scholarly journals Identification of a dominant gene in Medicago truncatula that restricts nodulation by Sinorhizobium meliloti strain Rm41

2014 ◽  
Vol 14 (1) ◽  
pp. 167 ◽  
Author(s):  
Jinge Liu ◽  
Shengming Yang ◽  
Qiaolin Zheng ◽  
Hongyan Zhu
Keyword(s):  
Medicago Truncatula ◽  
Sinorhizobium Meliloti ◽  
Dominant Gene ◽  
Meliloti Strain

scholarly journals Nodule-Specific Cysteine-Rich Peptides Negatively Regulate Nitrogen-Fixing Symbiosis in a Strain-Specific Manner in Medicago truncatula

2018 ◽  
Vol 31 (2) ◽  
pp. 240-248 ◽  
Author(s):  
Qi Wang ◽  
Jinge Liu ◽  
Hua Li ◽  
Shengming Yang ◽  
Peter Körmöczi ◽  
...  
Keyword(s):  
Medicago Truncatula ◽  
Sinorhizobium Meliloti ◽  
Molecular Mechanisms ◽  
Nodule Development ◽  
Nitrogen Fixing ◽  
Plant Genotype ◽  
Specific Manner ◽  
Meliloti Strain ◽  
High Level ◽  
Symbiotic Partner

Medicago truncatula shows a high level of specificity when interacting with its symbiotic partner Sinorhizobium meliloti. This specificity is mainly manifested at the nitrogen-fixing stage of nodule development, such that a particular bacterial strain forms nitrogen-fixing nodules (Nod+/Fix+) on one plant genotype but ineffective nodules (Nod+/Fix−) on another. Recent studies have just begun to reveal the underlying molecular mechanisms that control this specificity. The S. meliloti strain A145 induces the formation of Fix+ nodules on the accession DZA315.16 but Fix− nodules on Jemalong A17. A previous study reported that the formation of Fix− nodules on Jemalong A17 by S. meliloti A145 was conditioned by a single recessive allele named Mtsym6. Here we demonstrate that the specificity associated with S. meliloti A145 is controlled by multiple genes in M. truncatula, including NFS1 and NFS2 that encode nodule-specific cysteine-rich (NCR) peptides. The two NCR peptides acted dominantly to block rather than promote nitrogen fixation by S. meliloti A145. These two NCR peptides are the same ones that negatively regulate nitrogen-fixing symbiosis associated with S. meliloti Rm41.

scholarly journals Expression of Medicago truncatula Genes Responsive to Nitric Oxide in Pathogenic and Symbiotic Conditions

2008 ◽  
Vol 21 (6) ◽  
pp. 781-790 ◽  
Author(s):  
Alberto Ferrarini ◽  
Matteo De Stefano ◽  
Emmanuel Baudouin ◽  
Chiara Pucciariello ◽  
Annalisa Polverari ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Medicago Truncatula ◽  
Regulatory Networks ◽  
Sinorhizobium Meliloti ◽  
Biotic Interactions ◽  
Hypersensitive Reaction ◽  
Nodule Formation ◽  
Polymorphism Analysis ◽  
Symbiotic Interaction ◽  
Physiological Relevance

Nitric oxide (NO) is involved in diverse physiological processes in plants, including growth, development, response to pathogens, and interactions with beneficial microorganisms. In this work, a dedicated microarray representing the widest database available of NO-related transcripts in plants has been produced with 999 genes identified by a cDNA amplified fragment length polymorphism analysis as modulated in Medicago truncatula roots treated with two NO donors. The microarray then was used to monitor the expression of NO-responsive genes in M. truncatula during the incompatible interaction with the foliar pathogen Colletotrichum trifolii race 1 and during the symbiotic interaction with Sinorhizobium meliloti 1021. A wide modulation of NO-related genes has been detected during the hypersensitive reaction or during nodule formation and is discussed with special emphasis on the physiological relevance of these genes in the context of the two biotic interactions. This work clearly shows that NO-responsive genes behave differently depending on the plant organ and on the type of interaction, strengthening the need to consider regulatory networks, including different signaling molecules.

scholarly journals Structure and antimicrobial activity of NCR169, a nodule-specific cysteine-rich peptide of Medicago truncatula

