Journal articles on the topic 'Bradyrhizobium japonicum; Nitrogen – Fixation; Rhizobium'
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1
Baginsky, Cecilia, Belén Brito, Juan Imperial, José-Manuel Palacios, and Tomás Ruiz-Argüeso. "Diversity and Evolution of Hydrogenase Systems in Rhizobia." Applied and Environmental Microbiology 68, no. 10 (October 2002): 4915–24. http://dx.doi.org/10.1128/aem.68.10.4915-4924.2002.
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ABSTRACT Uptake hydrogenases allow rhizobia to recycle the hydrogen generated in the nitrogen fixation process within the legume nodule. Hydrogenase (hup) systems in Bradyrhizobium japonicum and Rhizobium leguminosarum bv. viciae show highly conserved sequence and gene organization, but important differences exist in regulation and in the presence of specific genes. We have undertaken the characterization of hup gene clusters from Bradyrhizobium sp. (Lupinus), Bradyrhizobium sp. (Vigna), and Rhizobium tropici and Azorhizobium caulinodans strains with the aim of defining the extent of diversity in hup gene composition and regulation in endosymbiotic bacteria. Genomic DNA hybridizations using hupS, hupE, hupUV, hypB, and hoxA probes showed a diversity of intraspecific hup profiles within Bradyrhizobium sp. (Lupinus) and Bradyrhizobium sp. (Vigna) strains and homogeneous intraspecific patterns within R. tropici and A. caulinodans strains. The analysis also revealed differences regarding the possession of hydrogenase regulatory genes. Phylogenetic analyses using partial sequences of hupS and hupL clustered R. leguminosarum and R. tropici hup sequences together with those from B. japonicum and Bradyrhizobium sp. (Lupinus) strains, suggesting a common origin. In contrast, Bradyrhizobium sp. (Vigna) hup sequences diverged from the rest of rhizobial sequences, which might indicate that those organisms have evolved independently and possibly have acquired the sequences by horizontal transfer from an unidentified source.
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Bhagwat, Arvind A., and Donald L. Keister. "Synthesis of β-glucans by Bradyrhizobium japonicum and Rhizobium fredii." Canadian Journal of Microbiology 38, no. 6 (June 1, 1992): 510–14. http://dx.doi.org/10.1139/m92-084.
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Particulate enzyme preparations from Rhizobium and Bradyrhizobium synthesize β-glucans when incubated with uridine diphosphate glucose (UDP-glucose) and a divalent cation. Synthesis of β-1,2-linked glucans in Rhizobium fredii involves the product of the ndvB gene, a 319-kDa membrane protein, which is labeled with [14C]glucose from UDP-[14C]glucose as previously demonstrated in Rhizobium meliloti and Agrobacterium sp. Bradyrhizobium japonicum synthesize β-1,3- and β-1,6-linked glucans of a lower molecular weight than those synthesized by R. meliloti. In comparative experiments, no evidence was found for a protein-bound intermediate in B. japonicum. The ndvB gene of R. fredii was mobilized to B. japonicum and the gene was expressed, as evidenced by appearance of a large membrane protein (ca. 319 kDa) which was labeled with UDP-[14C]glucose in vitro. Key words: soybean, nitrogen fixation, β-glucan, Bradyrhizobium, Rhizobium.
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Nagata, Maki, Ei-ichi Murakami, Yoshikazu Shimoda, Fuyuko Shimoda-Sasakura, Ken-ichi Kucho, Akihiro Suzuki, Mikiko Abe, Shiro Higashi, and Toshiki Uchiumi. "Expression of a Class 1 Hemoglobin Gene and Production of Nitric Oxide in Response to Symbiotic and Pathogenic Bacteria in Lotus japonicus." Molecular Plant-Microbe Interactions® 21, no. 9 (September 2008): 1175–83. http://dx.doi.org/10.1094/mpmi-21-9-1175.
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Symbiotic nitrogen fixation by the collaboration between leguminous plants and rhizobia is an important system in the global nitrogen cycle, and some molecular aspects during the early stage of host-symbiont recognition have been revealed. To understand the responses of a host plant against various bacteria, we examined expression of hemoglobin (Hb) genes and production of nitric oxide (NO) in Lotus japonicus after inoculation with rhizobia or plant pathogens. When the symbiotic rhizobium Mesorhizobium loti was inoculated, expression of LjHb1 and NO production were induced transiently in the roots at 4 h after inoculation. In contrast, inoculation with the nonsymbiotic rhizobia Sinorhizobium meliloti and Bradyrhizobium japonicum induced neither expression of LjHb1 nor NO production. When L. japonicus was inoculated with plant pathogens (Ralstonia solanacearum or Pseudomonas syringae), continuous NO production was observed in roots but induction of LjHb1 did not occur. These results suggest that modulation of NO levels and expression of class 1 Hb are involved in the establishment of the symbiosis.
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Sajid, G. M., and W. F. Campbell. "EVALUATION OF HUP+, HUP– AND A TRANSCONJUGANT RHIZOBIUM ON YIELD, NITROGEN FIXATION, AND UPTAKE HYDROGENASE ACTIVITY IN SELECTED CHICKPEA CULTIVARS." HortScience 31, no. 3 (June 1996): 324e—324. http://dx.doi.org/10.21273/hortsci.31.3.324e.
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Evolution of hydrogen gas (H2) during N2 reduction in root nodules results in inefficient use of energy needed for N2 fixation. Cultivars of chickpea (Cicer arietinum L.) were inoculated with Rhizobium strains with and without genes for uptake hydrogenase (Hup) activity. H2 evolution, acetylene reduction activity, and uptake hydrogenase (Hup) activity were assayed on the resulting nodules. The Hup– strains produced higher plant yields than the Hup+ strains. The +N controls produced significantly higher yields than the –N controls and plants inoculated with Rhizobium strains. Hydrogen uptake activity by Rhizobium strains was influenced by the cultivar characteristics. Expression of the plasmid-borne hup genes (pHU52) of Bradyrhizobium japonicum was modified by the host cultivar. The average nodule fresh weight and shoot and root dry weights of the cultivars significantly increased following inoculation with the transconjugant Hup+ Rhizobium strain. Thus, biological N2 fixation may be enhanced by selecting Rhizobium strains that are appropriately matched to the particular cultivar. Incorporation of transconjugant Hup+ genes can increase rhizobial activity.
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Masterson, R. V., R. K. Prakash, and A. G. Atherly. "Conservation of symbiotic nitrogen fixation gene sequences in Rhizobium japonicum and Bradyrhizobium japonicum." Journal of Bacteriology 163, no. 1 (1985): 21–26. http://dx.doi.org/10.1128/jb.163.1.21-26.1985.
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Castellano-Hinojosa, Antonio, Christoph Mora, and Sarah L. Strauss. "Native Rhizobia Improve Plant Growth, Fix N2, and Reduce Greenhouse Emissions of Sunnhemp More than Commercial Rhizobia Inoculants in Florida Citrus Orchards." Plants 11, no. 22 (November 8, 2022): 3011. http://dx.doi.org/10.3390/plants11223011.
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Sunnhemp (Crotalaria juncea L.) is an important legume cover crop used in tree cropping systems, where there is increased interest by growers to identify rhizobia to maximize soil nitrogen (N) inputs. We aimed to isolate and identify native rhizobia and compare their capabilities with non-native rhizobia from commercial inoculants to fix atmospheric dinitrogen (N2), produce and reduce nitrous oxide (N2O), and improve plant growth. Phylogenetic analyses of sequences of the 16S rRNA and recA, atpD, and glnII genes showed native rhizobial strains belonged to Rhizobium tropici and the non-native strain to Bradyrhizobium japonicum. Plant nodulation tests, sequencing of nodC and nifH genes, and the acetylene-dependent ethylene production assay confirmed the capacity of all strains to nodulate sunnhemp and fix N2. Inoculation with native rhizobial strains resulted in significant increases in root and shoot weight and total C and N contents in the shoots, and showed greater N2-fixation rates and lower emissions of N2O compared to the non-native rhizobium. Our results suggest that native rhizobia improve plant growth, fix N2, and reduce greenhouse emissions of sunnhemp more than commercial rhizobia inoculants in Florida citrus orchards.
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El-Din, Abdel Kader Yousef Gamal. "A succinate transport mutant of Bradyrhizobium japonicum forms ineffective nodules on soybeans." Canadian Journal of Microbiology 38, no. 3 (March 1, 1992): 230–34. http://dx.doi.org/10.1139/m92-039.
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Biochemical evidence has shown that dicarboxylic acids actively support symbiotic nitrogen fixation by both fast- and slow-growing Rhizobium. Mutants defective in the active uptake of succinate have been previously described only in species of the fast-growing rhizobium. This article is a report on the isolation of mutants defective in dicarboxylate transport in a slow-growing species of rhizobium, Bradyrhizobium japonicum. One of these presumptive dicarboxylate transport mutants, GTS, was characterized further. Cultured GTS was unable to accumulate [14C]succinate above background levels but possessed normal rates of malate dehydrogenase, fumarase, and hydroxybutyrate dehydrogenase activities. When inoculated onto soybeans, GTS produced a Nod+, Fix− phenotype. The bacteroids isolated from these nodules failed to accumulate labelled succinate. Electron micrographs of nodules formed by inoculation with GTS appeared normal with the exceptions of more prominent peribacteroid spaces in the infected cells and the appearance of starch granules in the noninfected cells. The phenotypical and morphological changes observed for B. japonicum are similar to those previously reported for the fast-growing species. Key words: Fix−, mutant, Rhizobium, succinate, transport.
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Krutуlo, D. V. "FUNCTIONING OF SYMBIOTIC SYSTEMS OF COWPEA – NODULE BACTERIA." Agriciltural microbiology 12 (March 22, 2011): 46–58. http://dx.doi.org/10.35868/1997-3004.12.46-58.
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The nodule bacteria were isolated from the nodules of cowpea. On the basis of phenotypical properties these rhizobia were referred to slow growing bacteria of Bradyrhizobium genus. Interaction features of cowpea with the nodule bacteria of cowpea (Bradyrhizobium sp. (Vigna)) and soybean (Bradyrhizobium japonicum) on nitrogen-free substrate and in soil culture were studied. It was established that the cowpea rhizobia strains possess high specificity to the host plant, promote symbiotic nitrogen fixation activity in 1,8-2,6 times and increase plants aboveground mass yield in 1,4-3,4 times, in comparison with control. The significant positive influence of the active soybean microsymbiont Bradyrhizobium japonicum 46 on the growth and development of cowpea was shown.
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Brechenmacher, Laurent, Moon-Young Kim, Marisol Benitez, Min Li, Trupti Joshi, Bernarda Calla, Mei Phing Lee, et al. "Transcription Profiling of Soybean Nodulation by Bradyrhizobium japonicum." Molecular Plant-Microbe Interactions® 21, no. 5 (May 2008): 631–45. http://dx.doi.org/10.1094/mpmi-21-5-0631.
