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Manuel Megias - One of the best experts on this subject based on the ideXlab platform.
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The Rhizobium tropici CIAT 899 NodD2 protein regulates the production of Nod Factors under salt stress in a flavonoid-independent manner.
Scientific reports, 2017Co-Authors: Pablo Del Cerro, Manuel Megias, Antonio M. Gil-serrano, Francisco Pérez-montaño, Francisco Javier López-baena, Mariangela Hungria, Francisco Javier OlleroAbstract:In the symbiotic associations between rhizobia and legumes, NodD promotes the expression of the Nodulation genes in the presence of appropriate flavonoids. This set of genes is implied in the synthesis of Nodulation Factors, which are responsible for launching the Nodulation process. Rhizobium tropici CIAT 899 is the most successful symbiont of Phaseolus vulgaris and can nodulate a variety of legumes. This strain produces Nodulation Factors under abiotic stress such as acidity or high concentration of salt. Genome sequencing of CIAT 899 allowed the identification of five nodD genes. Whereas NodD1 is essential to nodulate Leucaena leucocephala, Lotus japonicus and Macroptilium atropurpureum, symbiosis with P. vulgaris and Lotus burtii decreased the nodule number but did not abolish the symbiotic process when NodD1 is absent. Nodulation Factor synthesis under salt stress is not regulated by NodD1. Here we confirmed that NodD2 is responsible for the activation of the CIAT 899 symbiotic genes under salt stress. We have demonstrated that NodD1 and NodD2 control the synthesis of the Nod Factor necessary for a successful symbiosis with P. vulgaris and L. burtii. This is the first time that NodD is directly implied in the activation of the symbiotic genes under an abiotic stress.
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effect of azospirillum brasilense coinoculated with rhizobium on phaseolus vulgaris flavonoids and nod Factor production under salt stress
Soil Biology & Biochemistry, 2008Co-Authors: Marta S Dardanelli, Francisco Fernandez J De Cordoba, Rosario M Espuny, Miguel Angel Rodriguez Carvajal, Maria Soria E Diaz, Antonio Miguel Gil Serrano, Yaacov Okon, Manuel MegiasAbstract:The effects of salt upon Azospirillum brasilense strain Cd on plant growth, Nodulation, flavonoid and lipochitooligosaccharide (LCOs-Nod Factor) production, were sequentially followed after 4, 7 and 14 days during a Rhizobium-Phaseolus vulgaris cv. Negro Jamapa interaction, in a hydroponics growth system. Azospirillum brasilense promoted root branching in bean seedling roots and increased secretion of nod-gene-inducing flavonoid species, as detected by high-performance liquid chromatography (HPLC). The results also support that A. brasilense allows a longer, more persistent exudation of flavonoids by bean roots. A general positive effect of Azospirillum-Rhizobium coinoculation on the expression of nod-genes by Rhizobium tropici CIAT899 and Rhizobium etli ISP42, and on Nodulation Factor patterns, was observed in the presence of root exudates. The negative effects obtained under salt stress on nod-gene expression and on Nod Factors' appearance were relieved in coinoculated plants.
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Low pH Changes the Profile of Nodulation Factors Produced by Rhizobium tropici CIAT899
Chemistry & biology, 2005Co-Authors: Belén Morón, Manuel Megias, María Eugenia Soria-díaz, James R. Ault, George P. Verroios, Sadaf Noreen, Dulce N. Rodríguez-navarro, Antonio M. Gil-serrano, Jane Thomas-oates, Carolina SousaAbstract:Rhizobium tropici CIAT899 has been cataloged as a nodulator of bean, a plant often growing in areas characterized by highly acidic soils. The purpose of this work was to explore the effects of acidity on the production of Nod Factors by this strain and their impact on the establishment of effective symbioses. We report that acidity increases rhizobial Nod Factors production, and we exhaustively study the Nodulation Factor structures produced under abiotic stress. Significant differences were observed between the structures produced at acid and neutral pH: 52 different molecules were produced at acid pH, 29 at neutral pH, and only 15 are common to bacteria grown at pH 7.0 or 4.5. The results indicate that R. tropici CIAT899 has successfully adapted to life in acidic soils and is a good inoculant for the bean under these conditions.
