRS, UPEC, UMR 7618 Institut d'Écologie et des Sciences de l'Environnement de Paris, Paris, France
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Robic K, Munier E, Effantin G, Lachat J, Naquin D, Gueguen E, Faure D. Dissimilar gene repertoires of Dickeya solani involved in the colonization of lesions and roots of Solanum tuberosum. FRONTIERS IN PLANT SCIENCE 2023; 14:1154110. [PMID: 37223796 PMCID: PMC10202176 DOI: 10.3389/fpls.2023.1154110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 04/12/2023] [Indexed: 05/25/2023]
Abstract
Dickeya and Pectobacterium species are necrotrophic pathogens that macerate stems (blackleg disease) and tubers (soft rot disease) of Solanum tuberosum. They proliferate by exploiting plant cell remains. They also colonize roots, even if no symptoms are observed. The genes involved in pre-symptomatic root colonization are poorly understood. Here, transposon-sequencing (Tn-seq) analysis of Dickeya solani living in macerated tissues revealed 126 genes important for competitive colonization of tuber lesions and 207 for stem lesions, including 96 genes common to both conditions. Common genes included acr genes involved in the detoxification of plant defense phytoalexins and kduD, kduI, eda (=kdgA), gudD, garK, garL, and garR genes involved in the assimilation of pectin and galactarate. In root colonization, Tn-seq highlighted 83 genes, all different from those in stem and tuber lesion conditions. They encode the exploitation of organic and mineral nutrients (dpp, ddp, dctA, and pst) including glucuronate (kdgK and yeiQ) and synthesis of metabolites: cellulose (celY and bcs), aryl polyene (ape), and oocydin (ooc). We constructed in-frame deletion mutants of bcsA, ddpA, apeH, and pstA genes. All mutants were virulent in stem infection assays, but they were impaired in the competitive colonization of roots. In addition, the ΔpstA mutant was impaired in its capacity to colonize progeny tubers. Overall, this work distinguished two metabolic networks supporting either an oligotrophic lifestyle on roots or a copiotrophic lifestyle in lesions. This work revealed novel traits and pathways important for understanding how the D. solani pathogen efficiently survives on roots, persists in the environment, and colonizes progeny tubers.
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Affiliation(s)
- Kévin Robic
- French Federation of Seed Potato Growers (FN3PT/inov3PT), Paris, France
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Euphrasie Munier
- French Federation of Seed Potato Growers (FN3PT/inov3PT), Paris, France
| | - Géraldine Effantin
- Univ Lyon, Université Claude Bernard Lyon1, CNRS, INSA Lyon, UMR5240 MAP, Lyon, France
| | - Joy Lachat
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Delphine Naquin
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Erwan Gueguen
- Univ Lyon, Université Claude Bernard Lyon1, CNRS, INSA Lyon, UMR5240 MAP, Lyon, France
| | - Denis Faure
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
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Hossain A, Ali MA, Lin L, Luo J, You Y, Masum MMI, Jiang Y, Wang Y, Li B, An Q. Biocontrol of Soft Rot Dickeya and Pectobacterium Pathogens by Broad-Spectrum Antagonistic Bacteria within Paenibacillus polymyxa Complex. Microorganisms 2023; 11:microorganisms11040817. [PMID: 37110240 PMCID: PMC10142376 DOI: 10.3390/microorganisms11040817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/16/2023] [Accepted: 03/20/2023] [Indexed: 04/29/2023] Open
Abstract
Polymyxin-producing bacteria within the Paenibacillus polymyxa complex have broad-spectrum activities against fungi and bacteria. Their antibacterial activities against soft rot Dickeya and Pectobacterium phytopathogens containing multiple polymyxin-resistant genes were not clear. Here, we selected nine strains within the P. polymyxa complex having broad-spectrum antagonistic activities against phytopathogenic fungi and a polymyxin-resistant D. dadantii strain causing stem and root rot disease of sweet potato and did antagonistic assays on nutrient agar and sweet potato tuber slices. These strains within the P. polymyxa complex showed clear antagonistic activities against D. dadantii in vitro and in vivo. The most effective antagonistic strain P. polymyxa ShX301 showed broad-spectrum antagonistic activities against all the test Dickeya and Pectobacterium strains, completely eliminated D. dadantii from sweet potato seed tubers, and promoted the growth of sweet potato seedlings. Cell-free culture filtrate of P. polymyxa ShX301 inhibited D. dadantii growth, swimming motility, and biofilm formation and disrupted D. dadantii plasma membranes, releasing nucleic acids and proteins. Multiple lipopeptides produced by P. polymyxa ShX301 may play a major role in the bactericidal and bacteriostatic actions. This study clarifies that the antimicrobial spectrum of polymyxin-producing bacteria within the P. polymyxa complex includes the polymyxin-resistant Dickeya and Pectobacterium phytopathogens and strengthens the fact that bacteria within the P. polymyxa complex have high probability of being effective biocontrol agents and plant growth promoters.
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Affiliation(s)
- Afsana Hossain
- State Key Laboratory of Rice Biology and Breeding, Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang Province Key Laboratory of Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
- Department of Plant Pathology, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur 1706, Bangladesh
| | - Md Arshad Ali
- State Key Laboratory of Rice Biology and Breeding, Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang Province Key Laboratory of Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Li Lin
- Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China
| | - Jinyan Luo
- Department of Plant Quarantine, Shanghai Extension and Service Center of Agriculture Technology, Shanghai 201103, China
| | - Yuxin You
- State Key Laboratory of Rice Biology and Breeding, Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang Province Key Laboratory of Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Md Mahidul Islam Masum
- Department of Plant Pathology, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur 1706, Bangladesh
| | - Yugen Jiang
- Agricultural Technology Extension Center of Fuyang District, Hangzhou 311400, China
| | - Yanli Wang
- State Key Laboratory for Quality and Safety of Agro-Products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Bin Li
- State Key Laboratory of Rice Biology and Breeding, Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang Province Key Laboratory of Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Qianli An
- State Key Laboratory of Rice Biology and Breeding, Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang Province Key Laboratory of Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
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Host plant physiological transformation and microbial population heterogeneity as important determinants of the Soft Rot Pectobacteriaceae-plant interactions. Semin Cell Dev Biol 2023; 148-149:33-41. [PMID: 36621443 DOI: 10.1016/j.semcdb.2023.01.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 01/04/2023] [Accepted: 01/04/2023] [Indexed: 01/07/2023]
Abstract
Pectobacterium and Dickeya species belonging to the Soft Rot Pectobacteriaceae (SRP) are one of the most devastating phytopathogens. They degrade plant tissues by producing an arsenal of plant cell wall degrading enzymes. However, SRP-plant interactions are not restricted to the production of these "brute force" weapons. Additionally, these bacteria apply stealth behavior related to (1) manipulation of the host plant via induction of susceptible responses and (2) formation of heterogeneous populations with functionally specialized cells. Our review aims to summarize current knowledge on SRP-induced plant susceptible responses and on the heterogeneity of SRP populations. The review shows that SRP are capable of adjusting the host's hormonal balance, inducing host-mediated plant cell wall modification, promoting iron assimilation by the host, stimulating the accumulation of reactive oxygen species and host cell death, and activating the synthesis of secondary metabolites that are ineffective in limiting disease progression. By this means, SRP facilitate host plant susceptibility. During host colonization, SRP populations produce various functionally specialized cells adapted for enhanced virulence, increased resistance, motility, vegetative growth, or colonization of the vascular system. This enables SRP to perform self-contradictory tasks, which benefits a population's overall fitness in various environments, including host plants. Such stealthy tactical actions facilitate plant-SRP interactions and disease progression.
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Effects of Rhapontigenin as a Novel Quorum-Sensing Inhibitor on Exoenzymes and Biofilm Formation of Pectobacterium carotovorum subsp. carotovorum and Its Application in Vegetables. Molecules 2022; 27:molecules27248878. [PMID: 36558013 PMCID: PMC9788590 DOI: 10.3390/molecules27248878] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 12/05/2022] [Accepted: 12/06/2022] [Indexed: 12/15/2022] Open
Abstract
The aim of this study was to devise a method to protect Chinese cabbage (Brassica chinensis) and lettuce (Lactuca sativa) from bacterial-disease-induced damage during storage. Thus, the potential of rhapontigenin as a quorum sensing (QS) inhibitor against Pectobacterium carotovorum subsp. carotovorum (P. carotovorum) was evaluated. The QS inhibitory effects of rhapontigenin were confirmed by significant inhibition of the production of violacein in Chromobacterium violaceum CV026 (C. violaceum, CV026). The inhibitory effects of rhapontigenin on the motility, exopolysaccharide (EPS) production, biofilm formation and virulence−exoenzyme synthesis of P. carotovorum were investigated. Acyl-homoserine lactones (AHLs) were quantified using liquid chromatography−mass spectrometry (LC−MS). The inhibitory effects of rhapontigenin on the development of biofilms were observed using fluorescence microscopy and scanning electron microscopy (SEM). A direct-inoculation assay was performed to investigate the QS inhibitory effects of rhapontigenin on P. carotovorum in Chinese cabbage and lettuce. Our results demonstrated that rhapontigenin exhibited significant inhibition (p < 0.05) of the motility, EPS production, biofilm formation, virulence−exoenzyme synthesis and AHL production of P. carotovorum. Additionally, the result of the direct-inoculation assay revealed that rhapontigenin might provide vegetables with significant shelf-life extension and prevent quality loss by controlling the spread of soft-rot symptoms. Consequently, the study provided a significant insight into the potential of rhapontigenin as a QS inhibitor against P. carotovorum.
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Lv M, Ye S, Hu M, Xue Y, Liang Z, Zhou X, Zhang L, Zhou J. Two-component system ArcBA modulates cell motility and biofilm formation in Dickeya oryzae. FRONTIERS IN PLANT SCIENCE 2022; 13:1033192. [PMID: 36340374 PMCID: PMC9634086 DOI: 10.3389/fpls.2022.1033192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 10/11/2022] [Indexed: 06/16/2023]
Abstract
Phytopathogen Dickeya oryzae is a causal agent of rice foot rot disease and the pathogen has an array of virulence factors, such as phytotoxin zeamines, plant cell wall degrading enzymes, cell motility, and biofilms, collectively contributing to the bacterial pathogenesis. In this study, through deletion analysis of predicted regulatory genes in D. oryzae EC1, we identified a two-component system associated with the regulation of bacterial virulence. The two-component system contains a histidine kinase ArcB and a response regulator ArcA, and deletion of their coding genes resulted in changed phenotypes in cell motility, biofilm formation, and bacterial virulence. Electrophoretic mobility shift assay revealed that ArcA bound to the promoters of the bcs operon and bssS, which respectively encode enzymes for the synthesis of celluloses and a biofilm formation regulatory protein. ArcA could also bind to the promoters of three virulence associated transcriptional regulatory genes, i.e., fis, slyA and ohrR. Surprisingly, although these three regulators were shown to modulate the production of cell wall degrading enzymes and zeamines, deletion of arcB and arcA did not seem to affect these phenotypes. Taken together, the findings from this study unveiled a new two-component system associated with the bacterial pathogenesis, which contributes to the virulence of D. oryzae mainly through its action on bacterial motility and biofilm formation.
