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Klepa MS, diCenzo GC, Hungria M. Comparative genomic analysis of Bradyrhizobium strains with natural variability in the efficiency of nitrogen fixation, competitiveness, and adaptation to stressful edaphoclimatic conditions. Microbiol Spectr 2024:e0026024. [PMID: 38842312 DOI: 10.1128/spectrum.00260-24] [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: 01/28/2024] [Accepted: 05/01/2024] [Indexed: 06/07/2024] Open
Abstract
Bradyrhizobium is known for fixing atmospheric nitrogen in symbiosis with agronomically important crops. This study focused on two groups of strains, each containing eight natural variants of the parental strains, Bradyrhizobium japonicum SEMIA 586 (=CNPSo 17) or Bradyrhizobium diazoefficiens SEMIA 566 (=CNPSo 10). CNPSo 17 and CNPSo 10 were used as commercial inoculants for soybean crops in Brazil at the beginning of the crop expansion in the southern region in the 1960s-1970s. Variants derived from these parental strains were obtained in the late 1980s through a strain selection program aimed at identifying elite strains adapted to a new cropping frontier in the central-western Cerrado region, with a higher capacity of biological nitrogen fixation (BNF) and competitiveness. Here, we aimed to detect genetic variations possibly related to BNF, competitiveness for nodule occupancy, and adaptation to the stressful conditions of the Brazilian Cerrado soils. High-quality genome assemblies were produced for all strains. The core genome phylogeny revealed that strains of each group are closely related, as confirmed by high average nucleotide identity values. However, variants accumulated divergences resulting from horizontal gene transfer, genomic rearrangements, and nucleotide polymorphisms. The B. japonicum group presented a larger pangenome and a higher number of nucleotide polymorphisms than the B. diazoefficiens group, possibly due to its longer adaptation time to the Cerrado soil. Interestingly, five strains of the B. japonicum group carry two plasmids. The genetic variability found in both groups is discussed considering the observed differences in their BNF capacity, competitiveness for nodule occupancy, and environmental adaptation.IMPORTANCEToday, Brazil is a global leader in the study and use of biological nitrogen fixation with soybean crops. As Brazilian soils are naturally void of soybean-compatible bradyrhizobia, strain selection programs were established, starting with foreign isolates. Selection searched for adaptation to the local edaphoclimatic conditions, higher efficiency of nitrogen fixation, and strong competitiveness for nodule occupancy. We analyzed the genomes of two parental strains of Bradyrhizobium japonicum and Bradyrhizobium diazoefficiens and eight variant strains derived from each parental strain. We detected two plasmids in five strains and several genetic differences that might be related to adaptation to the stressful conditions of the soils of the Brazilian Cerrado biome. We also detected genetic variations in specific regions that may impact symbiotic nitrogen fixation. Our analysis contributes to new insights into the evolution of Bradyrhizobium, and some of the identified differences may be applied as genetic markers to assist strain selection programs.
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Affiliation(s)
- Milena Serenato Klepa
- Soil Biotechnology Laboratory, Embrapa Soja, Londrina, Paraná, Brazil
- CNPq, Brasília, Brazil
| | | | - Mariangela Hungria
- Soil Biotechnology Laboratory, Embrapa Soja, Londrina, Paraná, Brazil
- CNPq, Brasília, Brazil
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2
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Nievas F, Revale S, Cossovich S, Foresto E, Carezzano ME, Alzari P, Martínez M, Ben-Assaya M, Mornico D, Santoro M, Martínez-Abarca F, Giordano W, Bogino P. Complete genome sequence of Bradyrhizobium sp. 62B, a native nitrogen-fixing rhizobium isolated from peanut nodules. Microbiol Resour Announc 2024; 13:e0092823. [PMID: 38385707 DOI: 10.1128/mra.00928-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Accepted: 02/13/2024] [Indexed: 02/23/2024] Open
Abstract
We present the complete genome sequence of Bradyrhizobium sp. 62B, a strain isolated from the root nodules of peanut plants that grow in central Argentina. The genome consists of 8.15 Mbp, distributed into a chromosome of 7.29 Mbp and a plasmid of 0.86 Mbp.
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Affiliation(s)
- Fiorela Nievas
- Departamento de Biología Molecular, Instituto de Biotecnología Ambiental y Salud (INBIAS-CONICET), Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba, Argentina
| | - Santiago Revale
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Sacha Cossovich
- Departamento de Biología Molecular, Instituto de Biotecnología Ambiental y Salud (INBIAS-CONICET), Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba, Argentina
| | - Emiliano Foresto
- Departamento de Biología Molecular, Instituto de Biotecnología Ambiental y Salud (INBIAS-CONICET), Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba, Argentina
| | - María Evangelina Carezzano
- Departamento de Biología Molecular, Instituto de Biotecnología Ambiental y Salud (INBIAS-CONICET), Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba, Argentina
| | - Pedro Alzari
- Unité de Microbiologie Structurale, Institut Pasteur, CNRS UMR 3528, Université de Paris, Paris, France
| | - Mariano Martínez
- Unité de Microbiologie Structurale, Institut Pasteur, CNRS UMR 3528, Université de Paris, Paris, France
| | - Mathilde Ben-Assaya
- Unité de Microbiologie Structurale, Institut Pasteur, CNRS UMR 3528, Université de Paris, Paris, France
| | - Damien Mornico
- Hub de Bioinformatique et Biostatistique - Département Biologie Computationnelle, Institut Pasteur, Paris, France
| | - Maricel Santoro
- Department of Biochemistry, Max Planck for Chemical Ecology, Jena, Germany
| | - Francisco Martínez-Abarca
- Department of Plant and Soil Microbiology, Structure, Dynamics, and Function of Rhizobacterial Genomes, Estación Experimental del Zaidín-CSIC, Granada, Spain
| | - Walter Giordano
- Departamento de Biología Molecular, Instituto de Biotecnología Ambiental y Salud (INBIAS-CONICET), Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba, Argentina
| | - Pablo Bogino
- Departamento de Biología Molecular, Instituto de Biotecnología Ambiental y Salud (INBIAS-CONICET), Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba, Argentina
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3
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Hooykaas PJJ. The Ti Plasmid, Driver of Agrobacterium Pathogenesis. PHYTOPATHOLOGY 2023; 113:594-604. [PMID: 37098885 DOI: 10.1094/phyto-11-22-0432-ia] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The phytopathogenic bacterium Agrobacterium tumefaciens causes crown gall disease in plants, characterized by the formation of tumor-like galls where wounds were present. Nowadays, however, the bacterium and its Ti (tumor-inducing) plasmid is better known as an effective vector for the genetic manipulation of plants and fungi. In this review, I will briefly summarize some of the major discoveries that have led to this bacterium now playing such a prominent role worldwide in plant and fungal research at universities and research institutes and in agricultural biotechnology for the production of genetically modified crops. I will then delve a little deeper into some aspects of Agrobacterium biology and discuss the diversity among agrobacteria and the taxonomic position of these bacteria, the diversity in Ti plasmids, the molecular mechanism used by the bacteria to transform plants, and the discovery of protein translocation from the bacteria to host cells as an essential feature of Agrobacterium-mediated transformation.
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4
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Luchetti A, Castellani LG, Toscani AM, Lagares A, Del Papa MF, Torres Tejerizo G, Pistorio M. Characterization of an accessory plasmid of Sinorhizobium meliloti and its two replication-modules. PLoS One 2023; 18:e0285505. [PMID: 37200389 DOI: 10.1371/journal.pone.0285505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 04/25/2023] [Indexed: 05/20/2023] Open
Abstract
Rhizobia are Gram-negative bacteria known for their ability to fix atmospheric N2 in symbiosis with leguminous plants. Current evidence shows that rhizobia carry in most cases a variable number of plasmids, containing genes necessary for symbiosis or free-living, a common feature being the presence of several plasmid replicons within the same strain. For many years, we have been studying the mobilization properties of pSmeLPU88b from the strain Sinorhizobium meliloti LPU88, an isolate from Argentina. To advance in the characterization of pSmeLPU88b plasmid, the full sequence was obtained. pSmeLPU88b is 35.9 kb in size, had an average GC % of 58.6 and 31 CDS. Two replication modules were identified in silico: one belonging to the repABC type, and the other to the repC. The replication modules presented high DNA identity to the replication modules from plasmid pMBA9a present in an S. meliloti isolate from Canada. In addition, three CDS presenting identity with recombinases and with toxin-antitoxin systems were found downstream of the repABC system. It is noteworthy that these CDS present the same genetic structure in pSmeLPU88b and in other rhizobial plasmids. Moreover, in all cases they are found downstream of the repABC operon. By cloning each replication system in suicide plasmids, we demonstrated that each of them can support plasmid replication in the S. meliloti genetic background, but with different stability behavior. Interestingly, while incompatibility analysis of the cloned rep systems results in the loss of the parental module, both obtained plasmids can coexist together.
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Affiliation(s)
- Abril Luchetti
- Proteome and Metabolome Research, Faculty of Biology, Center for Biotechnology, Bielefeld University, Bielefeld, Germany
- Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, IBBM (Instituto de Biotecnología y Biología Molecular), CCT-CONICET-La Plata, Universidad Nacional de La Plata, La Plata, Argentina
| | - Lucas G Castellani
- Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, IBBM (Instituto de Biotecnología y Biología Molecular), CCT-CONICET-La Plata, Universidad Nacional de La Plata, La Plata, Argentina
| | - Andrés Martin Toscani
- Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, IBBM (Instituto de Biotecnología y Biología Molecular), CCT-CONICET-La Plata, Universidad Nacional de La Plata, La Plata, Argentina
| | - Antonio Lagares
- Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, IBBM (Instituto de Biotecnología y Biología Molecular), CCT-CONICET-La Plata, Universidad Nacional de La Plata, La Plata, Argentina
| | - María Florencia Del Papa
- Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, IBBM (Instituto de Biotecnología y Biología Molecular), CCT-CONICET-La Plata, Universidad Nacional de La Plata, La Plata, Argentina
| | - Gonzalo Torres Tejerizo
- Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, IBBM (Instituto de Biotecnología y Biología Molecular), CCT-CONICET-La Plata, Universidad Nacional de La Plata, La Plata, Argentina
| | - Mariano Pistorio
- Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, IBBM (Instituto de Biotecnología y Biología Molecular), CCT-CONICET-La Plata, Universidad Nacional de La Plata, La Plata, Argentina
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5
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The Sixth Element: a 102-kb RepABC Plasmid of Xenologous Origin Modulates Chromosomal Gene Expression in Dinoroseobacter shibae. mSystems 2022; 7:e0026422. [PMID: 35920548 PMCID: PMC9426580 DOI: 10.1128/msystems.00264-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The model organism Dinoroseobacter shibae and many other marine Rhodobacterales (Roseobacteraceae, Alphaproteobacteria) are characterized by a multipartite genome organization. Here, we show that the original isolate (Dshi-6) contained six extrachromosomal replicons (ECRs), whereas the strain deposited at the DSMZ (Dshi-5) lacked a 102-kb plasmid. To determine the role of the sixth plasmid, we investigated the genomic and physiological differences between the two strains. Therefore, both genomes were (re)sequenced, and gene expression, growth, and substrate utilization were examined. For comparison, we included additional plasmid-cured strains in the analysis. In the Dshi-6 population, the conjugative 102-kb RepABC-9 plasmid was present in only about 50% of the cells, irrespective of its experimentally validated stability. In the presence of the sixth plasmid, copy number changes of other ECRs, in particular, a decrease of the 86-kb plasmid, were observed. The most conspicuous finding was the strong influence of plasmids on chromosomal gene expression, especially the repression of the CtrA regulon and the activation of the denitrification gene cluster. Expression is inversely controlled by either the presence of the 102-kb plasmid or the absence of the 86-kb plasmid. We identified regulatory genes on both plasmids, i.e., a sigma 70 factor and a quorum sensing synthase, that might be responsible for these major changes. The tremendous effects that were probably even underestimated challenge the current understanding of the relevance of volatile plasmids not only for the original host but also for new recipients after conjugation. IMPORTANCE Plasmids are small DNA molecules that replicate independently of the bacterial chromosome. The common view of the role of plasmids is dominated by the accumulation of resistance genes, which is responsible for the antibiotic crisis in health care and livestock breeding. Beyond rapid adaptations to a changing environment, no general relevance for the host cell’s regulome was attributed to these volatile ECRs. The current study shows for the model organism D. shibae that its chromosomal gene expression is strongly influenced by two plasmids. We provide evidence that the gain or loss of plasmids not only results in minor alterations of the genetic repertoire but also can have tremendous effects on bacterial physiology. The central role of some plasmids in the regulatory network of the host could also explain their persistence despite fitness costs, which has been described as the “plasmid paradox.”
