scholarly journals Sinorhizobium fredii HH103 Invades Lotus burttii by Crack Entry in a Nod Factor–and Surface Polysaccharide–Dependent Manner

2016 ◽  
Vol 29 (12) ◽  
pp. 925-937 ◽  
Author(s):  
Sebastián Acosta-Jurado ◽  
Dulce-Nombre Rodríguez-Navarro ◽  
Yasuyuki Kawaharada ◽  
Juan Fernández Perea ◽  
Antonio Gil-Serrano ◽  
...  
Keyword(s):  
Root Hairs ◽  
Broad Host Range ◽  
Capsular Polysaccharides ◽  
Dependent Manner ◽  
Nod Factors ◽  
Sinorhizobium Fredii ◽  
Nod Factor ◽  
Mesorhizobium Loti ◽  
Infection Threads ◽  
Surface Polysaccharide

Sinorhizobium fredii HH103-Rifr, a broad host range rhizobial strain, induces nitrogen-fixing nodules in Lotus burttii but ineffective nodules in L. japonicus. Confocal microscopy studies showed that Mesorhizobium loti MAFF303099 and S. fredii HH103-Rifr invade L. burttii roots through infection threads or epidermal cracks, respectively. Infection threads in root hairs were not observed in L. burttii plants inoculated with S. fredii HH103-Rifr. A S. fredii HH103-Rifr nodA mutant failed to nodulate L. burttii, demonstrating that Nod factors are strictly necessary for this crack-entry mode, and a noeL mutant was also severely impaired in L. burttii nodulation, indicating that the presence of fucosyl residues in the Nod factor is symbiotically relevant. However, significant symbiotic impacts due to the absence of methylation or to acetylation of the fucosyl residue were not detected. In contrast S. fredii HH103-Rifr mutants showing lipopolysaccharide alterations had reduced symbiotic capacity, while mutants affected in production of either exopolysaccharides, capsular polysaccharides, or both were not impaired in nodulation. Mutants unable to produce cyclic glucans and purine or pyrimidine auxotrophic mutants formed ineffective nodules with L. burttii. Flagellin-dependent bacterial mobility was not required for crack infection, since HH103-Rifr fla mutants nodulated L. burttii. None of the S. fredii HH103-Rifr surface-polysaccharide mutants gained effective nodulation with L. japonicus.

scholarly journals A plant chitinase controls cortical infection thread progression and nitrogen-fixing symbiosis

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Anna Malolepszy ◽  
Simon Kelly ◽  
Kasper Kildegaard Sørensen ◽  
Euan Kevin James ◽  
Christina Kalisch ◽  
...  
Keyword(s):  
Root Nodules ◽  
Lotus Japonicus ◽  
Positional Information ◽  
Dependent Manner ◽  
Nitrogen Fixing ◽  
Nod Factors ◽  
Nod Factor ◽  
Infection Threads ◽  
Bacterial Mutants ◽  
Multicellular Organisms

Morphogens provide positional information and their concentration is key to the organized development of multicellular organisms. Nitrogen-fixing root nodules are unique organs induced by Nod factor-producing bacteria. Localized production of Nod factors establishes a developmental field within the root where plant cells are reprogrammed to form infection threads and primordia. We found that regulation of Nod factor levels by Lotus japonicus is required for the formation of nitrogen-fixing organs, determining the fate of this induced developmental program. Our analysis of plant and bacterial mutants shows that a host chitinase modulates Nod factor levels possibly in a structure-dependent manner. In Lotus, this is required for maintaining Nod factor signalling in parallel with the elongation of infection threads within the nodule cortex, while root hair infection and primordia formation are not influenced. Our study shows that infected nodules require balanced levels of Nod factors for completing their transition to functional, nitrogen-fixing organs.

scholarly journals Rhizobium Nod Factors Induce an Increase in Sub-apical Fine Bundles of Actin Filaments in Vicia sativa Root Hairs within Minutes

