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Hawkins JP, Oresnik IJ. The Rhizobium-Legume Symbiosis: Co-opting Successful Stress Management. FRONTIERS IN PLANT SCIENCE 2022; 12:796045. [PMID: 35046982 PMCID: PMC8761673 DOI: 10.3389/fpls.2021.796045] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 12/02/2021] [Indexed: 05/20/2023]
Abstract
The interaction of bacteria with plants can result in either a positive, negative, or neutral association. The rhizobium-legume interaction is a well-studied model system of a process that is considered a positive interaction. This process has evolved to require a complex signal exchange between the host and the symbiont. During this process, rhizobia are subject to several stresses, including low pH, oxidative stress, osmotic stress, as well as growth inhibiting plant peptides. A great deal of work has been carried out to characterize the bacterial response to these stresses. Many of the responses to stress are also observed to have key roles in symbiotic signaling. We propose that stress tolerance responses have been co-opted by the plant and bacterial partners to play a role in the complex signal exchange that occurs between rhizobia and legumes to establish functional symbiosis. This review will cover how rhizobia tolerate stresses, and how aspects of these tolerance mechanisms play a role in signal exchange between rhizobia and legumes.
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Affiliation(s)
| | - Ivan J. Oresnik
- Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada
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2
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Abstract
Rhizobia are α- and β-proteobacteria that form a symbiotic partnership with legumes, fixing atmospheric dinitrogen to ammonia and providing it to the plant. Oxygen regulation is key in this symbiosis. Fixation is performed by an oxygen-intolerant nitrogenase enzyme but requires respiration to meet its high energy demands. To satisfy these opposing constraints the symbiotic partners cooperate intimately, employing a variety of mechanisms to regulate and respond to oxygen concentration. During symbiosis rhizobia undergo significant changes in gene expression to differentiate into nitrogen-fixing bacteroids. Legumes host these bacteroids in specialized root organs called nodules. These generate a near-anoxic environment using an oxygen diffusion barrier, oxygen-binding leghemoglobin and control of mitochondria localization. Rhizobia sense oxygen using multiple interconnected systems which enable a finely-tuned response to the wide range of oxygen concentrations they experience when transitioning from soil to nodules. The oxygen-sensing FixL-FixJ and hybrid FixL-FxkR two-component systems activate at relatively high oxygen concentration and regulate fixK transcription. FixK activates the fixNOQP and fixGHIS operons producing a high-affinity terminal oxidase required for bacterial respiration in the microaerobic nodule. Additionally or alternatively, some rhizobia regulate expression of these operons by FnrN, an FNR-like oxygen-sensing protein. The final stage of symbiotic establishment is activated by the NifA protein, regulated by oxygen at both the transcriptional and protein level. A cross-species comparison of these systems highlights differences in their roles and interconnections but reveals common regulatory patterns and themes. Future work is needed to establish the complete regulon of these systems and identify other regulatory signals.
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Affiliation(s)
- Paul J Rutten
- Department of Plant Sciences, University of Oxford, Oxford, United Kingdom
| | - Philip S Poole
- Department of Plant Sciences, University of Oxford, Oxford, United Kingdom
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3
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Bourassa DV, Kannenberg EL, Sherrier DJ, Buhr RJ, Carlson RW. The Lipopolysaccharide Lipid A Long-Chain Fatty Acid Is Important for Rhizobium leguminosarum Growth and Stress Adaptation in Free-Living and Nodule Environments. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2017; 30:161-175. [PMID: 28054497 DOI: 10.1094/mpmi-11-16-0230-r] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Rhizobium bacteria live in soil and plant environments, are capable of inducing symbiotic nodules on legumes, invade these nodules, and develop into bacteroids that fix atmospheric nitrogen into ammonia. Rhizobial lipopolysaccharide (LPS) is anchored in the bacterial outer membrane through a specialized lipid A containing a very long-chain fatty acid (VLCFA). VLCFA function for rhizobial growth in soil and plant environments is not well understood. Two genes, acpXL and lpxXL, encoding acyl carrier protein and acyltransferase, are among the six genes required for biosynthesis and transfer of VLCFA to lipid A. Rhizobium leguminosarum mutant strains acpXL, acpXL-/lpxXL-, and lpxXL- were examined for LPS structure, viability, and symbiosis. Mutations in acpXL and lpxXL abolished VLCFA attachment to lipid A. The acpXL mutant transferred a shorter acyl chain instead of VLCFA. Strains without lpxXL neither added VLCFA nor a shorter acyl chain. In all strains isolated from nodule bacteria, lipid A had longer acyl chains compared with laboratory-cultured bacteria, whereas mutant strains displayed altered membrane properties, modified cationic peptide sensitivity, and diminished levels of cyclic β-glucans. In pea nodules, mutant bacteroids were atypically formed and nitrogen fixation and senescence were affected. The role of VLCFA for rhizobial environmental fitness is discussed.
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Affiliation(s)
- Dianna V Bourassa
- 1 Complex Carbohydrate Research Center, University of Georgia, Athens 30602, U.S.A
- 3 U.S. National Poultry Research Center, Agricultural Research Service, United States Department of Agriculture, Athens, GA 30605, U.S.A
| | - Elmar L Kannenberg
- 1 Complex Carbohydrate Research Center, University of Georgia, Athens 30602, U.S.A
| | - D Janine Sherrier
- 2 Department of Plant and Soil Sciences and Delaware Biotechnology Institute, University of Delaware, Newark 19711, U.S.A.; and
| | - R Jeffrey Buhr
- 3 U.S. National Poultry Research Center, Agricultural Research Service, United States Department of Agriculture, Athens, GA 30605, U.S.A
| | - Russell W Carlson
- 1 Complex Carbohydrate Research Center, University of Georgia, Athens 30602, U.S.A
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4
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Lipopolysaccharide O-chain core region required for cellular cohesion and compaction of in vitro and root biofilms developed by Rhizobium leguminosarum. Appl Environ Microbiol 2014; 81:1013-23. [PMID: 25416773 DOI: 10.1128/aem.03175-14] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The formation of biofilms is an important survival strategy allowing rhizobia to live on soil particles and plant roots. Within the microcolonies of the biofilm developed by Rhizobium leguminosarum, rhizobial cells interact tightly through lateral and polar connections, forming organized and compact cell aggregates. These microcolonies are embedded in a biofilm matrix, whose main component is the acidic exopolysaccharide (EPS). Our work shows that the O-chain core region of the R. leguminosarum lipopolysaccharide (LPS) (which stretches out of the cell surface) strongly influences bacterial adhesive properties and cell-cell cohesion. Mutants defective in the O chain or O-chain core moiety developed premature microcolonies in which lateral bacterial contacts were greatly reduced. Furthermore, cell-cell interactions within the microcolonies of the LPS mutants were mediated mostly through their poles, resulting in a biofilm with an altered three-dimensional structure and increased thickness. In addition, on the root epidermis and on root hairs, O-antigen core-defective strains showed altered biofilm patterns with the typical microcolony compaction impaired. Taken together, these results indicate that the surface-exposed moiety of the LPS is crucial for proper cell-to-cell interactions and for the formation of robust biofilms on different surfaces.
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Berry AM, Mendoza-Herrera A, Guo YY, Hayashi J, Persson T, Barabote R, Demchenko K, Zhang S, Pawlowski K. New perspectives on nodule nitrogen assimilation in actinorhizal symbioses. FUNCTIONAL PLANT BIOLOGY : FPB 2011; 38:645-652. [PMID: 32480919 DOI: 10.1071/fp11095] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2011] [Accepted: 06/10/2011] [Indexed: 06/11/2023]
Abstract
Nitrogen-fixing root nodules are plant organs specialised for symbiotic transfer of nitrogen and carbon between microsymbiont and host. The organisation of nitrogen assimilation, storage and transport processes is partitioned at the subcellular and tissue levels, in distinctive patterns depending on the symbiotic partners. In this review, recent advances in understanding of actinorhizal nodule nitrogen assimilation are presented. New findings indicate that Frankia within nodules of Datisca glomerata (Presl.) Baill. carries out both primary nitrogen assimilation and biosynthesis of arginine, rather than exporting ammonium. Arginine is a typical storage form of nitrogen in plant tissues, but is a novel nitrogen carrier molecule in root nodule symbioses. Thus Frankia within D. glomerata nodules exhibits considerable metabolic independence. Furthermore, nitrogen reassimilation is likely to take place in the host in the uninfected nodule cortical cells of this root nodule symbiosis, before amino acid export to host sink tissues via the xylem. The role of an augmented pericycle in carbon and nitrogen exchange in root nodules deserves further attention in actinorhizal symbiosis, and further highlights the importance of a comprehensive, structure-function approach to understanding function in root nodules. Moreover, the multiple patterns of compartmentalisation in relation to nitrogen flux within root nodules demonstrate the diversity of possible functional interactions between host and microsymbiont that have evolved in the nitrogen-fixing clade.
