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Zhang P, Zhang B, Ji Y, Jiao J, Zhang Z, Tian C. Cofitness network connectivity determines a fuzzy essential zone in open bacterial pangenome. MLIFE 2024; 3:277-290. [PMID: 38948139 PMCID: PMC11211677 DOI: 10.1002/mlf2.12132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 04/20/2024] [Accepted: 04/24/2024] [Indexed: 07/02/2024]
Abstract
Most in silico evolutionary studies commonly assumed that core genes are essential for cellular function, while accessory genes are dispensable, particularly in nutrient-rich environments. However, this assumption is seldom tested genetically within the pangenome context. In this study, we conducted a robust pangenomic Tn-seq analysis of fitness genes in a nutrient-rich medium for Sinorhizobium strains with a canonical open pangenome. To evaluate the robustness of fitness category assignment, Tn-seq data for three independent mutant libraries per strain were analyzed by three methods, which indicates that the Hidden Markov Model (HMM)-based method is most robust to variations between mutant libraries and not sensitive to data size, outperforming the Bayesian and Monte Carlo simulation-based methods. Consequently, the HMM method was used to classify the fitness category. Fitness genes, categorized as essential (ES), advantage (GA), and disadvantage (GD) genes for growth, are enriched in core genes, while nonessential genes (NE) are over-represented in accessory genes. Accessory ES/GA genes showed a lower fitness effect than core ES/GA genes. Connectivity degrees in the cofitness network decrease in the order of ES, GD, and GA/NE. In addition to accessory genes, 1599 out of 3284 core genes display differential essentiality across test strains. Within the pangenome core, both shared quasi-essential (ES and GA) and strain-dependent fitness genes are enriched in similar functional categories. Our analysis demonstrates a considerable fuzzy essential zone determined by cofitness connectivity degrees in Sinorhizobium pangenome and highlights the power of the cofitness network in understanding the genetic basis of ever-increasing prokaryotic pangenome data.
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Affiliation(s)
- Pan Zhang
- State Key Laboratory of Plant Environmental Resilience, and College of Biological SciencesChina Agricultural UniversityBeijingChina
- MOA Key Laboratory of Soil Microbiology, and Rhizobium Research CenterChina Agricultural UniversityBeijingChina
- Shenzhen Institute of Synthetic Biology, Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenChina
| | - Biliang Zhang
- MOA Key Laboratory of Soil Microbiology, and Rhizobium Research CenterChina Agricultural UniversityBeijingChina
- State Key Laboratory of Livestock and Poultry Biotechnology Breeding, and College of Biological SciencesChina Agricultural UniversityBeijingChina
| | - Yuan‐Yuan Ji
- State Key Laboratory of Plant Environmental Resilience, and College of Biological SciencesChina Agricultural UniversityBeijingChina
- MOA Key Laboratory of Soil Microbiology, and Rhizobium Research CenterChina Agricultural UniversityBeijingChina
| | - Jian Jiao
- State Key Laboratory of Plant Environmental Resilience, and College of Biological SciencesChina Agricultural UniversityBeijingChina
- MOA Key Laboratory of Soil Microbiology, and Rhizobium Research CenterChina Agricultural UniversityBeijingChina
| | - Ziding Zhang
- State Key Laboratory of Livestock and Poultry Biotechnology Breeding, and College of Biological SciencesChina Agricultural UniversityBeijingChina
| | - Chang‐Fu Tian
- State Key Laboratory of Plant Environmental Resilience, and College of Biological SciencesChina Agricultural UniversityBeijingChina
- MOA Key Laboratory of Soil Microbiology, and Rhizobium Research CenterChina Agricultural UniversityBeijingChina
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Carvia-Hermoso C, Cuéllar V, Bernabéu-Roda LM, van Dillewijn P, Soto MJ. Sinorhizobium meliloti GR4 Produces Chromosomal- and pSymA-Encoded Type IVc Pili That Influence the Interaction with Alfalfa Plants. PLANTS (BASEL, SWITZERLAND) 2024; 13:628. [PMID: 38475474 DOI: 10.3390/plants13050628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 02/09/2024] [Accepted: 02/23/2024] [Indexed: 03/14/2024]
Abstract
Type IVc Pili (T4cP), also known as Tad or Flp pili, are long thin microbial filaments that are made up of small-sized pilins. These appendages serve different functions in bacteria, including attachment, biofilm formation, surface sensing, motility, and host colonization. Despite their relevant role in diverse microbial lifestyles, knowledge about T4cP in bacteria that establish symbiosis with legumes, collectively referred to as rhizobia, is still limited. Sinorhizobium meliloti contains two clusters of T4cP-related genes: flp-1 and flp-2, which are located on the chromosome and the pSymA megaplasmid, respectively. Bundle-forming pili associated with flp-1 are involved in the competitive nodulation of alfalfa plants, but the role of flp-2 remains elusive. In this work, we have performed a comprehensive bioinformatic analysis of T4cP genes in the highly competitive S. meliloti GR4 strain and investigated the role of its flp clusters in pilus biogenesis, motility, and in the interaction with alfalfa. Single and double flp-cluster mutants were constructed on the wild-type genetic background as well as in a flagellaless derivative strain. Our data demonstrate that both chromosomal and pSymA flp clusters are functional in pili biogenesis and contribute to surface translocation and nodule formation efficiency in GR4. In this strain, the presence of flp-1 in the absence of flp-2 reduces the competitiveness for nodule occupation.
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Affiliation(s)
- Cristina Carvia-Hermoso
- Department of Biotechnology and Environmental Protection, Estación Experimental del Zaidín, CSIC, 18008 Granada, Spain
| | - Virginia Cuéllar
- Department of Biotechnology and Environmental Protection, Estación Experimental del Zaidín, CSIC, 18008 Granada, Spain
| | - Lydia M Bernabéu-Roda
- Department of Biotechnology and Environmental Protection, Estación Experimental del Zaidín, CSIC, 18008 Granada, Spain
| | - Pieter van Dillewijn
- Department of Biotechnology and Environmental Protection, Estación Experimental del Zaidín, CSIC, 18008 Granada, Spain
| | - María J Soto
- Department of Biotechnology and Environmental Protection, Estación Experimental del Zaidín, CSIC, 18008 Granada, Spain
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Han K, Li Y, Zhang Z, Sun L, Wang ET, Li Y. Comparative genome analysis of Sesbania cannabina-nodulating Rhizobium spp. revealing the symbiotic and transferrable characteristics of symbiosis plasmids. Microb Genom 2023; 9. [PMID: 37133904 DOI: 10.1099/mgen.0.001004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023] Open
Abstract
Symbiotic nitrogen fixation between legumes and rhizobia makes a great contribution to the terrestrial ecosystem. The successful symbiosis between the partners mainly depends on the nod and nif genes in rhizobia, while the specific symbiosis is mainly determined by the structure of Nod factors and the corresponding secretion systems (type III secretion system; T3SS), etc. These symbiosis genes are usually located on symbiotic plasmids or a chromosomal symbiotic island, both could be transferred interspecies. In our previous studies, Sesbania cannabina-nodulating rhizobia across the world were classified into 16 species of four genera and all the strains, especially those of Rhizobium spp., harboured extraordinarily highly conserved symbiosis genes, suggesting that horizontal transfer of symbiosis genes might have happened among them. In order to learn the genomic basis of diversification of rhizobia under the selection of host specificity, we performed this study to compare the complete genome sequences of four Rhizobium strains associated with S. cannabina, YTUBH007, YTUZZ027, YTUHZ044 and YTUHZ045. Their complete genomes were sequenced and assembled at the replicon level. Each strain represents a different species according to the average nucleotide identity (ANI) values calculated using the whole-genome sequences; furthermore, except for YTUBH007, which was classified as Rhizobium binae, the remaining three strains were identified as new candidate species. A single symbiotic plasmid sized 345-402 kb containing complete nod, nif, fix, T3SS and conjugal transfer genes was detected in each strain. The high ANI and amino acid identity (AAI) values, as well as the close phylogenetic relationships among the entire symbiotic plasmid sequences, indicate that they have the same origin and the entire plasmid has been transferred among different Rhizobium species. These results indicate that S. cannabina stringently selects a certain symbiosis gene background of the rhizobia for nodulation, which might have forced the symbiosis genes to transfer from some introduced rhizobia to the related native or local-condition-adapted bacteria. The existence of almost complete conjugal transfer related elements, but not the gene virD, indicated that the self-transfer of the symbiotic plasmid in these rhizobial strains may be realized via a virD-independent pathway or through another unidentified gene. This study provides insight for the better understanding of high-frequency symbiotic plasmid transfer, host-specific nodulation and the host shift for rhizobia.
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Affiliation(s)
- Kunming Han
- Yantai Key Laboratory of Characteristic Agricultural Bioresource Conservation & Germplasm Innovative Utilization, College of Life Sciences, Yantai University, Yantai, Shandong 264005, PR China
| | - Yan Li
- Yantai Key Laboratory of Characteristic Agricultural Bioresource Conservation & Germplasm Innovative Utilization, College of Life Sciences, Yantai University, Yantai, Shandong 264005, PR China
| | - Zhenpeng Zhang
- Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, PR China
| | - Liqin Sun
- Yantai Key Laboratory of Characteristic Agricultural Bioresource Conservation & Germplasm Innovative Utilization, College of Life Sciences, Yantai University, Yantai, Shandong 264005, PR China
| | - En Tao Wang
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City 11340, Mexico
| | - Yan Li
- Yantai Key Laboratory of Characteristic Agricultural Bioresource Conservation & Germplasm Innovative Utilization, College of Life Sciences, Yantai University, Yantai, Shandong 264005, PR China
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Molecular Mechanism of Chloramphenicol and Thiamphenicol Resistance Mediated by a Novel Oxidase, CmO, in Sphingomonadaceae. Appl Environ Microbiol 2023; 89:e0154722. [PMID: 36519886 PMCID: PMC9888274 DOI: 10.1128/aem.01547-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Antibiotic resistance mediated by bacterial enzyme inactivation plays a crucial role in the degradation of antibiotics in the environment. Chloramphenicol (CAP) resistance by enzymatic inactivation comprises nitro reduction, amide bond hydrolysis, and acetylation modification. However, the molecular mechanism of enzymatic oxidation of CAP remains unknown. Here, a novel oxidase gene, cmO, was identified and confirmed biochemically. The encoded CmO oxidase could catalyze the oxidation at the C-1' and C-3' positions of CAP and thiamphenicol (TAP) in Sphingobium sp. strain CAP-1. CmO is highly conserved in members of the family Sphingomonadaceae and shares the highest amino acid similarity of 41.05% with the biochemically identified glucose methanol choline (GMC) oxidoreductases. Molecular docking and site-directed mutagenesis analyses demonstrated that CAP was anchored inside the protein pocket of CmO with the hydrogen bonding of key residues glycine (G) 99, asparagine (N) 518, methionine (M) 474, and tyrosine (Y) 380. CAP sensitivity tests demonstrated that the acetyltransferase and CmO could enable a higher level of resistance to CAP than the amide bond-hydrolyzing esterase and nitroreductase. This study provides a better theoretical basis and a novel diagnostic gene for understanding and assessing the fate and resistance risk of CAP and TAP in the environment. IMPORTANCE Rising levels of antibiotic resistance are undermining ecological and human health as a result of the indiscriminate usage of antibiotics. Various resistance mechanisms have been characterized-for example, genes encoding proteins that degrade antibiotics-and yet, this requires further exploration. In this study, we report a novel gene encoding an oxidase involved in the inactivation of typical amphenicol antibiotics (chloramphenicol and thiamphenicol), and the molecular mechanism is elucidated. The findings provide novel data with which to understand the capabilities of bacteria to tackle antibiotic stress, as well as the complex function of enzymes in the contexts of antibiotic resistance development and antibiotic removal. The reported gene can be further employed as an indicator to monitor amphenicol's fate in the environment, thus benefiting risk assessment in this era of antibiotic resistance.
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Degani E, Prasad MVR, Paradkar A, Pena R, Soltangheisi A, Ullah I, Warr B, Tibbett M. A critical review of Pongamia pinnata multiple applications: From land remediation and carbon sequestration to socioeconomic benefits. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 324:116297. [PMID: 36174475 DOI: 10.1016/j.jenvman.2022.116297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 09/07/2022] [Accepted: 09/13/2022] [Indexed: 06/16/2023]
Abstract
Pongamia pinnata (L.) Pierre (Pongamia) is a tree native to Southeast Asia. Recently, interest in Pongamia focused on its potential as a biofuel source as its seeds contain around 40% oil. However, Pongamia has multiple applications beyond biofuel production. It is a legume, can form symbiotic associations with mycorrhizal fungi, has been shown to be tolerant to drought, salinity, and heavy metals in soil, and has potential to mitigate climate change. Additionally, Pongamia oil has medicinal properties, can be used as biopesticide, insect repellent, to produce soap, and as a source of edible grade vegetable oil. The seed cake can be used as a source of bioenergy, food and feed protein, and organic fertiliser, and the flowers are a good source of pollen and nectar. Pongamia can also bring socio-economic benefits as its ability to restore degraded and contaminated land provides opportunities for local communities through novel valorisation pathways. These multiple applications have potential to form part of a circular bioeconomy in line with sustainable development goals. Although research on the multiple applications of Pongamia has grown considerably, knowledge gaps remain and these need to be addressed so that the full potential of Pongamia can be achieved. Further understanding of the mechanisms underlying its resilience to abiotic stresses, phytoremediation potential and biotic interactions should be a priority, and co-ordinated breeding efforts will be key. Here, we critically review the available literature on Pongamia and highlight gaps in knowledge in which future research should focus on to ensure that the full potential of this versatile tree can be achieved. We conclude that Pongamia can potentially form part of a circular bioeconomy and that harnessing the multiple applications of Pongamia in a holistic manner, with collaboration among key stakeholders, is crucial for the successful application of its benefits far beyond biofuel production.
