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Macharoen P, Mhuantong W, Wannawong T, Leesutthiphonchai W, Tanasupawat S, Suwannarach N, Kuncharoen N. Bacterial diversity, community structure and function in association of potato scabby tubers during storage in northern Thailand. Folia Microbiol (Praha) 2024; 69:941-952. [PMID: 38315309 DOI: 10.1007/s12223-024-01140-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 01/20/2024] [Indexed: 02/07/2024]
Abstract
Potato scab is a common potato tuber disease that affects quality and cost in the marketplace, shortening storage, and increasing the chance for secondary infection. The tubers with disease severity of 1 to 4 are accepted and stored in potato storage for cheap selling in Thailand. However, there are few studies of the bacterial community of the scabby tuber during storage. Thus, we aim to elucidate the diversity, structure, and function of the bacterial community of 30-day storage potato scabby tubers stored in different temperatures using 16S amplicon metagenomic sequencing. Bacterial communities of storage potato scabby tubers (Spunta cultivar) collected from different storage temperatures, 4 °C (MEP1) and 6 °C (MEP2), were characterized using 16S rRNA amplicon metagenomic sequencing. The alpha-diversity abundance in the bacteriome of the scabby tubers stored at 6 °C was higher than in those stored at 4 °C. Actinobacteria (34.7%) was a dominant phylum in MEP1, while Proteobacteria (39.9%) was predominant in MEP2. The top 10 genera of both communities were Rhizobium group, Streptomyces, Pectobacterium, Ruminococcus, Cellulomonas, Promicromonospora, Prevotella, Enterobacter, Pedobacter, and Paenarthrobacter. Moreover, functional profile prediction of both communities reveals essential genes in the pathosystem: nos, bglA, and cebEFG-msiK for potato scab disease and phc and peh operons for rot disease. Our findings are the first study to explore details of the bacteriome of the accepted potato scabby tubers for selling during storage in Thailand and strongly indicate that although potatoes were stored at low temperatures, diseases still occur by secondary pathogens.
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Affiliation(s)
- Pipat Macharoen
- Department of Plant Pathology, Faculty of Agriculture, Kasetsart University, Bangkok, 10900, Thailand
| | - Wuttichai Mhuantong
- Food Biotechnology Research Team, Functional Ingredients and Food Innovation Research Group, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathum Thani, 12120, Thailand
- Enzyme Technology Research Team, Biorefinery and Bioproducts Technology Research Group, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathum Thani, 12120, Thailand
| | - Thippawan Wannawong
- Department of Plant Pathology, Faculty of Agriculture, Kasetsart University, Bangkok, 10900, Thailand
| | | | - Somboon Tanasupawat
- Department of Biochemistry and Microbiology, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok, 10300, Thailand
| | - Nakarin Suwannarach
- Center Excellence in Microbial Diversity and Sustainable Utilization, Chiang Mai University, Chiang Mai, 50200, Thailand
- Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand
| | - Nattakorn Kuncharoen
- Department of Plant Pathology, Faculty of Agriculture, Kasetsart University, Bangkok, 10900, Thailand.
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Li J, Ma Q, Huang J, Liu Y, Zhou J, Yu S, Zhang Q, Lin Y, Wang L, Zou J, Li Y. Small RNA SmsR1 modulates acidogenicity and cariogenic virulence by affecting protein acetylation in Streptococcus mutans. PLoS Pathog 2024; 20:e1012147. [PMID: 38620039 PMCID: PMC11045139 DOI: 10.1371/journal.ppat.1012147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 04/25/2024] [Accepted: 03/25/2024] [Indexed: 04/17/2024] Open
Abstract
Post-transcriptional regulation by small RNAs and post-translational modifications (PTM) such as lysine acetylation play fundamental roles in physiological circuits, offering rapid responses to environmental signals with low energy consumption. Yet, the interplay between these regulatory systems remains underexplored. Here, we unveil the cross-talk between sRNAs and lysine acetylation in Streptococcus mutans, a primary cariogenic pathogen known for its potent acidogenic virulence. Through systematic overexpression of sRNAs in S. mutans, we identified sRNA SmsR1 as a critical player in modulating acidogenicity, a key cariogenic virulence feature in S. mutans. Furthermore, combined with the analysis of predicted target mRNA and transcriptome results, potential target genes were identified and experimentally verified. A direct interaction between SmsR1 and 5'-UTR region of pdhC gene was determined by in vitro binding assays. Importantly, we found that overexpression of SmsR1 reduced the expression of pdhC mRNA and increased the intracellular concentration of acetyl-CoA, resulting in global changes in protein acetylation levels. This was verified by acetyl-proteomics in S. mutans, along with an increase in acetylation level and decreased activity of LDH. Our study unravels a novel regulatory paradigm where sRNA bridges post-transcriptional regulation with post-translational modification, underscoring bacterial adeptness in fine-tuning responses to environmental stress.
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Affiliation(s)
- Jing Li
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
- Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Qizhao Ma
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
- Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jun Huang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
- Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yaqi Liu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
- Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jing Zhou
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
- Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Shuxing Yu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
- Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Qiong Zhang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
- Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yongwang Lin
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
- Department of Operative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Lingyun Wang
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Jing Zou
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
- Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yuqing Li
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
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Kang J, Yoon HM, Jung J, Yu S, Choi SY, Bae HW, Cho YH, Chung EH, Lee Y. Pleiotropic effects of N-acylhomoserine lactone synthase ExpI on virulence, competition, and transmission in Pectobacterium carotovorum subsp. carotovorum Pcc21. PEST MANAGEMENT SCIENCE 2024; 80:687-697. [PMID: 37758685 DOI: 10.1002/ps.7797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/18/2023] [Accepted: 09/28/2023] [Indexed: 09/29/2023]
Abstract
BACKGROUND Pectobacterium species are necrotrophic phytopathogenic bacteria that cause soft rot disease in economically important crops. The successful infection of host plants relies on interactions among virulence factors, competition, and transmission within hosts. Pectobacteria primarily produce and secrete plant cell-wall degrading enzymes (PCWDEs) for virulence. The regulation of PCWDEs is controlled by quorum sensing (QS). Thus, the QS system is crucial for disease development in pectobacteria through PCWDEs. RESULTS In this study, we identified a Tn-insertion mutant, M2, in the expI gene from a transposon mutant library of P. carotovorum subsp. carotovorum Pcc21 (hereafter Pcc21). The mutant exhibited reduced production and secretion of PCWDEs, impaired flagellar motility, and increased sensitivity to hydrogen peroxide, resulting in attenuated soft rot symptoms in cabbage and potato tubers. Transcriptomic analysis revealed the down-regulation of genes involved in the production and secretion in the mutant, consistent with the observed phenotype. Furthermore, the Pcc21 wild-type transiently colonized in the gut of Drosophila melanogaster within 12 h after feeding, while the mutant compromised colonization phenotype. Interestingly, Pcc21 produces a bacteriocin, carocin D, to compete with other bacteria. The mutant exhibited up-regulation of carocin D-encoding genes (caroDK) and inhibited the growth of a closely related bacterium, P. wasabiae. CONCLUSION Our results demonstrated the significance of ExpI in the overall pathogenic lifestyle of Pcc21, including virulence, competition, and colonization in plant and insect hosts. These findings suggest that disease outcome is a result of complex interactions mediated by ExpI across multiple steps. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Jihee Kang
- Department of Food Science and Biotechnology, CHA University, Pocheon, Republic of Korea
| | - Hye Min Yoon
- Department of Food Science and Biotechnology, CHA University, Pocheon, Republic of Korea
| | - Jaejoon Jung
- Department of Life Science, Chung-Ang University, Seoul, Republic of Korea
| | - Seonmi Yu
- Department of Food Science and Biotechnology, CHA University, Pocheon, Republic of Korea
| | - Shin-Yae Choi
- Department of Pharmacy, and Institutes of Pharmaceutical Sciences, CHA University, Seongnam, Republic of Korea
| | - Hee-Won Bae
- Department of Life Science, Chung-Ang University, Seoul, Republic of Korea
| | - You-Hee Cho
- Department of Pharmacy, and Institutes of Pharmaceutical Sciences, CHA University, Seongnam, Republic of Korea
| | - Eui-Hwan Chung
- Department of Plant Biotechnology, Korea University, Seoul, Republic of Korea
| | - Yunho Lee
- Department of Food Science and Biotechnology, CHA University, Pocheon, Republic of Korea
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Chen C, Che S, Dong Z, Sui J, Tian Y, Su Y, Zhang M, Sun W, Fan J, Xie J, Xie H. A genome-wide association study reveals that epistasis underlies the pathogenicity of Pectobacterium. Microbiol Spectr 2023; 11:e0176423. [PMID: 37712699 PMCID: PMC10580964 DOI: 10.1128/spectrum.01764-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 07/28/2023] [Indexed: 09/16/2023] Open
Abstract
Pectobacterium spp. are important bacterial pathogens that cause soft rot symptoms in various crops. However, their mechanism of pathogenicity requires clarity to help control their infections. Here, genome-wide association studies (GWAS) were conducted by integrating genomic data and measurements of two phenotypes (virulence and cellulase activity) for 120 various Pectobacterium strains in order to identify the genetic basis of their pathogenicity. An artificial intelligence-based software program was developed to automatically measure lesion areas on Chinese cabbage, thereby facilitating accurate and rapid data collection for virulence phenotypes for use in GWAS analysis. The analysis discovered 428 and 158 loci significantly associated with Pectobacterium virulence (lesion area) and cellulase activity, respectively. In addition, 1,229 and 586 epistasis loci pairs were identified for the virulence and cellulase activity phenotypes, respectively. Among them, the AraC transcriptional regulator exerted epistasis effects with another three nutrient transport-related genes in pairs contributing to the virulence phenotype, and their epistatic effects were experimentally confirmed for one pair with knockout mutants of each single gene and double gene. This study consequently provides valuable insights into the genetic mechanism underlying Pectobacterium spp. pathogenicity. IMPORTANCE Plant diseases and pests are responsible for the loss of up to 40% of food crops, and annual economic losses caused by plant diseases reach more than $220 billion. Fighting against plant diseases requires an understanding of the pathogenic mechanisms of pathogens. This study adopted an advanced approach using population genomics integrated with virulence-related phenotype data to investigate the genetic basis of Pectobacterium spp., which causes serious crop losses worldwide. An automated software program based on artificial intelligence was developed to measure the virulence phenotype (lesion area), which greatly facilitated this research. The analysis predicted key genomic loci that were highly associated with virulence phenotypes, exhibited epistasis effects, and were further confirmed as critical for virulence with mutant gene deletion experiments. The present study provides new insights into the genetic determinants associated with Pectobacterium pathogenicity and provides a valuable new software resource that can be adapted to improve plant infection measurements.
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Affiliation(s)
- Changlong Chen
- Institute of Biotechnology, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Shu Che
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Zhou Dong
- EVision Technology (Beijing) Co. Ltd, Beijing, China
| | - Jiayi Sui
- Institute of Biotechnology, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Yu Tian
- Institute of Biotechnology, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Yanyan Su
- Institute of Biotechnology, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Meng Zhang
- Institute of Biotechnology, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Wangwang Sun
- Institute of Biotechnology, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Jiaqin Fan
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Jianbo Xie
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Hua Xie
- Institute of Biotechnology, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
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Anderson JC. Ill Communication: Host Metabolites as Virulence-Regulating Signals for Plant-Pathogenic Bacteria. ANNUAL REVIEW OF PHYTOPATHOLOGY 2023; 61:49-71. [PMID: 37253693 DOI: 10.1146/annurev-phyto-021621-114026] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Plant bacterial pathogens rely on host-derived signals to coordinate the deployment of virulence factors required for infection. In this review, I describe how diverse plant-pathogenic bacteria detect and respond to plant-derived metabolic signals for the purpose of virulence gene regulation. I highlight examples of how pathogens perceive host metabolites through membrane-localized receptors as well as intracellular response mechanisms. Furthermore, I describe how individual strains may coordinate their virulence using multiple distinct host metabolic signals, and how plant signals may positively or negatively regulate virulence responses. I also describe how plant defenses may interfere with the perception of host metabolites as a means to dampen pathogen virulence. The emerging picture is that recognition of host metabolic signals for the purpose of virulence gene regulation represents an important primary layer of interaction between pathogenic bacteria and host plants that shapes infection outcomes.
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Affiliation(s)
- Jeffrey C Anderson
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, USA;
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Li R, Peng J, Liu Q, Chang Z, Huang Y, Tang J, Lu G. Xanthomonas campestris VemR enhances the transcription of the T3SS key regulator HrpX via physical interaction with HrpG. MOLECULAR PLANT PATHOLOGY 2023; 24:232-247. [PMID: 36626275 PMCID: PMC9923393 DOI: 10.1111/mpp.13293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 11/28/2022] [Accepted: 12/09/2022] [Indexed: 06/17/2023]
Abstract
VemR is a response regulator of the two-component signalling systems (TCSs). It consists solely of a receiver domain. Previous studies have shown that VemR plays an important role in influencing the production of exopolysaccharides and exoenzymes, cell motility, and virulence of Xanthomonas campestris pv. campestris (Xcc). However, whether VemR is involved in the essential pathogenicity determinant type III secretion system (T3SS) is unclear. In this work, we found by transcriptome analysis that VemR modulates about 10% of Xcc genes, which are involved in various cellular processes including the T3SS. Further experiments revealed that VemR physically interacts with numerous proteins, including the TCS sensor kinases HpaS and RavA, and the TCS response regulator HrpG, which directly activates the transcription of HrpX, a key regulator controlling T3SS expression. It has been demonstrated previously that HpaS composes a TCS with HrpG or VemR to control the expression of T3SS or swimming motility, while RavA and VemR form a TCS to control the expression of flagellar genes. Mutation analysis and in vitro transcription assay revealed that phosphorylation might be essential for the function of VemR and phosphorylated VemR could significantly enhance the activation of hrpX transcription by HrpG. We infer that the binding of VemR to HrpG can modulate the activity of HrpG to the hrpX promoter, thereby enhancing hrpX transcription. Although further studies are required to validate this inference and explore the detailed functional mechanism of VemR, our findings provide some insights into the complex regulatory cascade of the HpaS/RavA-VemR/HrpG-HrpX signal transduction system in the control of T3SS.