Michael John - One of the best experts on this subject based on the ideXlab platform.
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Biosynthesis of lipooligosaccharide Nodulation Factors: Rhizobium NodA protein is involved in N-acylation of the chitooligosaccharide backbone (nitrogen fixation/common nod genes/Rhizobium meliloti)
2016Co-Authors: Horst Röhrig, Jürgen Schmidt, Ursula Wieneke, Jeff Schell, Michael JohnAbstract:Rhizobium meliloti interacts symbiotically with alfalfa by forming root nodules in which the bacteria fix nitrogen. The Rhizobium Nodulation genes nodABC are in- volved in the synthesis of lipooligosaccharide symbiotic signal molecules, which are mono-N-acylated chitooligosaccharides. These bacterial signals elicit nodule organogenesis in roots of legumes. To elucidate the role of the NodA protein in lipooli- gosaccharide biosynthesis, we prepared a radiolabeled tet- rasaccharide precursor carrying an amino group as a potential attachment site for N-acylation at the nonreducing glucosamine residue. Various criteria demonstrate that NodA is involved in the attachment of a fatty acyl chain to this tetrasaccharide precursor, yielding a biologically active Nodulation Factor.
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Microspectroscopic imaging of Nodulation Factor-binding sites on living Vicia sativa roots using a novel bioactive fluorescent Nodulation Factor
Biophysical journal, 1997Co-Authors: Th.w.j. Gadella, Michael John, György Vereb, A. E. Hadri, H. Rohrig, J. Schmidt, J. Schell, T. BisselingAbstract:A novel bioactive fluorescent Nodulation (Nod) Factor, NodRlv-IV(BODIPY FL-C16), has been synthesized by attaching a BODIPY FL-C16 acyl chain to the primary amino group of chitotetraose deacetylated at the nonreducing terminus by recombinant NodB. The binding of the fluorescent Nod Factor to root systems of Vicia sativa was investigated with fluorescence spectral imaging microscopy (FSPIM) and fluorescence ratio imaging microscopy (FRIM). Spatially resolved fluorescence spectra of living and labeled Vicia sativa root systems were measured by FSPIM. Strong autofluorescence, inherent to many plant systems when excited at 488 nm, was corrected for by utilizing the difference in fluorescence emission spectra of the autofluorescence and NodRlv-IV(BODIPY FL-C16). A methodology is presented to break down the in situ fluorescence emission spectra into spatially resolved autofluorescence and BODIPY FL fluorescence spectra. Furthermore, an FRIM method was developed for correcting autofluorescence in fluorescence micrographs for this system. After autofluorescence correction it was shown that NodRlv-IV(BODIPY FL-C16) was concentrated in the root hairs, but was also bound to other parts of the root surface.
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Biosynthesis of lipooligosaccharide Nodulation Factors: Rhizobium NodA protein is involved in N-acylation of the chitooligosaccharide backbone.
Proceedings of the National Academy of Sciences of the United States of America, 1994Co-Authors: Horst Röhrig, Jürgen Schmidt, Ursula Wieneke, Eva Kondorosi, Isabelle Barlier, Jeff Schell, Michael JohnAbstract:Rhizobium meliloti interacts symbiotically with alfalfa by forming root nodules in which the bacteria fix nitrogen. The Rhizobium Nodulation genes nodABC are involved in the synthesis of lipooligosaccharide symbiotic signal molecules, which are mono-N-acylated chitooligosaccharides. These bacterial signals elicit nodule organogenesis in roots of legumes. To elucidate the role of the NodA protein in lipooligosaccharide biosynthesis, we prepared a radiolabeled tetrasaccharide precursor carrying an amino group as a potential attachment site for N-acylation at the nonreducing glucosamine residue. Various criteria demonstrate that NodA is involved in the attachment of a fatty acyl chain to this tetrasaccharide precursor, yielding a biologically active Nodulation Factor.
