scholarly journals The importance of Rhizobium, Agrobacterium, Bradyrhizobium, Herbaspirillum, Sinorhizobium in sustainable agricultural production

2021 ◽  
Vol 49 (3) ◽  
pp. 12183
Author(s):  
Mohamad H. SHAHRAJABIAN ◽  
Wenli SUN ◽  
Qi CHENG
Keyword(s):  
Nitrogen Fixation ◽  
Cell Division ◽  
Nitrogen Content ◽  
Root Hair ◽  
Agricultural Production ◽  
Soil Bacteria ◽  
Organic Nitrogen ◽  
Nitrogen Fixing ◽  
Review Of The Literature ◽  
Nod Factor

Rhizobia which are soil bacteria capable of symbiosis with legume plants in the root or stem nodules and perform nitrogen fixation. Rhizobial genera include Agrobacterium, Allorhizobium, Aminobacter, Azorhizobium, Bradyrhizobium, Devosia, Mesorhizobium, Methylobacterium, Microvirga, Ochrobacterum, Phyllobacterium, Rhizobium, Shinella and Ensifer (Sinorhizobium). Review of the literature was carried out using the keywords Rhizobium, Agrobacterium, Bradyrhizobium, Herbaspirillum and Sinorhizobium. Rhizobial nodulation symbioses steps are included flavonoid signaling, Nod factor induction, and Nod factor perception, root hair responses, rhizobial infection, cell division and formation of nitrogen-fixing nodule. Rhizobium improves sustainable production by boosting organic nitrogen content.

The effect of Inoculation and cobalt application on the growth of and nitrogen fixation by sweet lupins

1978 ◽  
Vol 29 (6) ◽  
pp. 1191 ◽  
Author(s):  
DL Chatel ◽  
AD Robson ◽  
JW Gartrell ◽  
MJ Dilworth
Keyword(s):  
Nitrogen Fixation ◽  
Cell Division ◽  
Plant Growth ◽  
Nitrogen Content ◽  
Lupinus Angustifolius ◽  
Fixed Nitrogen ◽  
Soil Application ◽  
Seed Inoculation

The response of sweet lupins, Lupinus angustifolius L., to a soil application of cobalt and to seed inoculation was examined in both field and glasshouse experiments. Plant growth was dependent on nodule-fixed nitrogen, and the addition of cobalt increased the nitrogen content and the growth of the lupins in the absence of inoculation. Bacteroids in the nodules of inoculated plants without cobalt were found to be fewer and longer than those with cobalt, which suggests that cobalt is involved in the mechanism of rhizobial cell division.

scholarly journals Nutrient-ColimitedTrichodesmiumas a Nitrogen Source or Sink in a Future Ocean

2017 ◽  
Vol 84 (3) ◽  
Author(s):  
Nathan G. Walworth ◽  
Fei-Xue Fu ◽  
Michael D. Lee ◽  
Xiaoni Cai ◽  
Mak A. Saito ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Nitrogen Source ◽  
Nitrogen Metabolism ◽  
Organic Nitrogen ◽  
Open Ocean ◽  
Nitrogen Fixing ◽  
Content Type ◽  
Nitrogen Inputs ◽  
Ocean Conditions ◽  
Nitrogen Scavenging

ABSTRACTNitrogen-fixing (N2) cyanobacteria provide bioavailable nitrogen to vast ocean regions but are in turn limited by iron (Fe) and/or phosphorus (P), which may force them to employ alternative nitrogen acquisition strategies. The adaptive responses of nitrogen fixers to global-change drivers under nutrient-limited conditions could profoundly alter the current ocean nitrogen and carbon cycles. Here, we show that the globally important N2fixerTrichodesmiumfundamentally shifts nitrogen metabolism toward organic-nitrogen scavenging following long-term high-CO2adaptation under iron and/or phosphorus (co)limitation. Global shifts in transcripts and proteins under high-CO2/Fe-limited and/or P-limited conditions include decreases in the N2-fixing nitrogenase enzyme, coupled with major increases in enzymes that oxidize trimethylamine (TMA). TMA is an abundant, biogeochemically important organic nitrogen compound that supports rapidTrichodesmiumgrowth while inhibiting N2fixation. In a future high-CO2ocean, this whole-cell energetic reallocation toward organic nitrogen scavenging and away from N2fixation may reduce new-nitrogen inputs byTrichodesmiumwhile simultaneously depleting the scarce fixed-nitrogen supplies of nitrogen-limited open-ocean ecosystems.IMPORTANCETrichodesmiumis among the most biogeochemically significant microorganisms in the ocean, since it supplies up to 50% of the new nitrogen supporting open-ocean food webs. We usedTrichodesmiumcultures adapted to high-CO2conditions for 7 years, followed by additional exposure to iron and/or phosphorus (co)limitation. We show that “future ocean” conditions of high CO2and concurrent nutrient limitation(s) fundamentally shift nitrogen metabolism away from nitrogen fixation and instead toward upregulation of organic nitrogen-scavenging pathways. We show that the responses ofTrichodesmiumto projected future ocean conditions include decreases in the nitrogen-fixing nitrogenase enzymes coupled with major increases in enzymes that oxidize the abundant organic nitrogen source trimethylamine (TMA). Such a shift toward organic nitrogen uptake and away from nitrogen fixation may substantially reduce new-nitrogen inputs byTrichodesmiumto the rest of the microbial community in the future high-CO2ocean, with potential global implications for ocean carbon and nitrogen cycling.

