scholarly journals A Dihydroflavonol-4-Reductase-Like Protein Interacts with NFR5 and Regulates Rhizobial Infection in Lotus japonicus

2019 ◽  
Vol 32 (4) ◽  
pp. 401-412 ◽  
Author(s):  
Liujian Duan ◽  
Junqing Pei ◽  
Yaping Ren ◽  
Hao Li ◽  
Xiangzhen Zhou ◽  
...  
Keyword(s):  
Lotus Japonicus ◽  
Root Hairs ◽  
Root Tips ◽  
Symbiotic Interaction ◽  
Nod Factor ◽  
Symbiotic Interactions ◽  
Infection Threads ◽  
Almost All ◽  
Two Hybrid ◽  
Wild Type Control

In almost all symbiotic interactions between rhizobia and leguminous plants, host flavonoid–induced synthesis of Nod factors in rhizobia is required to initiate symbiotic response in plants. In this study, we found that Lotus japonicus Nod factor receptor 5 (LjNFR5) might directly regulate flavonoid biosynthesis during symbiotic interaction with rhizobia. A yeast two-hybrid analysis revealed that a dihydroflavonol-4-reductase-like protein (LjDFL1) interacts with LjNFR5. The interaction between MtDFL1 and MtNFP, two Medicago truncatula proteins with homology to LjDFL1 and LjNFR5, respectively, was also shown, suggesting that interaction between these two proteins might be conserved in different legumes. LjDFL1 was highly expressed in root hairs and epidermal cells of root tips. Lotus ljdfl1 mutants and Medicago mtdfl1 mutants produced significantly fewer infection threads (ITs) than the wild-type control plants following rhizobial treatment. Furthermore, the roots of stable transgenic L. japonicus plants overexpressing LjDFL1 formed more ITs than control roots after exposure to rhizobia. These data indicated that LjDFL1 is a positive regulator of symbiotic signaling. However, the expression of LjDFL1 was suppressed by rhizobial treatment, suggesting that a negative feedback loop might be involved in regulation of the symbiotic response in L. japonicus.

scholarly journals Analysis of Nod-Factor-Induced Calcium Signaling in Root Hairs of Symbiotically Defective Mutants of Lotus japonicus

2006 ◽  
Vol 19 (8) ◽  
pp. 914-923 ◽  
Author(s):  
Hiroki Miwa ◽  
Jongho Sun ◽  
Giles E. D. Oldroyd ◽  
J. Allan Downie
Keyword(s):  
Calcium Influx ◽  
Lotus Japonicus ◽  
Root Hairs ◽  
Calcium Flux ◽  
Symbiotic Interaction ◽  
Nod Factor ◽  
Root Hair Deformation ◽  
Complementation Groups ◽  
Calcium Spiking ◽  
Timing Of Initiation

Nodulation (Nod)-factor signaling molecules are essential for rhizobia to initiate the nitrogen-fixing symbiotic interaction with legumes. Using a dual dye ratiometric calcium imaging technique, we have shown that 10 nM Nod factor added to roots of Lotus japonicus seedlings induces an intra-cellular calcium increase (calcium flux) that precedes oscillations in intracellular calcium (calcium spiking). The calcium flux was not observed with 1 or 0.1 nM Nod factor, which did induce calcium spiking. The calcium flux was variable in timing of initiation and duration and was observed in approximately half of the root hairs examined. Representatives from 11 complementation groups of symbiotically defective mutants were analyzed for the calcium flux. Mutants from four groups (sym6, ccamk, sym35, and nin) which retained calcium spiking all showed a normal calcium flux. Two classes of mutants (nfr1 and nfr5) lacked both calcium influx and calcium spiking, whereas five classes of mutants (symRK, castor, pollux, nup133, and sym24) defective for calcium spiking retained a calcium flux. There was no correlation between calcium spiking and induction of root hair deformation by Nod factor. We propose that increased bacterial numbers within infection foci in root hairs leads to accumulation of Nod factor to sufficient levels to activate the calcium flux, and this may drive infection thread growth.

scholarly journals Identification of Symbiotically Defective Mutants of Lotus japonicus Affected in Infection Thread Growth

2006 ◽  
Vol 19 (12) ◽  
pp. 1444-1450 ◽  
Author(s):  
Fabien Lombardo ◽  
Anne B. Heckmann ◽  
Hiroki Miwa ◽  
Jillian A. Perry ◽  
Koji Yano ◽  
...  
Keyword(s):  
Root Hair ◽  
Plant Cell Wall ◽  
Plant Root ◽  
Lotus Japonicus ◽  
Cortical Cell ◽  
Host Cells ◽  
Infection Thread ◽  
Mycorrhizal Symbiosis ◽  
Symbiotic Interaction ◽  
Infection Threads

