Publications

[effectiveness of symbiotic n2-fixation in leguminous plants, as affected by inoculation with rhizobia, by substrate, n-fertilizing, and 14c-sucrose application (author's transl)].	cultivation experiments (mitscherlich-vessels, quartz sand, 15n-labelled soil, 15n-fertilizer) showed, that various strains of rhizobium lupini (white and yellow lupines) and of rhizobium leguminosarum (field beans and peas) induced a different n2-fixation of the inoculated plants, the most effective rhizobium strains being 367a, cz, t3, 271 (rh. lupini), and azotogen (rh, leguminosarum). yellow lupines and field bean plants were supplied with n2 from the air considerably better than white lupin ...	1980	6252716
[harmfulness of bacterial gall of grape and the species makeup of its causative agent in moldavia].		1980	6445036
heterozygosis of phage 16-3 of rhizobium meliloti: moderate level of mismatch repair or gene conversion.	analysis of clear/turbid mottled (heterozygotic plaques) of rhizobium meliloti temperate phage 16-3 indicates that the efficiency of repair at three sites (ti3, ti4, and ti5) in the c cistron is 2 to 20-fold less than that observed in e. coli phage lambda. in agreement with this conclusion, heterozygotic plaques were observed at similar frequency in crosses where point and small deletion mutants were combined, suggesting that in rhizobium, dna molecules with short single-stranded loops can escap ...	1980	6450309
expression of ti-plasmid dna in e. coli: comparison of homologous fragments cloned from ti plasmids of agrobacterium strains c58 and ach5.	fragments of two ti plasmids from agrobacterium tumefaciens were cloned and studied for cross-hybridization. homologous fragments were further investigated for areas of strong homology and mapped with various restriction enzymes. the fragments were inserted in two directions and the recombinant plasmid was brought into e. coli strains producing minicells. about five proteins were found to be coded by those fragments of the ti plasmids.	1980	6765583
chemoautotrophic growth of hydrogen-uptake-positive strains of rhizobium japonicum.	recently reported research from this laboratory has demonstrated the autotrophic growth of certain hydrogen-uptake-positive strains of rhizobium japonicum and defined minimal conditions for such growth. ribulose 1,5-bisphosphate carboxylase has been detected in autotrophically growing cells, but at low specific activity. moreover, growth rates were low, and growth ceased at low cell densities. we report here improved autotrophic growth rates of r. japonicum sr through the use of a modified miner ...	1980	6767687
polyol metabolism by rhizobium trifolii.	in rhizobium trifolii 7000, the polyols myo-inositol, xylitol, ribitol, d-arabitol, d-mannitol, d-sorbital, and dulcitol are metabolized by inducible nicotinamide adenine dinucleotide-dependent polyol dehydrogenases. five different polyol dehydrogenases were recognized: inositol dehydrogenase, specific for inositil; ribitol dehydrogenase, specific for ribitol; d-arabitol dehydrogenase, which oxidized d-arabitol, d-mannitol, and d-sorbitol; xylitol dehydrogenase, which oxidized xylitol and d-sorb ...	1980	6767702
[preparation and properties of new catabolic substrates for two types of oncogenic plasmids of agrobacterium tumefaciens].	reduction of the schiff bases formed between glucose, mannose or galactose with glutamic acid yields products related both structurally and biologically to agropine and to a derivative of agropine present in crown gall tumours. the catabolism of these compounds is coded for by octopine and agropine ti-plasmids of agrobacterium tumefaciens.	1980	6772324
comparative studies on the regulation of tryptophan synthesis.	in vitro dna recombination techniques have revolutionized the study of genetic control of biosynthetic pathways. using examples drawn from the pathway of tryptophan synthesis, approaches to the deciphering of regulatory signals and response mechanisms through transposition of dna segments and dna sequence analysis will be presented. after reviewing the known chromosomal arrangements and regulatory patterns of trp genes in the bacterial groups studied so far, and describing the results of transfe ...	1980	6772375
lipid-bound sugars in rhizobium meliloti.		1980	6447479
polarographic measurement of h2 in aqueous solutions.		1980	6776845
