scholarly journals Gene Expression in Nitrogen-Fixing Symbiotic Nodule Cells in Medicago truncatula and Other Nodulating Plants

2019 ◽  
Vol 32 (1) ◽  
pp. 42-68 ◽  
Author(s):  
Peter Mergaert ◽  
Attila Kereszt ◽  
Eva Kondorosi
Keyword(s):  
Gene Expression ◽  
Medicago Truncatula ◽  
Nitrogen Fixing ◽  
Symbiotic Nodule

scholarly journals Transcriptomic Analysis of Sinorhizobium meliloti and Medicago truncatula Symbiosis Using Nitrogen Fixation–Deficient Nodules

2015 ◽  
Vol 28 (8) ◽  
pp. 856-868 ◽  
Author(s):  
Claus Lang ◽  
Sharon R. Long
Keyword(s):  
Gene Expression ◽  
Nitrogen Fixation ◽  
Bacterial Infection ◽  
Medicago Truncatula ◽  
Sinorhizobium Meliloti ◽  
Cell Envelope ◽  
Root Nodules ◽  
Bacterial Cells ◽  
Nitrogen Fixing ◽  
Bacterial Genes

The bacterium Sinorhizobium meliloti interacts symbiotically with legume plant hosts such as Medicago truncatula to form nitrogen-fixing root nodules. During symbiosis, plant and bacterial cells differentiate in a coordinated manner, resulting in specialized plant cells that contain nitrogen-fixing bacteroids. Both plant and bacterial genes are required at each developmental stage of symbiosis. We analyzed gene expression in nodules formed by wild-type bacteria on six plant mutants with defects in nitrogen fixation. We observed differential expression of 482 S. meliloti genes with functions in cell envelope homeostasis, cell division, stress response, energy metabolism, and nitrogen fixation. We simultaneously analyzed gene expression in M. truncatula and observed differential regulation of host processes that may trigger bacteroid differentiation and control bacterial infection. Our analyses of developmentally arrested plant mutants indicate that plants use distinct means to control bacterial infection during early and late symbiotic stages.

scholarly journals Ploidy-dependent changes in the epigenome of symbiotic cells correlate with specific patterns of gene expression

2017 ◽  
Vol 114 (17) ◽  
pp. 4543-4548 ◽  
Author(s):  
Marianna Nagymihály ◽  
Alaguraj Veluchamy ◽  
Zoltán Györgypál ◽  
Federico Ariel ◽  
Teddy Jégu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Medicago Truncatula ◽  
The Other ◽  
Small Subset ◽  
Epigenetic Changes ◽  
Ploidy Levels ◽  
Transcriptional Reprogramming ◽  
Other Hand ◽  
Symbiotic Nodule

The formation of symbiotic nodule cells in Medicago truncatula is driven by successive endoreduplication cycles and transcriptional reprogramming in different temporal waves including the activation of more than 600 cysteine-rich NCR genes expressed only in nodules. We show here that the transcriptional waves correlate with growing ploidy levels and have investigated how the epigenome changes during endoreduplication cycles. Differential DNA methylation was found in only a small subset of symbiotic nodule-specific genes, including more than half of the NCR genes, whereas in most genes DNA methylation was unaffected by the ploidy levels and was independent of the genes’ active or repressed state. On the other hand, expression of nodule-specific genes correlated with ploidy-dependent opening of the chromatin as well as, in a subset of tested genes, with reduced H3K27me3 levels combined with enhanced H3K9ac levels. Our results suggest that endoreduplication-dependent epigenetic changes contribute to transcriptional reprogramming in the differentiation of symbiotic cells.

Isolation and characterization of non‐transposon symbiotic nitrogen fixing mutants of Medicago truncatula

2019 ◽  
pp. 1006-1014
Author(s):  
Gyöngyi Zs. Kontra‐Kováts ◽  
Lili Fodor ◽  
Beatrix Horváth ◽  
Ágota Domonkos ◽  
Gergely Iski ◽  
...  
Keyword(s):  
Medicago Truncatula ◽  
Nitrogen Fixing ◽  
Isolation And Characterization

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 LeGOO: An Expertized Knowledge Database for the Model Legume Medicago truncatula