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Affiliation(s)
- Mingfa Lv
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
| | - Sixuan Ye
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
| | - Ming Hu
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
| | - Yang Xue
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
| | - Zhibin Liang
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
| | - Xiaofan Zhou
- 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, South China Agricultural University, Guangzhou, Guangdong Province, China
| | - Lianhui Zhang
- 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, South China Agricultural University, Guangzhou, Guangdong Province, China
| | - Jianuan Zhou
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou, China
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Lv M, Chen Y, Hu M, Yu Q, Duan C, Ye S, Ling J, Zhou J, Zhou X, Zhang L. OhrR is a central transcriptional regulator of virulence in Dickeya zeae. MOLECULAR PLANT PATHOLOGY 2022; 23:45-59. [PMID: 34693617 PMCID: PMC8659590 DOI: 10.1111/mpp.13141] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 08/20/2021] [Accepted: 09/01/2021] [Indexed: 06/12/2023]
Abstract
Dickeya zeae is the causal agent of rice foot rot disease. The pathogen is known to rely on a range of virulence factors, including phytotoxin zeamines, extracellular enzymes, cell motility, and biofilm, which collectively contribute to the establishment of infections. Phytotoxin zeamines play a critical role in bacterial virulence; signalling pathways and regulatory mechanisms that govern bacterial virulence remain unclear. In this study, we identified a transcriptional regulator OhrR (organic hydroperoxide reductase regulator) that is involved in the regulation of zeamine production in D. zeae EC1. The OhrR null mutant was significantly attenuated in its virulence against rice seed, potato tubers and radish roots. Phenotype analysis showed that OhrR was also involved in the regulation of other virulence traits, including the production of extracellular cellulase, biofilm formation, and swimming/swarming motility. DNA electrophoretic mobility shift assay showed that OhrR directly regulates the transcription of key virulence genes and genes encoding bis-(3'-5')-cyclic dimeric guanosine monophosphate synthetases. Furthermore, OhrR positively regulates the transcription of regulatory genes slyA and fis through binding to their promoter regions. Our findings identify a key regulator of the virulence of D. zeae and add new insights into the complex regulatory network that modulates the physiology and virulence of D. zeae.
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Affiliation(s)
- Mingfa Lv
- Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhouChina
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhouChina
- Guangdong Laboratory for Lingnan Modern AgricultureSouth China Agricultural UniversityGuangzhouChina
| | - Yufan Chen
- Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhouChina
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhouChina
- Guangdong Laboratory for Lingnan Modern AgricultureSouth China Agricultural UniversityGuangzhouChina
| | - Ming Hu
- Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhouChina
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhouChina
- Guangdong Laboratory for Lingnan Modern AgricultureSouth China Agricultural UniversityGuangzhouChina
| | - Qinglin Yu
- Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhouChina
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhouChina
- Guangdong Laboratory for Lingnan Modern AgricultureSouth China Agricultural UniversityGuangzhouChina
| | - Cheng Duan
- Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhouChina
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhouChina
- Guangdong Laboratory for Lingnan Modern AgricultureSouth China Agricultural UniversityGuangzhouChina
| | - Sixuan Ye
- Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhouChina
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhouChina
- Guangdong Laboratory for Lingnan Modern AgricultureSouth China Agricultural UniversityGuangzhouChina
| | - Jinfeng Ling
- Guangdong Provincial Key Laboratory of High Technology for Plant ProtectionResearch Institute of Plant ProtectionGuangdong Academy of Agricultural SciencesGuangzhouChina
| | - Jianuan Zhou
- Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhouChina
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhouChina
- Guangdong Laboratory for Lingnan Modern AgricultureSouth China Agricultural UniversityGuangzhouChina
| | - Xiaofan Zhou
- Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhouChina
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhouChina
- Guangdong Laboratory for Lingnan Modern AgricultureSouth China Agricultural UniversityGuangzhouChina
| | - Lianhui Zhang
- Integrative Microbiology Research CentreSouth China Agricultural UniversityGuangzhouChina
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhouChina
- Guangdong Laboratory for Lingnan Modern AgricultureSouth China Agricultural UniversityGuangzhouChina
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Tague JG, Regmi A, Gregory GJ, Boyd EF. Fis Connects Two Sensory Pathways, Quorum Sensing and Surface Sensing, to Control Motility in Vibrio parahaemolyticus. Front Microbiol 2021; 12:669447. [PMID: 34858358 PMCID: PMC8630636 DOI: 10.3389/fmicb.2021.669447] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 09/22/2021] [Indexed: 01/13/2023] Open
Abstract
Factor for inversion stimulation (Fis) is a global regulator that is highly expressed during exponential phase growth and undetectable in stationary phase growth. Quorum sensing (QS) is a global regulatory mechanism that controls gene expression in response to changes in cell density and growth phase. In Vibrio parahaemolyticus, a marine species and a significant human pathogen, the QS regulatory sRNAs, Qrr1 to Qrr5, are expressed during exponential growth and negatively regulate the high cell density QS master regulator OpaR. OpaR is a positive regulator of capsule polysaccharide (CPS) formation, which is required for biofilm formation, and is a repressor of lateral flagella required for swarming motility. In V. parahaemolyticus, we show that Fis is a positive regulator of the qrr sRNAs expression. In an in-frame fis deletion mutant, qrr expression was repressed and opaR expression was induced. The Δfis mutant produced CPS and biofilm, but swarming motility was abolished. Also, the fis deletion mutant was more sensitive to polymyxin B. Swarming motility requires expression of both the surface sensing scrABC operon and lateral flagella laf operon. Our data showed that in the Δfis mutant both laf and scrABC genes were repressed. Fis controlled swarming motility indirectly through the QS pathway and directly through the surface sensing pathway. To determine the effects of Fis on cellular metabolism, we performed in vitro growth competition assays, and found that Δfis was outcompeted by wild type in minimal media supplemented with intestinal mucus as a sole nutrient source. The data showed that Fis positively modulated mucus components L-arabinose, D-gluconate and N-acetyl-D-glucosamine catabolism gene expression. In an in vivo colonization competition assay, Δfis was outcompeted by wild type, indicating Fis is required for fitness. Overall, these data demonstrate a global regulatory role for Fis in V. parahaemolyticus that includes QS, motility, and metabolism.
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Affiliation(s)
- Jessica G Tague
- Department of Biological Sciences, University of Delaware, Newark, DE, United States
| | - Abish Regmi
- Department of Biological Sciences, University of Delaware, Newark, DE, United States
| | - Gwendolyn J Gregory
- Department of Biological Sciences, University of Delaware, Newark, DE, United States
| | - E Fidelma Boyd
- Department of Biological Sciences, University of Delaware, Newark, DE, United States
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Leonard S, Villard C, Nasser W, Reverchon S, Hommais F. RNA Chaperones Hfq and ProQ Play a Key Role in the Virulence of the Plant Pathogenic Bacterium Dickeya dadantii. Front Microbiol 2021; 12:687484. [PMID: 34248909 PMCID: PMC8264596 DOI: 10.3389/fmicb.2021.687484] [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: 03/29/2021] [Accepted: 05/31/2021] [Indexed: 12/01/2022] Open
Abstract
Dickeya dadantii is an important pathogenic bacterium that infects a number of crops including potato and chicory. While extensive works have been carried out on the control of the transcription of its genes encoding the main virulence functions, little information is available on the post-transcriptional regulation of these functions. We investigated the involvement of the RNA chaperones Hfq and ProQ in the production of the main D. dadantii virulence functions. Phenotypic assays on the hfq and proQ mutants showed that inactivation of hfq resulted in a growth defect, a modified capacity for biofilm formation and strongly reduced motility, and in the production of degradative extracellular enzymes (proteases, cellulase, and pectate lyases). Accordingly, the hfq mutant failed to cause soft rot on chicory leaves. The proQ mutant had reduced resistance to osmotic stress, reduced extracellular pectate lyase activity compared to the wild-type strain, and reduced virulence on chicory leaves. Most of the phenotypes of the hfq and proQ mutants were related to the low amounts of mRNA of the corresponding virulence factors. Complementation of the double mutant hfq-proQ by each individual protein and cross-complementation of each chaperone suggested that they might exert their effects via partially overlapping but different sets of targets. Overall, it clearly appeared that the two Hfq and ProQ RNA chaperones are important regulators of pathogenicity in D. dadantii. This underscores that virulence genes are regulated post-transcriptionally by non-coding RNAs.
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Affiliation(s)
- Simon Leonard
- Université de Lyon, INSA Lyon, Université Claude Bernard Lyon 1, CNRS, UMR 5240 MAP, Microbiologie, Adaptation, Pathogénie, Villeurbanne, France
| | - Camille Villard
- Université de Lyon, INSA Lyon, Université Claude Bernard Lyon 1, CNRS, UMR 5240 MAP, Microbiologie, Adaptation, Pathogénie, Villeurbanne, France
| | - William Nasser
- Université de Lyon, INSA Lyon, Université Claude Bernard Lyon 1, CNRS, UMR 5240 MAP, Microbiologie, Adaptation, Pathogénie, Villeurbanne, France
| | - Sylvie Reverchon
- Université de Lyon, INSA Lyon, Université Claude Bernard Lyon 1, CNRS, UMR 5240 MAP, Microbiologie, Adaptation, Pathogénie, Villeurbanne, France
| | - Florence Hommais
- Université de Lyon, INSA Lyon, Université Claude Bernard Lyon 1, CNRS, UMR 5240 MAP, Microbiologie, Adaptation, Pathogénie, Villeurbanne, France
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Todhanakasem T, Triwattana K, Pom J, Havanapan P, Koombhongse P, Thitisak P. Physiological studies of the Pediococcus pentosaceus biofilm. Lett Appl Microbiol 2021; 72:178-186. [PMID: 33059384 DOI: 10.1111/lam.13351] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 06/25/2020] [Accepted: 07/05/2020] [Indexed: 12/19/2022]
Abstract
Pediococcus pentosaceus, a bacterium recently used in human and animal probiotics, was used in combination with supports made from polylactic acid composite soybean meal was used to study biofilm formation, and it was found that dense biofilms developed by Day 1. Proteomic comparison between planktonic and biofilm cultures of P. pentosaceus showed distinct expression patterns of intracellular and extracellular proteins. Type I glyceraldehyde-3-phosphate dehydrogenase was upregulated in biofilm cultures and mediated cell adhesion and encouraged biofilm production. GMP synthase, which regulates GMP synthesis and acts as an intracellular signal molecule to control cell mechanisms and has been exploited in the development of new therapeutic agents, was also upregulated in the biofilm mode of growth. The present work serves as a basis for future studies examining the complex network of systems that regulate lactic acid bacterial (LAB) biofilm formation and can serve as a framework for studies of production of therapeutic agents from LAB.