rhizosphere microflora and colonization of wheat roots by gaeumannomyces graminis var. tritici after foliar application of urea and benomyl.	the effect of foliar application of 2% urea and 0.6% benomyl on changes in colonization of the rhizosphere by microorganisms and of roots by the fungus gaeumannomyces graminis (sacc.) arx et olivier var. tritici walker was followed in vegetation glass-house experiments. treatment with a urea solution resulted in increased counts of bacteria (82%), pseudomonas fluorescens (46%), agrobacterium sp. (31%) and antagonistic bacteria with respect to the used fungus isolate and in a decreased occurrence ...	1980	6777280
homologous serological analysis of rhizobium meliloti strains by immunodiffusion.	the homologous titers of antisera prepared against 24 rhizobium meliloti strains ranged from 8 to 64 in immunodiffusion tests when intact cells were used as test antigens. the antisera titers against a number of strains were higher when heated or ultrasonicated cell preparations were used as sources of antigens. the minimum concentration of intact cells required to produce a positive reaction varied between strains and the heat treatment of the cells of some strains increased the detectability o ...	1980	6780176
interspecies homology of nitrogenase genes.	cloned nitrogen fixation (nif) genes from klebsiella pneumoniae hybridize to dna from 19 out of 19 widely divergent nitrogen-fixing bacterial strains but do not hybridize to dna from 10 different non-nitrogen-fixing species. k. pneumoniae nif dna fragments that hybridize to dna from other species contain part of the three structural genes that code for nitrogenase polypeptides. we have utilized this homology to clone an ecori restriction endonuclease fragment from rhizobium meliloti that hybridi ...	1980	6987649
indirect methods of determination of activity of root-nodule bacteria.	significant correlations exist between the ability of root-nodule bacteria to fix molecular nitrogen and some of their properties (accumulation of riboflavin, cobalamine, atp, cell pyrolysis, effect on plant vegetation characteristics) which can be used for quickly assessing the activity of the process in individual strains of rhizobia.	1980	6991379
biochemical genetics of nitrogen fixation.		1980	6999325
chemical structure and inhalation toxicity of lipopolysaccharides from bacteria on cotton.	lipopolysaccharides from different bacteria isolated from cotton were purified and chemically analyzed. their pulmonary toxicity to animals was tested in inhalation tests. lipopolysaccharides from agrobacterium and xanthomonas were shown to differ from the others in that they contained no heptose and no non-hydroxylated fatty acids with a chain length of 12, 14, or 16 carbon atoms. lipopolysaccharides from pseudomonas putida, enterobacter agglomerans, and klebsiella oxytoca were found to cause a ...	1980	7000706
expression of large plasmids in the endosymbiotic form of rhizobium leguminosarum.	isolated plasmid dna from rhizobium leguminosarum was hybridised with cellular rna from broth-cultured bacteria and endosymbiotic bacteroids. from these hybridisation, experiments it is concluded that plasmid genes are strongly expressed in bacteroids and only weakly or not at all in bacteria. from the hybridisation of plasmid dna with the cloned structural nif genes of klebsiella pneumoniae it is shown that at least part of the nif genes are located on a plasmid.	1980	7001365
3-o-methyl-l-rhamnose from a rhizobium capsular polysaccharide.		1980	6893167
broad host range dna cloning system for gram-negative bacteria: construction of a gene bank of rhizobium meliloti.	a broad host range cloning vehicle that can be mobilized at high frequency into gram-negative bacteria has been constructed from the naturally occurring antibiotic resistance plasmid rk2. the vehicle is 20 kilobase pairs in size, encodes tetracycline resistance, and contains two single restriction enzyme sites suitable for cloning. mobilization is effected by a helper plasmid consisting of the rk2 transfer genes linked to a cole1 replicon. by use of this plasmid vehicle, a gene bank of the dna f ...	1980	7012838
isolation of cofactor common to molybdenum-containing enzymes: nitrate reductase from lupine bacteroids and xanthine oxidase from milk.	a quantitative method for the anaerobic isolation of a molybdenum cofactor from two molybdenum-containing enzymes, nitrate reductase from the bacteroids of lupine nodules and xanthine oxidase from milk, is described. it was established that the cofactor consists of an aromatic component and a number of amino acid residues bound to it. the structural and catalytic function of the molybdenum cofactor in the enzyme was established.	1980	6895606
