| rhizobium ciceri sp. nov., consisting of strains that nodulate chickpeas (cicer arietinum l.). | the taxonomic status of 16 collection strains of chickpea (cicer arietinum l.) rhizobia which were previously determined to belong to two groups (groups a and b) were compared with reference strains belonging to different genera and species of the family rhizobiaceae. we used the following taxonomic, phylogenetic, and phenotypic characteristics and approaches to study these organisms: dna homology, guanine-plus-cytosine content, restriction fragment length polymorphism of the amplified 16s-inter ... | 1994 | 7520739 |
| genomic heterogeneity of strains nodulating chickpeas (cicer arietinum l.) and description of rhizobium mediterraneum sp. nov. | the genetic diversity of chickpea strains was studied by using 30 isolates obtained from nodules on chickpeas growing in uninoculated fields over a wide geographic range. the following taxonomic approaches were used: dna-dna relatedness analysis, restriction fragment length polymorphism analysis of the amplified 16s ribosomal dna (rdna) intergenic spacer (igs), and total 16s rrna sequence analysis. the division of chickpea-infective strains into two major phylogenetic groups (groups a and b) tha ... | 1995 | 7547282 |
| proposal for rejection of agrobacterium tumefaciens and revised descriptions for the genus agrobacterium and for agrobacterium radiobacter and agrobacterium rhizogenes. | the 16s rrna sequences of seven representative agrobacterium strains, eight representative rhizobium strains, and the type strains of azorhizobium caulinodans and bradyrhizobium japonicum were determined. these strains included the type strains of agrobacterium tumefaciens, agrobacterium rhizogenes, agrobacterium radiobacter, agrobacterium vitis, agrobacterium rubi, rhizobium fredii, rhizobium galegae, rhizobium huakuii, rhizobium leguminosarum, rhizobium loti, rhizobium meliloti, and rhizobium ... | 1993 | 8240952 |
| four unnamed species of nonsymbiotic rhizobia isolated from the rhizosphere of lotus corniculatus. | previously, we found that genetically diverse rhizobia nodulating lotus corniculatus at a field site devoid of naturalized rhizobia had symbiotic dna regions identical to those of icmp3153, the inoculant strain used at the site (j. t. sullivan, h. n. patrick, w. l. lowther, d. b. scott, and c. w. ronson, proc. natl. acad. sci. usa 92:8985-8989, 1995). in this study, we characterized seven nonsymbiotic rhizobial isolates from the rhizosphere of l. corniculatus. these included two from plants at t ... | 1996 | 8702274 |
| biodegradation of phosphonomycin by rhizobium huakuii pmy1. | the biodegradation by rhizobium huakuii pmy1 of up to 10 mm phosphonomycin as a carbon, energy, and phosphorus source with accompanying p(i) release is described. this biodegradation represents a further mechanism of resistance to this antibiotic and a novel, phosphate-deregulated route for organophosphonate metabolism by rhizobium spp. | 1998 | 9435089 |
| selection of eps-deficient mutants (exo-) from rhizobiun huakuii 107 by region-directed tn5 mutagenesis. | pjb-b5 was a recombinant plasmid of prk415 containing the 5.9 kb b5 fragment from exor'-11. after pjb-b5 was mutagenized by mt614 (mal::tn5), 10 plasmids tn1-1, tn1-12, tn2-2, tn2-3, tn3-1, tn4-1, tn9-1, tn10-1, tn13-1, and tn14-1 with different tn5 insertions in the b5 fragment were constructed. by conjugation of tn1-1, etc., into rhizobium huakuii 107 containing the p-group plasmid pph1ji which is incompatible with prk415, and simultaneous selection for rifr (conferred by strain 107), gm(r) (c ... | 1998 | 9759544 |
| occurrence of choline and glycine betaine uptake and metabolism in the family rhizobiaceae and their roles in osmoprotection | the role of glycine betaine and choline in osmoprotection of various rhizobium, sinorhizobium, mesorhizobium, agrobacterium, and bradyrhizobium reference strains which display a large variation in salt tolerance was investigated. when externally provided, both compounds enhanced the growth of rhizobium tropici, sinorhizobium meliloti, sinorhizobium fredii, rhizobium galegae, agrobacterium tumefaciens, mesorhizobium loti, and mesorhizobium huakuii, demonstrating their utilization as osmoprotectan ... | 1999 | 10224003 |
| structure of the mesorhizobium huakuii and rhizobium galegae nod factors: a cluster of phylogenetically related legumes are nodulated by rhizobia producing nod factors with alpha,beta-unsaturated n-acyl substitutions. | rhizobia are symbiotic bacteria that synthesize lipochitooligosaccharide nod factors (nfs), which act as signal molecules in the nodulation of specific legume hosts. based on the structure of their n-acyl chain, nfs can be classified into two categories: (i) those that are acylated with fatty acids from the general lipid metabolism; and (ii) those (= alphau-nfs) that are acylated by specific alpha,beta-unsaturated fatty acids (containing carbonyl-conjugated unsaturation(s)). previous work has de ... | 1999 | 10564467 |