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Affiliation(s)
- Erika Degani
- Department of Sustainable Land Management & Soil Research Centre, School of Agriculture, Policy and Development, University of Reading, Reading, United Kingdom
| | | | - Anant Paradkar
- Centre for Pharmaceutical Engineering Science, School of Pharmacy and Medical Science, University of Bradford, Bradford, United Kingdom
| | - Rodica Pena
- Department of Sustainable Land Management & Soil Research Centre, School of Agriculture, Policy and Development, University of Reading, Reading, United Kingdom
| | - Amin Soltangheisi
- Department of Sustainable Land Management & Soil Research Centre, School of Agriculture, Policy and Development, University of Reading, Reading, United Kingdom
| | - Ihsan Ullah
- Department of Sustainable Land Management & Soil Research Centre, School of Agriculture, Policy and Development, University of Reading, Reading, United Kingdom
| | - Benjamin Warr
- Faculty of AgriSciences, Stellenbosch University, South Africa; PHYLA Earth Ltd., London, UK
| | - Mark Tibbett
- Department of Sustainable Land Management & Soil Research Centre, School of Agriculture, Policy and Development, University of Reading, Reading, United Kingdom; School of Biological Sciences, The University of Western Australia, Perth, Australia.
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Ramos AL, Aquino M, García G, Gaspar M, de la Cruz C, Saavedra-Flores A, Brom S, Cervantes-Rivera R, Galindo-Sánchez CE, Hernandez R, Puhar A, Lupas AN, Sepulveda E. RpuS/R Is a Novel Two-Component Signal Transduction System That Regulates the Expression of the Pyruvate Symporter MctP in Sinorhizobium fredii NGR234. Front Microbiol 2022; 13:871077. [PMID: 35572670 PMCID: PMC9100948 DOI: 10.3389/fmicb.2022.871077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 04/11/2022] [Indexed: 11/16/2022] Open
Abstract
The SLC5/STAC histidine kinases comprise a recently identified family of sensor proteins in two-component signal transduction systems (TCSTS), in which the signaling domain is fused to an SLC5 solute symporter domain through a STAC domain. Only two members of this family have been characterized experimentally, the CrbS/R system that regulates acetate utilization in Vibrio and Pseudomonas, and the CbrA/B system that regulates the utilization of histidine in Pseudomonas and glucose in Azotobacter. In an attempt to expand the characterized members of this family beyond the Gammaproteobacteria, we identified two putative TCSTS in the Alphaproteobacterium Sinorhizobium fredii NGR234 whose sensor histidine kinases belong to the SLC5/STAC family. Using reverse genetics, we were able to identify the first TCSTS as a CrbS/R homolog that is also needed for growth on acetate, while the second TCSTS, RpuS/R, is a novel system required for optimal growth on pyruvate. Using RNAseq and transcriptional fusions, we determined that in S. fredii the RpuS/R system upregulates the expression of an operon coding for the pyruvate symporter MctP when pyruvate is the sole carbon source. In addition, we identified a conserved DNA sequence motif in the putative promoter region of the mctP operon that is essential for the RpuR-mediated transcriptional activation of genes under pyruvate-utilizing conditions. Finally, we show that S. fredii mutants lacking these TCSTS are affected in nodulation, producing fewer nodules than the parent strain and at a slower rate.
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Affiliation(s)
| | - Maria Aquino
- Facultad de Ciencias, Universidad Autónoma de Baja California, Ensenada, Mexico
| | - Gema García
- Facultad de Biología, Universidad Autónoma de Sinaloa, Culiacan, Mexico
| | - Miriam Gaspar
- Facultad de Ciencias, Universidad Autónoma de Baja California, Ensenada, Mexico
| | - Cristina de la Cruz
- Programa de Ingeniería Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Anaid Saavedra-Flores
- Departamento de Biotecnología Marina, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Ensenada, Mexico
| | - Susana Brom
- Programa de Ingeniería Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Ramón Cervantes-Rivera
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
- Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Clara Elizabeth Galindo-Sánchez
- Departamento de Biotecnología Marina, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Ensenada, Mexico
| | - Rufina Hernandez
- Departamento de Microbiología, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Ensenada, Mexico
| | - Andrea Puhar
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
- Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Andrei N. Lupas
- Department of Protein Evolution, Max Planck Institute for Biology, Tübingen, Germany
| | - Edgardo Sepulveda
- CONACYT-Departamento de Microbiología, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Ensenada, Mexico
- *Correspondence: Edgardo Sepulveda,
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Teulet A, Camuel A, Perret X, Giraud E. The Versatile Roles of Type III Secretion Systems in Rhizobia-Legume Symbioses. Annu Rev Microbiol 2022; 76:45-65. [PMID: 35395168 DOI: 10.1146/annurev-micro-041020-032624] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
To suppress plant immunity and promote the intracellular infection required for fixing nitrogen for the benefit of their legume hosts, many rhizobia use type III secretion systems (T3SSs) that deliver effector proteins (T3Es) inside host cells. As reported for interactions between pathogens and host plants, the immune system of legume hosts and the cocktail of T3Es secreted by rhizobia determine the symbiotic outcome. If they remain undetected, T3Es may reduce plant immunity and thus promote infection of legumes by rhizobia. If one or more of the secreted T3Es are recognized by the cognate plant receptors, defense responses are triggered and rhizobial infection may abort. However, some rhizobial T3Es can also circumvent the need for nodulation (Nod) factors to trigger nodule formation. Here we review the multifaceted roles played by rhizobial T3Es during symbiotic interactions with legumes. Expected final online publication date for the Annual Review of Microbiology, Volume 76 is September 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Albin Teulet
- Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), IRD, Institut Agro, INRAE, Université de Montpellier, and CIRAD, Montpellier, France;
| | - Alicia Camuel
- Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), IRD, Institut Agro, INRAE, Université de Montpellier, and CIRAD, Montpellier, France; .,PHIM Plant Health Institute, IRD, Institut Agro, INRAE, Université de Montpellier, and CIRAD, Montpellier, France
| | - Xavier Perret
- Laboratory of Microbial Genetics, Department of Botany and Plant Biology, University of Geneva, Geneva, Switzerland
| | - Eric Giraud
- Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), IRD, Institut Agro, INRAE, Université de Montpellier, and CIRAD, Montpellier, France; .,PHIM Plant Health Institute, IRD, Institut Agro, INRAE, Université de Montpellier, and CIRAD, Montpellier, France
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Exploiting Rhizobium for Cadmium Sulphide Nanoparticle Synthesis: Heterologous Expression of an Escherichia coli DH10B Enzyme, YbdK [EC: 6.3.2.2] in Sinorhizobium fredii NGR234. JOURNAL OF PURE AND APPLIED MICROBIOLOGY 2022. [DOI: 10.22207/jpam.16.1.59] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Escherichia coli DH10B has 1.1 kb ybdK gene which is responsible for encoding YbdK enzyme that possess a Gamma glutamyl cysteine synthetase activity. ybdK gene was ligated downstream of a constitutive derepressed lac promoter of a low copy number plasmid vector pBBR1MCS-2, giving rise to a recombinant plasmid pPAT. Sinorhizobium fredii NGR234 transformed with pPAT showed an augmented production of glutathione which in turn increased the production of cadmium sulphide nanoparticles to some extent. Also, a heterologous expression of YbdK in Sinorhizobium fredii NGR234 improved the oxidation status of bacterial cells which is confirmed by fluorescence microscopy images and fluorometry. Genetically modified (GM) cells stained by DCFDA showed a significant decrease in fluorescence compared to wild type (WT) cells. Physical and chemical properties of the nanoparticles produced by the pPAT transformed Sinorhizobium fredii NGR234 differed significantly compared to wild type (WT) Sinorhizobium fredii NGR234. Comparative analysis of the nanoparticles by FTIR and SEM analysis revealed the functional groups attached to nanoparticles and average nanoparticle size respectively. Nanoparticles synthesized by genetically modified (GM) bacteria were about 3 times smaller in size compared to those produced by wild type (WT) rhizobium. FTIR analysis revealed an augmented presence of peptide with the nanoparticles produced by GM bacteria compared to those produced by the WT bacteria. XRD data revealed that biosynthesized CdS nanoparticles are face centered crystalline particles which was confirmed by comparing the peaks to standard JCPDS data (JCPDS card no. 10-454).
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Zboralski A, Biessy A, Filion M. Bridging the Gap: Type III Secretion Systems in Plant-Beneficial Bacteria. Microorganisms 2022; 10:187. [PMID: 35056636 PMCID: PMC8780523 DOI: 10.3390/microorganisms10010187] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/10/2022] [Accepted: 01/12/2022] [Indexed: 12/30/2022] Open
Abstract
Type III secretion systems (T3SSs) are bacterial membrane-embedded nanomachines translocating effector proteins into the cytoplasm of eukaryotic cells. They have been intensively studied for their important roles in animal and plant bacterial diseases. Over the past two decades, genome sequencing has unveiled their ubiquitous distribution in many taxa of Gram-negative bacteria, including plant-beneficial ones. Here, we discuss the distribution and functions of the T3SS in two agronomically important bacterial groups: the symbiotic nodule-forming nitrogen-fixing rhizobia and the free-living plant-beneficial Pseudomonas spp. In legume-rhizobia symbiosis, T3SSs and their cognate effectors play important roles, including the modulation of the plant immune response and the initiation of the nodulation process in some cases. In plant-beneficial Pseudomonas spp., the roles of T3SSs are not fully understood, but pertain to plant immunity suppression, biocontrol against eukaryotic plant pathogens, mycorrhization facilitation, and possibly resistance against protist predation. The diversity of T3SSs in plant-beneficial bacteria points to their important roles in multifarious interkingdom interactions in the rhizosphere. We argue that the gap in research on T3SSs in plant-beneficial bacteria must be bridged to better understand bacteria/eukaryotes rhizosphere interactions and to support the development of efficient plant-growth promoting microbial inoculants.
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Affiliation(s)
| | | | - Martin Filion
- Research and Development Centre, Agriculture and Agri-Food Canada, 430 Gouin Boulevard, Saint-Jean-sur-Richelieu, QC J3B 3E6, Canada; (A.Z.); (A.B.)
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Rosselli R, La Porta N, Muresu R, Stevanato P, Concheri G, Squartini A. Pangenomics of the Symbiotic Rhizobiales. Core and Accessory Functions Across a Group Endowed with High Levels of Genomic Plasticity. Microorganisms 2021; 9:microorganisms9020407. [PMID: 33669391 PMCID: PMC7920277 DOI: 10.3390/microorganisms9020407] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 02/10/2021] [Accepted: 02/11/2021] [Indexed: 11/16/2022] Open
Abstract
Pangenome analyses reveal major clues on evolutionary instances and critical genome core conservation. The order Rhizobiales encompasses several families with rather disparate ecological attitudes. Among them, Rhizobiaceae, Bradyrhizobiaceae, Phyllobacteriacreae and Xanthobacteriaceae, include members proficient in mutualistic symbioses with plants based on the bacterial conversion of N2 into ammonia (nitrogen-fixation). The pangenome of 12 nitrogen-fixing plant symbionts of the Rhizobiales was analyzed yielding total 37,364 loci, with a core genome constituting 700 genes. The percentage of core genes averaged 10.2% over single genomes, and between 5% to 7% were found to be plasmid-associated. The comparison between a representative reference genome and the core genome subset, showed the core genome highly enriched in genes for macromolecule metabolism, ribosomal constituents and overall translation machinery, while membrane/periplasm-associated genes, and transport domains resulted under-represented. The analysis of protein functions revealed that between 1.7% and 4.9% of core proteins could putatively have different functions.
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Affiliation(s)
- Riccardo Rosselli
- Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute of Sea Research, NL-1790 AB Den Burg, The Netherlands;
- Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, 03690 Alicante, Spain
| | - Nicola La Porta
- Department of Sustainable Agrobiosystems and Bioresources, Research and Innovation Centre, Fondazione Edmund Mach, 38098 San Michele all’Adige, Italy;
- MOUNTFOR Project Centre, European Forest Institute, 38098 San Michele all’Adige, Italy
| | - Rosella Muresu
- Institute of Animal Production Systems in Mediterranean Environments-National Research Council, 07040 Sassari, Italy;
| | - Piergiorgio Stevanato
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova, 35020 Legnaro, Italy; (P.S.); (G.C.)
| | - Giuseppe Concheri
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova, 35020 Legnaro, Italy; (P.S.); (G.C.)
| | - Andrea Squartini
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova, 35020 Legnaro, Italy; (P.S.); (G.C.)
- Correspondence: ; Tel.: +39-049-8272-923
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11
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Fine-Scale Patterns of Genetic Structure in the Host Plant Chamaecrista fasciculata (Fabaceae) and Its Nodulating Rhizobia Symbionts. PLANTS 2020; 9:plants9121719. [PMID: 33297297 PMCID: PMC7762326 DOI: 10.3390/plants9121719] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 11/30/2020] [Accepted: 12/03/2020] [Indexed: 01/04/2023]
Abstract
In natural plant populations, a fine-scale spatial genetic structure (SGS) can result from limited gene flow, selection pressures or spatial autocorrelation. However, limited gene flow is considered the predominant determinant in the establishment of SGS. With limited dispersal ability of bacterial cells in soil and host influence on their variety and abundance, spatial autocorrelation of bacterial communities associated with plants is expected. For this study, we collected genetic data from legume host plants, Chamaecrista fasciculata, their Bradyrhizobium symbionts and rhizosphere free-living bacteria at a small spatial scale to evaluate the extent to which symbiotic partners will have similar SGS and to understand how plant hosts choose among nodulating symbionts. We found SGS across all sampled plants for both the host plants and nodulating rhizobia, suggesting that both organisms are influenced by similar mechanisms structuring genetic diversity or shared habitat preferences by both plants and microbes. We also found that plant genetic identity and geographic distance might serve as predictors of nodulating rhizobia genetic identity. Bradyrhizobium elkanii was the only type of rhizobia found in nodules, which suggests some level of selection by the host plant.
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Cao Y, Jiang G, Li M, Fang X, Zhu D, Qiu W, Zhu J, Yu D, Xu Y, Zhong Z, Zhu J. Glutaredoxins Play an Important Role in the Redox Homeostasis and Symbiotic Capacity of Azorhizobium caulinodans ORS571. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2020; 33:1381-1393. [PMID: 32970520 DOI: 10.1094/mpmi-04-20-0098-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Glutaredoxin (GRX) plays an essential role in the control of the cellular redox state and related pathways in many organisms. There is limited information on GRXs from the model nitrogen (N2)-fixing bacterium Azorhizobium caulinodans. In the present work, we identified and performed functional analyses of monothiol and dithiol GRXs in A. caulinodans in the free-living state and during symbiosis with Sesbania rostrata. Our data show that monothiol GRXs may be very important for bacterial growth under normal conditions and in response to oxidative stress due to imbalance of the redox state in grx mutants of A. caulinodans. Functional redundancies were also observed within monothiol and dithiol GRXs in terms of different physiological functions. The changes in catalase activity and iron content in grx mutants were assumed to favor the maintenance of bacterial resistance against oxidants, nodulation, and N2 fixation efficiency in this bacterium. Furthermore, the monothiol GRX12 and dithiol GRX34 play a collective role in symbiotic associations between A. caulinodans and Sesbania rostrata. Our study provided systematic evidence that further investigations are required to understand the importance of glutaredoxins in A. caulinodans and other rhizobia.