short-term effect of ammonium chloride on nitrogen fixation by azotobacter vinelandii and by bacteroids of rhizobium leguminosarum.		1980	6928406
foreign dna sequences in crown gall teratomas and their fate during the loss of the tumorous traits.		1980	6929944
the effect of waterlogging on the synthesis of the nitrogenase components in bacteroids of rhizobium leguminosarum in root nodules of pisum sativum.		1980	6930267
generalized transduction in rhizobium meliloti.	the phage 11 of r. meliloti performs generalized transduction. this was confirmed by the variety of single markers transferred and by separating transducing particles containing budr-labelled bacterial dna. the transduction frequencies depended on the marker. linked alleles were mapped by cotransduction on fragments of bacterial dna equal in size to the phage dna. with crosses between antibiotic resistancy and auxotrophic markers a partial map was constructed with str, cml, pur-19, and leu-44 si ...	1980	6930536
screening for mutants of rhizobium japonicum with defects in nitrogen fixing ability.	mutants of rhizobium japonicum with reduced ex planta nitrogenase activity could be isolated with high frequency by direct screening of ultra-violet mutagenized bacteria growing as spots on the surface of an appropriate agar medium permitting derepression of nitrogenase synthesis. small glass chambers fitted with a serum cap were pushed into the agar around each spot of growth, forming a small enclosed gas space which was made to 10% acetylene, permitting assessment of nitrogenase activity by th ...	1980	6934662
plasmid dna of agrobacterium tumefaciens detected in a presumed habituated tobacco cell line.	'tabac anergié' tissue has been used by many investigators as a habituated tobacco cell line. in this study, we have found sequences which are homologous to approximately 9 megadaltons of an agrobacterium octopine-type plasmid in dna isolated from 'tabac anergié' tissue. these t-dna sequences were shown to be the same 'core dna' sequences found to be present in several other unorganized tumor lines which have been studied in our laboratory. the t-dna was also shown to be integrated into plant dn ...	1980	6935494
turnover of nitrogenase and leghemoglobin in root nodules of pisum sativum.	turnover rates of the two nitrogenase components and leghemoglobin in root nodules of pea plants nodulated with rhizobium leguminosarum were determined with three different methods: 1, kinetics of 35s incorporation into protein; 2, pulse-chase experiments; 3, chloramphenicol inhibition of bacteroid protein synthesis. methods 1 and 3 revealed that the turnover rates of the two nitrogenase components and leghemoglobin are identical to the average rate of bacteroid and plant nodule protein turnover ...	1980	6938244
a strain marker in rhizobium trifolii based on the absorption of congo-red.	it is widely recognized that most rhizobia absorb congo-red weakly when grown on agar media containing this dye. in contrast to this generalized behaviour, an ineffective strain of rhizobium trifolii (coryn) has been found which strongly absorbs the dye, producing growth of a very deep-red colour on yeast-extract mannitol agar, supplemented with congo-red (0.025 g/l). assays for dye absorption characteristics on this medium with 21 strains of r. trifolii showed that coryn could be readily differ ...	1980	6999774
a simple device of an improvised fermentor for production of rhizobial culture.	a simple new batch fermentor, suitable for both laboratory and industrial small scale cultivation of micro-organisms, particularly rhizobia, was designed and constructed. it was found to operate as a conventional stirring tank reactor. the device reliably ensures the sterility of cultivation, irrespective of its duration. its installation costs are relatively low, it does not show a high consumption of energy for stirring, the operation is very simple and does not require maintenance of complica ...	1980	6999775
[testing the virulence of nodule bacteria cultivated on the embryos of leguminous plants].		1980	7003326