| the glutamine synthetases of rhizobia: phylogenetics and evolutionary implications. | glutamine synthetase exists in at least two related forms, gsi and gsii, the sequences of which have been used in evolutionary molecular clock studies. gsi has so far been found exclusively in bacteria, and gsii has been found predominantly in eukaryotes. to date, only a minority of bacteria, including rhizobia, have been shown to express both forms of gs. the sequences of equivalent internal fragments of the gsi and gsii genes for the type strains of 16 species of rhizobia have been determined ... | 2000 | 10677854 |
| analysis of cellular fatty acids and phenotypic relationships of agrobacterium, bradyrhizobium, mesorhizobium, rhizobium and sinorhizobium species using the sherlock microbial identification system. | previous studies have demonstrated that cellular fatty acid analysis is a useful tool for identifying unknown strains of rhizobia and establishing taxonomic relationships between the species. in this study, the fatty acid profiles of over 600 strains belonging to the genera agrobacterium, bradyrhizobium, mesorhizobium, rhizobium and sinorhizobium were evaluated using the gaschromatography-based sherlock microbial identification system (mis). data collected with the mis showed that the three phyl ... | 2000 | 10758890 |
| phylogenetic diversity of rhizobial strains nodulating robinia pseudoacacia l. | lack of knowledge exists regarding the diversity of rhizobial strains nodulating black locust (robinia pseudoacacia l.), which is a neophytic tree species widely distributed in europe. seventeen rhizobial strains isolated from nodules of black locust at a german location were examined by phenotypic characterization and 16s rdna analysis. the isolates were classified in nine 16s rdna genotypes using a set of seven endonucleases. based on rflp analysis and sequencing, the strains were shown to bel ... | 2000 | 11065378 |
| the involvement of a cysteine proteinase in the nodule development in chinese milk vetch infected with mesorhizobium huakuii subsp. rengei. | cys proteinases play important roles in plant cell development and senescence. a cdna, asnodf32, obtained by differential screening of a nodule cdna library of the leguminous plant chinese milk vetch (astragalus sinicus), represents a nodule-specific cys proteinase similar to that reported for the actinorhizal alnus glutinosa-flankia symbiosis. a characteristic feature of this proteinase is the presence of a putative vacuolar targetting signal, lqda, within its propeptide. expression of the asno ... | 2000 | 11080286 |
| structure of the o-specific polysaccharide of mesorhizobium huakuii ifo15243t. | the structure of the o-specific polysaccharide isolated by mild acid hydrolysis of the lipopolysaccharide of mesorhizobium huakuii ifo15243t was studied using methylation analysis and various one- and two-dimensional 1h and 13c nmr experiments. the o-antigen polysaccharide was found to be linear polymer constituted by a trisaccharide repeating unit of the following structure: --> 2)-alpha-l-6dtalp-(1 --> 3)-alpha-l-6dtalp-(1 --> 2)-alpha-l-rhap-(1 -->. | 2000 | 11117330 |
| [nucleotide sequence of the rhizobium huakuii common nodution genes noda and nodbc]. | an another clone pran109 which contains nod genes was isolated and identified from the clone bank of r. huakuii 159 dna using the 32p-labeled 2.3 kb r. meliloti nod dna fragment as a hybridization probe. analysis of homologous dna-dna hybridization and nucleotide sequence indicated that the 9 kb ecori fragment of pran109 dna carried the nodd1bc genes and the 18 kb ecori fragment of pran109 dna contained nodd2a genes. the common noda gene was separated by 6.7 kb from the nodbc genes. both the nod ... | 1997 | 11189360 |
| dna synthesis and fragmentation in bacteroids during astragalus sinicus root nodule development. | histo- and cytochemical techniques were used to study the dna replication and fragmentation patterns in bacteroids formed by mesorhizobium huakuii subsp. rengei in nodules of astragalus sinicus. dna replication was detected by the incorporation of 5-bromo deoxy-uridine. signals denoting dna synthesis were observed in plant nuclei within the nodule meristem and in bacteroids near the meristem. the tunel (tdt-mediated dutp nick-end labeling) assay was used to measure dna fragmentation. in nutrient ... | 2001 | 11330661 |
| ismh2, a novel insertion sequence-like element associated with nifa from mesorhizobium huakuii. | sequence analysis of the nifa gene, including its 5' flanking region, of mesorhizobium huakuii revealed the presence of a novel is-like element called ismh2. it is 828 bp in length and possesses two imperfect terminal inverted repeats of 14 bp with only one mismatch. the putative transposase encoded by ismh2 is composed of 204 amino acids. in comparison with other insertion sequences ismh2 likely belongs to the is6 family. multiple copies of ismh2 were detected in the genome of m. huakuii 159 by ... | 2001 | 11535031 |
| cloning and sequencing of rhizobium huakuii exoa gene encoding a glucosyl-transferase. | from exor'-11 which could complement two exo(-) mutants of r. huakuii 107: na03 and na10, a 2.0kb bgli fragment was subcloned in prk415. the resulted plasmid pjb-h701 could restore the exo(-) phenotype of na03 and na10. the complete nucleotide sequence of the fragment was determined, which contains the structural genes of a glucosyl-transferase, as well as the 5'- and 3'- flanking regions. an open reading frame of 984 base pairs was identified as r. huakuii exoa gene. the mw of exoa, as deduced ... | 1998 | 12168029 |