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.

Synthesis of bradyrhizose, a unique inositol-fused monosaccharide relevant to a Nod-factor independent nitrogen fixation

2015 ◽  
Vol 51 (32) ◽  
pp. 6964-6967 ◽  
Author(s):  
Wei Li ◽  
Alba Silipo ◽  
Antonio Molinaro ◽  
Biao Yu
Keyword(s):  
Nitrogen Fixation ◽  
Nitrogen Fixing ◽  
Nod Factor

Bradyrhizose, a unique C10 monosaccharide relevant to a Nod-factor independent nitrogen-fixing symbiosis, was synthesized.

scholarly journals Genome Analysis Suggests that the Soil Oligotrophic Bacterium Agromonas oligotrophica (Bradyrhizobium oligotrophicum) Is a Nitrogen-Fixing Symbiont of Aeschynomene indica

2013 ◽  
Vol 79 (8) ◽  
pp. 2542-2551 ◽  
Author(s):  
Takashi Okubo ◽  
Shohei Fukushima ◽  
Manabu Itakura ◽  
Kenshiro Oshima ◽  
Aphakorn Longtonglang ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Phylogenetic Analyses ◽  
Gc Content ◽  
Gene Clusters ◽  
Nodule Development ◽  
Nitrogen Fixing ◽  
Circular Chromosome ◽  
Nod Factor ◽  
Content Type ◽  
Oligotrophic Bacterium

ABSTRACTAgromonas oligotrophica(Bradyrhizobium oligotrophicum) S58Tis a nitrogen-fixing oligotrophic bacterium isolated from paddy field soil that is able to grow in extra-low-nutrient environments. Here, the complete genome sequence of S58 was determined. The S58 genome was found to comprise a circular chromosome of 8,264,165 bp with an average GC content of 65.1% lackingnodABCgenes and the typical symbiosis island. The genome showed a high level of similarity to the genomes ofBradyrhizobiumsp. ORS278 andBradyrhizobiumsp. BTAi1, including nitrogen fixation and photosynthesis gene clusters, which nodulate an aquatic legume plant,Aeschynomene indica, in a Nod factor-independent manner. Although nonsymbiotic (brady)rhizobia are significant components of rhizobial populations in soil, we found that most genes important for nodule development (ndv) and symbiotic nitrogen fixation (nifandfix) withA. indicawere well conserved between the ORS278 and S58 genomes. Therefore, we performed inoculation experiments with fiveA. oligotrophicastrains (S58, S42, S55, S72, and S80). Surprisingly, all five strains ofA. oligotrophicaformed effective nitrogen-fixing nodules on the roots and/or stems ofA. indica, with differentiated bacteroids. Nonsymbiotic (brady)rhizobia are known to be significant components of rhizobial populations without a symbiosis island or symbiotic plasmids in soil, but the present results indicate that soil-dwellingA. oligotrophicagenerally possesses the ability to establish symbiosis withA. indica. Phylogenetic analyses suggest that Nod factor-independent symbiosis withA. indicais a common trait ofnodABC- and symbiosis island-lacking strains within the members of the photosyntheticBradyrhizobiumclade, includingA. oligotrophica.

Ethylene provides positional information on cortical cell division but is not involved in Nod factor-induced root hair tip growth in Rhizobium-legume interaction

Development ◽  
1997 ◽  
Vol 124 (9) ◽  
pp. 1781-1787 ◽  
Author(s):  
R. Heidstra ◽  
W.C. Yang ◽  
Y. Yalcin ◽  
S. Peck ◽  
A.M. Emons ◽  
...  
Keyword(s):  
Cell Division ◽  
Root Hair ◽  
Rhizobium Leguminosarum ◽  
Tip Growth ◽  
Cortical Cell ◽  
Acc Oxidase ◽  
Positional Information ◽  
Nod Factors ◽  
Nod Factor ◽  
Root Hair Deformation

