Metallophore profiling of nitrogen-fixingFrankiaspp. to understand metal management in the rhizosphere of actinorhizal plants

Metallomics ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 810-821 ◽  
Author(s):  
Michael Deicke ◽  
Jan Frieder Mohr ◽  
Sébastien Roy ◽  
Peter Herzsprung ◽  
Jean-Philippe Bellenger ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Soil Bacteria ◽  
Actinorhizal Plants ◽  
Nitrogen Fixing

Frankiaspp. are widespread nitrogen-fixing and metallophore releasing soil bacteria, which often live in symbiosis with a broad spectrum of hosts.

scholarly journals FrankiaDiversity in Host Plant Root Nodules Is Independent of Abundance or Relative Diversity ofFrankiaPopulations in Corresponding Rhizosphere Soils

2017 ◽  
Vol 84 (5) ◽  
Author(s):  
Seifeddine Ben Tekaya ◽  
Trina Guerra ◽  
David Rodriguez ◽  
Jeffrey O. Dawson ◽  
Dittmar Hahn
Keyword(s):  
Host Plant ◽  
Root Nodule ◽  
Root Nodules ◽  
Actinorhizal Plants ◽  
Nodule Formation ◽  
Nitrogen Fixing ◽  
Content Type ◽  
Rhizosphere Soils ◽  
Root Nodule Formation ◽  
Host Infection

ABSTRACTActinorhizal plants form nitrogen-fixing root nodules in symbiosis with soil-dwelling actinobacteria within the genusFrankia, and specificFrankiataxonomic clusters nodulate plants in corresponding host infection groups. In same-soil microcosms, we observed that some host species were nodulated (Alnus glutinosa,Alnus cordata,Shepherdia argentea,Casuarina equisetifolia) while others were not (Alnus viridis,Hippophaë rhamnoides). Nodule populations were represented by eight different sequences ofnifHgene fragments. Two of these sequences characterized frankiae inS. argenteanodules, and three others characterized frankiae inA. glutinosanodules. Frankiae inA. cordatanodules were represented by five sequences, one of which was also found in nodules fromA. glutinosaandC. equisetifolia, while another was detected in nodules fromA. glutinosa. Quantitative PCR assays showed that vegetation generally increased the abundance of frankiae in soil, independently of the target gene (i.e.,nifHor the 23S rRNA gene). Targeted Illumina sequencing ofFrankia-specificnifHgene fragments detected 24 unique sequences from rhizosphere soils, 4 of which were also found in nodules, while the remaining 4 sequences in nodules were not found in soils. Seven of the 24 sequences from soils represented >90% of the reads obtained in most samples; the 2 most abundant sequences from soils were not found in root nodules, and only 2 of the sequences from soils were detected in nodules. These results demonstrate large differences between detectableFrankiapopulations in soil and those in root nodules, suggesting that root nodule formation is not a function of the abundance or relative diversity of specificFrankiapopulations in soils.IMPORTANCEThe nitrogen-fixing actinobacteriumFrankiaforms root nodules on actinorhizal plants, with members of specificFrankiataxonomic clusters nodulating plants in corresponding host infection groups. We assessedFrankiadiversity in root nodules of different host plant species, and we related specific populations to the abundance and relative distribution of indigenous frankiae in rhizosphere soils. Large differences were observed between detectableFrankiapopulations in soil and those in root nodules, suggesting that root nodule formation is not a function of the abundance or relative diversity of specificFrankiapopulations in soils but rather results from plants potentially selecting frankiae from the soil for root nodule formation. These data also highlight the necessity of using a combination of different assessment tools so as to adequately address methodological constraints that could produce contradictory data sets.

Erratum: Evidence that associated soil bacteria may influence root hair infection of actinorhizal plants by Frankia

1980 ◽  
Vol 26 (11) ◽  
pp. 1374-1374 ◽  
Author(s):  
Susan Knowlton ◽  
Alison Berry ◽  
John G. Torrey
Keyword(s):  
Root Hair ◽  
Soil Bacteria ◽  
Actinorhizal Plants ◽  
Root Hair Infection

