| nitrogen fixation (nif) genes and large plasmids of rhizobium japonicum. | the location of structural nitrogen-fixation genes was determined for the slow- and fast-growing types of rhizobium japonicum. slow-growing r. japonicum strains do not harbor structural nif genes, homologous to nifd and nifh, on large plasmids (100 to 200 megadaltons). in contrast, all fast-growing r. japonicum strains, except prc194, contain structural nif genes on large plasmids. | 1982 | 7130134 |
| identification of structural proteins of rhizobium meliloti temperate phage 16-3. | the structural proteins of rhizobium meliloti temperate phage 16-3 have been analysed by means of polyacrylamide gel electrophoresis, isoelectric focusing and agarose gel electrophoresis. five major and five minor proteins were identified and characterized with respect to their size, isoelectric point and their distribution between the head ad tail of the phage particle. the synthesis of structural proteins was studied by one- and two-dimensional gel electrophoresis. | 1982 | 7130949 |
| passage of bacterial dna into host cells during in vitro transformation of nicotiana tabacum by agrobacterium tumefaciens. | tumorigenic and non-tumorigenic strains of agrobacterium tumefaciens were labelled with tritiated thymidine and added separately to suspension cultures of x-d line habituated tobacco cells. the subsequent association of bacteria with plant host cells and the passage of bacteria and bacterial dna into these cells was examined by conventional light and electron microscopy and light microscope autoradiography. the results suggest that both strains of bacterium enter damaged host cells (via wall les ... | 1982 | 7144594 |
| identification of the sym plasmid of rhizobium leguminosarum strain 1001 and its transfer to and expression in other rhizobia and agrobacterium tumefaciens. | | 1982 | 7146147 |
| dna from the a6s/2 crown gall tumor contains scrambled ti-plasmid sequences near its junctions with plant dna. | the a6s/2 tumor incited on tobacco by agrobacterium tumefaciens harboring the octopine-type a6 ti plasmid contains one insert of ti-plasmid sequences (the t dna). this 13 kb insert is derived from a colinear sequence in the ti plasmid (the t region) and becomes attached to plant dna in the nucleus of the host cell. we have determined the dna sequence encompassing the left end of the t region of the a6 ti plasmid and the corresponding portion of the a6s/2 t dna. the two sequences are identical fo ... | 1982 | 7151163 |
| nucleotide sequence and transcript map of the agrobacterium tumefaciens ti plasmid-encoded octopine synthase gene. | we have determined the complete nucleotide sequence of the gene for the crown gall enzyme, octopine synthase. the sequence was derived from cloned fragments of the agrobacterium tumefaciens ti plasmid ach5. it displayed a continuous open reading frame encoding a polypeptide chain of 358 amino acids. the nucleotide positions corresponding to the 5' end and poly(a) addition site of the mature octopine synthase mrna from a tobacco tumor cell line were determined by s1 nuclease mapping. two sequence ... | 1982 | 7153687 |
| multiple transcripts of t-dna detected in nopaline crown gall tumors. | crown gall plant tumors contain neoplastic cells transformed by incorporation of a foreign dna element, t-dna, derived from a large tumor-inducing plasmid in the inciting agrobacterium strain. t-dna is covalently joined to the nuclear dna of the tumor cell, and rna transcripts from t-dna are present in polyadenylated form on polysomes. this paper presents a detailed analysis of those parts of t-dna transcribed in a nopaline-type tobacco teratoma, bt37, whose t-dna has been mapped and cloned. nor ... | 1982 | 7153688 |
| nopaline synthase: transcript mapping and dna sequence. | the dna sequence of the nopaline synthase gene (nos) from agrobacterium tumefaciens ti plasmid ptit37 and adjacent regions up to the right border of the t-dna was determined. the 5' and 3' termini of the polyadenylated nos mrna, isolated from a t37 tobacco teratoma tumor line, were localized by s1 mapping. the final mrna is unspliced, encoded by a region of about 1450 bp, and specifies an open reading frame of 413 amino acids. potential transcriptional signals in the 5' flanking dna, such as cat ... | 1982 | 7153689 |
| [preliminary trial of the cultivation of winged beans (psophocarpus tetragonolobus) in guatemala and variations in their chemical composition]. | there is no reliable information concerning the cultivation practices of winged bean cultivars in the area; therefore, it was considered of interest to participate in the first international winged bean trial, which was peformed according to a standardized procedure. the planting site was located at 90 degrees longitude and 15 degrees latitude, and 250 meters above sea level, in a hot-humid environment. sowing was performed in the middle of november, under continuous irrigation until april. duri ... | 1982 | 7181624 |
| coated and smooth vesicles in the biogenesis of cell walls, plasma membranes, infection threads and peribacteroid membranes in root hairs and nodules of white clover. | | 1982 | 7183700 |
| lectins and the soybean-rhizobium symbiosis. i. immunological investigations of soybean lines, the seeds of which have been reported to lack the 120 000 dalton soybean lectin. | seeds of six soybean lines (glycine max (l.) merr. cv. columbia, d68-127, norredo, sooty, t-102, wilson 5) have been reported to lack the 120 000 dalton soybean lectin. immunodiffusion and radioimmunoassay using anti-soybean lectin immunoglobulin failed to detect the lectin in seeds of five lines, but d68-127 seeds contained as much soybean lectin as the control line, harosoy 63. the d68-127 seed lectin could be purified by affinity chromatography on sepharose-n-caproylgalactosamine, and was ind ... | 1980 | 7190028 |
| differentiation of rhizobium japonicum strain derivatives by antibiotic sensitivity patterns, lectin binding, and utilization of biochemicals. | several strains of rhizobium japonicum have been reported to consist of mixtures of stable derivativess having distinct colony morphologies and physiological characteristics. we isolated derivatives from strains of r. japonicum and systematically compared them with previously isolated derivatives with respect to the utilization of biochemicals, antibiotic sensitivity, and soyben lectin binding. with the exception of a pair of derivatives from 3ilb110, one of which utilized pyruvate and one of wh ... | 1980 | 7190460 |