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Affiliation(s)
- Rui‐Fang Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesCollege of Life Science and Technology, Guangxi UniversityNanningChina
- Guangxi Key Laboratory of Biology for Crop Diseases and Insect PestsPlant Protection Research Institute, Guangxi Academy of Agricultural SciencesNanningChina
| | - Jian‐Ling Peng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesCollege of Life Science and Technology, Guangxi UniversityNanningChina
| | - Qian‐Qian Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesCollege of Life Science and Technology, Guangxi UniversityNanningChina
| | - Zheng Chang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesCollege of Life Science and Technology, Guangxi UniversityNanningChina
| | - Yi‐Xin Huang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesCollege of Life Science and Technology, Guangxi UniversityNanningChina
| | - Ji‐Liang Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesCollege of Life Science and Technology, Guangxi UniversityNanningChina
| | - Guang‐Tao Lu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro‐BioresourcesCollege of Life Science and Technology, Guangxi UniversityNanningChina
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Yu S, Kang J, Chung EH, Lee Y. Disruption of the metC Gene Affects Methionine Biosynthesis in Pectobacterium carotovorum subsp. carotovorum Pcc21 and Reduces Soft-Rot Disease. THE PLANT PATHOLOGY JOURNAL 2023; 39:62-74. [PMID: 36760050 PMCID: PMC9929172 DOI: 10.5423/ppj.oa.09.2022.0135] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 11/28/2022] [Accepted: 11/28/2022] [Indexed: 06/18/2023]
Abstract
Plant pathogenic Pectobacterium species cause severe soft rot/blackleg diseases in many economically important crops worldwide. Pectobacterium utilizes plant cell wall degrading enzymes (PCWDEs) as the main virulence determinants for its pathogenicity. In this study, we screened a random mutant, M29 is a transposon insertion mutation in the metC gene encoding cystathionine β-lyase that catalyzes cystathionine to homocysteine at the penultimate step in methionine biosynthesis. M29 became a methionine auxotroph and resulted in growth defects in methionine-limited conditions. Impaired growth was restored with exogenous methionine or homocysteine rather than cystathionine. The mutant exhibited reduced soft rot symptoms in Chinese cabbages and potato tubers, maintaining activities of PCWDEs and swimming motility. The mutant was unable to proliferate in both Chinese cabbages and potato tubers. The reduced virulence was partially restored by a complemented strain or 100 µM of methionine, whereas it was fully restored by the extremely high concentration (1 mM). Our transcriptomic analysis showed that genes involved in methionine biosynthesis or transporter were downregulated in the mutant. Our results demonstrate that MetC is important for methionine biosynthesis and transporter and influences its virulence through Pcc21 multiplication in plant hosts.
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Affiliation(s)
- Seonmi Yu
- Department of Food Science and Biotechnology, CHA University, Pocheon 11160,
Korea
| | - Jihee Kang
- Department of Food Science and Biotechnology, CHA University, Pocheon 11160,
Korea
| | - Eui-Hwan Chung
- Department of Plant Biotechnology, Korea University, Seoul 02841,
Korea
| | - Yunho Lee
- Department of Food Science and Biotechnology, CHA University, Pocheon 11160,
Korea
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Xu Z, Wu G, Wang B, Zhao Y, Liu F. TrpR-Like Protein PXO_00831, Regulated by the Sigma Factor RpoD, Is Involved in Motility, Oxidative Stress Tolerance, and Virulence in Xanthomonas oryzae pv. oryzae. PHYTOPATHOLOGY 2023; 113:170-182. [PMID: 36095334 DOI: 10.1094/phyto-05-22-0165-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Xanthomonas oryzae pv. oryzae (Xoo) is a Gram-negative bacterium that causes bacterial leaf blight in rice. In this study, we identified a putative TrpR-like protein, PXO_TrpR (PXO_00831), in Xoo. This protein contains a tryptophan (Trp) repressor domain and is highly conserved in Xanthomonas. Auxotrophic assays and RT-qPCR confirmed that PXO_TrpR acts as a Trp repressor, negatively regulating the expression of Trp biosynthesis genes. Pathogenicity tests showed that PXO_trpR knockout in Xoo significantly reduced lesion development and disease symptoms in the leaves of susceptible rice. RNA-seq analysis and phenotypic tests revealed that the PXO_trpR mutant exhibited impaired cell motility and was more sensitive to H2O2 oxidative stress than the wild-type strain. Furthermore, we found that the sigma 70 factor RpoD controlled the transcription of PXO_trpR by directly binding to its promoter region. This study demonstrates the biological function and transcriptional mechanism of PXO_TrpR as a Trp repressor in Xoo and evaluates its novel pathogenic roles by regulating flagellar motility and the oxidative stress response.
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Affiliation(s)
- Zhizhou Xu
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Guichun Wu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, Jiangsu 210014, China
- National Engineering Laboratory of Crop Stress Resistance Breeding, School of Life Sciences, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Bo Wang
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, Jiangsu 210014, China
| | - Yancun Zhao
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, Jiangsu 210014, China
| | - Fengquan Liu
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Nanjing, Jiangsu 210014, China
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Falà AK, Álvarez-Ordóñez A, Filloux A, Gahan CGM, Cotter PD. Quorum sensing in human gut and food microbiomes: Significance and potential for therapeutic targeting. Front Microbiol 2022; 13:1002185. [PMID: 36504831 PMCID: PMC9733432 DOI: 10.3389/fmicb.2022.1002185] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Accepted: 10/17/2022] [Indexed: 11/27/2022] Open
Abstract
Human gut and food microbiomes interact during digestion. The outcome of these interactions influences the taxonomical composition and functional capacity of the resident human gut microbiome, with potential consequential impacts on health and disease. Microbe-microbe interactions between the resident and introduced microbiomes, which likely influence host colonisation, are orchestrated by environmental conditions, elements of the food matrix, host-associated factors as well as social cues from other microorganisms. Quorum sensing is one example of a social cue that allows bacterial communities to regulate genetic expression based on their respective population density and has emerged as an attractive target for therapeutic intervention. By interfering with bacterial quorum sensing, for instance, enzymatic degradation of signalling molecules (quorum quenching) or the application of quorum sensing inhibitory compounds, it may be possible to modulate the microbial composition of communities of interest without incurring negative effects associated with traditional antimicrobial approaches. In this review, we summarise and critically discuss the literature relating to quorum sensing from the perspective of the interactions between the food and human gut microbiome, providing a general overview of the current understanding of the prevalence and influence of quorum sensing in this context, and assessing the potential for therapeutic targeting of quorum sensing mechanisms.
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Affiliation(s)
- A. Kate Falà
- APC Microbiome Ireland, University College Cork, Cork, Ireland,School of Microbiology, University College Cork, Cork, Ireland,Food Bioscience Department, Teagasc Food Research Centre, Fermoy, Ireland
| | - Avelino Álvarez-Ordóñez
- Department of Food Hygiene and Technology and Institute of Food Science and Technology, Universidad de León, León, Spain
| | - Alain Filloux
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Cormac G. M. Gahan
- APC Microbiome Ireland, University College Cork, Cork, Ireland,School of Microbiology, University College Cork, Cork, Ireland,School of Pharmacy, University College Cork, Cork, Ireland
| | - Paul D. Cotter
- APC Microbiome Ireland, University College Cork, Cork, Ireland,Food Bioscience Department, Teagasc Food Research Centre, Fermoy, Ireland,*Correspondence: Paul D. Cotter,
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10
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Genomic analysis reveals the role of integrative and conjugative elements in plant pathogenic bacteria. Mob DNA 2022; 13:19. [PMID: 35962419 PMCID: PMC9373382 DOI: 10.1186/s13100-022-00275-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 06/22/2022] [Indexed: 11/29/2022] Open
Abstract
Background ICEs are mobile genetic elements found integrated into bacterial chromosomes that can excise and be transferred to a new cell. They play an important role in horizontal gene transmission and carry accessory genes that may provide interesting phenotypes for the bacteria. Here, we seek to research the presence and the role of ICEs in 300 genomes of phytopathogenic bacteria with the greatest scientific and economic impact. Results Seventy-eight ICEs (45 distinct elements) were identified and characterized in chromosomes of Agrobacterium tumefaciens, Dickeya dadantii, and D. solani, Pectobacterium carotovorum and P. atrosepticum, Pseudomonas syringae, Ralstonia solanacearum Species Complex, and Xanthomonas campestris. Intriguingly, the co-occurrence of four ICEs was observed in some P. syringae strains. Moreover, we identified 31 novel elements, carrying 396 accessory genes with potential influence on virulence and fitness, such as genes coding for functions related to T3SS, cell wall degradation and resistance to heavy metals. We also present the analysis of previously reported data on the expression of cargo genes related to the virulence of P. atrosepticum ICEs, which evidences the role of these genes in the infection process of tobacco plants. Conclusions Altogether, this paper has highlighted the potential of ICEs to affect the pathogenicity and lifestyle of these phytopathogens and direct the spread of significant putative virulence genes in phytopathogenic bacteria. Supplementary Information The online version contains supplementary material available at 10.1186/s13100-022-00275-1.
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Song S, Sun X, Guo Q, Cui B, Zhu Y, Li X, Zhou J, Zhang LH, Deng Y. An anthranilic acid-responsive transcriptional regulator controls the physiology and pathogenicity of Ralstonia solanacearum. PLoS Pathog 2022; 18:e1010562. [PMID: 35617422 PMCID: PMC9176790 DOI: 10.1371/journal.ppat.1010562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 06/08/2022] [Accepted: 04/29/2022] [Indexed: 11/25/2022] Open
Abstract
Quorum sensing (QS) is widely employed by bacterial cells to control gene expression in a cell density-dependent manner. A previous study revealed that anthranilic acid from Ralstonia solanacearum plays a vital role in regulating the physiology and pathogenicity of R. solanacearum. We reported here that anthranilic acid controls the important biological functions and virulence of R. solanacearum through the receptor protein RaaR, which contains helix-turn-helix (HTH) and LysR substrate binding (LysR_substrate) domains. RaaR regulates the same processes as anthranilic acid, and both are present in various bacterial species. In addition, anthranilic acid-deficient mutant phenotypes were rescued by in trans expression of RaaR. Intriguingly, we found that anthranilic acid binds to the LysR_substrate domain of RaaR with high affinity, induces allosteric conformational changes, and then enhances the binding of RaaR to the promoter DNA regions of target genes. These findings indicate that the components of the anthranilic acid signaling system are distinguished from those of the typical QS systems. Together, our work presents a unique and widely conserved signaling system that might be an important new type of cell-to-cell communication system in bacteria. Bacterial wilt caused by Ralstonia solanacearum is one of the most widespread, harmful and destructive plant diseases in the world. Our previous study showed that the pathogenic bacterium R. solanacearum uses anthranilic acid to regulate the important biological functions, virulence and the production of quorum sensing signals. Here, we show that RaaR, a transcriptional regulator from R. solanacearum, was first identified to regulate the same phenotypes as anthranilic acid. Anthranilic acid binds to the LysR_substrate domain of RaaR and enhances the regulatory activity of RaaR to control the target gene expression, including the QS signal synthase encoding genes, phcB and solI. Both the anthranilic acid synthase TrpEG and the response regulator RaaR are present in diverse bacteria, suggesting that the anthranilic acid-type signaling system is widespread. Together, our work describes a system where a pathogen uses a single protein to control the bacterial physiology and pathogenesis by responding to anthranilic acid.
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Affiliation(s)
- Shihao Song
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
- Integrative Microbiology Research Center, College of Plant Protection, South China Agricultural University, Guangzhou, China
| | - Xiuyun Sun
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Quan Guo
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Binbin Cui
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Yu Zhu
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Xia Li
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Jianuan Zhou
- Integrative Microbiology Research Center, College of Plant Protection, South China Agricultural University, Guangzhou, China
| | - Lian-Hui Zhang
- Integrative Microbiology Research Center, College of Plant Protection, South China Agricultural University, Guangzhou, China
| | - Yinyue Deng
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
- * E-mail:
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12
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Ye P, Li X, Cui B, Song S, Shen F, Chen X, Wang G, Zhou X, Deng Y. Proline utilization A controls bacterial pathogenicity by sensing its substrate and cofactors. Commun Biol 2022; 5:496. [PMID: 35614320 PMCID: PMC9132996 DOI: 10.1038/s42003-022-03451-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 05/05/2022] [Indexed: 11/26/2022] Open
Abstract
Previous reports indicate that proline utilization A (PutA) is involved in the oxidation of proline to glutamate in many bacteria. We demonstrate here that in addition to its role in proline catabolism, PutA acts as a global regulator to control the important biological functions and virulence of Ralstonia solanacearum. PutA regulates target gene expression levels by directly binding to promoter DNA, and its regulatory activity is enhanced by L-proline. Intriguingly, we reveal that the cofactors NAD+ and FAD boost the enzymatic activity of PutA for converting L-proline to L-glutamic acid but inhibit the regulatory activity of PutA for controlling target gene expression. Our results present evidence that PutA is a proline metabolic enzyme that also functions as a global transcriptional regulator in response to its substrate and cofactors and provide insights into the complicated regulatory mechanism of PutA in bacterial physiology and pathogenicity.
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Affiliation(s)
- Peiyi Ye
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, 518107, China
- Integrative Microbiology Research Center, College of Plant Protection, South China Agricultural University, Guangzhou, 510642, China
| | - Xia Li
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, 518107, China
| | - Binbin Cui
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, 518107, China
| | - Shihao Song
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, 518107, China
- Integrative Microbiology Research Center, College of Plant Protection, South China Agricultural University, Guangzhou, 510642, China
| | - Fangfang Shen
- Integrative Microbiology Research Center, College of Plant Protection, South China Agricultural University, Guangzhou, 510642, China
| | - Xiayu Chen
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, 518107, China
| | - Gerun Wang
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, 518107, China
| | - Xiaofan Zhou
- Integrative Microbiology Research Center, College of Plant Protection, South China Agricultural University, Guangzhou, 510642, China
| | - Yinyue Deng
- School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, 518107, China.
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13
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Zeiss DR, Steenkamp PA, Piater LA, Dubery IA. Metabolomic Evaluation of Ralstonia solanacearum Cold Shock Protein Peptide (csp22)-Induced Responses in Solanum lycopersicum. FRONTIERS IN PLANT SCIENCE 2022; 12:803104. [PMID: 35069661 PMCID: PMC8780328 DOI: 10.3389/fpls.2021.803104] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 12/13/2021] [Indexed: 06/14/2023]
Abstract
Ralstonia solanacearum, the causal agent of bacterial wilt, is one of the most destructive bacterial plant pathogens. This is linked to its evolutionary adaptation to evade host surveillance during the infection process since many of the pathogen's associated molecular patterns escape recognition. However, a 22-amino acid sequence of R. solanacearum-derived cold shock protein (csp22) was discovered to elicit an immune response in the Solanaceae. Using untargeted metabolomics, the effects of csp22-elicitation on the metabolome of Solanum lycopersicum leaves were investigated. Additionally, the study set out to discover trends that may suggest that csp22 inoculation bestows enhanced resistance on tomato against bacterial wilt. Results revealed the redirection of metabolism toward the phenylpropanoid pathway and sub-branches thereof. Compared to the host response with live bacteria, csp22 induced a subset of the discriminant metabolites, but also metabolites not induced in response to R. solanacearum. Here, a spectrum of hydroxycinnamic acids (especially ferulic acid), their conjugates and derivatives predominated as signatory biomarkers. From a metabolomics perspective, the results support claims that csp22 pre-treatment of tomato plants elicits increased resistance to R. solanacearum infection and contribute to knowledge on plant immune systems operation at an integrative level. The functional significance of these specialized compounds may thus support a heightened state of defense that can be applied to ward off attacking pathogens or toward priming of defense against future infections.