isolation and characterization of an r-prime plasmid from rhizobium meliloti.	using a simple enrichment procedure, we isolated an r-prime derivative of plasmid r68.45 carrying a 17.8-megadalton segment of the rhizobium meliloti 41 chromosome. the chromosomal segment carried on this plasmid (pgy1) includes the markers cys-24+, cys-46+, and att16-3. plasmid pgy1 mobilized the chromosome in a polarized way starting from the region of homology, but cannot promote chromosome transfer from other sites. the att16-3 site on pgy1 allowed the integration of phage 16-3 into pgy1, an ...	1980	6986354
autotransmissible resident plasmid of rhizobium meliloti.	a resident plasmid of wild-type strains of rhizobium meliloti of 59.6 megadaltons has been shown to be transferred at a high frequency to "cured" strains of this bacterial species. this plasmid, named pez1, that confers phage-sensitivity to cells carrying it is also transmissible to escherichia coli and from it to "cured" r. meliloti strains.	1980	6988674
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
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
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
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
nitrogen fixation by nitrate reductase deficient mutants of rhizobium japonicum.		1980	7194311
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
[inoculation of rhizobium phaseoli onto different species of the genus phaseolus originating in mexico].		1980	7291776
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
[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
[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
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
isolation & characterization of antibiotic resistant mutants of cowpea rhizobium 32hi.		1980	7228122
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
[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
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
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
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
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
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
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
[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
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
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
association of azospirillum with grass roots.	the association between grass roots and azospirillum brasilense sp 7 was investigated by the fahraeus slide technique, using nitrogen-free medium. young inoculated roots of pearl millet and guinea grass produced more mucilaginous sheath (mucigel), root hairs, and lateral roots than did uninoculated sterile controls. the bacteria were found within the mucigel that accumulated on the root cap and along the root axes. adherent bacteria were associated with granular material on root hairs and fibril ...	1980	16345490
promotion of infection thread formation by substances from rhizobium.	an extrinsic substance (es-6000) was isolated from the periplasmic space of rhizobium trifolii (strain 4s) cells by osmotic shock, using a high-density sucrose solution. this substance promoted infection thread formation in root hairs of white clover when inoculated together with the infectious strain (4s). however, es-6000 obtained from another rhizobial species and from strain a1, which is a noninfectious mutant strain obtained from strain 4s, did not have this effect. the promoter in the es-6 ...	1980	16345501
use of two-dimensional polyacrylamide gel electrophoresis to identify and classify rhizobium strains.	fifty-seven strains of various rhizobium species were analyzed by two-dimensional gel electrophoresis. since the protein pattern on such gels is a reflection of the genetic background of the tested strains, similarities in pattern allowed us to estimate the relatedness between these strains. all group ii rhizobia (slow growing) were closely related and were very distinct from group i rhizobia (fast growing). rhizobium meliloti strains formed a distinct group. the collection of r. leguminosarum a ...	1980	16345514
interaction between a non-nodulating and an ineffective mutant of rhizobium trifolli resulting in effective (nitrogen-fixing) nodulation.	a noninvasive (non-nodulating) mutant of rhizobium trifolii when mixed with an ineffective (non-nitrogen-fixing) mutant gives rise to effective (nitrogen-fixing) nodules.	1980	16345518
