scholarly journals Oxidative Stress Produced by Paraquat Reduces Nitrogen Fixation in Soybean-Bradyrhizobium diazoefficiens Symbiosis by Decreasing Nodule Functionality

Nitrogen ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 30-40
Author(s):  
Germán Tortosa ◽  
Sergio Parejo ◽  
Juan J. Cabrera ◽  
Eulogio J. Bedmar ◽  
Socorro Mesa
Keyword(s):  
Oxidative Stress ◽  
Nitrogen Fixation ◽  
Symbiotic Nitrogen Fixation ◽  
Dry Weight ◽  
Fixed Nitrogen ◽  
Biotic And Abiotic Stresses ◽  
Free Living ◽  
Soybean Plants ◽  
Soil Metal ◽  
Free Living Conditions

Soybean (Glycine max.) is one of the most important legumes cultivated worldwide. Its productivity can be altered by some biotic and abiotic stresses like global warming, soil metal pollution or over-application of herbicides like paraquat (1,1’-dimethyl-4,4’-bipyridinium dichloride). In this study, the effect of oxidative stress produced by paraquat addition (0, 20, 50 and 100 µM) during plant growth on symbiotic nitrogen fixation (SNF) and functionality of Bradyrhizobium diazoefficiens-elicited soybean nodules were evaluated. Results showed that the 50 µM was the threshold that B. diazoefficiens can tolerate under free-living conditions. In symbiosis with soybean, the paraquat addition statistically reduced the shoot and root dry weight of soybean plants, and number and development of the nodules. SNF was negatively affected by paraquat, which reduced total nitrogen content and fixed nitrogen close to 50% when 100 µM was added. These effects were due to the impairment of nodule functionality and the increased oxidative status of the nodules, as revealed by the lower leghaemoglobin content and the higher lipid peroxidation in soybean nodules from paraquat-treated plants.

scholarly journals Sinorhizobium fredii HH103 RirA Is Required for Oxidative Stress Resistance and Efficient Symbiosis with Soybean

2019 ◽  
Vol 20 (3) ◽  
pp. 787 ◽  
Author(s):  
Juan Crespo-Rivas ◽  
Pilar Navarro-Gómez ◽  
Cynthia Alias-Villegas ◽  
Jie Shi ◽  
Tao Zhen ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitrogen Fixation ◽  
Rhizobium Leguminosarum ◽  
Symbiotic Nitrogen Fixation ◽  
Regulatory Protein ◽  
No Production ◽  
Broad Host Range ◽  
Wild Type ◽  
Iron Deficient ◽  
Soybean Plants

Members of Rhizobiaceae contain a homologue of the iron-responsive regulatory protein RirA. In different bacteria, RirA acts as a repressor of iron uptake systems under iron-replete conditions and contributes to ameliorate cell damage during oxidative stress. In Rhizobium leguminosarum and Sinorhizobium meliloti, mutations in rirA do not impair symbiotic nitrogen fixation. In this study, a rirA mutant of broad host range S. fredii HH103 has been constructed (SVQ780) and its free-living and symbiotic phenotypes evaluated. No production of siderophores could be detected in either the wild-type or SVQ780. The rirA mutant exhibited a growth advantage under iron-deficient conditions and hypersensitivity to hydrogen peroxide in iron-rich medium. Transcription of rirA in HH103 is subject to autoregulation and inactivation of the gene upregulates fbpA, a gene putatively involved in iron transport. The S. fredii rirA mutant was able to nodulate soybean plants, but symbiotic nitrogen fixation was impaired. Nodules induced by the mutant were poorly infected compared to those induced by the wild-type. Genetic complementation reversed the mutant’s hypersensitivity to H2O2, expression of fbpA, and symbiotic deficiency in soybean plants. This is the first report that demonstrates a role for RirA in the Rhizobium-legume symbiosis.

scholarly journals Development of RR soybean in function of glyphosate doses and Bradyrhizobium inoculation

2018 ◽  
Vol 22 (12) ◽  
pp. 854-858
Author(s):  
João W. Bossolani ◽  
Nadia M. Poloni ◽  
Edson Lazarini ◽  
João V. T. Bettiol ◽  
João A. Fischer Filho ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Symbiotic Nitrogen Fixation ◽  
Soybean Seeds ◽  
Leaf Chlorophyll ◽  
Outdoor Experiment ◽  
Glyphosate Herbicide ◽  
Soybean Plants ◽  
Biological Nitrogen ◽  
Different Doses ◽  
Herbicide Glyphosate

ABSTRACT Soybean has traditionally been produced in systems that include the use of herbicides, often in higher than recommended doses. The process of symbiotic nitrogen fixation in legumes can be hampered by these herbicides, both by direct effects on rhizobia and indirect effects on the host plant. An outdoor experiment was performed to evaluate the effects of different doses of a glyphosate herbicide on Bradyrhizobium strains and biological nitrogen fixation in soybean BMX Potência RR plants. Soybean seeds were inoculated with Bradyrhizobium elkanii (SEMIA 5019) and Bradyrhizobium japonicum (SEMIA 5079) strains in a commercial liquid inoculant. The treatments consisted of the absence and presence of Bradyrhizobium genotypes inoculated via seed and four doses of the herbicide glyphosate applied on the leaves (0, 1.0, 2.0, and 4.0 L ha-1 of the commercial product) at the V3 stage. The leaf chlorophyll index of inoculated RR soybean plants did not change on the application of glyphosate and, regardless of inoculation, plants had the capacity to recover from the effects of glyphosate application, without impaired development.