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Affiliation(s)
- T Todhanakasem
- Department of Agro-Industry, Faculty of Biotechnology, Assumption University, Bangkapi, Bangkok, Thailand
| | - K Triwattana
- Department of Agro-Industry, Faculty of Biotechnology, Assumption University, Bangkapi, Bangkok, Thailand
| | - J Pom
- Department of Agro-Industry, Faculty of Biotechnology, Assumption University, Bangkapi, Bangkok, Thailand
| | - P Havanapan
- Institute of Molecular Biosciences, Mahidol University, Salaya, Nakhon Pathom, Thailand
| | - P Koombhongse
- National Metal and Materials Technology Center (MTEC), Klong Luang, Thailand
| | - P Thitisak
- K.M.P. Biotech Co. Ltd, Chon Buri, Thailand
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Reverchon S, Meyer S, Forquet R, Hommais F, Muskhelishvili G, Nasser W. The nucleoid-associated protein IHF acts as a 'transcriptional domainin' protein coordinating the bacterial virulence traits with global transcription. Nucleic Acids Res 2021; 49:776-790. [PMID: 33337488 PMCID: PMC7826290 DOI: 10.1093/nar/gkaa1227] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 11/30/2020] [Accepted: 12/07/2020] [Indexed: 02/04/2023] Open
Abstract
Bacterial pathogenic growth requires a swift coordination of pathogenicity function with various kinds of environmental stress encountered in the course of host infection. Among the factors critical for bacterial adaptation are changes of DNA topology and binding effects of nucleoid-associated proteins transducing the environmental signals to the chromosome and coordinating the global transcriptional response to stress. In this study, we use the model phytopathogen Dickeya dadantii to analyse the organisation of transcription by the nucleoid-associated heterodimeric protein IHF. We inactivated the IHFα subunit of IHF thus precluding the IHFαβ heterodimer formation and determined both phenotypic effects of ihfA mutation on D. dadantii virulence and the transcriptional response under various conditions of growth. We show that ihfA mutation reorganises the genomic expression by modulating the distribution of chromosomal DNA supercoils at different length scales, thus affecting many virulence genes involved in both symptomatic and asymptomatic phases of infection, including those required for pectin catabolism. Altogether, we propose that IHF heterodimer is a 'transcriptional domainin' protein, the lack of which impairs the spatiotemporal organisation of transcriptional stress-response domains harbouring various virulence traits, thus abrogating the pathogenicity of D. dadantii.
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Affiliation(s)
- Sylvie Reverchon
- Univ Lyon, Université Claude Bernard Lyon 1, INSA-Lyon, CNRS, UMR5240 MAP, F-69622, France
| | - Sam Meyer
- Univ Lyon, Université Claude Bernard Lyon 1, INSA-Lyon, CNRS, UMR5240 MAP, F-69622, France
| | - Raphaël Forquet
- Univ Lyon, Université Claude Bernard Lyon 1, INSA-Lyon, CNRS, UMR5240 MAP, F-69622, France
| | - Florence Hommais
- Univ Lyon, Université Claude Bernard Lyon 1, INSA-Lyon, CNRS, UMR5240 MAP, F-69622, France
| | - Georgi Muskhelishvili
- Agricultural University of Georgia, School of Natural Sciences, 0159 Tbilisi, Georgia
| | - William Nasser
- Univ Lyon, Université Claude Bernard Lyon 1, INSA-Lyon, CNRS, UMR5240 MAP, F-69622, France
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12
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Abstract
Dickeya zeae is the etiological agent of bacterial foot rot disease, which can cause massive economic losses in banana and rice plantations. Genome sequence analysis showed that D. zeae strain EC1 contains multiple c-di-GMP turnover genes, but their roles and regulatory mechanisms in bacterial physiology and virulence remain vague. By generating consecutive in-frame deletion mutants of the genes encoding c-di-GMP biosynthesis and degradation, respectively, we analyzed the individual and collective impacts of these c-di-GMP metabolic genes on the c-di-GMP global pool, bacterial physiology, and virulence. The significance of our study is in identifying the mechanism of c-di-GMP signaling in strain EC1 more clearly, which expands the c-di-GMP regulating patterns in Gram-negative species. The methods and experimental designs in this research will provide a valuable reference for the exploration of the complex c-di-GMP regulation mechanisms in other bacteria. Dickeya zeae is an important and aggressive bacterial phytopathogen that can cause substantial economic losses in banana and rice plantations. We previously showed that c-di-GMP signaling proteins (cyclases/phosphodiesterases) in D. zeae strain EC1 play a significant role in the bacterial sessile-to-motile transition. To determine whether there is any synergistic effect among these c-di-GMP signaling proteins, we prepared a series of mutant strains by generating consecutive in-frame deletions of the genes encoding diguanylate cyclases (which make c-di-GMP) and phosphodiesterases (which break down c-di-GMP), respectively, using EC1 as a parental strain. The results showed that the complete deletion of all the putative diguanylate cyclases resulted in significantly increased bacterial motility and abrogated biofilm formation but did not appear to affect pathogenicity and virulence factor production. In contrast, the deletion of all the c-di-GMP phosphodiesterase genes disabled motility and prevented the invasion of EC1 into rice seeds. By measuring the c-di-GMP concentrations and swimming motility of all the mutants, we propose that c-di-GMP controlled swimming behavior through a multitiered program in a c-di-GMP concentration-dependent manner, which could be described as an L-shaped regression curve. These features are quite different from those that have been shown for other bacterial species such as Salmonella and Caulobacter crescentus. Further analysis identified three c-di-GMP signaling proteins, i.e., PDE10355, DGC14945, and PDE14950, that play dominant roles in influencing the global c-di-GMP pool of strain EC1. The findings from this study highlight the complexity and plasticity of c-di-GMP regulatory circuits in different bacterial species.
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13
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Rieusset L, Rey M, Muller D, Vacheron J, Gerin F, Dubost A, Comte G, Prigent-Combaret C. Secondary metabolites from plant-associated Pseudomonas are overproduced in biofilm. Microb Biotechnol 2020; 13:1562-1580. [PMID: 33000552 PMCID: PMC7415375 DOI: 10.1111/1751-7915.13598] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 04/29/2020] [Accepted: 04/30/2020] [Indexed: 02/06/2023] Open
Abstract
Plant rhizosphere soil houses complex microbial communities in which microorganisms are often involved in intraspecies as well as interspecies and inter-kingdom signalling networks. Some members of these networks can improve plant health thanks to an important diversity of bioactive secondary metabolites. In this competitive environment, the ability to form biofilms may provide major advantages to microorganisms. With the aim of highlighting the impact of bacterial lifestyle on secondary metabolites production, we performed a metabolomic analysis on four fluorescent Pseudomonas strains cultivated in planktonic and biofilm colony conditions. The untargeted metabolomic analysis led to the detection of hundreds of secondary metabolites in culture extracts. Comparison between biofilm and planktonic conditions showed that bacterial lifestyle is a key factor influencing Pseudomonas metabolome. More than 50% of the detected metabolites were differentially produced according to planktonic or biofilm lifestyles, with the four Pseudomonas strains overproducing several secondary metabolites in biofilm conditions. In parallel, metabolomic analysis associated with genomic prediction and a molecular networking approach enabled us to evaluate the impact of bacterial lifestyle on chemically identified secondary metabolites, more precisely involved in microbial interactions and plant-growth promotion. Notably, this work highlights the major effect of biofilm lifestyle on acyl-homoserine lactone and phenazine production in P. chlororaphis strains.