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Legumes interact with nodulating bacteria that convert atmospheric nitrogen into ammonia for plant use. This nitrogen fixation takes place within root nodules that form after infection of root hairs by compatible rhizobia. Using cDNA microarrays, we monitored gene expression in soybean (Glycine max) inoculated with the nodulating bacterium Bradyrhizobium japonicum 4, 8, and 16 days after inoculation, timepoints that coincide with nodule development and the onset of nitrogen fixation. This experiment identified several thousand genes that were differentially expressed in response to B. japonicum inoculation. Expression of 27 genes was analyzed by quantitative reverse transcriptase-polymerase chain reaction, and their expression patterns mimicked the microarray results, confirming integrity of analyses. The microarray results suggest that B. japonicum reduces plant defense responses during nodule development. In addition, the data revealed a high level of regulatory complexity (transcriptional, post-transcriptional, translational, post-translational) that is likely essential for development of the symbiosis and adjustment to an altered nutritional status.
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Streeter, John G., and Arvind Bhagwat. "Biosynthesis of trehalose from maltooligosaccharides in Rhizobia." Canadian Journal of Microbiology 45, no. 8 (August 15, 1999): 716–21. http://dx.doi.org/10.1139/w99-050.
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Previously, the enzymes for trehalose synthesis that are present in Escherichia coli were demonstrated in Bradyrhizobium japonicum and B. elkanii. An alternative mechanism recently reported for the synthesis of trehalose from maltooligosaccharides was considered based on the fact that high concentrations of sugars in liquid culture stimulated the accumulation of trehalose. An assay for the synthesis of trehalose from maltooligosaccharides using crude, gel-filtered protein preparations was developed. Analysis of a variety of the Rhizobiaceae indicates that the "maltooligosaccharide mechanism" is present in B. japonicum, B. elkanii, Rhizobium sp. NGR234, Sinorhizobium meliloti, R. tropici A, R. leguminosarum bv viciae, R. l. bv trifolii, and Azorhizobium caulinodans. Synthesis of trehalose from maltooligosaccharide could not be detected in R. tropici B or R. etli. With these two exceptions, it is suggested that rhizobia have two mechanisms for the biosynthesis of trehalose.Key words: maltooligosyl trehalose synthase, maltooligosyl trehalose trehalohydrolase, symbiotic nitrogen fixation.
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Melnykova, N. M., and S. Ya Kots. "EFFECT OF GOAT’S-RUE RHIZOBIA ON THE FORMATION AND FUNCTIONING OF THE SOYBEAN – BRADYRHIZOBIUM JAPONICUM 634B SYMBIOSIS." Agriciltural microbiology 29 (October 17, 2019): 29–36. http://dx.doi.org/10.35868/1997-3004.29.29-36.
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Objective. Study the peculiarities of nodule formation upon the formation of the symbiotic sys-tem soybean-Bradyrhizobium japonicum 634b, as well as the symbiotic nitrogen-fixation ability and plant growth and development under the influence of goat’s-rue rhizobia. Methods. Microbiologi-cal, physiological, statistical, gas chromatography. Results. In green house experiments, using sand as a substrate for growing plants, the mixed microbial cultures combining soybean nodule bacteria B. japonicum 634b and goat’s-rue nodule bacteria R. galegae 0702 or R. galegae 0703 in the ratio of 1 : 1 differed from the monoculture bradyrhizobium by their influence on the nodulation, nitro-gen-fixation ability of soybean-rhizobial symbiosis and development of soybean plants (variety Almaz). Increased nodulation activity in the primordial leaf and budding phases, as well as a signif-icant decrease in the level of symbiosis nitrogen fixation during budding, were observed when used in binary bacterial compositions of strain R. galegae 0703. These rhizobia of goat’s-rue suppressed the development of the root system of soybeans, but had no significant effect on the formation of the aerial part of the plants throughout the observation period. R. galegae 0702 strain slightly slowed the formation of nodules by bacteria in the primordial leaf phase, which caused a decrease in the number of soybean plants that formed symbiosis with B. japonicum 634b. Goat’s-rue nodule bacte-ria R. galegae 0702 improved the formation of the root system, and stimulated the growth and de-velopment of the aerial part of the macro symbiont in the phase of two trigeminal leaves. Conclu-sion. Combined inoculation of the rhizobia of goat’s-rue with nodule bacteria B. japonicum 634b showed a multidirectional effect on the formation of symbiosis by soybean plants of variety Almaz and functioning of soybean rhizobial symbiosis. The nature of the influence of R. galegae depended on their strain affiliation.
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Oh, Hye-Sook, Jong-Yoon Chun, Myung-Sok Lee, Kyung-Hee Min, Suk-Ha Lee, and Choong-Ill Cheon. "Role of hsfA gene on host-specificity by Bradyrhizobium japonicum in a broad range of tropical legumes." Canadian Journal of Microbiology 46, no. 1 (December 17, 1999): 81–84. http://dx.doi.org/10.1139/w99-111.
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Bradyrhizobium japonicum mutant strain NAD163, containing a 30-kb deletion mutant encompassing the hsfA gene, was inoculated onto a broad range of legume species to test host-specificity. Most legume species formed ineffective nodules except Vigna angularis var. Chibopat and Glycine max var. Pureunkong. A hsfA insertion mutant, BjjC211, gave similar results to strain NAD163, implying that many legume species require HsfA for host-specific nitrogen fixation. To determine whether other genes in the deleted region of NAD163 are also necessary, the hsfA gene was conjugally transferred into the NAD163 mutant. The transconjugant formed effective nodules on the host legume plants, which earlier had formed ineffective nodules with mutant NAD163. Thus, we conclude that the hsfA gene in the 30-kb region is the only factor responsible for host-specific nitrogen fixation in legume plants.Key words: host-specific nitrogen fixation, legume-Rhizobium symbiosis, hsfA gene, host-specificity.
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Green, Laura S., James K. Waters, Shanelle Ko, and David W. Emerich. "Comparative analysis of the Bradyrhizobium japonicum sucA region." Canadian Journal of Microbiology 49, no. 4 (March 1, 2003): 237–43. http://dx.doi.org/10.1139/w03-031.
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To study the adjustments made to the tricarboxylic acid cycle during symbiosis of nitrogen-fixing rhizobia with their host legumes, we have characterized the genes encoding the α-ketoglutarate dehydrogenase enzyme complex in Bradyrhizobium japonicum. The genes were arranged in the order sucA-sucB-scdA-lpdA, where scdA represents a short-chain dehydrogenase gene (GenBank accession No. AY049030). All four genes appeared to be co-transcribed, an arrangement that is so far unique to B. japonicum. The mdh gene, encoding malate dehydrogenase, was located upstream of the sucA operon, and its primary transcript appeared to be monocistronic. Primer extension indicated that the sucA operon and mdh were transcribed from typical housekeeping promoters.Key words: nitrogen fixation, Bradyrhizobium, α-ketoglutarate dehydrogenase, sucA.
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González, Juan E., and Melanie M. Marketon. "Quorum Sensing in Nitrogen-Fixing Rhizobia." Microbiology and Molecular Biology Reviews 67, no. 4 (December 2003): 574–92. http://dx.doi.org/10.1128/mmbr.67.4.574-592.2003.
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SUMMARY Members of the rhizobia are distinguished for their ability to establish a nitrogen-fixing symbiosis with leguminous plants. While many details of this relationship remain a mystery, much effort has gone into elucidating the mechanisms governing bacterium-host recognition and the events leading to symbiosis. Several signal molecules, including plant-produced flavonoids and bacterially produced nodulation factors and exopolysaccharides, are known to function in the molecular conversation between the host and the symbiont. Work by several laboratories has shown that an additional mode of regulation, quorum sensing, intercedes in the signal exchange process and perhaps plays a major role in preparing and coordinating the nitrogen-fixing rhizobia during the establishment of the symbiosis. Rhizobium leguminosarum, for example, carries a multitiered quorum-sensing system that represents one of the most complex regulatory networks identified for this form of gene regulation. This review focuses on the recent stream of information regarding quorum sensing in the nitrogen-fixing rhizobia. Seminal work on the quorum-sensing systems of R. leguminosarum bv. viciae, R. etli, Rhizobium sp. strain NGR234, Sinorhizobium meliloti, and Bradyrhizobium japonicum is presented and discussed. The latest work shows that quorum sensing can be linked to various symbiotic phenomena including nodulation efficiency, symbiosome development, exopolysaccharide production, and nitrogen fixation, all of which are important for the establishment of a successful symbiosis. Many questions remain to be answered, but the knowledge obtained so far provides a firm foundation for future studies on the role of quorum-sensing mediated gene regulation in host-bacterium interactions.
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Oehrle, Nathan W., Dale B. Karr, Robert J. Kremer, and David W. Emerich. "Enhanced attachment of Bradyrhizobium japonicum to soybean through reduced root colonization of internally seedborne microorganisms." Canadian Journal of Microbiology 46, no. 7 (July 1, 2000): 600–606. http://dx.doi.org/10.1139/w00-030.
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Internally seedborne microorganisms are those surviving common surface sterilization procedures. Such microbes often colonize the radicle surface of a germinating soybean (Glycine max) seed, introducing an undefined parameter into studies on attachment and infection by Bradyrhizobium japonicum. Bacterial isolates from surface-sterilized soybean seed, cv. Williams 82 and cv. Maverick, used in our studies, were identified as Agrobacterium radiobacter, Aeromonas sp., Bacillus spp., Chryseomonas luteola, Flavimonas oryzihabitans, and Sphingomonas paucimobilis. Growth of these microbes during seed germination was reduced by treating germinating seeds with 500 µg/mL penicillin G. The effects of this antibiotic on seedling development and on B. japonicum 2143 attachment, nodulation, and nitrogen fixation are reported here. Penicillin G treatment of seeds did not reduce seed germination or root tip growth, or affect seedling development. No differences in nodulation kinetics, nitrogen fixation onset or rates were observed. However, the number of B. japonicum attached to treated intact seedlings was enhanced 200-325%, demonstrating that other root-colonizing bacteria can interfere with rhizobial attachment. Penicillin G treatment of soybean seedlings can be used to reduce the root colonizing microbes, which introduce an undefined parameter into studies of attachment of B. japonicum to the soybean root, without affecting plant development.Key words: internally seedborne microorganisms, penicillin G, Bradyrhizobium japonicum, microbial attachment, soybean (Glycine max).
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K, Kannan, Rajesh Kannan V, Shibinaya N, and Umamaheswari M. "Control Of Fusarium Wilt Disease In Cowpea Plant (Vigna Unguiculata L.). Using Secondary Metabolites Produced In Bradyrhizobium Japonicum." Kongunadu Research Journal 6, no. 2 (December 16, 2019): 28–36. http://dx.doi.org/10.26524/krj298.
