| rhizobium tibeticum sp. nov., a symbiotic bacterium isolated from trigonella archiducis-nicolai (sirj.) vassilcz. | isolated from root nodules of trigonella archiducis-nicolai (sirj.) vassilcz. grown in tibet, china, cells of the bacterial strains ccbau 85039(t) and ccbau 85027 were gram-negative, aerobic, motile, non-spore-forming rods that formed colonies that were semi-translucent and opalescent on yeast extract-mannitol agar. in numerical taxonomy, sds-page analysis of whole-cell proteins and dna-dna hybridization, the two strains were very similar and were different from reference strains of defined rhiz ... | 2009 | 19643889 |
| [allelopathic effects of invasive weed solidago canadensis on native plants]. | with growth chamber method, this paper studied the allelopathic potential of invasive weed solidago canadensis on native plant species. different concentration s. canadensis root and rhizome extracts were examined, and the test plants were trifolium repens, trifolium pretense, medicago lupulina, lolium perenne, suaeda glauca, plantago virginica, kummerowia stipulacea, festuca arundinacea, ageratum conyzoides, portulaca oleracea, and amaranthus spinosus. the results showed that the allelopathic i ... | 2005 | 16515192 |
| stable low molecular weight rna profiling showed variations within sinorhizobium meliloti and sinorhizobium medicae nodulating different legumes from the alfalfa cross-inoculation group. | four different low molecular weight (lmw) rna profiles, designated i-iv, among 179 isolates from medicago, melilotus and trigonella species growing in a field site in northern spain were identified. from sequence analysis of the 16s rrna, atpd and reca genes as well as dna-dna hybridization analysis with representatives of each lmw rna profile it was evident that isolates with lmw rna profiles i and ii belonged to sinorhizobium meliloti and those displaying profiles iii and iv to sinorhizobium m ... | 2008 | 18399993 |
| characterization of symbiotic and endophytic bacteria isolated from root nodules of herbaceous legumes grown in qinghai-tibet plateau and in other zones of china. | qinghai-tibet plateau is the highest place in the world and the environment in that plateau is hard for animals and plants, with low temperature, low concentration of oxygen and high solar radiation. in this study, 61 root nodule isolates from vicia, oxytropis, medicago, melilotus and onobrychis species grown in qinghai-tibet plateau and in loess plateau were comparatively characterized. based upon the results of numerical taxonomy, ardra, aflp, dna-dna hybridization and 16s rdna sequencing, the ... | 2007 | 17541555 |
| characterization of rhizobia from ineffective alfalfa nodules: ability to nodulate bean plants [phaseolus vulgaris (l.) savi.]. | this study was initiated to characterize rhizobium isolates obtained from root nodules of ineffectively nodulated, field-grown alfalfa (medicago sativa l.) plants. the purpose was to determine if these isolates possessed characteristics which would explain either their ineffectiveness in n(2) fixation or their apparent ability to tolerate the moderately acid soil conditions from which they originated. isolates were characterized by analysis of growth rate, 39 degrees c tolerance, acid production ... | 1985 | 16346942 |
| [effects of simulated nitrogen deposition on weeds growth and nitrogen uptake]. | in this paper, a greenhouse experiment was conducted to study the responses of different functional groups weeds to simulated nitrogen deposition (4.0 g n.m(-2).yr(-1)). native weed species poa annua, lolium perenne, avena fatua, medicago lupulina, trifolium repens, plantago virginica, veronica didyma, echinochloa crusgalli var. mitis, eleusine indica and amaranthus spinosus in orchard ecosystem were used test materials, and their above-and underground biomass and nitrogen uptake were measured. ... | 2005 | 16110678 |
| the rhizobium meliloti region located downstream of the nod box n6 is involved in the specific nodulation of medicago lupulina. | six nod box regulatory sequences are present in the rhizobium meliloti genome. we have analysed the dna region located downstream of nod box n6, and identified three open reading frames, designated nolqa, nolqb and nols. lacz fusions in these orfs are not induced by classical nod gene inducers, which indicates that their expression either is not under the control of the nod box, or involves another regulatory mechanism acting in conjunction with the nodd/nod box regulatory circuit. mutations in ... | 1995 | 8522144 |
| cryptic viruses in hop trefoil (medicago lupulina) and their relationships to other cryptic viruses in legumes. | three double-stranded (ds) rna-containing viruses, named hop trefoil cryptic virus (htcv) 1, 2 and 3, were found in apparently healthy seedlings of hop trefoil (medicago lupulina). only 1-2% of plants tested were virus-free. the particles occurred in the cytoplasm, nuclei and nucleoli of parenchyma cells. they were purified as a mixture (htcv-m) with a mean yield of 50-100 micrograms/kg fresh tissue, and an antiserum was obtained. htcv1 was serologically related to one component (acv1) of a mixt ... | 1987 | 3450677 |
| short-term variability of plant populations within a regularly disturbed habitat. | the changing populations of weeds during 13 years of the broadbalk continuous wheat experiment were analysed to investigate the extent of differences in shortterm variability of cover between species. the data were from two sections of the experiment where winter wheat was grown continuously under herbicide treatment for 13 and 6 years respectively. logistic regressions were fitted to the data. equisetum arvense showed significant long-term increases on both sections; long-term trends were also ... | 1993 | 28313670 |