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Affiliation(s)
- Laura Rieusset
- CNRS UMR-5557, INRAe UMR-1418, Ecologie Microbienne, VetAgroSup, Université de Lyon, Université Claude Bernard Lyon1, 43 Boulevard du 11 novembre 1918, Villeurbanne, 69622, France
| | - Marjolaine Rey
- CNRS UMR-5557, INRAe UMR-1418, Ecologie Microbienne, VetAgroSup, Université de Lyon, Université Claude Bernard Lyon1, 43 Boulevard du 11 novembre 1918, Villeurbanne, 69622, France
| | - Daniel Muller
- CNRS UMR-5557, INRAe UMR-1418, Ecologie Microbienne, VetAgroSup, Université de Lyon, Université Claude Bernard Lyon1, 43 Boulevard du 11 novembre 1918, Villeurbanne, 69622, France
| | - Jordan Vacheron
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, 1015, Switzerland
| | - Florence Gerin
- CNRS UMR-5557, INRAe UMR-1418, Ecologie Microbienne, VetAgroSup, Université de Lyon, Université Claude Bernard Lyon1, 43 Boulevard du 11 novembre 1918, Villeurbanne, 69622, France
| | - Audrey Dubost
- CNRS UMR-5557, INRAe UMR-1418, Ecologie Microbienne, VetAgroSup, Université de Lyon, Université Claude Bernard Lyon1, 43 Boulevard du 11 novembre 1918, Villeurbanne, 69622, France
| | - Gilles Comte
- CNRS UMR-5557, INRAe UMR-1418, Ecologie Microbienne, VetAgroSup, Université de Lyon, Université Claude Bernard Lyon1, 43 Boulevard du 11 novembre 1918, Villeurbanne, 69622, France
| | - Claire Prigent-Combaret
- CNRS UMR-5557, INRAe UMR-1418, Ecologie Microbienne, VetAgroSup, Université de Lyon, Université Claude Bernard Lyon1, 43 Boulevard du 11 novembre 1918, Villeurbanne, 69622, France
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14
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Biocontrol Properties and Functional Characterization of Rice Rhizobacterium Pseudomonas sp. VSMKU4036. JOURNAL OF PURE AND APPLIED MICROBIOLOGY 2020. [DOI: 10.22207/jpam.14.2.53] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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15
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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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16
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Lemon-Fruit-Based Green Synthesis of Zinc Oxide Nanoparticles and Titanium Dioxide Nanoparticles against Soft Rot Bacterial Pathogen Dickeya dadantii. Biomolecules 2019; 9:biom9120863. [PMID: 31835898 PMCID: PMC6995516 DOI: 10.3390/biom9120863] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 12/05/2019] [Accepted: 12/05/2019] [Indexed: 11/30/2022] Open
Abstract
Edible plant fruits are safe raw materials free of toxicants and rich in biomolecules for reducing metal ions and stabilizing nanoparticles. Zinc oxide nanoparticles (ZnONPs) and titanium dioxide nanoparticles (TiO2NPs) are the most produced consumer nanomaterials and have known antibacterial activities but have rarely been used against phytopathogenic bacteria. Here, we synthesized ZnONPs and TiO2NPs simply by mixing ZnO or TiO2 solution with a lemon fruit extract at room temperature and showed their antibacterial activities against Dickeya dadantii, which causes sweet potato stem and root rot disease occurring in major sweet potato planting areas in China. Ultraviolet–visible spectrometry and energy dispersive spectroscopy determined their physiochemical characteristics. Transmission electron microscopy, scanning electron microscopy, and X-ray diffraction spectroscopy revealed the nanoscale size and polymorphic crystalline structures of the ZnONPs and TiO2NPs. Fourier-transform infrared spectroscopy revealed their surface stabilization groups from the lemon fruit extract. In contrast to ZnO and TiO2, which had no antibacterial activity against D. dadantii, ZnONPs and TiO2NPs showed inhibitions on D. dadantii growth, swimming motility, biofilm formation, and maceration of sweet potato tuber slices. ZnONPs and TiO2NPs showed similar extents of antibacterial activities, which increased with the increase of nanoparticle concentrations, and inhibited about 60% of D. dadantii activities at the concentration of 50 µg∙mL−1. The green synthetic ZnONPs and TiO2NPs can be used to control the sweet potato soft rot disease by control of pathogen contamination of seed tubers.
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17
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Ashitha A, Midhun S, Sunil M, Nithin T, Radhakrishnan E, Mathew J. Bacterial endophytes from Artemisia nilagirica (Clarke) Pamp., with antibacterial efficacy against human pathogens. Microb Pathog 2019; 135:103624. [DOI: 10.1016/j.micpath.2019.103624] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 06/03/2019] [Accepted: 07/16/2019] [Indexed: 11/17/2022]
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18
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Gawade P, Gunjal G, Sharma A, Ghosh P. Reconstruction of transcriptional regulatory networks of Fis and H-NS in Escherichia coli from genome-wide data analysis. Genomics 2019; 112:1264-1272. [PMID: 31356968 DOI: 10.1016/j.ygeno.2019.07.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Revised: 07/24/2019] [Accepted: 07/25/2019] [Indexed: 11/29/2022]
Abstract
Fis (Factor for inversion stimulation) and H-NS (Histone-like nucleoid-structuring protein) are two well-known nucleoid-associated proteins (NAPs) in proteobacteria, which play crucial roles in genome organization and transcriptional regulation. We performed RNA-sequencing to identify genes regulated by these NAPs. Study reveals that Fis and H-NS affect expression of 462 and 88 genes respectively in Escherichia coli at mid-exponential growth phase. By integrating available ChIP-seq data, we identified direct and indirect regulons of Fis and H-NS proteins. Functional analysis reveals that Fis controls expression of genes involved in translation, oxidative phosphorylation, sugar metabolism and transport, amino acid metabolism, bacteriocin transport, cell division, two-component system, biofilm formation, pilus organization and lipopolysaccharide biosynthesis pathways. However, H-NS represses expression of genes in cell adhesion, recombination, biofilm formation and lipopolysaccharide biosynthesis pathways under mid-exponential growth condition. The current regulatory networks thus provide a global glimpse of coordinated regulatory roles for these two important NAPs.
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Affiliation(s)
- Priyanka Gawade
- Bioinformatics Centre, Savitribai Phule Pune University, Pune 411007, India
| | - Gaurav Gunjal
- Department of Biotechnology, Savitribai Phule Pune University, Pune 411007, India
| | - Anamika Sharma
- Department of Biotechnology, Savitribai Phule Pune University, Pune 411007, India
| | - Payel Ghosh
- Bioinformatics Centre, Savitribai Phule Pune University, Pune 411007, India.
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19
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Hossain A, Hong X, Ibrahim E, Li B, Sun G, Meng Y, Wang Y, An Q. Green Synthesis of Silver Nanoparticles with Culture Supernatant of a Bacterium Pseudomonas rhodesiae and Their Antibacterial Activity against Soft Rot Pathogen Dickeya dadantii. Molecules 2019; 24:molecules24122303. [PMID: 31234369 PMCID: PMC6631663 DOI: 10.3390/molecules24122303] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 06/15/2019] [Accepted: 06/19/2019] [Indexed: 01/25/2023] Open
Abstract
Bacterial stem and root rot disease of sweet potato caused by Dickeya dadantii recently broke out in major sweet potato planting areas in China and calls for effective approaches to control the pathogen and disease. Here, we developed a simple method for green synthesis of silver nanoparticles (AgNPs) using bacterial culture supernatants. AgNPs synthesized with the cell-free culture supernatant of a bacterium Pseudomonas rhodesiae displayed the characteristic surface plasmon resonance peak at 420–430 nm and as nanocrystallites in diameters of 20–100 nm determined by transmission electron microscopy, scanning electron microscopy, and X-ray diffraction spectroscopy. Functional groups associated with proteins in the culture supernatant may reduce silver ions and stabilize AgNPs. The AgNPs showed antibacterial activities against D. dadantii growth, swimming motility, biofilm formation, and maceration of sweet potato tubers whereas the culture supernatant of P. rhodesiae did not. AgNPs (12 µg∙ml−1) and AgNO3 (50 µg∙ml−1) showed close antibacterial activities. The antibacterial activities increased with the increase of AgNP concentrations. The green-synthesized AgNPs can be used to control the soft rot disease by control of pathogen contamination of sweet potato seed tubers.
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Affiliation(s)
- Afsana Hossain
- State Key Laboratory of Rice Biology and Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China.
- Department of Plant Pathology and Seed Science, Sylhet Agricultural University, Sylhet 3100, Bangladesh.
| | - Xianxian Hong
- State Key Laboratory of Rice Biology and Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China.
| | - Ezzeldin Ibrahim
- State Key Laboratory of Rice Biology and Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China.
| | - Bin Li
- State Key Laboratory of Rice Biology and Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China.
| | - Guochang Sun
- State Key Laboratory for Quality and Safety of Agro-products (in prepared), Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.
| | - Youqing Meng
- General Station of Plant Protection and Quarantine of Zhejiang Province, Hangzhou 310020, China.
| | - Yanli Wang
- State Key Laboratory for Quality and Safety of Agro-products (in prepared), Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.
| | - Qianli An
- State Key Laboratory of Rice Biology and Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China.
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20
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Duprey A, Taib N, Leonard S, Garin T, Flandrois JP, Nasser W, Brochier-Armanet C, Reverchon S. The phytopathogenic nature of Dickeya aquatica 174/2 and the dynamic early evolution of Dickeya pathogenicity. Environ Microbiol 2019; 21:2809-2835. [PMID: 30969462 DOI: 10.1111/1462-2920.14627] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 04/04/2019] [Accepted: 04/08/2019] [Indexed: 12/13/2022]
Abstract
Dickeya is a genus of phytopathogenic enterobacterales causing soft rot in a variety of plants (e.g. potato, chicory, maize). Among the species affiliated to this genus, Dickeya aquatica, described in 2014, remained particularly mysterious because it had no known host. Furthermore, while D. aquatica was proposed to represent a deep-branching species among Dickeya genus, its precise phylogenetic position remained elusive. Here, we report the complete genome sequence of the D. aquatica type strain 174/2. We demonstrate the affinity of D. aquatica strain 174/2 for acidic fruits such as tomato and cucumber and show that exposure of this bacterium to acidic pH induces twitching motility. An in-depth phylogenomic analysis of all available Dickeya proteomes pinpoints D. aquatica as the second deepest branching lineage within this genus and reclassifies two lineages that likely correspond to new genomospecies (gs.): Dickeya gs. poaceaephila (Dickeya sp NCPPB 569) and Dickeya gs. undicola (Dickeya sp 2B12), together with a new putative genus, tentatively named Prodigiosinella. Finally, from comparative analyses of Dickeya proteomes, we infer the complex evolutionary history of this genus, paving the way to study the adaptive patterns and processes of Dickeya to different environmental niches and hosts. In particular, we hypothesize that the lack of xylanases and xylose degradation pathways in D. aquatica could reflect adaptation to aquatic charophyte hosts which, in contrast to land plants, do not contain xyloglucans.
