• 한국미생물·생명공학회지
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• 제32권2호
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• pp.190-194
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• 2004

The gene product of dctD (DctD) activates transcription from the dctA promoter regulatory region by the $\sigma^{54}$ -holoenzyme form ofRNA polymerase ($E\sigma^{54}$ ) in Rhizobium meliloti and R. leguminosarum. The Escherichia coli integration host factor (IHF) stimulated DctD-mediated activation from the dctA promoter regulatory region of R. leguminosarum but not R. meliloti. In the absence of UAS, IHF inhibited DctD-mediated activation from both of these promoter regulatory regions. IHF also inhibited activation from R. leguminosarum dctA by nitrogen regulatory protein C (NtrC), another activator of $E\sigma^{54}$ but not by one which lacks a specific binding site in this promoter regulatory region. IHF, however, stimulated NtrC-mediated activation from the R. meliloti dctA promoter. Upon removal of the UAS, IHF inhibited NtrC-mediated transcription activation from the R. meliloti dctA promoter regulatory region. These data suggest that IHF likely faciliates productive contacts between the activators NtrC or DctD and $E\sigma^{54}$ to stimulate activation from dctA promoter.

• 미생물학회지
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• 제24권3호
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• pp.211-220
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• 1986

Nitrogen fixation (nif) genes of Rhizobium leguminosarum were transferred to nif Klebsiella pneumoniae and E. coli by conjugation after partial heat induction of $RP_4$ :: Mu cts in Rhizobium $R^+$ transconjugant, and the hybrid plasmids in the transconjugant strains were isolated and characterized. In order to transfer the nif genes from Rhizobium, the hybrid plasmid $RP_4$ :: Mu cts was transferred by conjugation from E. coil to the symbiotic nitrogen fixer, R. leguminosarum. After stabillity test, the $RP_4$ :: Mu cts in Rhixobium $R^+$ transconjugant was subjected to partial heat induction by culturing it statically at $38^{\circ}C$ for 16 hours, and then conjugated with the nif defective mutant strains of K. pneumoniae or nif mutant strains of E. coli having whole nif gene plasmid. Recombinant strains of K. pneumoniae, which could grow in a N-free medium and exhibit the nitrogenase activity were selected. However, in the case of E. coli, they could grow well in a NA medium containing antibiotices, but hardly frow in a N-free medium. The hybrid plasmids in these transconjugal strains were isolated by gel electrophoresis and compared their molecular sizes.

• 미생물학회지
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• 제23권2호
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• pp.107-114
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• 1985

우리나라 자연환경으로부터 분리한 Rhizob ium 32권주로부터 카나마이신, 세트라싸이클린 등에는 예민하고, 클로람페니콜, 젠타마이신 등에는 강한 내성을 나타내는 5 균주를 선별하고, 이를 수용세포로하여 RP4::Mu cts를 접함에 의해 E. coli로부터 Rhizobium leguminosarum으로 전달 시켰다. 그 전달빈도는 $5.8{\times}10^{-7}$의 빈도를 나타내었다. 접합체에서의 RP4::Mu cts플라스미드의 존재는 암피실린과 카나마이신, 테트라싸이클린에 대한 내정과 $42^{\circ}C$에서의 플라크 형성으로 확인하였다. 접합체들은 $10^2~10^3$단위로 플라크를 형성하였고, 안정성를 조사한 신파 4주 후에도 대부분이 RP4: :Mu cts의 성질을 유지하고 있는 것으로 나타났다.

• 한국토양비료학회지
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• 제50권6호
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• pp.562-573
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• 2017

Some symbiotic characteristics of native Korean Rhizobium leguminosarum biovar viciae were analysed to get some informations desirable for cultivation of hairy vetch (Vicia villosa Roth) using its symbiont in Korea. The size of indigenous populations of R. leguminosarum biovar viciae was higher in seven upland soils showing $1.7{\times}10^2{\sim}5.8{\times}10^4cells\;g{\cdot}soil^{-1}$, which appeared to be 10% and 37% higher for cultivated and uncultivated soils of hairy vetch, respectively, than seven paddy soils with $1.7{\times}10^2{\sim}1.7{\times}10^4cells\;g{\cdot}soil^{-1}$. In symbiotic potentials, however, the yields of hairy vetch treated with 10-fold-diluted ($10^{-1}$) inoculum and 1000-fold-diluted ($10^{-3}$) one was 11.2% and 8.8% more, respectively, in paddy than upland. Hairy vetch inoculated with either strain KHR 106 from Sacheon or strain KHR 120 from Yesan among native Korean R. leguminosarum biovar viciae isolates was of similar yield increment of 16% (p < 0.05) in upland soils with native R. leguminosarum biovar viciae of $5.8{\times}10cells\;g{\cdot}soil^{-1}$. In case of coinoculation of the two strains, however, the yields was not significantly increased. In especial, isolate KHR 106, KHR 120, and KHR 122 from Suwon, which has also good symbiotic effectiveness, showed different protein profile patterns each other. As a result, hairy vetch is possibly able to use atmospheric nitrogen through symbiotic relationship with diverse native R. leguminosarum biovar viciae in Korean arable lands. For safe and good production of hairy, however, the use of superior strains with high symbiotic effectiveness and competitiveness will be desirable.