| nodulation of soybeans carrying the nodulation-restrictive gene, rj1, by an incompatible rhizobium japonicum strain upon mixed inoculation with a compatible strain. | the rj1 gene in soybeans prevents nodulation by most strains of rhizobium japonicum. several strains, however, are known to nodulate rj1 plants in vermiculite or sand culture. pure broth cultures of one of these strains (61 nalr) and a strain producing the typical non-nodulating response with rj1 (i-110 ars) were mixed and used as inoculum on clark rj1 soybeans in a growth chamber experiment. both strains carried drug resistance markers and were identified using selective media. analysis of the ... | 1980 | 7190864 |
| free-living and symbiotic characteristics of chlorate resistant mutants of rhizobium. | this work investigated the usefulness of chlorate resistance as a method for the selection of nitrate reductase negative (nr-) strains from rhizobium japonicum (61a76) and evaluated the symbiotic, characteristics of these strains. chlorate resistent strains were selected from populations seeded on cs 7 agar containing 10 or 20 mm kc10, and incubated in 2% air- 98% n2-co2 (95:5). over 200 resistant strains were isolated, 58% of which lacked the dissimilatory nitrate reductase. in 12 selected isol ... | 1980 | 7190866 |
| changes in the outer cell wall of rhizobium during development of root nodule symbiosis in soybean. | treatment of soybean root nodule tissue with a nonionic detergent. nonidet p-40, after aldehyde fixation, results in a selective solubilization of membranes. the cell wall membrane of bacteroids and of free-living rhizobium is resistant to this treatment. fragments of "extra" membrane present inside the membrane envelope enclosing the bacteroids are also resistant to the detergent and are morphologically similar to the outer membrane of the cell wall of rhizobium grown in broth culture. these ob ... | 1980 | 7193073 |
| localization and partial characterization of soybean lectin-binding polysaccharide of rhizobium japonicum. | immunoelectron microscopy was combined with partial characterization of isolated exopolysaccharide to study binding of soybean lectin by rhizobium japonicum strain usda 138. lectin-binding activity resided in two forms of exopolysaccharide produced during growth: an apparently very high-molecular-weight capsular form and a lower-molecular-weight diffusible form. at low-speed centrifugation, the capsular form cosedimented with cells to form a viscous, white, cell-gel complex which was not diffusi ... | 1981 | 7193204 |
| nitrogen fixation by nitrate reductase deficient mutants of rhizobium japonicum. | | 1980 | 7194311 |
| induction and expression of nodule-specific host genes in effective and ineffective root nodules of soybean. | | 1981 | 7194687 |
| regulation of the expression of leghaemoglobin genes in effective and ineffective root nodules of soybean. | the expression of leghaemoglobin genes in effective and ineffective (unable to fix nitrogen) root nodules of soybean developed by rhizobium japonicum strains 61a76, 61a24 and sm5 was measured by using a cdna probe or a cloned leghaemoglobin sequence and in vitro translation of lb-mrna. hybridization of the poly(a)-containing nodule polysomal rna from 3-week-old nodules with a kinetically purified lb-cdna or with plasmid (plbl) containing a leghaemoglobin sequence showed that lb-mrna is present i ... | 1981 | 7194688 |
| interaction of lectins from soybean and peanut with rhizobia that nodulate soybean, peanut, or both plants. | four of 14 strains of rhizobium japonicum from soybean nodulated peanut (arachis hypogaea l. cultivar jumbo virginia), and 3 of 8 rhizobium sp. strains from peanut nodulate soybean (glycine max (l.) merr. cultivar harosoy 63). cells of three peanut rhizobia bound fluorescent- and radioisotope-labeled soybean lectin. two of these strains failed to nodulate soybean, and conversely, two peanut strains that nodulated soybean did not bind to soybean lectin. both culture medium and age had pronounced ... | 1980 | 7195297 |
| the isolation and characterization of a root lectin from soybean (glycine max (l), cultivar chippewa). | a lectin has been isolated from the roots of 5-day soybean (glycine max (l) cultivar chippewa) seedlings, and its properties have been compared to those of the soybean seed lectin. the sugar-binding activities of the two lectins, both in terms of specific hemagglutinating activity and sugar specificity, are indistinguishable. molecular properties of the two lectins, measured as relative molecular weights, isoelectric and electrophoretic patterns, amino acid compositions, immunochemical cross-rea ... | 1981 | 7198118 |
| application of two new methods for cleavage of polysaccharides into specific oligosaccharide fragments. structure of the capsular and extracellular polysaccharides of rhizobium japonicum that bind soybean lectin. | the extracellular polysaccharide produced by the bacterium rhizobium japonicum has been implicated in the recognition between symbionts which takes place in the association of r. japonicum with soybean. the complete primary structure of the polysaccharide produced by r. japonicum strain 3i1b 138 has been determined by a combination of conventional and unconventional methods. the polymer contains glucose, mannose, and galacturonic acid in the molar ratio of 2:1:1 and contains a varying proportion ... | 1982 | 7199046 |
| the odd couple. | | 1982 | 7201965 |
| soluble aldehyde dehydrogenase and metabolism of aldehydes by soybean bacteroids. | a soluble aldehyde dehydrogenase (ec 1.2.1.3) was partially purified from rhizobium japonicum bacteroids and from free-living r. japonicum 61a76. the enzyme was activated by nad+, nadh, and dithiothreitol, and it reduced nad(p)+. acetaldehyde, propionaldehyde, butyraldehyde, benzaldehyde, and succinic semialdehyde were substrates. the km for straight-chain aldehydes decreased with increasing carbon chain length. the aldehyde dehydrogenase was inhibited by 6-cyanopurine, but not by metronidazole. ... | 1982 | 7202001 |
| light and electron microscopic studies of nodule structure of alfalfa. | light and electron microscopy was used to establish the structural organisation of the developing nodule of alfalfa. in these nodules three distinct regions were noted: (1) the base region, site of original infection where the nodule is attached to the root and now composed of degenerating nodule tissue, (2) the central region, or active region composed of nodule cells containing tightly packed bacteroids surrounding a central vacuole, and (3) the meristematic region, a site of new growth, behin ... | 1981 | 7214231 |