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Rhizobium known for its nitrogen fixation and plant growth promoting capabilities which is symbiotically associative with legume plants. So forth Rhizobium used as biofertilizers in the agriculture. The ability of controlling plant diseases by using Rhizobium produced secondary metabolites as biocontrol agent is the current open area in the agriculture research. The nodules inhabited Rhizobium strains were selected for the production of secondary metabolites and the ability of controlling Fusarium was evaluated preliminarily by agar well diffusion assay. Four different Rhizobium were isolated, among that S1 cannot showed any inhibition, whereas S2, S3 and S4 were showed 11, 15 and 19mm of inhibition respectively.Among that S4 selected further and DNA isolated and identified using 16S rDNA gene sequencing. The sequences were submitted in genbank and got accession number MH165175. This organism was found to be Bradyrhizobium japonicum and mass cultured for compound extraction using organic solvents. The extracted secondary metabolite were purified using different chromatography techniques. The purified fractions were analyzed for the biocontrol of Fusarium sp., isolated from infected cowpea and results showed fraction 4showed 21mm zone of inhibition. Further the selected fractions were analytically characterized to know the compounds present. Finally the purified compounds were evaluated for its biocontrol behavior against Fusaium sp., and plant growth promotion in in vitro conditions.
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Erniyani, Kristina. "EFEKTIVITAS STRAIN BRADYRHIZOBIUM JAPONICUM YANG DIISOLASI DARI BEBERAPA LOKASI DI ENDE TERHADAP PEMBENTUKAN NODUL DAN PENAMBATAN NITROGEN PADA TANAMAN KEDELAI (GLYCINE MAX L.)." AGRICA 3, no. 2 (July 22, 2020): 138–50. http://dx.doi.org/10.37478/agr.v3i2.501.
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Bacteria Bradyrhizobium spp. From nodules on soybean plants, bind nitrogen from the air and make it freely available to plants. Amount of nitrogen fixed depends on the ability of a strain to form nodules, nodule effectiveness and environmental conditions. On land – land that had been planted with soybeans, inoculation with Bradyrizhobium bacteria are often not required. To test these lands in the district of Ende, NTT has conducted an experiment with a factor in the design of Randomized Complete with nine treatment groups. The treatment consists of (i) inoculation with the soybean crop in the ground former Ekoae (R1), (ii) inokulasi with soil former soybean plants in Ndona (R2), (iii) inoculation of soybean plants with the soil used in Flores (R3), (iv) Brady rhizobium isolates from soybean nodules in Ekoae (R4), (v) Bradyrhizobium isolates from nodules of soybean plants is in Ndona (R5), (v) Bradyrhozobium isolates from nodules of soybean plants at Flores (R6) (vii) a commercial inoculant legin (L), (viii) fertilizer nitrogen (N), and (ix) Control (K). all treatments were repeated 4 times. Land used in these experiments is the land of Ndona. The experiment was carried out since faculty, Udayana University. The highest percentage of effective nodules on the treatment Bradyrhizobium isolates from sybean nodules in Ndona (R5). Total nitrogen levels at the age of 45 HST in the highest in soybean plants that received 100 kg ha-1 urea and soybeans that have a desolate Bradyrhizobium inoculation of soybean nodules in Ndona (R). Efficiency and levels of symbiotic nitrogen fixation result obtained highest in soybean plants that received an inoculation Bradyrhizobium diisolat soybean nodules in Ndona (R5). Oven dry weight of plants that from the age of 45 HST on all isolates are equivalent to the oven-dry weight of plants at the fertilization of 100 kg ha- 1 urea. The result shoed that the land – the land of Ekoae, Ndona and Fkres have high Bradirhizobium contain bacteria. Bacteria Bradyrhizobium cp. Most numerous in the isolates from soybean nodules in Ndona (R5) the most efficient from effective nodules is 82.26% and as high as the 0.52% N fixate. These results indicate that isolates from Ndona Bradyrhizobiun veeb able to form effective nonudel on yoy beans grown in soil from Ndona. The result also indicates inoculation with a commercial inoculant was obtained not on land – land planted with soybeans used
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Moukoumi, Judicaël, Russell K. Hynes, Timothy J. Dumonceaux, Jennifer Town, and Nicolas Bélanger. "Characterization and genus identification of rhizobial symbionts from Caragana arborescens in western Canada." Canadian Journal of Microbiology 59, no. 6 (June 2013): 399–406. http://dx.doi.org/10.1139/cjm-2013-0158.
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Naturally occurring nitrogen-fixing symbionts from root nodules of caragana (Caragana arborescens) growing in central Saskatchewan were isolated following surface sterilization of caragana root nodules and squashing and spreading of the contents on yeast extract – mannitol medium. The symbiotic nature of the strains was confirmed following inoculation onto surface-sterilized C. arborescens seed in a gnotobiotic Leonard jar system. The Rhizobium isolates from C. arborescens root nodules were intermediate in generation time (g) (mean g of 5 isolates was 6.41 h) compared with the fast growers, Rhizobium leguminosarum NRG457 (g: 4.44 h), Rhizobium tropici 899 (g: 3.19 h), and Sinorhizobium meliloti BALSAC (g: 3.45 h), but they were faster than the slow-growing Bradyrhizobium japonicum USDA 110 (g: 13.86 h) and similar to Mesorhizobium amorphae (g: 7.76 h). Nitrogen derived from fixation by measuring changes in δ15N natural abundance in plant tissue confirmed the effectiveness of the strains; approximately 80% N2 from fixation. Strain identification was carried out by determining the sequences of 3 genes: 16S rRNA-encoding genes, cpn60, and recA. This analysis determined that the symbiotic partner of Canadian C. arborescens belongs to the genus Mesorhizobium and seems more related to M. loti than to previously described caragana symbionts like M. caraganae. This is the first report of Mesorhizobium sp. nodulating C. arborescens in western Canada.
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Bossolani, João W., Nadia M. Poloni, Edson Lazarini, João V. T. Bettiol, João A. Fischer Filho, and Matheus M. Negrisoli. "Development of RR soybean in function of glyphosate doses and Bradyrhizobium inoculation." Revista Brasileira de Engenharia Agrícola e Ambiental 22, no. 12 (December 2018): 854–58. http://dx.doi.org/10.1590/1807-1929/agriambi.v22n12p854-858.
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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.
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Cantera, Jose Jason L., Hiroko Kawasaki, and Tatsuji Seki. "The nitrogen-fixing gene (nifH) of Rhodopseudomonas palustris: a case of lateral gene transfer?" Microbiology 150, no. 7 (July 1, 2004): 2237–46. http://dx.doi.org/10.1099/mic.0.26940-0.
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Nitrogen fixation is catalysed by some photosynthetic bacteria. This paper presents a phylogenetic comparison of a nitrogen fixation gene (nifH) with the aim of elucidating the processes underlying the evolutionary history of Rhodopseudomonas palustris. In the NifH phylogeny, strains of Rps. palustris were placed in close association with Rhodobacter spp. and other phototrophic purple non-sulfur bacteria belonging to the α-Proteobacteria, separated from its close relatives Bradyrhizobium japonicum and the phototrophic rhizobia (Bradyrhizobium spp. IRBG 2, IRBG 228, IRBG 230 and BTAi 1) as deduced from the 16S rRNA phylogeny. The close association of the strains of Rps. palustris with those of Rhodobacter and Rhodovulum, as well as Rhodospirillum rubrum, was supported by the mol% G+C of their nifH gene and by the signature sequences found in the sequence alignment. In contrast, comparison of a number of informational and operational genes common to Rps. palustris CGA009, B. japonicum USDA 110 and Rhodobacter sphaeroides 2.4.1 suggested that the genome of Rps. palustris is more related to that of B. japonicum than to the Rba. sphaeroides genome. These results strongly suggest that the nifH of Rps. palustris is highly related to those of the phototrophic purple non-sulfur bacteria included in this study, and might have come from an ancestral gene common to these phototrophic species through lateral gene transfer. Although this finding complicates the use of nifH to infer the phylogenetic relationships among the phototrophic bacteria in molecular diversity studies, it establishes a framework to resolve the origins and diversification of nitrogen fixation among the phototrophic bacteria in the α-Proteobacteria.
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Soberón, Mario, Oswaldo López, Claudia Morera, Maria de Lourdes Girard, Maria Luisa Tabche, and Juan Miranda. "Enhanced Nitrogen Fixation in a Rhizobium etli ntrC Mutant That Overproduces the Bradyrhizobium japonicum Symbiotic Terminal Oxidasecbb3." Applied and Environmental Microbiology 65, no. 5 (May 1, 1999): 2015–19. http://dx.doi.org/10.1128/aem.65.5.2015-2019.1999.
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ABSTRACT The ntrC gene codes for a transcriptional activator protein that modulates gene expression in response to nitrogen. The cytochrome production pattern of a Rhizobium etli ntrCmutant (CFN2012) was studied. CO difference spectral analysis of membranes showed that CFN2012 produced a terminal oxidase similar to the symbiotic terminal oxidase of bacteroids in free-living cells under aerobic conditions, with a characteristic trough at 553 nm. CFN2012 produced two c-type cytochromes with molecular masses of 27 and 32 kDa, in contrast with the wild-type strain, which produced only a 32-kDa c-type cytochrome. The expression levels of theR. etli fixNOQP operon, which codes for terminal oxidasecbb 3, were not affected by the ntrCmutation. However, the production levels of the two c-type cytochromes (27 and 32 kDa) were enhanced at least eightfold when theBradyrhizobium japonicum fixNOQP operon was expressed in CFN2012 from the nptII promoter (pMSfixc), suggesting that these proteins are subunits FixO (27 kDa) and FixP (32 kDa) of cbb 3 and that CFN2012/pMSfixc overproduced this terminal oxidase. CFN2012/pMSfixc showed a significant increase in its symbiotic performance as judged by the determination of nitrogenase activities of plants inoculated with this strain, suggesting that the overproduction of cbb 3 terminal oxidase correlates with an enhancement in symbiotic nitrogen fixation.
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VOROBEY, Nadiya, Kateryna KUKOL, Petro PUKHTAIEVYCH, and Tetyana KOTS. "Symbiotic and physiological indicators of soybean inoculated of Bradyrhizobium japonicum single-strain in 7 days before sowing." Acta agriculturae Slovenica 118, no. 2 (July 8, 2022): 1. http://dx.doi.org/10.14720/aas.2022.118.2.1867.