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Affiliation(s)
- Yajun Cao
- Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, PR China
| | - Gaofei Jiang
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, National Engineering Research Center for Organic-based Fertilizers, Postdoctoral Station of Agricultural Resources and Environment, Nanjing Agricultural University, 210095 Nanjing, PR China
| | - Mingxu Li
- Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, PR China
| | - Xingxing Fang
- Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, PR China
| | - Dan Zhu
- Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, PR China
| | - Wei Qiu
- Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, PR China
| | - Juanjuan Zhu
- Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, PR China
| | - Daogeng Yu
- Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Science, 571737 Danzhou, Hainan, PR China
| | - Yangchun Xu
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, National Engineering Research Center for Organic-based Fertilizers, Postdoctoral Station of Agricultural Resources and Environment, Nanjing Agricultural University, 210095 Nanjing, PR China
| | - Zengtao Zhong
- Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, PR China
| | - Jun Zhu
- Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, PR China
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Bamba M, Aoki S, Kajita T, Setoguchi H, Watano Y, Sato S, Tsuchimatsu T. Massive rhizobial genomic variation associated with partner quality in Lotus-Mesorhizobium symbiosis. FEMS Microbiol Ecol 2020; 96:5917975. [PMID: 33016310 DOI: 10.1093/femsec/fiaa202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 09/29/2020] [Indexed: 11/14/2022] Open
Abstract
Variation in partner quality is commonly observed in diverse cooperative relationships, despite the theoretical prediction that selection favoring high-quality partners should eliminate such variation. Here, we investigated how genetic variation in partner quality could be maintained in the nitrogen-fixing mutualism between Lotus japonicus and Mesorhizobium bacteria. We reconstructed de novo assembled full-genome sequences from nine rhizobial symbionts, finding massive variation in the core genome and the similar symbiotic islands, indicating recent horizontal gene transfer (HGT) of the symbiosis islands into diverse Mesorhizobium lineages. A cross-inoculation experiment using 9 sequenced rhizobial symbionts and 15 L. japonicus accessions revealed extensive quality variation represented by plant growth phenotypes, including genotype-by-genotype interactions. Variation in quality was not associated with the presence/absence variation in known symbiosis-related genes in the symbiosis island; rather, it showed significant correlation with the core genome variation. Given the recurrent HGT of the symbiosis islands into diverse Mesorhizobium strains, local Mesorhizobium communities could serve as a major source of variation for core genomes, which might prevent variation in partner quality from fixing, even in the presence of selection favoring high-quality partners. These findings highlight the novel role of HGT of symbiosis islands in maintaining partner quality variation in the legume-rhizobia symbiosis.
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Affiliation(s)
- Masaru Bamba
- Department of Biology (Frontier Science Program), Graduate School of Science and Engineering, Chiba University, 1-33 Yayoi, Inage, Chiba 263-8522, Japan.,Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba, Sendai 980-8577, Japan
| | - Seishiro Aoki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Tadashi Kajita
- Iriomote Station, Tropical Biosphere Research Center, The University of the Ryukyus, 870 Uehara, Taketomi-cho, Yaeyama-gun, Okinawa 907-1541, Japan
| | - Hiroaki Setoguchi
- Graduate School of Human and Environmental Studies, Kyoto University, Yoshida-nihonmatsu-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Yasuyuki Watano
- Department of Biology, Graduate School of Science, Chiba University, 1-33 Yayoi, Inage, Chiba 263-8522, Japan
| | - Shusei Sato
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba, Sendai 980-8577, Japan
| | - Takashi Tsuchimatsu
- Department of Biology, Graduate School of Science, Chiba University, 1-33 Yayoi, Inage, Chiba 263-8522, Japan.,Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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14
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Yang LL, Jiang Z, Li Y, Wang ET, Zhi XY. Plasmids Related to the Symbiotic Nitrogen Fixation Are Not Only Cooperated Functionally but Also May Have Evolved over a Time Span in Family Rhizobiaceae. Genome Biol Evol 2020; 12:2002-2014. [PMID: 32687170 PMCID: PMC7719263 DOI: 10.1093/gbe/evaa152] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/15/2020] [Indexed: 12/17/2022] Open
Abstract
Rhizobia are soil bacteria capable of forming symbiotic nitrogen-fixing nodules associated with leguminous plants. In fast-growing legume-nodulating rhizobia, such as the species in the family Rhizobiaceae, the symbiotic plasmid is the main genetic basis for nitrogen-fixing symbiosis, and is susceptible to horizontal gene transfer. To further understand the symbioses evolution in Rhizobiaceae, we analyzed the pan-genome of this family based on 92 genomes of type/reference strains and reconstructed its phylogeny using a phylogenomics approach. Intriguingly, although the genetic expansion that occurred in chromosomal regions was the main reason for the high proportion of low-frequency flexible gene families in the pan-genome, gene gain events associated with accessory plasmids introduced more genes into the genomes of nitrogen-fixing species. For symbiotic plasmids, although horizontal gene transfer frequently occurred, transfer may be impeded by, such as, the host’s physical isolation and soil conditions, even among phylogenetically close species. During coevolution with leguminous hosts, the plasmid system, including accessory and symbiotic plasmids, may have evolved over a time span, and provided rhizobial species with the ability to adapt to various environmental conditions and helped them achieve nitrogen fixation. These findings provide new insights into the phylogeny of Rhizobiaceae and advance our understanding of the evolution of symbiotic nitrogen fixation.
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Affiliation(s)
- Ling-Ling Yang
- Yunnan Institute of Microbiology, School of Life Sciences, Yunnan University, Kunming, Yunnan, PR China
| | - Zhao Jiang
- Yunnan Institute of Microbiology, School of Life Sciences, Yunnan University, Kunming, Yunnan, PR China
| | - Yan Li
- Key Laboratory of Coastal Biology and Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong, PR China
| | - En-Tao Wang
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City D.F., México
| | - Xiao-Yang Zhi
- Yunnan Institute of Microbiology, School of Life Sciences, Yunnan University, Kunming, Yunnan, PR China
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Ardissone S, Kint N, Viollier PH. Specificity in glycosylation of multiple flagellins by the modular and cell cycle regulated glycosyltransferase FlmG. eLife 2020; 9:e60488. [PMID: 33108275 PMCID: PMC7591256 DOI: 10.7554/elife.60488] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Accepted: 09/24/2020] [Indexed: 12/12/2022] Open
Abstract
How specificity is programmed into post-translational modification of proteins by glycosylation is poorly understood, especially for O-linked glycosylation systems. Here we reconstitute and dissect the substrate specificity underpinning the cytoplasmic O-glycosylation pathway that modifies all six flagellins, five structural and one regulatory paralog, in Caulobacter crescentus, a monopolarly flagellated alpha-proteobacterium. We characterize the biosynthetic pathway for the sialic acid-like sugar pseudaminic acid and show its requirement for flagellation, flagellin modification and efficient export. The cognate NeuB enzyme that condenses phosphoenolpyruvate with a hexose into pseudaminic acid is functionally interchangeable with other pseudaminic acid synthases. The previously unknown and cell cycle-regulated FlmG protein, a defining member of a new class of cytoplasmic O-glycosyltransferases, is required and sufficient for flagellin modification. The substrate specificity of FlmG is conferred by its N-terminal flagellin-binding domain. FlmG accumulates before the FlaF secretion chaperone, potentially timing flagellin modification, export, and assembly during the cell division cycle.
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Affiliation(s)
- Silvia Ardissone
- Department of Microbiology & Molecular Medicine, Faculty of Medicine / CMU, University of GenevaGenèveSwitzerland
| | - Nicolas Kint
- Department of Microbiology & Molecular Medicine, Faculty of Medicine / CMU, University of GenevaGenèveSwitzerland
| | - Patrick H Viollier
- Department of Microbiology & Molecular Medicine, Faculty of Medicine / CMU, University of GenevaGenèveSwitzerland
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16
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All living cells are cognitive. Biochem Biophys Res Commun 2020; 564:134-149. [PMID: 32972747 DOI: 10.1016/j.bbrc.2020.08.120] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 07/28/2020] [Accepted: 08/19/2020] [Indexed: 12/24/2022]
Abstract
All living cells sense and respond to changes in external or internal conditions. Without that cognitive capacity, they could not obtain nutrition essential for growth, survive inevitable ecological changes, or correct accidents in the complex processes of reproduction. Wherever examined, even the smallest living cells (prokaryotes) display sophisticated regulatory networks establishing appropriate adaptations to stress conditions that maximize the probability of survival. Supposedly "simple" prokaryotic organisms also display remarkable capabilities for intercellular signalling and multicellular coordination. These observations indicate that all living cells are cognitive.
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Teulet A, Gully D, Rouy Z, Camuel A, Koebnik R, Giraud E, Lassalle F. Phylogenetic distribution and evolutionary dynamics of nod and T3SS genes in the genus Bradyrhizobium. Microb Genom 2020; 6:mgen000407. [PMID: 32783800 PMCID: PMC7643967 DOI: 10.1099/mgen.0.000407] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 06/26/2020] [Indexed: 01/22/2023] Open
Abstract
Bradyrhizobium are abundant soil bacteria and the major symbiont of legumes. The recent availability of Bradyrhizobium genome sequences provides a large source of information for analysis of symbiotic traits. In this study, we investigated the evolutionary dynamics of the nodulation genes (nod) and their relationship with the genes encoding type III secretion systems (T3SS) and their effectors among bradyrhizobia. Based on the comparative analysis of 146 Bradyrhizobium genome sequences, we identified six different types of T3SS gene clusters. The two predominant cluster types are designated RhcIa and RhcIb and both belong to the RhcI-T3SS family previously described in other rhizobia. They are found in 92/146 strains, most of them also containing nod genes. RhcIa and RhcIb gene clusters differ in the genes they carry: while the translocon-encoding gene nopX is systematically found in strains containing RhcIb, the nopE and nopH genes are specifically conserved in strains containing RhcIa, suggesting that these last two genes might functionally substitute nopX and play a role related to effector translocation. Phylogenetic analysis suggests that bradyrhizobia simultaneously gained nod and RhcI-T3SS gene clusters via horizontal transfer or subsequent vertical inheritance of a symbiotic island containing both. Sequence similarity searches for known Nop effector proteins in bradyrhizobial proteomes revealed the absence of a so-called core effectome, i.e. that no effector is conserved among all Bradyrhizobium strains. However, NopM and SUMO proteases were found to be the main effector families, being represented in the majority of the genus. This study indicates that bradyrhizobial T3SSs might play a more significant symbiotic role than previously thought and provides new candidates among T3SS structural proteins and effectors for future functional investigations.
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Affiliation(s)
- Albin Teulet
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/SupAgro/INRA/Université de Montpellier/CIRAD, TA-A82/J – Campus de Baillarguet 34398, Montpellier cedex 5, France
| | - Djamel Gully
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/SupAgro/INRA/Université de Montpellier/CIRAD, TA-A82/J – Campus de Baillarguet 34398, Montpellier cedex 5, France
| | - Zoe Rouy
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, Université d’Évry, Université Paris-Saclay, CNRS, Evry, France
| | - Alicia Camuel
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/SupAgro/INRA/Université de Montpellier/CIRAD, TA-A82/J – Campus de Baillarguet 34398, Montpellier cedex 5, France
| | - Ralf Koebnik
- IRD, CIRAD, Université de Montpellier, IPME, Montpellier, France
| | - Eric Giraud
- IRD, Laboratoire des Symbioses Tropicales et Méditerranéennes (LSTM), UMR IRD/SupAgro/INRA/Université de Montpellier/CIRAD, TA-A82/J – Campus de Baillarguet 34398, Montpellier cedex 5, France
| | - Florent Lassalle
- Department of Infectious Disease Epidemiology. Imperial College London, St Mary’s Hospital Campus, Praed Street, London W2 1NY, UK
- Pathogen and Microbes Program, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SA, UK
- Present address: Pathogen and Microbes Program, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SA, UK
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Unay J, Perret X. A Minimal Genetic Passkey to Unlock Many Legume Doors to Root Nodulation by Rhizobia. Genes (Basel) 2020; 11:genes11050521. [PMID: 32392829 PMCID: PMC7290934 DOI: 10.3390/genes11050521] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 04/30/2020] [Accepted: 05/04/2020] [Indexed: 12/31/2022] Open
Abstract
In legume crops, formation of developmentally mature nodules is a prerequisite for efficient nitrogen fixation by populations of rhizobial bacteroids established inside nodule cells. Development of root nodules, and concomitant microbial colonization of plant cells, are constrained by sets of recognition signals exchanged by infecting rhizobia and their legume hosts, with much of the specificity of symbiotic interactions being determined by the flavonoid cocktails released by legume roots and the strain-specific nodulation factors (NFs) secreted by rhizobia. Hence, much of Sinorhizobium fredii strain NGR234 symbiotic promiscuity was thought to stem from a family of >80 structurally diverse NFs and associated nodulation keys in the form of secreted effector proteins and rhamnose-rich surface polysaccharides. Here, we show instead that a mini-symbiotic plasmid (pMiniSym2) carrying only the nodABCIJ, nodS and nodD1 genes of NGR234 conferred promiscuous nodulation to ANU265, a derivative strain cured of the large symbiotic plasmid pNGR234a. The ANU265::pMiniSym2 transconjugant triggered nodulation responses on 12 of the 22 legumes we tested. On roots of Macroptilium atropurpureum, Leucaena leucocephala and Vigna unguiculata, ANU265::pMiniSym2 formed mature-like nodule and successfully infected nodule cells. While cowpea and siratro responded to nodule colonization with defense responses that eventually eliminated bacteria, L. leucocephala formed leghemoglobin-containing mature-like nodules inside which the pMiniSym2 transconjugant established persistent intracellular colonies. These data show seven nodulation genes of NGR234 suffice to trigger nodule formation on roots of many hosts and to establish chronic infections in Leucaena cells.