Nod factors secreted by Rhizobium leguminosarum bv. viciae induce root hair deformation, involving a reinitiation of tip growth, and the formation of nodule primordia in Vicia sativa (vetch). Ethylene is a potent inhibitor of cortical cell division, an effect that can be counteracted by applying silver ions (Ag+) or aminoethoxy-vinylglycine (AVG). In contrast to the inhibitory effect on cortical cell division, ethylene promotes the formation of root hairs (which involves tip growth) in the root epidermis of Arabidopsis. We investigate the possible paradox concerning the action of ethylene, putatively promoting Nod factor induced tip growth whilst, at the same time, inhibiting cortical cell division. We show, by using the ethylene inhibitors AVG and Ag+, that ethylene has no role in the reinitiation of root hair tip growth induced by Nod factors (root hair deformation) in vetch. However, root hair formation is controlled, at least in part, by ethylene. Furthermore, we show that ACC oxidase, which catalizes the last step in ethylene biosynthesis, is expressed in the cell layers opposite the phloem in that part of the root where nodule primordia are induced upon inoculation with Rhizobium. Therefore, we test whether endogenously produced ethylene provides positional information controlling the site where nodule primordia are formed by determining the position of nodules formed on pea roots grown in the presence of AVG or Ag+.

scholarly journals Plasmids Related to the Symbiotic Nitrogen Fixation Are Not Only Cooperated Functionally but Also May Have Evolved over a Time Span in Family Rhizobiaceae

2020 ◽  
Vol 12 (11) ◽  
pp. 2002-2014
Author(s):  
Ling-Ling Yang ◽  
Zhao Jiang ◽  
Yan Li ◽  
En-Tao Wang ◽  
Xiao-Yang Zhi
Keyword(s):  
Nitrogen Fixation ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Symbiotic Nitrogen Fixation ◽  
Gene Families ◽  
Time Span ◽  
Soil Conditions ◽  
Gene Gain ◽  
Nitrogen Fixing ◽  
Pan Genome

Abstract Rhizobia are soil bacteria capable of forming symbiotic nitrogen-fixing nodules associated with leguminous plants. In fast-growing legume-nodulating rhizobia, such as the species in the family Rhizobiaceae, the symbiotic plasmid is the main genetic basis for nitrogen-fixing symbiosis, and is susceptible to horizontal gene transfer. To further understand the symbioses evolution in Rhizobiaceae, we analyzed the pan-genome of this family based on 92 genomes of type/reference strains and reconstructed its phylogeny using a phylogenomics approach. Intriguingly, although the genetic expansion that occurred in chromosomal regions was the main reason for the high proportion of low-frequency flexible gene families in the pan-genome, gene gain events associated with accessory plasmids introduced more genes into the genomes of nitrogen-fixing species. For symbiotic plasmids, although horizontal gene transfer frequently occurred, transfer may be impeded by, such as, the host’s physical isolation and soil conditions, even among phylogenetically close species. During coevolution with leguminous hosts, the plasmid system, including accessory and symbiotic plasmids, may have evolved over a time span, and provided rhizobial species with the ability to adapt to various environmental conditions and helped them achieve nitrogen fixation. These findings provide new insights into the phylogeny of Rhizobiaceae and advance our understanding of the evolution of symbiotic nitrogen fixation.

scholarly journals Genomic characterization and computational phenotyping of nitrogen-fixing bacteria isolated from Colombian sugarcane fields

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Luz K. Medina-Cordoba ◽  
Aroon T. Chande ◽  
Lavanya Rishishwar ◽  
Leonard W. Mayer ◽  
Lina C. Valderrama-Aguirre ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Nitrogen Fixation ◽  
Plant Growth ◽  
Phosphate Solubilization ◽  
Nitrogen Fixing ◽  
Nitrogen Fixing Bacteria ◽  
Promising Tool ◽  
A Genome ◽  
Plant Growth Promoting ◽  
Growth Promoting

AbstractPrevious studies have shown the sugarcane microbiome harbors diverse plant growth promoting microorganisms, including nitrogen-fixing bacteria (diazotrophs), which can serve as biofertilizers. The genomes of 22 diazotrophs from Colombian sugarcane fields were sequenced to investigate potential biofertilizers. A genome-enabled computational phenotyping approach was developed to prioritize sugarcane associated diazotrophs according to their potential as biofertilizers. This method selects isolates that have potential for nitrogen fixation and other plant growth promoting (PGP) phenotypes while showing low risk for virulence and antibiotic resistance. Intact nitrogenase (nif) genes and operons were found in 18 of the isolates. Isolates also encode phosphate solubilization and siderophore production operons, and other PGP genes. The majority of sugarcane isolates showed uniformly low predicted virulence and antibiotic resistance compared to clinical isolates. Six strains with the highest overall genotype scores were experimentally evaluated for nitrogen fixation, phosphate solubilization, and the production of siderophores, gibberellic acid, and indole acetic acid. Results from the biochemical assays were consistent and validated computational phenotype predictions. A genotypic and phenotypic threshold was observed that separated strains by their potential for PGP versus predicted pathogenicity. Our results indicate that computational phenotyping is a promising tool for the assessment of bacteria detected in agricultural ecosystems.

Sign in / Sign up

Export Citation Format

Share Document