1999 ◽  
Vol 12 (9) ◽  
pp. 829-832 ◽  
Author(s):  
Norbert C. A. de Ruijter ◽  
Ton Bisseling ◽  
Anne Mie C. Emons
Keyword(s):  
Actin Cytoskeleton ◽  
Actin Filaments ◽  
Tip Growth ◽  
Developmental Stages ◽  
Root Hairs ◽  
Vicia Sativa ◽  
Nod Factors ◽  
Nod Factor

We studied the response of the actin cytoskeleton in vetch root hairs after application of host-specific Nod factor. Within 3 to 15 min, the number of sub-apical fine bundles of actin filaments (FB-actin) increased in all developmental stages. Tip growth resumed only in hairs in which the FB-actin density and the length of the region with FB-actin exceeded a minimal value.

Regulation of Nod factor sulphation genes in Rhizobium tropici CIAT899

2001 ◽  
Vol 47 (6) ◽  
pp. 574-579 ◽  
Author(s):  
Hamid Manyani ◽  
Carolina Sousa ◽  
María-Eugenia Soria Díaz ◽  
Antonio Gil-Serrano ◽  
Manuel Megías
Keyword(s):  
Wide Spectrum ◽  
Constitutive Expression ◽  
Upstream Region ◽  
Broad Host Range ◽  
Nod Factors ◽  
Rhizobium Tropici ◽  
Free Living ◽  
Nod Factor ◽  
Symbiotic Plasmid ◽  
Transcriptional Fusions

Rhizobium tropici CIAT899 is a tropical symbiont able to nodulate various legumes such as Leucaena, Phaseolus, and Macroptilium. Broad host range of this species is related to its Nod factors wide spectrum. R. tropici contains Nod factors sulphation nod genes, nodHPQ genes, which control nodulation efficiency in Leucaena. To study nodHPQ regulation, we carried out different interposon insertions in its upstream region. One of these generated interruptions, nodI mutant produced nonsulphated Nod factors suggesting a possible dependence of these genes on nodI upstream region. Moreover, analysis results of lacZ transcriptional fusions with these genes in symbiotic plasmid showed dependence of these genes on NodD protein. In order to determine nodHPQ organization, we studied the effect of interposon insertion upstream of each lacZ transcriptional fusion, and the data obtained was used to indicate that nodHPQ belong to the nodABCSUIJ operon. However, comparison between nodP::lacZ β-galactosidase activity in the symbiotic plasmid and in the pHM500 plasmid (containing nodHPQ genes) suggested constitutive expression in free living, and flavonoid inducible expression in symbiotic conditions. Constitutive nodHPQ expression may play a role in bacterial house-keeping metabolism. On the other hand, the transference of R. tropici nodHPQ genes to other rhizobia that do not present sulphated substitutions demonstrated that NodH protein sulphotransference is specific to C6 at the reducing end.Key words: Nod factors, nodHPQ genes, Rhizobium tropici, nod-box.

scholarly journals Identical Accumulation and Immobilization of Sulfated and Nonsulfated Nod Factors in Host and Nonhost Root Hair Cell Walls

2003 ◽  
Vol 16 (10) ◽  
pp. 884-892 ◽  
Author(s):  
Joachim Goedhart ◽  
Jean-Jacques Bono ◽  
Ton Bisseling ◽  
Theodorus W. J. Gadella
Keyword(s):  
Hair Cell ◽  
Root Hair ◽  
Cell Walls ◽  
Root Hairs ◽  
Sharp Decrease ◽  
Biologically Active ◽  
Nod Factors ◽  
Nod Factor ◽  
Root Hair Cell ◽  
Root Hair Deformation