use of two-dimensional polyacrylamide electrophoresis to demonstrate that putative rhizobium cross-inoculation mutants actually are contaminants.	two-dimensional polyacrylamide electrophoresis was used to determine that mutants of rhizobium trifolii dt6, claimed to be capable of effectively nodulating soybeans, were actually rhizobium japonicum 110 contaminants isolated from the parent dt6 culture.	1980	16345520
density centrifugation method for recovering rhizobium spp. from soil for fluorescent-antibody studies.	a density centrifugation procedure has been developed as a replacement for soil flocculation and clarification steps employed in quantitative fluorescent-antibody studies on rhizobium in soils. near-quantitative recovery of added cells of two strains of rhizobium japonicum and two strains of r. phaseoli was achieved from six soils with various properties. it is proposed that this technique may prove useful in separating other soil microorganisms from soil particles in ecological studies employin ...	1980	16345522
method for testing degree of infectivity of rhizobium meliloti strains.	the infectiveness of different strains of rhizobium meliloti was tested with a technique that uses the addition of tetracycline to the root medium. to stop the infection, the antibiotic was added some time after the inoculation of medicago sativa plants. a coefficient of infectivity for each strain was calculated according to the number of nodules that appeared with and without the addition of the antibiotic. this method seems useful in infectivity studies and is simpler and easier to perform th ...	1980	16345574
accumulation of soybean lectin-binding polysaccharide during growth of rhizobium japonicum as determined by hemagglutination inhibition assay.	a hemagglutination inhibition assay was used to estimate the presence of soybean lectin-binding polysaccharide in whole culture, culture supernatant, and isolated exopolysaccharide of rhizobium japonicum usda 138. the occurrence of 0.1 to 0.2 mug of lectin-binding polysaccharide could be detected within 2 h with a 0.5-ml total sample. lectin-binding polysaccharide was detected in all preparations during both exponential and stationary growth phases. the formation of lectin-binding polysaccharide ...	1980	16345578
r-plasmid transfer in zymomonas mobilis.	conjugal transfer of three incp1 plasmids and one incfii plasmid into strains of the ethanol-producing bacterium zymomonas mobilis was obtained. these plasmids were transferred at high frequencies from escherichia coli and pseudomonas aeruginosa into z. mobilis and also between different z. mobilis strains, using the membrane filter mating technique. most of the plasmids were stably maintained in z. mobilis, although there was some evidence of delayed marker expression. a low level of chromosoma ...	1980	16345598
evidence suggesting protozoan predation on rhizobium associated with germinating seeds and in the rhizosphere of beans (phaseolus vulgaris l.).	changes in populations of microorganisms around germinating bean (phaseolus vulgaris l.) seeds, in the rhizosphere of bean, and in a model rhizosphere were studied. strains of rhizobium phaseoli that were resistant to streptomycin and thiram were used, and as few as 300 r. phaseoli cells per g of soil could be enumerated with a selective medium that was devised. a direct role was not evident for bacterial competitors, lytic bacteria, antibiotic-producing microorganisms, bacteriophages, and bdell ...	1980	16345628
diversity and dynamics of indigenous rhizobium japonicum populations.	a simple method, based upon the separation of cellular proteins by sodium dodecyl sulfate (sds)-polyacrylamide gel electrophoresis, has been devised for distinguishing between isolates of rhizobium japonicum. eleven laboratory strains, previously classified into five serogroups, were analyzed by gel electrophoresis. groups determined subjectively according to protein patterns matched the serogroups, with one exception. most strains within serogroups could be distinguished from one another. for s ...	1980	16345658
scanning electron microscopy of rhizobium trifolii infection sites on root hairs of white clover.	white clover root hairs which were inoculated with rhizobium trifolii 4s (infectious strain) contained infection threads which were observed by light microscopy and scanning electron microscopy. three morphological types of root hairs retaining infection threads were recognized. the bacteria were strongly attached between the surfaces of two plant cell walls as follows: between surfaces of a root hair tip curled back on itself, between a protuberance from a root hair and its cell surface, or bet ...	1980	16345672