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<p class="042abstractstekst">Results of investigation of soybean of the Almaz variety in inoculation with preparations based on nodule bacteria <em>Bradyrhizobium japonicum</em> (Kirchner, 1896), Jordan, 1982 B78, B157, D37, D87 are presented. Different periods of the soybean seeds inoculation were used - on the sowing day (control) and in 7 days before sowing (experimental variants). The differences between control and experimental plants in the formation and functioning of the symbiotic apparatus and its functional activity, depending on the period between from seed inoculation to sowing were analysed. It was determined that the number of root nodules in the control plants was higher. The mass of nodules at the stage of 3 true leaves exceeded the control by 1.5–2.0 times in plants inoculated in 7 days before sowing, and the intensity of nitrogen fixation by 1.7–6.6 times. At the budding-beginning of flowering stage, the mass and intensity of N<sub>2</sub> fixation by the nodules of control plants increased. As a result, the difference between the nitrogen fixing activity of control and experimental plants decreased significantly. Stimulating effect on aboveground mass of <em>Bradyrhizobium japonicum</em> strains with increased nitrogen fixing activity was noted. Optimal conditions for the formation and functioning of bean-rhizobial symbiosis were provided at the use of both of these terms of soybean inoculation. This reveals the possibility of effective application of early inoculation of soybean seeds with preparations based on nodule bacteria <em>Bradyrhizobium japonicum</em> active strains.</p>
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Bono, José Antonio Maior, Talles Edmundo de Assis, and André Luiz Araújo Martinelli. "Adubação Suplementar de Nitrogênio na Soja Via Solo e Foliar na Fase Reprodutiva." UNICIÊNCIAS 24, no. 1 (February 11, 2021): 24–29. http://dx.doi.org/10.17921/1415-5141.2020v24n1p24-29.
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A planta de soja tem a associação simbiôntica com micro-organismos que têm a capacidade de fixar nitrogênio (N) e liberá-lo para as plantas. Nas cultivares de soja de alto potencial produtivo, a demanda por N estaria sendo atendida através da fixação biológica de nutrientes (FBN) ou haveria a necessidade de complementação deste nutriente para a cultura. Este trabalho teve como objetivo verificar a resposta da cultivar de soja Desafio inoculada com bactérias Bradyrhizobium japonicum e Bradyrhizobium elkanii, e com adubação nitrogenada suplementar na fase reprodutiva, via solo e via foliar. Os tratamentos constituíram da testemunha (sem aplicação de N), 30 e 60 kg de N ha-1 via solo e solução a 2% de N aplicados nas fases R1 e R5.3. O delineamento foi de blocos casualizados com quatro repetições e as sementes foram inoculadas com bactérias das espécies Bradyrhizobium japonicum e Bradyrhizobium elkanii (estirpes Semia 587 e Semia 5019). A aplicação tardia de N em R1 e em R5.3 proporcionou aumento na produtividade de grãos de 478,6 kg ha-1 e 472,8 kg ha-1, respectivamente. A aplicação via solo de N em R1 apresenta melhor índice de colheita, quando comparada com a R5.3. A aplicação tardia de solução de 2% de N, via foliar, não proporciona aumento na produtividade da cultura da soja.
Palavras-chave: Glycine max. Produtividade. Fixação Biológica. Adubação Nitrogenada.
Abstract
The soybean plant has the symbiotic association with microorganisms that has the ability to fix nitrogen (N) and release it to the plants. Soybean cultivars with high productive potential, N demand would be met through biological nutrient fixation (BNF) or there would be a need to complement this nutrient for the crop. The objective of this work was to verify the response of soybean inoculated with bacteria of the genus Rhizobium and Bradyrhizobium, the supplementary nitrogen fertilization in the reproductive phase, soil and leaf pathway. The treatments consisted of control (without application of N), 30 and 60 kg of N ha-1 via soil and 2 % N solution applied in phases R1 and R5.3. The design was randomized blocks with 4 replications and the seeds were inoculated with bacteria of the species Bradyrhizobium japonicum and Bradyrhizobium elkanii (strains Semia 587 and Semia 5019). The late application of N in R1 and R5.3 increased grain yield of 478.6 kg ha-1 and 472.8 kg ha-1, respectively. The application, via soil, of N in R1 presents a better harvest index, when compared to R5.3. The late application of 2% N solution, via leaf, did not increase the soybean crop yield
Keywords: Glycine max. Productivity. Biological Fixation. Nitrogen Fertilization
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Baker, Michael E. "Similarities between legume–rhizobium communication and steroid-mediated intercellular communication in vertebrates." Canadian Journal of Microbiology 38, no. 6 (June 1, 1992): 541–47. http://dx.doi.org/10.1139/m92-089.
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Regulation of the actions of flavonoids and Nod factors in legume–rhizobia communication has several interesting similarities with that of steroid-mediated actions in vertebrates. Oxidation or reduction of flavonoids and Nod factors modifies their biological activity just as, for example, oxidation of an alcohol at C11 on hydrocortisone regulates its biological activity. Second, some flavonoids are anti-inducers, functioning like steroid antagonists to negate the actions of inducer flavonoids. Amino acid sequence analyses show that human 17β-hydroxysteroid dehydrogenase, which catalyzes the interconversion of the alcohol and ketone at C17 on estrogens and androgens, and rat 11β-hydroxysteroid dehydrogenase, which catalyzes the interconversion of the alcohol and ketone at C11 of glucocorticoids, and Rhizobium meliloti NodG and Bradyrhizobium japonicum. FixR are derived from a common ancestor. Just as steroid-metabolizing enzymes can regulate steroid-mediated gene transcription, enzymes that modify substituents on flavonoids and Nod factors may have a similar role in regulating signalling between legumes and rhizobia. The enzymes that modify flavonoids and Nod factors have not yet been identified. However, NodG and FixR are two likely candidates to have this role in regulating legume–rhizobia signalling. Key words: NodG function, FixR function, steroid–flavonoid similarities, steroids and nitrogen fixation.
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Kots, S. Ya, S. M. Malychenko, P. M. Mamenko, and G. M. Drozdenko. "PERSPECTIVE USE OF TN5-MUTANTS OF RHIZOBIA IN PREPARATION OF BACTERIAL FERTILIZERS." Agriciltural microbiology 8 (May 5, 2009): 32–39. http://dx.doi.org/10.35868/1997-3004.8.32-39.
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By using strain of Escherichia coli with build-in plasmid pSUP2021::Tn5 the transposon mutagenesis of Bradyrhizobium japonicum (strains 646, 614a and 71t) was performed. The highest formation frequency of kanamycinresistant mutants was 10-6 (B. japonicum 646). Among the 1500 mutants obtained, the best were selected by the “virulence”, “nitrogen fixation activity” and “symbiosis efficiency” criteria. In spite of different symbiotic characteristics of the selected Tn-5 mutants no considerable differences in their protein composition were determined. The authors made conclusion on the possibility of use of transposon mutagenesis in order to obtain the new forms of slowgrowing bacteria.
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Birkenhead, K., S. S. Manian, and F. O'Gara. "Dicarboxylic acid transport in Bradyrhizobium japonicum: use of Rhizobium meliloti dct gene(s) to enhance nitrogen fixation." Journal of Bacteriology 170, no. 1 (1988): 184–89. http://dx.doi.org/10.1128/jb.170.1.184-189.1988.
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Krugova, E. D., N. M. Mandrovska, and S. Ya Kots. "THE INFLUENCE OF SYNTHETIC POLYSACCHARIDE ON BOTH EFFICIENCY OF SYMBIOSIS AND PEROXIDASE AND CATALASE ACTIVENESS OF PEA AND SOYA BEANS." Agriciltural microbiology 4 (February 7, 2007): 62–73. http://dx.doi.org/10.35868/1997-3004.4.62-73.
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The influence of synthetic polysaccharide MOD-19 on the effic¬iency of nitrogen fixation ofpea and soya plants as well as on ferment activity of the antioxidative defense system - peroxidase and catalase was investigated. It has been shown that the metabolic process intensifying is ob¬served in pea and soya plants grown from the seeds, wich had been tilled before sowing by nodule bacterium (pea - Rhizobium leguminosarum bv. viciae 263b and soya beans - Bradyrhizobium japonicum 634b) and by nonspecific for these bean cultures polysaccharide MOD-19. This has been proved by morphological and functional haracteristics of these systems, the increasing of plant biomass and nodules quantiity on the roots. The active functioning period of nodules is elongating at the expense of secondary nodules formation on the side roots and their nitrogen activity increased. Rising of the oxidative ferment activity level for peroxydase and catalase was found in these plants.
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King, Natalie D., David Hojnacki, and Mark R. O'Brian. "The Bradyrhizobium japonicum Proline Biosynthesis Gene proC Is Essential for Symbiosis." Applied and Environmental Microbiology 66, no. 12 (December 1, 2000): 5469–71. http://dx.doi.org/10.1128/aem.66.12.5469-5471.2000.
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ABSTRACT Plant host-derived proline is proposed to serve as an energy source for rhizobia in the rhizosphere and in symbiotic root nodules. TheBradyrhizobium japonicum proC gene was isolated, and aproC mutant strain that behaved as a strict proline auxotroph in culture was constructed. The proC strain elicited undeveloped nodules on soybeans that lacked nitrogen fixation activity and plant hemoglobin. We conclude that the proCgene is essential for symbiosis and suggest that the mutant does not obtain an exogenous supply of proline in association with soybeans sufficient to satisfy its auxotrophy.
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Safronova, Vera I., Andrey A. Belimov, Anna L. Sazanova, Elizaveta R. Chirak, Alla V. Verkhozina, Irina G. Kuznetsova, Evgeny E. Andronov, Jan V. Puhalsky, and Igor A. Tikhonovich. "Taxonomically Different Co-Microsymbionts of a Relict Legume, Oxytropis popoviana, Have Complementary Sets of Symbiotic Genes and Together Increase the Efficiency of Plant Nodulation." Molecular Plant-Microbe Interactions® 31, no. 8 (August 2018): 833–41. http://dx.doi.org/10.1094/mpmi-01-18-0011-r.
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Ten rhizobial strains were isolated from root nodules of a relict legume Oxytropis popoviana Peschkova. For identification of the isolates, sequencing of rrs, the internal transcribed spacer region, and housekeeping genes recA, glnII, and rpoB was used. Nine fast-growing isolates were Mesorhizobium-related; eight strains were identified as M. japonicum and one isolate belonged to M. kowhaii. The only slow-growing isolate was identified as a Bradyrhizobium sp. Two strains, M. japonicum Opo-242 and Bradyrhizobium sp. strain Opo-243, were isolated from the same nodule. Symbiotic genes of these isolates were searched throughout the whole-genome sequences. The common nodABC genes and other symbiotic genes required for plant nodulation and nitrogen fixation were present in the isolate Opo-242. Strain Opo-243 did not contain the principal nod, nif, and fix genes; however, five genes (nodP, nodQ, nifL, nolK, and noeL) affecting the specificity of plant-rhizobia interactions but absent in isolate Opo-242 were detected. Strain Opo-243 could not induce nodules but significantly accelerated the root nodule formation after coinoculation with isolate Opo-242. Thus, we demonstrated that taxonomically different strains of the archaic symbiotic system can be co-microsymbionts infecting the same nodule and promoting the nodulation process due to complementary sets of symbiotic genes.