| [bacterial population dynamics in a soil--plant system]. | the dynamics of rhizobium leguminosarum and arthrobacter crystallopoietes populations introduced into soil at different levels of density was studied in a zone near barley roots. microbial life with a high rate of growth was found only at the root surface. for a. crystallopoietes, the ultimate bacterial incidence at the root surface was found to depend on the original level of population density. for rh. leguminosarum, the ultimate incidence was shown to reach an identical level irrespective of ... | 1981 | 7219211 |
| [relationship between the dynamics of the numbers of nodule bacteria in the soil and the stage of microbial succession]. | the survival of a population of nodule bacteria after its introduction into soil depends on the ratio between favourable and unfavourable microzones. this ratio does not remain constant in one and the same soil at different stages of microbial succession even if the succession is caused by simple humidification of the soil without any introduction of additional substrates. the dynamics of the incidence of nodule bacteria introduced, at one and the same level, into soil samples of different growt ... | 1981 | 7219215 |
| isolation & characterization of antibiotic resistant mutants of cowpea rhizobium 32hi. | | 1980 | 7228122 |
| a method to determine protein of bacteria grown in agar. | a method is described to determine the amount of protein of bacteria grown in agar. amino acid contents of hydrolysates of agar cultures are compared with the amino acids in hydrolysates of the same bacteria grown in a liquid medium. in the latter medium also the amount of bacterial protein is determined. from these data the protein content of bacteria grown in agar can be calculated. | 1980 | 7235686 |
| [glucose metabolism in isolated bacteroids of lupine nodules]. | the ability of the bacteroids rhizobium lupini isolated from the nodules at the stage of active nitrogen fixation to consume [1-14c]- and [2-14c] glucose was studied. 5 min after glucose addition to the cell suspension the label is rapidly incorporated into the organic acids, amino acids and sugars, which is indicative of glucose penetration inside the bacteroids and of a high rate of its catabolism. the rapid incorporation of the label into all krebs cycle metabolites and the activities of citr ... | 1980 | 7248347 |
| retention of tumor markers in f1 progeny plants from in vitro induced octopine and nopaline tumor tissues. | tumorous tobacco shoots have been derived from callus tissues produced by agrobacterium tumefaciens--induced transformation of tobacco protoplasts and by fusion of normal protoplasts with those from crown gall tumors. the continued presence of t-dna sequences in shoots is directly demonstrated by southern blotting and is also revealed by the presence of the tumor markers octopine and nopaline. when grafted onto normal tobacco plants, both octopine- and nopaline-type shoots (including those from ... | 1981 | 7249079 |
| [biological properties of agrobacterium tumefaciens rna-polymerase. i. isolation of rna-polymerase from agrobacterium tumefaciens 8628]. | rna-polymerase is isolated from agrobacterium tumefaciens 8628. when fractioning the protein extract by deae-cellulose, rna-polymerase is separated into three fractions eluated with 0.15, 0.165, and 0.185 m kci. their electrophoresis in polyacrylamide gel shows that the composition of subunits in the second and third fractions is, in principle, similar to that of escherichia coli rna-polymerase, but the first fraction protein distribution pattern differs from he mentioned fractions. the data obt ... | 1980 | 7256932 |
| correlation between map position and phenotype of cti mutants in the c cistron of rhizobium meliloti phage 16-3. | nine temperature-sensitive clear mutations (cti) in the c cistron (coding for the repressor protein) of rhizobium meliloti temperate phage 16-3 were characterized according to the inductive temperature, the immunity of cells lysogenic for these mutant phages to superinfection by homoimmune weak virulent mutants, the phenotype of double-ti mutants and interallelic complementation. the results indicate that mutations of similar phenotypic expression are clustered on the genetic map. furthermore, i ... | 1980 | 7262538 |
| cell surface carbohydrates of agrobacterium tumefaciens involved in adherence during crown gall tumor initiation. | | 1981 | 7271806 |
| [microstructure of pea nodules infected with a neomycin-resistant mutant of nodule bacteria]. | the neomycin-resistance mutation of pea nodule bacteria does not interfere with the formation of infection threads when the bacterium inoculates the host plant, or with the axial differentiation of the nodular tissue. at the same time, intracellular neomycin-resistant nodule bacteria do not acquire the bacteroid structure. once the bacterium is incorporated into the cytoplasm of the host cell, it loses the peribacteroid membrane and undergoes lysis. therefore, the neomycin-resistant pea nodule b ... | 1981 | 7278721 |
| transcription of the agrobacterium ti plasmid in the bacterium and in crown gall tumors. | | 1981 | 7280084 |
| nonmutagenic activity of the nitroprusside. | the mutagenic activity of the pentacyanonitrosylferrate (ii) (np) was studied by the prophage induction and the drosophila mosaic test. on the basis of plaque and mosaic spot induction freqauencies it is concluded that both np and its adenine complex are nonmutagenic as for induction of chromosome breaks and point mutations. the nonmutagenic activity of the np can be attributed to its nonpermeability through cell membranes. | 1981 | 7282210 |
| succinate transport in rhizobium leguminosarum. | the transport of succinate was studied in an effective streptomycin-resistant strain of rhizobium leguminosarum. high levels of succinate transport occurred when cells were grown on succinate, fumarate, or malate, whereas low activity was found when cells were grown on glucose, sucrose, arabinose, or pyruvate as the sole carbon source. because of the rapid metabolism of succinate after transport into the cells, a succinate dehydrogenase-deficient mutant was isolated in which intracellular succin ... | 1981 | 7287623 |
| [inoculation of rhizobium phaseoli onto different species of the genus phaseolus originating in mexico]. | | 1980 | 7291776 |
| the amino acid composition of rhizobium meliloti flagellin: occurrence of a single tryptophan residue. | | 1981 | 7295319 |
