scholarly journals The rhizobial autotransporter determines the symbiotic nitrogen fixation activity of Lotus japonicus in a host-specific manner

2020 ◽  
Vol 117 (3) ◽  
pp. 1806-1815 ◽  
Author(s):  
Yoshikazu Shimoda ◽  
Yuki Nishigaya ◽  
Hiroko Yamaya-Ito ◽  
Noritoshi Inagaki ◽  
Yosuke Umehara ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Host Plant ◽  
Symbiotic Nitrogen Fixation ◽  
Root Nodules ◽  
Lotus Japonicus ◽  
Dependent Manner ◽  
Strain Specificity ◽  
Passenger Domain ◽  
Aspartic Peptidase ◽  
Specific Manner

Leguminous plants establish endosymbiotic associations with rhizobia and form root nodules in which the rhizobia fix atmospheric nitrogen. The host plant and intracellular rhizobia strictly control this symbiotic nitrogen fixation. We recently reported a Lotus japonicus Fix− mutant, apn1 (aspartic peptidase nodule-induced 1), that impairs symbiotic nitrogen fixation. APN1 encodes a nodule-specific aspartic peptidase involved in the Fix− phenotype in a rhizobial strain-specific manner. This host-strain specificity implies that some molecular interactions between host plant APN1 and rhizobial factors are required, although the biological function of APN1 in nodules and the mechanisms governing the interactions are unknown. To clarify how rhizobial factors are involved in strain-specific nitrogen fixation, we explored transposon mutants of Mesorhizobium loti strain TONO, which normally form Fix− nodules on apn1 roots, and identified TONO mutants that formed Fix+ nodules on apn1. The identified causal gene encodes an autotransporter, part of a protein secretion system of Gram-negative bacteria. Expression of the autotransporter gene in M. loti strain MAFF3030399, which normally forms Fix+ nodules on apn1 roots, resulted in Fix− nodules. The autotransporter of TONO functions to secrete a part of its own protein (a passenger domain) into extracellular spaces, and the recombinant APN1 protein cleaved the passenger protein in vitro. The M. loti autotransporter showed the activity to induce the genes involved in nodule senescence in a dose-dependent manner. Therefore, we conclude that the nodule-specific aspartic peptidase, APN1, suppresses negative effects of the rhizobial autotransporter in order to maintain effective symbiotic nitrogen fixation in root nodules.

3-Phosphoglycerate dehydrogenase in Mesorhizobioum loti is essential for maintaining symbiotic nitrogen fixation of Lotus japonicus root nodules

2010 ◽  
Vol 336 (1-2) ◽  
pp. 233-240 ◽  
Author(s):  
Nanthipak Thapanapongworakul ◽  
Mika Nomura ◽  
Tan Van Dao ◽  
Yoshikazu Shimoda ◽  
Shusei Sato ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Symbiotic Nitrogen Fixation ◽  
Root Nodules ◽  
Lotus Japonicus ◽  
Phosphoglycerate Dehydrogenase

scholarly journals The Sulfate Transporter SST1 Is Crucial for Symbiotic Nitrogen Fixation in Lotus japonicus Root Nodules

2005 ◽  
Vol 17 (5) ◽  
pp. 1625-1636 ◽  
Author(s):  
Lene Krusell ◽  
Katja Krause ◽  
Thomas Ott ◽  
Guilhem Desbrosses ◽  
Ute Krämer ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Symbiotic Nitrogen Fixation ◽  
Root Nodules ◽  
Lotus Japonicus ◽  
Sulfate Transporter

scholarly journals Nitrate restricts nodule organogenesis through inhibition of cytokinin biosynthesis in Lotus japonicus

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jieshun Lin ◽  
Yuda Purwana Roswanjaya ◽  
Wouter Kohlen ◽  
Jens Stougaard ◽  
Dugald Reid
Keyword(s):  
Nitrogen Fixation ◽  
Developmental Process ◽  
Root Zone ◽  
Root Nodules ◽  
Lotus Japonicus ◽  
Nodule Development ◽  
Nodule Formation ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Cytokinin Biosynthesis