Detoxification of mercury and organomercurials by nitrogen-fixing soil bacteria

1989 ◽  
Vol 14 (2) ◽  
pp. 173-182 ◽  
Author(s):  
S. Ray ◽  
R. Gachhui ◽  
K. Pahan ◽  
J. Chaudhury ◽  
A. Mandal
Keyword(s):  
Soil Bacteria ◽  
Nitrogen Fixing

scholarly journals How rhizobia adapt to the nodule environment

2021 ◽  
Author(s):  
Raphael Ledermann ◽  
Carolin C. M. Schulte ◽  
Philip S. Poole
Keyword(s):  
Nitrogen Fixation ◽  
Soil Bacteria ◽  
Root Nodule ◽  
Computational Modelling ◽  
Diverse Group ◽  
Nitrogen Fixing ◽  
The Core ◽  
Physiological Processes ◽  
Mutualistic Relationship ◽  
The Common

Rhizobia are a phylogenetically diverse group of soil bacteria that engage in mutualistic interactions with legume plants. Although specifics of the symbioses differ between strains and plants, all symbioses ultimately result in the formation of specialized root nodule organs which host the nitrogen-fixing microsymbionts called bacteroids. Inside nodules, bacteroids encounter unique conditions that necessitate global reprogramming of physiological processes and rerouting of their metabolism. Decades of research have addressed these questions using genetics, omics approaches, and more recently computational modelling. Here we discuss the common adaptations of rhizobia to the nodule environment that define the core principles of bacteroid functioning. All bacteroids are growth-arrested and perform energy-intensive nitrogen fixation fueled by plant-provided C4-dicarboxylates at nanomolar oxygen levels. At the same time, bacteroids are subject to host control and sanctioning that ultimately determine their fitness and have fundamental importance for the evolution of a stable mutualistic relationship.

scholarly journals From Intracellular Bacteria to Differentiated Bacteroids: Transcriptome and Metabolome Analysis inAeschynomeneNodules Using theBradyrhizobiumsp. Strain ORS285bclAMutant

2019 ◽  
Vol 201 (17) ◽  
Author(s):  
Florian Lamouche ◽  
Anaïs Chaumeret ◽  
Ibtissem Guefrachi ◽  
Quentin Barrière ◽  
Olivier Pierre ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcriptome Analysis ◽  
Soil Bacteria ◽  
Regulation Of Gene Expression ◽  
Nitrogen Fertilizers ◽  
Peptide Transporter ◽  
Intracellular Bacteria ◽  
Nitrogen Fixing ◽  
Wild Type ◽  
Free Living

ABSTRACTSoil bacteria called rhizobia trigger the formation of root nodules on legume plants. The rhizobia infect these symbiotic organs and adopt an intracellular lifestyle within the nodule cells, where they differentiate into nitrogen-fixing bacteroids. Several legume lineages force their symbionts into an extreme cellular differentiation, comprising cell enlargement and genome endoreduplication. The antimicrobial peptide transporter BclA is a major determinant of this process inBradyrhizobiumsp. strain ORS285, a symbiont ofAeschynomenespp. In the absence of BclA, the bacteria proceed until the intracellular infection of nodule cells, but they cannot differentiate into enlarged polyploid and functional bacteroids. Thus, thebclAnodule bacteria constitute an intermediate stage between the free-living soil bacteria and the nitrogen-fixing bacteroids. Metabolomics on whole nodules ofAeschynomene afrasperaandAeschynomene indicainfected with the wild type or thebclAmutant revealed 47 metabolites that differentially accumulated concomitantly with bacteroid differentiation. Bacterial transcriptome analysis of these nodules demonstrated that the intracellular settling of the rhizobia in the symbiotic nodule cells is accompanied by a first transcriptome switch involving several hundred upregulated and downregulated genes and a second switch accompanying the bacteroid differentiation, involving fewer genes but ones that are expressed to extremely elevated levels. The transcriptomes further suggested a dynamic role for oxygen and redox regulation of gene expression during nodule formation and a nonsymbiotic function of BclA. Together, our data uncover the metabolic and gene expression changes that accompany the transition from intracellular bacteria into differentiated nitrogen-fixing bacteroids.IMPORTANCELegume-rhizobium symbiosis is a major ecological process, fueling the biogeochemical nitrogen cycle with reduced nitrogen. It also represents a promising strategy to reduce the use of chemical nitrogen fertilizers in agriculture, thereby improving its sustainability. This interaction leads to the intracellular accommodation of rhizobia within plant cells of symbiotic organs, where they differentiate into nitrogen-fixing bacteroids. In specific legume clades, this differentiation process requires the bacterial transporter BclA to counteract antimicrobial peptides produced by the host. Transcriptome analysis ofBradyrhizobiumwild-type andbclAmutant bacteria in culture and in symbiosis withAeschynomenehost plants dissected the bacterial transcriptional response in distinct phases and highlighted functions of the transporter in the free-living stage of the bacterial life cycle.

