1
|
Acosta-Jurado S, Fuentes-Romero F, Ruiz-Sainz JE, Janczarek M, Vinardell JM. Rhizobial Exopolysaccharides: Genetic Regulation of Their Synthesis and Relevance in Symbiosis with Legumes. Int J Mol Sci 2021; 22:6233. [PMID: 34207734 PMCID: PMC8227245 DOI: 10.3390/ijms22126233] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 06/03/2021] [Accepted: 06/06/2021] [Indexed: 12/11/2022] Open
Abstract
Rhizobia are soil proteobacteria able to engage in a nitrogen-fixing symbiotic interaction with legumes that involves the rhizobial infection of roots and the bacterial invasion of new organs formed by the plant in response to the presence of appropriate bacterial partners. This interaction relies on a complex molecular dialogue between both symbionts. Bacterial N-acetyl-glucosamine oligomers called Nod factors are indispensable in most cases for early steps of the symbiotic interaction. In addition, different rhizobial surface polysaccharides, such as exopolysaccharides (EPS), may also be symbiotically relevant. EPS are acidic polysaccharides located out of the cell with little or no cell association that carry out important roles both in free-life and in symbiosis. EPS production is very complexly modulated and, frequently, co-regulated with Nod factors, but the type of co-regulation varies depending on the rhizobial strain. Many studies point out a signalling role for EPS-derived oligosaccharides in root infection and nodule invasion but, in certain symbiotic couples, EPS can be dispensable for a successful interaction. In summary, the complex regulation of the production of rhizobial EPS varies in different rhizobia, and the relevance of this polysaccharide in symbiosis with legumes depends on the specific interacting couple.
Collapse
Affiliation(s)
- Sebastián Acosta-Jurado
- Department of Microbiology, University of Sevilla, Avda. Reina Mercedes 6, 41012 Seville, Spain; (S.A.-J.); (F.F.-R.); (J.-E.R.-S.)
| | - Francisco Fuentes-Romero
- Department of Microbiology, University of Sevilla, Avda. Reina Mercedes 6, 41012 Seville, Spain; (S.A.-J.); (F.F.-R.); (J.-E.R.-S.)
| | - Jose-Enrique Ruiz-Sainz
- Department of Microbiology, University of Sevilla, Avda. Reina Mercedes 6, 41012 Seville, Spain; (S.A.-J.); (F.F.-R.); (J.-E.R.-S.)
| | - Monika Janczarek
- Department of Industrial and Environmental Microbiology, Institute of Biological Sciences, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland
| | - José-María Vinardell
- Department of Microbiology, University of Sevilla, Avda. Reina Mercedes 6, 41012 Seville, Spain; (S.A.-J.); (F.F.-R.); (J.-E.R.-S.)
| |
Collapse
|
2
|
Di Lorenzo F, Speciale I, Silipo A, Alías-Villegas C, Acosta-Jurado S, Rodríguez-Carvajal MÁ, Dardanelli MS, Palmigiano A, Garozzo D, Ruiz-Sainz JE, Molinaro A, Vinardell JM. Structure of the unusual Sinorhizobium fredii HH103 lipopolysaccharide and its role in symbiosis. J Biol Chem 2020; 295:10969-10987. [PMID: 32546484 PMCID: PMC7415993 DOI: 10.1074/jbc.ra120.013393] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 06/11/2020] [Indexed: 11/06/2022] Open
Abstract
Rhizobia are soil bacteria that form important symbiotic associations with legumes, and rhizobial surface polysaccharides, such as K-antigen polysaccharide (KPS) and lipopolysaccharide (LPS), might be important for symbiosis. Previously, we obtained a mutant of Sinorhizobium fredii HH103, rkpA, that does not produce KPS, a homopolysaccharide of a pseudaminic acid derivative, but whose LPS electrophoretic profile was indistinguishable from that of the WT strain. We also previously demonstrated that the HH103 rkpLMNOPQ operon is responsible for 5-acetamido-3,5,7,9-tetradeoxy-7-(3-hydroxybutyramido)-l-glycero-l-manno-nonulosonic acid [Pse5NAc7(3OHBu)] production and is involved in HH103 KPS and LPS biosynthesis and that an HH103 rkpM mutant cannot produce KPS and displays an altered LPS structure. Here, we analyzed the LPS structure of HH103 rkpA, focusing on the carbohydrate portion, and found that it contains a highly heterogeneous lipid A and a peculiar core oligosaccharide composed of an unusually high number of hexuronic acids containing β-configured Pse5NAc7(3OHBu). This pseudaminic acid derivative, in its α-configuration, was the only structural component of the S. fredii HH103 KPS and, to the best of our knowledge, has never been reported from any other rhizobial LPS. We also show that Pse5NAc7(3OHBu) is the complete or partial epitope for a mAb, NB6-228.22, that can recognize the HH103 LPS, but not those of most of the S. fredii strains tested here. We also show that the LPS from HH103 rkpM is identical to that of HH103 rkpA but devoid of any Pse5NAc7(3OHBu) residues. Notably, this rkpM mutant was severely impaired in symbiosis with its host, Macroptilium atropurpureum.