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Zhang ZP, Song SX, Liu YC, Zhu XR, Jiang YF, Shi LT, Jiang JZ, Miao MM. Mixed Transcriptome Analysis Revealed the Possible Interaction Mechanisms between Zizania latifolia and Ustilago esculenta Inducing Jiaobai Stem-Gall Formation. Int J Mol Sci 2021; 22:ijms222212258. [PMID: 34830140 PMCID: PMC8618054 DOI: 10.3390/ijms222212258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 11/06/2021] [Accepted: 11/09/2021] [Indexed: 11/23/2022] Open
Abstract
The smut fungus Ustilago esculenta infects Zizania latifolia and induces stem expansion to form a unique vegetable named Jiaobai. Although previous studies have demonstrated that hormonal control is essential for triggering stem swelling, the role of hormones synthesized by Z. latifolia and U. esculenta and the underlying molecular mechanism are not yet clear. To study the mechanism that triggers swollen stem formation, we analyzed the gene expression pattern of both interacting organisms during the initial trigger of culm gall formation, at which time the infective hyphae also propagated extensively and penetrated host stem cells. Transcriptional analysis indicated that abundant genes involving fungal pathogenicity and plant resistance were reprogrammed to maintain the subtle balance between the parasite and host. In addition, the expression of genes involved in auxin biosynthesis of U. esculenta obviously decreased during stem swelling, while a large number of genes related to the synthesis, metabolism and signal transduction of hormones of the host plant were stimulated and showed specific expression patterns, particularly, the expression of ZlYUCCA9 (a flavin monooxygenase, the key enzyme in indole-3-acetic acid (IAA) biosynthesis pathway) increased significantly. Simultaneously, the content of IAA increased significantly, while the contents of cytokinin and gibberellin showed the opposite trend. We speculated that auxin produced by the host plant, rather than the fungus, triggers stem swelling. Furthermore, from the differently expressed genes, two candidate Cys2-His2 (C2H2) zinc finger proteins, GME3058_g and GME5963_g, were identified from U. esculenta, which may conduct fungus growth and infection at the initial stage of stem-gall formation.
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Affiliation(s)
- Zhi-Ping Zhang
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China; (Z.-P.Z.); (S.-X.S.); (Y.-C.L.); (X.-R.Z.); (Y.-F.J.); (L.-T.S.); (J.-Z.J.)
- Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Agricultural College, Yangzhou University, Yangzhou 225009, China
| | - Si-Xiao Song
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China; (Z.-P.Z.); (S.-X.S.); (Y.-C.L.); (X.-R.Z.); (Y.-F.J.); (L.-T.S.); (J.-Z.J.)
| | - Yan-Cheng Liu
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China; (Z.-P.Z.); (S.-X.S.); (Y.-C.L.); (X.-R.Z.); (Y.-F.J.); (L.-T.S.); (J.-Z.J.)
| | - Xin-Rui Zhu
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China; (Z.-P.Z.); (S.-X.S.); (Y.-C.L.); (X.-R.Z.); (Y.-F.J.); (L.-T.S.); (J.-Z.J.)
| | - Yi-Feng Jiang
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China; (Z.-P.Z.); (S.-X.S.); (Y.-C.L.); (X.-R.Z.); (Y.-F.J.); (L.-T.S.); (J.-Z.J.)
| | - Ling-Tong Shi
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China; (Z.-P.Z.); (S.-X.S.); (Y.-C.L.); (X.-R.Z.); (Y.-F.J.); (L.-T.S.); (J.-Z.J.)
| | - Jie-Zeng Jiang
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China; (Z.-P.Z.); (S.-X.S.); (Y.-C.L.); (X.-R.Z.); (Y.-F.J.); (L.-T.S.); (J.-Z.J.)
| | - Min-Min Miao
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China; (Z.-P.Z.); (S.-X.S.); (Y.-C.L.); (X.-R.Z.); (Y.-F.J.); (L.-T.S.); (J.-Z.J.)
- Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Agricultural College, Yangzhou University, Yangzhou 225009, China
- Correspondence:
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15
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Ali M, Ali Q, Sohail MA, Ashraf MF, Saleem MH, Hussain S, Zhou L. Diversity and Taxonomic Distribution of Endophytic Bacterial Community in the Rice Plant and Its Prospective. Int J Mol Sci 2021; 22:ijms221810165. [PMID: 34576331 PMCID: PMC8465699 DOI: 10.3390/ijms221810165] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 09/06/2021] [Accepted: 09/16/2021] [Indexed: 11/16/2022] Open
Abstract
Endophytic bacterial communities are beneficial communities for host plants that exist inside the surfaces of plant tissues, and their application improves plant growth. They benefit directly from the host plant by enhancing the nutrient amount of the plant’s intake and influencing the phytohormones, which are responsible for growth promotion and stress. Endophytic bacteria play an important role in plant-growth promotion (PGP) by regulating the indirect mechanism targeting pest and pathogens through hydrolytic enzymes, antibiotics, biocontrol potential, and nutrient restriction for pathogens. To attain these benefits, firstly bacterial communities must be colonized by plant tissues. The nature of colonization can be achieved by using a set of traits, including attachment behavior and motility speed, degradation of plant polymers, and plant defense evasion. The diversity of bacterial endophytes colonization depends on various factors, such as plants’ relationship with environmental factors. Generally, each endophytic bacteria has a wide host range, and they are used as bio-inoculants in the form of synthetic applications for sustainable agriculture systems and to protect the environment from chemical hazards. This review discusses and explores the taxonomic distribution of endophytic bacteria associated with different genotypes of rice plants and their origin, movement, and mechanism of PGP. In addition, this review accentuates compressive meta data of endophytic bacteria communities associated with different genotypes of rice plants, retrieves their plant-growth-promoting properties and their antagonism against plant pathogens, and discusses the indication of endophytic bacterial flora in rice plant tissues using various methods. The future direction deepens the study of novel endophytic bacterial communities and their identification from rice plants through innovative techniques and their application for sustainable agriculture systems.
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Affiliation(s)
- Mohsin Ali
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Agro-Product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China;
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Qurban Ali
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
- Correspondence: (Q.A.); (L.Z.)
| | - Muhammad Aamir Sohail
- Center for Excellence in Molecular Plant Sciences, National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China;
| | | | - Muhammad Hamzah Saleem
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China;
| | - Saddam Hussain
- Department of Agronomy, University of Agriculture, Faisalabad 38040, Punjab, Pakistan;
| | - Lei Zhou
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Institute of Agro-Product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China;
- Correspondence: (Q.A.); (L.Z.)
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16
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O’Malley MR, Anderson JC. Regulation of the Pseudomonas syringae Type III Secretion System by Host Environment Signals. Microorganisms 2021; 9:microorganisms9061227. [PMID: 34198761 PMCID: PMC8228185 DOI: 10.3390/microorganisms9061227] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/30/2021] [Accepted: 06/01/2021] [Indexed: 12/12/2022] Open
Abstract
Pseudomonas syringae are Gram-negative, plant pathogenic bacteria that use a type III secretion system (T3SS) to disarm host immune responses and promote bacterial growth within plant tissues. Despite the critical role for type III secretion in promoting virulence, T3SS-encoding genes are not constitutively expressed by P. syringae and must instead be induced during infection. While it has been known for many years that culturing P. syringae in synthetic minimal media can induce the T3SS, relatively little is known about host signals that regulate the deployment of the T3SS during infection. The recent identification of specific plant-derived amino acids and organic acids that induce T3SS-inducing genes in P. syringae has provided new insights into host sensing mechanisms. This review summarizes current knowledge of the regulatory machinery governing T3SS deployment in P. syringae, including master regulators HrpRS and HrpL encoded within the T3SS pathogenicity island, and the environmental factors that modulate the abundance and/or activity of these key regulators. We highlight putative receptors and regulatory networks involved in linking the perception of host signals to the regulation of the core HrpRS–HrpL pathway. Positive and negative regulation of T3SS deployment is also discussed within the context of P. syringae infection, where contributions from distinct host signals and regulatory networks likely enable the fine-tuning of T3SS deployment within host tissues. Last, we propose future research directions necessary to construct a comprehensive model that (a) links the perception of host metabolite signals to T3SS deployment and (b) places these host–pathogen signaling events in the overall context of P. syringae infection.
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Keswani C, Singh SP, Cueto L, García-Estrada C, Mezaache-Aichour S, Glare TR, Borriss R, Singh SP, Blázquez MA, Sansinenea E. Auxins of microbial origin and their use in agriculture. Appl Microbiol Biotechnol 2020; 104:8549-8565. [PMID: 32918584 DOI: 10.1007/s00253-020-10890-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/31/2020] [Accepted: 09/04/2020] [Indexed: 12/13/2022]
Abstract
To maintain the world population demand, a sustainable agriculture is needed. Since current global vision is more friendly with the environment, eco-friendly alternatives are desirable. In this sense, plant growth-promoting rhizobacteria could be the choice for the management of soil-borne diseases of crop plants. These rhizobacteria secrete chemical compounds which act as phytohormones. Indole-3-acetic acid (IAA) is the most common plant hormone of the auxin class which regulates various processes of plant growth. IAA compound, in which structure can be found a carboxylic acid attached through a methylene group to the C-3 position of an indole ring, is produced both by plants and microorganisms. Plant growth-promoting rhizobacteria and fungi secrete IAA to promote the plant growth. In this review, IAA production and mechanisms of action by bacteria and fungi along with the metabolic pathways evolved in the IAA secretion and commercial prospects are revised.Key points• Many microorganisms produce auxins which help the plant growth promotion.• These auxins improve the plant growth by several mechanisms.• The auxins are produced through different mechanisms.
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Affiliation(s)
- Chetan Keswani
- Department of Biochemistry, Faculty of Science, Banaras Hindu University, Varanasi, India
| | - Satyendra Pratap Singh
- Department of Mycology and Plant Pathology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, India
| | - Laura Cueto
- Instituto de Biotecnología de León (INBIOTEC), Parque Científico de León, Av, Real, 1, 24006, León, Spain
| | - Carlos García-Estrada
- Instituto de Biotecnología de León (INBIOTEC), Parque Científico de León, Av, Real, 1, 24006, León, Spain.,Departamento de Ciencias Biomédicas, Universidad de León, Campus de Vegazana s/n, 24071, León, Spain
| | | | - Travis R Glare
- Bio-Protection Research Centre, Lincoln University, PO Box 85084, Lincoln, 7647, New Zealand
| | - Rainer Borriss
- Humboldt-Universität zu Berlin, Institut für Biologie, Berlin, Germany.,Nord Reet UG, Marienstr. 27a, 17489, Greifswald, Germany
| | - Surya Pratap Singh
- Department of Biochemistry, Faculty of Science, Banaras Hindu University, Varanasi, India
| | - Miguel Angel Blázquez
- Instituto de Biología Molecular y Celular de Plantas, CSIC-Universitat Politècnica de València, 46022, Valencia, Spain
| | - Estibaliz Sansinenea
- Facultad De Ciencias Químicas, Benemérita Universidad Autónoma De Puebla, 72590, Puebla, Pue, México.
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18
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Song S, Yin W, Sun X, Cui B, Huang L, Li P, Yang L, Zhou J, Deng Y. Anthranilic acid from Ralstonia solanacearum plays dual roles in intraspecies signalling and inter-kingdom communication. THE ISME JOURNAL 2020; 14:2248-2260. [PMID: 32457502 PMCID: PMC7608240 DOI: 10.1038/s41396-020-0682-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 05/02/2020] [Accepted: 05/07/2020] [Indexed: 11/25/2022]
Abstract
Quorum sensing (QS) signals are widely utilized by bacteria to regulate biological functions in response to cell population density. Previous studies have demonstrated that Ralstonia solanacearum employs two different types of QS systems. We report here that anthranilic acid controls important biological functions and the production of QS signals in R. solanacearum. It was demonstrated that the biosynthesis of anthranilic acid is mainly performed by TrpEG. The accumulation of anthranilic acid and the transcription of trpEG occur in a cell density-dependent manner in R. solanacearum. Both the anthranilic acid and TrpEG homologues are conserved in various bacterial species. Moreover, we show that Sporisorium scitamineum sexual mating and hypha formation are strongly inhibited by the addition of exogenous anthranilic acid. Our results suggest that anthranilic acid is important for the physiology of bacteria in addition to its role in inter-kingdom communication.
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Affiliation(s)
- Shihao Song
- College of Agriculture, South China Agricultural University, Guangzhou, 510642, China
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Guangzhou, 510275, China
| | - Wenfang Yin
- College of Agriculture, South China Agricultural University, Guangzhou, 510642, China
| | - Xiuyun Sun
- College of Agriculture, South China Agricultural University, Guangzhou, 510642, China
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Guangzhou, 510275, China
| | - Binbin Cui
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Guangzhou, 510275, China
| | - Lei Huang
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Guangzhou, 510275, China
| | - Peng Li
- Ministry of Education Key Laboratory for Ecology of Tropical Islands, College of Life Sciences, Hainan Normal University, Haikou, 571158, China
| | - Liang Yang
- School of Medicine, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Jianuan Zhou
- College of Agriculture, South China Agricultural University, Guangzhou, 510642, China
| | - Yinyue Deng
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Guangzhou, 510275, China.