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Affiliation(s)
- Alison M Berry
- Department of Plant Sciences, University of California, Davis, CA 95616, USA
| | - Alberto Mendoza-Herrera
- Centro de Biotecnología Genómica, Instituto Politécnico Nacional, 88710 Reynosa, Tamaulipas, Mexico
| | - Ying-Yi Guo
- Department of Plant Sciences, University of California, Davis, CA 95616, USA
| | - Jennifer Hayashi
- Department of Plant Sciences, University of California, Davis, CA 95616, USA
| | - Tomas Persson
- Department of Botany, Stockholm University, 10691 Stockholm, Sweden
| | - Ravi Barabote
- Department of Plant Sciences, University of California, Davis, CA 95616, USA
| | - Kirill Demchenko
- Komarov Botanical Institute, Russian Academy of Sciences, St Petersburg 197376, Russia
| | - Shuxiao Zhang
- Department of Plant Sciences, University of California, Davis, CA 95616, USA
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6
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Schubert M, Koteyeva NK, Wabnitz PW, Santos P, Büttner M, Sauer N, Demchenko K, Pawlowski K. Plasmodesmata distribution and sugar partitioning in nitrogen-fixing root nodules of Datisca glomerata. PLANTA 2011; 233:139-52. [PMID: 20938679 PMCID: PMC3015196 DOI: 10.1007/s00425-010-1285-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Accepted: 09/21/2010] [Indexed: 05/25/2023]
Abstract
To understand carbon partitioning in roots and nodules of Datisca glomerata, activities of sucrose-degrading enzymes and sugar transporter expression patterns were analyzed in both organs, and plasmodesmal connections between nodule cortical cells were examined by transmission electron microscopy. The results indicate that in nodules, the contribution of symplastic transport processes is increased in comparison to roots, specifically in infected cells which develop many secondary plasmodesmata. Invertase activities are dramatically reduced in nodules as compared to roots, indicating that here the main enzyme responsible for the cleavage of sucrose is sucrose synthase. A high-affinity, low-specificity monosaccharide transporter whose expression is induced in infected cells prior to the onset of bacterial nitrogen fixation, and which has an unusually low pH optimum and may be involved in turgor control or hexose retrieval during infection thread growth.
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Affiliation(s)
- Maria Schubert
- Albrecht-von-Haller-Institut für Pflanzenwissenschaften, Biochemie der Pflanze, Georg-August-Universität Göttingen, Justus-von-Liebig-Weg 11, 37077 Göttingen, Germany
| | - Nouria K. Koteyeva
- Laboratory of Anatomy and Morphology, Komarov Botanical Institute, Russian Academy of Sciences, Prof. Popov st. 2, 197376 St. Petersburg, Russia
| | - Philipp W. Wabnitz
- Albrecht-von-Haller-Institut für Pflanzenwissenschaften, Biochemie der Pflanze, Georg-August-Universität Göttingen, Justus-von-Liebig-Weg 11, 37077 Göttingen, Germany
| | - Patricia Santos
- Department of Botany, Stockholm University, Lilla Frescativägen 5, 10691 Stockholm, Sweden
| | - Michael Büttner
- Abteilung für Molekulare Pflanzenphysiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstr. 5, 91058 Erlangen, Germany
| | - Norbert Sauer
- Abteilung für Molekulare Pflanzenphysiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstr. 5, 91058 Erlangen, Germany
| | - Kirill Demchenko
- Laboratory of Anatomy and Morphology, Komarov Botanical Institute, Russian Academy of Sciences, Prof. Popov st. 2, 197376 St. Petersburg, Russia
- All-Russia Research Institute for Agricultural Microbiology, Laboratory of Molecular and Cellular Biology, Podbelsky Chaussee 3, Pushkin 8, 196608 St. Petersburg, Russia
| | - Katharina Pawlowski
- Albrecht-von-Haller-Institut für Pflanzenwissenschaften, Biochemie der Pflanze, Georg-August-Universität Göttingen, Justus-von-Liebig-Weg 11, 37077 Göttingen, Germany
- Department of Botany, Stockholm University, Lilla Frescativägen 5, 10691 Stockholm, Sweden
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Gu X, Lee SG, Bar-Peled M. Biosynthesis of UDP-xylose and UDP-arabinose in Sinorhizobium meliloti 1021: first characterization of a bacterial UDP-xylose synthase, and UDP-xylose 4-epimerase. MICROBIOLOGY-SGM 2010; 157:260-269. [PMID: 20847005 PMCID: PMC3068629 DOI: 10.1099/mic.0.040758-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Sinorhizobium meliloti is a soil bacterium that fixes nitrogen after being established inside nodules that can form on the roots of several legumes, including Medicago truncatula. A mutation in an S. meliloti gene (lpsB) required for lipopolysaccharide synthesis has been reported to result in defective nodulation and an increase in the synthesis of a xylose-containing glycan. Glycans containing xylose as well as arabinose are also formed by other rhizobial species, but little is known about their structures and the biosynthetic pathways leading to their formation. To gain insight into the biosynthesis of these glycans and their biological roles, we report the identification of an operon in S. meliloti 1021 that contains two genes encoding activities not previously described in bacteria. One gene encodes a UDP-xylose synthase (Uxs) that converts UDP-glucuronic acid to UDP-xylose, and the second encodes a UDP-xylose 4-epimerase (Uxe) that interconverts UDP-xylose and UDP-arabinose. Similar genes were also identified in other rhizobial species, including Rhizobium leguminosarum, suggesting that they have important roles in the life cycle of this agronomically important class of bacteria. Functional studies established that recombinant SmUxs1 is likely to be active as a dimer and is inhibited by NADH and UDP-arabinose. SmUxe is inhibited by UDP-galactose, even though this nucleotide sugar is not a substrate for the 4-epimerase. Unambiguous evidence for the conversions of UDP-glucuronic acid to UDP-α-d-xylose and then to UDP-β-l-arabinose (UDP-arabinopyranose) was obtained using real-time 1H-NMR spectroscopy. Our results provide new information about the ability of rhizobia to form UDP-xylose and UDP-arabinose, which are then used for the synthesis of xylose- and arabinose-containing glycans.
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Affiliation(s)
- Xiaogang Gu
- Complex Carbohydrate Research Center (CCRC), University of Georgia, Athens, GA 30602, USA
| | - Sung G Lee
- Complex Carbohydrate Research Center (CCRC), University of Georgia, Athens, GA 30602, USA
| | - Maor Bar-Peled
- Department of Plant Biology, University of Georgia, Athens, GA 30602, USA.,Complex Carbohydrate Research Center (CCRC), University of Georgia, Athens, GA 30602, USA
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Labes G, Ulrich A, Lentzsch P. Influence of Bovine Slurry Deposition on the Structure of Nodulating Rhizobium leguminosarum bv. viciae Soil Populations in a Natural Habitat. Appl Environ Microbiol 2010; 62:1717-22. [PMID: 16535318 PMCID: PMC1388856 DOI: 10.1128/aem.62.5.1717-1722.1996] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The population of nodulating R. leguminosarum bv. viciae in soil from a grass-covered valley area which had been used for bovine slurry deposition over a period of 5 years was analyzed. For these studies, a rapid and reproducible method based on enterobacterial repetitive intergenic consensus (ERIC)-PCR was applied to identify Rhizobium strains which had infected pea nodules. Soil samples were taken from different areas and further analyzed in plant tests to determine the impact of the application of slurry (polluted or nonpolluted), the slope position (summit or toe), and exposure (north or south). After comparison of all PCR fingerprint patterns, 24 strain groups were defined. Some strain groups from the nonpolluted soil were suppressed in the polluted samples, and new strain groups were detected in the slurry-polluted soil. After analyzing relationships between the strain groups, we determined the influences of local factors on the nodulating R. leguminosarum bv. viciae population. We show that one of those local parameters, slope position, had significantly greater impact on the composition of the Rhizobium population than the presence of slurry.