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Lomovatskaya LA, Romanenko AS. Secretion Systems of Bacterial Phytopathogens and Mutualists (Review). APPL BIOCHEM MICRO+ 2020. [DOI: 10.1134/s0003683820020106] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Deciphering the Symbiotic Significance of Quorum Sensing Systems of Sinorhizobium fredii HH103. Microorganisms 2020; 8:microorganisms8010068. [PMID: 31906451 PMCID: PMC7022240 DOI: 10.3390/microorganisms8010068] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 12/26/2019] [Accepted: 12/31/2019] [Indexed: 01/21/2023] Open
Abstract
Quorum sensing (QS) is a bacterial cell-to-cell signaling mechanism that collectively regulates and synchronizes behaviors by means of small diffusible chemical molecules. In rhizobia, QS systems usually relies on the synthesis and detection of N-acyl-homoserine lactones (AHLs). In the model bacterium Sinorhizobium meliloti functions regulated by the QS systems TraI-TraR and SinI-SinR(-ExpR) include plasmid transfer, production of surface polysaccharides, motility, growth rate and nodulation. These systems are also present in other bacteria of the Sinorhizobium genus, with variations at the species and strain level. In Sinorhizobium fredii NGR234 phenotypes regulated by QS are plasmid transfer, growth rate, sedimentation, motility, biofilm formation, EPS production and copy number of the symbiotic plasmid (pSym). The analysis of the S. fredii HH103 genomes reveal also the presence of both QS systems. In this manuscript we characterized the QS systems of S. fredii HH103, determining that both TraI and SinI AHL-synthases proteins are responsible of the production of short- and long-chain AHLs, respectively, at very low and not physiological concentrations. Interestingly, the main HH103 luxR-type genes, expR and traR, are split into two ORFs, suggesting that in S. fredii HH103 the corresponding carboxy-terminal proteins, which contain the DNA-binding motives, may control target genes in an AHL-independent manner. The presence of a split traR gene is common in other S. fredii strains.
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Lucke M, Correa MG, Levy A. The Role of Secretion Systems, Effectors, and Secondary Metabolites of Beneficial Rhizobacteria in Interactions With Plants and Microbes. FRONTIERS IN PLANT SCIENCE 2020; 11:589416. [PMID: 33240304 PMCID: PMC7680756 DOI: 10.3389/fpls.2020.589416] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 10/14/2020] [Indexed: 05/05/2023]
Abstract
Beneficial rhizobacteria dwell in plant roots and promote plant growth, development, and resistance to various stress types. In recent years there have been large-scale efforts to culture root-associated bacteria and sequence their genomes to uncover novel beneficial microbes. However, only a few strains of rhizobacteria from the large pool of soil microbes have been studied at the molecular level. This review focuses on the molecular basis underlying the phenotypes of three beneficial microbe groups; (1) plant-growth promoting rhizobacteria (PGPR), (2) root nodulating bacteria (RNB), and (3) biocontrol agents (BCAs). We focus on bacterial proteins and secondary metabolites that mediate known phenotypes within and around plants, and the mechanisms used to secrete these. We highlight the necessity for a better understanding of bacterial genes responsible for beneficial plant traits, which can be used for targeted gene-centered and molecule-centered discovery and deployment of novel beneficial rhizobacteria.
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Rehman HM, Cheung WL, Wong KS, Xie M, Luk CY, Wong FL, Li MW, Tsai SN, To WT, Chan LY, Lam HM. High-Throughput Mass Spectrometric Analysis of the Whole Proteome and Secretome From Sinorhizobium fredii Strains CCBAU25509 and CCBAU45436. Front Microbiol 2019; 10:2569. [PMID: 31798547 PMCID: PMC6865838 DOI: 10.3389/fmicb.2019.02569] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 10/23/2019] [Indexed: 01/11/2023] Open
Abstract
Sinorhizobium fredii is a dominant rhizobium on alkaline-saline land that can induce nitrogen-fixing symbiotic root nodules in soybean. Two S. fredii strains, CCBAU25509 and CCBAU45436, were used in this study to facilitate in-depth analyses of this species and its interactions with soybean. We have previously completed the full assembly of the genomes and detailed transcriptomic analyses for these two S. fredii strains, CCBAU25509 and CCBAU45436, that exhibit differential compatibility toward some soybean hosts. In this work, we performed high-throughput Orbitrap analyses of the whole proteomes and secretomes of CCBAU25509 and CCBAU45436 at different growth stages. Our proteomic data cover coding sequences in the chromosome, chromid, symbiotic plasmid, and other accessory plasmids. In general, we found higher levels of protein expression by genes in the chromosomal genome, whereas proteins encoded by the symbiotic plasmid were differentially accumulated in bacteroids. We identified secreted proteins from the extracellular medium, including seven and eight Nodulation Outer Proteins (Nops) encoded by the symbiotic plasmid of CCBAU25509 and CCBAU45436, respectively. Differential host restriction of CCBAU25509 and CCBAU45436 is regulated by the allelic type of the soybean Rj2(Rfg1) protein. Using sequencing data from this work and available in public databases, our analysis confirmed that the soybean Rj2(Rfg1) protein has three major allelic types (Rj2/rfg1, rj2/Rfg1, rj2/rfg1) that determine the host restriction of some Bradyrhizobium diazoefficiens and S. fredii strains. A mutant defective in the type 3 protein secretion system (T3SS) in CCBAU25509 allowed this strain to nodulate otherwise-incompatible soybeans carrying the rj2/Rfg1 allelic type, probably by disrupting Nops secretion. The allelic forms of NopP and NopI in S. fredii might be associated with the restriction imposed by Rfg1. By swapping the NopP between CCBAU25509 and CCBAU45436, we found that only the strains carrying NopP from CCBAU45436 could nodulate soybeans carrying the rj2/Rfg1 allelic type. However, no direct interaction between either forms of NopP and Rfg1 could be observed.
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Affiliation(s)
- Hafiz Mamoon Rehman
- Center for Soybean Research of the State Key Laboratory of Agrobiotechnology and School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Wai-Lun Cheung
- Center for Soybean Research of the State Key Laboratory of Agrobiotechnology and School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Kwong-Sen Wong
- Center for Soybean Research of the State Key Laboratory of Agrobiotechnology and School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Min Xie
- Center for Soybean Research of the State Key Laboratory of Agrobiotechnology and School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Ching-Yee Luk
- Center for Soybean Research of the State Key Laboratory of Agrobiotechnology and School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Fuk-Ling Wong
- Center for Soybean Research of the State Key Laboratory of Agrobiotechnology and School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Man-Wah Li
- Center for Soybean Research of the State Key Laboratory of Agrobiotechnology and School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Sau-Na Tsai
- Center for Soybean Research of the State Key Laboratory of Agrobiotechnology and School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Wing-Ting To
- Center for Soybean Research of the State Key Laboratory of Agrobiotechnology and School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Lok-Yi Chan
- Center for Soybean Research of the State Key Laboratory of Agrobiotechnology and School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Hon-Ming Lam
- Center for Soybean Research of the State Key Laboratory of Agrobiotechnology and School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
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Cervantes L, Miranda-Sánchez F, Torres Tejerizo G, Romero D, Brom S. Plasmid pSfr64a and the symbiotic plasmid pSfr64b of Sinorhizobium fredii GR64 control each other's conjugative transfer through quorum-sensing elements. Plasmid 2019; 106:102443. [PMID: 31689451 DOI: 10.1016/j.plasmid.2019.102443] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 08/29/2019] [Accepted: 09/17/2019] [Indexed: 11/27/2022]
Abstract
Rhizobia are nitrogen-fixing symbionts of plants. Their genomes frequently contain large plasmids, some of which are able to perform conjugative transfer. Plasmid pSfr64a from Sinorhizobium fredii GR64 is a conjugative plasmid, whose transfer is regulated by quorum sensing genes encoded by itself (traR64a, traI64a), in the symbiotic plasmid pSfr64b (traR64b, traI64b), and in the chromosome (ngrI). Also, transfer of pSfr64b requires quorum sensing elements encoded in this plasmid (traR64b, traI64b), in pSfr64a (traR64a), and in the chromosome (ngrI). These results demonstrate that pSfr64a and the symbiotic plasmid depend on each other for conjugative transfer. Plasmid pSfr64a from S. fredii GR64 is unable to transfer from the genomic background of Rhizobium etli CFN42. Our results show that the relaxase of pRet42a is able to process the oriT of pSfr64a, and viceversa, underlining their functional similarity and suggesting that in addition to the external signals, the "cytoplasmic environment" may pose a barrier to plasmid dissemination, even if the plasmids are functional in other aspects.
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Affiliation(s)
- Laura Cervantes
- Programa de Ingeniería Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Fabiola Miranda-Sánchez
- Programa de Ingeniería Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico; Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Gonzalo Torres Tejerizo
- Programa de Ingeniería Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico; Instituto de Biotecnología y Biología Molecular (IBBM) - CCT-CONICET-La Plata, Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina
| | - David Romero
- Programa de Ingeniería Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Susana Brom
- Programa de Ingeniería Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico.
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24
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Wang X, Huo H, Luo Y, Liu D, Zhao L, Zong L, Chou M, Chen J, Wei G. Type III secretion systems impact Mesorhizobium amorphae CCNWGS0123 compatibility with Robinia pseudoacacia. TREE PHYSIOLOGY 2019; 39:1533-1550. [PMID: 31274160 DOI: 10.1093/treephys/tpz077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 06/26/2018] [Accepted: 06/18/2019] [Indexed: 06/09/2023]
Abstract
Rhizobia and legume plants are famous mutualistic symbiosis partners who provide nitrogen nutrition to the natural environment. Rhizobial type III secretion systems (T3SSs) deliver effectors that manipulate the metabolism of eukaryotic host cells. Mesorhizobium amorphae CCNWGS0123 (GS0123) contains two T3SS gene clusters, T3SS-I and T3SS-II. T3SS-I contains all the basal components for an integrated T3SS, and the expression of T3SS-I genes is up-regulated in the presence of flavonoids. In contrast, T3SS-II lacks the primary extracellular elements of T3SSs, and the expression of T3SS-II genes is down-regulated in the presence of flavonoids. Inoculation tests on Robinia pseudoacacia displayed considerable differences in gene expression patterns and levels among roots inoculated with GS0123 and T3SS-deficient mutant (GS0123ΔrhcN1 (GS0123ΔT1), GS0123ΔrhcN2 (GS0123ΔT2) and GS0123ΔrhcN1ΔrhcN2 (GS0123ΔS)). Compared with the GS0123-inoculated plants, GS0123ΔT1-inoculated roots formed very few infection threads and effective nodules, while GS0123ΔT2-inoculated roots formed a little fewer infection threads and effective nodules with increased numbers of bacteroids enclosed in one symbiosome. Moreover, almost no infection threads or effective nodules were observed in GS0123ΔS-inoculated roots. In addition to evaluations of plant immunity signals, we observed that the coexistence of T3SS-I and T3SS-II promoted infection by suppressing host defense response in the reactive oxygen species defense response pathway. Future studies should focus on identifying rhizobial T3SS effectors and their host target proteins.
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Affiliation(s)
- Xinye Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Science, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Haibo Huo
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Science, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Yantao Luo
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Science, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Dongying Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Science, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Liang Zhao
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Science, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Le Zong
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Science, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Minxia Chou
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Science, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Juan Chen
- State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Gehong Wei
- State Key Laboratory of Crop Stress Biology for Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Science, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
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25
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Dang X, Xie Z, Liu W, Sun Y, Liu X, Zhu Y, Staehelin C. The genome of Ensifer alkalisoli YIC4027 provides insights for host specificity and environmental adaptations. BMC Genomics 2019; 20:643. [PMID: 31405380 PMCID: PMC6689892 DOI: 10.1186/s12864-019-6004-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 07/29/2019] [Indexed: 12/21/2022] Open
Abstract
Background Ensifer alkalisoli YIC4027, a recently characterized nitrogen-fixing bacterium of the genus Ensifer, has been isolated from root nodules of the host plant Sesbania cannabina. This plant is widely used as green manure and for soil remediation. E. alkalisoli YIC4027 can grow in saline-alkaline soils and is a narrow-host-range strain that establishes a symbiotic relationship with S. cannabina. The complete genome of this strain was sequenced to better understand the genetic basis of host specificity and adaptation to saline-alkaline soils. Results E. alkalisoli YIC4027 was found to possess a 6.1-Mb genome consisting of three circular replicons: one chromosome (3.7 Mb), a chromid (1.9 Mb) and a plasmid (0.46 Mb). Genome comparisons showed that strain YIC4027 is phylogenetically related to broad-host-range Ensifer fredii strains. Synteny analysis revealed a strong collinearity between chromosomes of E. alkalisoli YIC4027 and those of the E. fredii NGR234 (3.9 Mb), HH103 (4.3 Mb) and USDA257 (6.48 Mb) strains. Notable differences were found for genes required for biosynthesis of nodulation factors and protein secretion systems, suggesting a role of these genes in host-specific nodulation. In addition, the genome analysis led to the identification of YIC4027 genes that are presumably related to adaptation to saline-alkaline soils, rhizosphere colonization and nodulation competitiveness. Analysis of chemotaxis cluster genes and nodulation tests with constructed che gene mutants indicated a role of chemotaxis and flagella-mediated motility in the symbiotic association between YIC4027 and S. cannabina. Conclusions This study provides a basis for a better understanding of host specific nodulation and of adaptation to a saline-alkaline rhizosphere. This information offers the perspective to prepare optimal E. alkalisoli inocula for agriculture use and soil remediation. Electronic supplementary material The online version of this article (10.1186/s12864-019-6004-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xiaoxiao Dang
- Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China.,University of Chinese Academy of Sciences, Beijing, China.,Center for Ocean Mag-Science, Chinese Academy of Sciences, Qingdao, People's Republic of China
| | - Zhihong Xie
- Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China. .,Center for Ocean Mag-Science, Chinese Academy of Sciences, Qingdao, People's Republic of China.