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Sackett JD, Kamble N, Leach E, Schuelke T, Wilbanks E, Rowe AR. Genome-Scale Mutational Analysis of Cathode-Oxidizing Thioclava electrotropha ElOx9 T. Front Microbiol 2022; 13:909824. [PMID: 35756027 PMCID: PMC9226611 DOI: 10.3389/fmicb.2022.909824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 05/17/2022] [Indexed: 11/13/2022] Open
Abstract
Extracellular electron transfer (EET) – the process by which microorganisms transfer electrons across their membrane(s) to/from solid-phase materials – has implications for a wide range of biogeochemically important processes in marine environments. Though EET is thought to play an important role in the oxidation of inorganic minerals by lithotrophic organisms, the mechanisms involved in the oxidation of solid particles are poorly understood. To explore the genetic basis of oxidative EET, we utilized genomic analyses and transposon insertion mutagenesis screens (Tn-seq) in the metabolically flexible, lithotrophic Alphaproteobacterium Thioclava electrotropha ElOx9T. The finished genome of this strain is 4.3 MB, and consists of 4,139 predicted ORFs, 54 contain heme binding motifs, and 33 of those 54 are predicted to localize to the cell envelope or have unknown localizations. To begin to understand the genetic basis of oxidative EET in ElOx9T, we constructed a transposon mutant library in semi-rich media which was comprised of >91,000 individual mutants encompassing >69,000 unique TA dinucleotide insertion sites. The library was subjected to heterotrophic growth on minimal media with acetate and autotrophic oxidative EET conditions on indium tin oxide coated glass electrodes poised at –278 mV vs. SHE or un-poised in an open circuit condition. We identified 528 genes classified as essential under these growth conditions. With respect to electrochemical conditions, 25 genes were essential under oxidative EET conditions, and 29 genes were essential in both the open circuit control and oxidative EET conditions. Though many of the genes identified under electrochemical conditions are predicted to be localized in the cytoplasm and lack heme binding motifs and/or homology to known EET proteins, we identified several hypothetical proteins and poorly characterized oxidoreductases that implicate a novel mechanism(s) for EET that warrants further study. Our results provide a starting point to explore the genetic basis of novel oxidative EET in this marine sediment microbe.
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Affiliation(s)
- Joshua D Sackett
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, United States
| | - Nitin Kamble
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, United States
| | - Edmund Leach
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, United States
| | - Taruna Schuelke
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Elizabeth Wilbanks
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Annette R Rowe
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, United States
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7
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Differential Localization and Functional Specialization of parS Centromere-Like Sites in repABC Replicons of Alphaproteobacteria. Appl Environ Microbiol 2022; 88:e0020722. [PMID: 35389251 PMCID: PMC9040568 DOI: 10.1128/aem.00207-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Partitioning systems ensure the stable inheritance of bacterial low-copy-number replicons, such as chromosomes, chromids, and megaplasmids. These loci consist of two genes encoding partition proteins A and B, and at least one parS centromere-like sequence. In chromids and megaplasmids, partitioning systems are often located in the vicinity of replication systems. An extreme example of this co-localization are alphaproteobacterial repABC replicons, where the partition (repAB) and replication (repC) genes form a single operon, with parS sequences usually positioned in close proximity to these genes. In this study, we characterized a more complex repABC system found in Paracoccus aminophilus (Rhodobacterales) megaplasmid pAMI4 (438 kb). Besides the repABC operon with a single parS site, this replicon has a 2-kb non-coding locus positioned 11.5 kb downstream of repC, which contains three additional parS repeats (3parS). We demonstrated that 3parS is bound by partition protein B in vitro and is essential for proper pAMI4 partitioning in vivo. In search of similar loci, we conducted a comparative analysis of parS distribution in other repABC replicons. This revealed different patterns of parS localization in Rhodobacterales and Rhizobiales. However, in both these taxonomic orders, parS sites are almost always located inside or close to the repABC operon. No other 3parS-like loci were found in the closest relatives of pAMI4. Another evolutionarily-independent example of such a locus was identified as a conserved feature in chromosome 2 of Allorhizobium vitis and related replicons. IMPORTANCE The repABC replication/partitioning loci are widespread in extrachromosomal replicons of Alphaproteobacteria. They are evolutionarily diverse, subject to multi-layer self-regulation, and are responsible for the maintenance of different types of replicons, such as plasmids (e.g., Agrobacterium pTi and pRi tumorigenic and rhizogenic plasmids), megaplasmids (e.g., Sinorhizobium pSymA and pSymB) and essential chromids (e.g., secondary chromosomes of Agrobacterium, Brucella and Rhodobacter). In this study, we functionally analyzed an atypical partition-related component of repABC systems, the 3parS locus, found in the P. aminophilus megaplasmid pAMI4. We also identified parS centromere-like site distribution patterns in different groups of repABC replicons and found other unrelated 3parS-like loci, which had been overlooked. Our findings raise questions concerning the biological reasons for differential parS distribution, which may reflect variations in repABC operon regulation as well as different replication and partition modes of replicons belonging to the repABC family.
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8
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Characterization of the Agrobacterium octopine-cucumopine catabolic plasmid pAtAg67. Plasmid 2022; 121:102629. [DOI: 10.1016/j.plasmid.2022.102629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 03/06/2022] [Accepted: 03/29/2022] [Indexed: 11/21/2022]
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9
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Herbert A, Hancock CN, Cox B, Schnabel G, Moreno D, Carvalho R, Jones J, Paret M, Geng X, Wang H. Oxytetracycline and Streptomycin Resistance Genes in Xanthomonas arboricola pv. pruni, the Causal Agent of Bacterial Spot in Peach. Front Microbiol 2022; 13:821808. [PMID: 35283838 PMCID: PMC8914263 DOI: 10.3389/fmicb.2022.821808] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 01/19/2022] [Indexed: 01/12/2023] Open
Abstract
Xanthomonas arboricola pv. pruni (Xap) causes bacterial spot, a major worldwide disease of Prunus species. Very few chemical management options are available for this disease and frequent applications of oxytetracycline (OTC) in the United States peach orchards have raised concerns about resistance development. During 2017-2020, 430 Xap strains were collected from ten peach orchards in South Carolina. Seven OTC-resistant (OTC R ) Xap strains were found in 2017 and 2020 from four orchards about 20-270 km apart. Interestingly, the seven strains were also resistant to streptomycin (STR). Six strains grew on media amended with ≤100 μg/mL OTC, while one strain, R1, grew on ≤250 μg/mL OTC. Genome sequence analysis of four representative OTC R strains revealed a 14-20 kb plasmid carrying tetC, tetR, and strAB in each strain. These three genes were transferable to Xanthomonas perforans via conjugation, and they were PCR confirmed in all seven OTC R Xap strains. When tetC and tetR were cloned and expressed together in a sensitive strain, the transconjugants showed resistance to ≤100 μg/mL OTC. When tetC was cloned and expressed alone in a sensitive strain, the transconjugants showed resistance to ≤250 μg/mL OTC. TetC and tetR expression was inducible by OTC in all six wild-type strains resistant to ≤100 μg/mL OTC. However, in the R1 strain resistant to ≤250 μg/mL OTC, tetR was not expressed, possibly due to the presence of Tn3 in the tetR gene, and in this case tetC was constitutively expressed. These data suggest that tetC confers OTC resistance in Xap strains, and tetR regulates the level of OTC resistance conferred by tetC. To our knowledge, this is the first report of OTC resistance in plant pathogenic xanthomonads.
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Affiliation(s)
- Austin Herbert
- Edisto Research and Education Center, Clemson University, Blackville, SC, United States
| | - C. Nathan Hancock
- Department of Biology and Geology, University of South Carolina Aiken, Aiken, SC, United States
| | - Brodie Cox
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC, United States
| | - Guido Schnabel
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC, United States
| | - Daniela Moreno
- Edisto Research and Education Center, Clemson University, Blackville, SC, United States
| | - Renato Carvalho
- Department of Plant Pathology, University of Florida, Gainesville, FL, United States
- North Florida Research and Education Center, University of Florida, Quincy, FL, United States
| | - Jeffrey Jones
- Department of Plant Pathology, University of Florida, Gainesville, FL, United States
| | - Matthew Paret
- Department of Plant Pathology, University of Florida, Gainesville, FL, United States
- North Florida Research and Education Center, University of Florida, Quincy, FL, United States
| | - Xueqing Geng
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Hehe Wang
- Edisto Research and Education Center, Clemson University, Blackville, SC, United States
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10
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Weisberg AJ, Miller M, Ream W, Grünwald NJ, Chang JH. Diversification of plasmids in a genus of pathogenic and nitrogen-fixing bacteria. Philos Trans R Soc Lond B Biol Sci 2022; 377:20200466. [PMID: 34839700 PMCID: PMC8628075 DOI: 10.1098/rstb.2020.0466] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Members of the agrobacteria-rhizobia complex (ARC) have multiple and diverse plasmids. The extent to which these plasmids are shared and the consequences of their interactions are not well understood. We extracted over 4000 plasmid sequences from 1251 genome sequences and constructed a network to reveal interactions that have shaped the evolutionary histories of oncogenic virulence plasmids. One newly discovered type of oncogenic plasmid is a mosaic with three incomplete, but complementary and partially redundant virulence loci. Some types of oncogenic plasmids recombined with accessory plasmids or acquired large regions not known to be associated with pathogenicity. We also identified two classes of partial virulence plasmids. One class is potentially capable of transforming plants, but not inciting disease symptoms. Another class is inferred to be incomplete and non-functional but can be found as coresidents of the same strain and together are predicted to confer pathogenicity. The modularity and capacity for some plasmids to be transmitted broadly allow them to diversify, convergently evolve adaptive plasmids and shape the evolution of genomes across much of the ARC. This article is part of the theme issue 'The secret lives of microbial mobile genetic elements'.
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Affiliation(s)
- Alexandra J. Weisberg
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA
| | - Marilyn Miller
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA
| | - Walt Ream
- Department of Microbiology, Oregon State University, Corvallis, OR 97331, USA
| | - Niklaus J. Grünwald
- Horticultural Crops Research Laboratory, United States Department of Agriculture and Agricultural Research Service, Corvallis, OR 97330, USA
| | - Jeff H. Chang
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA
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11
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Plasmids Bring Additional Capabilities to Caulobacter Isolates. Curr Microbiol 2022; 79:45. [PMID: 34982248 PMCID: PMC8812328 DOI: 10.1007/s00284-021-02742-z] [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: 02/10/2021] [Accepted: 12/06/2021] [Indexed: 01/07/2023]
Abstract
Caulobacter is a well-studied bacterial genus, but little is known about the plasmids that are found in some wild Caulobacter isolates. We used bioinformatic approaches to identify nine plasmids from seven different Caulobacter strains and grouped them based on their size and the similarity of their repABC, parAB, and mobAB genes. Protein pathway analysis of the genes on the K31p1 and K31p2 plasmids showed many metabolic pathways that would enhance the metabolic versatility of the host strain. In contrast, the CB4 plasmid contained 21 heavy metal resistance genes with the majority coding for proteins that enhance copper resistance. Growth assays of C. henricii CB4 demonstrated increased copper resistance and quantitative PCR showed an increase in the expression of eight heavy metal genes when induced with copper.
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12
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DNA Methylation in
Ensifer
Species during Free-Living Growth and during Nitrogen-Fixing Symbiosis with
Medicago
spp. mSystems 2022; 7:e0109221. [PMID: 35089065 PMCID: PMC8725594 DOI: 10.1128/msystems.01092-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Nitrogen fixation by rhizobia in symbiosis with legumes is economically and ecologically important. The symbiosis can involve a complex bacterial transformation—terminal differentiation—that includes major shifts in the transcriptome and cell cycle.
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Hooykaas MJG, Hooykaas PJJ. Complete genomic sequence and phylogenomics analysis of Agrobacterium strain AB2/73: a new Rhizobium species with a unique mega-Ti plasmid. BMC Microbiol 2021; 21:295. [PMID: 34711172 PMCID: PMC8554961 DOI: 10.1186/s12866-021-02358-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 10/06/2021] [Indexed: 01/18/2023] Open
Abstract
Background The Agrobacterium strain AB2/73 has a unique host range for the induction of crown gall tumors, and contains an exceptionally large, over 500 kbp mega Ti plasmid. We used whole genome sequencing to fully characterize and comparatively analyze the complex genome of strain AB2/73, including its Ti plasmid and virulence factors. Results We obtained a high-quality, full genomic sequence of AB2/73 by a combination of short-read Illumina sequencing and long-read Nanopore sequencing. The AB2/73 genome has a total size of 7,266,754 bp with 59.5% GC for which 7012 genes (6948 protein coding sequences) are predicted. Phylogenetic and comparative genomics analysis revealed that strain AB2/73 does not belong to the genus Agrobacterium, but to a new species in the genus Rhizobium, which is most related to Rhizobium tropici. In addition to the chromosome, the genome consists of 6 plasmids of which the largest two, of more than 1 Mbp, have chromid-like properties. The mega Ti plasmid is 605 kbp in size and contains two, one of which is incomplete, repABC replication units and thus appears to be a cointegrate consisting of about 175 kbp derived from an unknown Ti plasmid linked to 430 kbp from another large plasmid. In pTiAB2/73 we identified a complete set of virulence genes and two T-DNAs. Besides the previously described T-DNA we found a larger, second T-DNA containing a 6b-like onc gene and the acs gene for agrocinopine synthase. Also we identified two clusters of genes responsible for opine catabolism, including an acc-operon for agrocinopine degradation, and genes putatively involved in ridéopine catabolism. The plasmid also harbours tzs, iaaM and iaaH genes for the biosynthesis of the plant growth regulators cytokinin and auxin. Conclusions The comparative genomics analysis of the high quality genome of strain AB2/73 provided insight into the unusual phylogeny and genetic composition of the limited host range Agrobacterium strain AB2/73. The description of its unique genomic composition and of all the virulence determinants in pTiAB2/73 will be an invaluable tool for further studies into the special host range properties of this bacterium. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-021-02358-0.