The Bradyrhizobium diazoefficiens two-component system NtrYX has a key role in symbiotic nitrogen fixation of soybean plants and cbb3 oxidase expression in bacteroids

2019 ◽  
Vol 440 (1-2) ◽  
pp. 167-183 ◽  
Author(s):  
María Florencia López ◽  
Valeria A. Hegel ◽  
María Jesús Torres ◽  
Alba Hidalgo García ◽  
María J. Delgado ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Symbiotic Nitrogen Fixation ◽  
Two Component System ◽  
Component System ◽  
Two Component ◽  
Soybean Plants

scholarly journals EFFETS DES SOUCHES DE RHIZOBIUM MELILOTI ET DES COUPES SUCCESSIVES DE LA LUZERNE (MEDICAGO SATIVA) SUR LA FIXATION SYMBIOTIQUE D’AZOTE

1977 ◽  
Vol 57 (2) ◽  
pp. 433-439 ◽  
Author(s):  
L. M. BORDELEAU ◽  
H. ANTOUN ◽  
R. A. LACHANCE
Keyword(s):  
Nitrogen Fixation ◽  
Medicago Sativa ◽  
Statistical Study ◽  
Symbiotic Nitrogen Fixation ◽  
Rhizobium Meliloti ◽  
Dry Weight ◽  
Indirect Measurement ◽  
Controlled Environment ◽  
Symbiotic Efficiency ◽  
Plant Yield

Symbiotic nitrogen fixation with 49 isolates of Rhizobium meliloti was studied under controlled environment with alfalfa cv. Saranac. It was shown that plant yield in dry weight can be used as an indirect measurement of nitrogen fixation, and as a criterion for selecting efficient strains of R. meliloti. Statistical study on yields of three cuttings has established that the second cutting gives the most necessary information to correctly evaluate the symbiotic efficiency of the isolates. Six very efficient strains were selected.

Détermination de l'identité isotopique de l'azote fixé par le Frankia associé au genre Alnus

1988 ◽  
Vol 66 (7) ◽  
pp. 1241-1247 ◽  
Author(s):  
A. M. Domenach ◽  
F. Kurdali ◽  
C. Danière ◽  
R. Bardin
Keyword(s):  
Nitrogen Fixation ◽  
Symbiotic Nitrogen Fixation ◽  
Alnus Glutinosa ◽  
Natural Ecosystem ◽  
Free Medium ◽  
Fixed Nitrogen ◽  
Aerial Parts ◽  
Reference Plant ◽  
N Enrichment ◽  
N Natural Abundance

To use the 15N natural abundance method to evaluate the symbiotic nitrogen fixation by actinorhizal trees, it is necessary to determine the isotopic identity of assimilated nitrogen from two sources: the soil and the air. This study reports an isotopic value of fixed nitrogen by two alder species (Alnus incana (L.) Moench and Alnus glutinosa (L.) Gaertn. growing on nitrogen-free medium in greenhouse experiments. The δ15N value of the aerial parts was −2. This value was stable with time and did not depend on the Frankia strains used. This value could be used to estimate the nitrogen fixation in the natural ecosystem. Other parameters such as the mobilization of nitrogen reserves and the choice of the reference plant must be investigated to apply this method. The nodules of these two alder species were enriched in 15N relative to the rest of the plant but there was no relationship between symbiotic effectiveness of Frankia strains and 15N enrichment of nodules. On the other hand, for naturally growing trees, an enrichment in 15N was found primarily in the vesicles of nodules that are the sites of nitrogen fixation.

Comparison of colony morphology, salt tolerance, and effectiveness in Rhizobium japonicum

1977 ◽  
Vol 23 (9) ◽  
pp. 1118-1122 ◽  
Author(s):  
Robert G. Upchurch ◽  
Gerald H. Elkan
Keyword(s):  
Nitrogen Fixation ◽  
Growth Rates ◽  
Host Plants ◽  
Symbiotic Nitrogen Fixation ◽  
Rhizobium Japonicum ◽  
Free Living ◽  
Relative Level ◽  
Colony Type ◽  
Large Colony ◽  
Small Colony

Four strains of Rhizobium japonicum, two of which produce slimy and non-slimy colony types and two others which produce large and small colony types, were isolated and cloned. All were infective and nodulated Lee soybean host plants. Each colony type was characterized as to its salt sensitivity to Na+ and K+ ions, relative level of symbiotic nitrogen fixation, and relative level of free-living nitrogen fixation. Growth studies performed in the presence of salts demonstrated that the non-slimy or small colony types were sensitive to salt with significantly depressed growth rates and cell yields. Growth rates and cell yields of slimy, large, colony types were relatively unaffected by salt. Both symbiotic and free-living (non-associative) nitrogen fixation analyses (by acetylene reduction) revealed that the non-slimy, small colonies were significantly more effective than slimy, large colonies.