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Rhizobium NodB protein involved in Nodulation signal synthesis is a chitooligosaccharide deacetylase
Proceedings of the National Academy of Sciences of the United States of America, 1993Co-Authors: Michael John, Horst Röhrig, Ursula Wieneke, Jurgen G. Schmidt, Jeff SchellAbstract:The common Nodulation genes nodABC are conserved in all rhizobia and are involved in synthesis of a lipooligosaccharide signal molecule. This bacterial signal consists of a chitooligosaccharide backbone, which carries at the nonreducing end a fatty acyl chain. The modified chitooligosaccharide molecule triggers development of nodules on the roots of the leguminous host plant. To elucidate the specific role of the NodB protein in Nodulation Factor synthesis, we have purified recombinant NodB and determined its biochemical role by direct assays. Our data show that the NodB protein of Rhizobium meliloti deacetylates the nonreducing N-acetylglucosamine residue of chitooligosaccharides. The monosaccharide N-acetylglucosamine is not deacetylated by NodB. In the pathway of Nod Factor synthesis, deacetylation at the nonreducing end of the oligosaccharide backbone may be a necessary requirement for attachment of the fatty acyl chain.
Jean-jacques Bono - One of the best experts on this subject based on the ideXlab platform.
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The DMI1 and DMI2 early symbiotic genes of Medicago truncatula are required for a high-affinity Nodulation Factor-binding site associated to a particulate fraction of roots
Plant Physiology, 2006Co-Authors: Bridget V. Hogg, Raoul Ranjeva, Julie V. Cullimore, Jean-jacques BonoAbstract:The establishment of the legume-rhizobia symbiosis between Medicago spp. and Sinorhizobium meliloti is dependent on the production of sulfated lipo-chitooligosaccharidic Nodulation (Nod) Factors by the bacterial partner. In this article, using a biochemical approach to characterize putative Nod Factor receptors in the plant host, we describe a high-affinity binding site (Kd = 0.45 nM) for the major Nod Factor produced by S. meliloti. This site is termed Nod Factor-binding site 3 (NFBS3). NFBS3 is associated to a high-density fraction prepared from roots of Medicago truncatula and shows binding specificity for lipo-chitooligosaccharidic structures. As for the previously characterized binding sites (NFBS1 and NFBS2), NFBS3 does not recognize the sulfate group on the S. meliloti Nod Factor. Studies of Nod Factor binding in root extracts of early symbiotic mutants of M. truncatula reveals that the new site is present in Nod Factor perception and does not make infections 3 (dmi3) mutants but is absent in dmi1 and dmi2 mutants. Roots and cell cultures of all these mutants still contain sites similar to NFBS1 and NFBS2, respectively. These results suggest that NFBS3 is different from NFBS2 and NFBS1 and is dependent on the common symbiotic genes DMI1 and DMI2 required for establishment of symbioses with both rhizobia and arbuscular mycorrhizal fungi. The potential role of this site in the establishment of root endosymbioses is discussed.
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Rapid colorimetric quantification of lipo-chitooligosaccharides from Mesorhizobium loti and Sinorhizobium meliloti.
Molecular Plant-microbe Interactions, 2002Co-Authors: Joachim Goedhart, Jean-jacques Bono, Theodorus W. J. GadellaAbstract:Nod Factors are lipids with a chitinlike headgroup produced by gram-negative Rhizobium bacteria. These lipo-chitooligosaccharides (LCOs) are essential signaling molecules for accomplishing symbiosis between the bacteria and roots of legume plants. Despite their important role in the Rhizobium-legume interaction, no fast and sensitive Nod Factor quantification methods exist. Here, we report two different quantification methods. The first is based on the enzymatic hydrolysis of Nod Factors to release N-acetylglucosamine (GlcNAc), which can subsequently be quantified. It is shown that the degrading enzyme, glusulase, releases exactly two GlcNAc units per pentameric Nodulation Factor from Mesorhizobium loti Factor, allowing quantification of LCOs from Mesorhizobium loti. The second method is based on a specific type of Nod Factors that are sulfated on the reducing GlcNAc, allowing quantification analogous to the quantification of sulfolipids. Here, a two-phase extraction method is used in the presence of meth...