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14
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Nielsen TK, Horemans B, Lood C, T'Syen J, van Noort V, Lavigne R, Ellegaard-Jensen L, Hylling O, Aamand J, Springael D, Hansen LH. The complete genome of 2,6-dichlorobenzamide (BAM) degrader Aminobacter sp. MSH1 suggests a polyploid chromosome, phylogenetic reassignment, and functions of plasmids. Sci Rep 2021; 11:18943. [PMID: 34556718 PMCID: PMC8460812 DOI: 10.1038/s41598-021-98184-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 09/03/2021] [Indexed: 11/14/2022] Open
Abstract
Aminobacter sp. MSH1 (CIP 110285) can use the pesticide dichlobenil and its recalcitrant transformation product, 2,6-dichlorobenzamide (BAM), as sole source of carbon, nitrogen, and energy. The concentration of BAM in groundwater often exceeds the threshold limit for drinking water, requiring additional treatment in drinking water treatment plants or closure of the affected abstraction wells. Biological treatment with MSH1 is considered a potential sustainable alternative to remediate BAM-contamination in drinking water production. We present the complete genome of MSH1, which was determined independently in two institutes at Aarhus University and KU Leuven. Divergences were observed between the two genomes, i.e. one of them lacked four plasmids compared to the other. Besides the circular chromosome and the two previously described plasmids involved in BAM catabolism, pBAM1 and pBAM2, the genome of MSH1 contained two megaplasmids and three smaller plasmids. The MSH1 substrain from KU Leuven showed a reduced genome lacking a megaplasmid and three smaller plasmids and was designated substrain MK1, whereas the Aarhus variant with all plasmids was designated substrain DK1. A plasmid stability experiment indicate that substrain DK1 may have a polyploid chromosome when growing in R2B medium with more chromosomes than plasmids per cell. Finally, strain MSH1 is reassigned as Aminobacter niigataensis MSH1.
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Affiliation(s)
- Tue Kjærgaard Nielsen
- Section for Microbiology and Biotechnology, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg, Copenhagen, Denmark
| | - Benjamin Horemans
- Division of Soil and Water Management, Department of Earth and Environmental Sciences, Faculty of Bioscience Engineering, KU Leuven, Kasteelpark Arenberg 20 bus 2459, 3001, Leuven, Belgium.,Sustainable Materials Unit, BAT Knowledge Centre, Vlaams Instituut voor Technologisch Onderzoek, Mol, Belgium
| | - Cédric Lood
- Department of Microbial and Molecular Systems (M2S), Faculty of Bioscience Engineering, Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium.,Laboratory of Gene Technology, Department of Biosystems, Faculty of Bioscience Engineering, KU Leuven, Leuven, Belgium
| | - Jeroen T'Syen
- Division of Soil and Water Management, Department of Earth and Environmental Sciences, Faculty of Bioscience Engineering, KU Leuven, Kasteelpark Arenberg 20 bus 2459, 3001, Leuven, Belgium
| | - Vera van Noort
- Department of Microbial and Molecular Systems (M2S), Faculty of Bioscience Engineering, Centre of Microbial and Plant Genetics, KU Leuven, Leuven, Belgium
| | - Rob Lavigne
- Laboratory of Gene Technology, Department of Biosystems, Faculty of Bioscience Engineering, KU Leuven, Leuven, Belgium
| | - Lea Ellegaard-Jensen
- Section of Environmental Microbiology and Circular Resource Flow, Department of Environmental Science, Aarhus University, Roskilde, Denmark
| | - Ole Hylling
- Section of Environmental Microbiology and Circular Resource Flow, Department of Environmental Science, Aarhus University, Roskilde, Denmark
| | - Jens Aamand
- Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Copenhagen, Denmark
| | - Dirk Springael
- Division of Soil and Water Management, Department of Earth and Environmental Sciences, Faculty of Bioscience Engineering, KU Leuven, Kasteelpark Arenberg 20 bus 2459, 3001, Leuven, Belgium.
| | - Lars Hestbjerg Hansen
- Section for Microbiology and Biotechnology, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg, Copenhagen, Denmark.
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15
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Otten L. T-DNA regions from 350 Agrobacterium genomes: maps and phylogeny. PLANT MOLECULAR BIOLOGY 2021; 106:239-258. [PMID: 33826062 DOI: 10.1007/s11103-021-01140-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Accepted: 03/12/2021] [Indexed: 05/27/2023]
Abstract
Analysis of 350 Agrobacterium wgs sequences reveals complex evolutionary history of T-DNA regions Virulent Agrobacterium strains transfer one or more plasmid DNA fragments to plant cells during a well-characterized transformation process. The transferred DNA sequences (T-DNA regions) are delimited by 25 nucleotide long conserved border sequences. Until recently, relatively few T-DNA regions were known. However, due to increased whole genome sequencing efforts, about 400 Agrobacterium sequences have now become available, 350 of which contain T-DNA regions. Detailed analysis identified 92 different T-DNA regions and several new T-DNA genes. T-DNA regions can be divided into three groups. I. Typical Agrobacterium rhizogenes T-DNA regions with rol genes. II. A large group of T-DNA regions with iaa and ipt genes, which can be further subdivided into seven subgroups. III. A small group of unusual T-DNA regions. The evolutionary relation between the T-DNA regions could not be completely elucidated, because of the lack of evolutionary intermediates. Several clusters of highly related structures suggest that evolution of T-DNA regions proceeds by slow, progressive evolution of gene sequences, accompanied by rapid changes in overall structure, due to recombination between T-DNA regions of different origins, and insertion of bacterial insertion sequences (IS). Divergence values for T-DNA genes suggest that they were recruited at different times in evolution. An attempt was made to link T-DNA region evolution to plasmid evolution. The present study provides a solid basis for further studies on T-DNA region diversity and evolution.
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Affiliation(s)
- Léon Otten
- Institut de Biologie Moléculaire des Plantes, 12 Rue du Général Zimmer, 67084, Strasbourg, France.
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16
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Barton IS, Eagan JL, Nieves-Otero PA, Reynolds IP, Platt TG, Fuqua C. Co-dependent and Interdigitated: Dual Quorum Sensing Systems Regulate Conjugative Transfer of the Ti Plasmid and the At Megaplasmid in Agrobacterium tumefaciens 15955. Front Microbiol 2021; 11:605896. [PMID: 33552018 PMCID: PMC7856919 DOI: 10.3389/fmicb.2020.605896] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Accepted: 12/21/2020] [Indexed: 11/13/2022] Open
Abstract
Members of the Rhizobiaceae, often carry multiple secondary replicons in addition to the primary chromosome with compatible repABC-based replication systems. Unlike secondary chromosomes and chromids, repABC-based megaplasmids and plasmids can undergo copy number fluctuations and are capable of conjugative transfer in response to environmental signals. Several Agrobacterium tumefaciens lineages harbor three secondary repABC-based replicons, including a secondary chromosome (often linear), the Ti (tumor-inducing) plasmid and the At megaplasmid. The Ti plasmid is required for virulence and encodes a conjugative transfer (tra) system that is strictly regulated by a subset of plant-tumor released opines and a well-described acyl-homoserine lactone (AHL)-based quorum-sensing mechanism. The At plasmids are generally not required for virulence, but carry genes that enhance rhizosphere survival, and these plasmids are often conjugatively proficient. We report that the At megaplasmid of the octopine-type strain A. tumefaciens 15955 encodes a quorum-controlled conjugation system that directly interacts with the paralogous quorum sensing system on the co-resident Ti plasmid. Both the pAt15955 and pTi15955 plasmids carry homologs of a TraI-type AHL synthase, a TraR-type AHL-responsive transcription activator, and a TraM-type anti-activator. The traI genes from both pTi15955 and pAt15955 can direct production of the inducing AHL (3-octanoyl-L-homoserine lactone) and together contribute to the overall AHL pool. The TraR protein encoded on each plasmid activates AHL-responsive transcription of target tra gene promoters. The pAt15955 TraR can cross-activate tra genes on the Ti plasmid as strongly as its cognate tra genes, whereas the pTi15955 TraR is preferentially biased toward its own tra genes. Putative tra box elements are located upstream of target promoters, and comparing between plasmids, they are in similar locations and share an inverted repeat structure, but have distinct consensus sequences. The two AHL quorum sensing systems have a combinatorial effect on conjugative transfer of both plasmids. Overall, the interactions described here have implications for the horizontal transfer and evolutionary stability of both plasmids and, in a broad sense, are consistent with other repABC systems that often have multiple quorum-sensing controlled secondary replicons.
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Affiliation(s)
- Ian S Barton
- Department of Biology, Indiana University, Bloomington, IN, United States
| | - Justin L Eagan
- Department of Biology, Indiana University, Bloomington, IN, United States
| | | | - Ian P Reynolds
- Department of Biology, Indiana University, Bloomington, IN, United States
| | - Thomas G Platt
- Division of Biology, Kansas State University, Manhattan, KS, United States
| | - Clay Fuqua
- Department of Biology, Indiana University, Bloomington, IN, United States
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17
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Segregation of four Agrobacterium tumefaciens replicons during polar growth: PopZ and PodJ control segregation of essential replicons. Proc Natl Acad Sci U S A 2020; 117:26366-26373. [PMID: 33024016 DOI: 10.1073/pnas.2014371117] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Agrobacterium tumefaciens C58 contains four replicons, circular chromosome (CC), linear chromosome (LC), cryptic plasmid (pAt), and tumor-inducing plasmid (pTi), and grows by polar growth from a single growth pole (GP), while the old cell compartment and its old pole (OP) do not elongate. We monitored the replication and segregation of these four genetic elements during polar growth. The three largest replicons (CC, LC, pAt) reside in the OP compartment prior to replication; post replication one copy migrates to the GP prior to division. CC resides at a fixed location at the OP and replicates first. LC does not stay fixed at the OP once the cell cycle begins and replicates from varied locations 20 min later than CC. pAt localizes similarly to LC prior to replication, but replicates before the LC and after the CC. pTi does not have a fixed location, and post replication it segregates randomly throughout old and new cell compartments, while undergoing one to three rounds of replication during a single cell cycle. Segregation of the CC and LC is dependent on the GP and OP identity factors PopZ and PodJ, respectively. Without PopZ, replicated CC and LC do not efficiently partition, resulting in sibling cells without CC or LC. Without PodJ, the CC and LC exhibit abnormal localization to the GP at the beginning of the cell cycle and replicate from this position. These data reveal PodJ plays an essential role in CC and LC tethering to the OP during early stages of polar growth.
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18
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Abstract
Plasmids are ubiquitous in the microbial world and have been identified in almost all species of bacteria that have been examined. Their localization inside the bacterial cell has been examined for about two decades; typically, they are not randomly distributed, and their positioning depends on copy number and their mode of segregation. Low-copy-number plasmids promote their own stable inheritance in their bacterial hosts by encoding active partition systems, which ensure that copies are positioned in both halves of a dividing cell. High-copy plasmids rely on passive diffusion of some copies, but many remain clustered together in the nucleoid-free regions of the cell. Here we review plasmid localization and partition (Par) systems, with particular emphasis on plasmids from Enterobacteriaceae and on recent results describing the in vivo localization properties and molecular mechanisms of each system. Partition systems also cause plasmid incompatibility such that distinct plasmids (with different replicons) with the same Par system cannot be stably maintained in the same cells. We discuss how partition-mediated incompatibility is a consequence of the partition mechanism.
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19
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Complete Genome Sequence of Sinorhizobium meliloti Strain AK21, a Salt-Tolerant Isolate from the Aral Sea Region. Microbiol Resour Announc 2020; 9:9/2/e01432-19. [PMID: 31919182 PMCID: PMC6952668 DOI: 10.1128/mra.01432-19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
We report here the complete genome sequence of the salt-tolerant Sinorhizobium meliloti strain AK21, isolated from nodules of Medicago sativa L. subsp. ambigua inhabiting the northern Aral Sea Region. This genome (7.36 Mb) consists of a chromosome and four accessory plasmids, two of which are the symbiotic megaplasmids pSymA and pSymB. We report here the complete genome sequence of the salt-tolerant Sinorhizobium meliloti strain AK21, isolated from nodules of Medicago sativa L. subsp. ambigua inhabiting the northern Aral Sea Region. This genome (7.36 Mb) consists of a chromosome and four accessory plasmids, two of which are the symbiotic megaplasmids pSymA and pSymB.
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20
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Carrillo M, Wagner M, Petit F, Dransfeld A, Becker A, Erb TJ. Design and Control of Extrachromosomal Elements in Methylorubrum extorquens AM1. ACS Synth Biol 2019; 8:2451-2456. [PMID: 31584803 PMCID: PMC6862569 DOI: 10.1021/acssynbio.9b00220] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
![]()
Genetic
tools are a prerequisite to engineer cellular factories
for synthetic biology and biotechnology. Methylorubrum extorquens AM1 is an important platform organism of a future C1-bioeconomy.
However, its application is currently limited by the availability
of genetic tools. Here we systematically tested repABC regions to maintain extrachromosomal DNA in M. extorquens. We used three elements to construct mini-chromosomes that are stably
inherited at single copy number and can be shuttled between Escherichia coli and M. extorquens. These mini-chromosomes are compatible among each other and with
high-copy number plasmids of M. extorquens.
We also developed a set of inducible promoters of wide expression
range, reaching levels exceeding those currently available, notably
the PmxaF-promoter. In
summary, we provide a set of tools to control the dynamic expression
and copy number of genetic elements in M. extorquens, which opens new ways to unleash the metabolic and biotechnological
potential of this organism for future applications.