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Chane A, Bourigault Y, Bouteiller M, Konto-Ghiorghi Y, Merieau A, Barbey C, Latour X. Close-up on a bacterial informational war in the geocaulosphere. Can J Microbiol 2020; 66:447-454. [DOI: 10.1139/cjm-2019-0546] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The geocaulosphere is home to microbes that establish communication between themselves and others that disrupt them. These cell-to-cell communication systems are based on the synthesis and perception of signaling molecules, of which the best known belong to the N-acyl-homoserine lactone (AHL) family. Among indigenous bacteria, certain Gram-positive actinobacteria can sense AHLs produced by soft-rot Gram-negative phytopathogens and can degrade the quorum-sensing AHL signals to impair the expression of virulence factors. We mimicked this interaction by introducing dual-color reporter strains suitable for monitoring both the location of the cells and their quorum-sensing and -quenching activities, in potato tubers. The exchange of AHL signals within the pathogen’s cell quorum was clearly detected by the presence of bright green fluorescence instead of blue in a portion of Pectobacterium-tagged cells. This phenomenon in Rhodococcus cells was accompanied by a change from red fluorescence to orange, showing that the disappearance of signaling molecules is due to rhodococcal AHL degradation rather than the inhibition of AHL production. Rhodococci are victorious in this fight for the control of AHL-based communication, as their jamming activity is powerful enough to prevent the onset of disease symptoms.
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Affiliation(s)
- Andrea Chane
- Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM EA 4312) - Normandie Université - LMSM, 55 rue Saint-Germain, 27000 Evreux, France & Structure Fédérative de Recherche Normandie Végétale 4277 (NORVEGE)
| | - Yvann Bourigault
- Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM EA 4312) - Normandie Université - LMSM, 55 rue Saint-Germain, 27000 Evreux, France & Structure Fédérative de Recherche Normandie Végétale 4277 (NORVEGE)
| | - Mathilde Bouteiller
- Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM EA 4312) - Normandie Université - LMSM, 55 rue Saint-Germain, 27000 Evreux, France & Structure Fédérative de Recherche Normandie Végétale 4277 (NORVEGE)
- Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM EA 4312) - Normandie Université - LMSM, 55 rue Saint-Germain, 27000 Evreux, France & Structure Fédérative de Recherche Normandie Végétale 4277 (NORVEGE)
| | - Yoan Konto-Ghiorghi
- Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM EA 4312) - Normandie Université - LMSM, 55 rue Saint-Germain, 27000 Evreux, France & Structure Fédérative de Recherche Normandie Végétale 4277 (NORVEGE)
- Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM EA 4312) - Normandie Université - LMSM, 55 rue Saint-Germain, 27000 Evreux, France & Structure Fédérative de Recherche Normandie Végétale 4277 (NORVEGE)
| | - Annabelle Merieau
- Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM EA 4312) - Normandie Université - LMSM, 55 rue Saint-Germain, 27000 Evreux, France & Structure Fédérative de Recherche Normandie Végétale 4277 (NORVEGE)
- Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM EA 4312) - Normandie Université - LMSM, 55 rue Saint-Germain, 27000 Evreux, France & Structure Fédérative de Recherche Normandie Végétale 4277 (NORVEGE)
| | - Corinne Barbey
- Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM EA 4312) - Normandie Université - LMSM, 55 rue Saint-Germain, 27000 Evreux, France & Structure Fédérative de Recherche Normandie Végétale 4277 (NORVEGE)
- Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM EA 4312) - Normandie Université - LMSM, 55 rue Saint-Germain, 27000 Evreux, France & Structure Fédérative de Recherche Normandie Végétale 4277 (NORVEGE)
| | - Xavier Latour
- Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM EA 4312) - Normandie Université - LMSM, 55 rue Saint-Germain, 27000 Evreux, France & Structure Fédérative de Recherche Normandie Végétale 4277 (NORVEGE)
- Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM EA 4312) - Normandie Université - LMSM, 55 rue Saint-Germain, 27000 Evreux, France & Structure Fédérative de Recherche Normandie Végétale 4277 (NORVEGE)
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20
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Fan J, Ma L, Zhao C, Yan J, Che S, Zhou Z, Wang H, Yang L, Hu B. Transcriptome of Pectobacterium carotovorum subsp. carotovorum PccS1 infected in calla plants in vivo highlights a spatiotemporal expression pattern of genes related to virulence, adaptation, and host response. MOLECULAR PLANT PATHOLOGY 2020; 21:871-891. [PMID: 32267092 PMCID: PMC7214478 DOI: 10.1111/mpp.12936] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 02/14/2020] [Accepted: 02/29/2020] [Indexed: 06/11/2023]
Abstract
Bacterial pathogens from the genus Pectobacterium cause soft rot in various plants, and result in important economic losses worldwide. We understand much about how these pathogens digest their hosts and protect themselves against plant defences, as well as some regulatory networks in these processes. However, the spatiotemporal expression of genome-wide infection of Pectobacterium remains unclear, although researchers analysed this in some phytopathogens. In the present work, comparing the transcriptome profiles from cellular infection with growth in minimal and rich media, RNA-Seq analyses revealed that the differentially expressed genes (log2 -fold ratio ≥ 1.0) in the cells of Pectobacterium carotovorum subsp. carotovorum PccS1 recovered at a series of time points after inoculation in the host in vivo covered approximately 50% of genes in the genome. Based on the dynamic expression changes in infection, the significantly differentially expressed genes (log2 -fold ratio ≥ 2.0) were classified into five types, and the main expression pattern of the genes for carbohydrate metabolism underlying the processes of infection was identified. The results are helpful to our understanding of the inducement of host plant and environmental adaption of Pectobacterium. In addition, our results demonstrate that maceration caused by PccS1 is due to the depression of callose deposition in the plant for resistance by the pathogenesis-related genes and the superlytic ability of pectinolytic enzymes produced in PccS1, rather than the promotion of plant cell death elicited by the T3SS of bacteria as described in previous work.
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Affiliation(s)
- Jiaqin Fan
- Laboratory of BacteriologyDepartment of Plant PathologyNanjing Agricultural UniversityNanjingChina
| | - Lin Ma
- Laboratory of BacteriologyDepartment of Plant PathologyNanjing Agricultural UniversityNanjingChina
| | - Chendi Zhao
- Laboratory of BacteriologyDepartment of Plant PathologyNanjing Agricultural UniversityNanjingChina
| | - Jingyuan Yan
- Laboratory of BacteriologyDepartment of Plant PathologyNanjing Agricultural UniversityNanjingChina
| | - Shu Che
- Laboratory of BacteriologyDepartment of Plant PathologyNanjing Agricultural UniversityNanjingChina
| | - Zhaowei Zhou
- Laboratory of BacteriologyDepartment of Plant PathologyNanjing Agricultural UniversityNanjingChina
| | - Huan Wang
- Laboratory of BacteriologyDepartment of Plant PathologyNanjing Agricultural UniversityNanjingChina
| | - Liuke Yang
- Laboratory of BacteriologyDepartment of Plant PathologyNanjing Agricultural UniversityNanjingChina
| | - Baishi Hu
- Laboratory of BacteriologyDepartment of Plant PathologyNanjing Agricultural UniversityNanjingChina
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21
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Zhang H, Wei J, Qian W, Deng C. Analysis of HrpG regulons and HrpG-interacting proteins by ChIP-seq and affinity proteomics in Xanthomonas campestris. MOLECULAR PLANT PATHOLOGY 2020; 21:388-400. [PMID: 31916392 PMCID: PMC7036363 DOI: 10.1111/mpp.12903] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 11/06/2019] [Accepted: 11/27/2019] [Indexed: 06/02/2023]
Abstract
Gamma-proteobacteria Xanthomonas spp. cause at least 350 different plant diseases among important agricultural crops, which result in serious yield losses. Xanthomonas spp. rely mainly on the type III secretion system (T3SS) to infect their hosts and induce a hypersensitive response in nonhosts. HrpG, the master regulator of the T3SS, plays the dominant role in bacterial virulence. In this study, we used chromatin immunoprecipitation followed by sequencing (ChIP-seq) and tandem affinity purification (TAP) to systematically characterize the HrpG regulon and HrpG interacting proteins in vivo. We obtained 186 candidate HrpG downstream genes from the ChIP-seq analysis, which represented the genomic-wide regulon spectrum. A consensus HrpG-binding motif was obtained and three T3SS genes, hpa2, hrcU, and hrpE, were confirmed to be directly transcriptionally activated by HrpG in the inducing medium. A total of 273 putative HrpG interacting proteins were identified from the TAP data and the DNA-binding histone-like HU protein of Xanthomonas campestris pv. campestris (HUxcc ) was proved to be involved in bacterial virulence by increasing the complexity and intelligence of the bacterial signalling pathways in the T3SS.
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Affiliation(s)
- Hong‐Yu Zhang
- State Key Laboratory of Plant GenomicsInstitute of MicrobiologyChinese Academy of SciencesBeijingChina
- College of Life SciencesUniversity of Chinese Academy of SciencesBeijingChina
| | - Jin‐Wei Wei
- State Key Laboratory of Plant GenomicsInstitute of MicrobiologyChinese Academy of SciencesBeijingChina
- College of Life SciencesUniversity of Chinese Academy of SciencesBeijingChina
| | - Wei Qian
- State Key Laboratory of Plant GenomicsInstitute of MicrobiologyChinese Academy of SciencesBeijingChina
| | - Chao‐Ying Deng
- State Key Laboratory of Plant GenomicsInstitute of MicrobiologyChinese Academy of SciencesBeijingChina
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22
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Modulation of Quorum Sensing as an Adaptation to Nodule Cell Infection during Experimental Evolution of Legume Symbionts. mBio 2020; 11:mBio.03129-19. [PMID: 31992622 PMCID: PMC6989110 DOI: 10.1128/mbio.03129-19] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Over millions of years, changes have occurred in regulatory circuitries in response to genome reorganization and/or persistent changes in environmental conditions. How bacteria optimize regulatory circuitries is crucial to understand bacterial adaptation. Here, we analyzed the experimental evolution of the plant pathogen Ralstonia solanacearum into legume symbionts after the transfer of a natural plasmid encoding the essential mutualistic genes. We showed that the Phc quorum sensing system required for the virulence of the ancestral bacterium was reconfigured to improve intracellular infection of root nodules induced by evolved Ralstonia A single mutation in either the PhcB autoinducer synthase or the PhcQ regulator of the sensory cascade tuned the kinetics of activation of the central regulator PhcA in response to cell density so that the minimal stimulatory concentration of autoinducers needed for a given response was increased. Yet, a change in the expression of a PhcA target gene was observed in infection threads progressing in root hairs, suggesting early programming for the late accommodation of bacteria in nodule cells. Moreover, this delayed switch to the quorum sensing mode decreased the pathogenicity of the ancestral strain, illustrating the functional plasticity of regulatory systems and showing how a small modulation in signal response can produce drastic changes in bacterial lifestyle.IMPORTANCE Rhizobia are soil bacteria from unrelated genera able to form a mutualistic relationship with legumes. Bacteria induce the formation of root nodules, invade nodule cells, and fix nitrogen to the benefit of the plant. Rhizobial lineages emerged from the horizontal transfer of essential symbiotic genes followed by genome remodeling to activate and/or optimize the acquired symbiotic potential. This evolutionary scenario was replayed in a laboratory evolution experiment in which the plant pathogen Ralstonia solanacearum successively evolved the capacities to nodulate Mimosa pudica and poorly invade, then massively invade, nodule cells. In some lines, the improvement of intracellular infection was achieved by mutations modulating a quorum sensing regulatory system of the ancestral strain. This modulation that affects the activity of a central regulator during the earliest stages of symbiosis has a huge impact on late stages of symbiosis. This work showed that regulatory rewiring is the main driver of this pathogeny-symbiosis transition.
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23
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O’Malley MR, Chien C, Peck SC, Lin N, Anderson JC. A revised model for the role of GacS/GacA in regulating type III secretion by Pseudomonas syringae pv. tomato DC3000. MOLECULAR PLANT PATHOLOGY 2020; 21:139-144. [PMID: 31588661 PMCID: PMC6913209 DOI: 10.1111/mpp.12876] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
GacS/GacA is a conserved two-component system that functions as a master regulator of virulence-associated traits in many bacterial pathogens, including Pseudomonas spp., that collectively infect both plant and animal hosts. Among many GacS/GacA-regulated traits, type III secretion of effector proteins into host cells plays a critical role in bacterial virulence. In the opportunistic plant and animal pathogen Pseudomonas aeruginosa, GacS/GacA negatively regulates the expression of type III secretion system (T3SS)-encoding genes. However, in the plant pathogenic bacterium Pseudomonas syringae, strain-to-strain variation exists in the requirement of GacS/GacA for T3SS deployment, and this variability has limited the development of predictive models of how GacS/GacA functions in this species. In this work we re-evaluated the function of GacA in P. syringae pv. tomato DC3000. Contrary to previous reports, we discovered that GacA negatively regulates the expression of T3SS genes in DC3000, and that GacA is not required for DC3000 virulence inside Arabidopsis leaf tissue. However, our results show that GacA is required for full virulence of leaf surface-inoculated bacteria. These data significantly revise current understanding of GacS/GacA in regulating P. syringae virulence.
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Affiliation(s)
- Megan R. O’Malley
- Department of Botany and Plant PathologyOregon State UniversityCorvallisORUSA
| | - Ching‐Fang Chien
- Department of Agricultural ChemistryNational Taiwan UniversityTaipeiTaiwanR.O.C.
- Institute of Plant and Microbial BiologyAcademia SinicaTaipeiTaiwanR.O.C.
| | - Scott C. Peck
- Department of BiochemistryUniversity of MissouriColumbiaMOUSA
- Christopher S Bond Life Sciences CenterUniversity of MissouriColumbiaMOUSA
- Interdisciplinary Plant GroupUniversity of MissouriColumbiaMOUSA
| | - Nai‐Chun Lin
- Department of Agricultural ChemistryNational Taiwan UniversityTaipeiTaiwanR.O.C.
| | - Jeffrey C. Anderson
- Department of Botany and Plant PathologyOregon State UniversityCorvallisORUSA
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24
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Ye T, Zhou T, Fan X, Bhatt P, Zhang L, Chen S. Acinetobacter lactucae Strain QL-1, a Novel Quorum Quenching Candidate Against Bacterial Pathogen Xanthomonas campestris pv. campestris. Front Microbiol 2019; 10:2867. [PMID: 31921047 PMCID: PMC6929412 DOI: 10.3389/fmicb.2019.02867] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Accepted: 11/27/2019] [Indexed: 11/16/2022] Open
Abstract
Quorum sensing (QS) is a cell–cell communication mechanism among bacterial populations that is regulated through gene expression in response to cell density. The pathogenicity of Xanthomonas campestris pv. campestris (Xcc) is modulated by the diffusible signal factor (DSF)-mediated QS system. DSF is widely conserved in a variety of gram-negative bacterial pathogens. In this study, DSF-degrading bacteria and their enzymes were thoroughly explored as a biocontrol agent against Xcc. The results indicated that a novel DSF-degrading bacterium, Acinetobacter lactucae QL-1, effectively attenuated Xcc virulence through quorum quenching. Lab-based experiments indicated that plants inoculated with QL-1 and Xcc had less tissue decay than those inoculated with Xcc alone. Co-inoculation of strains Xcc and QL-1 significantly reduced the incidence and severity of disease in plants. Similarly, the application of crude enzymes of strain QL-1 substantially reduced the disease severity caused by Xcc. The results showed that strain QL-1 and its enzymes possess promising potential, which could be further investigated to better protect plants from DSF-dependent pathogens.