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Calheiros, Altanys Silva, Mario de Andrade Lira Junior, Débora Magalhães Soares, and Márcia do Vale Barreto Figueiredo. "Symbiotic capability of calopo rhizobia from an agrisoil with different crops in Pernambuco." Revista Brasileira de Ciência do Solo 37, no. 4 (August 2013): 869–76. http://dx.doi.org/10.1590/s0100-06832013000400005.
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Biological nitrogen fixation by rhizobium-legume symbiosis represents one of the most important nitrogen sources for plants and depends strongly on the symbiotic efficiency of the rhizobium strain. This study evaluated the symbiotic capacity of rhizobial isolates from calopo (CALOPOGONIUM MUCUNOIDES) taken from an agrisoil under BRACHIARIA DECUMBENS pasture, sabiá (MIMOSA CAESALPINIIFOLIA) plantations and Atlantic Forest areas of the Dry Forest Zone of Pernambuco. A total of 1,575 isolates were obtained from 398 groups. A single random isolate of each group was authenticated, in randomized blocks with two replications. Each plant was inoculated with 1 mL of a bacterial broth, containing an estimated population of 10(8) rhizobial cells mL-1. Forty-five days after inoculation, the plants were harvested, separated into shoots, roots and nodules, oven-dried to constant mass, and weighed. Next, the symbiotic capability was tested with 1.5 kg of an autoclaved sand:vermiculite (1:1) mixture in polyethylene bags. The treatments consisted of 122 authenticated isolates, selected based on the shoot dry matter, five uninoculated controls (treated with 0, 50, 100, 150, or 200 kg ha-1 N) and a control inoculated with SEMIA 6152 (=BR1602), a strain of BRADYRHIZOBIUM JAPONICUM The test was performed as described above. The shoot dry matter of the plants inoculated with the most effective isolates did not differ from that of plants treated with 150 kg ha-1 N. Shoot dry matter was positively correlated with all other variables. The proportion of effective isolates was highest among isolates from SABIÁ forests. There was great variation in nodule dry weight, as well as in N contents and total N.
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Báscones, Elena, Juan Imperial, Tomás Ruiz-Argüeso, and Jose Manuel Palacios. "Generation of New Hydrogen-RecyclingRhizobiaceae Strains by Introduction of a Novelhup Minitransposon." Applied and Environmental Microbiology 66, no. 10 (October 1, 2000): 4292–99. http://dx.doi.org/10.1128/aem.66.10.4292-4299.2000.
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ABSTRACT Hydrogen evolution by nitrogenase is a source of inefficiency for the nitrogen fixation process by the Rhizobium-legume symbiosis. To develop a strategy to generate rhizobial strains with H2-recycling ability, we have constructed a Tn5derivative minitransposon (TnHB100) that contains the ca. 18-kb H2 uptake (hup) gene cluster fromRhizobium leguminosarum bv. viciae UPM791. Bacteroids from TnHB100-containing strains of R. leguminosarum bv. viciae PRE, Bradyrhizobium japonicum, R. etli, and Mesorhizobium loti expressed high levels of hydrogenase activity that resulted in full recycling of the hydrogen evolved by nitrogenase in nodules. Efficient processing of the hydrogenase large subunit (HupL) in these strains was shown by immunoblot analysis of bacteroid extracts. In contrast, Sinorhizobium meliloti,M. ciceri, and R. leguminosarum bv. viciae UML2 strains showed poor expression of the hup system that resulted in H2-evolving nodules. For the latter group of strains, no immunoreactive material was detected in bacteroid extracts using anti-HupL antiserum, suggesting a low level of transcription ofhup genes or HupL instability. A general procedure for the characterization of the minitransposon insertion site and removal of antibiotic resistance gene included in TnHB100 has been developed and used to generate engineered strains suitable for field release.
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Kots, S. Y., T. P. Mamenko, and A. V. Pavlyshche. "Activity of nitrogen fixation and antioxidant enzymes in symbiotic systems Glycine max – Bradyrhizobium japonicum for complex treatment with lectin and fungicides." Regulatory Mechanisms in Biosystems 9, no. 2 (March 29, 2018): 148–55. http://dx.doi.org/10.15421/021822.
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The dynamics of the nitrogen fixation activity of the root nodules, the growth of the vegetative mass of plants and the change in the activity of antioxidant enzymes (superoxide dismutase, ascorbate and guaiacol peroxidase) in different soybean organs for treatment of seeds by rhizobia incubated with lectin, in combination with fungicides have been studied. The objects of the study were symbiotic systems formed with the participation of soybean (Glycine max (L.) Merr.) Almaz and Bradyrhizobium japonicum (standard strain 634b) incubated with lectin. As disinfectants of soybean seeds, the following preparations with fungicidal activity were used – Maxim XL 035 PS, Fever, Standak Top according to one rate of active substance consumption of each preparation specified by the manufacturer. One part of the seeds treated with fungicides was inoculated with pure culture of suspension of rhizobia for one hour (titre of suspension concentration was 108 cells/ml). Another part of the seeds treated with fungicides was inoculated with rhizobia suspension, which was previously incubated with a solution of commercial lectin soybean at a concentration of 100 μg/ml. The research was conducted in strictly controlled conditions of a model vegetative experiment using microbiological, physiological, biochemical methods, gas chromatography, spectrophotometry. It was found that processing of soybean seeds with fungicides (Fever and Maxim XL) together with rhizobium inoculation contributed to the preservation of the nitrogen fixation activity of the root nodules and the growth of vegetative mass of plants. Under these conditions, the intensification of the activity of superoxide dismutase and ascorbate peroxidase was observed, as well as inhibition of the activity of guaiacol peroxidase in soybean root nodules in the phase of three true leaves and increased activity of all investigated enzymes in the phase of mass flowering. It has been established that the use of complex treatment of seeds by soybean rhizobia incubated with lectin and fungicides leads to an increase in the activity of superoxide dismutase and guaiacol peroxidase in root nodules in the phase of three true leaves and the growth of the activity of ascorbate peroxidase in the phase of mass flowering. At the same time, the inhibition of the growth of vegetative mass of plants and their symbiotic properties occurred, as evidenced by the decrease in the nitrogen fixation activity of the root nodules for the joint treatment of seeds with fungicides and lectin. A specific reaction of investigated enzymes in the roots and leaves of soybean was shown, which was more pronounced in the phase of three true leaves, indicating the development of a typical antioxidant reaction to a complex treatment, as a kind of stress that is leveled to the phase of mass flowering. The degree of reaction of antioxidant enzymes in the studied symbiotic systems Glycine max – Bradyrhizobium japonicum depends on the nature of the active substance fungicides and the manifestation of their joint effect in a complex with rhizobia incubated with lectin.
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Göttfert, Michael, Sandra Röthlisberger, Christoph Kündig, Christoph Beck, Roger Marty, and Hauke Hennecke. "Potential Symbiosis-Specific Genes Uncovered by Sequencing a 410-Kilobase DNA Region of the Bradyrhizobium japonicum Chromosome." Journal of Bacteriology 183, no. 4 (February 15, 2001): 1405–12. http://dx.doi.org/10.1128/jb.183.4.1405-1412.2001.
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ABSTRACT The physical and genetic map of the Bradyrhizobium japonicum chromosome revealed that nitrogen fixation and nodulation genes are clustered. Because of the complex interactions between the bacterium and the plant, we expected this chromosomal sector to contain additional genes that are involved in the maintenance of an efficient symbiosis. Therefore, we determined the nucleotide sequence of a 410-kb region. The overall G+C nucleotide content was 59.1%. Using a minimum gene length of 150 nucleotides, 388 open reading frames (ORFs) were selected as coding regions. Thirty-five percent of the predicted proteins showed similarity to proteins of rhizobia. Sixteen percent were similar only to proteins of other bacteria. No database match was found for 29%. Repetitive DNA sequence-derived ORFs accounted for the rest. The sequenced region contained all nitrogen fixation genes and, apart from nodM, all nodulation genes that were known to exist in B. japonicum. We found several genes that seem to encode transport systems for ferric citrate, molybdate, or carbon sources. Some of them are preceded by −24/−12 promoter elements. A number of putative outer membrane proteins and cell wall-modifying enzymes as well as a type III secretion system might be involved in the interaction with the host.
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Menna, Pâmela, and Mariangela Hungria. "Phylogeny of nodulation and nitrogen-fixation genes in Bradyrhizobium: supporting evidence for the theory of monophyletic origin, and spread and maintenance by both horizontal and vertical transfer." International Journal of Systematic and Evolutionary Microbiology 61, no. 12 (December 1, 2011): 3052–67. http://dx.doi.org/10.1099/ijs.0.028803-0.
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Bacteria belonging to the genus Bradyrhizobium are capable of establishing symbiotic relationships with a broad range of plants belonging to the three subfamilies of the family Leguminosae ( = Fabaceae), with the formation of specialized structures on the roots called nodules, where fixation of atmospheric nitrogen takes place. Symbiosis is under the control of finely tuned expression of common and host-specific nodulation genes and also of genes related to the assembly and activity of the nitrogenase, which, in Bradyrhizobium strains investigated so far, are clustered in a symbiotic island. Information about the diversity of these genes is essential to improve our current poor understanding of their origin, spread and maintenance and, in this study, we provide information on 40 Bradyrhizobium strains, mostly of tropical origin. For the nodulation trait, common (nodA), Bradyrhizobium-specific (nodY/K) and host-specific (nodZ) nodulation genes were studied, whereas for fixation ability, the diversity of nifH was investigated. In general, clustering of strains in all nod and nifH trees was similar and the Bradyrhizobium group could be clearly separated from other rhizobial genera. However, the congruence of nod and nif genes with ribosomal and housekeeping genes was low. nodA and nodY/K were not detected in three strains by amplification or hybridization with probes using Bradyrhizobium japonicum and Bradyrhizobium elkanii type strains, indicating the high diversity of these genes or that strains other than photosynthetic Bradyrhizobium must have alternative mechanisms to initiate the process of nodulation. For a large group of strains, the high diversity of nod genes (with an emphasis on nodZ), the low relationship between nod genes and the host legume, and some evidence of horizontal gene transfer might indicate strategies to increase host range. On the other hand, in a group of five symbionts of Acacia mearnsii, the high congruence between nod and ribosomal/housekeeping genes, in addition to shorter nodY/K sequences and the absence of nodZ, highlights a co-evolution process. Additionally, in a group of B. japonicum strains that were symbionts of soybean, vertical transfer seemed to represent the main genetic event. In conclusion, clustering of nodA and nifH gives additional support to the theory of monophyletic origin of the symbiotic genes in Bradyrhizobium and, in addition to the analysis of nodY/K and nodZ, indicates spread and maintenance of nod and nif genes through both vertical and horizontal transmission, apparently with the dominance of one or other of these events in some groups of strains.