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Affiliation(s)
- Martina Carrillo
- Department of Biochemistry & Synthetic Metabolism, Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Str. 10, 35043 Marburg, Germany
| | - Marcel Wagner
- LOEWE Center for Synthetic Microbiology, 35043 Marburg, Germany
| | - Florian Petit
- Department of Biochemistry & Synthetic Metabolism, Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Str. 10, 35043 Marburg, Germany
| | - Amelie Dransfeld
- Department of Biochemistry & Synthetic Metabolism, Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Str. 10, 35043 Marburg, Germany
- LOEWE Center for Synthetic Microbiology, 35043 Marburg, Germany
| | - Anke Becker
- LOEWE Center for Synthetic Microbiology, 35043 Marburg, Germany
| | - Tobias J. Erb
- Department of Biochemistry & Synthetic Metabolism, Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Str. 10, 35043 Marburg, Germany
- LOEWE Center for Synthetic Microbiology, 35043 Marburg, Germany
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21
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Li X, Wang H, Tong W, Feng L, Wang L, Rahman SU, Wei G, Tao S. Exploring the evolutionary dynamics of Rhizobium plasmids through bipartite network analysis. Environ Microbiol 2019; 22:934-951. [PMID: 31361937 DOI: 10.1111/1462-2920.14762] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 06/24/2019] [Accepted: 07/25/2019] [Indexed: 10/26/2022]
Abstract
The genus Rhizobium usually has a multipartite genome architecture with a chromosome and several plasmids, making these bacteria a perfect candidate for plasmid biology studies. As there are no universally shared genes among typical plasmids, network analyses can complement traditional phylogenetics in a broad-scale study of plasmid evolution. Here, we present an exhaustive analysis of 216 plasmids from 49 complete genomes of Rhizobium by constructing a bipartite network that consists of two classes of nodes, the plasmids and homologous protein families that connect them. Dissection of the network using a hierarchical clustering strategy reveals extensive variety, with 34 homologous plasmid clusters. Four large clusters including one cluster of symbiotic plasmids and two clusters of chromids carrying some truly essential genes are widely distributed among Rhizobium. In contrast, the other clusters are quite small and rare. Symbiotic clusters and rare accessory clusters are exogenetic and do not appear to have co-evolved with the common accessory clusters; the latter ones have a large coding potential and functional complementarity for different lifestyles in Rhizobium. The bipartite network also provides preliminary evidence of Rhizobium plasmid variation and formation including genetic exchange, plasmid fusion and fission, exogenetic plasmid transfer, host plant selection, and environmental adaptation.
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Affiliation(s)
- Xiangchen Li
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China.,Bioinformatics Center, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Hao Wang
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China.,Bioinformatics Center, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Wenjun Tong
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Li Feng
- College of Enology, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Lina Wang
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China.,Bioinformatics Center, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Siddiq Ur Rahman
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China.,Bioinformatics Center, Northwest A&F University, Yangling, Shaanxi, 712100, China.,Department of Computer Science and Bioinformatics, Khushal Khan Khattak University, Karak, Khyber Pakhtunkhwa, 27200, Pakistan
| | - Gehong Wei
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Shiheng Tao
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China.,Bioinformatics Center, Northwest A&F University, Yangling, Shaanxi, 712100, China
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22
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Molecular Mechanism of N, N-Dimethylformamide Degradation in Methylobacterium sp. Strain DM1. Appl Environ Microbiol 2019; 85:AEM.00275-19. [PMID: 30952664 DOI: 10.1128/aem.00275-19] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 03/26/2019] [Indexed: 12/11/2022] Open
Abstract
N,N-Dimethylformamide (DMF) is one of the most common xenobiotic chemicals, and it can be easily emitted into the environment, where it causes harm to human beings. Herein, an efficient DMF-degrading strain, DM1, was isolated and identified as Methylobacterium sp. This strain can use DMF as the sole source of carbon and nitrogen. Whole-genome sequencing of strain DM1 revealed that it has a 5.66-Mbp chromosome and a 200-kbp megaplasmid. The plasmid pLVM1 specifically harbors the genes essential for the initial steps of DMF degradation, and the chromosome carries the genes facilitating subsequent methylotrophic metabolism. Through analysis of the transcriptome sequencing data, the complete mineralization pathway and redundant gene clusters of DMF degradation were elucidated. The dimethylformamidase (DMFase) gene was heterologously expressed, and DMFase was purified and characterized. Plasmid pLVM1 is catabolically crucial for DMF utilization, as evidenced by the phenotype identification of the plasmid-free strain. This study systematically elucidates the molecular mechanisms of DMF degradation by Methylobacterium IMPORTANCE DMF is a hazardous pollutant that has been used in the chemical industry, pharmaceutical manufacturing, and agriculture. Biodegradation as a method for removing DMF has received increasing attention. Here, we identified an efficient DMF degrader, Methylobacterium sp. strain DM1, and characterized the complete DMF mineralization pathway and enzymatic properties of DMFase in this strain. This study provides insights into the molecular mechanisms and evolutionary advantage of DMF degradation facilitated by plasmid pLVM1 and redundant genes in strain DM1, suggesting the emergence of new ecotypes of Methylobacterium.
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23
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González V, Santamaría RI, Bustos P, Pérez-Carrascal OM, Vinuesa P, Juárez S, Martínez-Flores I, Cevallos MÁ, Brom S, Martínez-Romero E, Romero D. Phylogenomic Rhizobium Species Are Structured by a Continuum of Diversity and Genomic Clusters. Front Microbiol 2019; 10:910. [PMID: 31114559 PMCID: PMC6503217 DOI: 10.3389/fmicb.2019.00910] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 04/10/2019] [Indexed: 01/07/2023] Open
Abstract
The bacterial genus Rhizobium comprises diverse symbiotic nitrogen-fixing species associated with the roots of plants in the Leguminosae family. Multiple genomic clusters defined by whole genome comparisons occur within Rhizobium, but their equivalence to species is controversial. In this study we investigated such genomic clusters to ascertain their significance in a species phylogeny context. Phylogenomic inferences based on complete sets of ribosomal proteins and stringent core genome markers revealed the main lineages of Rhizobium. The clades corresponding to R. etli and R. leguminosarum species show several genomic clusters with average genomic nucleotide identities (ANI > 95%), and a continuum of divergent strains, respectively. They were found to be inversely correlated with the genetic distance estimated from concatenated ribosomal proteins. We uncovered evidence of a Rhizobium pangenome that was greatly expanded, both in its chromosomes and plasmids. Despite the variability of extra-chromosomal elements, our genomic comparisons revealed only a few chromid and plasmid families. The presence/absence profile of genes in the complete Rhizobium genomes agreed with the phylogenomic pattern of species divergence. Symbiotic genes were distributed according to the principal phylogenomic Rhizobium clades but did not resolve genome clusters within the clades. We distinguished some types of symbiotic plasmids within Rhizobium that displayed different rates of synonymous nucleotide substitutions in comparison to chromosomal genes. Symbiotic plasmids may have been repeatedly transferred horizontally between strains and species, in the process displacing and substituting pre-existing symbiotic plasmids. In summary, the results indicate that Rhizobium genomic clusters, as defined by whole genomic identities, might be part of a continuous process of evolutionary divergence that includes the core and the extrachromosomal elements leading to species formation.
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Affiliation(s)
- Víctor González
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Rosa Isela Santamaría
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Patricia Bustos
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | | | - Pablo Vinuesa
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Soledad Juárez
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Irma Martínez-Flores
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Miguel Ángel Cevallos
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Susana Brom
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | | | - David Romero
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
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24
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In Vivo Imaging of the Segregation of the 2 Chromosomes and the Cell Division Proteins of Rhodobacter sphaeroides Reveals an Unexpected Role for MipZ. mBio 2019; 10:mBio.02515-18. [PMID: 30602584 PMCID: PMC6315104 DOI: 10.1128/mbio.02515-18] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Cell division has to be coordinated with chromosome segregation to ensure the stable inheritance of genetic information. We investigated this coordination in the multichromosome bacterium Rhodobacter sphaeroides. By examining the origin and terminus regions of the two chromosomes, the ParA-like ATPase MipZ and FtsZ, we showed that chromosome 1 appears to be the “master” chromosome connecting DNA segregation and cell division, with MipZ being critical for coordination. MipZ shows an unexpected localization pattern, with MipZ monomers interacting with ParB of the chromosome 1 at the cell poles whereas MipZ dimers colocalize with FtsZ at midcell during constriction, both forming dynamic rings. These data suggest that MipZ has roles in R. sphaeroides in both controlling septation and coordinating chromosome segregation with cell division. Coordinating chromosome duplication and segregation with cell division is clearly critical for bacterial species with one chromosome. The precise choreography required is even more complex in species with more than one chromosome. The alpha subgroup of bacteria contains not only one of the best-studied bacterial species, Caulobacter crescentus, but also several species with more than one chromosome. Rhodobacter sphaeroides is an alphaproteobacterium with two chromosomes, but, unlike C. crescentus, it divides symmetrically rather than buds and lacks the complex CtrA-dependent control mechanism. By examining the Ori and Ter regions of both chromosomes and associated ParA and ParB proteins relative to cell division proteins FtsZ and MipZ, we have identified a different pattern of chromosome segregation and cell division. The pattern of chromosome duplication and segregation resembles that of Vibrio cholerae, not that of Agrobacterium tumefaciens, with duplication of the origin and terminus regions of chromosome 2 controlled by chromosome 1. Key proteins are localized to different sites compared to C. crescentus. OriC1 and ParB1 are localized to the old pole, while MipZ and FtsZ localize to the new pole. Movement of ParB1 to the new pole following chromosome duplication releases FtsZ, which forms a ring at midcell, but, unlike reports for other species, MipZ monomers do not form a gradient but oscillate between poles, with the nucleotide-bound monomer and the dimer localizing to midcell. MipZ dimers form a single ring (with a smaller diameter) close to the FtsZ ring at midcell and constrict with the FtsZ ring. Overproduction of the dimer form results in filamentation, suggesting that MipZ dimers are regulating FtsZ activity and thus septation. This is an unexpected role for MipZ and provides a new model for the integration of chromosome segregation and cell division.
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Wetzel ME, Asenstorfer RE, Tate ME, Farrand SK. Quorum-dependent transfer of the opine-catabolic plasmid pAoF64/95 is regulated by a novel mechanism involving inhibition of the TraR antiactivator TraM. Microbiologyopen 2019; 8:e00625. [PMID: 29635848 PMCID: PMC6341043 DOI: 10.1002/mbo3.625] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 01/27/2018] [Accepted: 01/30/2018] [Indexed: 11/06/2022] Open
Abstract
We previously described a plasmid of Agrobacterium spp., pAoF64/95, in which the quorum-sensing system that controls conjugative transfer is induced by the opine mannopine. We also showed that the quorum-sensing regulators TraR, TraM, and TraI function similarly to their counterparts in other repABC plasmids. However, traR, unlike its counterpart on Ti plasmids, is monocistronic and not located in an operon that is inducible by the conjugative opine. Here, we report that both traR and traM are expressed constitutively and not regulated by growth with mannopine. We report two additional regulatory genes, mrtR and tmsP, that are involved in a novel mechanism of control of TraR activity. Both genes are located in the distantly linked region of pAoF64/95 encoding mannopine utilization. MrtR, in the absence of mannopine, represses the four-gene mocC operon as well as tmsP, which is the distal gene of the eight-gene motA operon. As judged by a bacterial two-hybrid analysis, TmsP, which shows amino acid sequence relatedness with the TraM-binding domain of TraR, interacts with the antiactivator. We propose a model in which mannopine, acting through the repressor MrtR, induces expression of TmsP which then titrates the levels of TraM thereby freeing TraR to activate the tra regulon.
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Affiliation(s)
- Margaret E. Wetzel
- Department of MicrobiologyThe University of Illinois at Urbana‐ChampaignUrbanaILUSA
| | | | - Max E. Tate
- School of Agriculture, Food and WineThe University of AdelaideOsmondSAAustralia
| | - Stephen K. Farrand
- Department of MicrobiologyThe University of Illinois at Urbana‐ChampaignUrbanaILUSA
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26
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Yano H, Shintani M, Tomita M, Suzuki H, Oshima T. Reconsidering plasmid maintenance factors for computational plasmid design. Comput Struct Biotechnol J 2018; 17:70-81. [PMID: 30619542 PMCID: PMC6312765 DOI: 10.1016/j.csbj.2018.12.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Revised: 12/08/2018] [Accepted: 12/09/2018] [Indexed: 12/18/2022] Open
Abstract
Plasmids are genetic parasites of microorganisms. The genomes of naturally occurring plasmids are expected to be polished via natural selection to achieve long-term persistence in the microbial cell population. However, plasmid genomes are extremely diverse, and the rules governing plasmid genomes are not fully understood. Therefore, computationally designing plasmid genomes optimized for model and nonmodel organisms remains challenging. Here, we summarize current knowledge of the plasmid genome organization and the factors that can affect plasmid persistence, with the aim of constructing synthetic plasmids for use in gram-negative bacteria. Then, we introduce publicly available resources, plasmid data, and bioinformatics tools that are useful for computational plasmid design.