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Noriyoshi Isozumi ◽  
Yuya Masubuchi ◽  
Tomohiro Imamura ◽  
Masashi Mori ◽  
Hironori Koga ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Medicago Truncatula ◽  
Mechanism Of Action ◽  
Disulfide Bonds ◽  
Sinorhizobium Meliloti ◽  
Bound State ◽  
Disulfide Linkage ◽  
Model Legume ◽  
Nmr Structures ◽  
And Function

AbstractA model legume, Medicago truncatula, has over 600 nodule-specific cysteine-rich (NCR) peptides required for symbiosis with rhizobia. Among them, NCR169, an essential factor for establishing symbiosis, has four cysteine residues that are indispensable for its function. However, knowledge of NCR169 structure and mechanism of action is still lacking. In this study, we solved two NMR structures of NCR169 caused by different disulfide linkage patterns. We show that both structures have a consensus C-terminal β-sheet attached to an extended N-terminal region with dissimilar features; one moves widely, whereas the other is relatively stapled. We further revealed that the disulfide bonds of NCR169 contribute to its structural stability and solubility. Regarding the function, one of the NCR169 oxidized forms could bind to negatively charged bacterial phospholipids. Furthermore, the positively charged lysine-rich region of NCR169 may be responsible for its antimicrobial activity against Escherichia coli and Sinorhizobium meliloti. This active region was disordered even in the phospholipid bound state, suggesting that the disordered conformation of this region is key to its function. Morphological observations suggested the mechanism of action of NCR169 on bacteria. The present study on NCR169 provides new insights into the structure and function of NCR peptides.

scholarly journals Analysis of the chromosome sequence of the legume symbiont Sinorhizobium meliloti strain 1021

2001 ◽  
Vol 98 (17) ◽  
pp. 9877-9882 ◽  
Author(s):  
D. Capela ◽  
F. Barloy-Hubler ◽  
J. Gouzy ◽  
G. Bothe ◽  
F. Ampe ◽  
...  
Keyword(s):  
Sinorhizobium Meliloti ◽  
Chromosome Sequence ◽  
Meliloti Strain

scholarly journals Inoculation with Efficient Nitrogen Fixing and Indoleacetic Acid Producing Bacterial Microsymbiont Enhance Tolerance of the Model LegumeMedicago truncatulato Iron Deficiency

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Nadia Kallala ◽  
Wissal M’sehli ◽  
Karima Jelali ◽  
Zribi Kais ◽  
Haythem Mhadhbi
Keyword(s):  
Oxidative Stress ◽  
Iron Deficiency ◽  
Medicago Truncatula ◽  
Sinorhizobium Meliloti ◽  
Plant Biomass ◽  
High Growth ◽  
Fe Deficiency ◽  
Nitrogen Fixing ◽  
Bacterial Strains ◽  
Negative Effect

The aim of this study was to assess the effect of symbiotic bacteria inoculation on the response ofMedicago truncatulagenotypes to iron deficiency. The present work was conducted on threeMedicago truncatulagenotypes: A17, TN8.20, and TN1.11. Three treatments were performed: control (C), direct Fe deficiency (DD), and induced Fe deficiency by bicarbonate (ID). Plants were nitrogen-fertilized (T) or inoculated with two bacterial strains:Sinorhizobium melilotiTII7 andSinorhizobium medicaeSII4. Biometric, physiological, and biochemical parameters were analyzed. Iron deficiency had a significant lowering effect on plant biomass and chlorophyll content in allMedicago truncatulagenotypes. TN1.11 showed the highest lipid peroxidation and leakage of electrolyte under iron deficiency conditions, which suggest that TN1.11 was more affected than A17 and TN8.20 by Fe starvation. Iron deficiency affected symbiotic performance indices of allMedicago truncatulagenotypes inoculated with bothSinorhizobiumstrains, mainly nodules number and biomass as well as nitrogen-fixing capacity. Nevertheless, inoculation withSinorhizobiumstrains mitigates the negative effect of Fe deficiency on plant growth and oxidative stress compared to nitrogen-fertilized plants. The highest auxin producing strain, TII7, preserves relatively high growth and root biomass and length when inoculated to TN8.20 and A17. On the other hand, both TII7 and SII4 strains improve the performance of sensitive genotype TN1.11 through reduction of the negative effect of iron deficiency on chlorophyll and plant Fe content. The bacterial inoculation improved Fe-deficient plant response to oxidative stress via the induction of the activities of antioxidant enzymes.