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Reguera M, Wimmer M, Bustos P, Goldbach HE, Bolaños L, Bonilla I. Ligands of boron in Pisum sativum nodules are involved in regulation of oxygen concentration and rhizobial infection. PLANT, CELL & ENVIRONMENT 2010; 33:1039-48. [PMID: 20132519 DOI: 10.1111/j.1365-3040.2010.02125.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Boron (B) is an essential nutrient for N(2)-fixing legume-rhizobia symbioses, and the capacity of borate ions to bind and stabilize biomolecules is the basis of any B function. We used a borate-binding-specific resin and immunostaining techniques to identify B ligands important for the development of Pisum sativum-Rhizobium leguminosarum 3841 symbiotic nodules. arabinogalactan-extensin (AGPE), recognized by MAC 265 antibody, appeared heavily bound to the resin in extracts derived from B-sufficient, but not from B-deficient nodules. MAC 265 stained the infection threads and the extracellular matrix of cortical cells involved in the oxygen diffusion barrier. In B-deprived nodules, immunolocalization of MAC 265 antigens was significantly reduced. Leghaemoglobin (Lb) concentration largely decreased in B-deficient nodules. The absence of MAC 203 antigens in B-deficient nodules suggests a high internal oxygen concentration, as this antibody detects an epitope on the lipopolysaccharide (LPS) of bacteroids typically expressed in micro-aerobically grown R. leguminosarum 3841. However, B-deprived nodules did not accumulate oxidized lipids and proteins, and revealed a decrease in the activity of the major antioxidant enzyme ascorbate peroxidase (APX). Therefore, B deficiency reduced the stability of nodule macromolecules important for rhizobial infection, and for regulation of oxygen concentration, resulting in non-functional nodules, but did not appear to induce oxidative damage in low-B nodules.
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Affiliation(s)
- María Reguera
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Darwin 2, 28049-Madrid, Spain
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Abstract
The establishment of nitrogen-fixing symbiosis between a legume plant and its rhizobial symbiont requires that the bacterium adapt to changing conditions that occur with the host plant that both promotes and allows infection of the host root nodule cell, regulates and resists the host defense response, permits the exchange of metabolites, and contributes to the overall health of the host. This adaptive process involves changes to the bacterial cell surface and, therefore, structural modifications to the lipopolysaccharide (LPS). In this chapter, we describe the structures of the LPSs from symbiont members of the Rhizobiales, the genetics and mechanism of their biosynthesis, the modifications that occur during symbiosis, and their possible functions.
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Reguera M, Lloret J, Margaret I, Vinardell JM, Martín M, Buendía A, Rivilla R, Ruiz-Sainz JE, Bonilla I, Bolaños L. GeneSMb21071of plasmid pSymB is required for osmoadaptation ofSinorhizobium meliloti1021 and is implicated in modifications of cell surface polysaccharides structure in response to hyperosmotic stress. Can J Microbiol 2009; 55:1145-52. [DOI: 10.1139/w09-073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Megaplasmid pSymB of the nitrogen-fixing symbiont Sinorhizobium meliloti , implicated in adaptation to hyperosmotic stress, contains 11 gene clusters that apparently encode surface polysaccharides. However, only 2 of these clusters, containing the exo and exp genes, have been associated with the synthesis of the acidic exopolysaccharides succinoglycan and galactoglucan, respectively. The functions of the other 9 clusters remain unsolved. The involvement of one of those regions, pSymB cluster 3, on surface polysaccharide synthesis and its possible implication in osmoadaptation were investigated. In silico analysis of cluster 3 showed that it putatively encodes for the synthesis and transport of a methylated surface polysaccharide. Mutants affected in this cluster were symbiotically effective but showed defects in growth under saline and nonsaline osmotic stress. The gene SMb21071, encoding a putative initiating glycosyltransferase, is transcriptionally induced under hyperosmotic conditions. Sodium dodecyl sulfate – polyacrylamide gel electrophoresis and silver staining showed that osmotic stresses changed the profiles of surface polysaccharides of wild-type and mutants strains in different ways. The overall results suggest that cluster 3 is important for growth under saline stress and essential for growth under nonsaline hyperosmotic stress, and it appears to be implicated in maintaining and (or) modifying surface polysaccharides in response to osmotic stress.
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Affiliation(s)
- María Reguera
- Departamento de Biologia, Facultad de Ciencias, Universidad Autonoma de Madrid, Darwin 2, 28049-Madrid, Spain
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12
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Tang H, Wang E, Sui X, Man C, Jia R, Lin D, Qu Z, Chen W. The novel alkali tolerance function of tfxG in Sinorhizobium meliloti. Res Microbiol 2007; 158:501-5. [PMID: 17566711 DOI: 10.1016/j.resmic.2007.04.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2006] [Revised: 04/11/2007] [Accepted: 04/11/2007] [Indexed: 11/17/2022]
Abstract
TfxG, one of the tfxABCDEFG cluster genes that code for trifolitoxin (TFX) production, was initially described in Rhizobium leguminosarum bv. trifolii T24. Although several genes in the tfx family have functions related to TFX production or resistance to TFX, the function of tfxG is largely unknown. Using cDNA-amplified fragment length polymorphism (cDNA-AFLP) analysis, we found that expression of the tfxG gene dramatically increased under alkaline culture conditions in Sinorhizobium meliloti CCBAU 81024. This result was confirmed by northern blot analysis. Mutagenesis of tfxG significantly decreased the viability of Sinorhizobium meliloti CCBAU 81024 under alkali stress. Complementation of the tfxG mutant strain using the functional tfxG gene recovered its alkali tolerance to a wild-type level. Genomic analysis of the tfxG gene suggests that choline and homoserine kinase domains may contribute to its alkali tolerance function. This is the first clear evidence that tfxG plays a crucial role in the alkali tolerance of S. meliloti CCBAU 81024, and the finding provides its biological function.
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Affiliation(s)
- Hui Tang
- Key Laboratory of Agro-Microbial Resource and Application, Ministry of Agriculture/College of Biological Sciences, China Agricultural University, Beijing 100094, China
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13
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D'Haeze W, Leoff C, Freshour G, Noel KD, Carlson RW. Rhizobium etli CE3 bacteroid lipopolysaccharides are structurally similar but not identical to those produced by cultured CE3 bacteria. J Biol Chem 2007; 282:17101-13. [PMID: 17420254 DOI: 10.1074/jbc.m611669200] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Rhizobium etli CE3 bacteroids were isolated from Phaseolus vulgaris root nodules. The lipopolysaccharide (LPS) from the bacteroids was purified and compared with the LPS from laboratory-cultured R. etli CE3 and from cultures grown in the presence of anthocyanin. Comparisons were made of the O-chain polysaccharide, the core oligosaccharide, and the lipid A. Although LPS from CE3 bacteria and bacteroids are structurally similar, it was found that bacteroid LPS had specific modifications to both the O-chain polysaccharide and lipid A portions of their LPS. Cultures grown with anthocyanin contained modifications only to the O-chain polysaccharide. The changes to the O-chain polysaccharide consisted of the addition of a single methyl group to the 2-position of a fucosyl residue in one of the five O-chain trisaccharide repeat units. This same change occurred for bacteria grown in the presence of anthocyanin. This methylation change correlated with the inability of bacteroid LPS and LPS from anthocyanin-containing cultures to bind the monoclonal antibody JIM28. The core oligosaccharide region of bacteroid LPS and from anthocyanin-grown cultures was identical to that of LPS from normal laboratory-cultured CE3. The lipid A from bacteroids consisted exclusively of a tetraacylated species compared with the presence of both tetra- and pentaacylated lipid A from laboratory cultures. Growth in the presence of anthocyanin did not affect the lipid A structure. Purified bacteroids that could resume growth were also found to be more sensitive to the cationic peptides, poly-l-lysine, polymyxin-B, and melittin.