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Kober, Marcia de Vargas, Enilson Luiz Saccol de Sá, João Ruy Jardim Freire, and Adriana Giongo. "Characterization of variants of Bradyrhizobium elkanii and B. japonicum and symbiotic behaviour in soybeans." Ciência Rural 34, no. 5 (October 2004): 1459–64. http://dx.doi.org/10.1590/s0103-84782004000500020.
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Variation in rhizobia strains isn’t a desirable fact based mainly on the possibility of unexpected results on legume inoculation. In this work, we studied the variability on phenotypic characteristics and genetic stability of rhizobia strains recommended for soybean inoculation. Variants with stable colony morphology were obtained from Bradyrhizobium japonicum strain SEMIA 5080 and from B. elkanii SEMIA 5019. Variants from SEMIA 587 obtained by another author were also used. The variants differed on colony characteristics, nodulation capacity, nitrogen fixation efficiency and competitive ability for nodule formation in two soybean varieties (Jacui 7 and IAS 5). Symbiotic behavior varied according to plant variety. Only the variants 5019 G and 5019 P differed on the isoenzymatic profile. There were differences in antibiotic resistance between variants from two strains. Correlation between symbiotic characteristics and colony morphology or antibiotic resistance wasn’t conclusive. The results indicate that the variability in rhizobia strains might be an important factor to be considered in strain selection and preservation of cultures for inoculant production.
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Mamenko, T. P., S. Ya Kots, L. M. Mykhalkiv, and Yu A. Homenko. "Phenylalanine Ammonia-Lyase Enzyme Activity in the Symbiotic System Glycine max – Bradyrhizobium japonicum by Seed Inoculation Different in Activity and Virulation Strain and Treatment with Fungicides." Mikrobiolohichnyi Zhurnal 83, no. 4 (August 17, 2021): 63–73. http://dx.doi.org/10.15407/microbiolj83.04.063.
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Phenylalanine ammonia-lyase (PAL) is a key enzyme of the phenylpropanoid pathway and provides precursors for the synthesis of many secondary metabolites, which are necessary for the development and protection of plants from external factors of various natures, in particular plays an important role in the formation and development of their symbiosis with microorganisms. Aim. To study the activity of PAL in soybean plants in the early stages of legume-rhizobial symbiosis under the influence of seed inoculation with Bradyrhizobium japonicum strains with different symbiotic properties on the background of fungicide treatment. Methods. Microbiology (bacterial culture growing, seeds inoculation), physiological (pot experiment), biochemical (determining the PAL enzyme activity). Results. Inoculation of soybean seeds with active virulent rhizobia induces a significant decrease in PAL activity in the roots at the primordial leaf stage and a significant increase in its activity level at the first true leaf stage, compared to inactive symbiosis. At the stage of third true leaf, the activity of PAL increased more significantly in soybean root nodules formed by inactive rhizobia, compared to active symbiosis. However, at the stage of third true leaves, the activity of PAL in soybean root nodules formed by inactive rhizobia increased significantly compared to active symbiosis. The use of fungicides for pre-sowing treatment of soybean seeds induces changes in the level of PAL activity in roots and nodules, which do not affect the overall dynamics of enzyme activity in different effective symbiotic systems Glycine max - Bradyrhizobium japonicum. Conclusions. The activity of PAL in the roots and especially in the root nodules of soybeans in the early stage of plant development in the case of fungicides using and bacterization is primarily due to the action of the inoculation factor, and is determined by the symbiotic properties of rhizobia strains, in particular, their virulence and nitrogen fixation activity.
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Sudtachat, Nirinya, Naofumi Ito, Manabu Itakura, Sachiko Masuda, Shima Eda, Hisayuki Mitsui, Yasuyuki Kawaharada, and Kiwamu Minamisawa. "Aerobic Vanillate Degradation and C1 Compound Metabolism in Bradyrhizobium japonicum." Applied and Environmental Microbiology 75, no. 15 (June 5, 2009): 5012–17. http://dx.doi.org/10.1128/aem.00755-09.
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ABSTRACT Bradyrhizobium japonicum, a symbiotic nitrogen-fixing soil bacterium, has multiple gene copies for aromatic degradation on the genome and is able to use low concentrations of vanillate, a methoxylated lignin monomer, as an energy source. A transcriptome analysis indicated that one set of vanA1B, pcaG1H1, and genes for C1 compound catabolism was upregulated in B. japonicum USDA110 cells grown in vanillate (N. Ito, M. Itakura, S. Eda, K. Saeki, H. Oomori, T. Yokoyama, T. Kaneko, S. Tabata, T. Ohwada, S. Tajima, T. Uchiumi, E. Masai, M. Tsuda, H. Mitsui, and K. Minamisawa, Microbes Environ. 21:240-250, 2006). To examine the functions of these genes in vanillate degradation, we tested cell growth and substrate consumption in vanA1B, pcaG1H1, and mxaF mutants of USDA110. The vanA1B and pcaG1H1 mutants were unable to grow in minimal media containing 1 mM vanillate and protocatechuate, respectively, although wild-type USDA110 was able to grow in both media, indicating that the upregulated copies of vanA1B and pcaG1H1 are exclusively responsible for vanillate degradation. Mutating mxaF eliminated expression of gfa and flhA, which contribute to glutathione-dependent C1 metabolism. The mxaF mutant had markedly lower cell growth in medium containing vanillate than the wild-type strain. In the presence of protocatechuate, there was no difference in cell growth between the mxaF mutant and the wild-type strain. These results suggest that the C1 pathway genes are required for efficient vanillate catabolism. In addition, wild-type USDA110 oxidized methanol, whereas the mxaF mutant did not, suggesting that the metabolic capability of the C1 pathway in B. japonicum extends to methanol oxidation. The mxaF mutant showed normal nodulation and N2 fixation phenotypes with soybeans, which was not similar to symbiotic phenotypes of methylotrophic rhizobia.
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Ferrey, M. L., P. H. Graham, and M. P. Russelle. "Nodulation efficiency of Bradyrhizobium japonicum strains with genotypes of soybean varying in the ability to restrict nodulation." Canadian Journal of Microbiology 40, no. 6 (June 1, 1994): 456–60. http://dx.doi.org/10.1139/m94-074.
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Competition from existing soil rhizobia has limited the benefits from nitrogen fixation for soybean grown in the American Midwest. A strategy being considered to overcome this problem is the use of varieties that are restricted in nodulation with soil strains, but nodulate normally with inoculant bradyrhizobia. In this study we examine the efficiency in nodulation of strains of Bradyrhizobium japonicum that have been reported as restricted in nodulation with specific genotypes of soybean, using a root-tip marking procedure in growth pouches. When B. japonicum USDA110 was applied to the soybean cultivars Hardee and Fiskeby V at the rate of 3.50 × 104 cells/pouch, more than 75% of the plants were nodulated above the root-tip mark, and average uppermost nodule position was above the root-tip mark. By contrast, when this strain was applied in similar concentration to the soybean cultivar Peking, few plants developed nodules above the root-tip mark, and the average position of the uppermost taproot nodule was nearly 30 mm below this mark. Nodulation was improved at higher rates of inoculation, but even when 3.50 × 106 cells were applied to each pouch, less than 50% of the plants were nodulated above the root-tip mark. Bradyrhizobium japonicum strain CB1809 (=USDA136) was also efficient in nodulation with cv. Fiskeby V, but with cv. Hardee, less than 65% of plants were nodulated above the root-tip mark, irrespective of inoculation rate. Because restriction of nodulation with the strains initially tested was not absolute, we examined the patterns of nodulation obtained following the inoculation of two restriction hosts, Peking and PI371607. In pure culture, serogroup USDA110 strains failed to induce significant taproot nodulation of cv. Peking in Leonard jars, but did induce lateral root nodulation. However, in a glasshouse experiment contrasting soil- and seed-applied inoculant, lateral-root nodulation of the restriction host PI371607 by USDA123 was not significant.Key words: Glycine max, competition, restriction, nodulation.
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Mamenko, T. P. "The reaction of soybean symbiotic apparatus to losses of water content in leaves and roots, induced by continuous action of drought." Ecology and Noospherology 30, no. 1 (March 2, 2019): 44–49. http://dx.doi.org/10.15421/031908.
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The reaction of the soybean symbiotic apparatus inoculated with Bradyrhizobium japonicum strains and Tn5 mutants, which were different in efficiency, was studied for the loss of water content in leaves and roots induced by prolonged drought, as well as the seed productivity of the formed symbiotic systems. To conduct researches were used microbiological, physiological, biochemical methods, gas chromatography and spectrophotometry. The objects of the study were selected symbiotic systems formed with the participation of soybean plants and strains B. japonicum 646 (active, virulent) and 604k (inactive, highly virulent), as well as Tn5-mutants – B1-20 (active, virulent) and 107 (low-active, virulent) obtained by the method of transposon mutagenesis in the department of symbiotic nitrogen fixation at the Institute of Plant Physiology and Genetics of the National Academy of Sciences of Ukraine. Before sowing, sterilized with 70 % ethanol and washed under running water for 1 h, the seeds were inoculated with suspensions of nodules bacteria (the titre of the suspension was 108 cells in 1 ml). The combined model drought was created during 12 days by stopping watering of plants up to 40 % of full moisture content starting from the stage of two true leaves and gradual transfer of watering to 30 % of full moisture content in the stage of three true leaves and budding - the beginning of flowering. After the stopping of drought, the moisture content of the substrate was adjusted to 60 % of full moisture content (watering recovery) into the stage of mass flowering. Control plants were inoculated by rhizobium culture, as well as plants without inoculation, which grew for optimal watering. It was investigated that in symbiotic systems formed with the participation of soybean and the active strain B. japonicum (646) and Tn5-mutant (B1-20) there was no significant reduction in the water content of plants under drought conditions and the effective work of the symbiotic apparatus was recorded, which contributed to the preservation of seed productivity. Ineffective symbiotic systems observed significant losses in water content and inhibition of the process of nodulation (strain 604k) and nitrogen fixation (Tn5-mutants 107), which was accompanied by significant losses of soybean crop yields. As a result of the research, it was concluded that in soil-climatic conditions with insufficient rainfall and frequent droughts, effective symbiotic systems should be used, which will promote the optimal functioning of the symbiotic apparatus and preserve the seed productivity of soybeans by adaptive regulation of water balance and fixation of molecular nitrogen of the atmosphere. The study of the functioning of leguminous plants in symbiosis with strains of nodule bacteria is important for finding effective symbiotic systems that are able to realize their adaptive potential for the effects of stress factors, in particular drought. Effective symbiotic relationships are the main source of nitrogen fixation in terrestrial ecosystems, which will reduce the need to enrich the soil with chemical compounds and provide additional economic and environmental advantage.