AbstractLegumes balance nitrogen acquisition from soil nitrate with symbiotic nitrogen fixation. Nitrogen fixation requires establishment of a new organ, which is a cytokinin dependent developmental process in the root. We found cytokinin biosynthesis is a central integrator, balancing nitrate signalling with symbiotic acquired nitrogen. Low nitrate conditions provide a permissive state for induction of cytokinin by symbiotic signalling and thus nodule development. In contrast, high nitrate is inhibitory to cytokinin accumulation and nodule establishment in the root zone susceptible to nodule formation. This reduction of symbiotic cytokinin accumulation was further exacerbated in cytokinin biosynthesis mutants, which display hypersensitivity to nitrate inhibition of nodule development, maturation and nitrogen fixation. Consistent with this, cytokinin application rescues nodulation and nitrogen fixation of biosynthesis mutants in a concentration dependent manner. These inhibitory impacts of nitrate on symbiosis occur in a Nlp1 and Nlp4 dependent manner and contrast with the positive influence of nitrate on cytokinin biosynthesis that occurs in species that do not form symbiotic root nodules. Altogether this shows that legumes, as exemplified by Lotus japonicus, have evolved a different cytokinin response to nitrate compared to non-legumes.

scholarly journals Αναπρογραμματισμός του μεταβολισμού του Lotus japonicus σε μεταγραφικό, βιοχημικό και μεταβολομικό επίπεδο κατά τη συμβιωτική αζωτοδέσμευση

2016 ◽  
Author(s):  
Χρυσάνθη Καλλονιάτη
Keyword(s):  
Nitrogen Fixation ◽  
Metabolite Profiling ◽  
Symbiotic Nitrogen Fixation ◽  
Sulfur Metabolism ◽  
Lotus Japonicus ◽  
Nitrogen Fixing ◽  
Model Legume ◽  
Whole Plant ◽  
Plant Level ◽  
Molecular And Biochemical Mechanisms

Symbiotic nitrogen fixation in legumes takes place in specialized organs called nodules,which become the main source of assimilated nitrogen for the whole plant. Symbiotic nitro‐gen fixation requires exquisite integration of plant and bacterial metabolism and involvesglobal changes in gene expression and metabolite accumulation in both rhizobia and thehost plant. In order to study the metabolic changes mediated by symbiotic nitrogen fixationon a whole‐plant level, metabolite levels were profiled by gas chromatography–mass spec‐trometry in nodules and non‐symbiotic organs of Lotus japonicus plants uninoculated or in‐oculated with M. loti wt,  ΔnifA or  ΔnifH fix‐ strains. Furthermore, transcriptomic andbiochemical approaches were combined to study sulfur metabolism in nodules, its link tosymbiotic nitrogen fixation, and the effect of nodules on whole‐plant sulfur partitioning andmetabolism. It is well established that nitrogen and sulfur (S) metabolism are tightly en‐twined and sulfur is required for symbiotic nitrogen fixation, however, little is known aboutthe molecular and biochemical mechanisms governing sulfur uptake and assimilation duringsymbiotic nitrogen fixation. Transcript profiling in Lotus japonicus was combined with quan‐tification of S‐metabolite contents and APR activity in nodules and in non‐symbiotic organsof plants uninoculated or inoculated with M. loti wt, ΔnifA or ΔnifH fix‐ strains. Moreover,sulfate uptake and its distribution into different plant organs were analyzed and 35S‐flux intodifferent S‐pools was monitored. Metabolite profiling revealed that symbiotic nitrogen fixa‐tion results in dramatic changes of many aspects of primary and secondary metabolism innodules which leads to global reprogramming of metabolism of the model legume on awhole‐plant level. Moreover, our data revealed that nitrogen fixing nodules represent athiol‐rich organ. Their high APR activity and 35S‐flux into cysteine and its metabolites in com‐bination with the transcriptional up‐regulation of several genes involved in sulfur assimila‐tion highlight the function of nodules as a new site of sulfur assimilation. The higher thiolcontent observed in non‐symbiotic organs of nitrogen fixing plants in comparison touninoculated plants cannot be attributed to local biosynthesis, indicating that nodules couldserve as a novel source of reduced sulfur for the plant, which triggers whole‐plant repro‐gramming of sulfur metabolism. Interestingly, the changes in metabolite profiling and theenhanced thiol biosynthesis in nodules and their impact on the whole‐plant sulfur, carbonand nitrogen economy are dampened in fix‐ plants, which in most respects metabolically re‐sembled uninoculated plants, indicating a strong interaction between nitrogen fixation andsulfur and carbon metabolism.

scholarly journals MIR2111-5 locus and shoot-accumulated mature miR2111 systemically enhance nodulation depending on HAR1 in Lotus japonicus

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Nao Okuma ◽  
Takashi Soyano ◽  
Takuya Suzaki ◽  
Masayoshi Kawaguchi
Keyword(s):  
Root Nodules ◽  
Lotus Japonicus ◽  
Dependent Manner ◽  
Rna Seq ◽  
Signaling System ◽  
Nodule Number ◽  
Knockout Mutants ◽  
Mutualistic Relationship ◽  
Dose Dependent