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Affiliation(s)
- Alexandre Duprey
- Univ Lyon, Université Claude Bernard Lyon 1, INSA-Lyon, CNRS, UMR5240, Microbiologie, Adaptation et Pathogénie, 10 Rue Raphaël Dubois, 69622, Villeurbanne, France
| | - Najwa Taib
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, UMR5558, Laboratoire de Biométrie et Biologie Évolutive, 43 bd du 11 novembre 1918, 69622, Villeurbanne, France
| | - Simon Leonard
- Univ Lyon, Université Claude Bernard Lyon 1, INSA-Lyon, CNRS, UMR5240, Microbiologie, Adaptation et Pathogénie, 10 Rue Raphaël Dubois, 69622, Villeurbanne, France
| | - Tiffany Garin
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, UMR5558, Laboratoire de Biométrie et Biologie Évolutive, 43 bd du 11 novembre 1918, 69622, Villeurbanne, France
| | - Jean-Pierre Flandrois
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, UMR5558, Laboratoire de Biométrie et Biologie Évolutive, 43 bd du 11 novembre 1918, 69622, Villeurbanne, France
| | - William Nasser
- Univ Lyon, Université Claude Bernard Lyon 1, INSA-Lyon, CNRS, UMR5240, Microbiologie, Adaptation et Pathogénie, 10 Rue Raphaël Dubois, 69622, Villeurbanne, France
| | - Céline Brochier-Armanet
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, UMR5558, Laboratoire de Biométrie et Biologie Évolutive, 43 bd du 11 novembre 1918, 69622, Villeurbanne, France
| | - Sylvie Reverchon
- Univ Lyon, Université Claude Bernard Lyon 1, INSA-Lyon, CNRS, UMR5240, Microbiologie, Adaptation et Pathogénie, 10 Rue Raphaël Dubois, 69622, Villeurbanne, France
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21
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Pérez-Mendoza D, Felipe A, Ferreiro MD, Sanjuán J, Gallegos MT. AmrZ and FleQ Co-regulate Cellulose Production in Pseudomonas syringae pv. Tomato DC3000. Front Microbiol 2019; 10:746. [PMID: 31057500 PMCID: PMC6478803 DOI: 10.3389/fmicb.2019.00746] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 03/25/2019] [Indexed: 12/28/2022] Open
Abstract
Pseudomonas syringae pv. tomato DC3000 carries the wssABCDEFGHI operon for the synthesis of acetylated cellulose, whose production is stimulated by increasing the intracellular levels of the second messenger c-di-GMP. This enhances air-liquid biofilm formation and generates a wrinkly colony morphotype in solid media. In the present study we show that cellulose production is a complex process regulated at multiple levels and involving different players in this bacterium. Using different in vitro approaches, including Electrophoretic Mobility Shift Assay (EMSA) and footprint analysis, we demonstrated the interrelated role of two transcriptional regulators, AmrZ and FleQ, over cellulose production in Pto DC3000 and the influence of c-di-GMP in this process. Under physiological c-di-GMP levels, both regulators bind directly to adjacent regions at the wss promoter inhibiting its expression. However, just FleQ responds to c-di-GMP releasing from its wss operator site and converting from a repressor to an activator of cellulose production. The additive effect of the double amrZ/fleQ mutation on the expression of wss, together with the fact that they are not cross-regulated at the transcriptional level, suggest that FleQ and AmrZ behave as independent regulators, unlike what has been described in other Pseudomonas species. Furthermore, this dual co-regulation exerted by AmrZ and FleQ is not limited to cellulose production, but also affects other important phenotypes in Pto DC3000, such as motility and virulence.
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Affiliation(s)
- Daniel Pérez-Mendoza
- Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín (EEZ-CSIC), Granada, Spain
| | - Antonia Felipe
- Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín (EEZ-CSIC), Granada, Spain
| | - María Dolores Ferreiro
- Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín (EEZ-CSIC), Granada, Spain
| | - Juan Sanjuán
- Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín (EEZ-CSIC), Granada, Spain
| | - María Trinidad Gallegos
- Department of Soil Microbiology and Symbiotic Systems, Estación Experimental del Zaidín (EEZ-CSIC), Granada, Spain
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22
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NapA (Rv0430), a Novel Nucleoid-Associated Protein that Regulates a Virulence Operon in Mycobacterium tuberculosis in a Supercoiling-Dependent Manner. J Mol Biol 2019; 431:1576-1591. [DOI: 10.1016/j.jmb.2019.02.029] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Revised: 02/23/2019] [Accepted: 02/25/2019] [Indexed: 12/17/2022]
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23
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In Vitro Formation of Dickeya zeae MS1 Biofilm. Curr Microbiol 2018; 76:100-107. [PMID: 30390102 DOI: 10.1007/s00284-018-1593-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 10/29/2018] [Indexed: 10/28/2022]
Abstract
Bacterial soft rot caused by Dickeya zeae MS1 (Erwinia chrysanthemi) is one of the most devastating banana diseases worldwide. However, knowledge of the development and ecological interactions of D. zeae MS1 biofilm is limited. Here, we visualized the development and architecture of D. zeae MS1 biofilm using confocal laser scanning microscopy, and we evaluated the ability of D. zeae MS1 to form biofilms under different environmental conditions (carbon sources, temperatures, pH levels and mineral elements) using a microtiter plate assay. We found that the development of D. zeae MS1 biofilm could be categorized into four phases and that mature biofilm consisted of a highly organized architecture of both bacterial cells and a self-produced matrix of extracellular polysaccharides. Furthermore, sucrose was the most suitable carbon source for supporting the growth of biofilm cells and that 32 °C and pH 7.0 were the most favorable of the temperatures and pH levels examined. Meanwhile, the addition of Ca2+, Fe2+, K+ and Na+ enhanced the formation of biofilm in minimal medium cultures, whereas 2.5 mM Cu2+ and Mn2+ was inhibitory. A better understanding of biofilm formation under different environmental parameters will improve our knowledge of the growth kinetics of D. zeae MS1 biofilm.
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Environmental conditions shape the biofilm of the Antarctic bacterium Pseudoalteromonas haloplanktis TAC125. Microbiol Res 2018; 218:66-75. [PMID: 30454660 DOI: 10.1016/j.micres.2018.09.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 09/24/2018] [Accepted: 09/28/2018] [Indexed: 11/21/2022]
Abstract
Biofilms are the most widely distributed and successful microbial modes of life. The capacity of bacteria to colonize surfaces provides stability in the growth environment, allows the capturing of nutrients and affords protection from a range of environmental challenges and stress. Bacteria living in cold environments, like Antarctica, can be found as biofilms, even though the mechanisms of how this lifestyle is related to their environmental adaptation have been poorly investigated. In this paper, the biofilm of Pseudoalteromonas haloplanktis TAC125, one of the model organisms of cold-adapted bacteria, has been characterized in terms of biofilm typology and matrix composition. The characterization was performed on biofilms produced by the bacterium in response to different nutrient abundance and temperatures; in particular, this is the first report describing the structure of a biofilm formed at 0 °C. The results reported demonstrate that PhTAC125 produces biofilms in different amount and endowed with different physico-chemical properties, like hydrophobicity and roughness, by modulating the relative amount of the different macromolecules present in the biofilm matrix. The capability of PhTAC125 to adopt different biofilm structures in response to environment changes appears to be an interesting adaptation strategy and gives the first hints about the biofilm formation in cold environments.
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25
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Besset-Manzoni Y, Rieusset L, Joly P, Comte G, Prigent-Combaret C. Exploiting rhizosphere microbial cooperation for developing sustainable agriculture strategies. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:29953-29970. [PMID: 29313197 DOI: 10.1007/s11356-017-1152-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 12/26/2017] [Indexed: 05/23/2023]
Abstract
The rhizosphere hosts a considerable microbial community. Among that community, bacteria called plant growth-promoting rhizobacteria (PGPR) can promote plant growth and defense against diseases using diverse distinct plant-beneficial functions. Crop inoculation with PGPR could allow to reduce the use of pesticides and fertilizers in agrosystems. However, microbial crop protection and growth stimulation would be more efficient if cooperation between rhizosphere bacterial populations was taken into account when developing biocontrol agents and biostimulants. Rhizospheric bacteria live in multi-species biofilms formed all along the root surface or sometimes inside the plants (i.e., endophyte). PGPR cooperate with their host plants and also with other microbial populations inside biofilms. These interactions are mediated by a large diversity of microbial metabolites and physical signals that trigger cell-cell communication and appropriate responses. A better understanding of bacterial behavior and microbial cooperation in the rhizosphere could allow for a more successful use of bacteria in sustainable agriculture. This review presents an ecological view of microbial cooperation in agrosystems and lays the emphasis on the main microbial metabolites involved in microbial cooperation, plant health protection, and plant growth stimulation. Eco-friendly inoculant consortia that will foster microbe-microbe and microbe-plant cooperation can be developed to promote crop growth and restore biodiversity and functions lost in agrosystems.
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Affiliation(s)
- Yoann Besset-Manzoni
- UMR Ecologie Microbienne, CNRS, INRA, VetAgro Sup, UCBL, Université de Lyon, 43 bd du 11 Novembre 1918, F-69622, Villeurbanne cedex, France
- Biovitis, 15 400, Saint Etienne-de-Chomeil, France
| | - Laura Rieusset
- UMR Ecologie Microbienne, CNRS, INRA, VetAgro Sup, UCBL, Université de Lyon, 43 bd du 11 Novembre 1918, F-69622, Villeurbanne cedex, France
| | - Pierre Joly
- Biovitis, 15 400, Saint Etienne-de-Chomeil, France
| | - Gilles Comte
- UMR Ecologie Microbienne, CNRS, INRA, VetAgro Sup, UCBL, Université de Lyon, 43 bd du 11 Novembre 1918, F-69622, Villeurbanne cedex, France
| | - Claire Prigent-Combaret
- UMR Ecologie Microbienne, CNRS, INRA, VetAgro Sup, UCBL, Université de Lyon, 43 bd du 11 Novembre 1918, F-69622, Villeurbanne cedex, France.
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Gutierrez-Pacheco M, Gonzalez-Aguilar G, Martinez-Tellez M, Lizardi-Mendoza J, Madera-Santana T, Bernal-Mercado A, Vazquez-Armenta F, Ayala-Zavala J. Carvacrol inhibits biofilm formation and production of extracellular polymeric substances of Pectobacterium carotovorum subsp. carotovorum. Food Control 2018. [DOI: 10.1016/j.foodcont.2018.02.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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27
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Fis is a global regulator critical for modulation of virulence factor production and pathogenicity of Dickeya zeae. Sci Rep 2018; 8:341. [PMID: 29321600 PMCID: PMC5762655 DOI: 10.1038/s41598-017-18578-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 12/11/2017] [Indexed: 12/25/2022] Open
Abstract
Dickeya zeae is the causal agent of rice foot rot disease, which has recently become a great threat to rice planting countries and regions. The pathogen produces a family of phytotoxins named zeamines that is critical for bacterial virulence, but little is known about the signaling pathways and regulatory mechanisms that govern zeamine production. In this study, we showed that a conserved transcriptional regulator Fis is involved in the regulation of zeamine production in D. zeae strain EC1. Deletion mutants were markedly attenuated in the virulence against rice seed germination. Transcriptome and phenotype analyses showed that Fis is a potent global transcriptional regulator modulating various virulence traits, including production of extracellular enzymes and exopolysaccharides, swimming and swarming motility, biofilm formation and cell aggregation. DNA gel retardation analysis showed that Fis directly regulates the transcription of key virulence genes and the genes encoding Vfm quorum sensing system through DNA/protein interaction. Our findings unveil a key regulator associated with the virulence of D. zeae EC1, and present useful clues for further elucidation of the regulatory complex and signaling pathways which govern the virulence of this important pathogen.