Collapse
Affiliation(s)
- Flaviana Di Lorenzo
- Department of Chemical Sciences, University of Naples Federico II, Napoli, Italy
| | - Immacolata Speciale
- Department of Chemical Sciences, University of Naples Federico II, Napoli, Italy
| | - Alba Silipo
- Department of Chemical Sciences, University of Naples Federico II, Napoli, Italy
| | | | | | | | - Marta S Dardanelli
- Departamento de Biología Molecular, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto-INBIAS, CONICET, Córdoba, Argentina
| | - Angelo Palmigiano
- Istituto per i Polimeri, Compositi e Biomateriali IPCB, Consiglio Nazionale delle Ricerche, Catania, Italy
| | - Domenico Garozzo
- Istituto per i Polimeri, Compositi e Biomateriali IPCB, Consiglio Nazionale delle Ricerche, Catania, Italy
| | | | - Antonio Molinaro
- Department of Chemical Sciences, University of Naples Federico II, Napoli, Italy
| | - José-María Vinardell
- Department of Microbiology, Faculty of Biology, University of Seville, Sevilla, Spain
| |
Collapse
|
3
|
Maillet F, Fournier J, Mendis HC, Tadege M, Wen J, Ratet P, Mysore KS, Gough C, Jones KM. Sinorhizobium meliloti succinylated high-molecular-weight succinoglycan and the Medicago truncatula LysM receptor-like kinase MtLYK10 participate independently in symbiotic infection. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 102:311-326. [PMID: 31782853 PMCID: PMC9327734 DOI: 10.1111/tpj.14625] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 11/08/2019] [Accepted: 11/19/2019] [Indexed: 05/12/2023]
Abstract
The formation of nitrogen-fixing nodules on legume hosts is a finely tuned process involving many components of both symbiotic partners. Production of the exopolysaccharide succinoglycan by the nitrogen-fixing bacterium Sinorhizobium meliloti 1021 is needed for an effective symbiosis with Medicago spp., and the succinyl modification to this polysaccharide is critical. However, it is not known when succinoglycan intervenes in the symbiotic process, and it is not known whether the plant lysin-motif receptor-like kinase MtLYK10 intervenes in recognition of succinoglycan, as might be inferred from work on the Lotus japonicus MtLYK10 ortholog, LjEPR3. We studied the symbiotic infection phenotypes of S. meliloti mutants deficient in succinoglycan production or producing modified succinoglycan, in wild-type Medicago truncatula plants and in Mtlyk10 mutant plants. On wild-type plants, S. meliloti strains producing no succinoglycan or only unsuccinylated succinoglycan still induced nodule primordia and epidermal infections, but further progression of the symbiotic process was blocked. These S. meliloti mutants induced a more severe infection phenotype on Mtlyk10 mutant plants. Nodulation by succinoglycan-defective strains was achieved by in trans rescue with a Nod factor-deficient S. meliloti mutant. While the Nod factor-deficient strain was always more abundant inside nodules, the succinoglycan-deficient strain was more efficient than the strain producing only unsuccinylated succinoglycan. Together, these data show that succinylated succinoglycan is essential for infection thread formation in M. truncatula, and that MtLYK10 plays an important, but different role in this symbiotic process. These data also suggest that succinoglycan is more important than Nod factors for bacterial survival inside nodules.
Collapse
Affiliation(s)
- Fabienne Maillet
- LIPMUniversité de Toulouse, INRA, CNRSCastanet‐TolosanCS 52627France
| | - Joëlle Fournier
- LIPMUniversité de Toulouse, INRA, CNRSCastanet‐TolosanCS 52627France
| | - Hajeewaka C. Mendis
- Department of Biological ScienceFlorida State UniversityTallahasseeFL32306USA
| | - Million Tadege
- Department of Plant and Soil SciencesInstitute for Agricultural BiosciencesOklahoma State UniversityArdmoreOK73401USA
| | - Jiangqi Wen
- Noble Research InstituteLLC.2510 Sam Noble ParkwayArdmoreOK73401USA
| | - Pascal Ratet
- IPS2Institute of Plant Sciences Paris-Saclay IPS2, CNRS, INRA, Université Paris-Sud, Université Evry, Université Paris-SaclayBâtiment 63091405OrsayFrance
- Institute of Plant Sciences Paris-Saclay IPS2, Paris Diderot, Sorbonne Paris-CitéBâtiment 63091405OrsayFrance
| | | | - Clare Gough
- LIPMUniversité de Toulouse, INRA, CNRSCastanet‐TolosanCS 52627France
| | - Kathryn M. Jones
- Department of Biological ScienceFlorida State UniversityTallahasseeFL32306USA
| |
Collapse
|
4
|
Lipa P, Vinardell JM, Janczarek M. Transcriptomic Studies Reveal that the Rhizobium leguminosarum Serine/Threonine Protein Phosphatase PssZ has a Role in the Synthesis of Cell-Surface Components, Nutrient Utilization, and Other Cellular Processes. Int J Mol Sci 2019; 20:ijms20122905. [PMID: 31197117 PMCID: PMC6628131 DOI: 10.3390/ijms20122905] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 06/10/2019] [Accepted: 06/11/2019] [Indexed: 02/07/2023] Open
Abstract
Rhizobium leguminosarum bv. trifolii is a soil bacterium capable of establishing symbiotic associations with clover plants (Trifolium spp.). Surface polysaccharides, transport systems, and extracellular components synthesized by this bacterium are required for both the adaptation to changing environmental conditions and successful infection of host plant roots. The pssZ gene located in the Pss-I region, which is involved in the synthesis of extracellular polysaccharide, encodes a protein belonging to the group of serine/threonine protein phosphatases. In this study, a comparative transcriptomic analysis of R. leguminosarum bv. trifolii wild-type strain Rt24.2 and its derivative Rt297 carrying a pssZ mutation was performed. RNA-Seq data identified a large number of genes differentially expressed in these two backgrounds. Transcriptome profiling of the pssZ mutant revealed a role of the PssZ protein in several cellular processes, including cell signalling, transcription regulation, synthesis of cell-surface polysaccharides and components, and bacterial metabolism. In addition, we show that inactivation of pssZ affects the rhizobial ability to grow in the presence of different sugars and at various temperatures, as well as the production of different surface polysaccharides. In conclusion, our results identified a set of genes whose expression was affected by PssZ and confirmed the important role of this protein in the rhizobial regulatory network.
Collapse
Affiliation(s)
- Paulina Lipa
- Department of Genetics and Microbiology, Institute of Microbiology and Biotechnology, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Akademicka 19 St., 20-033 Lublin, Poland.
| | - José-María Vinardell
- Department of Microbiology, Faculty of Biology, University of Sevilla, Avda. Reina Mercedes 6, 41012 Sevilla, Spain.
| | - Monika Janczarek
- Department of Genetics and Microbiology, Institute of Microbiology and Biotechnology, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Akademicka 19 St., 20-033 Lublin, Poland.