| genetic transformation of rhizobium meliloti by plasmid dna. | a procedure for the genetic transformation of rhizobium meliloti by plasmid dna is described. it is an adaptation of a procedure used originally for escherichia coli and later for agrobacterium tumefaciens. depending on the r. meliloti isolate used as the recipient, the efficiency of transformation was in the range of 7 x 10(1) to 3.7 x 10(3) per microgram of plasmid prk248 dna and 10(-6) to 10(-9) per viable cell. a number of different naturally occurring strains could be transformed. plasmids ... | 1981 | 7297855 |
| competitive advantage provided by bacterial motility in the formation of nodules by rhizobium meliloti. | the effect of motility on the competitive success of rhizobium meliloti in nodule production was investigated. a motile strain formed more nodules than expected when mixed at various unfavorable ratios with either flagellated or nonflagellated nonmotile derivatives. we conclude that motility confers a selective advantage on rhizobia when competing with nonmotile strains. | 1981 | 7298580 |
| bacterial attachment as related to cellular recognition in the rhizobium-legume symbiosis. | bacterial attachment is viewed as a cellular recognition event during the infection of legumes by the nitrogen-fixing symbiont, rhizobium. studies on the biochemical basis of selective attachment are reviewed, and suggest that this recognition process is accomplished by specific glycoprotein lectin-polysaccharide interactions on the surfaces of the symbionts. an understanding of host specificity may lead to ways to broaden the host range of nitrogen-fixing symbioses. | 1981 | 7299839 |
| distribution of cytokinin-active nucleosides in isoaccepting transfer ribonucleic acids from agrobacterium tumefaciens. | the cytokinin-active isoprenoid nucleosides of agrobacterium tumefaciens transfer ribonucleic acid were identified by high-pressure liquid chromatography, permethylation, and mass spectroscopy. besides the expected 6-[(3-methylbut-2-enyl)amino]-9-(beta-d-ribofuranosyl)purine (i6a) and its 2-methylthio derivative (ms2i6a), substantial amounts of cis- and trans-ribosylzeatin (io6a) and cis-2-(methylthio)ribosylzeatin (c-ms2io6a) were present. these hydroxylated side chain derivatives are normally ... | 1981 | 7306490 |
| agrobacterium tumefaciens rna polymerase: a new purification procedure and a study of the stable binding sites on homologous deoxyribonucleic acid. | rna polymerase (rna nucleotidyltransferase, ec 2.7.7.6) of agrobacterium tumefaciens has been purified according to a fast and efficient procedure. the method involves only two chromatographic steps and yields a highly active enzyme. the rna polymerase was studied with respect to the ability to bind its homologous genome. a. tumefaciens deoxyribonucleic acid (dna) binds the enzyme even when fragmented at undergenic size (300 base pairs). the general binding is unspecific and very labile at low c ... | 1981 | 7306497 |
| cellular glycogen, beta-1,2,-glucan, poly beta-hydroxybutyric acid and extracellular polysaccharides in fast-growing species of rhizobium. | synthesis of acidic exopolysaccharides, neutral cellular polysaccharides and poly-beta-hydroxybutyric acid (phb) by rhizobium is strongly dependent on cultural conditions and the strains used. exopolysaccharide production by r. leguminosarum, r. phaseoli and r. trifolii closely parallels growth, whereas r. meliloti mainly excretes (low mol wt) polysaccharides when cell propagation is limited by lack of a necessary growth element (nitrogen) and an excess of carbon source is still present in the m ... | 1981 | 7337433 |
| transposition of tn904 encoding streptomycin resistance into the octopine ti plasmid of agrobacterium tumefaciens. | a transfer-deficient derivative of plasmid rp1-pmg1 was isolated after insertion of mu cts62. the tra- r plasmid was used to donate tn904, encoding streptomycin resistance, to ti plasmid pal102 harbored by agrobacterium tumefaciens ach5. under conditions promoting high ti transfer frequencies, 155 strains were isolated in which the streptomycin marker coupled with ti plasmid in further transfer experiments. these isolates represent stable insertions of tn904 into the ti plasmid. in addition, 19 ... | 1980 | 7353997 |
| occurrence and levels of cis-and trans-zeatin ribosides in the culture medium of a virulent strain of agrobacterium tumefaciens. | | 1980 | 7358157 |
| integration and organization of ti plasmid sequences in crown gall tumors. | the ti plasmid sequences (t dna) maintained in four unorganized crown gall tumor lines were defined by using restriction endonucleases and molecular hybridization techniques. each tumor line contains a "core" t dna which is apparently responsible for maintaining the transformed state; the core t dna is colinear with the ti plasmid and contains the ti plasmid sequences referred to as the "common dna"--sequences found in all ti plasmids studied to date. a given ti plasmid does not always give rise ... | 1980 | 7363328 |
| behavioral mutants of rhizobium meliloti. | rhizobium meliloti exhibited behavior resembling that of other chemotactic bacteria. nonflagellated, nonmotile but flagellated, and nonchemotactic mutants were isolated, and genetic mapping placed all three types of lesions within a small region of the r. meliloti chromosome. results from nodulation experiments performed with these mutants indicate that members of the three classes (fla-, mot-, and che-) infect and produce as many nodules on alfalfa plants as does the wild-type strain. | 1980 | 7364717 |
| infection and nodulation of clover by nonmotile rhizobium trifolii. | nonmotile mutants of rhizobium trifolii were isolated to determine whether bacterial motility is required for the infection and nodulation of clover. the nonmotile mutants were screened for their ability to infect and nodulate clover seedlings in fahraeus glass slide assemblies, plastic growth pouches, and vermiculite-sand-filled clay pots. in each system, the nonmotile mutants were able to infect and nodulate clover. | 1980 | 7364722 |
| diversity among b6 strains of agrobacterium tumefaciens. | a total of 20 laboratory substrains of agrobacterium tumefaciens strain b6 were compared with respect to six characteristics, including 3-ketolactose production, lysogeny, octopine catabolism, tumorigenic host range, and plasmid content. within this group of strains diversity was found for all characteristics except 3-ketolactose production. six substrains were lysogenized with an omega-type phage, whereas one substrain appeared neither sensitive to nor lysogenized with this bacteriophage. all b ... | 1980 | 7364725 |