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Affiliation(s)
- Hirokazu Yano
- Graduate School of Life Sciences, Tohoku University, 2-1-1, Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Masaki Shintani
- Department of Engineering, Graduate School of Integrated Science and Technology, Shizuoka University, 3-5-1, Hamamatsu 432-8561, Japan
- Department of Bioscience, Graduate School of Science and Technology, Shizuoka University, 3-5-1, Hamamatsu 432-8561, Japan
| | - Masaru Tomita
- Institute for Advanced Biosciences, Keio University, 14-1, Baba-cho, Tsuruoka, Yamagata 997-0035, Japan
- Faculty of Environment and Information Studies, Keio University, 5322, Endo, Fujisawa, Kanagawa 252-0882, Japan
| | - Haruo Suzuki
- Institute for Advanced Biosciences, Keio University, 14-1, Baba-cho, Tsuruoka, Yamagata 997-0035, Japan
- Faculty of Environment and Information Studies, Keio University, 5322, Endo, Fujisawa, Kanagawa 252-0882, Japan
| | - Taku Oshima
- Department of Biotechnology, Toyama Prefectural University, 5180, Kurokawa, Imizu, Toyama 939-0398, Japan
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27
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Vaghchhipawala Z, Radke S, Nagy E, Russell ML, Johnson S, Gelvin SB, Gilbertson LA, Ye X. RepB C-terminus mutation of a pRi-repABC binary vector affects plasmid copy number in Agrobacterium and transgene copy number in plants. PLoS One 2018; 13:e0200972. [PMID: 30412579 PMCID: PMC6226153 DOI: 10.1371/journal.pone.0200972] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 10/26/2018] [Indexed: 12/23/2022] Open
Abstract
A native repABC replication origin from pRiA4b was previously reported as a single copy plasmid in Agrobacterium tumefaciens and can improve the production of transgenic plants with a single copy insertion of transgenes when it is used in binary vectors for Agrobacterium-mediated transformation. A high copy pRi-repABC variant plasmid, pTF::Ri, which does not improve the frequency of single copy transgenic plants, has been reported in the literature. Sequencing the high copy pTF::Ri repABC operon revealed the presence of two mutations: one silent mutation and one missense mutation that changes a tyrosine to a histidine (Y299H) in a highly conserved area of the C-terminus of the RepB protein (RepBY299H). Reproducing these mutations in the wild-type pRi-repABC binary vector showed that Agrobacterium cells with the RepBY299H mutation grow faster on both solidified and in liquid medium, and have higher plasmid copy number as determined by ddPCR. In order to investigate the impact of the RepBY299H mutation on transformation and quality plant production, the RepBY299H mutated pRi-repABC binary vector was compared with the original wild-type pRi-repABC binary vector and a multi-copy oriV binary vector in canola transformation. Molecular analyses of the canola transgenic plants demonstrated that the multi-copy pRi-repABC with the RepBY299H mutation provides no advantage in generating high frequency single copy, backbone-free transgenic plants in comparison with the single copy wild-type pRi-repABC binary vector.
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Affiliation(s)
| | - Sharon Radke
- Woodland Campus, Monsanto Company, Woodland, CA, United States of America
| | - Ervin Nagy
- Monsanto Company, St. Louis, MO, United States of America
| | - Mary L. Russell
- Woodland Campus, Monsanto Company, Woodland, CA, United States of America
| | - Susan Johnson
- Monsanto Company, St. Louis, MO, United States of America
- Department of Biological Sciences, Purdue University, West Lafayette, IN, United States of America
| | - Stanton B. Gelvin
- Department of Biological Sciences, Purdue University, West Lafayette, IN, United States of America
| | | | - Xudong Ye
- Monsanto Company, St. Louis, MO, United States of America
- * E-mail:
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28
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Lasek R, Szuplewska M, Mitura M, Decewicz P, Chmielowska C, Pawłot A, Sentkowska D, Czarnecki J, Bartosik D. Genome Structure of the Opportunistic Pathogen Paracoccus yeei ( Alphaproteobacteria) and Identification of Putative Virulence Factors. Front Microbiol 2018; 9:2553. [PMID: 30410477 PMCID: PMC6209633 DOI: 10.3389/fmicb.2018.02553] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 10/05/2018] [Indexed: 12/17/2022] Open
Abstract
Bacteria of the genus Paracoccus are common components of the microbiomes of many naturally- and anthropogenically shaped environments. One species, Paracoccus yeei, is unique within the genus because it is associated with opportunistic human infections. Therefore, strains of P. yeei may serve as an interesting model to study the transition from a saprophytic to a pathogenic lifestyle in environmental bacteria. Unfortunately, knowledge concerning the biology, genetics and genomic content of P. yeei is fragmentary; also the mechanisms of pathogenicity of this bacterium remain unclear. In this study we provide the first insight into the genome composition and metabolic potential of a clinical isolate, P. yeei CCUG 32053. This strain has a multipartite genome (4,632,079 bp) composed of a circular chromosome plus eight extrachromosomal replicons pYEE1–8: 3 chromids and 5 plasmids, with a total size of 1,247,173 bp. The genome has been significantly shaped by the acquisition of genomic islands, prophages (Myoviridae and Siphoviridae phage families) and numerous insertion sequences (ISs) representing seven IS families. Detailed comparative analysis with other complete genomic sequences of Paracoccus spp. (including P. yeei FDAARGOS_252 and TT13, as well as non-pathogenic strains of other species in this genus) enabled us to identify P. yeei species-specific genes and to predict putative determinants of virulence. This is the first attempt to identify pathoadaptive genetic information of P. yeei and to estimate the role of the mobilome in the evolution of pathogenicity in this species.
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Affiliation(s)
- Robert Lasek
- Department of Bacterial Genetics, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Magdalena Szuplewska
- Department of Bacterial Genetics, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Monika Mitura
- Department of Bacterial Genetics, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Przemysław Decewicz
- Department of Bacterial Genetics, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Cora Chmielowska
- Department of Bacterial Genetics, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Aleksandra Pawłot
- Department of Bacterial Genetics, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Dorota Sentkowska
- Department of Bacterial Genetics, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Jakub Czarnecki
- Department of Bacterial Genetics, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Dariusz Bartosik
- Department of Bacterial Genetics, Faculty of Biology, University of Warsaw, Warsaw, Poland
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29
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Fournes F, Val ME, Skovgaard O, Mazel D. Replicate Once Per Cell Cycle: Replication Control of Secondary Chromosomes. Front Microbiol 2018; 9:1833. [PMID: 30131796 PMCID: PMC6090056 DOI: 10.3389/fmicb.2018.01833] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 07/23/2018] [Indexed: 12/13/2022] Open
Abstract
Faithful vertical transmission of genetic information, especially of essential core genes, is a prerequisite for bacterial survival. Hence, replication of all the replicons is tightly controlled to ensure that all daughter cells get the same genome copy as their mother cell. Essential core genes are very often carried by the main chromosome. However they can occasionally be found on secondary chromosomes, recently renamed chromids. Chromids have evolved from non-essential megaplasmids, and further acquired essential core genes and a genomic signature closed to that of the main chromosome. All chromids carry a plasmidic replication origin, belonging so far to either the iterons or repABC type. Based on these differences, two categories of chromids have been distinguished. In this review, we focus on the replication initiation controls of these two types of chromids. We show that the sophisticated mechanisms controlling their replication evolved from their plasmid counterparts to allow a timely controlled replication, occurring once per cell cycle.
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Affiliation(s)
- Florian Fournes
- Unité Plasticité du Génome Bactérien, Département Génomes et Génétique, Institut Pasteur, Paris, France.,UMR3525, Centre National de la Recherche Scientifique, Paris, France
| | - Marie-Eve Val
- Unité Plasticité du Génome Bactérien, Département Génomes et Génétique, Institut Pasteur, Paris, France.,UMR3525, Centre National de la Recherche Scientifique, Paris, France
| | - Ole Skovgaard
- Department of Science and Environment, Roskilde University, Roskilde, Denmark
| | - Didier Mazel
- Unité Plasticité du Génome Bactérien, Département Génomes et Génétique, Institut Pasteur, Paris, France.,UMR3525, Centre National de la Recherche Scientifique, Paris, France
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30
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Genome-Guided Characterization of Ochrobactrum sp. POC9 Enhancing Sewage Sludge Utilization-Biotechnological Potential and Biosafety Considerations. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2018; 15:ijerph15071501. [PMID: 30013002 PMCID: PMC6069005 DOI: 10.3390/ijerph15071501] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 07/07/2018] [Accepted: 07/12/2018] [Indexed: 11/17/2022]
Abstract
Sewage sludge is an abundant source of microorganisms that are metabolically active against numerous contaminants, and thus possibly useful in environmental biotechnologies. However, amongst the sewage sludge isolates, pathogenic bacteria can potentially be found, and such isolates should therefore be carefully tested before their application. A novel bacterial strain, Ochrobactrum sp. POC9, was isolated from a sewage sludge sample collected from a wastewater treatment plant. The strain exhibited lipolytic, proteolytic, cellulolytic, and amylolytic activities, which supports its application in biodegradation of complex organic compounds. We demonstrated that bioaugmentation with this strain substantially improved the overall biogas production and methane content during anaerobic digestion of sewage sludge. The POC9 genome content analysis provided a deeper insight into the biotechnological potential of this bacterium and revealed that it is a metalotolerant and a biofilm-producing strain capable of utilizing various toxic compounds. The strain is resistant to rifampicin, chloramphenicol and β-lactams. The corresponding antibiotic resistance genes (including blaOCH and cmlA/floR) were identified in the POC9 genome. Nevertheless, as only few genes in the POC9 genome might be linked to pathogenicity, and none of those genes is a critical virulence factor found in severe pathogens, the strain appears safe for application in environmental biotechnologies.
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31
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Catabolism of the groundwater micropollutant 2,6-dichlorobenzamide beyond 2,6-dichlorobenzoate is plasmid encoded in Aminobacter sp. MSH1. Appl Microbiol Biotechnol 2018; 102:7963-7979. [PMID: 29984394 DOI: 10.1007/s00253-018-9189-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 06/19/2018] [Accepted: 06/20/2018] [Indexed: 01/01/2023]
Abstract
Aminobacter sp. MSH1 uses the groundwater micropollutant 2,6-dichlorobenzamide (BAM) as sole source of carbon and energy. In the first step, MSH1 converts BAM to 2,6-dichlorobenzoic acid (2,6-DCBA) by means of the BbdA amidase encoded on the IncP-1β plasmid pBAM1. Information about the genes and degradation steps involved in 2,6-DCBA metabolism in MSH1 or any other organism is currently lacking. Here, we show that the genes for 2,6-DCBA degradation in strain MSH1 reside on a second catabolic plasmid in MSH1, designated as pBAM2. The complete sequence of pBAM2 was determined revealing that it is a 53.9 kb repABC family plasmid. The 2,6-DCBA catabolic genes on pBAM2 are organized in two main clusters bordered by IS elements and integrase genes and encode putative functions like Rieske mono-/dioxygenase, meta-cleavage dioxygenase, and reductive dehalogenases. The putative mono-oxygenase encoded by the bbdD gene was shown to convert 2,6-DCBA to 3-hydroxy-2,6-dichlorobenzoate (3-OH-2,6-DCBA). 3-OH-DCBA was degraded by wild-type MSH1 and not by a pBAM2-free MSH1 variant indicating that it is a likely intermediate in the pBAM2-encoded DCBA catabolic pathway. Based on the activity of BbdD and the putative functions of the other catabolic genes on pBAM2, a metabolic pathway for BAM/2,6-DCBA in strain MSH1 was suggested.
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32
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Soenens A, Imperial J. Novel, non-symbiotic isolates of Neorhizobium from a dryland agricultural soil. PeerJ 2018; 6:e4776. [PMID: 29785349 PMCID: PMC5960266 DOI: 10.7717/peerj.4776] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 04/25/2018] [Indexed: 12/21/2022] Open
Abstract
Semi-selective enrichment, followed by PCR screening, resulted in the successful direct isolation of fast-growing Rhizobia from a dryland agricultural soil. Over 50% of these isolates belong to the genus Neorhizobium, as concluded from partial rpoB and near-complete 16S rDNA sequence analysis. Further genotypic and genomic analysis of five representative isolates confirmed that they form a coherent group within Neorhizobium, closer to N. galegae than to the remaining Neorhizobium species, but clearly differentiated from the former, and constituting at least one new genomospecies within Neorhizobium. All the isolates lacked nod and nif symbiotic genes but contained a repABC replication/maintenance region, characteristic of rhizobial plasmids, within large contigs from their draft genome sequences. These repABC sequences were related, but not identical, to repABC sequences found in symbiotic plasmids from N. galegae, suggesting that the non-symbiotic isolates have the potential to harbor symbiotic plasmids. This is the first report of non-symbiotic members of Neorhizobium from soil.