| |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
Mutation in the pssZ Gene Negatively Impacts Exopolysaccharide Synthesis, Surface Properties, and Symbiosis of Rhizobium leguminosarum bv. trifolii with Clover. Genes (Basel) 2018; 9:genes9070369. [PMID: 30041474 PMCID: PMC6071215 DOI: 10.3390/genes9070369] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 07/05/2018] [Accepted: 07/16/2018] [Indexed: 12/19/2022] Open
Abstract
Rhizobium leguminosarum bv. trifolii is a soil bacterium capable of establishing a nitrogen-fixing symbiosis with clover plants (Trifolium spp.). This bacterium secretes large amounts of acidic exopolysaccharide (EPS), which plays an essential role in the symbiotic interaction with the host plant. This polymer is biosynthesized by a multi-enzymatic complex located in the bacterial inner membrane, whose components are encoded by a large chromosomal gene cluster, called Pss-I. In this study, we characterize R. leguminosarum bv. trifolii strain Rt297 that harbors a Tn5 transposon insertion located in the pssZ gene from the Pss-I region. This gene codes for a protein that shares high identity with bacterial serine/threonine protein phosphatases. We demonstrated that the pssZ mutation causes pleiotropic effects in rhizobial cells. Strain Rt297 exhibited several physiological and symbiotic defects, such as lack of EPS production, reduced growth kinetics and motility, altered cell-surface properties, and failure to infect the host plant. These data indicate that the protein encoded by the pssZ gene is indispensable for EPS synthesis, but also required for proper functioning of R. leguminosarum bv. trifolii cells.
Collapse
|
7
|
Kopycińska M, Lipa P, Cieśla J, Kozieł M, Janczarek M. Extracellular polysaccharide protects Rhizobium leguminosarum cells against zinc stress in vitro and during symbiosis with clover. ENVIRONMENTAL MICROBIOLOGY REPORTS 2018; 10:355-368. [PMID: 29633524 DOI: 10.1111/1758-2229.12646] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 03/27/2018] [Accepted: 03/27/2018] [Indexed: 06/08/2023]
Abstract
Rhizobium leguminosarum bv. trifolii is a soil bacterium that establishes symbiosis with clover (Trifolium spp.) under nitrogen-limited conditions. This microorganism produces exopolysaccharide (EPS), which plays an important role in symbiotic interactions with the host plant. The aim of the current study was to establish the role of EPS in the response of R. leguminosarum bv. trifolii cells, free-living and during symbiosis, to zinc stress. We show that EPS-deficient mutants were more sensitive to Zn2+ exposure than EPS-producing strains, and that EPS overexpression conferred some protection onto the strains beyond that observed in the wild type. Exposure of the bacteria to Zn2+ ions stimulated EPS and biofilm production, and increased cell hydrophobicity. However, zinc stress negatively affected the motility and attachment of bacteria to clover roots, as well as the symbiosis with the host plant. In the presence of Zn2+ ions, cell viability, root attachment, biofilm formation and symbiotic efficiency of EPS-overproducing strains were significantly higher than those of the EPS-deficient mutants. We conclude that EPS plays an important role in the adaptation of rhizobia to zinc stress, in both the free-living stage and during symbiosis.
Collapse
Affiliation(s)
- Magdalena Kopycińska
- Department of Genetics and Microbiology, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland
| | - Paulina Lipa
- Department of Genetics and Microbiology, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland
| | - Jolanta Cieśla
- Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4, 20-290, Lublin, Poland
| | - Marta Kozieł
- Department of Genetics and Microbiology, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland
| | - Monika Janczarek
- Department of Genetics and Microbiology, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland
| |
Collapse
|
8
|
Acosta-Jurado S, Rodríguez-Navarro DN, Kawaharada Y, Perea JF, Gil-Serrano A, Jin H, An Q, Rodríguez-Carvajal MA, Andersen SU, Sandal N, Stougaard J, Vinardell JM, Ruiz-Sainz JE. Sinorhizobium fredii HH103 Invades Lotus burttii by Crack Entry in a Nod Factor-and Surface Polysaccharide-Dependent Manner. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2016; 29:925-937. [PMID: 27827003 DOI: 10.1094/mpmi-09-16-0195-r] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Sinorhizobium fredii HH103-Rifr, a broad host range rhizobial strain, induces nitrogen-fixing nodules in Lotus burttii but ineffective nodules in L. japonicus. Confocal microscopy studies showed that Mesorhizobium loti MAFF303099 and S. fredii HH103-Rifr invade L. burttii roots through infection threads or epidermal cracks, respectively. Infection threads in root hairs were not observed in L. burttii plants inoculated with S. fredii HH103-Rifr. A S. fredii HH103-Rifr nodA mutant failed to nodulate L. burttii, demonstrating that Nod factors are strictly necessary for this crack-entry mode, and a noeL mutant was also severely impaired in L. burttii nodulation, indicating that the presence of fucosyl residues in the Nod factor is symbiotically relevant. However, significant symbiotic impacts due to the absence of methylation or to acetylation of the fucosyl residue were not detected. In contrast S. fredii HH103-Rifr mutants showing lipopolysaccharide alterations had reduced symbiotic capacity, while mutants affected in production of either exopolysaccharides, capsular polysaccharides, or both were not impaired in nodulation. Mutants unable to produce cyclic glucans and purine or pyrimidine auxotrophic mutants formed ineffective nodules with L. burttii. Flagellin-dependent bacterial mobility was not required for crack infection, since HH103-Rifr fla mutants nodulated L. burttii. None of the S. fredii HH103-Rifr surface-polysaccharide mutants gained effective nodulation with L. japonicus.