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Ainelo H, Lahesaare A, Teppo A, Kivisaar M, Teras R. The promoter region of lapA and its transcriptional regulation by Fis in Pseudomonas putida. PLoS One 2017; 12:e0185482. [PMID: 28945818 PMCID: PMC5612765 DOI: 10.1371/journal.pone.0185482] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 09/13/2017] [Indexed: 12/28/2022] Open
Abstract
LapA is the biggest protein in Pseudomonas putida and a key factor for biofilm formation. Its importance and posttranslational regulation is rather thoroughly studied but less is known about the transcriptional regulation. Here we give evidence that transcription of lapA in LB-grown bacteria is initiated from six promoters, three of which display moderate RpoS-dependence. The global transcription regulator Fis binds to the lapA promoter area at six positions in vitro, and Fis activates the transcription of lapA while overexpressed in cells. Two of the six Fis binding sites, Fis-A7 and Fis-A5, are necessary for the positive effect of Fis on the transcription of lapA in vivo. Our results indicate that Fis binding to the Fis-A7 site increases the level of transcription from the most distal promoter of lapA, whereas Fis binding to the Fis-A5 site could be important for modifying the promoter area topology.
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Affiliation(s)
- Hanna Ainelo
- Chair of Genetics, Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Andrio Lahesaare
- Chair of Genetics, Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Annika Teppo
- Chair of Genetics, Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Maia Kivisaar
- Chair of Genetics, Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Riho Teras
- Chair of Genetics, Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
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29
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Echeverz M, García B, Sabalza A, Valle J, Gabaldón T, Solano C, Lasa I. Lack of the PGA exopolysaccharide in Salmonella as an adaptive trait for survival in the host. PLoS Genet 2017; 13:e1006816. [PMID: 28542593 PMCID: PMC5464674 DOI: 10.1371/journal.pgen.1006816] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 06/08/2017] [Accepted: 05/12/2017] [Indexed: 12/22/2022] Open
Abstract
Many bacteria build biofilm matrices using a conserved exopolysaccharide named PGA or PNAG (poly-β-1,6-N-acetyl-D-glucosamine). Interestingly, while E. coli and other members of the family Enterobacteriaceae encode the pgaABCD operon responsible for PGA synthesis, Salmonella lacks it. The evolutionary force driving this difference remains to be determined. Here, we report that Salmonella lost the pgaABCD operon after the divergence of Salmonella and Citrobacter clades, and previous to the diversification of the currently sequenced Salmonella strains. Reconstitution of the PGA machinery endows Salmonella with the capacity to produce PGA in a cyclic dimeric GMP (c-di-GMP) dependent manner. Outside the host, the PGA polysaccharide does not seem to provide any significant benefit to Salmonella: resistance against chlorine treatment, ultraviolet light irradiation, heavy metal stress and phage infection remained the same as in a strain producing cellulose, the main biofilm exopolysaccharide naturally produced by Salmonella. In contrast, PGA production proved to be deleterious to Salmonella survival inside the host, since it increased susceptibility to bile salts and oxidative stress, and hindered the capacity of S. Enteritidis to survive inside macrophages and to colonize extraintestinal organs, including the gallbladder. Altogether, our observations indicate that PGA is an antivirulence factor whose loss may have been a necessary event during Salmonella speciation to permit survival inside the host. During bacterial evolution, specific traits that optimize the organism’s fitness are selected. The production of exopolysaccharides is widespread among bacteria in which they play a protective shielding role as main constituents of biofilms. In contrast to closely related siblings, Salmonella has lost the capacity to produce the exopolysaccharide PGA. Our study reveals that Salmonella lost pga genes, and that the driving force for such a loss may have been the detrimental impact that PGA has during Salmonella invasion of internal organs where it augments the susceptibility to bile salts and oxygen radicals, reducing bacterial survival inside macrophages and rendering Salmonella avirulent. These results suggest that gene-loss has played an important role during Salmonella evolution.
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Affiliation(s)
- Maite Echeverz
- Navarrabiomed-Universidad Pública de Navarra-Departamento de Salud, IDISNA, Pamplona, Spain
| | - Begoña García
- Navarrabiomed-Universidad Pública de Navarra-Departamento de Salud, IDISNA, Pamplona, Spain
| | - Amaia Sabalza
- Navarrabiomed-Universidad Pública de Navarra-Departamento de Salud, IDISNA, Pamplona, Spain
| | - Jaione Valle
- Navarrabiomed-Universidad Pública de Navarra-Departamento de Salud, IDISNA, Pamplona, Spain
| | - Toni Gabaldón
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Cristina Solano
- Navarrabiomed-Universidad Pública de Navarra-Departamento de Salud, IDISNA, Pamplona, Spain
- * E-mail: (CS); (IL)
| | - Iñigo Lasa
- Navarrabiomed-Universidad Pública de Navarra-Departamento de Salud, IDISNA, Pamplona, Spain
- * E-mail: (CS); (IL)
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30
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Deng X, Li M, Pan X, Zheng R, Liu C, Chen F, Liu X, Cheng Z, Jin S, Wu W. Fis Regulates Type III Secretion System by Influencing the Transcription of exsA in Pseudomonas aeruginosa Strain PA14. Front Microbiol 2017; 8:669. [PMID: 28469612 PMCID: PMC5395579 DOI: 10.3389/fmicb.2017.00669] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 03/31/2017] [Indexed: 11/21/2022] Open
Abstract
Fis is a versatile DNA binding protein in bacteria. It has been demonstrated in multiple bacteria that Fis plays crucial roles in regulating bacterial virulence factors and optimizing bacterial adaptation to various environments. However, the role of Fis in Pseudomonas aeruginosa virulence as well as gene regulation remains largely unknown. Here, we found that Fis was required for the virulence of P. aeruginosa in a murine acute pneumonia model. Transcriptome analysis revealed that expression of T3SS genes, including master regulator ExsA, was defective in a fis::Tn mutant. We further demonstrate that the continuous transcription of exsC, exsE, exsB, and exsA driven by the exsC promoter was required for the activation of T3SS. Fis was found to specifically bind to the exsB-exsA intergenic region and plays an essential role in the transcription elongation from exsB to exsA. Therefore, we found a novel role of Fis in the regulation of exsA expression.
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Affiliation(s)
- Xuan Deng
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai UniversityTianjin, China
| | - Mei Li
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai UniversityTianjin, China
| | - Xiaolei Pan
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai UniversityTianjin, China
| | - Ruiping Zheng
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai UniversityTianjin, China
| | - Chang Liu
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai UniversityTianjin, China
| | - Fei Chen
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai UniversityTianjin, China
| | - Xue Liu
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai UniversityTianjin, China
| | - Zhihui Cheng
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai UniversityTianjin, China
| | - Shouguang Jin
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai UniversityTianjin, China.,Department of Molecular Genetics and Microbiology, College of Medicine, University of FloridaGainesville, FL, USA
| | - Weihui Wu
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai UniversityTianjin, China
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31
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Pandin C, Le Coq D, Canette A, Aymerich S, Briandet R. Should the biofilm mode of life be taken into consideration for microbial biocontrol agents? Microb Biotechnol 2017; 10:719-734. [PMID: 28205337 PMCID: PMC5481536 DOI: 10.1111/1751-7915.12693] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 01/19/2017] [Accepted: 01/20/2017] [Indexed: 11/26/2022] Open
Abstract
Almost one‐third of crop yields are lost every year due to microbial alterations and diseases. The main control strategy to limit these losses is the use of an array of chemicals active against spoilage and unwanted pathogenic microorganisms. Their massive use has led to extensive environmental pollution, human poisoning and a variety of diseases. An emerging alternative to this chemical approach is the use of microbial biocontrol agents. Biopesticides have been used with success in several fields, but a better understanding of their mode of action is necessary to better control their activity and increase their use. Very few studies have considered that biofilms are the preferred mode of life of microorganisms in the target agricultural biotopes. Increasing evidence shows that the spatial organization of microbial communities on crop surfaces may drive important bioprotection mechanisms. The aim of this review is to summarize the evidence of biofilm formation by biocontrol agents on crops and discuss how this surface‐associated mode of life may influence their biology and interactions with other microorganisms and the host and, finally, their overall beneficial activity.
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Affiliation(s)
- Caroline Pandin
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Dominique Le Coq
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France.,Micalis Institute, INRA, AgroParisTech, CNRS, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Alexis Canette
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Stéphane Aymerich
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Romain Briandet
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
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32
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Leonard S, Hommais F, Nasser W, Reverchon S. Plant-phytopathogen interactions: bacterial responses to environmental and plant stimuli. Environ Microbiol 2017; 19:1689-1716. [DOI: 10.1111/1462-2920.13611] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 11/09/2016] [Accepted: 11/16/2016] [Indexed: 01/06/2023]
Affiliation(s)
- Simon Leonard
- University of Lyon, Université Claude Bernard Lyon 1; INSA-Lyon, CNRS, UMR5240, Microbiologie, Adaptation, Pathogénie, 10 rue Raphaël Dubois Villeurbanne F-69622 France
| | - Florence Hommais
- University of Lyon, Université Claude Bernard Lyon 1; INSA-Lyon, CNRS, UMR5240, Microbiologie, Adaptation, Pathogénie, 10 rue Raphaël Dubois Villeurbanne F-69622 France
| | - William Nasser
- University of Lyon, Université Claude Bernard Lyon 1; INSA-Lyon, CNRS, UMR5240, Microbiologie, Adaptation, Pathogénie, 10 rue Raphaël Dubois Villeurbanne F-69622 France
| | - Sylvie Reverchon
- University of Lyon, Université Claude Bernard Lyon 1; INSA-Lyon, CNRS, UMR5240, Microbiologie, Adaptation, Pathogénie, 10 rue Raphaël Dubois Villeurbanne F-69622 France
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34
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Ahmad I, Rouf SF, Sun L, Cimdins A, Shafeeq S, Le Guyon S, Schottkowski M, Rhen M, Römling U. BcsZ inhibits biofilm phenotypes and promotes virulence by blocking cellulose production in Salmonella enterica serovar Typhimurium. Microb Cell Fact 2016; 15:177. [PMID: 27756305 PMCID: PMC5070118 DOI: 10.1186/s12934-016-0576-6] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 10/03/2016] [Indexed: 02/04/2023] Open
Abstract
Background Cellulose, a 1,4 beta-glucan polysaccharide, is produced by a variety of organisms including bacteria. Although the production of cellulose has a high biological, ecological and economical impact, regulatory mechanisms of cellulose biosynthesis are mostly unknown. Family eight cellulases are regularly associated with cellulose biosynthesis operons in bacteria; however, their function is poorly characterized. In this study, we analysed the role of the cellulase BcsZ encoded by the bcsABZC cellulose biosynthesis operon of Salmonella enterica serovar Typhimurium (S. Typhimurium) in biofilm related behavior. We also investigated the involvement of BcsZ in pathogenesis of S. Typhimurium including a murine typhoid fever infection model. Result In S. Typhimurium, cellulase BcsZ with a putative periplasmic location negatively regulates cellulose biosynthesis. Moreover, as assessed with a non-polar mutant, BcsZ affects cellulose-associated phenotypes such as the rdar biofilm morphotype, cell clumping, biofilm formation, pellicle formation and flagella-dependent motility. Strikingly, although upregulation of cellulose biosynthesis was not observed on agar plate medium at 37 °C, BcsZ is required for efficient pathogen-host interaction. Key virulence phenotypes of S. Typhimurium such as invasion of epithelial cells and proliferation in macrophages were positively regulated by BcsZ. Further on, a bcsZ mutant was outcompeted by the wild type in organ colonization in the murine typhoid fever infection model. Selected phenotypes were relieved upon deletion of the cellulose synthase BcsA and/or the central biofilm activator CsgD. Conclusion Although the protein scaffold has an additional physiological role, our findings indicate that the catalytic activity of BcsZ effectively downregulates CsgD activated cellulose biosynthesis. Repression of cellulose production by BcsZ subsequently enables Salmonella to efficiently colonize the host. Electronic supplementary material The online version of this article (doi:10.1186/s12934-016-0576-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Irfan Ahmad
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.,Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Syed Fazle Rouf
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.,Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Quebec, Canada
| | - Lei Sun
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Annika Cimdins
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Sulman Shafeeq
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Soazig Le Guyon
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Marco Schottkowski
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Mikael Rhen
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Ute Römling
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.