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Affiliation(s)
- Tian Ye
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Laboratory of Lingnan Modern Agricultural Science and Technology, South China Agricultural University, Guangzhou, China
| | - Tian Zhou
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Laboratory of Lingnan Modern Agricultural Science and Technology, South China Agricultural University, Guangzhou, China
| | - Xinghui Fan
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Laboratory of Lingnan Modern Agricultural Science and Technology, South China Agricultural University, Guangzhou, China
| | - Pankaj Bhatt
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Laboratory of Lingnan Modern Agricultural Science and Technology, South China Agricultural University, Guangzhou, China
| | - Lianhui Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Laboratory of Lingnan Modern Agricultural Science and Technology, South China Agricultural University, Guangzhou, China
| | - Shaohua Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Integrative Microbiology Research Centre, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Laboratory of Lingnan Modern Agricultural Science and Technology, South China Agricultural University, Guangzhou, China
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25
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Pham MT, Huang CM, Kirschner R. The plant growth-promoting potential of the mesophilic wood-rot mushroom Pleurotus pulmonarius. J Appl Microbiol 2019; 127:1157-1171. [PMID: 31291682 DOI: 10.1111/jam.14375] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 06/09/2019] [Accepted: 06/26/2019] [Indexed: 11/27/2022]
Abstract
AIMS To demonstrate the plant growth-promoting potential of a wood-decay mushroom. METHODS AND RESULTS A wild strain of a white rot fungus (Pleurotus pulmonarius) was found to convert 10 mmol l-1 L-tryptophan (TRP) to approximately 15 μg ml-1 indole-3-acetic acid (IAA) under the optimal growth conditions of 30°C and pH 5 for 15 days. Results of gas chromatography-mass spectrometry indicated IAA synthesis through the indole-3-pyruvic acid pathway when using cellulose as a sole carbon source. The mycelium as well as the culture filtrate promoted the growth and chlorophyll content of seedlings. In a monocotyledonous plant (rice), the number of lateral roots was increased experimentally, whereas in a dicotyledonous plant (tomato), the fungus led to an increased length of shoots and roots. CONCLUSIONS TRP-dependent IAA production was demonstrated for the first time for P. pulmonarius and may be responsible for enhancing plant growth in vitro. SIGNIFICANCE AND IMPACT OF THE STUDY Synthesis of IAA as the most prevalent phytohormone in plants has been demonstrated for soil microfungi. Pleurotus pulmonarius is reported as an IAA-producing wood-decay macrofungus. The higher temperature optimum of P. pulmonarius isolated from subtropical environment compared to other Pleurotus species from temperate regions makes it more suitable for application in subtropical/tropical regions.
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Affiliation(s)
- M T Pham
- Department of Biomedical Sciences & Engineering, National Central University, Taoyuan City, Taiwan
| | - C-M Huang
- Department of Biomedical Sciences & Engineering, National Central University, Taoyuan City, Taiwan
| | - R Kirschner
- School of Forestry and Resource Conservation, National Taiwan University, Taipei, Taiwan
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26
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Production of superfine green tea powder from processing wastes: Characterization of chemical composition and exploration of antimicrobial potential against Ralstonia solanacearum. Lebensm Wiss Technol 2019. [DOI: 10.1016/j.lwt.2019.01.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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27
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Yang LY, Yang LC, Gan YL, Wang L, Zhao WZ, He YQ, Jiang W, Jiang BL, Tang JL. Systematic Functional Analysis of Sigma (σ) Factors in the Phytopathogen Xanthomonas campestris Reveals Novel Roles in the Regulation of Virulence and Viability. Front Microbiol 2018; 9:1749. [PMID: 30123197 PMCID: PMC6085468 DOI: 10.3389/fmicb.2018.01749] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 07/12/2018] [Indexed: 11/13/2022] Open
Abstract
The black rot pathogen Xanthomonas campestris pv. campestris (Xcc) is a model organism for the study of plant bacterial pathogenesis mechanisms. In bacteria, σ factors serve as important regulatory elements that respond to various environmental signals and cues. Though Xcc encodes 15 putative σ factors little is known about their roles. As an approach to identify the potential role of each σ factor, we constructed mutations in each of the σ-factor genes as well as generating mutants deficient in multiple σ factors to assess these regulators potential additive functions. The work identified two σ70 factors essential for growth. Furthermore, the work discovered a third σ70 factor, RpoE1, important for virulence. Further studies revealed that RpoE1 positively regulates the expression of the hrp gene cluster that encodes the type III secretion system (T3SS) which determines the pathogenicity and hypersensitive response of Xcc on plants. In vivo and in vitro studies demonstrated that RpoE1 could bind to the promoter region and promote transcription of hrpX, a gene encoding a key regulator of the hrp genes. Overall, this systematic analysis reveals important roles in Xcc survival and virulence for previously uncharacterized σ70 factors that may become important targets for disease control.
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Affiliation(s)
- Li-Yan Yang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Li-Chao Yang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Yong-Liang Gan
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Lin Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Wan-Zong Zhao
- Guangxi Key Laboratory of Power System Optimization and Energy Technology, Guangxi University, Nanning, China
| | - Yong-Qiang He
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Wei Jiang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Bo-Le Jiang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
| | - Ji-Liang Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning, China
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28
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Nobori T, Mine A, Tsuda K. Molecular networks in plant-pathogen holobiont. FEBS Lett 2018; 592:1937-1953. [PMID: 29714033 DOI: 10.1002/1873-3468.13071] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 04/13/2018] [Accepted: 04/23/2018] [Indexed: 12/31/2022]
Abstract
Plant immune receptors enable detection of a multitude of microbes including pathogens. The recognition of microbes activates various plant signaling pathways, such as those mediated by phytohormones. Over the course of coevolution with microbes, plants have expanded their repertoire of immune receptors and signaling components, resulting in highly interconnected plant immune networks. These immune networks enable plants to appropriately respond to different types of microbes and to coordinate immune responses with developmental programs and environmental stress responses. However, the interconnectivity in plant immune networks is exploited by microbial pathogens to promote pathogen fitness in plants. Analogous to plant immune networks, virulence-related pathways in bacterial pathogens are also interconnected. Accumulating evidence implies that some plant-derived compounds target bacterial virulence networks. Thus, the plant immune and bacterial virulence networks intimately interact with each other. Here, we highlight recent insights into the structures of the plant immune and bacterial virulence networks and the interactions between them. We propose that small molecules derived from plants and/or bacterial pathogens connect the two molecular networks, forming supernetworks in the plant-bacterial pathogen holobiont.
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Affiliation(s)
- Tatsuya Nobori
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Akira Mine
- Ritsumeikan Global Innovation Research Organization, Ritsumeikan University, Kusatsu, Japan.,JST, PRESTO, Kawaguchi-shi, Japan
| | - Kenichi Tsuda
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, Germany
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29
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Pédron J, Chapelle E, Alunni B, Van Gijsegem F. Transcriptome analysis of the Dickeya dadantii PecS regulon during the early stages of interaction with Arabidopsis thaliana. MOLECULAR PLANT PATHOLOGY 2018; 19:647-663. [PMID: 28295994 PMCID: PMC6638149 DOI: 10.1111/mpp.12549] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 02/21/2017] [Accepted: 03/13/2017] [Indexed: 05/10/2023]
Abstract
PecS is one of the major global regulators controlling the virulence of Dickeya dadantii, a broad-host-range phytopathogenic bacterium causing soft rot on several plant families. To define the PecS regulon during plant colonization, we analysed the global transcriptome profiles in wild-type and pecS mutant strains during the early colonization of the leaf surfaces and in leaf tissue just before the onset of symptoms, and found that the PecS regulon consists of more than 600 genes. About one-half of these genes are down-regulated in the pecS mutant; therefore, PecS has both positive and negative regulatory roles that may be direct or indirect. Indeed, PecS also controls the regulation of a few dozen regulatory genes, demonstrating that this global regulator is at or near the top of a major regulatory cascade governing adaptation to growth in planta. Notably, PecS acts mainly at the very beginning of infection, not only to prevent virulence gene induction, but also playing an active role in the adaptation of the bacterium to the epiphytic habitat. Comparison of the patterns of gene expression inside leaf tissues and during early colonization of leaf surfaces in the wild-type bacterium revealed 637 genes modulated between these two environments. More than 40% of these modulated genes are part of the PecS regulon, emphasizing the prominent role of PecS during plant colonization.
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Affiliation(s)
- Jacques Pédron
- Interactions Plantes Pathogènes, AgroParisTech, INRA, UPMC Université Paris 06, Paris, 75005, France
- iEES (Institut d'Ecologie et des Sciences de l'Environnement de Paris), Sorbonne Universités, UPMC Université Paris 06, Diderot Université Paris 07, UPEC Université Paris 12, CNRS, INRA, IRD, Paris, 75005, France
| | - Emilie Chapelle
- Interactions Plantes Pathogènes, AgroParisTech, INRA, UPMC Université Paris 06, Paris, 75005, France
| | - Benoît Alunni
- Interactions Plantes Pathogènes, AgroParisTech, INRA, UPMC Université Paris 06, Paris, 75005, France
- Institute for Integrative Biology of the Cell, UMR 9198, CNRS/Universite Paris-Sud/CEA, Gif-sur-Yvette, 91198, France
| | - Frédérique Van Gijsegem
- Interactions Plantes Pathogènes, AgroParisTech, INRA, UPMC Université Paris 06, Paris, 75005, France
- iEES (Institut d'Ecologie et des Sciences de l'Environnement de Paris), Sorbonne Universités, UPMC Université Paris 06, Diderot Université Paris 07, UPEC Université Paris 12, CNRS, INRA, IRD, Paris, 75005, France
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30
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Liang X, Yu X, Pan X, Wu J, Duan Y, Wang J, Zhou M. A thiadiazole reduces the virulence of Xanthomonas oryzae pv. oryzae by inhibiting the histidine utilization pathway and quorum sensing. MOLECULAR PLANT PATHOLOGY 2018; 19:116-128. [PMID: 27756112 PMCID: PMC6638098 DOI: 10.1111/mpp.12503] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Revised: 10/10/2016] [Accepted: 10/17/2016] [Indexed: 05/08/2023]
Abstract
Thiazole, isothiazole, thiadiazole and their derivatives are widely thought to induce host defences against plant pathogens. In this article, we report that bismerthiazol, a thiadiazole molecule, reduces disease by inhibiting the histidine utilization (Hut) pathway and quorum sensing (QS). Bismerthiazol provides excellent control of bacterial rice leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo), but does not greatly inhibit Xoo growth in vitro. According to RNA-sequencing analysis, the transcription of the Hut pathway genes of Xoo ZJ173 was inhibited after 4.5 and 9.0 h of bismerthiazol treatment. Functional studies of hutG and hutU indicated that the Hut pathway had little effect on the growth and bismerthiazol sensitivity of Xoo in vitro, but significantly reduced the aggregation of Xoo cells. Deletion mutants of hutG or hutU were more motile, produced less biofilm and were less virulent than the wild-type, indicating that the Hut pathway is involved in QS and contributes to virulence. The overexpression of the hutG-U operons in ZJ173 reduced Xoo control by bismerthiazol. Bismerthiazol did not inhibit the transcription of Hut pathway genes, QS or virulence of the bismerthiazol-resistant strain 2-1-1. The results indicate that bismerthiazol reduces Xoo virulence by inhibiting the Hut pathway and QS.
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Affiliation(s)
- Xiaoyu Liang
- College of Plant Protection, Nanjing Agricultural University, Key Laboratory of PesticideJiangsu ProvinceNanjing210095China
| | - Xiaoyue Yu
- College of Plant Protection, Nanjing Agricultural University, Key Laboratory of PesticideJiangsu ProvinceNanjing210095China
| | - Xiayan Pan
- College of Plant Protection, Nanjing Agricultural University, Key Laboratory of PesticideJiangsu ProvinceNanjing210095China
| | - Jian Wu
- College of Plant Protection, Nanjing Agricultural University, Key Laboratory of PesticideJiangsu ProvinceNanjing210095China
| | - Yabing Duan
- College of Plant Protection, Nanjing Agricultural University, Key Laboratory of PesticideJiangsu ProvinceNanjing210095China
| | - Jianxin Wang
- College of Plant Protection, Nanjing Agricultural University, Key Laboratory of PesticideJiangsu ProvinceNanjing210095China
| | - Mingguo Zhou
- College of Plant Protection, Nanjing Agricultural University, Key Laboratory of PesticideJiangsu ProvinceNanjing210095China
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31
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Shanmugam G, Jeon J. Computer-Aided Drug Discovery in Plant Pathology. THE PLANT PATHOLOGY JOURNAL 2017; 33:529-542. [PMID: 29238276 PMCID: PMC5720600 DOI: 10.5423/ppj.rw.04.2017.0084] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 09/06/2017] [Accepted: 09/06/2017] [Indexed: 05/31/2023]
Abstract
Control of plant diseases is largely dependent on use of agrochemicals. However, there are widening gaps between our knowledge on plant diseases gained from genetic/mechanistic studies and rapid translation of the knowledge into target-oriented development of effective agrochemicals. Here we propose that the time is ripe for computer-aided drug discovery/design (CADD) in molecular plant pathology. CADD has played a pivotal role in development of medically important molecules over the last three decades. Now, explosive increase in information on genome sequences and three dimensional structures of biological molecules, in combination with advances in computational and informational technologies, opens up exciting possibilities for application of CADD in discovery and development of agrochemicals. In this review, we outline two categories of the drug discovery strategies: structure- and ligand-based CADD, and relevant computational approaches that are being employed in modern drug discovery. In order to help readers to dive into CADD, we explain concepts of homology modelling, molecular docking, virtual screening, and de novo ligand design in structure-based CADD, and pharmacophore modelling, ligand-based virtual screening, quantitative structure activity relationship modelling and de novo ligand design for ligand-based CADD. We also provide the important resources available to carry out CADD. Finally, we present a case study showing how CADD approach can be implemented in reality for identification of potent chemical compounds against the important plant pathogens, Pseudomonas syringae and Colletotrichum gloeosporioides.