| rhizobium leguminosarum mutants incapable of normal extracellular polysaccharide production. | mutants of rhizobium leguminosarum which are deficient in normal polysaccharide production have been isolated and characterized. a correlation between diminished production of extracellular polysaccharide and reduced infection and nodulation efficiency has been observed. | 1980 | 7364730 |
| beta-2-linked glucans secreted by fast-growing species of rhizobium. | fast-growing species of rhizobium were found to secrete low-molecular-weight beta-2-linked glucans when cultured in synthetic liquid medium. these glucans are quite similar to beta-2-linked glucans produced by species of agrobacterium. no reducing terminus was detected in these glucans. | 1980 | 7372570 |
| morphology and general characteristics of viruses active against cowpea rhizobium cb756 and 32h1. | two newly isolated viruses, rs1 and rs2, infective on two strains of cowpea rhizobium capable of n2-fixation in vitro, were characterized. rs1 parasitizes cb756 but rs2 infects both 32h1 and cb756. rs1 has an isometric, polyhedral head and a long contractile tail, while rs2 has an oblate, polyhedral head and a long flexible non-contractile tail; rs1 is considerably larger than rs2. the phages were relatively stable between ph 5 and 9 (1 hour incubation). rs1 appeared to be more thermal sensitive ... | 1980 | 7377972 |
| sensitivity of rhizobium to selected isoflavonoids. | eleven isoflavonoids were tested in both soft agar and liquid media for inhibitory activity against eight rhizobium strains. results of the two bioassays showed that pisatin, coumestriol, biochanin a, formononetin, genistein, rotenon, and vestitol lacked significant inhibitory activity. phaseolin and maackiain were moderately inhibitory (ed50 (mean effective dose) = 30-100 microgram/ml), and medicarpin and kievitone were strongly inhibitory (ed50 = 10-60 microgram/ml) towards slow-growing r. jap ... | 1980 | 7378947 |
| dynamics of rhizobium competition for nodulation of pisum sativum cv. afghanistan. | nodulation of pisum sativum cv. afghanistan by rhizobium leguminosarum strain tom can be blocked by the nonnodulating r. leguminosarum strain pf2. this system was used to study the dynamics of rhizobial binding to seedling root surfaces. appreciable numbers of 35s-labeled rhizobia bound to the root surface within 2h after inoculation. pf2 colonized the root surfaces earlier and in greater numbers that did tom. radioactive extracellular polysaccharides and lipopolysaccharides from either organism ... | 1980 | 7378950 |
| energy requirement for nitrogen fixation in actinorhizal and legume root nodules. | the ratio of respiration to nitrogenase activity was measured in five species of actinorhizal root nodules and eight species of legume nodules. the two types of nodules could not be distinguished on the basis of this ratio; this evidence thus indicates that the energy cost of nitrogen fixation is similar for both. | 1980 | 7384801 |
| cytokinins in tobacco crown gall tumors. | | 1980 | 7387655 |
| identification of "nodule-specific" host proteins (nodoulins) involved in the development of rhizobium-legume symbiosis. | infection of legume roots with rhizobium species results in the development of a root nodule structure in which the bacteria form an intracellular symbiosis with the plant. we report here that the infection of soybean (glycine max l.) roots with rhizobium japonicum results in the synthesis by the plant of at least 18-20 polypeptides other than leghemoglobin during the development of root nodules. identification of these "nodule-specific" host polypeptides (referred to as nodulins) was accomplish ... | 1980 | 7388942 |
| the effect of rhizobiophages on populations of rhizobium trifolii in the root zone of clover plants. | the effect of rhizobiophages ct3 and ct4 on rhizobium trifolii su91 and su36, respectively, was examined. these phage-susceptible strains were used, either singly or paired with a competing phage-resistant type as inoculum for trifolium subterraneum plants growing in vitro in agar medium. addition of bacteriophage to single strain experiments produced no significant effects on total bacterial numbers, nodulation, or plant dry weight. however, when phages were added to the paired inocula, signifi ... | 1980 | 7397602 |
| fractionation and characterization of two morphologically distinct types of cells in rhizobium japonicum broth culture. | differential centrifugation of stationary phase broth culture of rhizobium japonicum yielded two distinct morphological types of bacterial cells, rods, and small coccoid forms with capsulated and non-capsulated cells in each group. the rods usually had polar capsules which resulted in "star" formation. the coccoid bacteria were either free with thick capsular material surrounding the cells or held together in a common capsular sheath forming clusters and chains. 125i soybean. lectin bound to the ... | 1980 | 7407699 |
| interactions between octopine and nopaline plasmids in agrobacterium tumefaciens. | transfer of octopine ti plasmids to strains already carrying an octopine ti plasmid was found to occur at the same (high) frequency as transfer to ti plasmid lacking recipients, showing that resident ti plasmids do not exhibit entry exclusion towards incoming ti plasmids. the resident octopine ti plasmid was lost by the recipient after the entrance of the incoming ti plasmid, which is indicative of the incompatibility between the ti plasmids. octopine ti plasmids were found to become established ... | 1980 | 7410319 |
| developmental fate of rhizobium meliloti bacteroids in alfalfa nodules. | nitrogen-fixing bacteroids are degraded during nodule senescence. this is in contrast to recent implications that viable bacteroids can be released into soil from legume nodules. rhizobia originating from persistent infection threads in senescing nodule plant cells seem to be the source of viable cells required for perpetuation of the rhizobium spp. population in the soil. our conclusions were derived from electron microscopic examination of stages of development and senescence of alfalfa root n ... | 1980 | 7410321 |