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Affiliation(s)
- Amalia Soenens
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Pozuelo de Alarcón, Madrid, Spain
| | - Juan Imperial
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Pozuelo de Alarcón, Madrid, Spain.,Instituto de Ciencias Agrarias, Consejo Superior de Investigaciones Científicas, Madrid, Spain
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33
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Li X, Tong W, Wang L, Rahman SU, Wei G, Tao S. A Novel Strategy for Detecting Recent Horizontal Gene Transfer and Its Application to Rhizobium Strains. Front Microbiol 2018; 9:973. [PMID: 29867876 PMCID: PMC5968381 DOI: 10.3389/fmicb.2018.00973] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 04/25/2018] [Indexed: 11/13/2022] Open
Abstract
Recent horizontal gene transfer (HGT) is crucial for enabling microbes to rapidly adapt to their novel environments without relying upon rare beneficial mutations that arise spontaneously. For several years now, computational approaches have been developed to detect HGT, but they typically lack the sensitivity and ability to detect recent HGT events. Here we introduce a novel strategy, named RecentHGT. The number of genes undergoing recent HGT between two bacterial genomes was estimated by a new algorithm derived from the expectation-maximization algorithm and is based on the theoretical sequence-similarity distribution of orthologous genes. We tested the proposed strategy by applying it to a set of 10 Rhizobium genomes, and detected several large-scale recent HGT events. We also found that our strategy was more sensitive than other available HGT detection methods. These HGT events were mainly mediated by symbiotic plasmids. Our new strategy can provide clear evidence of recent HGT events and thus it brings us closer to the goal of detecting these potentially adaptive evolution processes in rhizobia as well as pathogens.
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Affiliation(s)
- Xiangchen Li
- College of Life Sciences and State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, China.,Bioinformatics Center, Northwest A&F University, Yangling, China
| | - Wenjun Tong
- College of Life Sciences and State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, China
| | - Lina Wang
- College of Life Sciences and State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, China.,Bioinformatics Center, Northwest A&F University, Yangling, China
| | - Siddiq Ur Rahman
- College of Life Sciences and State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, China.,Bioinformatics Center, Northwest A&F University, Yangling, China
| | - Gehong Wei
- College of Life Sciences and State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, China
| | - Shiheng Tao
- College of Life Sciences and State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, China.,Bioinformatics Center, Northwest A&F University, Yangling, China
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Nelson M, Guhlin J, Epstein B, Tiffin P, Sadowsky MJ. The complete replicons of 16 Ensifer meliloti strains offer insights into intra- and inter-replicon gene transfer, transposon-associated loci, and repeat elements. Microb Genom 2018; 4. [PMID: 29671722 PMCID: PMC5994717 DOI: 10.1099/mgen.0.000174] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Ensifer meliloti (formerly Rhizobium meliloti and Sinorhizobium meliloti) is a model bacterium for understanding legume–rhizobial symbioses. The tripartite genome of E. meliloti consists of a chromosome, pSymA and pSymB, and in some instances strain-specific accessory plasmids. The majority of previous sequencing studies have relied on the use of assemblies generated from short read sequencing, which leads to gaps and assembly errors. Here we used PacBio-based, long-read assemblies and were able to assemble, de novo, complete circular replicons. In this study, we sequenced, de novo-assembled and analysed 10 E. meliloti strains. Sequence comparisons were also done with data from six previously published genomes. We identified genome differences between the replicons, including mol% G+C and gene content, nucleotide repeats, and transposon-associated loci. Additionally, genomic rearrangements both within and between replicons were identified, providing insight into evolutionary processes at the structural level. There were few cases of inter-replicon gene transfer of core genes between the main replicons. Accessory plasmids were more similar to pSymA than to either pSymB or the chromosome, with respect to gene content, transposon content and G+C content. In our population, the accessory plasmids appeared to share an open genome with pSymA, which contains many nodulation- and nitrogen fixation-related genes. This may explain previous observations that horizontal gene transfer has a greater effect on the content of pSymA than pSymB, or the chromosome, and why some rhizobia show unstable nodulation phenotypes on legume hosts.
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Affiliation(s)
- Matthew Nelson
- 1Biotechnology Institute and Department of Soil, Water, and Climate, University of Minnesota, St. Paul, MN 55108, USA
| | - Joseph Guhlin
- 2Department of Plant and Microbial Biology, University of Minnesota, St. Paul, MN 55108, USA
| | - Brendan Epstein
- 2Department of Plant and Microbial Biology, University of Minnesota, St. Paul, MN 55108, USA
| | - Peter Tiffin
- 2Department of Plant and Microbial Biology, University of Minnesota, St. Paul, MN 55108, USA
| | - Michael J Sadowsky
- 1Biotechnology Institute and Department of Soil, Water, and Climate, University of Minnesota, St. Paul, MN 55108, USA
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35
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diCenzo GC, Benedict AB, Fondi M, Walker GC, Finan TM, Mengoni A, Griffitts JS. Robustness encoded across essential and accessory replicons of the ecologically versatile bacterium Sinorhizobium meliloti. PLoS Genet 2018; 14:e1007357. [PMID: 29672509 PMCID: PMC5929573 DOI: 10.1371/journal.pgen.1007357] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 05/01/2018] [Accepted: 04/10/2018] [Indexed: 11/19/2022] Open
Abstract
Bacterial genome evolution is characterized by gains, losses, and rearrangements of functional genetic segments. The extent to which large-scale genomic alterations influence genotype-phenotype relationships has not been investigated in a high-throughput manner. In the symbiotic soil bacterium Sinorhizobium meliloti, the genome is composed of a chromosome and two large extrachromosomal replicons (pSymA and pSymB, which together constitute 45% of the genome). Massively parallel transposon insertion sequencing (Tn-seq) was employed to evaluate the contributions of chromosomal genes to growth fitness in both the presence and absence of these extrachromosomal replicons. Ten percent of chromosomal genes from diverse functional categories are shown to genetically interact with pSymA and pSymB. These results demonstrate the pervasive robustness provided by the extrachromosomal replicons, which is further supported by constraint-based metabolic modeling. A comprehensive picture of core S. meliloti metabolism was generated through a Tn-seq-guided in silico metabolic network reconstruction, producing a core network encompassing 726 genes. This integrated approach facilitated functional assignments for previously uncharacterized genes, while also revealing that Tn-seq alone missed over a quarter of wild-type metabolism. This work highlights the many functional dependencies and epistatic relationships that may arise between bacterial replicons and across a genome, while also demonstrating how Tn-seq and metabolic modeling can be used together to yield insights not obtainable by either method alone. S. meliloti, which has traditionally facilitated ground-breaking insights into symbiotic communication, is also emerging as an excellent model for studying the evolution of functional relationships between bacterial chromosomes and anciently acquired accessory replicons. Multi-replicon genome architecture is present in ~ 10% of presently sequenced bacterial genomes. The S. meliloti genome is composed of three circular replicons, two of which are dispensable even though they encompass nearly half of the protein-coding genes in this organism. The construction of strains lacking these replicons has enabled a straightforward, genome-wide analysis of interactions between the chromosome and the non-essential replicons, revealing extensive functional cooperation between these genomic components. This analysis enabled a substantial refinement of a metabolic network model for S. meliloti. The integration of massively parallel genotype-phenotype screening with in silico metabolic reconstruction has enhanced our understanding of metabolic network structure as it relates to genome evolution in S. meliloti, and exemplifies an approach that may be productively applied to other taxa. The combined experimental and computational approach employed here further provides unique insights into the pervasive genetic interactions that may exist within large bacterial genomes.
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Affiliation(s)
- George C. diCenzo
- Department of Biology, University of Florence, Sesto Fiorentino, FI, Italy
- * E-mail:
| | - Alex B. Benedict
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT, United States of America
| | - Marco Fondi
- Department of Biology, University of Florence, Sesto Fiorentino, FI, Italy
| | - Graham C. Walker
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, United States of America
| | | | - Alessio Mengoni
- Department of Biology, University of Florence, Sesto Fiorentino, FI, Italy
| | - Joel S. Griffitts
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT, United States of America
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Sánchez-Cañizares C, Jorrín B, Durán D, Nadendla S, Albareda M, Rubio-Sanz L, Lanza M, González-Guerrero M, Prieto RI, Brito B, Giglio MG, Rey L, Ruiz-Argüeso T, Palacios JM, Imperial J. Genomic Diversity in the Endosymbiotic Bacterium Rhizobium leguminosarum. Genes (Basel) 2018; 9:E60. [PMID: 29364862 PMCID: PMC5852556 DOI: 10.3390/genes9020060] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 01/16/2018] [Accepted: 01/22/2018] [Indexed: 12/22/2022] Open
Abstract
Rhizobium leguminosarum bv. viciae is a soil α-proteobacterium that establishes a diazotrophic symbiosis with different legumes of the Fabeae tribe. The number of genome sequences from rhizobial strains available in public databases is constantly increasing, although complete, fully annotated genome structures from rhizobial genomes are scarce. In this work, we report and analyse the complete genome of R. leguminosarum bv. viciae UPM791. Whole genome sequencing can provide new insights into the genetic features contributing to symbiotically relevant processes such as bacterial adaptation to the rhizosphere, mechanisms for efficient competition with other bacteria, and the ability to establish a complex signalling dialogue with legumes, to enter the root without triggering plant defenses, and, ultimately, to fix nitrogen within the host. Comparison of the complete genome sequences of two strains of R. leguminosarum bv. viciae, 3841 and UPM791, highlights the existence of different symbiotic plasmids and a common core chromosome. Specific genomic traits, such as plasmid content or a distinctive regulation, define differential physiological capabilities of these endosymbionts. Among them, strain UPM791 presents unique adaptations for recycling the hydrogen generated in the nitrogen fixation process.
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Affiliation(s)
- Carmen Sánchez-Cañizares
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)—Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus de Montegancedo UPM, 28223 Madrid, Spain; (C.S.-C.); (B.J.); (D.D.); (M.A.); (L.R.-S.); (M.L.); (M.G.-G.); (R.I.P.); (B.B.); (L.R.)
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaría y de Biosistemas, Universidad Politécnica de Madrid (UPM), 28040 Madrid, Spain
- Department of Plant Sciences, University of Oxford, South Parks Road, OX1 3RB Oxford, UK
| | - Beatriz Jorrín
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)—Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus de Montegancedo UPM, 28223 Madrid, Spain; (C.S.-C.); (B.J.); (D.D.); (M.A.); (L.R.-S.); (M.L.); (M.G.-G.); (R.I.P.); (B.B.); (L.R.)
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaría y de Biosistemas, Universidad Politécnica de Madrid (UPM), 28040 Madrid, Spain
- Department of Plant Sciences, University of Oxford, South Parks Road, OX1 3RB Oxford, UK
| | - David Durán
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)—Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus de Montegancedo UPM, 28223 Madrid, Spain; (C.S.-C.); (B.J.); (D.D.); (M.A.); (L.R.-S.); (M.L.); (M.G.-G.); (R.I.P.); (B.B.); (L.R.)
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaría y de Biosistemas, Universidad Politécnica de Madrid (UPM), 28040 Madrid, Spain
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid (UAM), Ciudad Universitaria de Cantoblanco, Calle Francisco Tomás y Valiente 7, 28049 Madrid, Spain
| | - Suvarna Nadendla
- Institute for Genome Sciences (IGS), University of Maryland School of Medicine, Baltimore, MD 21201, USA; (S.N.); (M.G.G.)
| | - Marta Albareda
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)—Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus de Montegancedo UPM, 28223 Madrid, Spain; (C.S.-C.); (B.J.); (D.D.); (M.A.); (L.R.-S.); (M.L.); (M.G.-G.); (R.I.P.); (B.B.); (L.R.)
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaría y de Biosistemas, Universidad Politécnica de Madrid (UPM), 28040 Madrid, Spain
| | - Laura Rubio-Sanz
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)—Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus de Montegancedo UPM, 28223 Madrid, Spain; (C.S.-C.); (B.J.); (D.D.); (M.A.); (L.R.-S.); (M.L.); (M.G.-G.); (R.I.P.); (B.B.); (L.R.)
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaría y de Biosistemas, Universidad Politécnica de Madrid (UPM), 28040 Madrid, Spain
| | - Mónica Lanza
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)—Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus de Montegancedo UPM, 28223 Madrid, Spain; (C.S.-C.); (B.J.); (D.D.); (M.A.); (L.R.-S.); (M.L.); (M.G.-G.); (R.I.P.); (B.B.); (L.R.)
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaría y de Biosistemas, Universidad Politécnica de Madrid (UPM), 28040 Madrid, Spain
| | - Manuel González-Guerrero
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)—Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus de Montegancedo UPM, 28223 Madrid, Spain; (C.S.-C.); (B.J.); (D.D.); (M.A.); (L.R.-S.); (M.L.); (M.G.-G.); (R.I.P.); (B.B.); (L.R.)
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaría y de Biosistemas, Universidad Politécnica de Madrid (UPM), 28040 Madrid, Spain
| | - Rosa Isabel Prieto
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)—Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus de Montegancedo UPM, 28223 Madrid, Spain; (C.S.-C.); (B.J.); (D.D.); (M.A.); (L.R.-S.); (M.L.); (M.G.-G.); (R.I.P.); (B.B.); (L.R.)
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaría y de Biosistemas, Universidad Politécnica de Madrid (UPM), 28040 Madrid, Spain
| | - Belén Brito
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)—Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus de Montegancedo UPM, 28223 Madrid, Spain; (C.S.-C.); (B.J.); (D.D.); (M.A.); (L.R.-S.); (M.L.); (M.G.-G.); (R.I.P.); (B.B.); (L.R.)
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaría y de Biosistemas, Universidad Politécnica de Madrid (UPM), 28040 Madrid, Spain
| | - Michelle G. Giglio
- Institute for Genome Sciences (IGS), University of Maryland School of Medicine, Baltimore, MD 21201, USA; (S.N.); (M.G.G.)
| | - Luis Rey
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)—Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus de Montegancedo UPM, 28223 Madrid, Spain; (C.S.-C.); (B.J.); (D.D.); (M.A.); (L.R.-S.); (M.L.); (M.G.-G.); (R.I.P.); (B.B.); (L.R.)