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Affiliation(s)
| | - Junhyun Jeon
- Corresponding author. Phone) +82-53-810-3030, FAX) +82-53-810-4769, E-mail)
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Gorshkov V, Kwenda S, Petrova O, Osipova E, Gogolev Y, Moleleki LN. Global Gene Expression Analysis of Cross-Protected Phenotype of Pectobacterium atrosepticum. PLoS One 2017; 12:e0169536. [PMID: 28081189 PMCID: PMC5230779 DOI: 10.1371/journal.pone.0169536] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Accepted: 12/19/2016] [Indexed: 12/25/2022] Open
Abstract
The ability to adapt to adverse conditions permits many bacterial species to be virtually ubiquitous and survive in a variety of ecological niches. This ability is of particular importance for many plant pathogenic bacteria that should be able to exist, except for their host plants, in different environments e.g. soil, water, insect-vectors etc. Under some of these conditions, bacteria encounter absence of nutrients and persist, acquiring new properties related to resistance to a variety of stress factors (cross-protection). Although many studies describe the phenomenon of cross-protection and several regulatory components that induce the formation of resistant cells were elucidated, the global comparison of the physiology of cross-protected phenotype and growing cells has not been performed. In our study, we took advantage of RNA-Seq technology to gain better insights into the physiology of cross-protected cells on the example of a harmful phytopathogen, Pectobacterium atrosepticum (Pba) that causes crop losses all over the world. The success of this bacterium in plant colonization is related to both its virulence potential and ability to persist effectively under various stress conditions (including nutrient deprivation) retaining the ability to infect plants afterwards. In our previous studies, we showed Pba to be advanced in applying different adaptive strategies that led to manifestation of cell resistance to multiple stress factors. In the present study, we determined the period necessary for the formation of cross-protected Pba phenotype under starvation conditions, and compare the transcriptome profiles of non-adapted growing cells and of adapted cells after the cross-protective effect has reached the maximal level. The obtained data were verified using qRT-PCR. Genes that were expressed differentially (DEGs) in two cell types were classified into functional groups and categories using different approaches. As a result, we portrayed physiological features that distinguish cross-protected phenotype from the growing cells.
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Affiliation(s)
- Vladimir Gorshkov
- Kazan Institute of Biochemistry and Biophysics of Kazan Science Centre of Russian Academy of Sciences, Kazan, Russia
- Department of Biochemistry and Biotechnology, Kazan Federal University, Kazan, Russia
| | - Stanford Kwenda
- Department of Microbiology and Plant Pathology, University of Pretoria, Pretoria, South Africa
- Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Olga Petrova
- Kazan Institute of Biochemistry and Biophysics of Kazan Science Centre of Russian Academy of Sciences, Kazan, Russia
| | - Elena Osipova
- Kazan Institute of Biochemistry and Biophysics of Kazan Science Centre of Russian Academy of Sciences, Kazan, Russia
| | - Yuri Gogolev
- Kazan Institute of Biochemistry and Biophysics of Kazan Science Centre of Russian Academy of Sciences, Kazan, Russia
- Department of Biochemistry and Biotechnology, Kazan Federal University, Kazan, Russia
| | - Lucy N. Moleleki
- Department of Microbiology and Plant Pathology, University of Pretoria, Pretoria, South Africa
- Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
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Hersemann L, Wibberg D, Blom J, Goesmann A, Widmer F, Vorhölter FJ, Kölliker R. Comparative genomics of host adaptive traits in Xanthomonas translucens pv. graminis. BMC Genomics 2017; 18:35. [PMID: 28056815 PMCID: PMC5217246 DOI: 10.1186/s12864-016-3422-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2016] [Accepted: 12/14/2016] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Xanthomonas translucens pathovars differ in their individual host ranges among Poaceae. As the causal agent of bacterial wilt in Italian ryegrass (Lolium multiflorum Lam.), X. translucens pv. graminis (Xtg) is one of the most important bacterial pathogens in temperate grassland regions. The genomes of six Xtg strains from Switzerland, Norway, and New Zealand were sequenced in order to gain insight into conserved genomic traits from organisms covering a wide geographical range. Subsequent comparative analysis with previously published genome data of seven non-graminis X. translucens strains including the pathovars arrhenatheri, poae, phlei, cerealis, undulosa, and translucens was conducted to identify candidate genes linked to the host adaptation of Xtg to Italian ryegrass. RESULTS Phylogenetic analysis revealed a tight clustering of Xtg strains, which were found to share a large core genome. Conserved genomic traits included a non-canonical type III secretion system (T3SS) and a type IV pilus (T4P), which both revealed distinct primary structures of the pilins when compared to the non-graminis X. translucens strains. Xtg-specific traits that had no homologues in the other X. translucens strains were further found to comprise several hypothetical proteins, a TonB-dependent receptor, transporters, and effector proteins as well as toxin-antitoxin systems and DNA methyltransferases. While a nearly complete flagellar gene cluster was identified in one of the sequenced Xtg strains, phenotypic analysis pointed to swimming-deficiency as a common trait of the pathovar graminis. CONCLUSION Our study suggests that host adaptation of X. translucens pv. graminis may be conferred by a combination of pathovar-specific effector proteins, regulatory mechanisms, and adapted nutrient acquisition. Sequence deviations of pathogen-associated molecular patterns (PAMPs), as observed for the pilins of the T4P and T3SS, are moreover likely to impede perception by the plant defense machinery and thus facilitate successful host colonization of Italian ryegrass.
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Affiliation(s)
| | - Daniel Wibberg
- Center for Biotechnology, Bielefeld University, 33615, Bielefeld, Germany
| | - Jochen Blom
- Bioinformatics and Systems Biology, Justus Liebig University Giessen, 35392, Giessen, Germany
| | - Alexander Goesmann
- Bioinformatics and Systems Biology, Justus Liebig University Giessen, 35392, Giessen, Germany
| | - Franco Widmer
- Molecular Ecology, Agroscope, 8046, Zurich, Switzerland
| | - Frank-Jörg Vorhölter
- Center for Biotechnology, Bielefeld University, 33615, Bielefeld, Germany
- MVZ Dr. Eberhard & Partner Dortmund, 44137, Dortmund, Germany
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Joshi JR, Khazanov N, Senderowitz H, Burdman S, Lipsky A, Yedidia I. Plant phenolic volatiles inhibit quorum sensing in pectobacteria and reduce their virulence by potential binding to ExpI and ExpR proteins. Sci Rep 2016; 6:38126. [PMID: 27905512 PMCID: PMC5131480 DOI: 10.1038/srep38126] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 11/07/2016] [Indexed: 11/22/2022] Open
Abstract
Quorum sensing (QS) is a population density-dependent regulatory system in bacteria that couples gene expression to cell density through accumulation of diffusible signaling molecules. Pectobacteria are causal agents of soft rot disease in a range of economically important crops. They rely on QS to coordinate their main virulence factor, production of plant cell wall degrading enzymes (PCWDEs). Plants have evolved an array of antimicrobial compounds to anticipate and cope with pathogens, of which essential oils (EOs) are widely recognized. Here, volatile EOs, carvacrol and eugenol, were shown to specifically interfere with QS, the master regulator of virulence in pectobacteria, resulting in strong inhibition of QS genes, biofilm formation and PCWDEs, thereby leading to impaired infection. Accumulation of the signal molecule N-acylhomoserine lactone declined upon treatment with EOs, suggesting direct interaction of EOs with either homoserine lactone synthase (ExpI) or with the regulatory protein (ExpR). Homology models of both proteins were constructed and docking simulations were performed to test the above hypotheses. The resulting binding modes and docking scores of carvacrol and eugenol support potential binding to ExpI/ExpR, with stronger interactions than previously known inhibitors of both proteins. The results demonstrate the potential involvement of phytochemicals in the control of Pectobacterium.
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Affiliation(s)
- Janak Raj Joshi
- Department of Plant Pathology and Microbiology and the Otto Warburg Minerva Center for Agricultural Biotechnology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.,Department of Plant Sciences, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel
| | - Netaly Khazanov
- Department of Chemistry, Bar-Ilan University, Ramat-Gan, Israel
| | | | - Saul Burdman
- Department of Plant Pathology and Microbiology and the Otto Warburg Minerva Center for Agricultural Biotechnology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Alexander Lipsky
- Department of Plant Sciences, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel
| | - Iris Yedidia
- Department of Plant Sciences, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel
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The structure of the lipooligosaccharide from Xanthomonas oryzae pv. Oryzae: the causal agent of the bacterial leaf blight in rice. Carbohydr Res 2016; 427:38-43. [DOI: 10.1016/j.carres.2016.03.026] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 03/29/2016] [Accepted: 03/30/2016] [Indexed: 01/09/2023]
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Bzdrenga J, Daudé D, Rémy B, Jacquet P, Plener L, Elias M, Chabrière E. Biotechnological applications of quorum quenching enzymes. Chem Biol Interact 2016; 267:104-115. [PMID: 27223408 DOI: 10.1016/j.cbi.2016.05.028] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 05/04/2016] [Accepted: 05/20/2016] [Indexed: 11/12/2022]
Abstract
Numerous bacteria use quorum sensing (QS) to synchronize their behavior and monitor their population density. They use signaling molecules known as autoinducers (AI's) that are synthesized and secreted into their local environment to regulate QS-dependent gene expression. Among QS-regulated pathways, biofilm formation and virulence factor secretion are particularly problematic as they are involved in surface-attachment, antimicrobial agent resistance, toxicity, and pathogenicity. Targeting QS represents a promising strategy to inhibit undesirable bacterial traits. This strategy, referred to as quorum quenching (QQ), includes QS-inhibitors and QQ enzymes. These approaches are appealing because they do not directly challenge bacterial survival, and consequently selection pressure may be low, yielding a lower occurrence of resistance. QQ enzymes are particularly promising because they act extracellularly to degrade AI's and can be used in catalytic quantities. This review draws an overview of QQ enzyme related applications, covering several economically important fields such as agriculture, aquaculture, biofouling and health issues. Finally, the possibility of resistance mechanism occurrence to QQ strategies is discussed.
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Affiliation(s)
- Janek Bzdrenga
- Aix Marseille Université, URMITE, UM63, CNRS 7278, IRD 198, INSERM 1095, Marseille, France
| | - David Daudé
- Gene&GreenTK, Faculté de Médecine, 27 boulevard Jean Moulin, 13385 Marseille Cedex 5, France
| | - Benjamin Rémy
- Aix Marseille Université, URMITE, UM63, CNRS 7278, IRD 198, INSERM 1095, Marseille, France; Gene&GreenTK, Faculté de Médecine, 27 boulevard Jean Moulin, 13385 Marseille Cedex 5, France
| | - Pauline Jacquet
- Aix Marseille Université, URMITE, UM63, CNRS 7278, IRD 198, INSERM 1095, Marseille, France
| | - Laure Plener
- Gene&GreenTK, Faculté de Médecine, 27 boulevard Jean Moulin, 13385 Marseille Cedex 5, France
| | - Mikael Elias
- University of Minnesota, Department of Biochemistry, Molecular Biology and Biophysics & Biotechnology Institute, St. Paul, MN 55108, USA
| | - Eric Chabrière
- Aix Marseille Université, URMITE, UM63, CNRS 7278, IRD 198, INSERM 1095, Marseille, France.
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Joshi JR, Burdman S, Lipsky A, Yariv S, Yedidia I. Plant phenolic acids affect the virulence of Pectobacterium aroidearum and P. carotovorum ssp. brasiliense via quorum sensing regulation. MOLECULAR PLANT PATHOLOGY 2016; 17:487-500. [PMID: 26177258 PMCID: PMC6638513 DOI: 10.1111/mpp.12295] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Several studies have reported effects of the plant phenolic acids cinnamic acid (CA) and salicylic acid (SA) on the virulence of soft rot enterobacteria. However, the mechanisms involved in these processes are not yet fully understood. Here, we investigated whether CA and SA interfere with the quorum sensing (QS) system of two Pectobacterium species, P. aroidearum and P. carotovorum ssp. brasiliense, which are known to produce N-acyl-homoserine lactone (AHL) QS signals. Our results clearly indicate that both phenolic compounds affect the QS machinery of the two species, consequently altering the expression of bacterial virulence factors. Although, in control treatments, the expression of QS-related genes increased over time, the exposure of bacteria to non-lethal concentrations of CA or SA inhibited the expression of QS genes, including expI, expR, PC1_1442 (luxR transcriptional regulator) and luxS (a component of the AI-2 system). Other virulence genes known to be regulated by the QS system, such as pecS, pel, peh and yheO, were also down-regulated relative to the control. In agreement with the low levels of expression of expI and expR, CA and SA also reduced the level of the AHL signal. The effects of CA and SA on AHL signalling were confirmed in compensation assays, in which exogenous application of N-(β-ketocaproyl)-l-homoserine lactone (eAHL) led to the recovery of the reduction in virulence caused by the two phenolic acids. Collectively, the results of gene expression studies, bioluminescence assays, virulence assays and compensation assays with eAHL clearly support a mechanism by which CA and SA interfere with Pectobacterium virulence via the QS machinery.
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Affiliation(s)
- Janak Raj Joshi
- Department of Plant Pathology and Microbiology and the Otto Warburg Minerva Center for Agricultural Biotechnology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, 76100, Rehovot, Israel
- Department of Plant Sciences, Agricultural Research Organization, The Volcani Center, 50250, Bet Dagan, Israel
| | - Saul Burdman
- Department of Plant Pathology and Microbiology and the Otto Warburg Minerva Center for Agricultural Biotechnology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, 76100, Rehovot, Israel
| | - Alexander Lipsky
- Department of Plant Sciences, Agricultural Research Organization, The Volcani Center, 50250, Bet Dagan, Israel
| | - Shaked Yariv
- Department of Plant Sciences, Agricultural Research Organization, The Volcani Center, 50250, Bet Dagan, Israel
| | - Iris Yedidia
- Department of Plant Sciences, Agricultural Research Organization, The Volcani Center, 50250, Bet Dagan, Israel
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Wu D, Ding W, Zhang Y, Liu X, Yang L. Oleanolic Acid Induces the Type III Secretion System of Ralstonia solanacearum. Front Microbiol 2015; 6:1466. [PMID: 26732647 PMCID: PMC4686671 DOI: 10.3389/fmicb.2015.01466] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2015] [Accepted: 12/07/2015] [Indexed: 12/18/2022] Open
Abstract
Ralstonia solanacearum, the causal agent of bacterial wilt, can naturally infect a wide range of host plants. The type III secretion system (T3SS) is a major virulence determinant in this bacterium. Studies have shown that plant-derived compounds are able to inhibit or induce the T3SS in some plant pathogenic bacteria, though no specific T3SS inhibitor or inducer has yet been identified in R. solanacearum. In this study, a total of 50 different compounds were screened and almost half of them (22 of 50) significantly inhibited or induced the T3SS expression of R. solanacearum. Based on the strong induction activity on T3SS, the T3SS inducer oleanolic acid (OA) was chosen for further study. We found that OA induced the expression of T3SS through the HrpG-HrpB pathway. Some type III effector genes were induced in T3SS inducing medium supplemented with OA. In addition, OA targeted only the T3SS and did not affect other virulence determinants. Finally, we observed that induction of T3SS by OA accelerated disease progress on tobacco. Overall our results suggest that plant-derived compounds are an abundant source of R. solanacearum T3SS regulators, which could prove useful as tools to interrogate the regulation of this key virulence pathway.