Abstract Legumes utilize a shoot-mediated signaling system to maintain a mutualistic relationship with nitrogen-fixing bacteria in root nodules. In Lotus japonicus, shoot-to-root transfer of microRNA miR2111 that targets TOO MUCH LOVE, a nodulation suppressor in roots, has been proposed to explain the mechanism underlying nodulation control from shoots. However, the role of shoot-accumulating miR2111s for the systemic regulation of nodulation was not clearly shown. Here, we find L. japonicus has seven miR2111 loci, including those mapped through RNA-seq. MIR2111-5 expression in leaves is the highest among miR2111 loci and repressed after rhizobial infection depending on a shoot-acting HYPERNODULATION ABERRANT ROOT FORMATION1 (HAR1) receptor. MIR2111-5 knockout mutants show significantly decreased nodule numbers and miR2111 levels. Furthermore, grafting experiments using transformants demonstrate scions with altered miR2111 levels influence nodule numbers in rootstocks in a dose-dependent manner. Therefore, miR2111 accumulation in leaves through MIR2111-5 expression is required for HAR1-dependent systemic optimization of nodule number.

scholarly journals CRISPR/Cas9 knockout of leghemoglobin genes in Lotus japonicus uncovers their synergistic roles in symbiotic nitrogen fixation

2019 ◽  
Vol 224 (2) ◽  
pp. 818-832 ◽  
Author(s):  
Longlong Wang ◽  
Maria Carmen Rubio ◽  
Xian Xin ◽  
Baoli Zhang ◽  
Qiuling Fan ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Symbiotic Nitrogen Fixation ◽  
Lotus Japonicus

scholarly journals The SNARE Protein SYP71 Expressed in Vascular Tissues Is Involved in Symbiotic Nitrogen Fixation in Lotus japonicus Nodules

2012 ◽  
Vol 160 (2) ◽  
pp. 897-905 ◽  
Author(s):  
Tsuneo Hakoyama ◽  
Ryo Oi ◽  
Kazuya Hazuma ◽  
Eri Suga ◽  
Yuka Adachi ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Symbiotic Nitrogen Fixation ◽  
Lotus Japonicus ◽  
Snare Protein ◽  
Vascular Tissues

scholarly journals Absence of Symbiotic Leghemoglobins Alters Bacteroid and Plant Cell Differentiation During Development of Lotus japonicus Root Nodules

2009 ◽  
Vol 22 (7) ◽  
pp. 800-808 ◽  
Author(s):  
Thomas Ott ◽  
John Sullivan ◽  
Euan K. James ◽  
Emmanouil Flemetakis ◽  
Catrin Günther ◽  
...  
Keyword(s):  
Gene Expression ◽  
Nitrogen Fixation ◽  
Cell Differentiation ◽  
Root Nodules ◽  
Lotus Japonicus ◽  
Nodule Development ◽  
Primary And Secondary Metabolism ◽  
Bacterial Differentiation ◽  
Plant Genes ◽  
Bacterial Genes

During development of legume root nodules, rhizobia and their host plant cells undergo profound differentiation, which is underpinned by massive changes in gene expression in both symbiotic partners. Oxygen concentrations in infected and surrounding uninfected cells drop precipitously during nodule development. To assess what effects this has on plant and bacterial cell differentiation and gene expression, we used a leghemoglobin-RNA-interference (LbRNAi) line of Lotus japonicus, which is devoid of leghemoglobins and has elevated levels of free-oxygen in its nodules. Bacteroids in LbRNAi nodules showed altered ultrastructure indicating changes in bacterial differentiation. Transcript analysis of 189 plant and 192 bacterial genes uncovered many genes in both the plant and bacteria that were differentially regulated during nodulation of LbRNAi plants compared with the wild type (containing Lb and able to fix nitrogen). These included fix and nif genes of the bacteria, which are involved in microaerobic respiration and nitrogen fixation, respectively, and plant genes involved in primary and secondary metabolism. Metabolite analysis revealed decreased levels of many amino acids in nodules of LbRNAi plants, consistent with the defect in symbiotic nitrogen fixation of this line.

scholarly journals Loss of the nodule-specific cysteine rich peptide, NCR169, abolishes symbiotic nitrogen fixation in the Medicago truncatula dnf7 mutant