| [preservation of lyophilized cultures of saprophytic microorganisms]. | all of the tested saprophytic microbial cultures remained viable upon 11--16 years of storage in the lyophilized state at 3--6 degrees. the cultures belonged to the following taxonomic groups: acetobacter, achromobacter, azotobacter, bacillus, chromatium, escherichia, flavobacterium, lactobacillus, micrococcus, proteus, propionibacterium, pseudomonas, rhizobium, sarcina, serratia, streptococcus, torula, mycobacterium, actinomyces. the number of viable cells in the tubes decredased only slightly ... | 1980 | 7412623 |
| specific adsorption of bacteria to clover root hairs, related to the presence of the plasmid pwz2 in cells of rhizobium trifolii. | rhizobium trifolii strains containing plasmid pwz2, the genetic element indispensable for nodule induction, showed a strong specific adsorption of cells to clover roots. elimination of the plasmid pwz2 from bacteria caused loss of adsorption capability, and this property could be recoverd by introduction of the plasmid into bacterial cells. the results obtained indicate that the plasmid pwz2 contains gene(s) controlling the first stage of rhizobium-legume symbiosis which is a specific adsorption ... | 1980 | 7421604 |
| [ti plasmids of agrobacterium tumefaciens and their role in the formation of plant tumors]. | | 1980 | 7421799 |
| nodulation studies in species of genus cassia. | an examination of eight species of cassia for nodulation under natural unsterilized soils of different types from varied agroclimatic regions, as well as under aseptic conditions, inoculated with rhizobia, representing all the 8 cross inoculation groups, showed lack of nodulation in all the tested species. the absence of specific strains of rhizobia and the morpho-physiological features of the non-nodulating species of cassia were considered the possible non-nodulating causes. | 1980 | 7424218 |
| growth of rhizobia in protein hydrolysates. | sixteen nitrogen-rich agricultural and industrial wastes and by-products, such as vegetable waste, lasora (cordia myxa l.), meat waste, water-hyacinth (eichhornia crassipes), and pea (pisum sativum l.) husks were partially hydrolysed to amino acids with the help of acetic acid of 1, 5, 10, 15, and 20% concentration. in general, 10-20% acetic acid gave the highest amounts of amino acids. each protein hydrolysate, separately or/and in proper combination, was substituted with the nutrient yeast ext ... | 1980 | 7424226 |
| effect of fungicides on growth of rhizobium japonicum in vitro. | | 1980 | 7426785 |
| relationship of plasmids responsible for hairy root and crown gall tumorigenicity. | three strains of agrobacterium rhizogenes were examined for plasmids. strains 15834 and a4 contained essentially identical large plasmids, par15834c and para4c, respectively (approximately 260 x 10(6) daltons). these plasmids can dissociate to two smaller plasmid species. strain tr105 contained only a single plasmid, which was homologous with the dissociation product of par15834c, par15834b. plasmid par15834c shared little overall sequence homology with other ti plasmids. one region of conserved ... | 1980 | 7430069 |
| tumor formation and rhizogenicity of agrobacterium rhizogenes carrying ti plasmids. | octopine ti plasmids were introduced into different agrobacterium rhizogenes strains. transconjugants became able to utilize octopine and to induce aberrant tumors, the surface of which was all covered wioth roots of different size and morphology. the plasmids endogenous in a. rhizogenes were shown to be compatible with incrh-1 ti plasmids. | 1980 | 7439687 |
| agrobacterium radiobacter prosthetic valve endocarditis. | | 1980 | 7447191 |
| evidence that associated soil bacteria may influence root hair infection of actinorhizal plants by frankia. | nodulation of actinorhizal plants (alnus rubra bong, and others) by isolated frankia strains occurred either at a low frequency or not at all under axenic conditions. but nodulation was achieved under nonsterile conditions and four strains of bacteria were isolated which promoted nodulation when plants were inoculated with the bacteria plus frankia. four strains of pseudomonas cepacia also promoted nodulation. root hair deformation occurred when roots of a. rubra were inoculated with these bacte ... | 1980 | 7459718 |
| [spectral studies of the cytochrome p-450 of rhizobium lupini bacteroids]. | | 1981 | 7460755 |
| the electron transport chain of rhizobium trifolii. | the presence of a branched respiratory chain in rhizobium trifolii grown in batch culture on a defined medium was demonstrated. the branches of the respiratory chain differ in sensitivity to inhibition by cyanide and in affinity for oxygen. the branching point is localized at cytochrome b-555. electron flow from cytochrome b-555 via cytochrome c-549 and cytochrome a-597 towards oxygen has a relatively low affinity for oxygen and is sensitive to inhibition by cyanide. the second terminal oxidase ... | 1980 | 7460910 |
| elaboration of cellulose fibrils by agrobacterium tumefaciens during attachment to carrot cells. | the attachment of virulent strains of agrobacterium tumefaciens to plant cells is the first step in the bacterial induction of tumors. binding of a. tumefaciens to carrot tissue culture cells occurred as a two-step process. the initial step was the attachment of the bacteria to the plant cell wall. living plant cells were not required. bacterial attachment to heat-killed or glutaraldehyde-fixed carrot cells proceeded with only slightly altered kinetics and unaltered bacterial strain specificity. ... | 1981 | 7462151 |
| the fix escherichia coli region contains four genes related to carnitine metabolism. | anaerobic carnitine metabolism in escherichia coli was recently shown to involve six genes organized in the cai operon and located at the first minute on the chromosome. the dna sequence lying at the 5' end of the cai locus was further investigated. it contains four open reading frames organized as an operon. in vivo overexpression of this dna region revealed four polypeptides with apparent molecular masses of 27, 33, 45 and 6 kda. these proteins displayed significant amino acid sequence homolog ... | 1995 | 7473063 |
| high angle and ligand-induced low angle dna bends incited by occr lie in the same plane with occr bound to the interior angle. | the occr protein of agrobacterium tumefaciens activates transcription of the occq operon in response to octopine. octopine shortens the dnase i footprint of occr and relaxes an occr-incited dna bend. in this study, we used hydroxyl radical footprinting to show that occr contacts only one face of the operator. this contact spans 50 nucleotide pairs in the absence of octopine, and 39 nucleotide pairs in the presence of octopine. octopine enhanced protection of the central region of the footprint. ... | 1995 | 7473714 |