Collapse
Affiliation(s)
- Sebastián Acosta-Jurado
- 1 Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, C.P. 41012, Sevilla, Spain
| | | | - Yasuyuki Kawaharada
- 3 Department of Molecular Biology and Genetics, Centre for Carbohydrate Recognition and Signalling, Aarhus University, Gustav Wieds Vej 10, Aarhus C DK-8000, Denmark; and
| | - Juan Fernández Perea
- 2 IFAPA, Centro Las Torres-Tomejil, Apartado Oficial 41200, Alcalá del Río, Sevilla, Spain
| | - Antonio Gil-Serrano
- 4 Departamento de Química Orgánica, Facultad de Química, Universidad de Sevilla, Calle Profesor García González 1, C. P. 41012, Sevilla, Spain
| | - Haojie Jin
- 3 Department of Molecular Biology and Genetics, Centre for Carbohydrate Recognition and Signalling, Aarhus University, Gustav Wieds Vej 10, Aarhus C DK-8000, Denmark; and
| | - Qi An
- 1 Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, C.P. 41012, Sevilla, Spain
| | - Miguel A Rodríguez-Carvajal
- 4 Departamento de Química Orgánica, Facultad de Química, Universidad de Sevilla, Calle Profesor García González 1, C. P. 41012, Sevilla, Spain
| | - Stig U Andersen
- 3 Department of Molecular Biology and Genetics, Centre for Carbohydrate Recognition and Signalling, Aarhus University, Gustav Wieds Vej 10, Aarhus C DK-8000, Denmark; and
| | - Niels Sandal
- 3 Department of Molecular Biology and Genetics, Centre for Carbohydrate Recognition and Signalling, Aarhus University, Gustav Wieds Vej 10, Aarhus C DK-8000, Denmark; and
| | - Jens Stougaard
- 3 Department of Molecular Biology and Genetics, Centre for Carbohydrate Recognition and Signalling, Aarhus University, Gustav Wieds Vej 10, Aarhus C DK-8000, Denmark; and
| | - José-María Vinardell
- 1 Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, C.P. 41012, Sevilla, Spain
| | - José E Ruiz-Sainz
- 1 Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, C.P. 41012, Sevilla, Spain
| |
Collapse
|
9
|
Surface Properties of Wild-Type Rhizobium leguminosarum bv. trifolii Strain 24.2 and Its Derivatives with Different Extracellular Polysaccharide Content. PLoS One 2016; 11:e0165080. [PMID: 27760230 PMCID: PMC5070845 DOI: 10.1371/journal.pone.0165080] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 10/05/2016] [Indexed: 11/19/2022] Open
Abstract
Rhizobium leguminosarum bv. trifolii is a soil bacterium able to establish symbiosis with agriculturally important legumes, i.e., clover plants (Trifolium spp.). Cell surface properties of rhizobia play an essential role in their interaction with both biotic and abiotic surfaces. Physicochemical properties of bacterial cells are underpinned by the chemical composition of their envelope surrounding the cells, and depend on various environmental conditions. In this study, we performed a comprehensive characterization of cell surface properties of a wild-type R. leguminosarum bv. trifolii strain 24.2 and its derivatives producing various levels of exopolysaccharide (EPS), namely, pssA mutant Rt5819 deficient in EPS synthesis, rosR mutant Rt2472 producing diminished amounts of this polysaccharide, and two EPS-overproducing strains, Rt24.2(pBA1) and Rt24.2(pBR1), under different growth conditions (medium type, bacterial culture age, cell viability, and pH). We established that EPS plays an essential role in the electrophoretic mobility of rhizobial cells, and that higher amounts of EPS produced resulted in greater negative electrophoretic mobility and higher acidity (lower pKapp,av) of the bacterial cell surface. From the tested strains, the electrophoretic mobility was lowest in EPS-deficient pssA mutant. Moreover, EPS produced by rhizobial strains resulted not only in an increase of negative surface charge but also in increased hydrophobicity of bacterial cell surface. This was determined by measurements of water contact angle, surface free energy, and free energy of bacterial surface-water-bacterial surface interaction. Electrophoretic mobility of the studied strains was also affected by the structure of the bacterial population (i.e., live/dead cell ratio), medium composition (ionic strength and mono- and divalent cation concentrations), and pH.
Collapse
|
10
|
Rachwał K, Boguszewska A, Kopcińska J, Karaś M, Tchórzewski M, Janczarek M. The Regulatory Protein RosR Affects Rhizobium leguminosarum bv. trifolii Protein Profiles, Cell Surface Properties, and Symbiosis with Clover. Front Microbiol 2016; 7:1302. [PMID: 27602024 PMCID: PMC4993760 DOI: 10.3389/fmicb.2016.01302] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 08/08/2016] [Indexed: 11/13/2022] Open
Abstract
Rhizobium leguminosarum bv. trifolii is capable of establishing a symbiotic relationship with plants from the genus Trifolium. Previously, a regulatory protein encoded by rosR was identified and characterized in this bacterium. RosR possesses a Cys2-His2-type zinc finger motif and belongs to Ros/MucR family of rhizobial transcriptional regulators. Transcriptome profiling of the rosR mutant revealed a role of this protein in several cellular processes, including the synthesis of cell-surface components and polysaccharides, motility, and bacterial metabolism. Here, we show that a mutation in rosR resulted in considerable changes in R. leguminosarum bv. trifolii protein profiles. Extracellular, membrane, and periplasmic protein profiles of R. leguminosarum bv. trifolii wild type and the rosR mutant were examined, and proteins with substantially different abundances between these strains were identified. Compared with the wild type, extracellular fraction of the rosR mutant contained greater amounts of several proteins, including Ca(2+)-binding cadherin-like proteins, a RTX-like protein, autoaggregation protein RapA1, and flagellins FlaA and FlaB. In contrast, several proteins involved in the uptake of various substrates were less abundant in the mutant strain (DppA, BraC, and SfuA). In addition, differences were observed in membrane proteins of the mutant and wild-type strains, which mainly concerned various transport system components. Using atomic force microscopy (AFM) imaging, we characterized the topography and surface properties of the rosR mutant and wild-type cells. We found that the mutation in rosR gene also affected surface properties of R. leguminosarum bv. trifolii. The mutant cells were significantly more hydrophobic than the wild-type cells, and their outer membrane was three times more permeable to the hydrophobic dye N-phenyl-1-naphthylamine. The mutation of rosR also caused defects in bacterial symbiotic interaction with clover plants. Compared with the wild type, the rosR mutant infected host plant roots much less effectively and its nodule occupation was disturbed. At the ultrastructural level, the most striking differences between the mutant and the wild-type nodules concerned the structure of infection threads, release of bacteria, and bacteroid differentiation. This confirms an essential role of RosR in establishment of successful symbiotic interaction of R. leguminosarum bv. trifolii with clover plants.