scholarly journals Molecular Basis of Symbiotic Promiscuity

2000 ◽  
Vol 64 (1) ◽  
pp. 180-201 ◽  
Author(s):  
Xavier Perret ◽  
Christian Staehelin ◽  
William J. Broughton
Keyword(s):  
Host Range ◽  
Molecular Basis ◽  
Soil Bacteria ◽  
Molecular Mechanisms ◽  
Ecological Niches ◽  
Nitrogen Fixing ◽  
Nitrogen Fixing Bacteria ◽  
Nitrogen Input ◽  
Narrow Host Range

SUMMARY Eukaryotes often form symbioses with microorganisms. Among these, associations between plants and nitrogen-fixing bacteria are responsible for the nitrogen input into various ecological niches. Plants of many different families have evolved the capacity to develop root or stem nodules with diverse genera of soil bacteria. Of these, symbioses between legumes and rhizobia (Azorhizobium, Bradyrhizobium, Mesorhizobium, and Rhizobium) are the most important from an agricultural perspective. Nitrogen-fixing nodules arise when symbiotic rhizobia penetrate their hosts in a strictly controlled and coordinated manner. Molecular codes are exchanged between the symbionts in the rhizosphere to select compatible rhizobia from pathogens. Entry into the plant is restricted to bacteria that have the “keys” to a succession of legume “doors”. Some symbionts intimately associate with many different partners (and are thus promiscuous), while others are more selective and have a narrow host range. For historical reasons, narrow host range has been more intensively investigated than promiscuity. In our view, this has given a false impression of specificity in legume-Rhizobium associations. Rather, we suggest that restricted host ranges are limited to specific niches and represent specialization of widespread and more ancestral promiscuous symbioses. Here we analyze the molecular mechanisms governing symbiotic promiscuity in rhizobia and show that it is controlled by a number of molecular keys.

scholarly journals Draft Genome Sequence ofFrankiaStrain G2, a Nitrogen-Fixing Actinobacterium Isolated fromCasuarina equisetifoliaand Able To Nodulate Actinorhizal Plants of the OrderRhamnales

2016 ◽  
Vol 4 (3) ◽  
Author(s):  
Imen Nouioui ◽  
Maher Gtari ◽  
Markus Göker ◽  
Faten Ghodhbane-Gtari ◽  
Louis S. Tisa ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Draft Genome ◽  
Actinorhizal Plants ◽  
Draft Genome Sequence ◽  
Casuarina Equisetifolia ◽  
Nitrogen Fixing ◽  
Original Host

Frankiasp. strain G2 was originally isolated fromCasuarina equisetifoliaand is characterized by its ability to nodulate actinorhizal plants of theRhamnalesorder, but not its original host. It represents one of the largestFrankiagenomes so far sequenced (9.5 Mbp).

Nitrogen-Fixing Soil Bacteria Plus Mycorrhizal Fungi Improve Seed Yield and Quality Traits of Lentil (Lens culinaris Medik)

2019 ◽  
Vol 19 (3) ◽  
pp. 592-602 ◽  
Author(s):  
Reza Amirnia ◽  
Mahdi Ghiyasi ◽  
Sina Siavash Moghaddam ◽  
Amir Rahimi ◽  
Christos A. Damalas ◽  
...  
Keyword(s):  
Seed Yield ◽  
Mycorrhizal Fungi ◽  
Soil Bacteria ◽  
Lens Culinaris ◽  
Quality Traits ◽  
Nitrogen Fixing ◽  
Yield And Quality

scholarly journals Mercury resistance in nitrogen-fixing soil bacteria.

1989 ◽  
Vol 35 (2) ◽  
pp. 83-94 ◽  
Author(s):  
SATYAJIT RAY ◽  
RATAN GACHHUI ◽  
JAYASRI CHAUDHURI ◽  
A. MANDAL
Keyword(s):  
Soil Bacteria ◽  
Mercury Resistance ◽  
Nitrogen Fixing
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