During the symbiotic interaction between legumes and rhizobia, the host cell plasma membrane and associated plant cell wall invaginate to form a tunnel-like infection thread, a structure in which bacteria divide to reach the plant root cortex. We isolated four Lotus japonicus mutants that make infection pockets in root hairs but form very few infection threads after inoculation with Mesorhizobium loti. The few infection threads that did initiate in the mutants usually did not progress further than the root hair cell. These infection-thread deficient (itd) mutants were unaffected for early symbiotic responses such as calcium spiking, root hair deformation, and curling, as well as for the induction of cortical cell division and the arbuscular mycorrhizal symbiosis. Complementation tests and genetic mapping indicate that itd2 is allelic to Ljsym7, whereas the itd1, itd3, and itd4 mutations identified novel loci. Bacterial release into host cells did occur occasionally in the itd1, itd2, and itd3 mutants suggesting that some infections may succeed after a long period and that infection of nodule cells could occur normally if the few abnormal infection threads that were formed reached the appropriate nodule cells.

scholarly journals H2O2 Is Required for Optimal Establishment of the Medicago sativa/Sinorhizobium meliloti Symbiosis

2007 ◽  
Vol 189 (23) ◽  
pp. 8741-8745 ◽  
Author(s):  
Alexandre Jamet ◽  
Karine Mandon ◽  
Alain Puppo ◽  
Didier Hérouart
Keyword(s):  
Medicago Sativa ◽  
Plant Cell ◽  
Sinorhizobium Meliloti ◽  
Root Hairs ◽  
Symbiotic Interaction ◽  
Infection Threads ◽  
Cell Layers

ABSTRACT The symbiotic interaction between Medicago sativa and Sinorhizobium meliloti RmkatB ++ overexpressing the housekeeping catalase katB is delayed, and this delay is combined with an enlargement of infection threads. This result provides evidence that H2O2 is required for optimal progression of infection threads through the root hairs and plant cell layers.

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 Lotus japonicus Gene Ljsbp Is Highly Conserved Among Plants and Animals and Encodes a Homologue to the Mammalian Selenium-Binding Proteins

2002 ◽  
Vol 15 (4) ◽  
pp. 313-322 ◽  
Author(s):  
Emmanouil Flemetakis ◽  
Adamantia Agalou ◽  
Nektarios Kavroulakis ◽  
Maria Dimou ◽  
Anna Martsikovskaya ◽  
...  
Keyword(s):  
Polyclonal Antibodies ◽  
Lotus Japonicus ◽  
Root Hairs ◽  
Physiological Role ◽  
Cdna Clones ◽  
Vascular Bundles ◽  
Root Tips ◽  
Root Epidermis ◽  
Infected Cells ◽  
Low Levels

We have isolated and characterized a Lotus japonicus gene (Ljsbp) encoding a putative polypeptide with striking homology to the mammalian 56-kDa selenium-binding protein (SBP). cDNA clones homologous to LjSBP were also isolated from soybean, Medicago sativa, and Arabidopsis thaliana. Comparative expression studies in L. japonicus and A. thaliana showed that sbp transcripts are present in various tissues and at different levels. Especially in L. japonicus nodules and seedpods and A. thaliana siliques, sbp expression appears to be developmentally up-regulated. sbp Gene transcripts were localized by in situ hybridization in the infected cells and vascular bundles of young nodules, while in mature nodules, low levels of expression were only detected in the parenchymatous cells. Expression of sbp transcripts in young seedpods and siliques was clearly visible in vascular tissues and embryos, while in embryos, low levels of expression were detected in the root epidermis and the vascular bundles. Polyclonal antibodies raised against a truncated LjSBP recombinant protein recognized a poly-peptide of about 60 kDa in nodule extracts. Immunohistochemical experiments showed that accumulation of LjSBP occurred in root hairs, in the root epidermis above the nodule primordium, in the phloem of the vasculature, and abundantly in the infected cells of young nodules. Irrespective of the presence of rhizobia, expression of SBP was also observed in root tips, where it was confined in the root epidermis and protophloem cells. We hypothesize that LjSBP may have more than one physiological role and can be implicated in controlling the oxidation/reduction status of target proteins, in vesicular Golgi transport, or both.

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 The Ethylene Responsive Factor Required for Nodulation 1 (ERN1) Transcription Factor Is Required for Infection-Thread Formation in Lotus japonicus

2017 ◽  
Vol 30 (3) ◽  
pp. 194-204 ◽  
Author(s):  
Yasuyuki Kawaharada ◽  
Euan K. James ◽  
Simon Kelly ◽  
Niels Sandal ◽  
Jens Stougaard
Keyword(s):  
Transcription Factor ◽  
Root Nodule ◽  
Lotus Japonicus ◽  
Epidermal Cells ◽  
Infection Thread ◽  
Nod Factor ◽  
Infection Threads ◽  
Thread Formation ◽  
Ethylene Responsive Factor ◽  
Infection Thread Formation