Collapse
Affiliation(s)
- Kamila Rachwał
- Department of Genetics and Microbiology, Institute of Microbiology and Biotechnology, Maria Curie-Skłodowska University Lublin, Poland
| | - Aleksandra Boguszewska
- Department of Molecular Biology, Institute of Microbiology and Biotechnology, Maria Curie-Skłodowska University Lublin, Poland
| | - Joanna Kopcińska
- Department of Botany, Faculty of Agriculture and Biology, Warsaw University of Life Sciences Warsaw, Poland
| | - Magdalena Karaś
- Department of Genetics and Microbiology, Institute of Microbiology and Biotechnology, Maria Curie-Skłodowska University Lublin, Poland
| | - Marek Tchórzewski
- Department of Molecular Biology, Institute of Microbiology and Biotechnology, Maria Curie-Skłodowska University Lublin, Poland
| | - Monika Janczarek
- Department of Genetics and Microbiology, Institute of Microbiology and Biotechnology, Maria Curie-Skłodowska University Lublin, Poland
| |
Collapse
|
11
|
Acosta-Jurado S, Navarro-Gómez P, Murdoch PDS, Crespo-Rivas JC, Jie S, Cuesta-Berrio L, Ruiz-Sainz JE, Rodríguez-Carvajal MÁ, Vinardell JM. Exopolysaccharide Production by Sinorhizobium fredii HH103 Is Repressed by Genistein in a NodD1-Dependent Manner. PLoS One 2016; 11:e0160499. [PMID: 27486751 PMCID: PMC4972438 DOI: 10.1371/journal.pone.0160499] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 07/20/2016] [Indexed: 11/21/2022] Open
Abstract
In the rhizobia-legume symbiotic interaction, bacterial surface polysaccharides, such as exopolysaccharide (EPS), lipopolysaccharide (LPS), K-antigen polysaccharide (KPS) or cyclic glucans (CG), appear to play crucial roles either acting as signals required for the progression of the interaction and/or preventing host defence mechanisms. The symbiotic significance of each of these polysaccharides varies depending on the specific rhizobia-legume couple. In this work we show that the production of exopolysaccharide by Sinorhizobium fredii HH103, but not by other S. fredii strains such as USDA257 or NGR234, is repressed by nod gene inducing flavonoids such as genistein and that this repression is dependent on the presence of a functional NodD1 protein. In agreement with the importance of EPS for bacterial biofilms, this reduced EPS production upon treatment with flavonoids correlates with decreased biofilm formation ability. By using quantitative RT-PCR analysis we show that expression of the exoY2 and exoK genes is repressed in late stationary cultures of S. fredii HH103 upon treatment with genistein. Results presented in this work show that in S. fredii HH103 EPS production is regulated just in the opposite way than other bacterial signals such as Nod factors and type 3 secreted effectors: it is repressed by flavonoids and NodD1 and enhanced by the nod repressor NolR. These results are in agreement with our previous observations showing that lack of EPS production by S. fredii HH103 is not only non-detrimental but even beneficial for symbiosis with soybean.
Collapse
Affiliation(s)
| | - Pilar Navarro-Gómez
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
| | - Piedad del Socorro Murdoch
- Departamento de Bioquímica Vegetal y Biología Molecular, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
| | | | - Shi Jie
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
| | - Lidia Cuesta-Berrio
- Departamento of Química Orgánica, Facultad de Química, Universidad de Sevilla, Sevilla, Spain
| | | | | | - José-María Vinardell
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
- * E-mail:
| |
Collapse
|
12
|
López-Baena FJ, Ruiz-Sainz JE, Rodríguez-Carvajal MA, Vinardell JM. Bacterial Molecular Signals in the Sinorhizobium fredii-Soybean Symbiosis. Int J Mol Sci 2016; 17:E755. [PMID: 27213334 PMCID: PMC4881576 DOI: 10.3390/ijms17050755] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 05/04/2016] [Accepted: 05/05/2016] [Indexed: 12/20/2022] Open
Abstract
Sinorhizobium (Ensifer) fredii (S. fredii) is a rhizobial species exhibiting a remarkably broad nodulation host-range. Thus, S. fredii is able to effectively nodulate dozens of different legumes, including plants forming determinate nodules, such as the important crops soybean and cowpea, and plants forming indeterminate nodules, such as Glycyrrhiza uralensis and pigeon-pea. This capacity of adaptation to different symbioses makes the study of the molecular signals produced by S. fredii strains of increasing interest since it allows the analysis of their symbiotic role in different types of nodule. In this review, we analyze in depth different S. fredii molecules that act as signals in symbiosis, including nodulation factors, different surface polysaccharides (exopolysaccharides, lipopolysaccharides, cyclic glucans, and K-antigen capsular polysaccharides), and effectors delivered to the interior of the host cells through a symbiotic type 3 secretion system.
Collapse
Affiliation(s)
- Francisco J López-Baena
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avenida de Reina Mercedes, 6, 41012 Sevilla, Spain.
| | - José E Ruiz-Sainz
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avenida de Reina Mercedes, 6, 41012 Sevilla, Spain.
| | - Miguel A Rodríguez-Carvajal
- Departamento de Química Orgánica, Facultad de Química, Universidad de Sevilla, Profesor García González, 1, 41012 Sevilla, Spain.
| | - José M Vinardell
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avenida de Reina Mercedes, 6, 41012 Sevilla, Spain.
| |
Collapse
|
13
|
Crespo-Rivas JC, Guefrachi I, Mok KC, Villaécija-Aguilar JA, Acosta-Jurado S, Pierre O, Ruiz-Sainz JE, Taga ME, Mergaert P, Vinardell JM. Sinorhizobium fredii HH103 bacteroids are not terminally differentiated and show altered O-antigen in nodules of the Inverted Repeat-Lacking Clade legume Glycyrrhiza uralensis. Environ Microbiol 2015; 18:2392-404. [PMID: 26521863 DOI: 10.1111/1462-2920.13101] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 10/20/2015] [Indexed: 11/28/2022]
Abstract
In rhizobial species that nodulate inverted repeat-lacking clade (IRLC) legumes, such as the interaction between Sinorhizobium meliloti and Medicago, bacteroid differentiation is driven by an endoreduplication event that is induced by host nodule-specific cysteine rich (NCR) antimicrobial peptides and requires the participation of the bacterial protein BacA. We have studied bacteroid differentiation of Sinorhizobium fredii HH103 in three host plants: Glycine max, Cajanus cajan and the IRLC legume Glycyrrhiza uralensis. Flow cytometry, microscopy analyses and viability studies of bacteroids as well as confocal microscopy studies carried out in nodules showed that S. fredii HH103 bacteroids, regardless of the host plant, had deoxyribonucleic acid (DNA) contents, cellular sizes and survival rates similar to those of free-living bacteria. Contrary to S. meliloti, S. fredii HH103 showed little or no sensitivity to Medicago NCR247 and NCR335 peptides. Inactivation of S. fredii HH103 bacA neither affected symbiosis with Glycyrrhiza nor increased bacterial sensitivity to Medicago NCRs. Finally, HH103 bacteroids isolated from Glycyrrhiza, but not those isolated from Cajanus or Glycine, showed an altered lipopolysaccharide. Our studies indicate that, in contrast to the S. meliloti-Medicago model symbiosis, bacteroids in the S. fredii HH103-Glycyrrhiza symbiosis do not undergo NCR-induced and bacA-dependent terminal differentiation.