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaría y de Biosistemas, Universidad Politécnica de Madrid (UPM), 28040 Madrid, Spain
| | - Tomás Ruiz-Argüeso
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)—Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus de Montegancedo UPM, 28223 Madrid, Spain; (C.S.-C.); (B.J.); (D.D.); (M.A.); (L.R.-S.); (M.L.); (M.G.-G.); (R.I.P.); (B.B.); (L.R.)
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaría y de Biosistemas, Universidad Politécnica de Madrid (UPM), 28040 Madrid, Spain
| | - José M. Palacios
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)—Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus de Montegancedo UPM, 28223 Madrid, Spain; (C.S.-C.); (B.J.); (D.D.); (M.A.); (L.R.-S.); (M.L.); (M.G.-G.); (R.I.P.); (B.B.); (L.R.)
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaría y de Biosistemas, Universidad Politécnica de Madrid (UPM), 28040 Madrid, Spain
| | - Juan Imperial
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)—Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus de Montegancedo UPM, 28223 Madrid, Spain; (C.S.-C.); (B.J.); (D.D.); (M.A.); (L.R.-S.); (M.L.); (M.G.-G.); (R.I.P.); (B.B.); (L.R.)
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaría y de Biosistemas, Universidad Politécnica de Madrid (UPM), 28040 Madrid, Spain
- Instituto de Ciencias Agrarias, Consejo Superior de Investigaciones Científicas (CSIC), Serrano 115 bis, 28006 Madrid, Spain
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Effective removal of a range of Ti/Ri plasmids using a pBBR1-type vector having a repABC operon and a lux reporter system. Appl Microbiol Biotechnol 2018; 102:1823-1836. [PMID: 29318333 DOI: 10.1007/s00253-017-8721-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 12/09/2017] [Accepted: 12/15/2017] [Indexed: 10/18/2022]
Abstract
Ti and Ri plasmids of pathogenic Agrobacterium strains are stably maintained by the function of a repABC operon and have been classified into four incompatibility groups, namely, incRh1, incRh2, incRh3, and incRh4. Removal of these plasmids from their bacterial cells is an important step in determining strain-specific virulence characteristics and to construct strains useful for transformation. Here, we developed two powerful tools to improve this process. We first established a reporter system to detect the presence and absence of Ti/Ri plasmids in cells by using an acetosyringone (AS)-inducible promoter of the Ti2 small RNA and luxAB from Vibrio harveyi. This system distinguished a Ti/Ri plasmid-free cell colony among plasmid-harboring cell colonies by causing the latter colonies to emit light in response to AS. We then constructed new "Ti/Ri eviction plasmids," each of which carries a repABC from one of four Ti/Ri plasmids that belonged to incRh1, incRh2, incRh3, and incRh4 groups in the suicidal plasmid pK18mobsacB and in a broad-host-range pBBR1 vector. Introduction of the new eviction plasmids into Agrobacterium cells harboring the corresponding Ti/Ri plasmids led to Ti/Ri plasmid-free cells in every incRh group. The Ti/Ri eviction was more effective by plasmids with the pBBR1 backbone than by those with the pK18mobsacB backbone. Furthermore, the highly stable cryptic plasmid pAtC58 in A. tumefaciens C58 was effectively evicted by the introduction of a pBBR1 vector containing the repABC of pAtC58. These results indicate that the set of pBBR1-repABC plasmids is a powerful tool for the removal of stable rhizobial plasmids.
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38
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The Completed PacBio Single-Molecule Real-Time Sequence of Methylosinus trichosporium Strain OB3b Reveals the Presence of a Third Large Plasmid. GENOME ANNOUNCEMENTS 2017; 5:5/49/e01349-17. [PMID: 29217796 PMCID: PMC5721141 DOI: 10.1128/genomea.01349-17] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Presented here is the complete genome sequence of the well-studied Rhizobiales methanotroph Methylosinus trichosporium strain OB3b. The assembly contains 5,183,433 bp, corresponding to a chromosome of 4,508,832 bp and three circular plasmids of 285,280 bp, 209,102 bp, and 180,219 bp.
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39
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Small Noncoding RNA AbcR1 Addressing Multiple Target mRNAs From Transcriptional Factor and Two-Component Response Regulator of Brucella melitensis. Jundishapur J Microbiol 2017. [DOI: 10.5812/jjm.60269] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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40
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Liu J, Yang L, Chen D, Peters BM, Li L, Li B, Xu Z, Shirtliff ME. Complete sequence of pBM413, a novel multidrug resistance megaplasmid carrying qnrVC6 and bla IMP-45 from pseudomonas aeruginosa. Int J Antimicrob Agents 2017; 51:145-150. [PMID: 28923459 DOI: 10.1016/j.ijantimicag.2017.09.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 09/01/2017] [Accepted: 09/10/2017] [Indexed: 11/27/2022]
Abstract
This study aimed to characterise a novel multidrug resistance megaplasmid carrying qnrVC6 and blaIMP-45 from Pseudomonas aeruginosa strain Guangzhou-Pae617 isolated from a patient hospitalised in Guangzhou, China, in 2012. The plasmid pBM413 has a length of 423 017 bp and an average G + C content of 56.41%. A qnrVC6 gene flanked by two copies of insertion sequence (IS) elements ISCR1, a multiresistance class 1 integron In786 containing aacA4-blaIMP-45-blaOXA-1-catB3 cassettes, an armA gene, and an aphA7 gene flanked by two copies of IS26 were identified. To our knowledge, this is the first identification of a qnrVC6 gene in P. aeruginosa.
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Affiliation(s)
- Junyan Liu
- School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, China
| | - Ling Yang
- Department of Laboratory Medicine, First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China
| | - Dingqiang Chen
- Department of Laboratory Medicine, First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China.
| | - Brian M Peters
- Department of Clinical Pharmacy, College of Pharmacy, University of Tennessee Health Sciences Center, Memphis, TN 38163, USA
| | - Lin Li
- School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, China
| | - Bing Li
- School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, China
| | - Zhenbo Xu
- School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, China; Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA.
| | - Mark E Shirtliff
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA
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diCenzo GC, Finan TM. The Divided Bacterial Genome: Structure, Function, and Evolution. Microbiol Mol Biol Rev 2017; 81:e00019-17. [PMID: 28794225 PMCID: PMC5584315 DOI: 10.1128/mmbr.00019-17] [Citation(s) in RCA: 135] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Approximately 10% of bacterial genomes are split between two or more large DNA fragments, a genome architecture referred to as a multipartite genome. This multipartite organization is found in many important organisms, including plant symbionts, such as the nitrogen-fixing rhizobia, and plant, animal, and human pathogens, including the genera Brucella, Vibrio, and Burkholderia. The availability of many complete bacterial genome sequences means that we can now examine on a broad scale the characteristics of the different types of DNA molecules in a genome. Recent work has begun to shed light on the unique properties of each class of replicon, the unique functional role of chromosomal and nonchromosomal DNA molecules, and how the exploitation of novel niches may have driven the evolution of the multipartite genome. The aims of this review are to (i) outline the literature regarding bacterial genomes that are divided into multiple fragments, (ii) provide a meta-analysis of completed bacterial genomes from 1,708 species as a way of reviewing the abundant information present in these genome sequences, and (iii) provide an encompassing model to explain the evolution and function of the multipartite genome structure. This review covers, among other topics, salient genome terminology; mechanisms of multipartite genome formation; the phylogenetic distribution of multipartite genomes; how each part of a genome differs with respect to genomic signatures, genetic variability, and gene functional annotation; how each DNA molecule may interact; as well as the costs and benefits of this genome structure.
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Affiliation(s)
- George C diCenzo
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Turlough M Finan
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
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Characterization of Sinorhizobium sp. LM21 Prophages and Virus-Encoded DNA Methyltransferases in the Light of Comparative Genomic Analyses of the Sinorhizobial Virome. Viruses 2017; 9:v9070161. [PMID: 28672885 PMCID: PMC5537653 DOI: 10.3390/v9070161] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Revised: 06/19/2017] [Accepted: 06/21/2017] [Indexed: 02/06/2023] Open
Abstract
The genus Sinorhizobium/Ensifer mostly groups nitrogen-fixing bacteria that create root or stem nodules on leguminous plants and transform atmospheric nitrogen into ammonia, which improves the productivity of the plants. Although these biotechnologically-important bacteria are commonly found in various soil environments, little is known about their phages. In this study, the genome of Sinorhizobium sp. LM21 isolated from a heavy-metal-contaminated copper mine in Poland was investigated for the presence of prophages and DNA methyltransferase-encoding genes. In addition to the previously identified temperate phage, ΦLM21, and the phage-plasmid, pLM21S1, the analysis revealed the presence of three prophage regions. Moreover, four novel phage-encoded DNA methyltransferase (MTase) genes were identified and the enzymes were characterized. It was shown that two of the identified viral MTases methylated the same target sequence (GANTC) as cell cycle-regulated methyltransferase (CcrM) of the bacterial host strain, LM21. This discovery was recognized as an example of the evolutionary convergence between enzymes of sinorhizobial viruses and their host, which may play an important role in virus cycle. In the last part of the study, thorough comparative analyses of 31 sinorhizobial (pro)phages (including active sinorhizobial phages and novel putative prophages retrieved and manually re-annotated from Sinorhizobium spp. genomes) were performed. The networking analysis revealed the presence of highly conserved proteins (e.g., holins and endolysins) and a high diversity of viral integrases. The analysis also revealed a large number of viral DNA MTases, whose genes were frequently located within the predicted replication modules of analyzed prophages, which may suggest their important regulatory role. Summarizing, complex analysis of the phage protein similarity network enabled a new insight into overall sinorhizobial virome diversity.
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Döhlemann J, Wagner M, Happel C, Carrillo M, Sobetzko P, Erb TJ, Thanbichler M, Becker A. A Family of Single Copy repABC-Type Shuttle Vectors Stably Maintained in the Alpha-Proteobacterium Sinorhizobium meliloti. ACS Synth Biol 2017; 6:968-984. [PMID: 28264559 PMCID: PMC7610768 DOI: 10.1021/acssynbio.6b00320] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
![]()
A considerable
share of bacterial species maintains segmented genomes.
Plant symbiotic α-proteobacterial rhizobia contain up to six repABC-type replicons in addition to the primary chromosome.
These low or unit-copy replicons, classified as secondary chromosomes,
chromids, or megaplasmids, are exclusively found in α-proteobacteria.
Replication and faithful partitioning of these replicons to the daughter
cells is mediated by the repABC region. The importance
of α-rhizobial symbiotic nitrogen fixation for sustainable agriculture
and Agrobacterium-mediated plant transformation as
a tool in plant sciences has increasingly moved biological engineering
of these organisms into focus. Plasmids are ideal DNA-carrying vectors
for these engineering efforts. On the basis of repABC regions collected from α-rhizobial secondary replicons, and
origins of replication derived from traditional cloning vectors, we
devised the versatile family of pABC shuttle vectors propagating in Sinorhizobium meliloti, related members of the Rhizobiales, and Escherichia coli. A modular plasmid library
providing the elemental parts for pABC vector assembly was founded.
The standardized design of these vectors involves five basic modules:
(1) repABC cassette, (2) plasmid-derived origin of
replication, (3) RK2/RP4 mobilization site (optional), (4) antibiotic
resistance gene, and (5) multiple cloning site flanked by transcription
terminators. In S. meliloti, pABC vectors showed
high propagation stability and unit-copy number. We demonstrated stable
coexistence of three pABC vectors in addition to the two indigenous
megaplasmids in S. meliloti, suggesting combinability
of multiple compatible pABC plasmids. We further devised an in vivo cloning strategy involving Cre/lox-mediated translocation of large DNA fragments to an autonomously
replicating repABC-based vector, followed by conjugation-mediated
transfer either to compatible rhizobia or E. coli.