| the sixty nucleotide occr operator contains a subsite essential and sufficient for occr binding and a second subsite required for ligand-responsive dna bending. | occr is a transcriptional regulatory protein of agrobacterium tumefaciens that activates the occq operon in response to octopine, an arginine derivative released from plant tumors. occr binds to its operator with similar affinity and the same stoichiometry in the presence or absence of octopine, but octopine shortens the protein's dnase i footprint and partially relaxes an occr-incited dna bend. in this study, resections and other alterations of the operator were used to demonstrate that 19 nucl ... | 1995 | 7473744 |
| is hodgkin's disease a human counterpart of bacterially induced crown-gall tumours? | | 1995 | 7475853 |
| the bacterial 'enigma': cracking the code of cell-cell communication. | in recent years it has become clear that the production of n-acyl homoserine lactones (n-ahls) is widespread in gram-negative bacteria. these molecules act as diffusible chemical communication signals (bacterial pheromones) which regulate diverse physiological processes including bioluminescence, antibiotic production, plasmid conjugal transfer and synthesis of exoenzyme virulence factors in plant and animal pathogens. the paradigm for n-ahl production is in the bioluminescence (lux) phenotype o ... | 1995 | 7476157 |
| organization of host-inducible transcripts on the symbiotic plasmid of rhizobium sp. ngr234. | in a systematic approach to identify genes involved in the early steps of the legume-rhizobium symbiosis, we studied transcription patterns of symbiotic plasmid-borne loci. a competitive hybridization procedure was used to identify dna restriction fragments carrying genes whose expression is enhanced by plant root exudates or by purified flavonoids. fragments containing induced genes were then located on the physical map of the 500 kb pngr234a. new inducible loci as well as previously described ... | 1995 | 7476161 |
| mutational analysis of a conserved motif of agrobacterium tumefaciens vird2. | the vird2 polypeptide from agrobacterium tumefaciens, in the presence of vird1, introduces a site- and strand-specific nick at the t-dna borders. a similar reaction at the origin of transfer (orit) of plasmids is essential for plasmid transfer by bacterial conjugation. a comparison of protein sequences of vird2 and its functional homologs in bacterial conjugation and in rolling circle replication revealed that they share a conserved 14 residue segment, hxdxxx(p/u)huhuuux [residues 126-139 of vir ... | 1995 | 7479069 |
| stress activation of a bean hydroxyproline-rich glycoprotein promoter is superimposed on a pattern of tissue-specific developmental expression. | the hrgp4.1 gene, which encodes a cell wall hydroxyproline-rich glycoprotein, was isolated from a genomic library of bean (phaseolus vulgaris l.). two transcripts, one induced by wounding and one by elicitation, were transcribed from the same initiation site. the gene encodes a polypeptide of 580 amino acids with the amino terminal half consisting of repeats of the sequence serine-(proline)4-lysine-histidine-serine-(proline)4-(tyrosine)3-histidi ne and the carboxyl-terminal half composed of repe ... | 1995 | 7480331 |
| a rapeseed cold-inducible transcript encodes a phosphoenolpyruvate carboxykinase. | we have isolated a clone corresponding to a new cold-regulated gene from a cdna library made from rapeseed (brassica napus cv samourai) cold-acclimated etiolated seedlings. sequence analysis and homology searches showed that this clone encodes a protein highly homologous to the atp-dependent phosphoenolpyruvate carboxykinase (pepck; ec 4.1.1.49) from saccharomyces cerevisiae, trypanosoma, rhizobium sp., and escherichia coli; we refer to the b. napus clone as bnpepck. a potential atp-binding site ... | 1995 | 7480349 |
| universal pcr primers for detection of phytopathogenic agrobacterium strains. | two pcr primer pairs, based on the vird2 and ipt genes, detected a wide variety of pathogenic agrobacterium strains. the endonuclease domain of vird2 protein, which cleaves transferred dna (t-dna) border sequences, is highly conserved; primer oligonucleotides specific for the endonuclease portion of vird2 detected all pathogenic strains of agrobacterium tested. pcr primers corresponding to conserved sequences in ipt, the t-dna-borne cytokinin synthesis gene, detected only agrobacterium tumefacie ... | 1995 | 7487020 |
| characterization of rhizosphere colonization by luminescent enterobacter cloacae at the population and single-cell levels. | a bioluminescence marker system was used to characterized colonization of the rhizosphere by a bacterial inoculum, both in terms of population activity and at the single-cell level. plasmid pqf70/44, which contains luxab genes under the control of a strong constitutive phage promoter, was introduced into the rhizobacterium and model biocontrol agent enterobacter cloacae. light output from the lux-modified strain was detected by luminometry of samples from growing cultures of e. cloacae and from ... | 1995 | 7487027 |
| cloning, nucleotide sequencing, and expression of an opine dehydrogenase gene from arthrobacter sp. strain 1c. | the gene coding for opine dehydrogenase from arthrobacter sp. strain 1c was cloned onto plasmid pbluescript ks(-), and the nucleotide sequence of the 1,077-bp open reading frame consisting of 359 codons was identified as the odh gene. transformed escherichia coli cells overproduced nad+-dependent opine dehydrogenase under control of the promoter of the lac gene on pbluescript ks(-). | 1995 | 7487048 |
| adenosine-5'-triphosphate-sulfurylase from arabidopsis thaliana and escherichia coli are functionally equivalent but structurally and kinetically divergent: nucleotide sequence of two adenosine-5'-triphosphate-sulfurylase cdnas from arabidopsis thaliana and analysis of a recombinant enzyme. | atp-sulfurylase, the first enzyme of sulfate assimilation, catalyzes the formation of adenosine-5'-phosphosulfate from atp and sulfate. here we report that the higher plant, arabidopsis thaliana, contains a three-member, expressed gene family encoding plastid localized forms of atp sulfurylase. three cdnas from a. thaliana, designated aps1, aps2, and aps3, were isolated by their ability to functionally complement a met3 (atp sulfurylase) mutant strain of saccharomyces cerevisiae (yeast). the nuc ... | 1995 | 7487067 |