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Rapid colorimetric quantification of lipo-chitooligosaccharides from Mesorhizobium loti and Sinorhizobium meliloti
Molecular Plant-Microbe Interactions, 2002Co-Authors: Joachim Goedhart, Jean-jacques Bono, Theodorus W. J. GadellaAbstract:Nod Factors are lipids with a chitinlike headgroup produced by gram-negative Rhizobium bacteria. These lipo-chitooligosaccharides (LCOs) are essential signaling molecules for accomplishing symbiosis between the bacteria and roots of legume plants. Despite their important role in the Rhizobium-legume interaction, no fast and sensitive Nod Factor quantification methods exist. Here, we report two different quantification methods. The first is based on the enzymatic hydrolysis of Nod Factors to release N-acetylglucosamine (GlcNAc), which can subsequently be quantified. It is shown that the degrading enzyme, glusulase, releases exactly two GlcNAc units per pentameric Nodulation Factor from Mesorhizobium loti Factor, allowing quantification of LCOs from Mesorhizobium loti. The second method is based on a specific type of Nod Factors that are sulfated on the reducing GlcNAc, allowing quantification analogous to the quantification of sulfolipids. Here, a two-phase extraction method is used in the presence of methylene blue, which specifically forms an ion pair with sulfated lipids. The blue ion pair partitions into the organic phase, after which the methylene blue signal can be quantified. To enable Nod Factor quantification with this method, the organic phase was modified and the partitioning was evaluated using fluorescent and radiolabeled sulfated Nod Factors. It is shown that sulfated LCOs can be quantified with this method, using sodium dodecyl sulfate for calibration. Both methods allow Nod Factor quantification in parallel enabling a fast and easy detection of nanomole quantities of Nod Factors. Accurate Nod Factor quantification will be crucial for characterization and cross-comparison of the affinity for Nod Factors of newly identified Nod Factor binding proteins or putative Nod Factor receptors.
Anne Mie C. Emons - One of the best experts on this subject based on the ideXlab platform.
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a nonsymbiotic root hair tip growth phenotype in nork mutated legumes implications for Nodulation Factor induced signaling and formation of a multifaceted root hair pocket for bacteria
The Plant Cell, 2004Co-Authors: John J. Esseling, Franck Lhuissier, Anne Mie C. EmonsAbstract:The Medicago truncatula Does not Make Infections (DMI2) mutant is mutated in the Nodulation receptor-like kinase, NORK. Here, we report that NORK-mutated legumes of three species show an enhanced touch response to experimental handling, which results in a nonsymbiotic root hair phenotype. When care is taken not to induce this response, DMI2 root hairs respond morphologically like the wild type to Nodulation Factor (NF). Global NF application results in root hair deformation, and NF spot application induces root hair reorientation or branching, depending on the position of application. In the presence of Sinorhizobium meliloti, DMI2 root hairs make two-dimensional 180° curls but do not entrap bacteria in a three-dimensional pocket because curling stops when the root hair tip touches its own shank. Because DMI2 does not express the promoter of M. truncatula Early Nodulin11 (ENOD11) coupled to β-glucuronidase upon NF application, we propose a split in NF-induced signaling, with one branch to root hair curling and the other to ENOD11 expression.
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A Nonsymbiotic Root Hair Tip Growth Phenotype in NORK-Mutated Legumes: Implications for Nodulation Factor–Induced Signaling and Formation of a Multifaceted Root Hair Pocket for Bacteria
The Plant cell, 2004Co-Authors: John J. Esseling, Franck Lhuissier, Anne Mie C. EmonsAbstract:The Medicago truncatula Does not Make Infections (DMI2) mutant is mutated in the Nodulation receptor-like kinase, NORK. Here, we report that NORK-mutated legumes of three species show an enhanced touch response to experimental handling, which results in a nonsymbiotic root hair phenotype. When care is taken not to induce this response, DMI2 root hairs respond morphologically like the wild type to Nodulation Factor (NF). Global NF application results in root hair deformation, and NF spot application induces root hair reorientation or branching, depending on the position of application. In the presence of Sinorhizobium meliloti, DMI2 root hairs make two-dimensional 180° curls but do not entrap bacteria in a three-dimensional pocket because curling stops when the root hair tip touches its own shank. Because DMI2 does not express the promoter of M. truncatula Early Nodulin11 (ENOD11) coupled to β-glucuronidase upon NF application, we propose a split in NF-induced signaling, with one branch to root hair curling and the other to ENOD11 expression.