Several hundred genes are transcriptionally regulated during infection-thread formation and development of nitrogen-fixing root nodules. We have characterized a set of Lotus japonicus mutants impaired in root-nodule formation and found that the causative gene, Ern1, encodes a protein with a characteristic APETALA2/Ethylene Responsive Factor (AP2/ERF) transcription-factor domain. Phenotypic characterization of four ern1 alleles shows that infection pockets are formed but root-hair infection threads are absent. Formation of root-nodule primordia is delayed and no normal transcellular infection threads are found in the infected nodules. Corroborating the role of ERN1 (ERF Required for Nodulation1) in nodule organogenesis, spontaneous nodulation induced by an autoactive CCaMK and cytokinin–induced nodule primordia were not observed in ern1 mutants. Expression of Ern1 is induced in the susceptible zone by Nod factor treatment or rhizobial inoculation. At the cellular level, the pErn1:GUS reporter is highly expressed in root epidermal cells of the susceptible zone and in the cortical cells that form nodule primordia. The genetic regulation of this cellular expression pattern was further investigated in symbiotic mutants. Nod factor induction of Ern1 in epidermal cells was found to depend on Nfr1, Cyclops, and Nsp2 but was independent of Nin and Nf-ya1. These results suggest that ERN1 functions as a transcriptional regulator involved in the formation of infection threads and development of nodule primordia and may coordinate these two processes.

scholarly journals The nodD1 gene of Sinorhizobium fredii HH103 Restores Nodulation Capacity on Bean in a Rhizobium tropici CIAT 899 nodD1/nodD2 Mutant, but the Secondary Symbiotic Regulators nolR, nodD2 or syrM Prevent HH103 to Nodulate with This Legume

2022 ◽  
Vol 10 (1) ◽  
pp. 139
Author(s):  
Francisco Fuentes-Romero ◽  
Pilar Navarro-Gómez ◽  
Paula Ayala-García ◽  
Isamar Moyano-Bravo ◽  
Francisco-Javier López-Baena ◽  
...  
Keyword(s):  
Nitrogenase Activity ◽  
Lotus Japonicus ◽  
Rhizobium Tropici ◽  
Sinorhizobium Fredii ◽  
Symbiotic Interaction ◽  
Model Legume ◽  
Nod Factor ◽  
Factor Production ◽  
Nodulation Capacity ◽  
Type 3

Rhizobial NodD proteins and appropriate flavonoids induce rhizobial nodulation gene expression. In this study, we show that the nodD1 gene of Sinorhizobium fredii HH103, but not the nodD2 gene, can restore the nodulation capacity of a double nodD1/nodD2 mutant of Rhizobium tropici CIAT 899 in bean plants (Phaseolus vulgaris). S. fredii HH103 only induces pseudonodules in beans. We have also studied whether the mutation of different symbiotic regulatory genes may affect the symbiotic interaction of HH103 with beans: ttsI (the positive regulator of the symbiotic type 3 protein secretion system), and nodD2, nolR and syrM (all of them controlling the level of Nod factor production). Inactivation of either nodD2, nolR or syrM, but not that of ttsI, affected positively the symbiotic behavior of HH103 with beans, leading to the formation of colonized nodules. Acetylene reduction assays showed certain levels of nitrogenase activity that were higher in the case of the nodD2 and nolR mutants. Similar results have been previously obtained by our group with the model legume Lotus japonicus. Hence, the results obtained in the present work confirm that repression of Nod factor production, provided by either NodD2, NolR or SyrM, prevents HH103 to effectively nodulate several putative host plants.

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.

scholarly journals The Lotus japonicus LjSym4 Gene Is Required for the Successful Symbiotic Infection of Root Epidermal Cells

2000 ◽  
Vol 13 (10) ◽  
pp. 1109-1120 ◽  
Author(s):  
Paola Bonfante ◽  
Andrea Genre ◽  
Antonella Faccio ◽  
Isabella Martini ◽  
Leif Schauser ◽  
...  
Keyword(s):  
Root Hair ◽  
Glomus Intraradices ◽  
Lotus Japonicus ◽  
Am Fungi ◽  
Epidermal Cells ◽  
Parental Line ◽  
Entry Site ◽  
Symbiotic Interaction ◽  
Successful Infection ◽  
Infection Threads

The role of the Lotus japonicus LjSym4 gene during the symbiotic interaction with Mesorhizobium loti and arbuscular mycorrhizal (AM) fungi was analyzed with two mutant alleles conferring phenotypes of different strength. Ljsym4-1 and Ljsym4-2 mutants do not form nodules with M. loti.Normal root hair curling and infection threads are not observed, while a nodC-dependent deformation of root hair tips indicates that nodulation factors are still perceived by Ljsym4 mutants. Fungal infection attempts on the mutants generally abort within the epidermis, but Ljsym4-1 mutants allow rare, successful, infection events, leading to delayed arbuscule formation. On roots of mutants homozygous for the Ljsym4-2 allele, arbuscule formation was never observed upon inoculation with either of the two AM fungi, Glomus intraradices or Gigaspora margarita. The strategy of epidermal penetration by G. margarita was identical for Ljsym4-2 mutants and the parental line, with appressoria, hyphae growing between two epidermal cells, penetration of epidermal cells through their anticlinal wall. These observations define a novel, genetically controlled step in AM colonization. Although rhizobia penetrate the tip of root hairs and AM fungi access an entry site near the base of epidermal cells, the LjSym4 gene is necessary for the appropriate response of this cell type to both microsymbionts. We propose that LjSym4 is required for the initiation or coordinated expression of the host plant cell's accommodation program, allowing the passage of both microsymbionts through the epidermis layer.

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