Nod factors are signaling molecules secreted by Rhizobium bacteria. These lipo-chitooligosaccharides (LCOs) are required for symbiosis with legumes and can elicit specific responses at subnanomolar concentrations on a compatible host. How plants perceive LCOs is unclear. In this study, using fluorescent Nod factor analogs, we investigated whether sulfated and nonsulfated Nod factors were bound and perceived differently by Medicago truncatula and Vicia sativa root hairs. The bioactivity of three novel sulfated fluorescent LCOs was tested in a root hair deformation assay on M. truncatula, showing bioactivity down to 0.1 to 1 nM. Fluorescence microscopy of plasmolyzed M. truncatula root hairs shows that sulfated fluorescent Nod factors accumulate in the cell wall of root hairs, whereas they are absent from the plasma membrane when applied at 10 nM. When the fluorescent Nod factor distribution in medium surrounding a root was studied, a sharp decrease in fluorescence close to the root hairs was observed, visualizing the remarkable capacity of root hairs to absorb Nod factors from the medium. Fluorescence correlation microscopy was used to study in detail the mobilities of sulfated and nonsulfated fluorescent Nod factors which are biologically active on M. truncatula and V. sativa, respectively. Remarkably, no difference between sulfated and nonsulfated Nod factors was observed: both hardly diffuse and strongly accumulate in root hair cell walls of both M. truncatula and V. sativa. The implications for the mode of Nod factor perception are discussed.

scholarly journals Induction of Chalcone Synthase Expression by Rhizobia and Nod factors in Root Hairs and Roots

1997 ◽  
Vol 10 (3) ◽  
pp. 388-393 ◽  
Author(s):  
Andrea Krause ◽  
Vo T. T. Lan ◽  
William J. Broughton
Keyword(s):  
Chalcone Synthase ◽  
Root Hairs ◽  
Signal Transduction Pathway ◽  
Defense Responses ◽  
Nod Factors ◽  
Nod Factor ◽  
Transcript Levels ◽  
Gene Transcripts ◽  
Infection Pathway ◽  
Rhizobium Sp

Chalcone synthase (CHS) of Vigna unguiculata is encoded by a gene family that is abundantly transcribed in leaves and nodules. Inoculation with Rhizobium sp. NGR234, which nodulates V. unguiculata, or with NGRΔnodABC, a mutant deficient in Nod factor production, induced rapid accumulation of CHS mRNAs in roots and root hairs. As both Nod+ and Nod- bacteria provoke responses, induction of CHS gene expression may involve symbiotic or defense responses. Four days after inoculation with the wild-type Rhizobium sp., the transcript levels increased in roots but decreased in root hairs. Use of a region unique to the 5′ end of a specific CHS gene (VuCHS1) showed that increases of transcript levels in root hairs 24 h after inoculation with both rhizobia were specific to this gene. Transcripts of this gene in roots were only detectable 4 days after treatment with NGR234. It is possible therefore that accumulation of VuCHS1 follows the infection pathway of rhizobia entering legume roots. Purified Nod factors induced accumulation of transcripts, showing that they might be part of the signal transduction pathway leading to CHS expression.

scholarly journals Evidence for the Involvement in Nodulation of the Two Small Putative Regulatory Peptide-Encoding Genes MtRALFL1 and MtDVL1

2008 ◽  
Vol 21 (8) ◽  
pp. 1118-1127 ◽  
Author(s):  
Jean-Philippe Combier ◽  
Helge Küster ◽  
Etienne-Pascal Journet ◽  
Natalija Hohnjec ◽  
Pascal Gamas ◽  
...  
Keyword(s):  
Nodule Development ◽  
Strong Increase ◽  
Nod Factors ◽  
Plant Host ◽  
Symbiotic Interaction ◽  
Nod Factor ◽  
Infection Threads ◽  
Genes Encoding ◽  
Supernodulating Mutant ◽  
Increased Sensitivity