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lipochito oligosaccharide Nodulation Factors stimulate cytoplasmic polarity with longitudinal endoplasmic reticulum and vesicles at the tip in vetch root hairs
Molecular Plant-microbe Interactions, 2000Co-Authors: Deborah D Miller, Hetty Leferinkten B Klooster, Anne Mie C. EmonsAbstract:Vetch root hair development has four stages: bulge, growing, growth terminating, and full-grown hair. In the assay we used, the Nodulation Factor induced swellings and outgrowths in growth-terminating hairs. Bulges, swellings, and full-grown hairs have transverse endoplasmic reticulum (ER) and no tip-accumulated vesicles. Growing hairs and outgrowths show vesicle accumulation in the tip and longitudinal subapical ER. Bulge walls and walls of swellings appear mottled.
Theodorus W. J. Gadella - One of the best experts on this subject based on the ideXlab platform.
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Rapid colorimetric quantification of lipo-chitooligosaccharides from Mesorhizobium loti and Sinorhizobium meliloti.
Molecular Plant-microbe Interactions, 2002Co-Authors: Joachim Goedhart, Jean-jacques Bono, Theodorus W. J. GadellaAbstract:Nod Factors are lipids with a chitinlike headgroup produced by gram-negative Rhizobium bacteria. These lipo-chitooligosaccharides (LCOs) are essential signaling molecules for accomplishing symbiosis between the bacteria and roots of legume plants. Despite their important role in the Rhizobium-legume interaction, no fast and sensitive Nod Factor quantification methods exist. Here, we report two different quantification methods. The first is based on the enzymatic hydrolysis of Nod Factors to release N-acetylglucosamine (GlcNAc), which can subsequently be quantified. It is shown that the degrading enzyme, glusulase, releases exactly two GlcNAc units per pentameric Nodulation Factor from Mesorhizobium loti Factor, allowing quantification of LCOs from Mesorhizobium loti. The second method is based on a specific type of Nod Factors that are sulfated on the reducing GlcNAc, allowing quantification analogous to the quantification of sulfolipids. Here, a two-phase extraction method is used in the presence of meth...
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Rapid colorimetric quantification of lipo-chitooligosaccharides from Mesorhizobium loti and Sinorhizobium meliloti
Molecular Plant-Microbe Interactions, 2002Co-Authors: Joachim Goedhart, Jean-jacques Bono, Theodorus W. J. GadellaAbstract:Nod Factors are lipids with a chitinlike headgroup produced by gram-negative Rhizobium bacteria. These lipo-chitooligosaccharides (LCOs) are essential signaling molecules for accomplishing symbiosis between the bacteria and roots of legume plants. Despite their important role in the Rhizobium-legume interaction, no fast and sensitive Nod Factor quantification methods exist. Here, we report two different quantification methods. The first is based on the enzymatic hydrolysis of Nod Factors to release N-acetylglucosamine (GlcNAc), which can subsequently be quantified. It is shown that the degrading enzyme, glusulase, releases exactly two GlcNAc units per pentameric Nodulation Factor from Mesorhizobium loti Factor, allowing quantification of LCOs from Mesorhizobium loti. The second method is based on a specific type of Nod Factors that are sulfated on the reducing GlcNAc, allowing quantification analogous to the quantification of sulfolipids. Here, a two-phase extraction method is used in the presence of methylene blue, which specifically forms an ion pair with sulfated lipids. The blue ion pair partitions into the organic phase, after which the methylene blue signal can be quantified. To enable Nod Factor quantification with this method, the organic phase was modified and the partitioning was evaluated using fluorescent and radiolabeled sulfated Nod Factors. It is shown that sulfated LCOs can be quantified with this method, using sodium dodecyl sulfate for calibration. Both methods allow Nod Factor quantification in parallel enabling a fast and easy detection of nanomole quantities of Nod Factors. Accurate Nod Factor quantification will be crucial for characterization and cross-comparison of the affinity for Nod Factors of newly identified Nod Factor binding proteins or putative Nod Factor receptors.