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Affiliation(s)
- Wim D'Haeze
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602, USA
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14
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Vedam V, Kannenberg E, Datta A, Brown D, Haynes-Gann JG, Sherrier DJ, Carlson RW. The pea nodule environment restores the ability of a Rhizobium leguminosarum lipopolysaccharide acpXL mutant to add 27-hydroxyoctacosanoic acid to its lipid A. J Bacteriol 2006; 188:2126-33. [PMID: 16513742 PMCID: PMC1428142 DOI: 10.1128/jb.188.6.2126-2133.2006] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2005] [Accepted: 12/22/2005] [Indexed: 11/20/2022] Open
Abstract
Members of the Rhizobiaceae contain 27-hydroxyoctacosanoic acid (27OHC(28:0)) in their lipid A. A Rhizobium leguminosarum 3841 acpXL mutant (named here Rlv22) lacking a functional specialized acyl carrier lacked 27OHC(28:0) in its lipid A, had altered growth and physiological properties (e.g., it was unable to grow in the presence of an elevated salt concentration [0.5% NaCl]), and formed irregularly shaped bacteroids, and the synchronous division of this mutant and the host plant-derived symbiosome membrane was disrupted. In spite of these defects, the mutant was able to persist within the root nodule cells and eventually form, albeit inefficiently, nitrogen-fixing bacteroids. This result suggested that while it is in a host root nodule, the mutant may have some mechanism by which it adapts to the loss of 27OHC(28:0) from its lipid A. In order to further define the function of this fatty acyl residue, it was necessary to examine the lipid A isolated from mutant bacteroids. In this report we show that addition of 27OHC(28:0) to the lipid A of Rlv22 lipopolysaccharides is partially restored in Rlv22 acpXL mutant bacteroids. We hypothesize that R. leguminosarum bv. viciae 3841 contains an alternate mechanism (e.g., another acp gene) for the synthesis of 27OHC(28:0), which is activated when the bacteria are in the nodule environment, and that it is this alternative mechanism which functionally replaces acpXL and is responsible for the synthesis of 27OHC(28:0)-containing lipid A in the Rlv22 acpXL bacteroids.
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Affiliation(s)
- Vinata Vedam
- University of Georgia, Complex Carbohydrate Research Center, 315 Riverbend Rd., Athens, GA 30602, USA
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15
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Noel KD, Box JM, Bonne VJ. 2-O-methylation of fucosyl residues of a rhizobial lipopolysaccharide is increased in response to host exudate and is eliminated in a symbiotically defective mutant. Appl Environ Microbiol 2004; 70:1537-44. [PMID: 15006776 PMCID: PMC368319 DOI: 10.1128/aem.70.3.1537-1544.2004] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
When Rhizobium etli CE3 was grown in the presence of Phaseolus vulgaris seed extracts containing anthocyanins, its lipopolysaccharide (LPS) sugar composition was changed in two ways: greatly decreased content of what is normally the terminal residue of the LPS, di-O-methylfucose, and a doubling of the 2-O-methylation of other fucose residues in the LPS O antigen. R. etli strain CE395 was isolated after Tn5 mutagenesis of strain CE3 by screening for mutant colonies that did not change antigenically in the presence of seed extract. The LPS of this strain completely lacked 2-O-methylfucose, regardless of whether anthocyanins were present during growth. The mutant gave only pseudonodules in association with P. vulgaris. Interpretation of this phenotype was complicated by a second LPS defect exhibited by the mutant: its LPS population had only about 50% of the normal amount of O-antigen-containing LPS (LPS I). The latter defect could be suppressed genetically such that the resulting strain (CE395 alpha 395) synthesized the normal amount of an LPS I that still lacked 2-O-methylfucose residues. Strain CE395 alpha 395 did not elicit pseudonodules but resulted in significantly slower nodule development, fewer nodules, and less nitrogenase activity than lps(+) strains. The relative symbiotic deficiency was more severe when seeds were planted and inoculated with bacteria before they germinated. These results support previous conclusions that the relative amount of LPS I on the bacterial surface is crucial in symbiosis, but LPS structural features, such as 2-O-methylation of fucose, also may facilitate symbiotic interactions.
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Affiliation(s)
- K Dale Noel
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin 53201, USA.
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16
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Karbarz MJ, Kalb SR, Cotter RJ, Raetz CRH. Expression cloning and biochemical characterization of a Rhizobium leguminosarum lipid A 1-phosphatase. J Biol Chem 2003; 278:39269-79. [PMID: 12869541 PMCID: PMC2553562 DOI: 10.1074/jbc.m305830200] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Lipid A of Rhizobium leguminosarum, a nitrogen-fixing plant endosymbiont, displays several significant structural differences when compared with Escherichia coli. An especially striking feature of R. leguminosarum lipid A is that it lacks both the 1- and 4'-phosphate groups. Distinct lipid A phosphatases that attack either the 1 or the 4' positions have previously been identified in extracts of R. leguminosarum and Rhizobium etli but not Sinorhizobium meliloti or E. coli. Here we describe the identification of a hybrid cosmid (pMJK-1) containing a 25-kb R. leguminosarum 3841 DNA insert that directs the overexpression of the lipid A 1-phosphatase. Transfer of pMJK-1 into S. meliloti 1021 results in heterologous expression of 1-phosphatase activity, which is normally absent in extracts of strain 1021, and confers resistance to polymyxin. Sequencing of a 7-kb DNA fragment derived from the insert of pMJK-1 revealed the presence of a lipid phosphatase ortholog (designated LpxE). Expression of lpxE in E. coli behind the T7lac promoter results in the appearance of robust 1-phosphatase activity, which is normally absent in E. coli membranes. Matrix-assisted laser-desorption/time of flight and radiochemical analysis of the product generated in vitro from the model substrate lipid IVA confirms the selective removal of the 1-phosphate group. These findings show that lpxE is the structural gene for the 1-phosphatase. The availability of lpxE may facilitate the re-engineering of lipid A structures in diverse Gram-negative bacteria and allow assessment of the role of the 1-phosphatase in R. leguminosarum symbiosis with plants. Possible orthologs of LpxE are present in some intracellular human pathogens, including Francisella tularensis, Brucella melitensis, and Legionella pneumophila.
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Affiliation(s)
- Mark J. Karbarz
- Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710
| | - Suzanne R. Kalb
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Robert J. Cotter
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Christian R. H. Raetz
- Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710
- To whom correspondence should be addressed: Dept. of Biochemistry, Duke University Medical Center, P.O. Box 3711, Durham, NC 27710. Tel.: 919-684-5326; Fax: 919-684-8885; E-mail:
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17
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Vedam V, Kannenberg EL, Haynes JG, Sherrier DJ, Datta A, Carlson RW. A Rhizobium leguminosarum AcpXL mutant produces lipopolysaccharide lacking 27-hydroxyoctacosanoic acid. J Bacteriol 2003; 185:1841-50. [PMID: 12618448 PMCID: PMC150140 DOI: 10.1128/jb.185.6.1841-1850.2003] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2002] [Accepted: 12/16/2002] [Indexed: 11/20/2022] Open
Abstract
The structure of the lipid A from Rhizobium etli and Rhizobium leguminosarum lipopolysaccharides (LPSs) lacks phosphate and contains a galacturonosyl residue at its 4' position, an acylated 2-aminogluconate in place of the proximal glucosamine, and a very long chain omega-1 hydroxy fatty acid, 27-hydroxyoctacosanoic acid (27OHC28:0). The 27OHC28:0 moiety is common in lipid A's among members of the Rhizobiaceae and also among a number of the facultative intracellular pathogens that form chronic infections, e.g., Brucella abortus, Bartonella henselae, and Legionella pneumophila. In this paper, a mutant of R. leguminosarum was created by placing a kanamycin resistance cassette within acpXL, the gene which encodes the acyl carrier protein for 27OHC28:0. The result was an LPS containing a tetraacylated lipid A lacking 27OHC28:0. A small amount of the mutant lipid A may contain an added palmitic acid residue. The mutant is sensitive to changes in osmolarity and an increase in acidity, growth conditions that likely occur in the nodule microenvironment. In spite of the probably hostile microenvironment of the nodule, the acpXL mutant is still able to form nitrogen-fixing root nodules even though the appearance and development of nodules are delayed. Therefore, it is possible that the acpXL mutant has a host-inducible mechanism which enables it to adapt to these physiological changes.
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Affiliation(s)
- Vinata Vedam
- Carbohydrate Research Center, University of Georgia Complex, Athens, Georgia 30602, USA
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18
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Hynes RK, Jans DC, Bremer E, Lupwayi NZ, Rice WA, Clayton GW, Collins MM. Rhizobium population dynamics in the pea rhizosphere of rhizobial inoculant strain applied in different formulations. Can J Microbiol 2001; 47:595-600. [PMID: 11547878 DOI: 10.1139/w01-047] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effect of inoculant formulation on the population dynamics of rhizobia in the pea rhizosphere was investigated using a streptomycin-resistant mutant of Rhizobium leguminosarum bv. viceae NITRAGIN128C56G (128C56G strR). The isolate was formulated into liquid, peat powder, and granular peat carriers, and was tested on pea at field sites near Saskatoon, Saskatchewan, and Beaverlodge, Alberta, in 1996 and 1997. The liquid and peat powder formulations were applied to seed while the granular inoculant was applied to soil. In three out of four site years, population dynamics were similar among formulations: an initial decline or lag period lasting 2-5 days followed by an increase to approximately 10(5) colony-forming units (CFU)/seedling by 14-28 days after planting (DAP) and, where sampled, a continuing increase from 10(7) to 10(8) CFU/plant at 63 DAP. In these same site years, nodule number (not determined at Beaverlodge in 1997) and nodule occupancy at 60 days were not significantly different among formulations. In contrast, soil populations of 128C56G strR from the liquid formulation declined to near zero by 28 DAP at Beaverlodge in 1996, when soil moisture was excessive in spring because of high rainfall. Populations increased in this treatment after this time, but remained significantly lower than the populations of the other two formulations throughout the sampling period. Pea seed yields were not significantly different among treatments in either year at Beaverlodge, but were significantly higher with granular inoculant than the noninoculated control in Saskatoon. Within inoculated treatments at Saskatoon, there were no significant differences in grain yield.