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35
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Reverchon S, Muskhelisvili G, Nasser W. Virulence Program of a Bacterial Plant Pathogen: The Dickeya Model. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2016; 142:51-92. [PMID: 27571692 DOI: 10.1016/bs.pmbts.2016.05.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The pectinolytic Dickeya spp. are Gram-negative bacteria causing severe disease in a wide range of plant species. Although the Dickeya genus was initially restricted to tropical and subtropical areas, two Dickeya species (D. dianthicola and D. solani) emerged recently in potato cultures in Europe. Soft-rot, the visible symptoms, is caused by plant cell wall degrading enzymes, mainly pectate lyases (Pels) that cleave the pectin polymer. However, an efficient colonization of the host requires many additional elements including early factors (eg, flagella, lipopolysaccharide, and exopolysaccharide) that allow adhesion of the bacteria and intermediate factors involved in adaptation to new growth conditions encountered in the host (eg, oxidative stress, iron starvation, and toxic compounds). To facilitate this adaptation, Dickeya have developed complex regulatory networks ensuring appropriate expression of virulence genes. This review presents recent advances in our understanding of the signals and genetic circuits impacting the expression of virulence determinants. Special attention is paid to integrated control of virulence functions by variations in the superhelical density of chromosomal DNA, and the global and specific regulators, making the regulation of Dickeya virulence an especially attractive model for those interested in relationships between the chromosomal dynamics and gene regulatory networks.
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Affiliation(s)
- S Reverchon
- Department of Biology, University of Lyon, INSA-Lyon, Villeurbanne, Lyon, France.
| | - G Muskhelisvili
- Department of Biology, University of Lyon, INSA-Lyon, Villeurbanne, Lyon, France
| | - W Nasser
- Department of Biology, University of Lyon, INSA-Lyon, Villeurbanne, Lyon, France
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36
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Yuan X, Khokhani D, Wu X, Yang F, Biener G, Koestler BJ, Raicu V, He C, Waters CM, Sundin GW, Tian F, Yang CH. Cross-talk between a regulatory small RNA, cyclic-di-GMP signalling and flagellar regulator FlhDC for virulence and bacterial behaviours. Environ Microbiol 2015; 17:4745-63. [PMID: 26462993 DOI: 10.1111/1462-2920.13029] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 08/14/2015] [Accepted: 08/15/2015] [Indexed: 12/01/2022]
Abstract
Dickeya dadantii is a globally dispersed phytopathogen which causes diseases on a wide range of host plants. This pathogen utilizes the type III secretion system (T3SS) to suppress host defense responses, and secretes pectate lyase (Pel) to degrade the plant cell wall. Although the regulatory small RNA (sRNA) RsmB, cyclic diguanylate monophosphate (c-di-GMP) and flagellar regulator have been reported to affect the regulation of these two virulence factors or multiple cell behaviours such as motility and biofilm formation, the linkage between these regulatory components that coordinate the cell behaviours remain unclear. Here, we revealed a sophisticated regulatory network that connects the sRNA, c-di-GMP signalling and flagellar master regulator FlhDC. We propose multi-tiered regulatory mechanisms that link the FlhDC to the T3SS through three distinct pathways including the FlhDC-FliA-YcgR3937 pathway; the FlhDC-EcpC-RpoN-HrpL pathway; and the FlhDC-rsmB-RsmA-HrpL pathway. Among these, EcpC is the most dominant factor for FlhDC to positively regulate T3SS expression.
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Affiliation(s)
- Xiaochen Yuan
- Department of Biological Sciences, University of Wisconsin, Milwaukee, WI, 53211, USA
| | - Devanshi Khokhani
- Department of Biological Sciences, University of Wisconsin, Milwaukee, WI, 53211, USA
| | - Xiaogang Wu
- Department of Biological Sciences, University of Wisconsin, Milwaukee, WI, 53211, USA
| | - Fenghuan Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Gabriel Biener
- Department of Physics, University of Wisconsin, Milwaukee, WI, 53211, USA
| | - Benjamin J Koestler
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, 48824, USA
| | - Valerica Raicu
- Department of Biological Sciences, University of Wisconsin, Milwaukee, WI, 53211, USA.,Department of Physics, University of Wisconsin, Milwaukee, WI, 53211, USA
| | - Chenyang He
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Christopher M Waters
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, 48824, USA
| | - George W Sundin
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI, 48824, USA
| | - Fang Tian
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Ching-Hong Yang
- Department of Biological Sciences, University of Wisconsin, Milwaukee, WI, 53211, USA
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Arrebola E, Carrión VJ, Gutiérrez-Barranquero JA, Pérez-García A, Rodríguez-Palenzuela P, Cazorla FM, de Vicente A. Cellulose production inPseudomonas syringaepv.syringae: a compromise between epiphytic and pathogenic lifestyles. FEMS Microbiol Ecol 2015; 91:fiv071. [DOI: 10.1093/femsec/fiv071] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/20/2015] [Indexed: 01/11/2023] Open
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Römling U, Galperin MY. Bacterial cellulose biosynthesis: diversity of operons, subunits, products, and functions. Trends Microbiol 2015; 23:545-57. [PMID: 26077867 DOI: 10.1016/j.tim.2015.05.005] [Citation(s) in RCA: 310] [Impact Index Per Article: 34.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 05/05/2015] [Accepted: 05/18/2015] [Indexed: 12/30/2022]
Abstract
Recent studies of bacterial cellulose biosynthesis, including structural characterization of a functional cellulose synthase complex, provided the first mechanistic insight into this fascinating process. In most studied bacteria, just two subunits, BcsA and BcsB, are necessary and sufficient for the formation of the polysaccharide chain in vitro. Other subunits - which differ among various taxa - affect the enzymatic activity and product yield in vivo by modulating (i) the expression of the biosynthesis apparatus, (ii) the export of the nascent β-D-glucan polymer to the cell surface, and (iii) the organization of cellulose fibers into a higher-order structure. These auxiliary subunits play key roles in determining the quantity and structure of resulting biofilms, which is particularly important for the interactions of bacteria with higher organisms - leading to rhizosphere colonization and modulating the virulence of cellulose-producing bacterial pathogens inside and outside of host cells. We review the organization of four principal types of cellulose synthase operon found in various bacterial genomes, identify additional bcs genes that encode components of the cellulose biosynthesis and secretion machinery, and propose a unified nomenclature for these genes and subunits. We also discuss the role of cellulose as a key component of biofilms and in the choice between acute infection and persistence in the host.
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Affiliation(s)
- Ute Römling
- Department of Microbiology, Tumor and Cell Biology (MTC), Karolinska Institutet, Stockholm, Sweden.
| | - Michael Y Galperin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA.
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Lahesaare A, Moor H, Kivisaar M, Teras R. Pseudomonas putida Fis binds to the lapF promoter in vitro and represses the expression of LapF. PLoS One 2014; 9:e115901. [PMID: 25545773 PMCID: PMC4278767 DOI: 10.1371/journal.pone.0115901] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 12/02/2014] [Indexed: 11/19/2022] Open
Abstract
The biofilm matrix of the rhizospheric bacterium Pseudomonas putida consists mainly of a proteinaceous component. The two largest P. putida proteins, adhesins LapA and LapF, are involved in biofilm development but prevail in different developmental stages of the biofilm matrix. LapA is abundant in the initial stage of biofilm formation whereas LapF is found in the mature biofilm. Although the transcriptional regulation of the adhesins is not exhaustively studied, some factors that can be involved in their regulation have been described. For example, RpoS, the major stress response sigma factor, activates, and Fis represses LapF expression. This study focused on the LapF expression control by Fis. Indeed, using DNase I footprint analysis a Fis binding site Fis-F2 was located 150 bp upstream of the lapF gene coding sequence. The mapped 5' end of the lapF mRNA localized the promoter to the same region, overlapping with the Fis binding site Fis-F2. Monitoring the lapF promoter activity by a β-galactosidase assay revealed that Fis overexpression causes a 4-fold decrease in the transcriptional activity. Furthermore, mutations that diminished Fis binding to the Fis-F2 site abolished the repression of the lapF promoter. Thus, these data suggest that Fis is involved in the biofilm regulation via repression of LapF expression.