| | - Wei Liu
- Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China.,Center for Ocean Mag-Science, Chinese Academy of Sciences, Qingdao, People's Republic of China
| | - Yu Sun
- Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China.,University of Chinese Academy of Sciences, Beijing, China.,Center for Ocean Mag-Science, Chinese Academy of Sciences, Qingdao, People's Republic of China
| | - Xiaolin Liu
- Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China.,University of Chinese Academy of Sciences, Beijing, China.,Center for Ocean Mag-Science, Chinese Academy of Sciences, Qingdao, People's Republic of China
| | - Yongqiang Zhu
- Shanghai-MOST Key Laboratory of Health and Disease Genomics, Chinese National Human Genome Center at Shanghai, Shanghai, 201203, China
| | - Christian Staehelin
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China
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26
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Phan VTH, Bernier-Latmani R, Tisserand D, Bardelli F, Le Pape P, Frutschi M, Gehin A, Couture RM, Charlet L. As release under the microbial sulfate reduction during redox oscillations in the upper Mekong delta aquifers, Vietnam: A mechanistic study. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 663:718-730. [PMID: 30731417 DOI: 10.1016/j.scitotenv.2019.01.219] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 12/14/2018] [Accepted: 01/18/2019] [Indexed: 06/09/2023]
Abstract
The impact of seasonal fluctuations linked to monsoon and irrigation generates redox oscillations in the subsurface, influencing the release of arsenic (As) in aquifers. Here, the biogeochemical control on As mobility was investigated in batch experiments using redox cycling bioreactors and As- and SO42--amended sediment. Redox potential (Eh) oscillations between anoxic (-300-0 mV) and oxic condition (0-500 mV) were implemented by automatically modulating an admixture of N2/CO2 or compressed air. A carbon source (cellobiose, a monomer of cellulose) was added at the beginning of each reducing cycle to stimulate the metabolism of the native microbial community. Results show that successive redox cycles can decrease arsenic mobility by up to 92% during reducing conditions. Anoxic conditions drive mainly the conversion of soluble As(V) to As(III) in contrast to oxic conditions. Phylogenetic analyses of 16S rRNA amplified from the sediments revealed the presence of sulfate and iron - reducing bacteria, confirming that sulfate and iron reduction are key factors for As immobilization from the aqueous phase. As and S K-edge X-ray absorption spectroscopy suggested the association of Fe-(oxyhydr)oxides and the importance of pyrite (FeS2(s)), rather than poorly ordered mackinawite (FeS(s)), for As sequestration under oxidizing and reducing conditions, respectively. Finally, these findings suggest a role for elemental sulfur in mediating aqueous thioarsenates formation in As-contaminated groundwater of the Mekong delta.
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Affiliation(s)
- Van T H Phan
- University Grenoble Alps, CNRS, IRD, IFSTTAR, Institut des Sciences de la Terre (ISTerre), 38000 Grenoble, France; Ho Chi Minh City University of Technology (HCMUT), Vietnam National University - Ho Chi Minh City (VNU-HCM), 268 Ly Thuong Kiet, District 10, Ho Chi Minh City, Viet Nam.
| | - Rizlan Bernier-Latmani
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Environmental Microbiology Laboratory (EML), EPFL-ENAC-IIE-EML, Station 6, CH-1015 Lausanne, Switzerland
| | - Delphine Tisserand
- University Grenoble Alps, CNRS, IRD, IFSTTAR, Institut des Sciences de la Terre (ISTerre), 38000 Grenoble, France
| | | | - Pierre Le Pape
- Institut de Mineralogie, de Physique des Materiaux et de Cosmochimie (IMPMC), UMR 7590 CNRS-UPMC-IRD-MNHN, 4 place Jussieu, 75252 Paris cedex 05, France
| | - Manon Frutschi
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Environmental Microbiology Laboratory (EML), EPFL-ENAC-IIE-EML, Station 6, CH-1015 Lausanne, Switzerland
| | - Antoine Gehin
- University Grenoble Alps, CNRS, IRD, IFSTTAR, Institut des Sciences de la Terre (ISTerre), 38000 Grenoble, France
| | - Raoul-Marie Couture
- Département de Chimie, Université Laval, 1045 Avenue de la Médecine, Québec, QC G1V 0A6, Canada
| | - Laurent Charlet
- University Grenoble Alps, CNRS, IRD, IFSTTAR, Institut des Sciences de la Terre (ISTerre), 38000 Grenoble, France
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27
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Bettenworth V, Steinfeld B, Duin H, Petersen K, Streit WR, Bischofs I, Becker A. Phenotypic Heterogeneity in Bacterial Quorum Sensing Systems. J Mol Biol 2019; 431:4530-4546. [PMID: 31051177 DOI: 10.1016/j.jmb.2019.04.036] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Revised: 04/19/2019] [Accepted: 04/22/2019] [Indexed: 12/11/2022]
Abstract
Quorum sensing is usually thought of as a collective behavior in which all members of a population partake. However, over the last decade, several reports of phenotypic heterogeneity in quorum sensing-related gene expression have been put forward, thus challenging this view. In the respective systems, cells of isogenic populations did not contribute equally to autoinducer production or target gene activation, and in some cases, the fraction of contributing cells was modulated by environmental factors. Here, we look into potential origins of these incidences and into how initial cell-to-cell variations might be amplified to establish distinct phenotypic heterogeneity. We furthermore discuss potential functions heterogeneity in bacterial quorum sensing systems could serve: as a preparation for environmental fluctuations (bet hedging), as a more cost-effective way of producing public goods (division of labor), as a loophole for genotypic cooperators when faced with non-contributing mutants (cheat protection), or simply as a means to fine-tune the output of the population as a whole (output modulation). We illustrate certain aspects of these recent developments with the model organisms Sinorhizobium meliloti, Sinorhizobium fredii and Bacillus subtilis, which possess quorum sensing systems of different complexity, but all show phenotypic heterogeneity therein.
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Affiliation(s)
- Vera Bettenworth
- Center for Synthetic Microbiology (SYNMIKRO), Philipps-Universität Marburg, 35043 Marburg, Germany; Faculty of Biology, Philipps-Universität Marburg, 35043 Marburg, Germany.
| | - Benedikt Steinfeld
- BioQuant Center of the University of Heidelberg, 69120 Heidelberg, Germany; Center for Molecular Biology (ZMBH), University of Heidelberg, 69120 Heidelberg, Germany; Max-Planck-Institute for Terrestrial Microbiology, 35043 Marburg, Germany.
| | - Hilke Duin
- Department of Microbiology and Biotechnology, University of Hamburg, 22609 Hamburg, Germany.
| | - Katrin Petersen
- Department of Microbiology and Biotechnology, University of Hamburg, 22609 Hamburg, Germany.
| | - Wolfgang R Streit
- Department of Microbiology and Biotechnology, University of Hamburg, 22609 Hamburg, Germany.
| | - Ilka Bischofs
- BioQuant Center of the University of Heidelberg, 69120 Heidelberg, Germany; Center for Molecular Biology (ZMBH), University of Heidelberg, 69120 Heidelberg, Germany; Max-Planck-Institute for Terrestrial Microbiology, 35043 Marburg, Germany.
| | - Anke Becker
- Center for Synthetic Microbiology (SYNMIKRO), Philipps-Universität Marburg, 35043 Marburg, Germany; Faculty of Biology, Philipps-Universität Marburg, 35043 Marburg, Germany.
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28
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Acosta-Jurado S, Rodríguez-Navarro DN, Kawaharada Y, Rodríguez-Carvajal MA, Gil-Serrano A, Soria-Díaz ME, Pérez-Montaño F, Fernández-Perea J, Niu Y, Alias-Villegas C, Jiménez-Guerrero I, Navarro-Gómez P, López-Baena FJ, Kelly S, Sandal N, Stougaard J, Ruiz-Sainz JE, Vinardell JM. Sinorhizobium fredii HH103 nolR and nodD2 mutants gain capacity for infection thread invasion of Lotus japonicus Gifu and Lotus burttii. Environ Microbiol 2019; 21:1718-1739. [PMID: 30839140 DOI: 10.1111/1462-2920.14584] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 03/04/2019] [Accepted: 03/04/2019] [Indexed: 02/01/2023]
Abstract
Sinorhizobium fredii HH103 RifR , a broad-host-range rhizobial strain, forms ineffective nodules with Lotus japonicus but induces nitrogen-fixing nodules in Lotus burttii roots that are infected by intercellular entry. Here we show that HH103 RifR nolR or nodD2 mutants gain the ability to induce infection thread formation and to form nitrogen-fixing nodules in L. japonicus Gifu. Microscopy studies showed that the mode of infection of L. burttii roots by the nodD2 and nolR mutants switched from intercellular entry to infection threads (ITs). In the presence of the isoflavone genistein, both mutants overproduced Nod-factors. Transcriptomic analyses showed that, in the presence of Lotus japonicus Gifu root exudates, genes related to Nod factors production were overexpressed in both mutants in comparison to HH103 RifR . Complementation of the nodD2 and nolR mutants provoked a decrease in Nod-factor production, the incapacity to form nitrogen-fixing nodules with L. japonicus Gifu and restored the intercellular way of infection in L. burttii. Thus, the capacity of S. fredii HH103 RifR nodD2 and nolR mutants to infect L. burttii and L. japonicus Gifu by ITs and fix nitrogen L. japonicus Gifu might be correlated with Nod-factor overproduction, although other bacterial symbiotic signals could also be involved.
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Affiliation(s)
- Sebastián Acosta-Jurado
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, C.P., 41012, Sevilla, Spain
| | | | - Yasuyuki Kawaharada
- Department of Molecular Biology and Genetics, Centre for Carbohydrate Recognition and Signalling, Aarhus University, Gustav Wieds Vej 10, Aarhus, CDK-8000, Denmark.,Department of Plant BioSciences, Faculty of Agriculture, Iwate University, 3-18-8 Ueda, Morioka, Iwate, 020-8550, Japan
| | - Miguel A Rodríguez-Carvajal
- Departamento de Química Orgánica, Facultad de Química, Universidad de Sevilla, Calle Profesor García González 1, C. P, 41012, Sevilla, Spain
| | - Antonio Gil-Serrano
- Departamento de Química Orgánica, Facultad de Química, Universidad de Sevilla, Calle Profesor García González 1, C. P, 41012, Sevilla, Spain
| | - María E Soria-Díaz
- Servicio de Espectrometría de Masas, Centro de Investigación, Tecnología e Innovación (CITIUS), Universidad de Sevilla, Sevilla, Spain
| | - Francisco Pérez-Montaño
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, C.P., 41012, Sevilla, Spain
| | - Juan Fernández-Perea
- IFAPA, Centro Las Torres-Tomejil, Apartado Oficial 41200, Alcalá del Río, Sevilla, Spain
| | - Yanbo Niu
- Department of Resources and Environmental Microbiology, Institute of Microbiology, Heilongjiang Academy of Sciences, No. 68, Zhaolin Street, Daoli District, Harbin, Heilongjiang Province, China
| | - Cynthia Alias-Villegas
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, C.P., 41012, Sevilla, Spain
| | - Irene Jiménez-Guerrero
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, C.P., 41012, Sevilla, Spain
| | - Pilar Navarro-Gómez
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, C.P., 41012, Sevilla, Spain
| | - Francisco Javier López-Baena
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, C.P., 41012, Sevilla, Spain
| | - Simon Kelly
- Department of Molecular Biology and Genetics, Centre for Carbohydrate Recognition and Signalling, Aarhus University, Gustav Wieds Vej 10, Aarhus, CDK-8000, Denmark
| | - Niels Sandal
- Department of Molecular Biology and Genetics, Centre for Carbohydrate Recognition and Signalling, Aarhus University, Gustav Wieds Vej 10, Aarhus, CDK-8000, Denmark
| | - Jens Stougaard
- Department of Molecular Biology and Genetics, Centre for Carbohydrate Recognition and Signalling, Aarhus University, Gustav Wieds Vej 10, Aarhus, CDK-8000, Denmark
| | - José E Ruiz-Sainz
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, C.P., 41012, Sevilla, Spain
| | - José-María Vinardell
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, C.P., 41012, Sevilla, Spain
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29
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Cherni AE, Perret X. Deletion of rRNA Operons of Sinorhizobium fredii Strain NGR234 and Impact on Symbiosis With Legumes. Front Microbiol 2019; 10:154. [PMID: 30814981 PMCID: PMC6381291 DOI: 10.3389/fmicb.2019.00154] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 01/22/2019] [Indexed: 01/08/2023] Open
Abstract
During their lifecycle, from free-living soil bacteria to endosymbiotic nitrogen-fixing bacteroids of legumes, rhizobia must colonize, and cope with environments where nutrient concentrations and compositions vary greatly. Bacterial colonization of legume rhizospheres and of root surfaces is subject to a fierce competition for plant exudates. By contrast root nodules offer to rhizobia sheltered nutrient-rich environments within which the cells that successfully propagated via infection threads can rapidly multiply. To explore the effects on symbiosis of a slower rhizobia growth and metabolism, we deleted one or two copies of the three functional rRNA operons of the promiscuous Sinorhizobium fredii strain NGR234 and examined the impact of these mutations on free-living and symbiotic lifestyles. Strains with two functional rRNA operons (NGRΔrRNA1 and NGRΔrRNA3) grew almost as rapidly as NGR234, and NGRΔrRNA1 was as proficient as the parent strain on all of the five legume species tested. By contrast, the NGRΔrRNA1,3 double mutant, which carried a single rRNA operon and grew significantly slower than NGR234, had a reduced symbiotic proficiency on Cajanus cajan, Macroptilium atropurpureum, Tephrosia vogelii, and Vigna unguiculata. In addition, while NGRΔrRNA1 and NGR234 equally competed for nodulation of V. unguiculata, strain NGRΔrRNA1,3 was clearly outcompeted by wild-type. Surprisingly, on Leucaena leucocephala, NGRΔrRNA1,3 was the most proficient strain and competed equally NGR234 for nodule occupation. Together, these results indicate that for strains with otherwise identical repertoires of symbiotic genes, a faster growth on roots and/or inside plant tissues may contribute to secure access to nodules of some hosts. By contrast, other legumes such as L. leucocephala appear as less selective and capable of providing symbiotic environments susceptible to accommodate strains with a broader spectrum of competences.