| analysis of the exo(-) mutant of rhizobium huakuii and their exopolysaccharide component. | we have subcloned two plasmids, pws-6bp1 and pws-6bp2, from the 8.5 kb dna fragment of plasmid pjb22-b6. the plasmid of pws-6bp1, with a 5.8 kb dna fragment, can complement the exopolysaccharide-deficient mutant na06 and na12 of rhizobium huakuii strain 107, but the plasmid pws-6bp2, with a 2.6 kb dna fragment can only complement na12. the effective nodules formed by the wild type strain 107 (rh107) contain lots of bacteriods; the ineffective nodules formed by the mutant na06 and na12 contain fe ... | 1998 | 12174297 |
| sequence analysis of the exo1 gene involved in the exopolysaccharide synthesis of rhizobium huakuii. | the 2.6 kb fragment which can complement the exo(-)ndv(-)fix(-) mutants of r. huakuii to exo(+)nod(+)fix(+) was sequenced. the result revealed the presence of an open reading frame exo1, which encodes 340 amino acids. analysis of the hydrophobicity plot of the putative protein indicated that it was a cytoplasmic protein. exo1 displayed strong homology to the exou protein of r. meliloti, which was a glucosyltransferase. a transcriptional fusion to lacz using the promoterless vector pmp221 showed ... | 1997 | 12215788 |
| a novel bioremediation system for heavy metals using the symbiosis between leguminous plant and genetically engineered rhizobia. | a novel plant-bacterial remediation system for heavy metals (hm) was developed by expression of tetrameric human metallothionein (mtl4) in mesorhizobium huakuii subsp. rengei b3, a strain which infects and forms nodules on a green manure, astragalus sinicus. the mtl4 gene was fused to the nifh and nolb promoters, which generated nodule- specific expression of the mtl4 gene. the expression analysis of the mtl4 gene was demonstrated in free-living cells in the presence of cd(2+) and cu(2+), under ... | 2002 | 12385715 |
| lipopolysaccharides from mesorhizobium huakuii and mesorhizobium ciceri: chemical and immunological comparative data. | lipopolysaccharides of two mesorhizobium species of different host specificity were compared: m. huakuii and m. ciceri. m. huakuii sp. was represented by five strains with special consideration of m. huakuii ifo 15243(t). sds/page profiles revealed that all m. huakuii lps preparations contained low molecular mass fractions (lps-ii) of the same molecular size. all of lipopolysaccharides contained high molecular mass fractions (lps-i). however, the high molecular mass fraction from each strain pos ... | 2002 | 12545212 |
| [identification and functional analysis of nifa from mesorhizobium huakuii 159]. | the nifa gene from mesorhizobium huakuii 159 was identified and sequenced. an open reading frame coding for 44734d. nifa protein would detected. comparison of the deduced amino acid sequence with other nifa proteins revealed the presence of the conserved central domain and the c-terminal dna-binding domains. but the predicted m. huakuii nifa protein lacked a n-terminal domain that is present in the homologous proteins. mutants with nif- phenotype were obtained by site-directed tn5 mutagenesis. a ... | 2000 | 12548989 |
| [cloning and analysis of the regulatory gene fragment induced with seed extract in rhizobium huakuii strain 7653r]. | the large plasmids of strain 7653r were digested with restriction enzyme ecori. their dna fragments were cloned into the expression vector pmp220 to construct a lacz fusion pool, which were transferred into the recipient strain 7653r. tri-transconjugants were selected onto plates containing x-gal and seed extract. five blue colonies were assayed of their beta-galactosidase activity after incubation with or without seed extract. a positive induced strain hn18 was obtained. hybridization of noddab ... | 1998 | 12549337 |
| enhanced accumulation of cd2+ by a mesorhizobium sp. transformed with a gene from arabidopsis thaliana coding for phytochelatin synthase. | we expressed the arabidopsis thaliana gene for phytochelatin synthase (pcs(at)) in mesorhizobium huakuii subsp. rengei b3, a microsymbiont of astragalus sinicus, a legume used as manure. the pcs(at) gene was expressed under the control of the nifh promoter, which regulates the nodule-specific expression of the nifh gene. the expression of the pcs(at) gene was demonstrated in free-living cells under low-oxygen conditions. phytochelatin synthase (pcs) was expressed and catalyzed the synthesis of p ... | 2003 | 12620871 |
| agrobacterium bioassay strain for ultrasensitive detection of n-acylhomoserine lactone-type quorum-sensing molecules: detection of autoinducers in mesorhizobium huakuii. | an ultrasensitive bioassay system for the detection of n-acylhomoserine lactones (ahls) was constructed in agrobacterium tumefaciens by using the t7 expression system to overproduce the ahl receptor trar. this strain detected many diverse ahls, some at extremely low concentrations. we used this strain to detect for the first time ahls made by mesorhizobium huakuii, which symbiotically fixes nitrogen in association with the legume astragalus sinicus, a source of green manure throughout eastern as ... | 2003 | 14602662 |