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Affiliation(s)
- R K Hynes
- Agrium Inc., Ag Biologicals, Saskatoon, SK, Canada.
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19
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Kannenberg EL, Carlson RW. Lipid A and O-chain modifications cause Rhizobium lipopolysaccharides to become hydrophobic during bacteroid development. Mol Microbiol 2001; 39:379-91. [PMID: 11136459 DOI: 10.1046/j.1365-2958.2001.02225.x] [Citation(s) in RCA: 119] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Modifications to the lipopolysaccharide (LPS) structure caused by three different growth conditions were investigated in the pea-nodulating strain Rhizobium leguminosarum 3841. The LPSs extracted by hot phenol-water from cultured cells fractionated into hydrophilic water and/or hydrophobic phenol phases. Most of the LPSs from cells grown under standard conditions extracted into the water phase, but a greater proportion of LPSs were extracted into the phenol phase from cells grown under acidic or reduced-oxygen conditions, or when isolated from root nodules as bacteroids. Compared with the water-extracted LPSs, the phenol-extracted LPSs contained greater degrees of glycosyl methylation and O-acetylation, increased levels of xylose, glucose and mannose and increased amounts of long-chain fatty acids attached to the lipid A moiety. The water- and phenol-phase LPSs also differed in their reactivity with monoclonal antibodies and in their polyacrylamide gel electrophoretic banding patterns. Phenol-extracted LPSs from rhizobia grown under reduced-oxygen conditions closely resembled the bulk of LPSs isolated from pea nodule bacteria (i.e. mainly bacteroids) in their chemical properties, reactivities with monoclonal antibodies and extraction behaviour. This finding suggests that, during symbiotic bacteroid development, reduced oxygen tension induces structural modifications in LPSs that cause a switch from predominantly hydrophilic to predominantly hydrophobic molecular forms. Increased hydrophobicity of LPSs was also positively correlated with an increase in the surface hydrophobicity of whole cells, as shown by the high degree of adhesion to hydrocarbons of bacterial cells isolated from nodules or from cultures grown under low-oxygen conditions. The implications of these LPS modifications are discussed for rhizobial survival and function in different soil and in planta habitats.
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Affiliation(s)
- E L Kannenberg
- Mikrobiologie/Biotechnologie, Universität Tübingen, Auf der Morgenstelle 28, D-72076 Tübingen, Germany.
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20
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Niehaus K, Becker A. The role of microbial surface polysaccharides in the Rhizobium-legume interaction. Subcell Biochem 1998; 29:73-116. [PMID: 9594645 DOI: 10.1007/978-1-4899-1707-2_3] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- K Niehaus
- Lehrstuhl für Genetik, Fakultät für Biologie, Universität Bielefeld, Germany
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21
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Affiliation(s)
- C Guan
- Department of Molecular Biology, Agricultural University, Wageningen, The Netherlands
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22
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Tang Y, Hollingsworth RI. Regulation of lipid synthesis in Bradyrhizobium japonicum: low oxygen concentrations trigger phosphatidylinositol biosynthesis. Appl Environ Microbiol 1998; 64:1963-6. [PMID: 9572982 PMCID: PMC106261 DOI: 10.1128/aem.64.5.1963-1966.1998] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Lowering oxygen tension in free-living Bradyrhizobium japonicum resulted in a dramatic switch of membrane chemistry in which phosphatidylcholine, the predominant lipid in aerated cultures, was no longer synthesized and phosphatidylethanolamine became the major lipid. Besides this change, phosphatidylinositol, a typical plant lipid rarely found in bacteria, was also synthesized.
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Affiliation(s)
- Y Tang
- Department of Biochemistry, Michigan State University, East Lansing 48824, USA
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23
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Lloret J, Wulff BB, Rubio JM, Downie JA, Bonilla I, Rivilla R. Exopolysaccharide II production is regulated by salt in the halotolerant strain Rhizobium meliloti EFB1. Appl Environ Microbiol 1998; 64:1024-8. [PMID: 9501442 PMCID: PMC106361 DOI: 10.1128/aem.64.3.1024-1028.1998] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The halotolerant strain Rhizobium meliloti EFB1 modifies the production of extracellular polysaccharides in response to salt. EFB1 colonies grown in the presence of 0.3 M NaCl show a decrease in mucoidy, and in salt-supplemented liquid medium this organism produces 40% less exopolysaccharides. We isolated transposon-induced mutant that, when grown in the absence of salt, had a colony morphology (nonmucoid) similar to the colony morphology of the wild type grown in the presence of salt. Calcofluor fluorescence, proton nuclear magnetic resonance spectroscopy, and genetic analysis of the mutant indicated that galactoglucan, which is not produced under normal conditions by other R. meliloti strains, is produced by strain EFB1 and that production of this compound decreases when the organism is grown in the presence of salt. The mutant was found to be affected in a genetic region highly homologous to genes for galactoglucan production in R. meliloti Rm2011 (expE genes). However, sequence divergence occurs in a putative expE promoter region. A transcriptional fusion of the promoter with lacZ demonstrated that, unlike R. meliloti Rm2011, galactoglucan is produced constitutively by EFB1 and that its expression is reduced 10-fold during exponential growth in the presence of salt.
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Affiliation(s)
- J Lloret
- Departamento de Biología, Universidad Autónoma de Madrid, Spain
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24
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Lucas MM, Peart JL, Brewin NJ, Kannenberg EL. Isolation of monoclonal antibodies reacting with the core component of lipopolysaccharide from Rhizobium leguminosarum strain 3841 and mutant derivatives. J Bacteriol 1996; 178:2727-33. [PMID: 8631658 PMCID: PMC178005 DOI: 10.1128/jb.178.10.2727-2733.1996] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Monoclonal antibodies reacting with the core oligosaccharide or lipid A component of Rhizobium lipopolysaccharide (LPS) could be useful for the elucidation of the structure and biosynthesis of this group of macromolecules. Mutant derivatives of Rhizobium leguminosarum 3841 with LPS structures lacking the major O-antigen moiety were used as immunogens, and eight antibodies were selected for further study. All the antibodies reacted with the fast-migrating species known as LPS-2 following gel electrophoresis of Rhizobium cell extracts. For four of these antibodies, reactivity with affinity-purified LPS was lost after mild acid hydrolysis, indicating that they probably recognized the core oligosaccharide component. The four other antibodies still reacted with acid-treated LPS and may recognize the lipid A moiety, which is stable to mild acid hydrolysis. The pattern of antibody staining after gel electrophoresis revealed differences in LPS-2 epitope structure between each of the mutants and the wild type. Furthermore, for each of the mutants the antibodies crossreacted with a minor band that migrated more slowly than LPS-2; we have termed this more slowly migrating form LPS-3. The majority of the antibodies also reacted with LPS from strain CE109, a derivative of Rhizobium etli CE3, confirming that the LPS core antigens can be relatively conserved between strains of different Rhizobium species. One of the antibodies isolated in this study (JIM 32) was unusual because it appeared to react with all forms of LPS from strain 3841 (namely, LPS-1, LPS-2, and LPS-3). Furthermore, JIM 32 reacted positively with the LPS from many strains of Rhizobium tested (excluding the Rhizobium meliloti subgroup). JIM 32 did not react with representative strains from Bradyrhizobium, Azorhizobium or other related bacterial species.