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Affiliation(s)
- Johannes Döhlemann
- LOEWE Center for Synthetic Microbiology, Marburg, 35043, Germany
- Faculty of Biology, Philipps-Universität Marburg, Marburg, 35043, Germany
| | - Marcel Wagner
- LOEWE Center for Synthetic Microbiology, Marburg, 35043, Germany
- Faculty of Biology, Philipps-Universität Marburg, Marburg, 35043, Germany
| | - Carina Happel
- LOEWE Center for Synthetic Microbiology, Marburg, 35043, Germany
- Faculty of Biology, Philipps-Universität Marburg, Marburg, 35043, Germany
| | - Martina Carrillo
- LOEWE Center for Synthetic Microbiology, Marburg, 35043, Germany
- Biochemistry and Synthetic Biology of Microbial Metabolism Group, Max Planck Institute for Terrestrial Microbiology, Marburg, 35043, Germany
| | - Patrick Sobetzko
- LOEWE Center for Synthetic Microbiology, Marburg, 35043, Germany
| | - Tobias J. Erb
- LOEWE Center for Synthetic Microbiology, Marburg, 35043, Germany
- Biochemistry and Synthetic Biology of Microbial Metabolism Group, Max Planck Institute for Terrestrial Microbiology, Marburg, 35043, Germany
| | - Martin Thanbichler
- LOEWE Center for Synthetic Microbiology, Marburg, 35043, Germany
- Faculty of Biology, Philipps-Universität Marburg, Marburg, 35043, Germany
| | - Anke Becker
- LOEWE Center for Synthetic Microbiology, Marburg, 35043, Germany
- Faculty of Biology, Philipps-Universität Marburg, Marburg, 35043, Germany
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Genetic (In)stability of 2,6-Dichlorobenzamide Catabolism in Aminobacter sp. Strain MSH1 Biofilms under Carbon Starvation Conditions. Appl Environ Microbiol 2017; 83:AEM.00137-17. [PMID: 28363960 DOI: 10.1128/aem.00137-17] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 03/24/2017] [Indexed: 01/07/2023] Open
Abstract
Aminobacter sp. strain MSH1 grows on and mineralizes the groundwater micropollutant 2,6-dichlorobenzamide (BAM) and is of interest for BAM removal in drinking water treatment plants (DWTPs). The BAM-catabolic genes in MSH1 are located on plasmid pBAM1, carrying bbdA, which encodes the conversion of BAM to 2,6-dichlorobenzoic acid (2,6-DCBA) (BbdA+ phenotype), and plasmid pBAM2, carrying gene clusters encoding the conversion of 2,6-DCBA to tricarboxylic acid (TCA) cycle intermediates (Dcba+ phenotype). There are indications that MSH1 easily loses its BAM-catabolic phenotype. We obtained evidence that MSH1 rapidly develops a population that lacks the ability to mineralize BAM when grown on nonselective (R2B medium) and semiselective (R2B medium with BAM) media. Lack of mineralization was explained by loss of the Dcba+ phenotype and corresponding genes. The ecological significance of this instability for the use of MSH1 for BAM removal in the oligotrophic environment of DWTPs was explored in lab and pilot systems. A higher incidence of BbdA+ Dcba- MSH1 cells was also observed when MSH1 was grown as a biofilm in flow chambers under C and N starvation conditions due to growth on nonselective residual assimilable organic carbon. Similar observations were made in experiments with a pilot sand filter reactor bioaugmented with MSH1. BAM conversion to 2,6-DCBA was not affected by loss of the DCBA-catabolic genes. Our results show that MSH1 is prone to BAM-catabolic instability under the conditions occurring in a DWTP. While conversion of BAM to 2,6-DCBA remains unaffected, BAM mineralization activity is at risk, and monitoring of metabolites is warranted.IMPORTANCE Bioaugmentation of dedicated biofiltration units with bacterial strains that grow on and mineralize micropollutants was suggested as an alternative for treating micropollutant-contaminated water in drinking water treatment plants (DWTPs). Organic-pollutant-catabolic genes in bacteria are often easily lost, especially under nonselective conditions, which affects the bioaugmentation success. In this study, we provide evidence that Aminobacter sp. strain MSH1, which uses the common groundwater micropollutant 2,6-dichlorobenzamide (BAM) as a C source, shows a high frequency of loss of its BAM-mineralizing phenotype due to the loss of genes that convert 2,6-DCBA to Krebs cycle intermediates when nonselective conditions occur. Moreover, we show that catabolic-gene loss also occurs in the oligotrophic environment of DWTPs, where growth of MSH1 depends mainly on the high fluxes of low concentrations of assimilable organic carbon, and hence show the ecological relevance of catabolic instability for using strain MSH1 for BAM removal in DWTPs.
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Thomas CM, Thomson NR, Cerdeño-Tárraga AM, Brown CJ, Top EM, Frost LS. Annotation of plasmid genes. Plasmid 2017; 91:61-67. [PMID: 28365184 DOI: 10.1016/j.plasmid.2017.03.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 03/23/2017] [Indexed: 10/19/2022]
Abstract
Good annotation of plasmid genomes is essential to maximise the value of the rapidly increasing volume of plasmid sequences. This short review highlights some of the current issues and suggests some ways forward. Where a well-studied related plasmid system exists we recommend that new annotation adheres to the convention already established for that system, so long as it is based on sound principles and solid experimental evidence, even if some of the new genes are more similar to homologues in different systems. Where a well-established model does not exist we provide generic gene names that reflect likely biochemical activity rather than overall purpose particularly, for example, where genes clearly belong to a type IV secretion system but it is not known whether they function in conjugative transfer or virulence. We also recommend that annotators use a whole system naming approach to avoid ending up with an illogical mixture of names from other systems based on the highest scoring match from a BLAST search. In addition, where function has not been experimentally established we recommend using just the locus tag, rather than a function-related gene name, while recording possible functions as notes rather than in a provisional name.
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Affiliation(s)
- Christopher M Thomas
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
| | | | | | - Celeste J Brown
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844-3051, United States
| | - Eva M Top
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844-3051, United States
| | - Laura S Frost
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
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46
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Yamamoto S, Agustina V, Sakai A, Moriguchi K, Suzuki K. An extra repABC locus in the incRh2 Ti plasmid pTiBo542 exerts incompatibility toward an incRh1 plasmid. Plasmid 2017; 90:20-29. [PMID: 28238706 DOI: 10.1016/j.plasmid.2017.02.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 01/26/2017] [Accepted: 02/13/2017] [Indexed: 10/20/2022]
Abstract
Ti/Ri plasmids in pathogenic Agrobacterium species are repABC replicons that are stably maintained by the function of repABC genes. Two Ti plasmids, pTiBo542 and pTiS4, belonging to incRh2 and incRh4 incompatibility groups, respectively, were reported to carry two repABC loci. In the present study, to reveal the roles of the two repABC loci in the two plasmids, we constructed mini-replicons carrying any one or both of the repABC loci (referred to as repABC1 and repABC2 here) and examined their replication and incompatibility properties. The introduction of mini-replicons into A. tumefaciens C58C1 strains suggested that repABC1 functions as replicator genes but repABC2 does not in both the Ti plasmids. Because the components of repABC2 of pTiBo542 have highly similar amino acid and nucleotide sequences to those of the incRh1-type repABC replicon, we introduced repABC2-containing replicons into cells harboring an incRh1 plasmid in order to check their incompatibility traits. As a result, the repABC2-containing replicon expelled the resident incRh1 plasmid, indicating that the extra repABC locus is dispensable for replication and could work as an incompatibility determinant against incRh1 group plasmids. We suggest that the locus contributes to plasmid retention by eliminating the burden of co-existing competitive plasmids in host cells through its incompatibility.
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Affiliation(s)
- Shinji Yamamoto
- Department of Biological Science, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan.
| | - Vita Agustina
- Department of Biological Science, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Ayako Sakai
- Department of Biological Science, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Kazuki Moriguchi
- Department of Biological Science, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Katsunori Suzuki
- Department of Biological Science, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526, Japan
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48
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Grote J, Krysciak D, Petersen K, Güllert S, Schmeisser C, Förstner KU, Krishnan HB, Schwalbe H, Kubatova N, Streit WR. The Absence of the N-acyl-homoserine-lactone Autoinducer Synthase Genes traI and ngrI Increases the Copy Number of the Symbiotic Plasmid in Sinorhizobium fredii NGR234. Front Microbiol 2016; 7:1858. [PMID: 27917168 PMCID: PMC5114275 DOI: 10.3389/fmicb.2016.01858] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 11/04/2016] [Indexed: 01/24/2023] Open
Abstract
Plant-released flavonoids induce the transcription of symbiotic genes in rhizobia and one of the first bacterial responses is the synthesis of so called Nod factors. They are responsible for the initial root hair curling during onset of root nodule development. This signal exchange is believed to be essential for initiating the plant symbiosis with rhizobia affiliated with the Alphaproteobacteria. Here, we provide evidence that in the broad host range strain Sinorhizobium fredii NGR234 the complete lack of quorum sensing molecules results in an elevated copy number of its symbiotic plasmid (pNGR234a). This in turn triggers the expression of symbiotic genes and the production of Nod factors in the absence of plant signals. Therefore, increasing the copy number of specific plasmids could be a widespread mechanism of specialized bacterial populations to bridge gaps in signaling cascades.
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Affiliation(s)
- Jessica Grote
- Department of Microbiology and Biotechnology, Biocenter Klein Flottbek, University of Hamburg Hamburg, Germany
| | - Dagmar Krysciak
- Department of Microbiology and Biotechnology, Biocenter Klein Flottbek, University of Hamburg Hamburg, Germany
| | - Katrin Petersen
- Department of Microbiology and Biotechnology, Biocenter Klein Flottbek, University of Hamburg Hamburg, Germany
| | - Simon Güllert
- Department of Microbiology and Biotechnology, Biocenter Klein Flottbek, University of Hamburg Hamburg, Germany
| | - Christel Schmeisser
- Department of Microbiology and Biotechnology, Biocenter Klein Flottbek, University of Hamburg Hamburg, Germany
| | - Konrad U Förstner
- Core Unit Systems Medicine, University of Würzburg Würzburg, Germany
| | - Hari B Krishnan
- Plant Genetics Research Unit, Agricultural Research Service, United States Department of Agriculture, University of Missouri Columbia, MO, USA
| | - Harald Schwalbe
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance Johann Wolfgang Goethe-University Frankfurt, Germany
| | - Nina Kubatova
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance Johann Wolfgang Goethe-University Frankfurt, Germany
| | - Wolfgang R Streit
- Department of Microbiology and Biotechnology, Biocenter Klein Flottbek, University of Hamburg Hamburg, Germany
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Tabata M, Ohhata S, Nikawadori Y, Kishida K, Sato T, Kawasumi T, Kato H, Ohtsubo Y, Tsuda M, Nagata Y. Comparison of the complete genome sequences of four γ-hexachlorocyclohexane-degrading bacterial strains: insights into the evolution of bacteria able to degrade a recalcitrant man-made pesticide. DNA Res 2016; 23:581-599. [PMID: 27581378 PMCID: PMC5144681 DOI: 10.1093/dnares/dsw041] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 07/09/2016] [Indexed: 11/20/2022] Open
Abstract
γ-Hexachlorocyclohexane (γ-HCH) is a recalcitrant man-made chlorinated pesticide. Here, the complete genome sequences of four γ-HCH-degrading sphingomonad strains, which are most unlikely to have been derived from one ancestral γ-HCH degrader, were compared. Together with several experimental data, we showed that (i) all the four strains carry almost identical linA to linE genes for the conversion of γ-HCH to maleylacetate (designated “specific” lin genes), (ii) considerably different genes are used for the metabolism of maleylacetate in one of the four strains, and (iii) the linKLMN genes for the putative ABC transporter necessary for γ-HCH utilization exhibit structural divergence, which reflects the phylogenetic relationship of their hosts. Replicon organization and location of the lin genes in the four genomes are significantly different with one another, and that most of the specific lin genes are located on multiple sphingomonad-unique plasmids. Copies of IS6100, the most abundant insertion sequence in the four strains, are often located in close proximity to the specific lin genes. Analysis of the footprints of target duplication upon IS6100 transposition and the experimental detection of IS6100 transposition strongly suggested that the IS6100 transposition has caused dynamic genome rearrangements and the diversification of lin-flanking regions in the four strains.
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Affiliation(s)
- Michiro Tabata
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan
| | - Satoshi Ohhata
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan
| | - Yuki Nikawadori
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan
| | - Kouhei Kishida
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan
| | - Takuya Sato
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan
| | - Toru Kawasumi
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan
| | - Hiromi Kato
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan
| | - Yoshiyuki Ohtsubo
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan
| | - Masataka Tsuda
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan
| | - Yuji Nagata
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan
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Koper P, Żebracki K, Marczak M, Skorupska A, Mazur A. RepB proteins of the multipartite Rhizobium leguminosarum bv. trifolii genome discriminate between centromere-like parS sequences for plasmid segregational stability. Mol Microbiol 2016; 102:446-466. [PMID: 27480612 DOI: 10.1111/mmi.13472] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/25/2016] [Indexed: 11/28/2022]
Abstract
The plasmids of the Rhizobiaceae family members and other Alphaproteobacteria are usually large, low copy-number and contain all elements necessary for active segregation and replication located in one operon comprising repABC genes. The genome of Rhizobium leguminosarum bv. trifolii TA1 (RtTA1) consists of a chromosome and four plasmids (pRleTA1a-d) with repABC operons. In this work, centromere-binding RepB proteins of four RtTA1 plasmids were studied. Stability assays of the truncated derivatives of repABC cassettes demonstrated that RepA, RepB proteins and parS-like elements constituted plasmid partitioning systems, while RepC were sufficient for their replication. Individual RepB proteins bound specifically to centromere-like parS elements of the parental plasmids, which was crucial step toward the proper segregation of plasmids into daughter cells. RtTA1 RepB proteins formed dimers and oligomers in the solution. The C-terminal part of RepB was responsible for dimerization, while the domain engaged in parS binding was located in the middle of the protein. It was concluded that the specific interaction between individual RepB proteins and their target sequences together with the substantial diversity of the Rep proteins and parS originating from different plasmids strongly contributed to the coexistence of several plasmids equipped with similar repABC cassettes in the multipartite bacterial genome.
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Affiliation(s)
- Piotr Koper
- Department of Genetics and Microbiology, Institute of Microbiology and Biotechnology, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Lublin, Poland
| | - Kamil Żebracki
- Department of Genetics and Microbiology, Institute of Microbiology and Biotechnology, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Lublin, Poland
| | - Małgorzata Marczak
- Department of Genetics and Microbiology, Institute of Microbiology and Biotechnology, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Lublin, Poland
| | - Anna Skorupska
- Department of Genetics and Microbiology, Institute of Microbiology and Biotechnology, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Lublin, Poland
| | - Andrzej Mazur
- Department of Genetics and Microbiology, Institute of Microbiology and Biotechnology, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Lublin, Poland.
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