Collapse
Affiliation(s)
- Juan C Crespo-Rivas
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, CP, 41012, Sevilla, Spain
| | - Ibtissem Guefrachi
- Institute for Integrative Biology of the Cell, Centre National de la Recherche Scientifique, UMR 9198, 91198, Gif-sur-Yvette, France
| | - Kenny C Mok
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
| | - José A Villaécija-Aguilar
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, CP, 41012, Sevilla, Spain.,Institute for Integrative Biology of the Cell, Centre National de la Recherche Scientifique, UMR 9198, 91198, Gif-sur-Yvette, France
| | - Sebastián Acosta-Jurado
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, CP, 41012, Sevilla, Spain
| | - Olivier Pierre
- Institute for Integrative Biology of the Cell, Centre National de la Recherche Scientifique, UMR 9198, 91198, Gif-sur-Yvette, France
| | - José E Ruiz-Sainz
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, CP, 41012, Sevilla, Spain
| | - Michiko E Taga
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
| | - Peter Mergaert
- Institute for Integrative Biology of the Cell, Centre National de la Recherche Scientifique, UMR 9198, 91198, Gif-sur-Yvette, France
| | - José M Vinardell
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, CP, 41012, Sevilla, Spain
| |
Collapse
|
14
|
Vinardell JM, Acosta-Jurado S, Zehner S, Göttfert M, Becker A, Baena I, Blom J, Crespo-Rivas JC, Goesmann A, Jaenicke S, Krol E, McIntosh M, Margaret I, Pérez-Montaño F, Schneiker-Bekel S, Serranía J, Szczepanowski R, Buendía AM, Lloret J, Bonilla I, Pühler A, Ruiz-Sainz JE, Weidner S. The Sinorhizobium fredii HH103 Genome: A Comparative Analysis With S. fredii Strains Differing in Their Symbiotic Behavior With Soybean. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2015; 28:811-24. [PMID: 25675256 DOI: 10.1094/mpmi-12-14-0397-fi] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Sinorhizobium fredii HH103 is a fast-growing rhizobial strain infecting a broad range of legumes including both American and Asiatic soybeans. In this work, we present the sequencing and annotation of the HH103 genome (7.25 Mb), consisting of one chromosome and six plasmids and representing the structurally most complex sinorhizobial genome sequenced so far. Comparative genomic analyses of S. fredii HH103 with strains USDA257 and NGR234 showed that the core genome of these three strains contains 4,212 genes (61.7% of the HH103 genes). Synteny plot analysis revealed that the much larger chromosome of USDA257 (6.48 Mb) is colinear to the HH103 (4.3 Mb) and NGR324 chromosomes (3.9 Mb). An additional region of the USDA257 chromosome of about 2 Mb displays similarity to plasmid pSfHH103e. Remarkable differences exist between HH103 and NGR234 concerning nod genes, flavonoid effect on surface polysaccharide production, and quorum-sensing systems. Furthermore a number of protein secretion systems have been found. Two genes coding for putative type III-secreted effectors not previously described in S. fredii, nopI and gunA, have been located on the HH103 genome. These differences could be important to understand the different symbiotic behavior of S. fredii strains HH103, USDA257, and NGR234 with soybean.
Collapse
Affiliation(s)
- José-María Vinardell
- 1 Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla. Avda. Reina Mercedes 6, C.P. 41012 Sevilla, Spain
| | - Sebastián Acosta-Jurado
- 1 Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla. Avda. Reina Mercedes 6, C.P. 41012 Sevilla, Spain
| | - Susanne Zehner
- 2 Technische Universität Dresden, Institut für Genetik, Helmholtzstrasse 10, 01062 Dresden, Germany
| | - Michael Göttfert
- 2 Technische Universität Dresden, Institut für Genetik, Helmholtzstrasse 10, 01062 Dresden, Germany
| | - Anke Becker
- 3 LOEWE Center for Synthetic Microbiology (SYNMIKRO) and Faculty of Biology, Philipps-Universität Marburg, Hans-Meerwein-Str. 6, 35043 Marburg, Germany
| | - Irene Baena
- 4 Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Darwin 2, 28049-Madrid, Spain
| | - Jochem Blom
- 5 Centrum für Biotechnologie (CeBiTec), Universität Bielefeld, Universitaetsstr. 27, 33615 Bielefeld, Germany
| | - Juan Carlos Crespo-Rivas
- 1 Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla. Avda. Reina Mercedes 6, C.P. 41012 Sevilla, Spain
| | - Alexander Goesmann
- 5 Centrum für Biotechnologie (CeBiTec), Universität Bielefeld, Universitaetsstr. 27, 33615 Bielefeld, Germany
| | - Sebastian Jaenicke
- 5 Centrum für Biotechnologie (CeBiTec), Universität Bielefeld, Universitaetsstr. 27, 33615 Bielefeld, Germany
| | - Elizaveta Krol
- 3 LOEWE Center for Synthetic Microbiology (SYNMIKRO) and Faculty of Biology, Philipps-Universität Marburg, Hans-Meerwein-Str. 6, 35043 Marburg, Germany
| | - Matthew McIntosh
- 3 LOEWE Center for Synthetic Microbiology (SYNMIKRO) and Faculty of Biology, Philipps-Universität Marburg, Hans-Meerwein-Str. 6, 35043 Marburg, Germany
| | - Isabel Margaret
- 1 Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla. Avda. Reina Mercedes 6, C.P. 41012 Sevilla, Spain
| | - Francisco Pérez-Montaño
- 1 Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla. Avda. Reina Mercedes 6, C.P. 41012 Sevilla, Spain
| | - Susanne Schneiker-Bekel
- 5 Centrum für Biotechnologie (CeBiTec), Universität Bielefeld, Universitaetsstr. 27, 33615 Bielefeld, Germany
| | - Javier Serranía
- 3 LOEWE Center for Synthetic Microbiology (SYNMIKRO) and Faculty of Biology, Philipps-Universität Marburg, Hans-Meerwein-Str. 6, 35043 Marburg, Germany
| | - Rafael Szczepanowski