Nod factors are key bacterial signaling molecules regulating the symbiotic interaction between bacteria known as rhizobia and leguminous plants. Studying plant host genes whose expression is affected by Nod factors has given insights into early symbiotic signaling and development. Here, we used a double supernodulating mutant line that shows increased sensitivity to Nod factors to study the Nod factor-regulated transcriptome. Using microarrays containing more than 16,000 70-mer oligonucleotide probes, we identified 643 Nod-factor-regulated genes, including 225 new Nod-factor-upregulated genes encoding many potential regulators. Among the genes found to be Nod factor upregulated, we identified and characterized MtRALFL1 and MtDVL1, which code for two small putative peptide regulators of 135 and 53 amino acids, respectively. Expression analysis confirmed that these genes are upregulated during initial phases of nodulation. Overexpression of MtRALFL1 and MtDVL1 in Medicago truncatula roots resulted in a marked reduction in the number of nodules formed and in a strong increase in the number of aborted infection threads. In addition, abnormal nodule development was observed when MtRALFL1 was overexpressed. This work provides evidence for the involvement of new putative small-peptide regulators during nodulation.

scholarly journals Nod Factor Perception During Infection Thread Growth Fine-Tunes Nodulation

2007 ◽  
Vol 20 (2) ◽  
pp. 129-137 ◽  
Author(s):  
Jeroen Den Herder ◽  
Celine Vanhee ◽  
Riet De Rycke ◽  
Viviana Corich ◽  
Marcelle Holsters ◽  
...  
Keyword(s):  
Light And Electron Microscopy ◽  
Cortical Cell ◽  
Root Hairs ◽  
Infection Thread ◽  
Bacterial Invasion ◽  
Nodule Formation ◽  
Nodulation Factors ◽  
Polysaccharide Synthesis ◽  
Infection Threads ◽  
Surface Polysaccharide

Bacterial nodulation factors (NFs) are essential signaling molecules for the initiation of a nitrogen-fixing symbiosis in legumes. NFs are perceived by the plant and trigger both local and distant responses, such as curling of root hairs and cortical cell divisions. In addition to their requirement at the start, NFs are produced by bacteria that reside within infection threads. To analyze the role of NFs at later infection stages, several phases of nodulation were studied by detailed light and electron microscopy after coinoculation of adventitious root primordia of Sesbania rostrata with a mixture of Azorhizobium caulinodans mutants ORS571-V44 and ORS571-X15. These mutants are deficient in NF production or surface polysaccharide synthesis, respectively, but they can complement each other, resulting in functional nodules occupied by ORS571-V44. The lack of NFs within the infection threads was confirmed by the absence of expression of an early NF-induced marker, leghemoglobin 6 of S. rostrata. NF production within the infection threads is shown to be necessary for proper infection thread growth and for synchronization of nodule formation with bacterial invasion. However, local production of NFs by bacteria that are taken up by the plant cells at the stage of bacteroid formation is not required for correct symbiosome development.

scholarly journals Rapid Colorimetric Quantification of Lipo-chitooligosaccharides from Mesorhizobium loti and Sinorhizobium meliloti

2002 ◽  
Vol 15 (9) ◽  
pp. 859-865
Author(s):  
Joachim Goedhart ◽  
Jean-Jacques Bono ◽  
Theodorus W. J. Gadella
Keyword(s):  
Methylene Blue ◽  
Organic Phase ◽  
Sinorhizobium Meliloti ◽  
Sodium Dodecyl ◽  
Ion Pair ◽  
Nod Factors ◽  
Two Phase ◽  
Nod Factor ◽  
Mesorhizobium Loti ◽  
Hydrolysis Of

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.

scholarly journals Mutation in GDP-Fucose Synthesis Genes of Sinorhizobium fredii Alters Nod Factors and Significantly Decreases Competitiveness to Nodulate Soybeans

1999 ◽  
Vol 12 (3) ◽  
pp. 207-217 ◽  
Author(s):  
Youssef Lamrabet ◽  
Ramón A. Bellogín ◽  
Teresa Cubo ◽  
Rosario Espuny ◽  
Antonio Gil ◽  
...  
Keyword(s):  
Fatty Acyl ◽  
Side Chain ◽  
Broad Host Range ◽  
Nod Factors ◽  
Nucleotide Sugar ◽  
Sinorhizobium Fredii ◽  
Hindiii Fragment ◽  
Transposon Insertion ◽  
Nodulation Rate ◽  
Soybean Nodulation