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Affiliation(s)
- M M Lucas
- John Innes Centre, Norwich NR4 7UH, Great Britain
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25
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Tiwari RP, Reeve WG, Dilworthan MJ, Glenn AR. An essential role for actA in acid tolerance of Rhizobium meliloti. MICROBIOLOGY (READING, ENGLAND) 1996; 142 ( Pt 3):601-610. [PMID: 8868435 DOI: 10.1099/13500872-142-3-601] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The actA gene, which is disrupted by Tn5 in the acid-sensitive mutant of Rhizobium meliloti TG2-6, was cloned and sequenced. It encodes a protein of 541 amino acids with a calculated molecular mass of 57,963 Da and an estimated pl of 9.0. The ActA protein sequence has 30% identity, and much higher similarity (69%), with the CutE protein of Escherichia coli. Like the cutE mutant of E. coli, TG2-6 is sensitive to copper. The reconstructed wild-type actA gene complemented the low pH- and copper-sensitive phenotype of TG2-6. Studies with an actA-lacZ gene fusion showed that actA is constitutively expressed at pH 5.8 and 7.0. The actA gene appears to be chromosomal and is present in all seven strains of R. meliloti tested.
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Affiliation(s)
- Ravi P Tiwari
- Nitrogen Fixation Research Group, School of Biological and Environmental Sciences, Murdoch University, Murdoch, Western Australia 6150
| | - Wayne G Reeve
- Nitrogen Fixation Research Group, School of Biological and Environmental Sciences, Murdoch University, Murdoch, Western Australia 6150
| | - Michael J Dilworthan
- Nitrogen Fixation Research Group, School of Biological and Environmental Sciences, Murdoch University, Murdoch, Western Australia 6150
| | - Andrew R Glenn
- Nitrogen Fixation Research Group, School of Biological and Environmental Sciences, Murdoch University, Murdoch, Western Australia 6150
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26
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Nitrogen Fixing Root Nodule Symbioses: Legume Nodules and Actinorhizal Nodules. BIOTECHNOLOGY ANNUAL REVIEW 1996. [DOI: 10.1016/s1387-2656(08)70009-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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27
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Lloret J, Bolanos L, Lucas MM, Peart JM, Brewin NJ, Bonilla I, Rivilla R. Ionic Stress and Osmotic Pressure Induce Different Alterations in the Lipopolysaccharide of a Rhizobium meliloti Strain. Appl Environ Microbiol 1995; 61:3701-4. [PMID: 16535151 PMCID: PMC1388713 DOI: 10.1128/aem.61.10.3701-3704.1995] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A halotolerant strain of Rhizobium meliloti was isolated from nodules of a Melilotus plant growing in a salt marsh in Donana National Park (southwest Spain). This strain, EFB1, is able to grow at NaCl concentrations of up to 500 mM, and no effect on growth is produced by 300 mM NaCl. EFB1 showed alterations on its lipopolysaccharide (LPS) structure that can be related to salt stress: (i) silver-stained electrophoretic profiles showed a different mobility that was dependent on ionic stress but not on osmotic pressure, and (ii) a monoclonal antibody, JIM 40, recognized changes in LPS that were dependent on osmotic stress. Both modifications on LPS may form part of the adaptive mechanism of this bacterium for saline environments.
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28
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Mylona P, Pawlowski K, Bisseling T. Symbiotic Nitrogen Fixation. THE PLANT CELL 1995; 7:869-885. [PMID: 12242391 DOI: 10.2307/3870043] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Affiliation(s)
- P. Mylona
- Department of Molecular Biology, Agricultural University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
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29
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Mylona P, Pawlowski K, Bisseling T. Symbiotic Nitrogen Fixation. THE PLANT CELL 1995; 7:869-885. [PMID: 12242391 PMCID: PMC160880 DOI: 10.1105/tpc.7.7.869] [Citation(s) in RCA: 122] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Affiliation(s)
- P. Mylona
- Department of Molecular Biology, Agricultural University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
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30
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Mylona P, Pawlowski K, Bisseling T. Symbiotic Nitrogen Fixation. THE PLANT CELL 1995. [PMID: 12242391 DOI: 10.1105/2ftpc.7.7.869] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Affiliation(s)
- P. Mylona
- Department of Molecular Biology, Agricultural University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
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31
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Affiliation(s)
- H K Hall
- Department of Microbiology and Immunology, College of Medicine, University of South Alabama, Mobile 36688, USA
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32
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Michiels J, Vanderleyden J. Molecular basis of the establishment and functioning of a N2-fixing root nodule. World J Microbiol Biotechnol 1994; 10:612-30. [DOI: 10.1007/bf00327946] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 07/27/1994] [Accepted: 08/03/1994] [Indexed: 12/01/2022]
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33
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34
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Bhat U, Forsberg L, Carlson R. Structure of lipid A component of Rhizobium leguminosarum bv. phaseoli lipopolysaccharide. Unique nonphosphorylated lipid A containing 2-amino-2-deoxygluconate, galacturonate, and glucosamine. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)36637-1] [Citation(s) in RCA: 130] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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35
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Kannenberg EL, Perotto S, Bianciotto V, Rathbun EA, Brewin NJ. Lipopolysaccharide epitope expression of Rhizobium bacteroids as revealed by in situ immunolabelling of pea root nodule sections. J Bacteriol 1994; 176:2021-32. [PMID: 7511581 PMCID: PMC205308 DOI: 10.1128/jb.176.7.2021-2032.1994] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
To investigate the in situ expression of lipopolysaccharide (LPS) epitopes on nodule bacteria of Rhizobium leguminosarum, monoclonal antibodies recognizing LPS macromolecules were used for immunocytochemical staining of pea nodule tissue. Many LPS epitopes were constitutively expressed, and the corresponding antibodies reacted in nodule sections with bacteria at all stages of tissue infection and cell invasion. Some antibodies, however, recognized epitopes that were only expressed in particular regions of the nodule. Two general patterns of regulated LPS epitope expression could be distinguished on longitudinal sections of nodules. A radial pattern probably reflected the local physiological conditions experienced by endosymbiotic bacteria as a result of oxygen diffusion into the nodule tissue. The other pattern of expression, which followed a linear axis of symmetry along a longitudinal section of the pea nodule, was apparently associated with the differentiation of nodule bacteria and the development of the nitrogen-fixing capacity in bacteroids. Basically similar patterns of LPS epitope expression were observed for pea nodules harboring either of two immunologically distinct strains of R. leguminosarum bv. viciae, although these epitopes were recognized by different sets of strain-specific monoclonal antibodies. Furthermore, LPS epitope expression of rhizobia in pea nodules was compared with that of equivalent strains in nodules of French bean (Phaseolus vulgaris). From these observations, it is suggested that structural modifications of Rhizobium LPS may play an important role in the adaptation of endosymbiotic rhizobia to the surrounding microenvironment.
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36
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Olsen P, Wright S, Collins M, Rice W. Patterns of Reactivity between a Panel of Monoclonal Antibodies and Forage
Rhizobium
Strains. Appl Environ Microbiol 1994; 60:654-61. [PMID: 16349192 PMCID: PMC201362 DOI: 10.1128/aem.60.2.654-661.1994] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A panel of 11 monoclonal antibodies raised against vegetative cells of
Rhizobium leguminosarum
biovar trifolii or
Rhizobium meliloti
was tested by enzyme-linked immunosorbent assay for reactivity with 47 strains of
R. leguminosarum
biovar trifolii and 60 strains of
R. meliloti.
The goal of the study was to define the degree of specificity associated with each antibody and to gain an understanding of the amount of antigenic diversity found among the strains and between the species. Each antibody was tested against each
Rhizobium
strain in four forms: washed steamed cells, washed unsteamed cells, cell-free culture broth, and nodule squash material. Each antibody showed a different pattern of reactivity among the 107 strains. One of each of the antibodies developed against
R. meliloti
and
R. leguminosarum
biovar trifolii reacted in a highly specific manner with cells or antigen from the immunogenic strain only. Nine of the antibodies recognized secreted as well as cellular antigen from many of the strains. Analysis of patterns of reactivity between the 107 strains and the 11 antibodies separated the strains into 28 groups of which 12 were represented by one strain only.