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Kots, S. Y., L. I. Rybachenko, T. P. Mamenko, K. P. Kukol, P. P. Pukhtaievych, and O. R. Rybachenko. "Influence of metal nanocarboxylates and different water supply conditions on efficiency of soybean-rhizobial symbiotic systems." Regulatory Mechanisms in Biosystems 12, no. 3 (November 8, 2021): 383–90. http://dx.doi.org/10.15421/022152.
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Insufficient water supply is one of the main factors that significantly reduce the activity of nitrogen fixation by legume-rhizobial symbiotic systems. That is why comprehensive research on aspects of their resistance to water stress and the search for scientifically substantiated ways to improve the existing ones and develop modern, competitive technologies of growing legumes in arid conditions are becoming especially relevant. The aim of the work was to investigate the processes of formation and functioning of soybean-rhizobial symbiotic systems developed under conditions of different water supply and influence of nanocarboxylates of cobalt, ferum, germanium, chromium, сuprum and molybdenum. The nanoparticles of specified metal nanocarboxylates were used as components of the inoculation suspension of rhizobia of Tn5 mutant B1-20 for soybean seed treatment. A model drought lasting 14 days was created by controlled irrigation. Microbiological and physiological research methods were used in the study. We determined that insufficient water supply caused a significant decrease in the nodulation potential of rhizobia and the intensity of molecular nitrogen fixation by symbiotic systems formed with the participation of soybean plants and nodule bacteria without adding these metal nanocarboxylates to the inoculation suspension. Application of most of the metal nanocarboxylates used as components of the inoculation suspension mitigated the negative impact of stress on the investigated parameters. The study revealed the stimulating effect of cobaltnanocarboxylate on the activity of molecular nitrogen fixation, which was more pronounced in the conditions of insufficient water supply. Symbiotic soybean systems formed with the participation of nodule bacteria containing germaniumcarboxylate nanoparticles were proved to be the least sensitive to the negative impact of insufficient water supply. This was indicated by high rates of nodulation and nitrogen-fixing activity compared with other studied symbiotic systems. We confirmed that the addition of chromium nanocarboxylate to the inoculation suspension of rhizobia provided the highest rates of nodulation and nitrogen-fixing activity of soybean root nodules under optimal growing conditions and, at the same time, had no noticeable positive effect under water stress. We determined that сuprum and molybdenum nanocarboxylates, as components of the inoculation suspension, regardless of the water supply level, had a less notable positive effect on the processes of nodule formation and nitrogen fixation, and in some cases even led to a decrease in the investigated values for control plants. Thus, the study demonstrated that the use of germanium, cobalt and ferum nanocarboxylates as components of the bacterial suspension helped to increase the adaptation of the formed legume-rhizobial symbiotic systems to water stress, as evidenced by the maximum indexes of nodulation and molecular nitrogen fixation in the context of insufficient water supply and recovery of their level to optimal after the stress influence had ended. Based on the results, it was concluded that inoculation of seeds by the complex bacterial preparations made on the basis of Bradyrhizobium japonicum B1-20 with a content of germanium, cobalt and ferum nanocarboxylates in the concentration of 1:1000 can become one of the important means in soybean growing technologies of increasing the nitrogen-fixing potential and resistance of plants to insufficient water supply.
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Pannecoucque, J., S. Goormachtigh, J. Ceusters, J. Debode, C. Van Waes, and J. Van Waes. "Temperature as a key factor for successful inoculation of soybean with Bradyrhizobium spp. under cool growing conditions in Belgium." Journal of Agricultural Science 156, no. 4 (May 2018): 493–503. http://dx.doi.org/10.1017/s0021859618000515.
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AbstractBacterial inoculation of soybean seeds to improve biological nitrogen fixation is a well-known practice to achieve higher seed and protein yield with reduced fertilization. The optimal inoculation strategy in temperate regions is unknown because soybeans are rarely cultivated under colder growing conditions. The aim of the present work was to determine the most suitable inoculation strategy for soybean cultivation in Belgium. Field trials were set up with four Bradyrhizobium inoculants (HiStick, Force 48, Biodoz and Optimize) at two locations over 2 years (2014–2015) and compared with a non-inoculated control treatment. In addition, HiStick was tested at three doses and Optimize at two time periods prior to sowing. Under Belgian conditions, all inoculants were effective in establishing rhizobial symbiosis, resulting in increased yield, protein content, protein yield and thousand-grain weight compared with the non-inoculated control. A single dose of HiStick was sufficient to establish symbiosis. Pre-inoculation with Optimize 2 weeks before sowing gave an intermediate performance for most parameters between the non-inoculated control treatment and inoculation with Optimize 24 h prior to sowing. Among the four products tested, Biodoz seemed the best product for inoculation under cool growing conditions. Based on the atpD gene, the bacterial strain of Biodoz showed complete similarity with Bradyrhizobium diazoefficiens, while strains of other products were identified as Bradyrhizobium japonicum. In vitro growing capacity of the Biodoz strain at 8 °C was higher compared with the other strains. Better cold adaptation of the Biodoz strain might be a possible explanation for the better performance of Biodoz in Belgium.
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Gault, RR, AL Bernardi, JA Thompson, JA Andrews, LW Banks, DM Hebb, and J. Brockwell. "Studies on alternative means of legume inoculation: appraisal of application of inoculant suspended in irrigation water (water-run inoculation)." Australian Journal of Experimental Agriculture 34, no. 3 (1994): 401. http://dx.doi.org/10.1071/ea9940401.
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Water-run inoculation is a novel means of inoculating crop legumes with species of Rhizobium or Bradyrhizobiunz. Inoculant suspended in irrigation water is delivered into the seedbed. This procedure may be apt for situations when a farmer has limited time to sow a large area and more conventional and timeconsuming means of inoculation may create a bottleneck during sowing. Field experiments with water-run inoculation of irrigated soybeans were conducted at 2 sites using furrow or flood irrigation. With furrow irrigation immediately after sowing, rhizobia-laden water had to infiltrate the soil laterally a distance of about 18 cm to reach the seed sown in single rows on hills (parallel ridges). With flood irrigation before sowing, water needed to percolate vertically only 5 cm to sowing depth. A peat inoculant of B. japonicum remained uniformly in suspension during flow of irrigation water over periods of 45 min and distances of 80 m from the point where the inoculant was introduced. With furrow irrigation on a poorly structured red brown earth, water-run inoculation applied at the normal (commercially recommended) rate did not initiate a satisfactory soybean symbiosis and was inferior to the more conventional methods, seed coat and seedbed inoculation. Rhizobial colonisation of seedling rhizospheres was limited, nodulation was sparse, and low numbers of B. japonicum re-established in the soil after harvest. Symbiosis was improved by higher rates of inoculation and was particularly enhanced in an area where the irrigation water ponded for 3-4 h allowing more time for the rhizobia-laden water to percolate the soil. With flood irrigation on a grey clay, an approximately normal rate of water-run inoculation induced an effective symbiosis especially when compared with lower rates of inoculation. Substantial populations of rhizobia developed in soybean rhizospheres, plant growth and nitrogen (N) content were enhanced, and higher levels of N2 fixation led to increased levels of N in the seed. We conclude that water-run inoculation is not an appropriate means of legume inoculation in furrow-irrigated systems on poorly structured soils but it may be a practical option for inoculation of crop legumes grown under flood irrigation.
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Mamenko, T. P., S. Y. Kots, and Y. O. Khomenko. "The intensity of ethylene release by soybean plants under the influence of fungicides in the early stages of legume-rhizobial symbiosis." Regulatory Mechanisms in Biosystems 11, no. 1 (February 22, 2020): 98–104. http://dx.doi.org/10.15421/022014.
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The effect of pre-sowing treatment of soybean seeds with fungicides on the intensity of ethylene release, the processes of nodulation and nitrogen fixation in different symbiotic systems in the early stages of ontogenesis were investigated. The objects of the study were selected symbiotic systems formed with the participation of soybean (Glycine max (L.) Merr.) Diamond variety, strains Bradyrhizobium japonicum 634b (active, virulent) and 604k (inactive, highly virulent) and fungicides Maxim XL 035 PS (fludioxonil, 25 g/L, metalaxyl, 10 g/L), and Standak Top (fipronil, 250 g/L, thiophanate methyl, 225 g/L, piraclostrobin, 25 g/L). Before sowing, the seeds of soybean were treated with solutions of fungicides, calculated on the basis of one rate of expenditure of the active substance of each preparation indicated by the producer per ton of seed. One part of the seeds treated with fungicides was inoculated with rhizobium culture for 1 h (the titre of bacteria was 107 cells/mL). To conduct the research we used microbiological, physiological, biochemical methods, gas chromatography and spectrophotometry. It is found that, regardless of the effectiveness of soybean rhizobial symbiosis, the highest level of ethylene release by plants was observed in the stages of primordial leaf and first true leaf. This is due to the initial processes of nodulation – the laying of nodule primordia and the active formation of nodules on the roots of soybeans. The results show that with the participation of fungicides in different symbiotic systems, there are characteristic changes in phytohormone synthesis in the primordial leaf stage, when the nodule primordia are planted on the root system of plants. In particular, in the ineffective symbiotic system, the intensity of phytohormone release decreases, while in the effective symbiotic system it increases. At the same time, a decrease in the number of nodules on soybean roots inoculated with an inactive highly virulent rhizobia 604k strain due to the action of fungicides and an increase in their number in variants with co-treatment of fungicides and active virulent strain 634b into the stage of the second true leaf were revealed. It was shown that despite a decrease in the mass of root nodules, there is an increase in their nitrogen-fixing activity in an effective symbiotic system with the participation of fungicides in the stage of the second true leaf. The highest intensity of ethylene release in both symbiotic systems was recorded in the stage of the first true leaf, which decreased in the stage of the second true leaf and was independent of the nature of the action of the active substances of fungicides. The obtained data prove that the action of fungicides changes the synthesis of ethylene by soybean plants, as well as the processes of nodulation and nitrogen fixation, which depend on the efficiency of the formed soybean-rhizobial systems and their ability to realize their symbiotic potential under appropriate growing conditions.
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Kots, S. Y., L. I. Rybachenko, A. V. Khrapova, K. P. Kukol, O. R. Rybachenko, and Y. O. Кhomenko. "Composition of pigment complex in leaves of soybean plants, inoculated by Bradyrhizobium japonicum, subject to metal nanocarboxylates and various-levels of water supply." Biosystems Diversity 30, no. 1 (February 2, 2022): 80–87. http://dx.doi.org/10.15421/012208.