interrelations between meloidogyne javanica, rotylenchulus reniformis, and rhizobium sp. on vigna sinensis.	the interactions of meloidogyne javanica, rotylenchulus reniformis, and rhizobium sp. on cowpea seedlings were investigated. upon simultaneous inoculation with the two nematode species, m. javanica invaded first but did not affect root invasion by r. reniformis. m. javanica populations increased less in competition with r. reniformis than when present alone. preinvasion by r. renilormis significantly suppressed the number of m. javanica in the roots. inoculation of m. javanica and/or r. reniform ...	1980	19300672
starch contents in alfalfa nodules with effective and ineffective symbiotic responses.	rhizobium meliloti auxotrophic and ineffective mutants induced nodules containing: 9.35 microg of starch per mg of the plant tissue (wet wt.) in the case of strain his-240 which did not occupy host cells and 2.7 to 3.5 microg of starch in strains: arg-55, cys-243, cys-244 and cys-246 which occupied part of the host cells (bacteroidal zone). nodules induced by prototrophic and effective strains i.e. l5-30 (wilde type) and prototrophic transductants of arg-55 and his-240 mutants contained 0.13 to ...	1980	19852116
a comparison of two-point, three-point and deletion mapping in the c cistron of rhizobiophage 16-3, with an explanation for the recombination pattern.	a general tendency for additivity prevailed in recombination frequencies for two-point fine-structure mapping of 14 mutants in the c cistron of rhizobium meliloti phage 16-3, with little evidence of any marker effect. intracistronic three-point mapping indicated that double crossovers are rare. deletion mapping indicated that the two- and three-point mapping data gave the correct order of the mutations. a high frequency (5 to 8%) of c/c(+) heterozygotic phage progenies was observed in standard c ...	1980	17248999
methods for analysis of the c cistron of temperate phage 16-3 of rhizobium meliloti.	a series of clear mutants of the temperate phage 16-3 of rhizobium meliloti were isolated that included various point and deletion mutants of the c cistron, coding for the phage repressor. it was observed that recombinant genotypes, such as c(+) and ti (temperature-sensitive allele), which form turbid plaques, can be detected quantitatively as lysogenic colonies and scored even at frequencies as low as 10(-6). point mutations, deletions and the autonomy of intracistronic second-site mutations we ...	1980	17249000
regulation of rhizobium nitrogen fixation by the unadenylylated glutamine synthetase i system.	rhizobium sp. 32h1 glutamine auxotrophs have a complex phenotype: a highly adenylylated glutamine synthetase [gs; l-glutamate:ammonia ligase (adp-forming), ec 6.3.1.2] i and an undetectable gs ii (gs ii(-)). they are defective in the adenylylation cascade system for gs i. prototrophic revertants are of two classes: those (3204 type) which retain the adenylylated gs i phenotype but become gs ii(+), and those (3205 type) which acquire a constitutive unadenylylated gs i but remain gs ii(-). like th ...	1980	16592892
evaluation of the relative ureide content of xylem sap as an indicator of n(2) fixation in soybeans: greenhouse studies.	the use of the relative ureide content of xylem sap [(ureide-n/total n) x 100] as an indicator of n(2) fixation in soybeans (merr.) was examined under greenhouse conditions. acetylene treatments to inhibit n(2) fixation were imposed upon the root systems of plants totally dependent upon n(2) fixation as their source of n and of plants dependent upon both n(2) fixation and uptake of exogenous nitrate. significant decreases in the total n concentration of xylem sap from plants of the former type w ...	1980	16661509
early events in the infection of soybean (glycine max l. merr) by rhizobium japonicum: i. localization of infectible root cells.	the infectible cells of soybean roots appear to be located at any given time just above the zone of root elongation and just below the position of the smallest emergent root hairs. the location of infectible cells on the primary root at the time of inoculation was inferred from the position of subsequent nodule development, correcting for displacement of epidermal cells due to root elongation. marks were made on the seedling growth pouches at the time of inoculation to indicate the position of t ...	1980	16661570