| characterisation of mesorhizobium huakuii cyclic beta-glucan. | periplasmic and extracellular glucans of mesorhizobium huakuii were isolated and characterized by compositional and maldi-tof analyses, as well as 1h and 13c nmr spectroscopy. it was shown that m. huakuii produces a cyclic beta-glucan composed entirely of nonbranched glucose chains and unmodified by nonsugar substituents. the degree of polymerisation of the cyclic oligosaccharides was estimated to be in the range from 17 to 28. the most abundant glucan molecules contained 22 glucose residues. gl ... | 2003 | 14740013 |
| characterization of mesorhizobium huakuii lipid a containing both d-galacturonic acid and phosphate residues. | the chemical structure of the free lipid a isolated from mesorhizobium huakuii ifo 15243(t) was elucidated. lipid a is a mixture of at least six species of molecules whose structures differ both in the phosphorylation of sugar backbone and in fatty acylation. the backbone consists of a beta (1'-->6) linked 2,3-diamino-2,3-dideoxyglucose (dag) disaccharide that is partly substituted by phosphate at position 4'. the aglycon of the dag-disaccharide has been identified as alpha-d-galacturonic acid. ... | 2004 | 15030481 |
| curing of symbiotic plasmid of mesorhizobium huakuii subsp. rengei isolated from astragalus sinicus. | astragalus sinicus (chinese milk vetch), a green manure leguminous plant, harbors mesorhizobium huakuii subsp. rengei strain b3 in the root nodules. the visualization of symbiotic plasmid of strain b3 showed the presence of one sym plasmid of about 425 kbp. curing of sym plasmid by temperature and acrydine orange was studied. growing rhizobial cells at high temperature (37 degrees c) or treating the cells with acrydine orange at 50 mg/l eliminated sym plasmid of m. huakuii strain b3, which was c ... | 2003 | 15248496 |
| heterologous overexpression of quorum-sensing regulators to study cell-density-dependent phenotypes in a symbiotic plant bacterium mesorhizobium huakuii. | quorum-sensing is widespread among many prokaryotic lineages. in order to investigate quorum regulation in the plant bacterium mesorhizobium huakuii which produces an n-acyl homoserine lactone (ahl) quorum signal, the agrobacterium quorum-sensing regulator trar was heterologously expressed in this bacterium. the resulting strains showed reduced ahl production in the supernatant compared to wild-type, but similar intracellular levels of ahls were detected, suggesting that m. huakuii ahls can be b ... | 2004 | 15480575 |
| mini transposon vector mediated foreign gene expression in mesorhizobium huakuii subsp. rengei. | among the transposable elements, mini-tn5 transposon vector has proven to be of greater utility for insertion mutagenesis of variety of gram negative bacteria. the mini-tn5 vector containing promoter less egfp gene and gentamycin resistant gene was used for the present study. the transposon vector was introduced to m. huakuii from e. coli s17 by conjugation. the conjugants were screened for stable expression of egfp both in free-living and in nodules of astragalus sinicus. the result showed that ... | 2004 | 15511011 |
| characteristics of the rhizobia associated with dalea spp. in the ordway, kellogg-weaver dunes, and hayden prairies. | habitat fragmentation affects the biodiversity and function of aboveground organisms in natural ecosystems but has not been studied for effects on belowground species. in this paper, we consider the diversity of the rhizobia associated with the indigenous legume dalea purpurea in 3 residual prairie areas in minnesota and iowa. using dalea purpurea as a trap host, 218 rhizobia were recovered from these soils then characterized using boxa1r pcr. three major and 13 minor groups were distinguished b ... | 2005 | 15782230 |
| [study on ahl-like quorum signals in mesorhizobium huakuii]. | quorum sensing is a mechanism used by single-cell bacteria to monitor their population density and control a variety of physiological functions in a cell-density-dependent manner. an ultrasensitive quorum signal acyl-homoserine lactone (ahl) detecting agrobacterium tumefaciens strain, which strongly overproduces quorum-sensing regulator trar and was proved to be able to detect ahls at nano-molar concentration, was used to detect the production of ahls in three mesorhizobium huakuii strains. we s ... | 2005 | 15847155 |
| phylogenetic position of mesorhizobium huakuii subsp. rengei, a symbiont of astragalus sinicus cv. japan. | the phylogenetic position of rhizobium huakuii bv. renge, a symbiont of astragalus sinicus cv. japan (renge-sou), was studied. the following phylogenetic approaches were used: restriction fragment length polymorphism (rflp)-polymerase chain reaction (pcr) analysis of a full-length 16s rdna fragment, 16s rdna analysis of the first 300-bp sequence, bacteriophage typing, and amplification of the genomic region by random primer. all the data suggest that strains of r. huakuii bv. renge should be cla ... | 1999 | 16232424 |