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A distinctive feature of legumes is the ability to combine two most important processes: photosynthesis and nitrogen fixation. However, the course of those processes, and therefore seed potential of those crops depend on a number of biotic and abiotic factors, the commonest being drought. Therefore, interest in physical-biochemical resistance of the plant organism to abiotic stress factors is increasing, as well as search for optimum ways to increase its adaptability. Success of adaptation of a plant’s organism to unfavourable environmental factors is known to largely depend on optimal functioning of assimilative apparatus. Some indicators of the condition of the apparatus are the content and ratio of photosynthesis pigments. Therefore, we aimed at determining the reaction of the pigment complex of Glycine max (L.) Merr. plants, grown against the background of optimal and insufficient watering, to inoculation of seeds with rhizobia bacteria Bradyrhizobium japonicum, cultivated using nanocarboxylates of chromium, cobalt, iron, copper and germanium. Research has shown that utilization of germanium nanocarboxylate as a component of inoculative suspension led to the highest content of chlorophylls in leaves of soybean of the studied variants in the blossoming phase during optimal watering, as well as significant increase in the content of carotenoids compared with the control plants regardless of the level of watering. At the same time, this element caused no significant effect on the chlorophyll content in plants grown in drought. It was confirmed that among soybean plants that were in stress conditions (blossoming phase) for two weeks, the highest content of chlorophylls was in leaves of plants grown from seeds inoculated with rhizobial suspension with addition of chromium and copper nanocarboxylates, which caused 25.3% and 22.8% increase in chlorophyll а, 29.4% and 32.3% in chlorophyll b and 26.4%% and 23.8% in them respectively, compared with the control. Furthermore, chromium and copper nanocarboxylates stimulated the content of carotenoids in the same plants, though it was less expressed than after adding germanium nanocarboxylate. The highest content of photosynthetic pigments in plants after the watering was resumed (phase of bean formation) was in cases of applying chromium and germanium nanocarboxylates. It was confirmed that the most efficient way to protect the pigment complex of soybean plants during drought was using chromium and germanium nanocarboxylates as components of inoculation suspension. The results we obtained indicate the possibility of applying chromium nanocarboxylate in the technology of cultivating soybean in the conditions of water deficiency as an effective way to improve biosynthesis of chlorophylls, as well as using germanium nanocarboxyllate as a component that provides a high level of activity of protective mechanisms of the pigment system of soybean, associated with resisting stress caused by water deficiency.
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Morgun, V. V., S. Y. Kots, T. P. Mamenko, L. I. Rybachenko, and P. P. Pukhtaievych. "Regulation of superoxide dismutase activity in soybean plants by inoculating seeds with rhizobia containing nanoparticles of metal carboxylates under conditions of different water supply." Biosystems Diversity 29, no. 1 (February 25, 2021): 33–38. http://dx.doi.org/10.15421/012105.
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Soybean is one of the most profitable advanced crops in agricultural production in Ukraine and the world as a whole. Therefore, studies of means of regulation and increase in the adaptive capacity of soybeans in symbiosis with nodule bacteria under the action of unfavourable environmental factors are relevant and should be aimed at the use of complex bacterial compositions involving modern nanotechnological approaches. Nanocarboxylates of ferrum, molybdenum and germanium metals were used as components of rhizobia inoculation suspension for soybean seed treatment to study the effectiveness of their complex effect on the regulation of the activity of the key antioxidant enzyme superoxide dismutase in plants under drought. Various symbiotic systems were used, which included soybean plants and inoculation suspensions based on the active, virulent Tn5-mutant Bradyrhizobium japonicum B1-20 by adding nanoparticles of ferrum, germanium and molybdenum carboxylates to the culture medium in a ratio of 1: 1000. Citric acid was the chelator. A model drought lasting 14 days was created during the period of active fixation of atmospheric molecular nitrogen by root nodules of soybeans in the budding and flowering stages, by means of controlled watering of plants to 30% of the total moisture content. In the stage of bean formation, watering of plants was resumed to the optimal level – 60% of the total moisture content. The control was soybean plants, the seeds of which were inoculated with a suspension of rhizobia without the addition of chelated metals. The following research methods were used in the work – microbiological, physiological and biochemical. According to the results, it was found that when nanoparticles of carboxylates of ferrum, molybdenum and germanium were added to the inoculation suspension of rhizobia, there was an increase in superoxide dismutase activity in root nodules and a decrease in soybean leaves under optimal water supply conditions of plants. This indicates the initial changes in the activity of the antioxidant enzyme in these symbiotic systems, induced by the influence of chelated metals in combination with the rhizobia of the active Tn5-mutant B. japonicum B1-20. Prolonged drought induced an increase in the overall level of superoxide dismutase activity in soybean nodules and leaves, compared to plants grown under optimal watering conditions. The symbiotic system formed by soybeans and B. japonicum with molybdenum carboxylate nanoparticles was the most sensitive to long-term drought exposure, compared to two other soybean-rhizobial symbioses using ferrum and germanium nanocarboxylates. This was manifested in the unstable reaction of the enzyme to the action of drought – suppression or intensification of the level of its activity in the root nodules and leaves of soybeans inoculated with rhizobia containing molybdenum carboxylate nanoparticles. In symbiotic systems with the participation of germanium and ferrum nanocarboxylates, slight changes were revealed in superoxide dismutase activity in root nodules and leaves of plants during drought and restoration of enzyme activity to the level of plants with optimal watering after water stress. It is concluded that the addition to the culture medium of rhizobia Tn5-mutant B1-20 of nanocarboxylates of germanium or ferrum is an effective means of regulating the activity of the antioxidant enzyme superoxide dismutase in soybean root nodules and leaves, which can contribute to an increase in the protective properties and adaptation of plants to the action of dehydration.
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SHAHRAJABIAN, Mohamad H., Wenli SUN, and Qi CHENG. "The importance of Rhizobium, Agrobacterium, Bradyrhizobium, Herbaspirillum, Sinorhizobium in sustainable agricultural production." Notulae Botanicae Horti Agrobotanici Cluj-Napoca 49, no. 3 (September 10, 2021): 12183. http://dx.doi.org/10.15835/nbha49312183.
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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.
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Clafardini, G., G. Marinelli, and R. Missich. "Soil biomass of Bradyrhizobium japonicum inoculated via irrigation water." Canadian Journal of Microbiology 38, no. 6 (June 1, 1992): 584–87. http://dx.doi.org/10.1139/m92-096.
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Soybean (Glycine max (L.) Merr.), when grown in soil poor in Bradyrhizobium japonicum, shows low nitrogen-fixation activity as a result of the small number of nodules produced. In an attempt to increase the biomass of the symbiont in the soil and nodulation in soybean cv. Hodgson, a study was performed using B. japonicum USDA 122 cover inoculated with the irrigation water at the time of sowing or at the three-node (V3 phenophase) stage. The B. japonicum cover inoculation performed alone or in combination with traditional seed inoculation with peat bacteria inoculum (control) resulted in an 8-fold average increase of symbiont biomass in the soil. Cover inoculation at the V3 stage combined with seed inoculation with peat inoculum tripled the number of nodules per plant, increasing nitrogen fixation in the plant during pod filling (R6 phenophase). The ureide concentration in the soybean decreased with plant age. Cover inoculation at the V3 stage combined with seed inoculation with peat inoculum significantly increased the ureide concentration in leaves and stalks of plants in the R6 stage. The total nitrogen concentration in leaves and stalks was also always greater in the plants that were both seed and cover inoculated. Cover inoculation is a new agricultural technique that can increase nitrogen fixation and bean yield per hectare of soybean without recourse to chemical nitrogen fertilizers. Key words: Bradyrhizobium japonicum, inoculation, soil biomass.
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Maier, R. J., L. Graham, R. G. Keefe, T. Pihl, and E. Smith. "Bradyrhizobium japonicum mutants defective in nitrogen fixation and molybdenum metabolism." Journal of Bacteriology 169, no. 6 (1987): 2548–54. http://dx.doi.org/10.1128/jb.169.6.2548-2554.1987.
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Medeiros, Camila de, Gilberto Aguiar Pereira, Janyeli Dorini Silva de Freitas, Olavo Bilac Quaresma de Oliveira Filho, Juliana Silveira do Valle, Giani Andrea Linde, Luzia Doretto Paccola-Meirelles, Nelson Barros Colauto, and Fernando Gomes Barcellos. "Gene characterization of Bradyrhizobium spp. strains contrasting in biological nitrogen fixation efficiency in soybean." Semina: Ciências Agrárias 41, no. 6supl2 (November 6, 2020): 3067–80. http://dx.doi.org/10.5433/1679-0359.2020v41n6supl2p3067.
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Bacteria from genus Bradyrhizobium can establish symbiosis with soybean and supply the plant nitrogen demands via biological nitrogen fixation (BNF). This study aimed to characterize genes related to BNF efficiency in B. japonicum strains contrasting in BNF efficiency. These gene sequences were previously identified in B. japonicum (strain S370) as probably related to the BNF efficiency in soybean using a DNA subtractive technique. These genes were amplified with primers based on B. japonicum USDA110 genome. The PCR products were digested with restriction endonucleases and the RFLP products were analyzed by horizontal electrophoresis. Among the four genes, only blr3208 and blr4511 amplified for most of the strains. Neither polymorphism of the restriction profile of blr3208 and blr4511 genes nor with endonuclease for PCR-RFLP was observed. The contrasting strains had blr3208 and blr4511 genes sequenced and the multiple alignment analysis of nucleotide sequences showed the presence of preserved internal regions, confirming the analysis with PCR-RFLP. The blr3208 and blr4511 genes are highly conserved among B. japonicum strains, which may be related to adaptive function during the evolutionary process of Bradyrhizobium genus.
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Sugawara, Masayuki, Gopit R. Shah, Michael J. Sadowsky, Oleg Paliy, Justin Speck, Andrew W. Vail, and Prasad Gyaneshwar. "Expression and Functional Roles of Bradyrhizobium japonicum Genes Involved in the Utilization of Inorganic and Organic Sulfur Compounds in Free-Living and Symbiotic Conditions." Molecular Plant-Microbe Interactions® 24, no. 4 (April 2011): 451–57. http://dx.doi.org/10.1094/mpmi-08-10-0184.
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Strains of Bradyrhizobium spp. form nitrogen-fixing symbioses with many legumes, including soybean. Although inorganic sulfur is preferred by bacteria in laboratory conditions, sulfur in agricultural soil is mainly present as sulfonates and sulfur esters. Here, we show that Bradyrhizobium japonicum and B. elkanii strains were able to utilize sulfate, cysteine, sulfonates, and sulfur-ester compounds as sole sulfur sources for growth. Expression and functional analysis revealed that two sets of gene clusters (bll6449 to bll6455 or bll7007 to bll7011) are important for utilization of sulfonates sulfur source. The bll6451 or bll7010 genes are also expressed in the symbiotic nodules. However, B. japonicum mutants defective in either of the sulfonate utilization operons were not affected for symbiosis with soybean, indicating the functional redundancy or availability of other sulfur sources in planta. In accordance, B. japonicum bacteroids possessed significant sulfatase activity. These results indicate that strains of Bradyrhizobium spp. likely use organosulfur compounds for growth and survival in soils, as well as for legume nodulation and nitrogen fixation.