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Affiliation(s)
- Ala Eddine Cherni
- Microbiology Unit, Department of Botany and Plant Biology, Sciences III, University of Geneva, Geneva, Switzerland
| | - Xavier Perret
- Microbiology Unit, Department of Botany and Plant Biology, Sciences III, University of Geneva, Geneva, Switzerland
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30
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Wang D, Couderc F, Tian CF, Gu W, Liu LX, Poinsot V. Conserved Composition of Nod Factors and Exopolysaccharides Produced by Different Phylogenetic Lineage Sinorhizobium Strains Nodulating Soybean. Front Microbiol 2018; 9:2852. [PMID: 30534119 PMCID: PMC6275314 DOI: 10.3389/fmicb.2018.02852] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 11/06/2018] [Indexed: 12/31/2022] Open
Abstract
The structural variation of symbiotic signals released by rhizobia determines the specificity of their interaction with legume plants. Previous studies showed that Sinorhizobium strains from different phylogenetic lineages had different symbiotic performance on certain cultivated soybeans. Whether they released similar or different symbiotic signals remained unclear. In this study, we compared their nod and exo gene clusters and made a detailed structural analysis of Nod factors and EPS by ESI-MS/MS and two dimensions NMR. Even if there are some differences among nod or exo gene clusters; they produced much conserved Nod factor and EPS compositions. The Nod factors consist of a cocktail of β-(1, 4)-linked tri-, tetra-, and pentamers of N-acetyl-D-glucosamine (GlcNAc). The C2 position on the non-reducing terminal end is modified by a lipid chain that contains 16 or 18 atoms of carbon–with or without unsaturations-, and the C6 position on the reducing residue is decorated by a fucose or a 2-O-methylfucose. Their EPS are composed of glucose, galactose, glucuronic acid, pyruvic acid in the ratios 5:1:2:1 or 6:1:2:1. These findings indicate that soybean cultivar compatibility of Sinorhizobium strains does not result from Nod factor or EPS structure variations. The structure comparison of the soybean microbionts with other Sinorhizobium strains showed that Nod factor structures of soybean microbionts are much conserved, although there are no specific genes shared by the soybean microsymbionts. EPS produced by Sinorhizobium strains are different from those of Bradyrhizobium. All above is consistent with the previous deduction that Nod factor structures are related to host range, while those of EPS are connected with phylogeny.
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Affiliation(s)
- Dan Wang
- Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Key Laboratory of Plant Nutrition and Fertilizer in South Region, Ministry of Agriculture, Guangdong Key Laboratory of Nutrient Cycling and Farmland Conservation, Guangzhou, China.,Laboratoire des IMRCP, UMR5623 Université Paul Sabatier, CNRS, Toulouse, France.,State Key Laboratory of Agrobiotechnology, and College of Biological Sciences, China Agricultural University, Beijing, China
| | - François Couderc
- Laboratoire des IMRCP, UMR5623 Université Paul Sabatier, CNRS, Toulouse, France
| | - Chang Fu Tian
- State Key Laboratory of Agrobiotechnology, and College of Biological Sciences, China Agricultural University, Beijing, China
| | - Wenjie Gu
- Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Key Laboratory of Plant Nutrition and Fertilizer in South Region, Ministry of Agriculture, Guangdong Key Laboratory of Nutrient Cycling and Farmland Conservation, Guangzhou, China
| | - Li Xue Liu
- State Key Laboratory of Agrobiotechnology, and College of Biological Sciences, China Agricultural University, Beijing, China
| | - Verena Poinsot
- Laboratoire des IMRCP, UMR5623 Université Paul Sabatier, CNRS, Toulouse, France
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Temprano-Vera F, Rodríguez-Navarro DN, Acosta-Jurado S, Perret X, Fossou RK, Navarro-Gómez P, Zhen T, Yu D, An Q, Buendía-Clavería AM, Moreno J, López-Baena FJ, Ruiz-Sainz JE, Vinardell JM. Sinorhizobium fredii Strains HH103 and NGR234 Form Nitrogen Fixing Nodules With Diverse Wild Soybeans ( Glycine soja) From Central China but Are Ineffective on Northern China Accessions. Front Microbiol 2018; 9:2843. [PMID: 30519234 PMCID: PMC6258812 DOI: 10.3389/fmicb.2018.02843] [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: 08/09/2018] [Accepted: 11/05/2018] [Indexed: 11/18/2022] Open
Abstract
Sinorhizobium fredii indigenous populations are prevalent in provinces of Central China whereas Bradyrhizobium species (Bradyrhizobium japonicum, B. diazoefficiens, B. elkanii, and others) are more abundant in northern and southern provinces. The symbiotic properties of different soybean rhizobia have been investigated with 40 different wild soybean (Glycine soja) accessions from China, Japan, Russia, and South Korea. Bradyrhizobial strains nodulated all the wild soybeans tested, albeit efficiency of nitrogen fixation varied considerably among accessions. The symbiotic capacity of S. fredii HH103 with wild soybeans from Central China was clearly better than with the accessions found elsewhere. S. fredii NGR234, the rhizobial strain showing the broadest host range ever described, also formed nitrogen-fixing nodules with different G. soja accessions from Central China. To our knowledge, this is the first report describing an effective symbiosis between S. fredii NGR234 and G. soja. Mobilization of the S. fredii HH103 symbiotic plasmid to a NGR234 pSym-cured derivative (strain NGR234C) yielded transconjugants that formed ineffective nodules with G. max cv. Williams 82 and G. soja accession CH4. By contrast, transfer of the symbiotic plasmid pNGR234a to a pSym-cured derivative of S. fredii USDA193 generated transconjugants that effectively nodulated G. soja accession CH4 but failed to nodulate with G. max cv. Williams 82. These results indicate that intra-specific transference of the S. fredii symbiotic plasmids generates new strains with unpredictable symbiotic properties, probably due to the occurrence of new combinations of symbiotic signals.
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Affiliation(s)
| | | | - Sebastian Acosta-Jurado
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avenida Reina Mercedes, Seville, Spain
| | - Xavier Perret
- Department of Botany and Plant Biology, University of Geneva, Geneva, Switzerland
| | - Romain K Fossou
- Department of Botany and Plant Biology, University of Geneva, Geneva, Switzerland
| | - Pilar Navarro-Gómez
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avenida Reina Mercedes, Seville, Spain
| | - Tao Zhen
- Institute of Microbiology, Heilongjiang Academy of Sciences, Harbin, China
| | - Deshui Yu
- Institute of Microbiology, Heilongjiang Academy of Sciences, Harbin, China
| | - Qi An
- Institute of Microbiology, Heilongjiang Academy of Sciences, Harbin, China
| | - Ana Maria Buendía-Clavería
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avenida Reina Mercedes, Seville, Spain
| | - Javier Moreno
- Departamento de Biología Celular, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - Francisco Javier López-Baena
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avenida Reina Mercedes, Seville, Spain
| | - Jose Enrique Ruiz-Sainz
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avenida Reina Mercedes, Seville, Spain
| | - Jose Maria Vinardell
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avenida Reina Mercedes, Seville, Spain
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32
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Basile LA, Zalguizuri A, Briones G, Lepek VC. Two Rieske Fe/S Proteins and TAT System in Mesorhizobium loti MAFF303099: Differential Regulation and Roles on Nodulation. FRONTIERS IN PLANT SCIENCE 2018; 9:1686. [PMID: 30515183 PMCID: PMC6256036 DOI: 10.3389/fpls.2018.01686] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 10/30/2018] [Indexed: 06/09/2023]
Abstract
Mesorhizobium loti MAFF303099 is a rhizobial strain that nodulates Lotus spp. A M. loti MAFF303099 mutant strain affected in the tatC gene was generated. This strain presented an altered protein secretion level to the culture supernatant and also a higher sensitivity to SDS. Its nodulation phenotype on Lotus showed the induction of small and colorless nodules, and in a larger number than those induced by the wild-type strain. In addition, these nodules presented defects in the degree of occupation by rhizobia. Two Rieske Fe/S proteins, encoded by the mll2707 and mlr0970 genes, were predicted as potential Tat substrates in M. loti MAFF303099. The transcriptional expression of mll2707 and mlr0970 genes was analyzed under different oxygen growth conditions. The mll2707 gene was expressed constitutively, while the expression of the mlr0970 gene was only detected under anaerobic and microaerophilic in vitro conditions. Both genes were down-regulated in the tatC mutant strain. mll2707 and mlr0970 mRNAs from the wild-type strain were detected in nodules. Using a translational reporter peptide fusion, we found that the Mll2707 protein was only detectable in the wild-type strain. On the other hand, although Mlr0970 protein was detected in wild-type and tatC mutant strains, its association with the membrane was favored in the wild-type strain. The tatC and the mll2707 mutant strains were affected in the cytochrome c oxidase activity. These results confirm that Mll2707 is required for cytochrome c-dependent respiration and that Tat functionality is required for the correct activity of Mll2707. The mll2707 mutant strain showed a nodulation phenotype similar to the tatC mutant strain, although it presented only a slight difference in comparison with wild-type strain in terms of nodule occupation. No defective phenotype was observed in the nodulation with the mlr0970 mutant strain. These results indicate that, of the two Rieske Fe/S proteins coded by M. loti MAFF303099, only Mll2707 expression is required for the induction of effective nodules, and that the functionality of the Tat system is necessary not only for the correct function of this protein, but also for some other protein required in an earlier stage of the nodulation process.
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Liu W, Wang Y, Jing C. Transcriptome analysis of silver, palladium, and selenium stresses in Pantoea sp. IMH. CHEMOSPHERE 2018; 208:50-58. [PMID: 29860144 DOI: 10.1016/j.chemosphere.2018.05.169] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 05/18/2018] [Accepted: 05/27/2018] [Indexed: 06/08/2023]
Abstract
Heavy metal contamination is a significant environmental issue. Using bacteria for removal and reduction of heavy metals is an attractive alternative owing to its low-cost and eco-friendly properties. However, the mechanisms of resistance to and reduction of Ag(I), Pd(II), and Se(IV), especially in the same strain, remain unclear. Here, Pantoea sp. IMH was examed for its reduction of Ag(I), Pd(II), and Se(IV) to nanoparticles (NPs), and the molecular mechanism was investigated by transcriptome analysis. The results revealed that genes encoding binding, transport, catalytic activity, and metabolism were differentially expressed in cells exposed to Ag(I), Pd(II), and Se(IV). The same resistance mechanisms for all metals included multiple stress resistance protein BhsA and glutathione detoxification metabolism. However, zinc transport protein and sulfate metabolism played an important role in the resistance to cationic metals (Ag+ and Pd2+), while the oxalate transporter and arsenic resistance mechanisms were specifically involved in the resistance to and reduction of anion (SeO32-). In addition, Ag(I) was speculated to be reduced to AgNPs by glucose and cytochrome CpxP was involved in Pd(II) reduction. Our results provided new clues on the mechanisms of resistance to and reduction of Ag(I), Pd(II), and Se(IV).
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Affiliation(s)
- Wenjing Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yanan Wang
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Chuanyong Jing
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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Jiao J, Ni M, Zhang B, Zhang Z, Young JPW, Chan TF, Chen WX, Lam HM, Tian CF. Coordinated regulation of core and accessory genes in the multipartite genome of Sinorhizobium fredii. PLoS Genet 2018; 14:e1007428. [PMID: 29795552 PMCID: PMC5991415 DOI: 10.1371/journal.pgen.1007428] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Revised: 06/06/2018] [Accepted: 05/18/2018] [Indexed: 01/18/2023] Open
Abstract
Prokaryotes benefit from having accessory genes, but it is unclear how accessory genes can be linked with the core regulatory network when developing adaptations to new niches. Here we determined hierarchical core/accessory subsets in the multipartite pangenome (composed of genes from the chromosome, chromid and plasmids) of the soybean microsymbiont Sinorhizobium fredii by comparing twelve Sinorhizobium genomes. Transcriptomes of two S. fredii strains at mid-log and stationary growth phases and in symbiotic conditions were obtained. The average level of gene expression, variation of expression between different conditions, and gene connectivity within the co-expression network were positively correlated with the gene conservation level from strain-specific accessory genes to genus core. Condition-dependent transcriptomes exhibited adaptive transcriptional changes in pangenome subsets shared by the two strains, while strain-dependent transcriptomes were enriched with accessory genes on the chromid. Proportionally more chromid genes than plasmid genes were co-expressed with chromosomal genes, while plasmid genes had a higher within-replicon connectivity in expression than chromid ones. However, key nitrogen fixation genes on the symbiosis plasmid were characterized by high connectivity in both within- and between-replicon analyses. Among those genes with host-specific upregulation patterns, chromosomal znu and mdt operons, encoding a conserved high-affinity zinc transporter and an accessory multi-drug efflux system, respectively, were experimentally demonstrated to be involved in host-specific symbiotic adaptation. These findings highlight the importance of integrative regulation of hierarchical core/accessory components in the multipartite genome of bacteria during niche adaptation and in shaping the prokaryotic pangenome in the long run.
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Affiliation(s)
- Jian Jiao
- State Key Laboratory of Agrobiotechnology, and College of Biological Sciences, China Agricultural University, Beijing, China
- Rhizobium Research Center, China Agricultural University, Beijing, China
| | - Meng Ni
- School of Life Sciences and Center for Soybean Research of the Partner State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Biliang Zhang
- State Key Laboratory of Agrobiotechnology, and College of Biological Sciences, China Agricultural University, Beijing, China
| | - Ziding Zhang
- State Key Laboratory of Agrobiotechnology, and College of Biological Sciences, China Agricultural University, Beijing, China
| | | | - Ting-Fung Chan
- School of Life Sciences and Center for Soybean Research of the Partner State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Wen Xin Chen
- State Key Laboratory of Agrobiotechnology, and College of Biological Sciences, China Agricultural University, Beijing, China
- Rhizobium Research Center, China Agricultural University, Beijing, China
| | - Hon-Ming Lam
- School of Life Sciences and Center for Soybean Research of the Partner State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Chang Fu Tian
- State Key Laboratory of Agrobiotechnology, and College of Biological Sciences, China Agricultural University, Beijing, China
- Rhizobium Research Center, China Agricultural University, Beijing, China
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Durán D, Imperial J, Palacios J, Ruiz-Argüeso T, Göttfert M, Zehner S, Rey L. Characterization of a novel MIIA domain-containing protein (MdcE) in Bradyrhizobium spp. FEMS Microbiol Lett 2018; 365:4769627. [PMID: 29281013 DOI: 10.1093/femsle/fnx276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 12/20/2017] [Indexed: 11/14/2022] Open
Abstract
Several genes coding for proteins with metal ion-inducible autocleavage (MIIA) domains were identified in type III secretion system tts gene clusters from draft genomes of recently isolated Bradyrhizobium spp. MIIA domains have been first described in the effectors NopE1 and NopE2 of Bradyrhizobium diazoefficiens USDA 110. All identified genes are preceded by tts box promoter motifs. The identified proteins contain one or two MIIA domains. A phylogenetic analysis of 35 MIIA domain sequences from 16 Bradyrhizobium strains revealed four groups. The protein from Bradyrhizobium sp. LmjC strain contains a single MIIA domain and was designated MdcE (MdcELmjC). It was expressed as a fusion to maltose-binding protein (MalE) in Escherichia coli and subsequently purified by affinity chromatography. Recombinant MalE-MdcELmjC-Strep protein exhibited autocleavage in the presence of Ca2+, Cu2+, Cd2+ and Mn2+, but not in the presence of Mg2+, Ni2+ or Co2+. Site-directed mutagenesis at the predicted cleavage site abolished autocleavage activity of MdcELmjC. An LmjC mdcE- mutant was impaired in the ability to nodulate Lupinus angustifolius and Macroptilium atropurpureum.