- 5 Centrum für Biotechnologie (CeBiTec), Universität Bielefeld, Universitaetsstr. 27, 33615 Bielefeld, Germany
| | - Ana-María Buendía
- 1 Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla. Avda. Reina Mercedes 6, C.P. 41012 Sevilla, Spain
| | - Javier Lloret
- 4 Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Darwin 2, 28049-Madrid, Spain
| | - Ildefonso Bonilla
- 4 Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Darwin 2, 28049-Madrid, Spain
| | - Alfred Pühler
- 5 Centrum für Biotechnologie (CeBiTec), Universität Bielefeld, Universitaetsstr. 27, 33615 Bielefeld, Germany
| | - José-Enrique Ruiz-Sainz
- 1 Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla. Avda. Reina Mercedes 6, C.P. 41012 Sevilla, Spain
| | - Stefan Weidner
- 5 Centrum für Biotechnologie (CeBiTec), Universität Bielefeld, Universitaetsstr. 27, 33615 Bielefeld, Germany
| |
Collapse
|
15
|
Rodríguez-Navarro DN, Rodríguez-Carvajal MA, Acosta-Jurado S, Soto MJ, Margaret I, Crespo-Rivas JC, Sanjuan J, Temprano F, Gil-Serrano A, Ruiz-Sainz JE, Vinardell JM. Structure and biological roles of Sinorhizobium fredii HH103 exopolysaccharide. PLoS One 2014; 9:e115391. [PMID: 25521500 PMCID: PMC4270759 DOI: 10.1371/journal.pone.0115391] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 11/21/2014] [Indexed: 11/25/2022] Open
Abstract
Here we report that the structure of the Sinorhizobium fredii HH103 exopolysaccharide (EPS) is composed of glucose, galactose, glucuronic acid, pyruvic acid, in the ratios 5∶2∶2∶1 and is partially acetylated. A S. fredii HH103 exoA mutant (SVQ530), unable to produce EPS, not only forms nitrogen fixing nodules with soybean but also shows increased competitive capacity for nodule occupancy. Mutant SVQ530 is, however, less competitive to nodulate Vigna unguiculata. Biofilm formation was reduced in mutant SVQ530 but increased in an EPS overproducing mutant. Mutant SVQ530 was impaired in surface motility and showed higher osmosensitivity compared to its wild type strain in media containing 50 mM NaCl or 5% (w/v) sucrose. Neither S. fredii HH103 nor 41 other S. fredii strains were recognized by soybean lectin (SBL). S. fredii HH103 mutants affected in exopolysaccharides (EPS), lipopolysaccharides (LPS), cyclic glucans (CG) or capsular polysaccharides (KPS) were not significantly impaired in their soybean-root attachment capacity, suggesting that these surface polysaccharides might not be relevant in early attachment to soybean roots. These results also indicate that the molecular mechanisms involved in S. fredii attachment to soybean roots might be different to those operating in Bradyrhizobium japonicum.
Collapse
Affiliation(s)
| | | | | | - María J Soto
- Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, Granada, Spain
| | - Isabel Margaret
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
| | - Juan C Crespo-Rivas
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
| | - Juan Sanjuan
- Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, Granada, Spain
| | - Francisco Temprano
- IFAPA, Centro las Torres-Tomejil, Apartado Oficial 41200, Alcalá del Río, (Sevilla), Spain
| | - Antonio Gil-Serrano
- Departamento de Química Orgánica, Facultad de Química, Universidad de Sevilla, Sevilla, Spain
| | - José E Ruiz-Sainz
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
| | - José M Vinardell
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
| |
Collapse
|
16
|
Margaret I, Lucas MM, Acosta-Jurado S, Buendía-Clavería AM, Fedorova E, Hidalgo Á, Rodríguez-Carvajal MA, Rodriguez-Navarro DN, Ruiz-Sainz JE, Vinardell JM. The Sinorhizobium fredii HH103 lipopolysaccharide is not only relevant at early soybean nodulation stages but also for symbiosome stability in mature nodules. PLoS One 2013; 8:e74717. [PMID: 24098345 PMCID: PMC3788101 DOI: 10.1371/journal.pone.0074717] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 08/04/2013] [Indexed: 11/25/2022] Open
Abstract
In this work we have characterised the Sinorhizobium fredii HH103 greA lpsB lpsCDE genetic region and analysed for the first time the symbiotic performance of Sinorhizobium fredii lps mutants on soybean. The organization of the S. fredii HH103 greA, lpsB, and lpsCDE genes was equal to that of Sinorhizobium meliloti 1021. S. fredii HH103 greA, lpsB, and lpsE mutant derivatives produced altered LPS profiles that were characteristic of the gene mutated. In addition, S. fredii HH103 greA mutants showed a reduction in bacterial mobility and an increase of auto-agglutination in liquid cultures. RT-PCR and qPCR experiments demonstrated that the HH103 greA gene has a positive effect on the transcription of lpsB. Soybean plants inoculated with HH103 greA, lpsB or lpsE mutants formed numerous ineffective pseudonodules and showed severe symptoms of nitrogen starvation. However, HH103 greA and lps mutants were also able to induce the formation of a reduced number of soybean nodules of normal external morphology, allowing the possibility of studying the importance of bacterial LPS in later stages of the S. fredii HH103-soybean symbiosis. The infected cells of these nodules showed signs of early termination of symbiosis and lytical clearance of bacteroids. These cells also had very thick walls and accumulation of phenolic-like compounds, pointing to induced defense reactions. Our results show the importance of bacterial LPS in later stages of the S. fredii HH103-soybean symbiosis and their role in preventing host cell defense reactions. S. fredii HH103 lpsB mutants also showed reduced nodulation with Vigna unguiculata, although the symbiotic impairment was less pronounced than in soybean.