scholarly journals Quorum quenching activity of the PGPR Bacillus subtilis UD1022 alters nodulation efficiency of Sinorhizobium meliloti on Medicago truncatula

2020 ◽  
Author(s):  
Amanda Rosier ◽  
Pascale B. Beauregard ◽  
Harsh P. Bais
Keyword(s):  
Bacillus Subtilis ◽  
Plant Growth ◽  
Medicago Truncatula ◽  
Sinorhizobium Meliloti ◽  
Quorum Quenching ◽  
Agricultural System ◽  
Synergistic Activity ◽  
Sustainable Solutions ◽  
Plant Growth Promoting ◽  
Growth Promoting

AbstractPlant growth promoting rhizobacteria (PGPR) have enormous potential for solving some of the myriad challenges facing our global agricultural system. Intense research efforts are rapidly moving the field forward and illuminating the wide diversity of bacteria and their plant beneficial activities. In the development of better crop solutions using these PGPR, producers are including multiple different species of PGPR in their formulations in a ‘consortia’ approach. While the intention is to emulate more natural rhizomicrobiome systems, the aspect of bacterial interactions has not been properly regarded. By using a tri-trophic model of Medicago truncatula A17 Jemalong, its nitrogen (N)-fixing symbiont Sinorhizobium meliloti Rm8530 and the PGPR Bacillus subtilis UD1022, we demonstrate indirect influences between the bacteria affecting their plant growth promoting activities. Co-cultures of UD1022 with Rm8530 significantly reduced Rm8530 biofilm formation and downregulated quorum sensing (QS) genes responsible for symbiotically active biofilm production. This work also identifies the presence and activity of a quorum quenching lactonase in UD1022 and proposes this as the mechanism for non-synergistic activity of this model ‘consortium’. These interspecies interactions may be common in the rhizosphere and are critical to understand as we seek to develop new sustainable solutions in agriculture.

scholarly journals The Medicago truncatula N5 Gene Encoding a Root-Specific Lipid Transfer Protein Is Required for the Symbiotic Interaction with Sinorhizobium meliloti

2009 ◽  
Vol 22 (12) ◽  
pp. 1577-1587 ◽  
Author(s):  
Youry Pii ◽  
Alessandra Astegno ◽  
Elisa Peroni ◽  
Massimo Zaccardelli ◽  
Tiziana Pandolfini ◽  
...  
Keyword(s):  
Medicago Truncatula ◽  
Sinorhizobium Meliloti ◽  
Lipid Transfer Protein ◽  
Symbiotic Association ◽  
Lipid Transfer ◽  
Symbiotic Interaction ◽  
Transgenic Roots ◽  
Transfer Protein ◽  
Small Proteins

The Medicago truncatula N5 gene is induced in roots after Sinorhizobium meliloti infection and it codes for a putative lipid transfer protein (LTP), a family of plant small proteins capable of binding and transferring lipids between membranes in vitro. Various biological roles for plant LTP in vivo have been proposed, including defense against pathogens and modulation of plant development. The aim of this study was to shed light on the role of MtN5 in the symbiotic interaction between M. truncatula and S. meliloti. MtN5 cDNA was cloned and the mature MtN5 protein expressed in Escherichia coli. The lipid binding capacity and antimicrobial activity of the recombinant MtN5 protein were tested in vitro. MtN5 showed the capacity to bind lysophospholipids and to inhibit M. truncatula pathogens and symbiont growth in vitro. Furthermore, MtN5 was upregulated in roots after infection with either the fungal pathogen Fusarium semitectum or the symbiont S. meliloti. Upon S. meliloti infection, MtN5 was induced starting from 1 day after inoculation (dpi). It reached the highest concentration at 3 dpi and it was localized in the mature nodules. MtN5-silenced roots were impaired in nodulation, showing a 50% of reduction in the number of nodules compared with control roots. On the other hand, transgenic roots overexpressing MtN5 developed threefold more nodules with respect to control roots. Here, we demonstrate that MtN5 possesses biochemical features typical of LTP and that it is required for the successful symbiotic association between M. truncatula and S. meliloti.

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