scholarly journals Legume Symbiotic Nitrogen Fixation byβ-Proteobacteria Is Widespread inNature

2003 ◽  
Vol 185 (24) ◽  
pp. 7266-7272 ◽  
Author(s):  
Wen-Ming Chen ◽  
Lionel Moulin ◽  
Cyril Bontemps ◽  
Peter Vandamme ◽  
Gilles Béna ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Nitrogen Fixation ◽  
Phylogenetic Tree ◽  
Phylogenetic Diversity ◽  
Symbiotic Nitrogen Fixation ◽  
The Other ◽  
Gene Sequences ◽  
Free Living ◽  
Initial Discovery ◽  
Different Strains

ABSTRACT Following the initial discovery of two legume-nodulating Burkholderia strains (L. Moulin, A. Munive, B. Dreyfus, and C. Boivin-Masson, Nature 411:948-950, 2001), we identified as nitrogen-fixing legume symbionts at least 50 different strains of Burkholderia caribensis and Ralstonia taiwanensis, all belonging to the β-subclass of proteobacteria, thus extending the phylogenetic diversity of the rhizobia. R. taiwanensis was found to represent 93% of the Mimosa isolates in Taiwan, indicating thatβ -proteobacteria can be the specific symbionts of a legume. The nod genes of rhizobial β-proteobacteria (β-rhizobia) are very similar to those of rhizobia from theα -subclass (α-rhizobia), strongly supporting the hypothesis of the unique origin of common nod genes. Theβ -rhizobial nod genes are located on a 0.5-Mb plasmid, together with the nifH gene, in R. taiwanensis and Burkholderia phymatum. Phylogenetic analysis of available nodA gene sequences clustered β-rhizobial sequences in two nodA lineages intertwined with α-rhizobial sequences. On the other hand, theβ -rhizobia were grouped with free-living nitrogen-fixingβ -proteobacteria on the basis of the nifH phylogenetic tree. These findings suggest that β-rhizobia evolved from diazotrophs through multiple lateral nod gene transfers.

NON-SYMBIOTIC NITROGEN FIXATION IN SOME QUEBEC SOILS

1965 ◽  
Vol 11 (1) ◽  
pp. 29-38 ◽  
Author(s):  
P-C. Chang ◽  
R. Knowles
Keyword(s):  
Nitrogen Fixation ◽  
Symbiotic Nitrogen Fixation ◽  
Soil Types ◽  
Anaerobic Incubation ◽  
Nitrogen Fixing ◽  
Free Living ◽  
Aerobic Conditions ◽  
Bacterial Counts ◽  
Facultatively Anaerobic ◽  
Nitrogen Fixers

The occurrence of free-living nitrogen fixers, the potential for nitrogen fixation, and the correlation between the nitrogen-fixing capacities of the soils and bacterial counts were studied using representative Quebec soils.Clostridium occurred more frequently than did Azotobacter. Studies with N15showed that nitrogen fixation was more frequent under anaerobic than under aerobic conditions in all the soil types studied in their unamended state. The addition of glucose stimulated nitrogen fixation. During anaerobic incubation, nitrogen fixation was found to be correlated significantly with the increase in numbers of both total aerobes and Clostridia. The results suggested that facultatively anaerobic nitrogen fixers, and aerobic nitrogen fixers other than Azotobacter, were present.

Genetics of plant-microbe nitrogen-fixing symbiosis

1985 ◽  
Vol 85 (3-4) ◽  
pp. 239-252
Author(s):  
G. C. Machray ◽  
W. D. P. Stewart
Keyword(s):  
Nitrogen Fixation ◽  
Genetic Analysis ◽  
Symbiotic Nitrogen Fixation ◽  
Model System ◽  
Present Knowledge ◽  
Nitrogen Fixing ◽  
Free Living ◽  
Genetic Level ◽  
And Control ◽  
Control Of Expression

SynopsisA wide variety of plant-microbe nitrogen-fixing symbioses which include cyanobacteria as the nitrogenfixing partner exist. While some information has been gathered on the biochemical changes in the cyanobacterium upon entering into symbiosis, very little is known about the accompanying changes at the genetic level. Much of our present knowledge of the organisation and control of expression of nitrogenfixation (nif) genes is derived from studies of the free-living diazotroph Klebsiella pneumoniae. This organism thus provides a model system and source of experimental material for the genetic analysis of symbiotic nitrogen fixation. We describe the use of cloned K. pneumoniae genes for nitrogen fixation and its regulation in the genetic analysis' of nitrogen fixation in cyanobacteria which can enter into symbiosis with plants. These studies reveal some dissimilarities in the organisation of nif genes and raise questions as to the genetic control of nitrogen fixation in symbiosis.

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