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Affiliation(s)
- P Olsen
- Research Station, Agriculture Canada, Beaverlodge, Alberta, Canada TOH OCO
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37
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Kardailsky I, Yang WC, Zalensky A, van Kammen A, Bisseling T. The pea late nodulin gene PsNOD6 is homologous to the early nodulin genes PsENOD3/14 and is expressed after the leghaemoglobin genes. PLANT MOLECULAR BIOLOGY 1993; 23:1029-1037. [PMID: 8260623 DOI: 10.1007/bf00021817] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The pea late nodulin gene PsNOD6 has been cloned and sequenced. PsNOD6 is homologous to the pea early nodulin genes PsNOD3 and PsENOD14. In situ hybridization experiments showed that, like the PsENOD3 and PsENOD14 genes, the PsNOD6 gene is only expressed in the infected cell type. The PsNOD6 gene is first expressed at the transition of the pre-fixation zone II into the interzone II-III (the amyloplast-rich zone preceding the fixation zone III), whereas the early nodulin genes PsENOD3 and PsENOD14 are already induced in the pre-fixation zone II. Thus these nodulin genes encoding homologous proteins are induced at consecutive stages of nodule development. The expression of the late nodulin genes encoding leghaemoglobin precedes the expression of the late nodulin gene PsNOD6. Therefore these late nodulin genes have to be regulated by different mechanisms despite the fact they are expressed in the same cell type. This conclusion is consistent with the fact that PsNOD6 lacks one of the conserved regions occurring in the promoters of all other late nodulin genes studied.
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Affiliation(s)
- I Kardailsky
- Department of Molecular Biology, Wageningen Agricultural University, Netherlands
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Noonan B, Motherway M, O'Gara F. Ammonia regulation of the Rhizobium meliloti nitrogenase structural and regulatory genes under free-living conditions: involvement of the fixL gene product? MOLECULAR & GENERAL GENETICS : MGG 1992; 234:423-8. [PMID: 1406587 DOI: 10.1007/bf00538701] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The expression under microaerobic conditions of the Rhizobium meliloti nifA and consequently the nifHDK genes was found to be negatively regulated by ammonia and nitrate. Assimilation of the ammonia to glutamate and glutamine is not required for this regulation to occur. This indicates that ammonia itself, and not a product of its metabolism, may be regulating nif expression. Unlike the situation in Klebsiella pneumoniae, NtrC is apparently not involved in mediating the ammonia effect on nifA expression in R. meliloti. Neither does the fixK gene product, which is known to regulate nifA in R. meliloti, appear to be involved in mediating the ammonia effect. The regulation of nifA by ammonia is shown to be mediated through the FixL protein. A truncated fixJ gene, the product of which has been shown to induce nifA expression irrespective of the oxygen status of the cell, also circumvented the repressive effect of ammonia on nifA expression. This suggests that the ammonia effect is mediated through the FixLJ regulatory cascade. Interestingly no effect of ammonia on fixK expression was observed.
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Affiliation(s)
- B Noonan
- Department of Microbiology, University College, Cork, Republic of Ireland
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Kannenberg EL, Rathbun EA, Brewin NJ. Molecular dissection of structure and function in the lipopolysaccharide of Rhizobium leguminosarum strain 3841 using monoclonal antibodies and genetic analysis. Mol Microbiol 1992; 6:2477-87. [PMID: 1383672 DOI: 10.1111/j.1365-2958.1992.tb01424.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Following treatment with nitrosoguanidine, mutant derivatives of Rhizobium leguminosarum strain 3841 were isolated which failed to react with AFRC MAC 203. This monoclonal antibody normally recognizes a strain-specific lipopolysaccharide epitope which is developmentally regulated during legume nodule differentiation. Structural modification of lipopolysaccharide (LPS) was analysed by examining reactivity with a range of monoclonal antibodies with different epitope specificities, and also by analysis of LPS mobility changes after electrophoresis on polyacrylamide gels. One class of these LPS-defective mutants induced normal nitrogen-fixing (Fix+) nodules on peas (Pisum sativum), while another two classes of Fix- mutants were also identified, suggesting that a component of the LPS antigen that is part of the MAC 203 epitope is essential for normal nodule development leading to symbiotic nitrogen fixation. When grown under low-oxygen or low-pH culture conditions, one class of Fix- mutants completely lacked LPS-1 (the species that carries O antigen) and a second class showed a modified and truncated form of LPS-1. Mutants with defective LPS structure were also obtained after Tn5 mutagenesis of R. leguminosarum 3841 and all nine Fix- mutants were also found to lack the MAC 203 epitope. Three of these transposon-induced mutants synthesized a truncated form of LPS-1 that was structurally similar to that of the class of the NTG-induced mutants described above. These transposon-induced mutations, and the nitrosoguanidine-induced Fix- mutations, were closely linked and could be suppressed by the same cloned fragment of chromosomal DNA. The data presented here suggest that a precondition for normal nodule development of R. leguminosarum 3841 within pea nodules is the ability to synthesize relatively long-chain LPS-1 macromolecules under the physiological conditions encountered within the nodule. All mutants that lacked the ability to elongate LPS-1 macromolecules also failed to express the MAC 203 epitope.
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Bhat UR, Carlson RW. Chemical characterization of pH-dependent structural epitopes of lipopolysaccharides from Rhizobium leguminosarum biovar phaseoli. J Bacteriol 1992; 174:2230-5. [PMID: 1372601 PMCID: PMC205843 DOI: 10.1128/jb.174.7.2230-2235.1992] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lipopolysaccharide (LPS) was isolated from free-living Rhizobium leguminosarum bv. phaseoli CE3 cells grown at pH 4.8 (antigenically similar to bacteroid LPS) and compared with that from cells grown at pH 7.2 (free-living bacteria). Composition analysis revealed that pH 7.2 LPS differs from pH 4.8 LPS in that 2,3,4-tri-O-methylfucose is replaced by 2,3-di-O-methylfucose. The amount of 2-O-methylrhamnose is greater in the pH 4.8 LPS than in the pH 7.2 LPS. Analysis of the structural components of LPS (O-chain polysaccharide, core oligosaccharides, and the lipid A) revealed that all the composition differences in the various LPSs occur in the O-chain polysaccharide. These structural variations between pH 4.8 and pH 7.2 LPSs provide a chemical basis for the observed lack of cross-reactivity with pH 4.8 LPS of two monoclonal antibodies, JIM28 and JIM29, raised against free-living bacteria grown at pH 7.2. An LPS preparation isolated from bacteroids contained both 2,3,4-tri-O- and 2,3-di-O-methylfucose residues. This result is consistent with the finding that the two monoclonal antibodies react weakly with bacteroid LPS. It is concluded that methylation changes occur on the LPS O-chain of R. leguminosarum bv. phaseoli when the bacteria are grown at low pH and during nodule development.
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Affiliation(s)
- U R Bhat
- Complex Carbohydrate Research Center, University of Georgia, Athens 30602
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Tao H, Brewin NJ, Noel KD. Rhizobium leguminosarum CFN42 lipopolysaccharide antigenic changes induced by environmental conditions. J Bacteriol 1992; 174:2222-9. [PMID: 1312998 PMCID: PMC205842 DOI: 10.1128/jb.174.7.2222-2229.1992] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Four monoclonal antibodies were raised against the lipopolysaccharide of Rhizobium leguminosarum bv. phaseoli CFN42 grown in tryptone and yeast extract. Two of these antibodies reacted relatively weakly with the lipopolysaccharide of bacteroids of this strain isolated from bean nodules. Growth ex planta of strain CFN42 at low pH, high temperature, low phosphate, or low oxygen concentration also eliminated binding of one or both of these antibodies. Lipopolysaccharide mobility on gel electrophoresis and reaction with other monoclonal antibodies and polyclonal antiserum indicated that the antigenic changes detected by these two antibodies did not represent major changes in lipopolysaccharide structure. The antigenic changes at low pH were dependent on growth of the bacteria but were independent of nitrogen and carbon sources and the rich or minimal quality of the medium. The Sym plasmid of this strain was not required for the changes induced ex planta. Analysis of bacterial mutants inferred to have truncated O-polysaccharides indicated that part, but not all, of the lipopolysaccharide O-polysaccharide portion was required for binding of these two antibodies. In addition, this analysis suggested that O-polysaccharide structures more distal to lipid A than the epitopes themselves were required for the modifications at low pH that prevented antibody binding. Two mutants were antigenically abnormal, even though they had abundant lipopolysaccharides of apparently normal size. One of these two mutants was constitutively unreactive toward three of the antibodies but indistinguishable from the wild type in symbiotic behavior. The other, whose bacteroids retained an epitope normally greatly diminished in bacteroids, was somewhat impaired in nodulation frequency and nodule development.