| efficient transformation of mesorhizobium huakuii subsp. rengei and rhizobium species. | the transformation of mesorhizobium huakuii subsp. rengei b3 with either pbbr122 or pkt230 was carried out. we determined the optimal conditions required for transformation by electroporation and obtained up to 10(5) cfu/microg pbbr122. plasmids prepared from strain b3 yielded higher transformation efficiency than those from various dam or dcm mutant strains of escherichia coli. this result suggests that a high transformation efficiency is not related to the methylation of plasmid dna in e. coli ... | 2000 | 16232796 |
| cloning and identification of opa22, a new gene involved in nodule formation by mesorhizobium huakuii. | using tn5-sacb insertion mutagenesis, 3000 mutants were obtained from mesorhizobium huakuii 7653r. eight nodulation-defective mutants were screened by plant nodulation experiments. the dna sequences of the contiguous region from the tn5 insertion site were determined by thermal asymmetric interlaced pcr. a new gene was cloned and designated opa22, as judged from its structural and functional homology. sequence analysis indicated that opa22 was composed of 774 nucleotides and encoded a protein of ... | 2006 | 16553846 |
| bioremediation of cadmium contaminated soil using symbiosis between leguminous plant and recombinant rhizobia with the mtl4 and the pcs genes. | cadmium contamination in rice grains is one of the important issues in asian countries. we have developed a novel bio-remediation system based on the symbiosis between leguminous plant and genetically engineered rhizobia. we designed two types of recombinant rhizobia, carrying two genes, synthetic tetrameric metallothionein (mtl4) and cdna encoding phytochelatin synthase from arabidopsis thaliana (atpcs). the mtl4 and atpcs genes were transferred to mesorhizobium huakuii subsp. rengei b3, which ... | 2007 | 16950497 |
| cloning and identification of lpsh, a novel gene playing a fundamental role in symbiotic nitrogen fixation of mesorhizobium huakuii. | mesorhizobium huakuii 7653r forms a symbiotic relationship with astragalus sinicus to produce nitrogen-fixing root nodules under nitrogen-limiting conditions. by screening its transposon-inserted mutant library, a mutation in the lpsh gene was found to form pseudonodules on a. sinicus. its effect was further confirmed by double-crossover mutant hk242. dna sequence analysis revealed that the lpsh gene encodes a deduced protein of 397 amino acids with a predicted molecular mass of 43.6 kd. lpsh co ... | 2007 | 17486406 |
| the function of three indigenous plasmids in mesorhizobium huakuii 2020 and its symbiotic interaction with sym pjb5ji of rhizobium leguminosarum. | a mesorhizobium huakuii strain 2020, isolated from a rice-growing field in southern china, contains three indigenous plasmids named p2020a, p2020b and p2020c, respectively. the plasmids were deleted via tn5-sacb insertion, and two cured derivatives were obtained. interestingly, the mutant 2020d29 curing of p2020c could significantly enhance the capacity of symbiotic nitrogen fixation. but the mutant 2020d8 curing of p2020b lost the ability to nodulate astragalus sinicus. furthermore, the third p ... | 2008 | 18368313 |
| different mesorhizobium species associated with caragana carry similar symbiotic genes and have common host ranges. | fourteen strains representing 11 caragana-nodulating mesorhizobium genomic species were identified as representing mesorhizobium amorphae, mesorhizobium huakuii, mesorhizobium septentrionale and groups related to mesorhizobium plurifarium, mesorhizobium temperatum, mesorhizobium tianshanense and mesorhizobium mediterraneum by sequencing of the 16s rrna gene, 16s-23s internal transcribed spacer, partial housekeeping reca gene, and previously performed sodium dodecyl sulfate polyacrylamide gel ele ... | 2008 | 18422620 |
| promotion of metal accumulation in nodule of astragalus sinicus by the expression of the iron-regulated transporter gene in mesorhizobium huakuii subsp. rengei b3. | toxic metal contamination in agricultural fields is an important worldwide problem. in previous studies, we developed a bioremediation system based on the symbiosis between astragalus sinicus and the recombinant rhizobium, mesorhizobium huakuii subsp. rengei b3 developed by overexpressing a synthetic tetrameric metallothionein gene (mtl4) and cdna encoding the phytochelatin synthase from arabidopsis thaliana (atpcs). to promote the transport of metals into the nodules of the rhizobium and the ac ... | 2008 | 18640604 |
| diverse bacteria isolated from root nodules of wild vicia species grown in temperate region of china. | in the present study, a total of 154 bacterial strains isolated from nodules of eighteen vicia species mainly grown in the temperate chinese provinces were characterized by ardra, its pcr-rflp, box-pcr, sequencing of 16s rdna, nodc, nifh, atpd and glnii, and nodulation tests. the results demonstrated that most of the r. leguminosarum strains were effective microsymbionts of the wild vicia species, while genomic species related to rhizobium gallicum, mesorhizobium huakuii, ensifer meliloti and br ... | 2008 | 18704366 |