nitrate effect on nitrogen fixation (acetylene reduction): activities of legume root nodules induced by rhizobia with varied nitrate reductase activities.	the effect of nitrate on symbiotic nitrogen fixation by root nodules of cowpea (vigna unguiculata l., walp., cv. california blackeye) and lupine (lupinus augustifolius l., cv. frost) plants inoculated with nitrate reductase-expressing and nitrate reductase-nonexpressing rhizobium strains were examined. nitrate reductase of rhizobium bacteroids in the nodules of cowpea and lupine reduced nitrate to nitrite. both cowpea and lupine nodules accumulated nitrite when grown in the presence of 15 millim ...	1980	16661223
oxyleghemoglobin-mediated hydrogen oxidation by rhizobium japonicum usda 122 des bacteroids.	oxyleghemoglobin was used to supply low concentrations of o(2) to h(2)-oxidizing bacteroids from rhizobium japonicum usda 122 des. the h(2) oxidation system of these bacteroids was capable of effectively utilizing o(2) at the low concentrations of o(2) expected to be found in soybean nodules. apparent k(m) values of approximately 10 nanomolar o(2) have been calculated for the oxyhydrogen reaction. these values include the k(m) values for both h(2) oxidation and endogenous substrate oxidation. ev ...	1980	16661247
interactions between rhizobia and lectins of lentil, pea, broad bean, and jackbean.	a quantitative method was developed to measure the binding of fluorescent-labeled lentil (lens esculenta moench), pea (pisum sativum l.), broad bean (vicia faba l.), and jackbean (canavalia ensiformis l., dc.) lectins to various rhizobium strains. lentil lectin bound to three of the five rhizobium leguminosarum strains tested. the number of lentil lectin molecules bound per r. leguminosarum 128c53 cell was 2.1 x 10(4). lentil lectin also bound to r. japonicum 61a133. pea and broad bean lectins b ...	1980	16661328
composition of the capsular and extracellular polysaccharides of rhizobium japonicum: changes with culture age and correlations with binding of soybean seed lectin to the bacteria .	the chemical compositions of the capsular and extracellular polysaccharides of two strains of rhizobium japonicum (311b 138 and 110) have been determined and correlated as a function of culture age with the ability of the bacteria from which they were obtained to bind soybean seed lectin.each of the polysaccharides contains approximately constant amounts of mannosyl, glucosyl, and galacturonosyl residues in a molar ratio of 1:2:1. in addition they contain variable amounts of galactosyl and 4-o-m ...	1980	16661379
host recognition in the rhizobium-soybean symbiosis.	polar binding of rhizobium japonicum to roots and root hairs of glycine soja (l.) sieb. and zucc. is specifically inhibited by d-galactose and n-acetyl-d-galactosamine, haptens of glycine max seed lectin. a protein, immunologically cross-reactive with the g. max seed lectin, is present in g. soja seed extracts. peptide mapping of the purified g. max and g. soja lectins indicates that the two are similar in structure. soybean lectin can be localized on the surface of both g. max and g. soja roots ...	1980	16661488
effect of irradiance on development of apparent nitrogen fixation and photosynthesis in soybean.	soybeans grown with 2 millimolar no(3) (-), which optimized apparent n(2) fixation by rhizobium symbionts, showed significantly different rates of apparent photosynthesis and c(2)h(2) reduction during seedling development at two irradiances. those physiological processes were lower for several weeks in plants grown at 1,500 microeinsteins per meter(2) per second than in those exposed to 700 microeinsteins per meter(2) per second. the irradiance-induced retardation was evident in short-term rates ...	1980	16661562
investigation of the h(2) oxidation system in rhizobium japonicum 122 des nodule bacteroids.	the h(2)-oxidizing complex in rhizobium japonicum 122 des bacteroids failed to catalyze, at a measurable rate, (2)h(1)h exchange from a mixture of (2)h(2) and (1)h(2) in presence of (2)h(2)o and (1)h(2)o, providing no evidence for reversibility of the hydrogenase reaction in vivo. in the h(2) oxidation reaction, there was no significant discrimination between (2)h(2) and (1)h(2), indicating that the initial h(2)-activation step in the over-all h(2) oxidation reaction is not rate-limiting. by use ...	1980	16661577