2019 ◽  
Vol 61 (1) ◽  
pp. 203-211 ◽  
Author(s):  
S�bastien Carr�re ◽  
Marion Verdenaud ◽  
Clare Gough ◽  
J�r�me Gouzy ◽  
Pascal Gamas
Keyword(s):  
Medicago Truncatula ◽  
Reverse Genetics ◽  
Arbuscular Mycorrhizal ◽  
Biological Information ◽  
Model Species ◽  
Model Legume ◽  
Wide Range ◽  
Legume Symbiosis ◽  
Symbiotic Nodule ◽  
Set Up

Abstract Medicago truncatula was proposed, about three decades ago, as a model legume to study the Rhizobium-legume symbiosis. It has now been adopted to study a wide range of biological questions, including various developmental processes (in particular root, symbiotic nodule and seed development), symbiotic (nitrogen-fixing and arbuscular mycorrhizal endosymbioses) and pathogenic interactions, as well as responses to abiotic stress. With a number of tools and resources set up in M. truncatula for omics, genetics and reverse genetics approaches, massive amounts of data have been produced, as well as four genome sequence releases. Many of these data were generated with heterogeneous tools, notably for transcriptomics studies, and are consequently difficult to integrate. This issue is addressed by the LeGOO (for Legume Graph-Oriented Organizer) knowledge base (https://www.legoo.org), which finds the correspondence between the multiple identifiers of the same gene. Furthermore, an important goal of LeGOO is to collect and represent biological information from peer-reviewed publications, whatever the technical approaches used to obtain this information. The information is modeled in a graph-oriented database, which enables flexible representation, with currently over 200,000 relations retrieved from 298 publications. LeGOO also provides the user with mining tools, including links to the Mt5.0 genome browser and associated information (on gene functional annotation, expression, methylome, natural diversity and available insertion mutants), as well as tools to navigate through different model species. LeGOO is, therefore, an innovative database that will be useful to the Medicago and legume community to better exploit the wealth of data produced on this model species.

Metabolic and gene expression hallmarks of seed germination uncovered by sodium butyrate in Medicago truncatula

2018 ◽  
Vol 42 (1) ◽  
pp. 259-269 ◽  
Author(s):  
Andrea Pagano ◽  
Susana de Sousa Araújo ◽  
Anca Macovei ◽  
Daniele Dondi ◽  
Simone Lazzaroni ◽  
...  
Keyword(s):  
Gene Expression ◽  
Seed Germination ◽  
Medicago Truncatula ◽  
Sodium Butyrate

scholarly journals Bacterial Compound N,N-Dimethylhexadecylamine Modulates Expression of Iron Deficiency and Defense Response Genes in Medicago truncatula Independently of the Jasmonic Acid Pathway

Plants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 624 ◽  
Author(s):  
Vicente Montejano-Ramírez ◽  
Ernesto García-Pineda ◽  
Eduardo Valencia-Cantero
Keyword(s):  
Gene Expression ◽  
Salicylic Acid ◽  
Iron Deficiency ◽  
Jasmonic Acid ◽  
Pseudomonas Syringae ◽  
Medicago Truncatula ◽  
Abiotic Stresses ◽  
Biotic And Abiotic Stresses ◽  
Iron Deprivation ◽  
Iron Deficient

Plants face a variety of biotic and abiotic stresses including attack by microbial phytopathogens and nutrient deficiencies. Some bacterial volatile organic compounds (VOCs) activate defense and iron-deficiency responses in plants. To establish a relationship between defense and iron deficiency through VOCs, we identified key genes in the defense and iron-deprivation responses of the legume model Medicago truncatula and evaluated the effect of the rhizobacterial VOC N,N-dimethylhexadecylamine (DMHDA) on the gene expression in these pathways by RT-qPCR. DMHDA increased M. truncatula growth 1.5-fold under both iron-sufficient and iron-deficient conditions compared with untreated plants, whereas salicylic acid and jasmonic acid decreased growth. Iron-deficiency induced iron uptake and defense gene expression. Moreover, the effect was greater in combination with DMHDA. Salicylic acid, Pseudomonas syringae, jasmonic acid, and Botrytis cinerea had inhibitory effects on growth and iron response gene expression but activated defense genes. Taken together, our results showed that the VOC DMHDA activates defense and iron-deprivation pathways while inducing a growth promoting effect unlike conventional phytohormones, highlighting that DMHDA does not mimic jasmonic acid but induces an alternative pathway. This is a novel aspect in the complex interactions between biotic and abiotic stresses.

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