We mutagenized Sinorhizobium fredii HH103-1 with Tn5- B20 and screened about 2,000 colonies for increased β-galactosidase activity in the presence of the flavonoid naringenin. One mutant, designated SVQ287, produces lipochitooligosaccharide Nod factors (LCOs) that differ from those of the parental strain. The nonreducing N-acetylglucosamine residues of all of the LCOs of mutant SVQ287 lack fucose and 2-O-methylfucose substituents. In addition, SVQ287 synthesizes an LCO with an unusually long, C20:1 fatty acyl side chain. The transposon insertion of mutant SVQ287 lies within a 1.1-kb HindIII fragment. This and an adjacent 2.4-kb HindIII fragment were sequenced. The sequence contains the 3′ end of noeK, nodZ, and noeL (the gene interrupted by Tn5-B20), and the 5′ end of nolK, all in the same orientation. Although each of these genes has a similarly oriented counterpart on the symbiosis plasmid of the broad-host-range Rhizobium sp. strain NGR234, there are significant differences in the noeK/nodZ intergenic region. Based on amino acid sequence homology, noeL encodes GDP-D-mannose dehydratase, an enzyme involved in the synthesis of GDP-Lfucose, and nolK encodes a NAD-dependent nucleotide sugar epimerase/dehydrogenase. We show that expression of the noeL gene is under the control of NodD1 in S. fredii and is most probably mediated by the nod box that precedes nodZ. Transposon insertion into noeL has two impacts on symbiosis with Williams soybean: nodulation rate is reduced slightly and competitiveness for nodulation is decreased significantly. Mutant SVQ287 retains its ability to form nitrogen-fixing nodules on other legumes, but final nodule number is attenuated on Cajanus cajan.

scholarly journals ALotus japonicuscytoplasmic kinase connects Nod factor perception by the NFR5 LysM receptor to nodulation

2019 ◽  
Vol 116 (28) ◽  
pp. 14339-14348 ◽  
Author(s):  
Jaslyn E. M. M. Wong ◽  
Marcin Nadzieja ◽  
Lene H. Madsen ◽  
Christoph A. Bücherl ◽  
Svend Dam ◽  
...  
Keyword(s):  
Root Nodules ◽  
Lotus Japonicus ◽  
Root Hairs ◽  
Cellular Level ◽  
Dependent Manner ◽  
Nod Factor ◽  
Associated Proteins ◽  
Signaling Process ◽  
Insertion Mutants

The establishment of nitrogen-fixing root nodules in legume–rhizobia symbiosis requires an intricate communication between the host plant and its symbiont. We are, however, limited in our understanding of the symbiosis signaling process. In particular, how membrane-localized receptors of legumes activate signal transduction following perception of rhizobial signaling molecules has mostly remained elusive. To address this, we performed a coimmunoprecipitation-based proteomics screen to identify proteins associated with Nod factor receptor 5 (NFR5) inLotus japonicus.Out of 51 NFR5-associated proteins, we focused on a receptor-like cytoplasmic kinase (RLCK), which we named NFR5-interacting cytoplasmic kinase 4 (NiCK4). NiCK4 associates with heterologously expressed NFR5 inNicotiana benthamiana, and directly binds and phosphorylates the cytoplasmic domains of NFR5 and NFR1 in vitro. At the cellular level,Nick4is coexpressed withNfr5in root hairs and nodule cells, and the NiCK4 protein relocates to the nucleus in an NFR5/NFR1-dependent manner upon Nod factor treatment. Phenotyping of retrotransposon insertion mutants revealed that NiCK4 promotes nodule organogenesis. Together, these results suggest that the identified RLCK, NiCK4, acts as a component of the Nod factor signaling pathway downstream of NFR5.

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