| stress tolerance, genetic analysis and symbiotic properties of root-nodulating bacteria isolated from mediterranean leguminous shrubs in central spain. | nine root-nodulating bacterial isolates were obtained from the leguminous shrubs spartium junceum, adenocarpus hispanicus, cytisus purgans, cytisus laburnuum, retama sphaerocarpa and colutea arborescens in areas of central spain. a poliphasic approach analyzing phenotypic, symbiotic and genetic properties was used to study their diversity and characterize them in relation to mediterranean conditions. stress tolerance assays revealed marked variations in salinity, extreme ph and cadmium tolerance ... | 2009 | 18784916 |
| baca is indispensable for successful mesorhizobium-astragalus symbiosis. | a homologue of sinorhizobium meliloti baca was isolated from mesorhizobium huakuii 7653r, which is capable of fixing atmospheric nitrogen in symbiotic association with leguminous astragalus sinicus (chinese milk vetch). inactivation of the baca gene abolished the ability of m. huakuii 7653r to establish a successful symbiosis with its host plant. simultaneously, compared with wild-type m. huakuii 7653r, the baca mutant was more sensitive to cell envelope-disrupting agents (acidic solution, ethan ... | 2009 | 19352651 |
| survey of chickpea rhizobia diversity in portugal reveals the predominance of species distinct from mesorhizobium ciceri and mesorhizobium mediterraneum. | several mesorhizobium species are able to induce effective nodules in chickpea, one of the most important legumes worldwide. our aims were to examine the biogeography of chickpea rhizobia, to search for a predominant species, and to identify the most efficient microsymbiont, considering portugal as a case study. one hundred and ten isolates were obtained from continental portugal and madeira island. the 16s ribosomal rna gene phylogeny revealed that isolates are highly diverse, grouping with mos ... | 2009 | 19468700 |
| studies on the biodegradation of fosfomycin: growth of rhizobium huakuii pmy1 on possible intermediates synthesised chemically. | the first step of the mineralisation of fosfomycin by r. huakuii pmy1 is hydrolytic ring opening with the formation of (1r,2r)-1,2-dihydroxypropylphosphonic acid. this phosphonic acid and its three stereoisomers were synthesised by chemical means and tested as their ammonium salts for mineralisation as evidenced by release of p(i). only the (1r,2r)-isomer was degraded. a number of salts of phosphonic acids such as (+/-)-1,2-epoxybutyl-, (+/-)-1,2-dihydroxyethyl-, 2-oxopropyl-, (s)-2-hydroxypropy ... | 2009 | 19590792 |
| horizontal gene transfer and recombination shape mesorhizobial populations in the gene center of the host plants astragalus luteolus and astragalus ernestii in sichuan, china. | thirty-three rhizobial strains isolated from the root nodules of astragalus luteolus and astragalus ernestii growing on the west plateau at two different altitudes in sichuan province, china, were characterized by amplified rdna restriction analysis (ardra), amplified fragment length polymorphism (aflp), and by sequencing of rrs, glna, glnii and nifh. the ardra analysis revealed considerable genomic diversity. in aflp analysis, 20 of 33 astragalus rhizobia formed three distinct clades, with othe ... | 2009 | 19796139 |
| [cloning and identification of the plasmid replication gene repc in mesorhizobium huakuii]. | the repc gene is the principal initiation protein gene for plasmid replication. we identified the repc-like sequences from mesorhizobium huakuii strain hn3015 and its derivatives of plasmid curing. | 2009 | 20112674 |
| incompatibility behavior of a symbiotic plasmid pmh7653rb in mesorhizobium huakuii 7653r. | mesorhizobium huakuii strain 7653r harbored two indigenous plasmids named pmh7653ra and pmh7653rb. the larger plasmid pmh7653rb (symbiotic plasmid) was transferred to m. huakuii hn308sr harboring three plasmids: pmhhn308a, pmhhn308b and pmhhn308c, and hn3015sr harboring three plasmids: pmhhn3015a, pmhhn3015b and pmhhn3015c by tri-parent mating. two stable indigenous plasmids, pmhhn308b and pmhhn308c of hn308sr, were co-eliminated due to the introduction of pmh7653rb, and the transconjugant was n ... | 2010 | 20602277 |
| synthesis of the 6-deoxytalose-containing tri- and hexasaccharides of the o-antigen polysaccharide from mesorhizobium huakuii ifo15243t. | the synthesis of a trisaccharide and a hexasaccharide, the monomer and dimer of the repeating unit of o-antigen polysaccharide from mesorhizobium huakuii ifo15243, has been accomplished through suitable protecting group manipulations and stereoselective glycosylation reactions starting from commercially available l-rhamnose. the target oligosaccharides in the form of their p-methoxyphenyl glycosides are suitable for further glycoconjugate formation via selective cleavage of this group. | 2010 | 20692653 |
| low endotoxic activity of lipopolysaccharides isolated from bradyrhizobium, mesorhizobium, and azospirillum strains. | the endotoxic activities of lipopolysaccharides (lps) isolated from different strains of rhizobia and rhizobacteria (bradyrhizobium, mesorhizobium, and azospirillum) were compared to those of salmonella enterica sv. typhimurium lps. the biological activity of all the examined preparations, measured as limulus lysate gelation, production of tumor necrosis factor (tnf), interleukin-1β (il-1β), and interleukin-6 (il-6), and nitrogen oxide (no) induction in human myelomonocytic cells (line thp-1), w ... | 2010 | 21091983 |