| properties of d-hydantoinase from agrobacterium tumefaciens and its use for the preparation of n-carbamyl d-amino acids. | agrobacterium tumefaciens strain 47c expresses an inducible d-hydantoinase that catalyzes the formation of optically pure n-carbamyl d-amino acids from racemic hydantoin precursors. the d-hydantoinase was shown to be active and stable at elevated temperatures and ph values, thus affording favorable bioreaction conditions that result in the racemization of dl-hydantoins to the utilizable d-isomer. the enzyme demonstrated optimal reaction kinetics at ph 10 and 70 degrees c, was not activated by me ... | 1995 | 7488185 |
| biosynthesis of azorhizobium caulinodans nod factors. study of the activity of the nodabcs proteins by expression of the genes in escherichia coli. | by in vitro and in vivo studies with escherichia coli expressing different combinations of the nodabcs genes of azorhizobium caulinodans, nod factor intermediates were identified and their structures determined using mass spectrometry. substrate-product relationships were studied by time course experiments, and the nod factor biosynthetic pathway was partially resolved. e. coli strains, harboring noda and/or nodb, did not produce nod metabolites, whereas the strain expressing nodc produced chito ... | 1995 | 7493950 |
| an agrobacterium virulence factor encoded by a ti plasmid gene or a chromosomal gene is required for t-dna transfer into plants. | mutagenesis of the vir region on the ti plasmid of agrobacterium tumefaciens revealed a new locus, virj, that is induced by the plant-wound signal molecule, acetosyringone (as). virj lies between vira and virb, and is transcribed in the same direction. the amino acid sequence of virj is similar to a region of a previously characterized chromosomal gene, acvb, required for virulence. virj can complement the avirulent phenotype of an acvb mutant, indicating that virj and acvb encode the same facto ... | 1995 | 7494475 |
| multiple homologues of luxr and luxi control expression of virulence determinants and secondary metabolites through quorum sensing in pseudomonas aeruginosa pao1. | in pseudomonas aeruginosa pao1, expression of elastase is dependent upon an interaction between the positive transcriptional activator lasr and the auto-inducer molecule n-(3-oxododecanoyl)-l-homoserine lactone (oddhl), the synthesis of which is directed by lasi. previously we have shown that in pan067, an elastase-negative mutant of pao1, elastase production can be restored to some extent by addition of exogenous n-(3-oxohexanoyl)-l-homoserine lactone (ohhl). here we report that pan067 is also ... | 1995 | 7494482 |
| identification of a chemotaxis operon with two chey genes in rhodobacter sphaeroides. | a large chemotaxis operon was identified in rhodobacter sphaeroides ws8-n using a probe based on the 3' terminal portion of the rhizobium meliloti chea gene. two genes homologous to the enteric chey were identified in an operon also containing chea, chew, and cher homologues. the deduced protein sequences of che gene products were aligned with those from escherichia coli and shown to be highly conserved. a mutant with an interrupted copy of chea showed normal patterns of swimming, unlike the equ ... | 1995 | 7494484 |
| nods is an s-adenosyl-l-methionine-dependent methyltransferase that methylates chitooligosaccharides deacetylated at the non-reducing end. | in response to phenolic compounds exuded by the host plant, symbiotic rhizobium bacteria produce signal molecules (nod factors), consisting of lipochitooligosaccharides with strain-specific substitutions. in azorhizobium caulinodans strain ors571 these modifications are an o-arabinosyl group, an o-carbamoyl group, and an n-methyl group. several lines of evidence indicate that the nods gene located in the nodabcsuij operon is implicated in the methylation of nod factors. previously we have shown ... | 1995 | 7494487 |
| derepression of the activity of genetically engineered heat shock factor causes constitutive synthesis of heat shock proteins and increased thermotolerance in transgenic arabidopsis. | athsf1 is a heat shock transcription factor (hsf) of arabidopsis that is constitutively expressed but its activity for dna binding, trimer formation and transcriptional activation of heat shock (hs) genes is repressed at normal temperatures. in this study the functional properties of chimeric hsf-glucuronidase (gus) fusion proteins were tested. ectopic expression of hsf-gus or gus-hsf in transgenic arabidopsis plants resulted in a derepression of hsf functions as shown by trimer formation, speci ... | 1995 | 7496404 |
| horizontal gene transfer: regulated expression of a tobacco homologue of the agrobacterium rhizogenes rolc gene. | a tobacco homologue (trolc) of the rolc gene of the agrobacterium rhizogenes ri-plasmid was cloned and sequenced from nicotiana tabacum l. cv. havana 425. the coding region of trolc is similar in sequence (69-87% for dna and 54-89% for the deduced amino acid sequence) to rolc genes of the agropine, mannopine, and mikimopine strains of ri-plasmids and the n. glauca rolc homologue. southern analyses showed that trolc is encoded by a small gene family derived from the tomentosiformis ancestor of to ... | 1995 | 7500950 |
| genetics of galactose metabolism of erwinia amylovora and its influence on polysaccharide synthesis and virulence of the fire blight pathogen. | galactose metabolism mutants of erwinia amylovora were created by transposon insertions and characterized for their growth properties and interaction with plant tissue. the nucleotide sequence of the gale gene was determined. the gene, which encodes udp-galactose 4-epimerase, shows homology to the gale genes of escherichia coli, neisseria gonorrhoeae, rhizobium meliloti, and other gram-negative bacteria. cloned dna with the gale and with the galt and galk genes did not share borders, as judged b ... | 1994 | 7507102 |
| lipopolysaccharide epitope expression of rhizobium bacteroids as revealed by in situ immunolabelling of pea root nodule sections. | to investigate the in situ expression of lipopolysaccharide (lps) epitopes on nodule bacteria of rhizobium leguminosarum, monoclonal antibodies recognizing lps macromolecules were used for immunocytochemical staining of pea nodule tissue. many lps epitopes were constitutively expressed, and the corresponding antibodies reacted in nodule sections with bacteria at all stages of tissue infection and cell invasion. some antibodies, however, recognized epitopes that were only expressed in particular ... | 1994 | 7511581 |