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Affiliation(s)
- Andrio Lahesaare
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Hanna Moor
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Maia Kivisaar
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Riho Teras
- Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
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Moor H, Teppo A, Lahesaare A, Kivisaar M, Teras R. Fis overexpression enhances Pseudomonas putida biofilm formation by regulating the ratio of LapA and LapF. MICROBIOLOGY-SGM 2014; 160:2681-2693. [PMID: 25253613 DOI: 10.1099/mic.0.082503-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Bacteria form biofilm as a response to a number of environmental signals that are mediated by global transcription regulators and alarmones. Here we report the involvement of the global transcription regulator Fis in Pseudomonas putida biofilm formation through regulation of lapA and lapF genes. The major component of P. putida biofilm is proteinaceous and two large adhesive proteins, LapA and LapF, are known to play a key role in its formation. We have previously shown that Fis overexpression enhances P. putida biofilm formation. In this study, we used mini-Tn5 transposon mutagenesis to select potential Fis-regulated genes involved in biofilm formation. A total of 90 % of the studied transposon mutants carried insertions in the lap genes. Since our experiments showed that Fis-enhanced biofilm is mostly proteinaceous, the amounts of LapA and LapF from P. putida cells lysates were quantified using SDS-PAGE. Fis overexpression increases the quantity of LapA 1.6 times and decreases the amount of LapF at least 4 times compared to the wild-type cells. The increased LapA expression caused by Fis overexpression was confirmed by FACS analysis measuring the amount of LapA-GFP fusion protein. Our results suggest that the profusion of LapA in the Fis-overexpressed cells causes enhanced biofilm formation in mature stages of P. putida biofilm and LapF has a minor role in P. putida biofilm formation.
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Affiliation(s)
- Hanna Moor
- Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia
| | - Annika Teppo
- Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia
| | - Andrio Lahesaare
- Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia
| | - Maia Kivisaar
- Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia
| | - Riho Teras
- Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia
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41
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Duprey A, Reverchon S, Nasser W. Bacterial virulence and Fis: adapting regulatory networks to the host environment. Trends Microbiol 2013; 22:92-9. [PMID: 24370464 DOI: 10.1016/j.tim.2013.11.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 11/21/2013] [Accepted: 11/26/2013] [Indexed: 11/18/2022]
Abstract
Pathogenic bacteria have to cope with adverse conditions, such as the host environment and host defense reactions. To adapt quickly to environmental changes, pathogens have developed complex regulatory networks that ensure adequate expression of their virulence genes. Recent evidence suggests that Fis, an abundant nucleoid-associated protein transiently produced during early exponential growth, plays a major role in these networks in several pathogenic bacteria. This review focuses on two enterobacteria, Salmonella enterica and Dickeya dadantii, that inhabit distinct ecological niches to illustrate how Fis uses different strategies to coordinate virulence gene expression, depending on the bacterial lifestyle.
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Affiliation(s)
- Alexandre Duprey
- Université Lyon 1, F-69622 Villeurbanne, France; INSA de Lyon, F-69621 Villeurbanne, France; CNRS UMR5240 Microbiologie, Adaptation et Pathogénie, Villeurbanne, France
| | - Sylvie Reverchon
- Université Lyon 1, F-69622 Villeurbanne, France; INSA de Lyon, F-69621 Villeurbanne, France; CNRS UMR5240 Microbiologie, Adaptation et Pathogénie, Villeurbanne, France
| | - William Nasser
- Université Lyon 1, F-69622 Villeurbanne, France; INSA de Lyon, F-69621 Villeurbanne, France; CNRS UMR5240 Microbiologie, Adaptation et Pathogénie, Villeurbanne, France.
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Reverchon S, Nasser W. Dickeya ecology, environment sensing and regulation of virulence programme. ENVIRONMENTAL MICROBIOLOGY REPORTS 2013; 5:622-36. [PMID: 24115612 DOI: 10.1111/1758-2229.12073] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 05/25/2013] [Accepted: 05/27/2013] [Indexed: 05/05/2023]
Abstract
The pectinolytic Dickeya spp. are soft-rot Gram-negative bacteria that cause severe disease in a wide range of plant species. In recent years, there has been an increase in the damage caused by Dickeya in potato crops in Europe. Soft-rot symptoms are due to the production and secretion of degradative enzymes that destroy the plant cell wall. However, an efficient colonization of the host plant requires many additional bacterial factors, including elements in the early stages allowing for the adhesion and penetration of the bacteria in the plant and different elements in the intermediate stages, involved in the adaptation to the new growth conditions encountered in the host. Dickeya pathogenicity is clearly a multifactorial process, and successful infection by these bacteria requires a temporal coordination of survival and virulence gene expression. This involves the ancestral nucleoid-associated proteins, Fis and H-NS, and modifications of DNA topology, as well as various specific regulatory systems, including a new quorum-sensing pathway and regulators that sense the bacterial metabolic status or environmental stresses. This review presents new information concerning the ecology of Dickeya and the strategies used by this bacterium to coordinate its survival and virulence programmes during infection.
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Lee DH, Lim JA, Lee J, Roh E, Jung K, Choi M, Oh C, Ryu S, Yun J, Heu S. Characterization of genes required for the pathogenicity of Pectobacterium carotovorum subsp. carotovorum Pcc21 in Chinese cabbage. MICROBIOLOGY-SGM 2013; 159:1487-1496. [PMID: 23676432 PMCID: PMC3749726 DOI: 10.1099/mic.0.067280-0] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Pectobacterium carotovorum subsp. carotovorum is a well-known plant pathogen that causes severe soft rot disease in various crops, resulting in considerable economic loss. To identify pathogenicity-related factors, Chinese cabbage was inoculated with 5314 transposon mutants of P. carotovorum subsp. carotovorum Pcc21 derived using Tn5 transposon mutagenesis. A total of 35 reduced-virulence or avirulent mutants were isolated, and 14 loci were identified. The 14 loci could be functionally grouped into nutrient utilization (pyrD, purH, purD, leuA and serB), production of plant cell-wall-degrading enzymes (PCWDEs) (expI, expR and PCC21_023220), motility (flgA, fliA and flhB), biofilm formation (expI, expR and qseC), susceptibility to antibacterial plant chemicals (tolC) and unknown function (ECA2640). Among the 14 genes identified, qseC, tolC and PCC21_023220 are novel pathogenicity factors of P. carotovorum subsp. carotovorum involved in biofilm formation, phytochemical resistance and PCWDE production, respectively.
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Affiliation(s)
- Dong Hwan Lee
- Division of Microbial Safety, National Academy of Agricultural Science, Rural Development Administration, Suwon 441-707, Republic of Korea
| | - Jeong-A Lim
- Division of Microbial Safety, National Academy of Agricultural Science, Rural Development Administration, Suwon 441-707, Republic of Korea
| | - Juneok Lee
- Division of Microbial Safety, National Academy of Agricultural Science, Rural Development Administration, Suwon 441-707, Republic of Korea
| | - Eunjung Roh
- Division of Microbial Safety, National Academy of Agricultural Science, Rural Development Administration, Suwon 441-707, Republic of Korea
| | - Kyusuk Jung
- Division of Microbial Safety, National Academy of Agricultural Science, Rural Development Administration, Suwon 441-707, Republic of Korea
| | - Minseon Choi
- Department of Horticultural Biotechnology and Institute of Life Science & Resources, Kyung Hee University, Yongin 441-701, Republic of Korea
| | - Changsik Oh
- Department of Horticultural Biotechnology and Institute of Life Science & Resources, Kyung Hee University, Yongin 441-701, Republic of Korea
| | - Sangryeol Ryu
- Department of Agricultural Biotechnology, Center for Agricultural Biomaterials, Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Republic of Korea
| | - Jongchul Yun
- Division of Microbial Safety, National Academy of Agricultural Science, Rural Development Administration, Suwon 441-707, Republic of Korea
| | - Sunggi Heu
- Division of Microbial Safety, National Academy of Agricultural Science, Rural Development Administration, Suwon 441-707, Republic of Korea
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Regulation of lipid biosynthesis, sliding motility, and biofilm formation by a membrane-anchored nucleoid-associated protein of Mycobacterium tuberculosis. J Bacteriol 2013; 195:1769-78. [PMID: 23396914 DOI: 10.1128/jb.02081-12] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Bacteria use a number of small basic proteins for organization and compaction of their genomes. By their interaction with DNA, these nucleoid-associated proteins (NAPs) also influence gene expression. Rv3852, a NAP of Mycobacterium tuberculosis, is conserved among the pathogenic and slow-growing species of mycobacteria. Here, we show that the protein predominantly localizes in the cell membrane and that the carboxy-terminal region with the propensity to form a transmembrane helix is necessary for its membrane localization. The protein is involved in genome organization, and its ectopic expression in Mycobacterium smegmatis resulted in altered nucleoid morphology, defects in biofilm formation, sliding motility, and change in apolar lipid profile. We demonstrate its crucial role in regulating the expression of KasA, KasB, and GroEL1 proteins, which are in turn involved in controlling the surface phenotypes in mycobacteria.
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45
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Coordinated cyclic-di-GMP repression of Salmonella motility through YcgR and cellulose. J Bacteriol 2012; 195:417-28. [PMID: 23161026 DOI: 10.1128/jb.01789-12] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Cyclic di-GMP (c-di-GMP) is a secondary messenger that controls a variety of cellular processes, including the switch between a biofilm and a planktonic bacterial lifestyle. This nucleotide binds to cellular effectors in order to exert its regulatory functions. In Salmonella, two proteins, BcsA and YcgR, both of them containing a c-di-GMP binding PilZ domain, are the only known c-di-GMP receptors. BcsA, upon c-di-GMP binding, synthesizes cellulose, the main exopolysaccharide of the biofilm matrix. YcgR is dedicated to c-di-GMP-dependent inhibition of motility through its interaction with flagellar motor proteins. However, previous evidences indicate that in the absence of YcgR, there is still an additional element that mediates motility impairment under high c-di-GMP levels. Here we have uncovered that cellulose per se is the factor that further promotes inhibition of bacterial motility once high c-di-GMP contents drive the activation of a sessile lifestyle. Inactivation of different genes of the bcsABZC operon, mutation of the conserved residues in the RxxxR motif of the BcsA PilZ domain, or degradation of the cellulose produced by BcsA rescued the motility defect of ΔycgR strains in which high c-di-GMP levels were reached through the overexpression of diguanylate cyclases. High c-di-GMP levels provoked cellulose accumulation around cells that impeded flagellar rotation, probably by means of steric hindrance, without affecting flagellum gene expression, exportation, or assembly. Our results highlight the relevance of cellulose in Salmonella lifestyle switching as an architectural element that is both essential for biofilm development and required, in collaboration with YcgR, for complete motility inhibition.
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