| tolerance of mesorhizobium type strains to different environmental stresses. | the symbiosis between rhizobia and legumes is affected by different environmental conditions. our aims were to evaluate stress tolerance of mesorhizobium species and investigate species-specific stress response mechanisms. tolerance of mesorhizobium type strains to temperature, salt and ph stress was evaluated. mesorhizobium thiogangeticum showed highest growth with 1.5% nacl and mesorhizobium ciceri at ph 5. mesorhizobium plurifarium showed higher growth at 37°c. sds-page analysis revealed chan ... | 2010 | 21152981 |
| [construction of astragalus sinicus ad-cdna library and identification of proteins interact with the leghemoglobin]. | the objectives of this work were (i) to construct a yeast two-hybrid ad-cdna library of astragalus sinicus and provide a fundamental system to screen target proteins involved symbiotic nitrogen fixation, and (ii) to isolate the target proteins interacting with the leghemoglobin. | 2010 | 21365913 |
| structural studies of the o-specific polysaccharide from the lipopolysaccharide of mesorhizobium huakuii strain s-52, the symbiotic partner of astragalus sinicus. | the o-specific polysaccharide (ops) obtained by mild-acid degradation of the lipopolysaccharide isolated from mesorhizobium huakuii strain s-52 was studied by sugar and ethylation analyses along with (1)h and (13)c nmr spectroscopy. it was concluded that the ops was composed of trisaccharide repeating units containing two residues of 6-deoxy-l-talose (6dtal) and one l-rhamnose (rha), whose sequence in the ops was determined by noesy and hmbc experiments. the minor 3-o-acetylation (about 10%) of ... | 2011 | 21486667 |
| nodulation of thermopsis lupinoides by a mesorhizobium huakuii strain with a unique noda gene in kamtchatka, russia. | very little is known about rhizobia that form nodules on thermopsis spp. we report the isolation of a mesorhizobium huakuii strain with a unique noda gene that form nodules on thermopsis lupinoides in kamtchatka, russia. the isolate did not form nodules on thermopsis chinensis or thermopsis caroliniana, which suggests it may be host specific. | 2011 | 21652738 |
| studies on the biodegradation of fosfomycin: synthesis of 13c-labeled intermediates, feeding experiments with rhizobium huakuii pmy1, and isolation of labeled amino acids from cell mass by hplc. | racemic (1r*,2r*)-1,2-dihydroxy-[1-(13)c(1)]propylphosphonic acid and 1-hydroxy-[1-(13)c(1)]acetone were synthesized and fed to r. huakuii pmy1. alanine and a mixture of valine and methionine were isolated as their n-acetyl derivatives from the cell hydrolysate by reversed-phase hplc and analyzed by nmr spectroscopy. it was found that the carbon atoms of the respective carboxyl groups were highly (13)c-labeled (up to 65 %). hydroxyacetone is therefore considered an obligatory intermediate of the ... | 2011 | 22012897 |
| Identification of a novel gene for biosynthesis of a bacteroid-specific electron carrier menaquinone. | Ubiquinone (UQ) has been considered as an electron mediator in electron transfer that generates ATP in Rhizobium under both free-living and symbiosis conditions. When mutated, the dmtH gene has a symbiotic phenotype of forming ineffective nodules on Astragalus sinicus. The gene was isolated from a Mesorhizobium huakuii 7653R transposon-inserted mutant library. The DNA sequence and conserved protein domain analyses revealed that dmtH encodes demethylmenaquinone (DMK) methyltransferase, which cata ... | 2011 | 22194970 |
| elucidation of a novel lipid a α-(1,1)-gala transferase gene (rgtf) from mesorhizobium loti: heterologous expression of rgtf causes rhizobium etli to synthesize lipid a with α-(1,1)-gala. | an unusual α-(1,1)-galacturonic acid (gala) lipid a modification has been reported in the lipopolysaccharide of a number of interesting gram-negative bacteria, including the nitrogen-fixing bacteria azospirillum lipoferum, mesorhizobium huakuii and m. loti, the stalk-forming bacterium caulobacter crescentus and the hyperthermophilic bacterium aquifex aeolicus. however, the α-(1,1)-gala transferase (galat) gene, which we have named rgtf, was not identified. species of the rhizobium genera produce ... | 2013 | 23283001 |
| rna-seq and microarrays analyses reveal global differential transcriptomes of mesorhizobium huakuii 7653r between bacteroids and free-living cells. | mesorhizobium huakuii 7653r occurs either in nitrogen-fixing symbiosis with its host plant, astragalus sinicus, or free-living in the soil. the m. huakuii 7653r genome has recently been sequenced. to better understand the complex biochemical and developmental changes that occur in 7653r during bacteroid development, rna-seq and microarrays were used to investigate the differential transcriptomes of 7653r bacteroids and free-living cells. the two approaches identified several thousand differentia ... | 2014 | 24695521 |