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Affiliation(s)
- H Tao
- Department of Biology, Marquette University, Milwaukee, Wisconsin 53233
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Perotto S, Malavasi F, Butcher GW. 12 Use of Monoclonal Antibodies to Study Mycorrhiza: Present Applications and Perspectives. J Microbiol Methods 1992. [DOI: 10.1016/s0580-9517(08)70095-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
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Bhat UR, Krishnaiah BS, Carlson RW. Re-examination of the structures of the lipopolysaccharide core oligosaccharides from Rhizobium leguminosarum biovar phaseoli. Carbohydr Res 1991; 220:219-27. [PMID: 1811857 DOI: 10.1016/0008-6215(91)80020-n] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- U R Bhat
- Complex Carbohydrate Research Center, University of Georgia, Athens 30602
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Abstract
lpsZ+ is an allele that allows exo (exopolysaccharide-deficient) mutants of Rhizobium meliloti to invade nodules by modifying rhizobial lipopolysaccharide. We have cloned and sequenced the lpsZ gene. The predicted LpsZ protein has a molecular weight of 48,589 and is probably localized in the cytoplasm. A beta-glucuronidase fusion in the lpsZ gene indicates that lpsZ is not regulated by oxygen or nitrogen.
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Affiliation(s)
- P M Brzoska
- Department of Biology, Massachusetts Institute of Technology, Cambridge 02139
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Carrion M, Bhat UR, Reuhs B, Carlson RW. Isolation and characterization of the lipopolysaccharides from Bradyrhizobium japonicum. J Bacteriol 1990; 172:1725-31. [PMID: 2318801 PMCID: PMC208662 DOI: 10.1128/jb.172.4.1725-1731.1990] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The lipopolysaccharide (LPS) of Bradyrhizobium japonicum 61A123 was isolated and partially characterized. Phenol-water extraction of strain 61A123 yielded LPS exclusively in the phenol phase. The water phase contained low-molecular-weight glucans and extracellular or capsular polysaccharides. The LPSs from B. japonicum 61A76, 61A135, and 61A101C were also extracted exclusively into the phenol phase. The LPSs from strain USDA 110 and its Nod- mutant HS123 were found in both the phenol and water phases. The LPS from strain 61A123 was further characterized by polyacrylamide gel electrophoresis, composition analysis, and 1H and 13C nuclear magnetic resonance spectroscopy. Analysis of the LPS by polyacrylamide gel electrophoresis showed that it was present in both high- and low-molecular-weight forms (LPS I and LPS II, respectively). Composition analysis was also performed on the isolated lipid A and polysaccharide portions of the LPS, which were purified by mild acid hydrolysis and gel filtration chromatography. The major components of the polysaccharide portion were fucose, fucosamine, glucose, and mannose. The intact LPS had small amounts of 2-keto-3-deoxyoctulosonic acid. Other minor components were quinovosamine, glucosamine, 4-O-methylmannose, heptose, and 2,3-diamino-2,3-dideoxyhexose. The lipid A portion of the LPS contained 2,3-diamino-2,3-dideoxyhexose as the only sugar component. The major fatty acids were beta-hydroxymyristic, lauric, and oleic acids. A long-chain fatty acid, 27-hydroxyoctacosanoic acid, was also present in this lipid A. Separation and analysis of LPS I and LPS II indicated that glucose, mannose, 4-O-methylmannose, and small amounts of 2,2-diamino-2,3-dideozyhexose and heptose were components of the core region of the LPS, whereas fucose, fucosmine, mannose, and small amounts of quinovosamine and glucosamine were components of the LPS O-chain region.
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Affiliation(s)
- M Carrion
- Complex Carbohydrate Research Center, University of Georgia, Athens 30602
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Sindhu SS, Brewin NJ, Kannenberg EL. Immunochemical analysis of lipopolysaccharides from free-living and endosymbiotic forms of Rhizobium leguminosarum. J Bacteriol 1990; 172:1804-13. [PMID: 2318803 PMCID: PMC208672 DOI: 10.1128/jb.172.4.1804-1813.1990] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Rhizobium leguminosarum B556 and 8002 differ only with respect to carrying symbiotic plasmids with specificity for Pisum or Phaseolus hosts, respectively. Protease-treated samples derived from free-living cultures of both strains revealed a ladder of lipopolysaccharide (LPS-1) bands after periodate-silver staining of sodium dodecyl sulfate-polyacrylamide gels. These bands were arranged as doublets. After Western (immuno-) blotting, all LPS-1 bands reacted with monoclonal antibody JIM 21, whereas monoclonal antibody MAC 57 reacted only with the upper (slower-migrating) band and monoclonal antibody MAC 114 reacted only with the lower band of each doublet pair. Preparations obtained from bacteroids of Pisum or Phaseolus nodules showed significant differences in the size distribution and antigenicity of LPS. In bacteroids from Phaseolus sp., JIM 21 and MAC 57 each stained a ladder of LPS-1 bands on sodium dodecyl sulfate-polyacrylamide gels which corresponded in mobility to the upper band of each doublet pair seen in free-living cultures. MAC 114 did not react with the LPS from Phaseolus sp.-derived bacteroids. In bacteroids from Pisum sp., only fast-migrating (lower-molecular-weight) forms of LPS-1 could be visualized on gels, but both upper and lower bands of each doublet were still present and could be stained by the appropriate monoclonal antibody, MAC 57 or MAC 114, respectively. Similarly, bacteroids from R. leguminosarum 3841, which nodulates Pisum species, differed with respect to the structure and antigenicity of their LPS-1 from bacteroids of a related strain, B625, which nodulates Phaseolus species. Physiological factors were investigated that could account for these differences between the structures of LPS-1 from free-living cultures of B556 and 8002 and that from bacteroids. The following modifications in growth conditions each tended to reduce the expression of MAC 114 antigen and enhance the expression of MAC 57 antigen: succinate rather than glucose as the carbon source; microaerobic (2.5%, vol/vol) oxygen concentrations; and acidic (pH 5 to 6) culture medium. When all three of these conditions were combined, the LPS-1 that resulted was very similar to that in bacteroids from Pisum nodules. However, it was not possible to reproduce the LPS-1 pattern observed for bacteroids from Phaseolus nodules, which maintained a ladder of LPS bands reacting with MAC 57 antibody.
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Affiliation(s)
- S S Sindhu
- John Innes Institute, AFRC Institute of Plant Science Research, Norwich, United Kingdom
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VandenBosch KA, Brewin NJ, Kannenberg EL. Developmental regulation of a Rhizobium cell surface antigen during growth of pea root nodules. J Bacteriol 1989; 171:4537-42. [PMID: 2768180 PMCID: PMC210247 DOI: 10.1128/jb.171.9.4537-4542.1989] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
A monoclonal antibody, AFRC MAC 203, was used to examine the expression of a nodule-induced cell surface antigen associated with lipopolysaccharide in Rhizobium leguminosarum bv. viciae 3841. Silver-enhanced immunogold-labeled tissue sections revealed that, in very young tissues of pea root nodules, the nodule-induced form of lipopolysaccharide antigen was not expressed either by rhizobia in the infection thread or by bacteria recently released into the plant cell cytoplasm. In the more mature regions of the nodule, the antigen was expressed by membrane-enclosed bacteroids, including immature forms that had not yet expressed the enzyme nitrogenase and were not yet Y shaped. Immunogold labeling of thin sections revealed that the MAC 203 antigen, but not the nitrogenase, was also expressed by bacteria in infection threads situated in and between bacteroid-containing plant cells in mature nodule tissue.
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Wood EA, Butcher GW, Brewin NJ, Kannenberg EL. Genetic derepression of a developmentally regulated lipopolysaccharide antigen from Rhizobium leguminosarum 3841. J Bacteriol 1989; 171:4549-55. [PMID: 2768182 PMCID: PMC210249 DOI: 10.1128/jb.171.9.4549-4555.1989] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Monoclonal antibody AFRC MAC 203 recognizes a developmentally regulated lipopolysaccharide antigen in Rhizobium leguminosarum bv. viciae 3841. Transposon-induced mutants that constitutively expressed MAC 203 antigen were isolated. These strains were morphologically normal, showed no gross abnormalities in lipopolysaccharide size distribution on sodium dodecyl sulfate-polyacrylamide gels, and induced normal nitrogen-fixing nodules. However, the mutants lacked lipopolysaccharide epitopes recognized by another rat monoclonal antibody, AFRC MAC 281, suggesting that the corresponding epitopes may be interconverted or share a common precursor. In conjugational crosses, the transposon insertion associated with both the loss of MAC 281 antigen and the constitutive expression of MAC 203 antigen showed linkage to the chromosomal rif allele. A derivative of strain 3841 with a deletion spanning the nod-fix region of the symbiotic plasmid showed no altered expression pattern for MAC 203 antigen, suggesting that the relevant genetic determinants map to genomic sites that are not associated with nifA or any known genes on the symbiotic plasmid.
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Affiliation(s)
- E A Wood
- John Innes Institute, Norwich, United Kingdom
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