2015 ◽  
Vol 112 (49) ◽  
pp. 15232-15237 ◽  
Author(s):  
Beatrix Horváth ◽  
Ágota Domonkos ◽  
Attila Kereszt ◽  
Attila Szűcs ◽  
Edit Ábrahám ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Medicago Truncatula ◽  
Symbiotic Nitrogen Fixation ◽  
Root Nodules ◽  
Nitrogen Fixing ◽  
In Planta ◽  
Functional Roles ◽  
Absolute Requirement ◽  
Cell Layers

Host compatible rhizobia induce the formation of legume root nodules, symbiotic organs within which intracellular bacteria are present in plant-derived membrane compartments termed symbiosomes. In Medicago truncatula nodules, the Sinorhizobium microsymbionts undergo an irreversible differentiation process leading to the development of elongated polyploid noncultivable nitrogen fixing bacteroids that convert atmospheric dinitrogen into ammonia. This terminal differentiation is directed by the host plant and involves hundreds of nodule specific cysteine-rich peptides (NCRs). Except for certain in vitro activities of cationic peptides, the functional roles of individual NCR peptides in planta are not known. In this study, we demonstrate that the inability of M. truncatula dnf7 mutants to fix nitrogen is due to inactivation of a single NCR peptide, NCR169. In the absence of NCR169, bacterial differentiation was impaired and was associated with early senescence of the symbiotic cells. Introduction of the NCR169 gene into the dnf7-2/NCR169 deletion mutant restored symbiotic nitrogen fixation. Replacement of any of the cysteine residues in the NCR169 peptide with serine rendered it incapable of complementation, demonstrating an absolute requirement for all cysteines in planta. NCR169 was induced in the cell layers in which bacteroid elongation was most pronounced, and high expression persisted throughout the nitrogen-fixing nodule zone. Our results provide evidence for an essential role of NCR169 in the differentiation and persistence of nitrogen fixing bacteroids in M. truncatula.

scholarly journals Induction and Spatial Organization of Polyamine Biosynthesis During Nodule Development in Lotus japonicus

2004 ◽  
Vol 17 (12) ◽  
pp. 1283-1293 ◽  
Author(s):  
Emmanouil Flemetakis ◽  
Rodica C. Efrose ◽  
Guilhem Desbrosses ◽  
Maria Dimou ◽  
Costas Delis ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Symbiotic Nitrogen Fixation ◽  
Expression Patterns ◽  
Lotus Japonicus ◽  
Cyclin D3 ◽  
Nodule Development ◽  
Cdna Clones ◽  
Long Distance ◽  
Polyamine Biosynthesis ◽  
Transcript Levels

Putrescine and other polyamines are produced by two alternative pathways in plants. One pathway starts with the enzyme arginine decarboxylase (ADC; EC 4.1.1.19), the other with ornithine decarboxylase (ODC; EC 4.1.1.17). Metabolite profiling of nitrogen-fixing Lotus japonicus nodules, using gas chromatography coupled to mass spectrometry, revealed a two- to sixfold increase in putrescine levels in mature nodules compared with other organs. Genes involved in polyamine biosynthesis in L. japonicus nodules were identified by isolating cDNA clones encoding ADC (LjADC1) and ODC (LjODC) from a nodule library. Searches of the public expressed sequence tag databases revealed the presence of a second gene encoding ADC (LjADC2). Real-time reverse-transcription-polymerase chain reaction analysis showed that LjADC1 and LjADC2 were expressed throughout the plant, while LjODC transcripts were detected only in nodules and roots. Induction of LjODC and LjADC gene expression during nodule development preceded symbiotic nitrogen fixation. Transcripts accumulation was maximal at 10 days postinfection, when a 6.5-fold increase in the transcript levels of LjODC was observed in comparison with the uninfected roots, while a twofold increase in the transcript levels of LjADC1 and LjADC2 was detected. At later stages of nodule development, transcripts for ADC drastically declined, while in the case of ODC, transcript accumulation was higher than that in roots until after 21 days postinfection. The expression profile of genes involved in putrescine biosynthesis correlated well with the expression patterns of genes involved in cell division and expansion, including a L. japonicus Cyclin D3 and an α-expansin gene. Spatial localization of LjODC and LjADC1 gene transcripts in developing nodules revealed that both transcripts were expressed in nodule inner cortical cells and in the central tissue. High levels of LjADC1 transcripts were also observed in both nodule and connecting root vascular tissue, suggesting that putrescine and other polyamines may be subject to long-distance transport. Our results indicate that polyamines are primarily involved in physiological and cellular processes involved in nodule development, rather than in processes that support directly symbiotic nitrogen fixation and assimilation.

Sign in / Sign up

Export Citation Format

Share Document