| growth and survival of mesorhizobium loti inside acanthamoeba enhanced its ability to develop more nodules on lotus corniculatus. | the importance of protozoa as environmental reservoirs of pathogens is well recognized, while their impact on survival and symbiotic properties of rhizobia has not been explored. the possible survival of free-living rhizobia inside amoebae could influence bacterial abundance in the rhizosphere of legume plants and the nodulation competitiveness of microsymbionts. two well-characterized strains of mesorhizobium: mesorhizobium loti nzp2213 and mesorhizobium huakuii symbiovar loti maff303099 were a ... | 2015 | 25779926 |
| whole-genome sequencing of mesorhizobium huakuii 7653r provides molecular insights into host specificity and symbiosis island dynamics. | evidence based on genomic sequences is urgently needed to confirm the phylogenetic relationship between mesorhizobium strain maff303099 and m. huakuii. to define underlying causes for the rather striking difference in host specificity between m. huakuii strain 7653r and maff303099, several probable determinants also require comparison at the genomic level. an improved understanding of mobile genetic elements that can be integrated into the main chromosomes of mesorhizobium to form genomic island ... | 2014 | 24906389 |
| rhizobia with 16s rrna and nifh similar to mesorhizobium huakuii but novel reca, glnii, noda and nodc genes are symbionts of new zealand carmichaelinae. | new zealand became geographically isolated about 80 million years ago and this separation gave rise to a unique native flora including four genera of legume, carmichaelia, clianthus and montigena in the carmichaelinae clade, tribe galegeae, and sophora, tribe sophoreae, sub-family papilionoideae. ten bacterial strains isolated from nz carmichaelinae growing in natural ecosystems grouped close to the mesorhizobium huakuii type strain in relation to their 16s rrna and nifh gene sequences. however, ... | 2012 | 23118889 |
| bacteria of the genus roseobacter associated with the toxic dinoflagellate prorocentrum lima. | the dinoflagellate prorocentrum lima is known to produce diarrhetic shellfish poisons. however, it is yet unclear if the dinoflagellates themselves or the bacteria associated with them produce the toxins. here we analyze the toxicity as well as the spectrum of bacteria in two cultures of p. lima, namely p. lima-sy and p. lima-st, which initially derived from the same p. lima strain pl2v. toxicity tests, applying the artemia bioassay revealed in both cultures high levels of toxins. the bacteria, ... | 1998 | 23194717 |
| rhizobium strains differ considerably in outer membrane permeability and polymyxin b resistance. | six rhizobium (rhizobium leguminosarum bv. trifolii ta1, sinorhizobium meliloti 1021, mesorhizobium huakuii ifo 15243(t), ochrobactrum lupini lup 21(t), bradyrhizobium japonicum usda110 and b. elkanii usda 76) and two escherichia coli strains (e. coli atcc 25922 and e. coli hb 101) were compared in respect to polymyxin b and edta resistance, as well as bacterial outer membrane (om) permeability to a fluorescent hydrophobic agent (n-phenyl-1-naphthylamine - npn). tem (transmission electron micros ... | 2016 | 27253495 |
| mesorhizobium waimense sp. nov. isolated from sophora longicarinata root nodules and mesorhizobium cantuariense sp. nov. isolated from sophora microphylla root nodules. | in total 14 strains of gram-stain-negative, rod-shaped bacteria were isolated from sophora longicarinata and sophora microphylla root nodules and authenticated as rhizobia on these hosts. based on the 16s rrna gene phylogeny, they were shown to belong to the genus mesorhizobium, and the strains from s. longicarinata were most closely related to mesorhizobium amorphae accc 19665t (99.8–99.9 %), mesorhizobium huakuii iam 14158t (99.8–99.9 %), mesorhizobium loti usda 3471t (99.5–99.9 %) and mesorhi ... | 2015 | 26296780 |
| mesorhizobium shonense sp. nov., mesorhizobium hawassense sp. nov. and mesorhizobium abyssinicae sp. nov., isolated from root nodules of different agroforestry legume trees. | a total of 18 strains, representing members of the genus mesorhizobium, obtained from root nodules of woody legumes growing in ethiopia, have been previously shown, by multilocus sequence analysis (mlsa) of five housekeeping genes, to form three novel genospecies. in the present study, the phylogenetic relationship between representative strains of these three genospecies and the type strains of their closest phylogenetic neighbours mesorhizobium plurifarium, mesorhizobium amorphae, mesorhizobiu ... | 2013 | 22941297 |
| revision of the taxonomic status of type strains of mesorhizobium loti and reclassification of strain usda 3471t as the type strain of mesorhizobiumerdmanii sp. nov. and atcc 33669t as the type strain of mesorhizobiumjarvisii sp. nov. | the species mesorhizobim loti was isolated from nodules of lotus corniculatus and its type strain deposited in several collections. some of these type strains, such as those deposited in the usda and atcc collections before 1990, are not coincident with the original strain, nzp 2213t, deposited in the nzp culture collection. the analysis of the 16s rrna gene showed that strains usda 3471t and atcc 33669t formed independent branches from that occupied by mesorhizobium loti nzp 2213t and related t ... | 2015 | 25736411 |