| rhizobial symbiosis effect on the growth, metal uptake, and antioxidant responses of medicago lupulina under copper stress. | the effects of rhizobial symbiosis on the growth, metal uptake, and antioxidant responses of medicago lupulina in the presence of 200 mg kg(-1) cu(2+) throughout different stages of symbiosis development were studied. the symbiosis with sinorhizobium meliloti ccnwsx0020 induced an increase in plant growth and nitrogen content irrespective of the presence of cu(2+). the total amount of cu uptake of inoculated plants significantly increased by 34.0 and 120.4% in shoots and roots, respectively, com ... | 2015 | 25903186 |
| an omp gene enhances cell tolerance of cu(ii) in sinorhizobium meliloti ccnwsx0020. | the main aim of this work was to study molecular characterization of a dna fragment conferring resistance to cu(ii) in sinorhizobium meliloti ccnwsx0020. the strain ccnwsx0020, resistant to 1.4 mmol l(-1) cu(ii) in tryptone-yeast extract medium was isolated from medicago lupulina growing in mine tailings of fengxian county, china. the availability of the complete genome sequence of s. meliloti ccnwsx0020 provides an opportunity for investigating genes that play significant roles in cu(ii) resist ... | 2013 | 23526229 |
| proposal of ensifer psoraleae sp. nov., ensifer sesbaniae sp. nov., ensifer morelense comb. nov. and ensifer americanum comb. nov. | in a survey of rhizobia associated with the native legumes in yunnan province, china, seven and nine strains isolated from the root nodules of psoralea corylifolia, sesbania cannabina and medicago lupulina were respectively classified into the novel genomic species groups i and ii in the genus ensifer (former sinorhizobium) based on the sequence analyses of the 16s rrna gene. analyses of concatenated housekeeping genes (atpd, reca and glnii) further revealed that they were distinct lineages in t ... | 2013 | 23759600 |
| standing genetic variation in host preference for mutualist microbial symbionts. | many models of mutualisms show that mutualisms are unstable if hosts lack mechanisms enabling preferential associations with mutualistic symbiotic partners over exploitative partners. despite the theoretical importance of mutualism-stabilizing mechanisms, we have little empirical evidence to infer their evolutionary dynamics in response to exploitation by non-beneficial partners. using a model mutualism-the interaction between legumes and nitrogen-fixing soil symbionts-we tested for quantitative ... | 2014 | 25355477 |
| draft genome sequence of sinorhizobium meliloti ccnwsx0020, a nitrogen-fixing symbiont with copper tolerance capability isolated from lead-zinc mine tailings. | sinorhizobium meliloti ccnwsx0020 was isolated from medicago lupulina plants growing in lead-zinc mine tailings, which can establish a symbiotic relationship with medicago species. also, the genome of this bacterium contains a number of protein-coding sequences related to metal tolerance. we anticipate that the genomic sequence provides valuable information to explore environmental bioremediation. | 2012 | 22328762 |
| genes conferring copper resistance in sinorhizobium meliloti ccnwsx0020 also promote the growth of medicago lupulina in copper-contaminated soil. | sinorhizobium meliloti ccnwsx0020, isolated from root nodules of medicago lupulina growing in gold mine tailings in the northwest of china, displayed both copper resistance and growth promotion of leguminous plants in copper-contaminated soil. nevertheless, the genetic and biochemical mechanisms responsible for copper resistance in s. meliloti ccnwsx0020 remained uncharacterized. to investigate genes involved in copper resistance, an s. meliloti ccnwsx0020 tn5 insertion library of 14,000 mutants ... | 2014 | 24441157 |
| population genomics of sinorhizobium medicae based on low-coverage sequencing of sympatric isolates. | we investigated the genomic diversity of a local population of the symbiotic bacterium sinorhizobium medicae, isolated from the roots of wild medicago lupulina plants, in order to assess genomic diversity, to identify genomic regions influenced by duplication, deletion or strong selection, and to explore the composition of the pan-genome. partial genome sequences of 12 isolates were obtained by roche 454 shotgun sequencing (average 5.3 mb per isolate) and compared with the published sequence of ... | 2011 | 21562597 |
| characterization of a copper-resistant symbiotic bacterium isolated from medicago lupulina growing in mine tailings. | a root nodule bacterium, sinorhizobium meliloti ccnwsx0020, resistant to 1.4 mm cu2+ was isolated from medicago lupulina growing in mine tailings. in medium supplied with copper, this bacterium showed cell deformation and aggregation due to precipitation of copper on the cell surface. genes similar to the copper-resistant genes, pcor and pcoa from escherichia coli, were amplified by pcr from a 1.4-mb megaplasmid. inoculation with s. meliloti ccnwsx0020 increased the biomass of m. lupulina grown ... | 2011 | 20843682 |
| ensifer, phyllobacterium and rhizobium species occupy nodules of medicago sativa (alfalfa) and melilotus alba (sweet clover) grown at a canadian site without a history of cultivation. | phage-resistant and -susceptible bacteria from nodules of alfalfa and sweet clover, grown at a site without a known history of cultivation, were identified as diverse genotypes of ensifer, rhizobium and phyllobacterium species based on sequence analysis of ribosomal (16s and 23s rrna) and protein-encoding (atpd and reca) genes, southern hybridization/rflp and a range of phenotypic characteristics. among phage-resistant bacteria, one genotype of rhizobium sp. predominated on alfalfa (frequency ap ... | 2010 | 19875436 |
| [soil infiltration capacity under different vegetations in southern ningxia loess hilly region]. | a new apparatus for measuring the run off-on-out under simulated rainfall conditions was used to study the soil infiltration capacity under different rainfall intensities and vegetations in loess hilly region of southern ningxia, with the relationships between soil water-stable aggregate content and soil stable infiltration rate under different vegetations analyzed. the results showed that the regression equations between rainfall duration and soil infiltration rate under different vegetations a ... | 2008 | 18655590 |