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Affiliation(s)
- Dousheng Wu
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest University Chongqing, China
| | - Wei Ding
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest University Chongqing, China
| | - Yong Zhang
- Research Center of Bioenergy and Bioremediation, College of Resources and Environment, Southwest University Chongqing, China
| | - Xuejiao Liu
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest University Chongqing, China
| | - Liang Yang
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest University Chongqing, China
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Quibod IL, Grande G, Oreiro EG, Borja FN, Dossa GS, Mauleon R, Cruz CV, Oliva R. Rice-Infecting Pseudomonas Genomes Are Highly Accessorized and Harbor Multiple Putative Virulence Mechanisms to Cause Sheath Brown Rot. PLoS One 2015; 10:e0139256. [PMID: 26422147 PMCID: PMC4589537 DOI: 10.1371/journal.pone.0139256] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 09/09/2015] [Indexed: 12/26/2022] Open
Abstract
Sheath rot complex and seed discoloration in rice involve a number of pathogenic bacteria that cannot be associated with distinctive symptoms. These pathogens can easily travel on asymptomatic seeds and therefore represent a threat to rice cropping systems. Among the rice-infecting Pseudomonas, P. fuscovaginae has been associated with sheath brown rot disease in several rice growing areas around the world. The appearance of a similar Pseudomonas population, which here we named P. fuscovaginae-like, represents a perfect opportunity to understand common genomic features that can explain the infection mechanism in rice. We showed that the novel population is indeed closely related to P. fuscovaginae. A comparative genomics approach on eight rice-infecting Pseudomonas revealed heterogeneous genomes and a high number of strain-specific genes. The genomes of P. fuscovaginae-like harbor four secretion systems (Type I, II, III, and VI) and other important pathogenicity machinery that could probably facilitate rice colonization. We identified 123 core secreted proteins, most of which have strong signatures of positive selection suggesting functional adaptation. Transcript accumulation of putative pathogenicity-related genes during rice colonization revealed a concerted virulence mechanism. The study suggests that rice-infecting Pseudomonas causing sheath brown rot are intrinsically diverse and maintain a variable set of metabolic capabilities as a potential strategy to occupy a range of environments.
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Affiliation(s)
- Ian Lorenzo Quibod
- Plant Breeding, Genetics, and Biotechnology Division, International Rice Research Institute, Los Baños, Philippines
| | - Genelou Grande
- Plant Breeding, Genetics, and Biotechnology Division, International Rice Research Institute, Los Baños, Philippines
| | - Eula Gems Oreiro
- Plant Breeding, Genetics, and Biotechnology Division, International Rice Research Institute, Los Baños, Philippines
| | - Frances Nikki Borja
- T.T. Chang- Genetic Resources Center, International Rice Research Institute, Los Baños, Philippines
| | - Gerbert Sylvestre Dossa
- Plant Breeding, Genetics, and Biotechnology Division, International Rice Research Institute, Los Baños, Philippines
- Department of Phytomedicine, Leibniz Universität Hannover, Hannover, Germany
| | - Ramil Mauleon
- T.T. Chang- Genetic Resources Center, International Rice Research Institute, Los Baños, Philippines
| | - Casiana Vera Cruz
- Plant Breeding, Genetics, and Biotechnology Division, International Rice Research Institute, Los Baños, Philippines
| | - Ricardo Oliva
- Plant Breeding, Genetics, and Biotechnology Division, International Rice Research Institute, Los Baños, Philippines
- * E-mail:
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Mao YH, Ma JC, Li F, Hu Z, Wang HH. Ralstonia solanacearum RSp0194 Encodes a Novel 3-Keto-Acyl Carrier Protein Synthase III. PLoS One 2015; 10:e0136261. [PMID: 26305336 PMCID: PMC4549310 DOI: 10.1371/journal.pone.0136261] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 08/03/2015] [Indexed: 11/18/2022] Open
Abstract
Fatty acid synthesis (FAS), a primary metabolic pathway, is essential for survival of bacteria. Ralstonia solanacearum, a β-proteobacteria member, causes a bacterial wilt affecting more than 200 plant species, including many economically important plants. However, thus far, the fatty acid biosynthesis pathway of R. solanacearum has not been well studied. In this study, we characterized two forms of 3-keto-ACP synthase III, RsFabH and RsFabW, in R. solanacearum. RsFabH, the homologue of Escherichia coli FabH, encoded by the chromosomal RSc1050 gene, catalyzes the condensation of acetyl-CoA with malonyl-ACP in the initiation steps of fatty acid biosynthesis in vitro. The RsfabH mutant lost de novo fatty acid synthetic ability, and grows in medium containing free fatty acids. RsFabW, a homologue of Pseudomonas aeruginosa PA3286, encoded by a megaplasmid gene, RSp0194, condenses acyl-CoA (C2-CoA to C10-CoA) with malonyl-ACP to produce 3-keto-acyl-ACP in vitro. Although the RsfabW mutant was viable, RsfabW was responsible for RsfabH mutant growth on medium containing free fatty acids. Our results also showed that RsFabW could condense acyl-ACP (C4-ACP to C8-ACP) with malonyl-ACP, to produce 3-keto-acyl-ACP in vitro, which implies that RsFabW plays a special role in fatty acid synthesis of R. solanacearum. All of these data confirm that R. solanacearum not only utilizes acetyl-CoA, but also, utilizes medium-chain acyl-CoAs or acyl-ACPs as primers to initiate fatty acid synthesis.
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Affiliation(s)
- Ya-Hui Mao
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Jin-Cheng Ma
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Feng Li
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Zhe Hu
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong 510642, China
| | - Hai-Hong Wang
- Guangdong Provincial Key Laboratory of Protein Function and Regulation in Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong 510642, China
- * E-mail:
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Jacobs JM, Pesce C, Lefeuvre P, Koebnik R. Comparative genomics of a cannabis pathogen reveals insight into the evolution of pathogenicity in Xanthomonas. FRONTIERS IN PLANT SCIENCE 2015; 6:431. [PMID: 26136759 DOI: 10.3389/fpls.2015.00431.ecollection2015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 05/27/2015] [Indexed: 05/24/2023]
Abstract
Pathogenic bacteria in the genus Xanthomonas cause diseases on over 350 plant species, including cannabis (Cannabis sativa L.). Because of regulatory limitations, the biology of the Xanthomonas-cannabis pathosystem remains largely unexplored. To gain insight into the evolution of Xanthomonas strains pathogenic to cannabis, we sequenced the genomes of two geographically distinct Xanthomonas strains, NCPPB 3753 and NCPPB 2877, which were previously isolated from symptomatic plant tissue in Japan and Romania. Comparative multilocus sequence analysis of housekeeping genes revealed that they belong to Group 2, which comprises most of the described species of Xanthomonas. Interestingly, both strains lack the Hrp Type III secretion system and do not contain any of the known Type III effectors. Yet their genomes notably encode two key Hrp pathogenicity regulators HrpG and HrpX, and hrpG and hrpX are in the same genetic organization as in the other Group 2 xanthomonads. Promoter prediction of HrpX-regulated genes suggests the induction of an aminopeptidase, a lipase and two polygalacturonases upon plant colonization, similar to other plant-pathogenic xanthomonads. Genome analysis of the distantly related Xanthomonas maliensis strain 97M, which was isolated from a rice leaf in Mali, similarly demonstrated the presence of HrpG, HrpX, and a HrpX-regulated polygalacturonase, and the absence of the Hrp Type III secretion system and known Type III effectors. Given the observation that some Xanthomonas strains across distinct taxa do not contain hrpG and hrpX, we speculate a stepwise evolution of pathogenicity, which involves (i) acquisition of key regulatory genes and cell wall-degrading enzymes, followed by (ii) acquisition of the Hrp Type III secretion system, which is ultimately accompanied by (iii) successive acquisition of Type III effectors.
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Affiliation(s)
- Jonathan M Jacobs
- Institut de Recherche pour le Développement - Cirad - Université Montpellier, Interactions Plantes Microorganismes Environnement Montpellier, France
| | - Céline Pesce
- Institut de Recherche pour le Développement - Cirad - Université Montpellier, Interactions Plantes Microorganismes Environnement Montpellier, France ; Department of Applied Microbiology, Earth and Life Institute, Université Catholique de Louvain Louvain-la-Neuve, Belgium
| | - Pierre Lefeuvre
- Pôle de Protection des Plantes, Cirad, UMR Peuplements Végétaux et Bioagresseurs en Milieu Tropical Saint-Pierre, Ile de la Réunion, France
| | - Ralf Koebnik
- Institut de Recherche pour le Développement - Cirad - Université Montpellier, Interactions Plantes Microorganismes Environnement Montpellier, France
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Song Z, Zhao Y, Zhou X, Wu G, Zhang Y, Qian G, Liu F. Identification and Characterization of Two Novel DSF-Controlled Virulence-Associated Genes Within the nodB-rhgB Locus of Xanthomonas oryzae pv. oryzicola Rs105. PHYTOPATHOLOGY 2015; 105:588-596. [PMID: 26020828 DOI: 10.1094/phyto-07-14-0190-r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Xanthomonas oryzae pv. oryzicola and X. oryzae pv. oryzae are two pathovars of X. oryzae that cause leaf streak and blight in rice, respectively. These two bacterial pathogens cause different disease symptoms by utilizing different infection sites on rice. Compared with X. oryzae pv. oryzae, the molecular virulence mechanism of X. oryzae pv. oryzicola remains largely unknown. Previously, we identified a unique diffusible signal factor (DSF)-controlled virulence-related gene (hshB) in X. oryzae pv. oryzicola Rs105 located in the nodB-rghB locus, which is absent in X. oryzae pv. oryzae PXO99(A). In the present study, we identified two additional genes within this locus (hshA and hshC) that were unique to X. oryzae pv. oryzicola Rs105 compared with X. oryzae pv. oryzae PXO99(A), and we found that the transcription of these genes was regulated by DSF signaling in X. oryzae pv. oryzicola. The mutation of these genes impaired the virulence of the wild-type Rs105 when using a low inoculation density of X. oryzae pv. oryzicola. In contrast to hshB, the mutation of these genes did not have any visible effect on characterized virulence-related functions, including in vitro growth, extracellular polysaccharide production, extracellular protease activity, and antioxidative ability. However, we found that mutation of hshA or hshC significantly reduced the in planta growth ability and epiphytic survival level of X. oryzae pv. oryzicola cells, which was the probable mechanisms of involvement of these two genes in virulence. Collectively, our studies of X. oryzae pv. oryzicola have identified two novel DSF-controlled virulence-associated genes (hshA and hshC), which will add to our understanding of the regulatory mechanisms of conserved DSF virulence signaling in Xanthomonas species.
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Affiliation(s)
- Zhiwei Song
- First, third, fourth, fifth, sixth, and seventh authors: College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China/Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education, China; and second and seventh authors: Institute of Plant Protection, Jiangsu Academy of Agricultural Science, Nanjing 210014, P.R. China
| | - Yancun Zhao
- First, third, fourth, fifth, sixth, and seventh authors: College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China/Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education, China; and second and seventh authors: Institute of Plant Protection, Jiangsu Academy of Agricultural Science, Nanjing 210014, P.R. China
| | - Xingyang Zhou
- First, third, fourth, fifth, sixth, and seventh authors: College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China/Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education, China; and second and seventh authors: Institute of Plant Protection, Jiangsu Academy of Agricultural Science, Nanjing 210014, P.R. China
| | - Guichun Wu
- First, third, fourth, fifth, sixth, and seventh authors: College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China/Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education, China; and second and seventh authors: Institute of Plant Protection, Jiangsu Academy of Agricultural Science, Nanjing 210014, P.R. China
| | - Yuqiang Zhang
- First, third, fourth, fifth, sixth, and seventh authors: College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China/Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education, China; and second and seventh authors: Institute of Plant Protection, Jiangsu Academy of Agricultural Science, Nanjing 210014, P.R. China
| | - Guoliang Qian
- First, third, fourth, fifth, sixth, and seventh authors: College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China/Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education, China; and second and seventh authors: Institute of Plant Protection, Jiangsu Academy of Agricultural Science, Nanjing 210014, P.R. China
| | - Fengquan Liu
- First, third, fourth, fifth, sixth, and seventh authors: College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China/Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education, China; and second and seventh authors: Institute of Plant Protection, Jiangsu Academy of Agricultural Science, Nanjing 210014, P.R. China
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Holtappels M, Vrancken K, Schoofs H, Deckers T, Remans T, Noben JP, Valcke R. A comparative proteome analysis reveals flagellin, chemotaxis regulated proteins and amylovoran to be involved in virulence differences between Erwinia amylovora strains. J Proteomics 2015; 123:54-69. [PMID: 25849252 DOI: 10.1016/j.jprot.2015.03.036] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Revised: 03/07/2015] [Accepted: 03/31/2015] [Indexed: 12/16/2022]
Abstract
UNLABELLED Erwinia amylovora is a Gram-negative bacterium that causes the destructive disease fire blight affecting most members of the Rosaceae family, of which apple and pear are economically the most important hosts. E. amylovora has been considered as a homogeneous species in whole, although significant differences in virulence patterns have been observed. However, the underlying causes of the differences in virulence remain to be discovered. In a first-time comparative proteomic approach using E. amylovora, 2D differential in-gel electrophoresis (DIGE) was used to identify proteins that could explain the gradual difference in virulence between four different strains. Two important proteins were identified, FliC and CheY, both involved in flagella structure, motility and chemotaxis, which were more abundant in the least virulent strain. In the highly virulent strains the protein GalF, involved in amylovoran production, was more abundant, which was consistent with the higher expression of the gene and the higher amylovoran content in this strain in vitro. Together, these results confirm the involvement of amylovoran in virulence, but also imply an indirect role of flagellin in virulence as elicitor of plant defence. BIOLOGICAL SIGNIFICANCE This research provides new insights into our current understanding of the virulence of Erwinia amylovora. This plant-pathogen is considered a homogeneous species although different strains show differences in virulence. Despite the efforts made on the genomic level which resulted in the discovery of virulence factors, the reason for the different virulence patterns between strains has not yet been identified. In our lab we used a comparative proteomic approach, which has never been published before, to identify proteins involved in these differences between strains and hereby possibly involved in virulence. Our results provide interesting insights in virulence and present us with the opportunity to glance into the proteome of E. amylovora.