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Affiliation(s)
- David Durán
- Centro de Biotecnología y Genómica de Plantas UPM-INIA, Campus de Montegancedo, 28223 Pozuelo de Alarcón, Spain and Departamento de Biotecnología y Biología Vegetal, ETSI Agrómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid
| | - Juan Imperial
- Centro de Biotecnología y Genómica de Plantas UPM-INIA, Campus de Montegancedo, 28223 Pozuelo de Alarcón, Spain and Departamento de Biotecnología y Biología Vegetal, ETSI Agrómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid.,Instituto de Ciencias Agrarias (ICA), Consejo Superior Investigaciones Científicas, Serrano 115, bis, 28006 Madrid, Spain
| | - José Palacios
- Centro de Biotecnología y Genómica de Plantas UPM-INIA, Campus de Montegancedo, 28223 Pozuelo de Alarcón, Spain and Departamento de Biotecnología y Biología Vegetal, ETSI Agrómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid
| | - Tomás Ruiz-Argüeso
- Centro de Biotecnología y Genómica de Plantas UPM-INIA, Campus de Montegancedo, 28223 Pozuelo de Alarcón, Spain and Departamento de Biotecnología y Biología Vegetal, ETSI Agrómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid
| | - Michael Göttfert
- Institute of Genetics, Technische Universität Dresden, Helmholtzstrasse 10, 01062 Dresden, Germany
| | - Susanne Zehner
- Institute of Genetics, Technische Universität Dresden, Helmholtzstrasse 10, 01062 Dresden, Germany
| | - Luis Rey
- Centro de Biotecnología y Genómica de Plantas UPM-INIA, Campus de Montegancedo, 28223 Pozuelo de Alarcón, Spain and Departamento de Biotecnología y Biología Vegetal, ETSI Agrómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid
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Abstract
Rhizobia are some of the best-studied plant microbiota. These oligotrophic Alphaproteobacteria or Betaproteobacteria form symbioses with their legume hosts. Rhizobia must exist in soil and compete with other members of the microbiota before infecting legumes and forming N2-fixing bacteroids. These dramatic lifestyle and developmental changes are underpinned by large genomes and even more complex pan-genomes, which encompass the whole population and are subject to rapid genetic exchange. The ability to respond to plant signals and chemoattractants and to colonize nutrient-rich roots are crucial for the competitive success of these bacteria. The availability of a large body of genomic, physiological, biochemical and ecological studies makes rhizobia unique models for investigating community interactions and plant colonization.
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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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Transcriptomic Studies of the Effect of nod Gene-Inducing Molecules in Rhizobia: Different Weapons, One Purpose. Genes (Basel) 2017; 9:genes9010001. [PMID: 29267254 PMCID: PMC5793154 DOI: 10.3390/genes9010001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 12/07/2017] [Accepted: 12/15/2017] [Indexed: 12/16/2022] Open
Abstract
Simultaneous quantification of transcripts of the whole bacterial genome allows the analysis of the global transcriptional response under changing conditions. RNA-seq and microarrays are the most used techniques to measure these transcriptomic changes, and both complement each other in transcriptome profiling. In this review, we exhaustively compiled the symbiosis-related transcriptomic reports (microarrays and RNA sequencing) carried out hitherto in rhizobia. This review is specially focused on transcriptomic changes that takes place when five rhizobial species, Bradyrhizobium japonicum (=diazoefficiens) USDA 110, Rhizobium leguminosarum biovar viciae 3841, Rhizobium tropici CIAT 899, Sinorhizobium (=Ensifer) meliloti 1021 and S. fredii HH103, recognize inducing flavonoids, plant-exuded phenolic compounds that activate the biosynthesis and export of Nod factors (NF) in all analysed rhizobia. Interestingly, our global transcriptomic comparison also indicates that each rhizobial species possesses its own arsenal of molecular weapons accompanying the set of NF in order to establish a successful interaction with host legumes.
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Yan H, Xie JB, Ji ZJ, Yuan N, Tian CF, Ji SK, Wu ZY, Zhong L, Chen WX, Du ZL, Wang ET, Chen WF. Evolutionarily Conserved nodE, nodO, T1SS, and Hydrogenase System in Rhizobia of Astragalus membranaceus and Caragana intermedia. Front Microbiol 2017; 8:2282. [PMID: 29209294 PMCID: PMC5702008 DOI: 10.3389/fmicb.2017.02282] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 11/06/2017] [Indexed: 02/01/2023] Open
Abstract
Mesorhizobium species are the main microsymbionts associated with the medicinal or sand-fixation plants Astragalus membranaceus and Caragana intermedia (AC) in temperate regions of China, while all the Mesorhizobium strains isolated from each of these plants could nodulate both of them. However, Rhizobium yanglingense strain CCBAU01603 could nodulate AC plants and it's a high efficiency symbiotic and competitive strain with Caragana. Therefore, the common features shared by these symbiotic rhizobia in genera of Mesorhizobium and Rhizobium still remained undiscovered. In order to study the genomic background influencing the host preference of these AC symbiotic strains, the whole genomes of two (M. silamurunense CCBAU01550, M. silamurunense CCBAU45272) and five representative strains (M. septentrionale CCBAU01583, M. amorphae CCBAU01570, M. caraganae CCBAU01502, M. temperatum CCBAU01399, and R. yanglingense CCBAU01603) originally isolated from AC plants were sequenced, respectively. As results, type III secretion systems (T3SS) of AC rhizobia evolved in an irregular pattern, while an evolutionarily specific region including nodE, nodO, T1SS, and a hydrogenase system was detected to be conserved in all these AC rhizobia. Moreover, nodO was verified to be prevalently distributed in other AC rhizobia and was presumed as a factor affecting the nodule formation process. In conclusion, this research interpreted the multifactorial features of the AC rhizobia that may be associated with their host specificity at cross-nodulation group, including nodE, nodZ, T1SS as the possible main determinants; and nodO, hydrogenase system, and T3SS as factors regulating the bacteroid formation or nitrogen fixation efficiency.
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Affiliation(s)
- Hui Yan
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences and Rhizobium Research Center, China Agricultural University, Beijing, China.,State Key Laboratory of Animal Nutrition, Beijing Engineering Technology Research Center of Raw Milk Quality and Safety Control, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Jian Bo Xie
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Zhao Jun Ji
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences and Rhizobium Research Center, China Agricultural University, Beijing, China
| | - Na Yuan
- Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - Chang Fu Tian
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences and Rhizobium Research Center, China Agricultural University, Beijing, China
| | - Shou Kun Ji
- State Key Laboratory of Animal Nutrition, Beijing Engineering Technology Research Center of Raw Milk Quality and Safety Control, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Zhong Yu Wu
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences and Rhizobium Research Center, China Agricultural University, Beijing, China
| | - Liang Zhong
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences and Rhizobium Research Center, China Agricultural University, Beijing, China
| | - Wen Xin Chen
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences and Rhizobium Research Center, China Agricultural University, Beijing, China
| | - Zheng Lin Du
- Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - En Tao Wang
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico, Mexico
| | - Wen Feng Chen
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences and Rhizobium Research Center, China Agricultural University, Beijing, China
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Tampakaki AP, Fotiadis CT, Ntatsi G, Savvas D. A novel symbiovar (aegeanense) of the genus Ensifer nodulates Vigna unguiculata. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2017; 97:4314-4325. [PMID: 28220509 DOI: 10.1002/jsfa.8281] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 02/10/2017] [Accepted: 02/16/2017] [Indexed: 06/06/2023]
Abstract
BACKGROUND Cowpea (Vigna unguiculata) forms nitrogen-fixing root nodules with diverse symbiotic bacteria, mainly slow-growing rhizobial species belonging to the genus Bradyrhizobium, although a few studies have reported the isolation of fast-growing rhizobia under laboratory and field conditions. Although much research has been done on cowpea-nodulating bacteria in various countries around the world, very limited information is available on cowpea rhizobia in European soils. The aim of this study was to study the genetic and phenotypic diversity of indigenous cowpea-nodulating rhizobia in Greece. RESULTS The genetic diversity of indigenous rhizobia associated with cowpea was investigated through a polyphasic approach. ERIC-PCR based fingerprinting analysis grouped the isolates into three groups. Based on the analysis of the 16S rRNA genes, IGS and on the concatenation of six housekeeping genes (recA, glnII, gyrB, truA, thrA and SMc00019), rhizobial isolates were classified within the species Ensifer fredii. However, symbiotic gene phylogenies, based on nodC, nifH and rhcRST genes, showed that the Ensifer isolates are markedly diverged from type and reference strains of E. fredii and formed one clearly separate cluster. The E. fredii strains were able to nodulate and fix nitrogen in cowpea but not in soybean and common bean. CONCLUSION The present study showed that cowpea is nodulated under field conditions by fast-growing rhizobia belonging to the species E. fredii. Based on the phylogenies, similarity levels of symbiotic genes and the host range, the Ensifer isolates may constitute a new symbiovar for which the name 'aegeanense' is proposed. © 2017 Society of Chemical Industry.
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Affiliation(s)
- Anastasia P Tampakaki
- Laboratory of General and Agricultural Microbiology, Department of Crop Science, Agricultural University of Athens, Athens, Greece
| | - Christos T Fotiadis
- Laboratory of General and Agricultural Microbiology, Department of Crop Science, Agricultural University of Athens, Athens, Greece
| | - Georgia Ntatsi
- Laboratory of Vegetable Production, Department of Crop Science, Agricultural University of Athens, Athens, Greece
| | - Dimitrios Savvas
- Laboratory of Vegetable Production, Department of Crop Science, Agricultural University of Athens, Athens, Greece
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Osman WAM, van Berkum P, León-Barrios M, Velázquez E, Elia P, Tian R, Ardley J, Gollagher M, Seshadri R, Reddy TBK, Ivanova N, Woyke T, Pati A, Markowitz V, Baeshen MN, Baeshen NN, Kyrpides N, Reeve W. High-quality draft genome sequence of Ensifer meliloti Mlalz-1, a microsymbiont of Medicago laciniata (L.) miller collected in Lanzarote, Canary Islands, Spain. Stand Genomic Sci 2017; 12:58. [PMID: 28975015 PMCID: PMC5613336 DOI: 10.1186/s40793-017-0270-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 09/14/2017] [Indexed: 11/26/2022] Open
Abstract
10.1601/nm.1335 Mlalz-1 (INSDC = ATZD00000000) is an aerobic, motile, Gram-negative, non-spore-forming rod that was isolated from an effective nitrogen-fixing nodule of Medicago laciniata (L.) Miller from a soil sample collected near the town of Guatiza on the island of Lanzarote, the Canary Islands, Spain. This strain nodulates and forms an effective symbiosis with the highly specific host M. laciniata. This rhizobial genome was sequenced as part of the DOE Joint Genome Institute 2010 Genomic Encyclopedia for Bacteria and Archaea-Root Nodule Bacteria (GEBA-RNB) sequencing project. Here the features of 10.1601/nm.1335 Mlalz-1 are described, together with high-quality permanent draft genome sequence information and annotation. The 6,664,116 bp high-quality draft genome is arranged in 99 scaffolds of 100 contigs, containing 6314 protein-coding genes and 74 RNA-only encoding genes. Strain Mlalz-1 is closely related to 10.1601/nm.1335 10.1601/strainfinder?urlappend=%3Fid%3DIAM+12611 T, 10.1601/nm.1334 A 321T and 10.1601/nm.17831 10.1601/strainfinder?urlappend=%3Fid%3DORS+1407 T, based on 16S rRNA gene sequences. gANI values of ≥98.1% support the classification of strain Mlalz-1 as 10.1601/nm.1335. Nodulation of M. laciniata requires a specific nodC allele, and the nodC gene of strain Mlalz-1 shares ≥98% sequence identity with nodC of M. laciniata-nodulating 10.1601/nm.1328 strains, but ≤93% with nodC of 10.1601/nm.1328 strains that nodulate other Medicago species. Strain Mlalz-1 is unique among sequenced 10.1601/nm.1335 strains in possessing genes encoding components of a T2SS and in having two versions of the adaptive acid tolerance response lpiA-acvB operon. In 10.1601/nm.1334 strain 10.1601/strainfinder?urlappend=%3Fid%3DWSM+419, lpiA is essential for enhancing survival in lethal acid conditions. The second copy of the lpiA-acvB operon of strain Mlalz-1 has highest sequence identity (> 96%) with that of 10.1601/nm.1334 strains, which suggests genetic recombination between strain Mlalz-1 and 10.1601/nm.1334 and the horizontal gene transfer of lpiA-acvB.