• Journal of Microbiology and Biotechnology
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• 제24권9호
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• pp.1162-1169
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• 2014

Glyphosate is the active component of the top-selling herbicide, the phytotoxicity of which is due to its inhibition of the shikimic acid pathway. 5-Enolpyruvylshikimate-3-phosphate synthase (EPSPS) is a key enzyme in the shikimic acid pathway. Glyphosate tolerance in plants can be achieved by the expression of a glyphosate-insensitive aroA gene (EPSPS). In this study, we used a PCR-based two-step DNA synthesis method to synthesize a new aroA gene ($aroA_{R.\;leguminosarum}$) from Rhizobium leguminosarum. In vitro glyphosate sensitivity assays showed that $aroA_{R.\;leguminosarum}$ is glyphosate tolerant. The new gene was then expressed in E. coli and key kinetic values of the purified enzyme were determined. Furthermore, we transformed the aroA gene into Arabidopsis thaliana by the floral dip method. Transgenic Arabidopsis with the $aroA_{R.\;leguminosarum}$ gene was obtained to prove its potential use in developing glyphosate-resistant crops.

• Applied Microscopy
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• 제8권1호
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• pp.9-15
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• 1978

Five strains of the Genus Rhizobium were isolated from the nodules of five leguminous plants respectively. They were identified according to Bergey's Manual together with the results of Vincent. The flagella of each strains were observed by electron microscope using negative staining with PTA and metal shadowing with chromium. Five host plants and identified Rhizobium strains were as. follows. Pisum sativum.....R. leguminosarum Phaseolus vulgaris.....R. phaseoli Trifolium repens.....R. trifolii Glycine max.....R. japonicum Lupinus grandiflorus.....R. lupini Electron micrographs showed that R. leguminosarum and R. phaseoli had 4 peritrichous flagella, where as R. trifolii had 5 peritrichous flagella. On the other hand, R. japonicum and R. lupini had 1 subpolar flagellum.

• BMB Reports
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• 제34권4호
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• pp.305-309
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• 2001

MatR in Rhizobium trifolii is a malonate-responsive transcription factor that regulates the expression of genes, matABC, enabling decarboxylation of malonyl-CoA into acetyl-CoA, synthesis of malonyl-CoA from malonate and CoA, and malonate transport. According to an analysis of the amino acid sequence homology, MatR belongs to the GntR family The proteins of this family have two-domain folds, the N-terminal helix-turn-helix DNA-binding domain and the C-terminal ligand-binding domain. In order to End the malonate binding site and amino acid residues that interact with RNA polymerase, a site-directed mutagenesis was performed. Analysis of the mutant MatR suggests that Arg-160 might be involved in malonate binding, whereas Arg-102 and Arg-174 are critical for the repression activity by interacting with RNA polymerase.

• 미생물학회지
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• 제22권2호
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• pp.73-76
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• 1984

From the root nodules of legumes distributed in South Korea, 74 strains of Rhizobium were isolated. The strains isolated were identified based on Bergey's Manual and Vincent's identification key. Following 5 species of Rhizobium were confirmed. R. leguminosarum, R. meliloti, R. phaseoli, R. trifolii, and R. japonicum

• Bulletin of the Korean Chemical Society
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• 제27권9호
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• pp.1485-1488
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• 2006

• 미생물학회지
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• 제27권4호
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• pp.398-403
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• 1989

The root nodule of Canavalia lineta was classified as a determinate nodule and the symbiont as a Rhizobium-bacteriod based on their morphological characteristics. Isolated encosymbiont was similar both to R. leguminosarum and R. meliloti in its peritrichous arrangement of flagella and some of the physiological characteristics. Compared to control plants, Canavalia seedlings inoculated with the isolate grew normally due to induced root nodules, confirming isolate's infectivity and effectivity. Characteristics of the reisolated endosymbiont from induced root nodule were identical to those of the first isolate, indicating the nodules were induced by the first isolate. From these results, it was confirmed that Rhizobium strain isolated from the root nodules of Canavalia lineata was a real symbiont, and was named Rhizobium sp. SNU003.