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Affiliation(s)
- M Holtappels
- Molecular and Physical Plant Physiology, Faculty of Sciences, Hasselt University, Agoralaan Building D, 3590 Diepenbeek, Belgium
| | - K Vrancken
- Zoology Department, PCFruit Research Station, Fruittuinweg 1, 3800 Sint-Truiden, Belgium
| | - H Schoofs
- Pomology Department, PCFruit Research Station, Fruittuinweg 1, 3800 Sint-Truiden, Belgium
| | - T Deckers
- Pomology Department, PCFruit Research Station, Fruittuinweg 1, 3800 Sint-Truiden, Belgium
| | - T Remans
- Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, 3590 Diepenbeek, Belgium
| | - J P Noben
- Biomedical Research Institute, Hasselt University and Transnational University Limburg, School of Life Sciences, Hasselt, Belgium
| | - R Valcke
- Molecular and Physical Plant Physiology, Faculty of Sciences, Hasselt University, Agoralaan Building D, 3590 Diepenbeek, Belgium.
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Li B, Wang L, Ibrahim M, Ge M, Wang Y, Mannan S, Asif M, Sun G. Membrane protein profiling of Acidovorax avenae subsp. avenae under various growth conditions. Arch Microbiol 2015; 197:673-82. [PMID: 25763989 DOI: 10.1007/s00203-015-1100-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 02/01/2015] [Accepted: 03/02/2015] [Indexed: 10/23/2022]
Abstract
Membrane proteins (MPs) of plant pathogenic bacteria have been reported to be able to regulate many essential cellular processes associated with plant disease. The aim of the current study was to examine and compare the expression of MPs of the rice bacterial pathogen Acidovorax avenae subsp. avenae strain RS-1 under Luria-Bertani (LB) medium, M9 medium, in vivo rice plant conditions and leaf extract (LE) medium mimicking in vivo plant condition. Proteomic analysis identified 95, 72, 75, and 87 MPs under LB, in vivo, M9 and LE conditions, respectively. Among them, six proteins were shared under all tested growth conditions designated as abundant class of proteins. Twenty-six and 21 proteins were expressed uniquely under in vivo versus LB medium and LE versus M9 medium, respectively, with 17 proteins common among these uniquely induced proteins. Moreover, most of the shared proteins are mainly related to energy metabolism, transport of small molecules, protein synthesis and secretion as well as virulence such as NADH, OmpA, secretion proteins. Therefore, the result of this study not only suggests that it may be an alternate method to analyze the in vivo expression of proteins by using LE medium to mimic plant conditions, but also reveals that the two sets of differentially expressed MPs, in particular the common MPs between them, might be important in energy metabolism, stress response and virulence of A. avenae subsp. avenae strain RS-1.
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Affiliation(s)
- Bin Li
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, 310058, China,
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Etesami H, Alikhani HA, Mirseyed Hosseini H. Indole-3-Acetic Acid and 1-Aminocyclopropane-1-Carboxylate Deaminase: Bacterial Traits Required in Rhizosphere, Rhizoplane and/or Endophytic Competence by Beneficial Bacteria. BACTERIAL METABOLITES IN SUSTAINABLE AGROECOSYSTEM 2015. [DOI: 10.1007/978-3-319-24654-3_8] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Fu SF, Wei JY, Chen HW, Liu YY, Lu HY, Chou JY. Indole-3-acetic acid: A widespread physiological code in interactions of fungi with other organisms. PLANT SIGNALING & BEHAVIOR 2015; 10:e1048052. [PMID: 26179718 PMCID: PMC4623019 DOI: 10.1080/15592324.2015.1048052] [Citation(s) in RCA: 126] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 04/30/2015] [Accepted: 04/30/2015] [Indexed: 05/20/2023]
Abstract
Plants as well as microorganisms, including bacteria and fungi, produce indole-3-acetic acid (IAA). IAA is the most common plant hormone of the auxin class and it regulates various aspects of plant growth and development. Thus, research is underway globally to exploit the potential for developing IAA-producing fungi for promoting plant growth and protection for sustainable agriculture. Phylogenetic evidence suggests that IAA biosynthesis evolved independently in bacteria, microalgae, fungi, and plants. Present studies show that IAA regulates the physiological response and gene expression in these microorganisms. The convergent evolution of IAA production leads to the hypothesis that natural selection might have favored IAA as a widespread physiological code in these microorganisms and their interactions. We summarize recent studies of IAA biosynthetic pathways and discuss the role of IAA in fungal ecology.
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Affiliation(s)
- Shih-Feng Fu
- Department of Biology; National Changhua University of Education; Taiwan, R.O.C
| | - Jyuan-Yu Wei
- Department of Biology; National Changhua University of Education; Taiwan, R.O.C
| | - Hung-Wei Chen
- Department of Biology; National Changhua University of Education; Taiwan, R.O.C
| | - Yen-Yu Liu
- Department of Biology; National Changhua University of Education; Taiwan, R.O.C
| | - Hsueh-Yu Lu
- Department of Biology; National Changhua University of Education; Taiwan, R.O.C
| | - Jui-Yu Chou
- Department of Biology; National Changhua University of Education; Taiwan, R.O.C
- Correspondence to: Jui-Yu Chou;
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Jacobs JM, Pesce C, Lefeuvre P, Koebnik R. Comparative genomics of a cannabis pathogen reveals insight into the evolution of pathogenicity in Xanthomonas. FRONTIERS IN PLANT SCIENCE 2015; 6:431. [PMID: 26136759 PMCID: PMC4468381 DOI: 10.3389/fpls.2015.00431] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 05/27/2015] [Indexed: 05/05/2023]
Abstract
Pathogenic bacteria in the genus Xanthomonas cause diseases on over 350 plant species, including cannabis (Cannabis sativa L.). Because of regulatory limitations, the biology of the Xanthomonas-cannabis pathosystem remains largely unexplored. To gain insight into the evolution of Xanthomonas strains pathogenic to cannabis, we sequenced the genomes of two geographically distinct Xanthomonas strains, NCPPB 3753 and NCPPB 2877, which were previously isolated from symptomatic plant tissue in Japan and Romania. Comparative multilocus sequence analysis of housekeeping genes revealed that they belong to Group 2, which comprises most of the described species of Xanthomonas. Interestingly, both strains lack the Hrp Type III secretion system and do not contain any of the known Type III effectors. Yet their genomes notably encode two key Hrp pathogenicity regulators HrpG and HrpX, and hrpG and hrpX are in the same genetic organization as in the other Group 2 xanthomonads. Promoter prediction of HrpX-regulated genes suggests the induction of an aminopeptidase, a lipase and two polygalacturonases upon plant colonization, similar to other plant-pathogenic xanthomonads. Genome analysis of the distantly related Xanthomonas maliensis strain 97M, which was isolated from a rice leaf in Mali, similarly demonstrated the presence of HrpG, HrpX, and a HrpX-regulated polygalacturonase, and the absence of the Hrp Type III secretion system and known Type III effectors. Given the observation that some Xanthomonas strains across distinct taxa do not contain hrpG and hrpX, we speculate a stepwise evolution of pathogenicity, which involves (i) acquisition of key regulatory genes and cell wall-degrading enzymes, followed by (ii) acquisition of the Hrp Type III secretion system, which is ultimately accompanied by (iii) successive acquisition of Type III effectors.
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Affiliation(s)
- Jonathan M. Jacobs
- Institut de Recherche pour le Développement – Cirad – Université Montpellier, Interactions Plantes Microorganismes EnvironnementMontpellier, France
| | - Céline Pesce
- Institut de Recherche pour le Développement – Cirad – Université Montpellier, Interactions Plantes Microorganismes EnvironnementMontpellier, France
- Department of Applied Microbiology, Earth and Life Institute, Université Catholique de LouvainLouvain-la-Neuve, Belgium
| | - Pierre Lefeuvre
- Pôle de Protection des Plantes, Cirad, UMR Peuplements Végétaux et Bioagresseurs en Milieu TropicalSaint-Pierre, Ile de la Réunion, France
| | - Ralf Koebnik
- Institut de Recherche pour le Développement – Cirad – Université Montpellier, Interactions Plantes Microorganismes EnvironnementMontpellier, France
- *Correspondence: Ralf Koebnik, Institut de Recherche pour le Développement, UMR Interactions – Plantes – Microorganismes – Environnement, Génomique et Transcriptomique des Interactions Plantes-Procaryotes, 921 avenue Agropolis, 34394 Montpellier, France
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Uzum Z, Silipo A, Lackner G, De Felice A, Molinaro A, Hertweck C. Structure, Genetics and Function of an Exopolysaccharide Produced by a Bacterium Living within Fungal Hyphae. Chembiochem 2014; 16:387-92. [DOI: 10.1002/cbic.201402488] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Indexed: 11/08/2022]
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Andrade MO, Farah CS, Wang N. The post-transcriptional regulator rsmA/csrA activates T3SS by stabilizing the 5' UTR of hrpG, the master regulator of hrp/hrc genes, in Xanthomonas. PLoS Pathog 2014; 10:e1003945. [PMID: 24586158 PMCID: PMC3937308 DOI: 10.1371/journal.ppat.1003945] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 01/09/2014] [Indexed: 11/28/2022] Open
Abstract
The RsmA/CsrA family of the post-transcriptional regulators of bacteria is involved in the regulation of many cellular processes, including pathogenesis. In this study, we demonstrated that rsmA not only is required for the full virulence of the phytopathogenic bacterium Xanthomonas citri subsp. citri (XCC) but also contributes to triggering the hypersensitive response (HR) in non-host plants. Deletion of rsmA resulted in significantly reduced virulence in the host plant sweet orange and a delayed and weakened HR in the non-host plant Nicotiana benthamiana. Microarray, quantitative reverse-transcription PCR, western-blotting, and GUS assays indicated that RsmA regulates the expression of the type 3 secretion system (T3SS) at both transcriptional and post-transcriptional levels. The regulation of T3SS by RsmA is a universal phenomenon in T3SS-containing bacteria, but the specific mechanism seems to depend on the interaction between a particular bacterium and its hosts. For Xanthomonads, the mechanism by which RsmA activates T3SS remains unknown. Here, we show that RsmA activates the expression of T3SS-encoding hrp/hrc genes by directly binding to the 5′ untranslated region (UTR) of hrpG, the master regulator of the hrp/hrc genes in XCC. RsmA stabilizes hrpG mRNA, leading to increased accumulation of HrpG proteins and subsequently, the activation of hrp/hrc genes. The activation of the hrp/hrc genes by RsmA via HrpG was further supported by the observation that ectopic overexpression of hrpG in an rsmA mutant restored its ability to cause disease in host plants and trigger HR in non-host plants. RsmA also stabilizes the transcripts of another T3SS-associated hrpD operon by directly binding to the 5′ UTR region. Taken together, these data revealed that RsmA primarily activates T3SS by acting as a positive regulator of hrpG and that this regulation is critical to the pathogenicity of XCC. Pathogenic bacteria demonstrate sophisticated capacity to regulate gene expression to meet requirements of living in different environmental niches, including in the hosts. The activation of the Type 3 secretion system (T3SS) genes in response to the host enviroment is under the control of several factors, such as the post-transcriptional regulator RsmA/CsrA. Here, we show that RsmA contributes to the pathogenicity of Xanthomonas citri in host plants and the HR-triggering activity in non-host plants by regulating the expression of T3SS-encoding hrp/hrc genes. RsmA directly interacts with the 5′ UTRs of hrpG and hrpD mRNAs, which leads to increased HrpG protein levels by stabilizing the hrpG transcript. Further, overexpression of hrpG in an rsmA mutant restored its pathogenicity and ability to cause HR. The deletion of rsmA did not affect the phosphorylation of HrpG, which is also required for T3SS activation. This work provides mechanistic insights for the first time into RsmA-mediated regulation of T3SS gene expression by acting as a positive regulator of hrpG at the post-transcription level.
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Affiliation(s)
- Maxuel O. Andrade
- Citrus Research and Education Center, Department of Microbiology and Cell Sciences, University of Florida, Lake Alfred, Florida, United States of America
| | - Chuck S. Farah
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, São Paulo, Brazil
| | - Nian Wang
- Citrus Research and Education Center, Department of Microbiology and Cell Sciences, University of Florida, Lake Alfred, Florida, United States of America
- * E-mail:
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Zuluaga AP, Puigvert M, Valls M. Novel plant inputs influencing Ralstonia solanacearum during infection. Front Microbiol 2013; 4:349. [PMID: 24312090 PMCID: PMC3834233 DOI: 10.3389/fmicb.2013.00349] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Accepted: 11/04/2013] [Indexed: 11/17/2022] Open
Abstract
Ralstonia solanacearum is a soil and water-borne pathogen that can infect a wide range of plants and cause the devastating bacterial wilt disease. To successfully colonize a host, R. solanacearum requires the type III secretion system (T3SS), which delivers bacterial effector proteins inside the plant cells. HrpG is a central transcriptional regulator that drives the expression of the T3SS and other virulence determinants. hrpG transcription is highly induced upon plant cell contact and its product is also post-transcriptionally activated by metabolic signals present when bacteria are grown in minimal medium (MM). Here, we describe a transcriptional induction of hrpG at early stages of bacterial co-culture with plant cells that caused overexpression of the downstream T3SS effector genes. This induction was maintained in a strain devoid of prhA, the outer membrane receptor that senses bacterial contact with plant cells, demonstrating that this is a response to an unknown signal. Induction was unaffected after disruption of the known R. solanacearum pathogenicity regulators, indicating that it is controlled by a non-described system. Moreover, plant contact-independent signals are also important in planta, as shown by the hrpG induction triggered by apoplastic and xylem extracts. We also found that none of the amino acids or sugars present in the apoplast and xylem saps studied correlated with hrpG induction. This suggests that a small molecule or an environmental condition is responsible for the T3SS gene expression inside the plants. Our results also highlight the abundance and diversity of possible carbon, nitrogen and energy sources likely used by R. solanacearum during growth in planta.
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Affiliation(s)
- A Paola Zuluaga
- Departament de Genètica, Universitat de Barcelona Barcelona, Spain ; Centre for Research in Agricultural Genomics (CSIC-IRTA-UB-UAB) Bellaterra, Spain
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