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Affiliation(s)
| | - Peter van Berkum
- U.S. Department of Agriculture, Soybean Genomics and Improvement Laboratory, Beltsville Agricultural Research Center, 10300 Baltimore Avenue, Bldg. 006, Beltsville, MD 20705 USA
| | - Milagros León-Barrios
- Departamento de Bioquímica, Microbiología, Biología Celular y Genética, Universidad de La Laguna, Tenerife, Spain
| | - Encarna Velázquez
- Departamento de Microbiología y Genetica and Instituto Hispanoluso de Investigaciones Agrarias (CIALE), Universidad de Salamanca, Salamanca, Spain
| | - Patrick Elia
- U.S. Department of Agriculture, Soybean Genomics and Improvement Laboratory, Beltsville Agricultural Research Center, 10300 Baltimore Avenue, Bldg. 006, Beltsville, MD 20705 USA
| | - Rui Tian
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, WA Australia
| | - Julie Ardley
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, WA Australia
| | - Margaret Gollagher
- Curtin University Sustainability Policy Institute, Curtin University, Bentley, WA Australia
| | | | | | | | - Tanja Woyke
- DOE Joint Genome Institute, Walnut Creek, CA USA
| | - Amrita Pati
- Biological Data Management and Technology Center, Lawrence Berkeley National Laboratory, Berkeley, CA USA
| | - Victor Markowitz
- Biological Data Management and Technology Center, Lawrence Berkeley National Laboratory, Berkeley, CA USA
| | - Mohamed N. Baeshen
- Department of Biology, Faculty of Science, University of Jeddah, Jeddah, Saudi Arabia
| | | | | | - Wayne Reeve
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, WA Australia
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He WJ, Zhang L, Yi SY, Tang XL, Yuan QS, Guo MW, Wu AB, Qu B, Li HP, Liao YC. An aldo-keto reductase is responsible for Fusarium toxin-degrading activity in a soil Sphingomonas strain. Sci Rep 2017; 7:9549. [PMID: 28842569 PMCID: PMC5573404 DOI: 10.1038/s41598-017-08799-w] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 07/19/2017] [Indexed: 12/12/2022] Open
Abstract
Degradation of toxins by microorganisms is a promising approach for detoxification of agricultural products. Here, a bacterial strain, Sphingomonas S3-4, that has the ability to degrade the mycotoxin deoxynivalenol (DON) was isolated from wheat fields. Incubation of Fusarium-infected wheat grains with S3-4 completely eliminated DON. In S3-4 DON is catabolized into compounds with no detectable phytotoxicity, 3-oxo-DON and 3-epi-DON, via two sequential reactions. Comparative analysis of genome sequences from two DON-degrading strains, S3-4 and Devosia D17, and one non-DON-degrading strain, Sphingobium S26, combined with functional screening of a S3-4 genomic BAC library led to the discovery that a novel aldo/keto reductase superfamily member, AKR18A1, is responsible for oxidation of DON into 3-oxo-DON. DON-degrading activity is completely abolished in a mutant S3-4 strain where the AKR18A1 gene is disrupted. Recombinant AKR18A1 protein expressed in Escherichia coli catalyzed the reversible oxidation/reduction of DON at a wide range of pH values (7.5 to 11) and temperatures (10 to 50 °C). The S3-4 strain and recombinant AKR18A1 also catabolized zearalenone and the aldehydes glyoxal and methyglyoxal. The S3-4 strain and the AKR18A1 gene are promising agents for the control of Fusarium pathogens and detoxification of mycotoxins in plants and in food/feed products.
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Affiliation(s)
- Wei-Jie He
- Molecular Biotechnology Laboratory of Triticeae Crops, Huazhong Agricultural University, Wuhan, 430070, China
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Limin Zhang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Centre for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, the Chinese Academy of Sciences, Wuhan, 430071, China
| | - Shu-Yuan Yi
- Molecular Biotechnology Laboratory of Triticeae Crops, Huazhong Agricultural University, Wuhan, 430070, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xue-Ling Tang
- Molecular Biotechnology Laboratory of Triticeae Crops, Huazhong Agricultural University, Wuhan, 430070, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Qing-Song Yuan
- Molecular Biotechnology Laboratory of Triticeae Crops, Huazhong Agricultural University, Wuhan, 430070, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Mao-Wei Guo
- Molecular Biotechnology Laboratory of Triticeae Crops, Huazhong Agricultural University, Wuhan, 430070, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Ai-Bo Wu
- Molecular Biotechnology Laboratory of Triticeae Crops, Huazhong Agricultural University, Wuhan, 430070, China
- Key Laboratory of Food Safety Research Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Bo Qu
- Molecular Biotechnology Laboratory of Triticeae Crops, Huazhong Agricultural University, Wuhan, 430070, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - He-Ping Li
- Molecular Biotechnology Laboratory of Triticeae Crops, Huazhong Agricultural University, Wuhan, 430070, China
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yu-Cai Liao
- Molecular Biotechnology Laboratory of Triticeae Crops, Huazhong Agricultural University, Wuhan, 430070, China.
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
- National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, 430070, China.
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Abstract
Beneficial microbes such as rhizobia possess effector proteins that are secreted into the host cytoplasm where they modulate host-signaling pathways. Among these effectors, type 3 secreted effectors (T3Es) of rhizobia play roles in promoting nitrogen-fixing nodule symbiosis, suppressing host defenses and directly activating symbiosis-related processes. Rhizobia use the same strategy as pathogenic bacteria to suppress host defenses such as targeting the MAPK cascade. In addition, rhizobial T3E can promote root nodule symbiosis by directly activating Nod factor signaling, which bypasses Nod factor perception. The various strategies employed by beneficial microbes to promote infection and maintain viability in the host are therefore crucial for plant endosymbiosis.
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Affiliation(s)
- Hiroki Miwa
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo 183-8509, Japan
| | - Shin Okazaki
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo 183-8509, Japan.
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Defez R, Andreozzi A, Bianco C. The Overproduction of Indole-3-Acetic Acid (IAA) in Endophytes Upregulates Nitrogen Fixation in Both Bacterial Cultures and Inoculated Rice Plants. MICROBIAL ECOLOGY 2017; 74:441-452. [PMID: 28197647 DOI: 10.1007/s00248-017-0948-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 02/02/2017] [Indexed: 05/26/2023]
Abstract
Endophytic bacteria from roots and leaves of rice plants were isolated and identified in order to select the diazotrophs and improve their nitrogen-fixing abilities. The nitrogen-fixing endophytes were identified by PCR amplification of the nifH gene fragment. For this purpose, two isolates, Enterobacter cloacae RCA25 and Klebsiella variicola RCA26, and two model bacteria (Herbaspirillum seropedicae z67 and Sinorhizobium fredii NGR234) were transformed to increase the biosynthesis of the main plant auxin indole-3-acetic acid (IAA). A significant increase in the production of IAA was observed for all strains. When the expression of nifH gene and the activity of the nitrogenase enzyme were analyzed in liquid cultures, we found that they were positively affected in the IAA-overproducing endophytes as compared to the wild-type ones. Rice plants inoculated with these modified strains showed a significant upregulation of the nitrogenase activity when plants infected with the wild-type strains were used as reference. Similar results were obtained too with common bean plants infected with the S. fredii NGR234 strain. These findings suggest that IAA overproduction improves nitrogen-fixing apparatus of endophytic bacteria both in liquid cultures and in inoculated host plants. The present study highlights new perspectives to enhance nitrogen-fixing ability in non-legume crops. These strains could be used as bioinoculants to improve the growth and the yield of agricultural crops, offering an alternative to the use of chemical nitrogen fertilizers.
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Affiliation(s)
- Roberto Defez
- Institute of Biosciences and Bioresources, Via P. Castellino 111, 80131, Naples, Italy
| | - Anna Andreozzi
- Institute of Biosciences and Bioresources, Via P. Castellino 111, 80131, Naples, Italy
| | - Carmen Bianco
- Institute of Biosciences and Bioresources, Via P. Castellino 111, 80131, Naples, Italy.
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Bauer M, Knebel J, Lechner M, Pickl P, Frey E. Ecological feedback in quorum-sensing microbial populations can induce heterogeneous production of autoinducers. eLife 2017; 6. [PMID: 28741470 PMCID: PMC5526673 DOI: 10.7554/elife.25773] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Accepted: 06/15/2017] [Indexed: 12/11/2022] Open
Abstract
Autoinducers are small signaling molecules that mediate intercellular communication in microbial populations and trigger coordinated gene expression via ‘quorum sensing’. Elucidating the mechanisms that control autoinducer production is, thus, pertinent to understanding collective microbial behavior, such as virulence and bioluminescence. Recent experiments have shown a heterogeneous promoter activity of autoinducer synthase genes, suggesting that some of the isogenic cells in a population might produce autoinducers, whereas others might not. However, the mechanism underlying this phenotypic heterogeneity in quorum-sensing microbial populations has remained elusive. In our theoretical model, cells synthesize and secrete autoinducers into the environment, up-regulate their production in this self-shaped environment, and non-producers replicate faster than producers. We show that the coupling between ecological and population dynamics through quorum sensing can induce phenotypic heterogeneity in microbial populations, suggesting an alternative mechanism to stochastic gene expression in bistable gene regulatory circuits. DOI:http://dx.doi.org/10.7554/eLife.25773.001 Bacteria and other microbes can communicate with each other using chemical languages. They release small signaling molecules called autoinducers into their surroundings and sense the levels of the autoinducers in the environment. The response to these autoinducers – known as quorum sensing – can regulate how whole communities of microbes grow and behave; for example, autoinducers can alter the ability of microbes to infect humans or enable the microbes to collectively switch on light production. Recent experiments suggest that, in a population of genetically identical microbes, some individuals may produce autoinducers while others do not. The coexistence of these different “phenotypes” in one population may enable different individuals to perform different roles, or act as a “bet-hedging” strategy that helps the population to survive if it is later exposed to a stressful situation. It is not clear how microbes regulate autoinducer production so that only some individuals produce these molecules. Bauer, Knebel et al. developed a theoretical model to address this question. In the model, the microbes shape their environment by producing autoinducers and can respond to this self-shaped environment by changing their level of autoinducer production. Bauer, Knebel et al. found that this establishes a feedback loop that can result in autoinducers being produced by some individuals but not others. The next step following on from this work is to carry out experiments to test the assumptions and predictions made by the theoretical model. These findings may help to understand how the coexistence of different phenotypes affects collective behaviors, and vice versa, in populations of microbes that use quorum-sensing. DOI:http://dx.doi.org/10.7554/eLife.25773.002
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Affiliation(s)
- Matthias Bauer
- Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, Department of Physics, Ludwig-Maximilians-Universität München, München, Germany
| | - Johannes Knebel
- Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, Department of Physics, Ludwig-Maximilians-Universität München, München, Germany
| | - Matthias Lechner
- Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, Department of Physics, Ludwig-Maximilians-Universität München, München, Germany
| | - Peter Pickl
- Department of Mathematics, Ludwig-Maximilians-Universität München, München, Germany
| | - Erwin Frey
- Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, Department of Physics, Ludwig-Maximilians-Universität München, München, Germany
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Zamani M, diCenzo GC, Milunovic B, Finan TM. A putative 3-hydroxyisobutyryl-CoA hydrolase is required for efficient symbiotic nitrogen fixation in Sinorhizobium meliloti and Sinorhizobium fredii NGR234. Environ Microbiol 2016; 19:218-236. [PMID: 27727485 DOI: 10.1111/1462-2920.13570] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 10/06/2016] [Indexed: 12/12/2022]
Abstract
We report that the smb20752 gene of the alfalfa symbiont Sinorhizobium meliloti is a novel symbiotic gene required for full N2 -fixation. Deletion of smb20752 resulted in lower nitrogenase activity and smaller nodules without impacting overall nodule morphology. Orthologs of smb20752 were present in all alpha and beta rhizobia, including the ngr_b20860 gene of Sinorhizobium fredii NGR234. A ngr_b20860 mutant formed Fix- determinate nodules that developed normally to a late stage of the symbiosis on the host plants Macroptilium atropurpureum and Vigna unguiculata. However an early symbiotic defect was evident during symbiosis with Leucaena leucocephala, producing Fix- indeterminate nodules. The smb20752 and ngr_b20860 genes encode putative 3-hydroxyisobutyryl-CoA (HIB-CoA) hydrolases. HIB-CoA hydrolases are required for l-valine catabolism and appear to prevent the accumulation of toxic metabolic intermediates, particularly methacrylyl-CoA. Evidence presented here and elsewhere (Curson et al., , PLoS ONE 9:e97660) demonstrated that Smb20752 and NGR_b20860 can also prevent metabolic toxicity, are required for l-valine metabolism, and play an undefined role in 3-hydroxybutyrate catabolism. We present evidence that the symbiotic defect of the HIB-CoA hydrolase mutants is independent of the inability to catabolize l-valine and suggest it relates to the toxicity resulting from metabolism of other compounds possibly related to 3-hydroxybutyric acid.
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Affiliation(s)
- Maryam Zamani
- Department of Biology, McMaster University, 1280 Main St. W., Hamilton, Ontario, Canada, L8S 4K1
| | - George C diCenzo
- Department of Biology, McMaster University, 1280 Main St. W., Hamilton, Ontario, Canada, L8S 4K1
| | - Branislava Milunovic
- Department of Biology, McMaster University, 1280 Main St. W., Hamilton, Ontario, Canada, L8S 4K1
| | - Turlough M Finan
- Department of Biology, McMaster University, 1280 Main St. W., Hamilton, Ontario, Canada, L8S 4K1
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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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Whole-Genome Sequence of Mesorhizobium hungaricum sp. nov. Strain UASWS1009, a Potential Resource for Agricultural and Environmental Uses. GENOME ANNOUNCEMENTS 2016; 4:4/5/e01158-16. [PMID: 27738050 PMCID: PMC5064123 DOI: 10.1128/genomea.01158-16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We report here the whole-genome shotgun sequences of the strain UASWS1009 of the species Mesorhizobium hungaricum sp. nov., which are different from any other known Mesorhizobium species. This is the first genome registered for this new species, which could be considered as a potential resource for agriculture and environmental uses.
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Whole-Genome Sequence of Bradyrhizobium elkanii Strain UASWS1016, a Potential Symbiotic Biofertilizer for Agriculture. GENOME ANNOUNCEMENTS 2016; 4:4/5/e01095-16. [PMID: 27795259 PMCID: PMC5054329 DOI: 10.1128/genomea.01095-16] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Bradyrhizobium elkanii UASWS1016 has been isolated from a wet oxidation sewage plant in Italy. Fully equipped for ammonia assimilation, heavy metal resistances, and aromatic compounds degradation, it carries a large type IV secretion system, specific of plant-associated microbes. Deprived of toxins, it could be considered for agricultural and environmental uses.
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