Collapse
Affiliation(s)
- Isabel Margaret
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla. Sevilla, Spain
| | | | | | | | | | - Ángeles Hidalgo
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla. Sevilla, Spain
| | | | | | - José E. Ruiz-Sainz
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla. Sevilla, Spain
| | - José M. Vinardell
- Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla. Sevilla, Spain
| |
Collapse
|
17
|
Fast induction of biosynthetic polysaccharide genes lpxA, lpxE, and rkpI of Rhizobium sp. strain PRF 81 by common bean seed exudates is indicative of a key role in symbiosis. Funct Integr Genomics 2013; 13:275-83. [PMID: 23652766 DOI: 10.1007/s10142-013-0322-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 02/15/2013] [Accepted: 04/01/2013] [Indexed: 01/23/2023]
Abstract
Rhizobial surface polysaccharides (SPS) are, together with nodulation (Nod) factors, recognized as key molecules for establishment of rhizobia-legume symbiosis. In Rhizobium tropici, an important nitrogen-fixing symbiont of common bean (Phaseolus vulgaris L.), molecular structures and symbiotic roles of the SPS are poorly understood. In this study, Rhizobium sp. strain PRF 81 genes, belonging to the R. tropici group, were investigated: lpxA and lpxE, involved in biosynthesis and modification of the lipid-A anchor of lipopolysaccharide (LPS), and rkpI, involved in synthesis of a lipid carrier required for production of capsular polysaccharides (KPS). Reverse transcription quantitative PCR (RT-qPCR) analysis revealed, for the first time, that inducers released from common bean seeds strongly stimulated expression of all three SPS genes. When PRF 81 cells were grown for 48 h in the presence of seed exudates, twofold increases (p < 0.05) in the transcription levels of lpxE, lpxA, and rkpI genes were observed. However, higher increases (p < 0.05) in transcription rates, about 50-fold for lpxE and about 30-fold for lpxA and rkpI, were observed after only 5 min of incubation with common bean seed exudates. Evolutionary analyses revealed that lpxA and lpxE of PRF81 and of the type strain of R. tropici CIAT899(T)clustered with orthologous Rhizobium radiobacter and were more related to R. etli and Rhizobium leguminosarum, while rkpI was closer to the Sinorhizobium sp. group. Upregulation of lpxE, lpxA, and rkpI genes suggests that seed exudates can modulate production of SPS of Rhizobium sp. PRF81, leading to cell wall changes necessary for symbiosis establishment.
Collapse
|
18
|
Margaret I, Crespo-Rivas JC, Acosta-Jurado S, Buendía-Clavería AM, Cubo MT, Gil-Serrano A, Moreno J, Murdoch PS, Rodríguez-Carvajal MA, Rodríguez-Navarro DN, Ruiz-Sainz JE, Sanjuán J, Soto MJ, Vinardell JM. Sinorhizobium fredii HH103 rkp-3 genes are required for K-antigen polysaccharide biosynthesis, affect lipopolysaccharide structure and are essential for infection of legumes forming determinate nodules. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2012; 25:825-38. [PMID: 22397406 DOI: 10.1094/mpmi-10-11-0262] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The Sinorhizobium fredii HH103 rkp-3 region has been isolated and sequenced. Based on the similarities between the S. fredii HH103 rkpL, rkpM, rkpN, rkpO, rkpP, and rkpQ genes and their corresponding orthologues in Helicobacter pylori, we propose a possible pathway for the biosynthesis of the S. fredii HH103 K-antigen polysaccharide (KPS) repeating unit. Three rkp-3 genes (rkpM, rkpP, and rkpQ) involved in the biosynthesis of the HH103 KPS repeating unit (a derivative of the pseudaminic acid) have been mutated and analyzed. All the rkp-3 mutants failed to produce KPS and their lipopolysaccharide (LPS) profiles were altered. These mutants showed reduced motility and auto-agglutinated when early-stationary cultures were further incubated under static conditions. Glycine max, Vigna unguiculata (determinate nodule-forming legumes), and Cajanus cajan (indeterminate nodules) plants inoculated with mutants in rkpM, rkpQ, or rkpP only formed pseudonodules that did not fix nitrogen and were devoid of bacteria. In contrast, another indeterminate nodule-forming legume, Glycyrrhiza uralensis, was still able to form some nitrogen-fixing nodules with the three S. fredii HH103 rifampicin-resistant rkp-3 mutants tested. Our results suggest that the severe symbiotic impairment of the S. fredii rkp-3 mutants with soybean, V. unguiculata, and C. cajan is mainly due to the LPS alterations rather than to the incapacity to produce KPS.
Collapse
Affiliation(s)
- Isabel Margaret
- Departamento de Microbiología, Faculdad de Biología, Universidad de Sevilla, Sevilla, Spain
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Janczarek M. Environmental signals and regulatory pathways that influence exopolysaccharide production in rhizobia. Int J Mol Sci 2011; 12:7898-933. [PMID: 22174640 PMCID: PMC3233446 DOI: 10.3390/ijms12117898] [Citation(s) in RCA: 110] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Revised: 11/04/2011] [Accepted: 11/07/2011] [Indexed: 11/16/2022] Open
Abstract
Rhizobia are Gram-negative bacteria that can exist either as free-living bacteria or as nitrogen-fixing symbionts inside root nodules of leguminous plants. The composition of the rhizobial outer surface, containing a variety of polysaccharides, plays a significant role in the adaptation of these bacteria in both habitats. Among rhizobial polymers, exopolysaccharide (EPS) is indispensable for the invasion of a great majority of host plants which form indeterminate-type nodules. Various functions are ascribed to this heteropolymer, including protection against environmental stress and host defense, attachment to abiotic and biotic surfaces, and in signaling. The synthesis of EPS in rhizobia is a multi-step process regulated by several proteins at both transcriptional and post-transcriptional levels. Also, some environmental factors (carbon source, nitrogen and phosphate starvation, flavonoids) and stress conditions (osmolarity, ionic strength) affect EPS production. This paper discusses the recent data concerning the function of the genes required for EPS synthesis and the regulation of this process by several environmental signals. Up till now, the synthesis of rhizobial EPS has been best studied in two species, Sinorhizobium meliloti and Rhizobium leguminosarum. The latest data indicate that EPS synthesis in rhizobia undergoes very complex hierarchical regulation, in which proteins engaged in quorum sensing and the regulation of motility genes also participate. This finding enables a better understanding of the complex processes occurring in the rhizosphere which are crucial for successful colonization and infection of host plant roots.
Collapse
Affiliation(s)
- Monika Janczarek
- Department of Genetics and Microbiology, University of M. Curie-Skłodowska, Akademicka 19 st., Lublin 20-033, Poland; E-Mail: ; Tel.: +48-81-537-5974
| |
Collapse
|