| thymidine incorporation into rhizobium meliloti. | thymidine is rapidly catabolized to thymine, beta-aminoisobutyric acid, and carbon dioxide by rhizobium meliloti cells. the incorporation of labelled thymidine into the dna of r. meliloti cells can be enhanced by the addition of low concentrations (10-20 micrograms/ml) of deoxyadenosine or other nucleosides (adenosine, uridine, guanosine). however, at high concentrations ( greater than 50 micrograms/ml) these compounds inhibit thymidine incorporation. conditions to obtain highly radioactive dna ... | 1979 | 157797 |
| changes in the nih guidelines for recombinant dna research (appendix 2: june-august, 1979). | | 1979 | 161243 |
| differential toxicities of mercury to bacteria and bacteriophages in sea and in lake water. | mixtures of anionic hgcl3-/hgcl4(2)-complexes were less toxic to terrestrial bacteria (erwinia herbicola, agrobacterium tumefaciens), to marine bacteria (acinetobacter sp., aeromonas sp.), and to bacteriophages (phi 11 m 15 of staphylococcus aureus and p1 of escherichia coli) than were equivalent concentrations of hg as cationic hg2+. the toxicity of 1 ppm hg to a. tumefaciens. aeromonas sp., and phi 11 m 15 was less in seawater than in lake water. inasmuch as the hg-cl species are formed in env ... | 1979 | 161510 |
| conversion of spheroplast symbiotes in a leafhopper, helochara communis fitch (cicadellidae: homoptera). | in mycetomes of leafhoppers, helochara communis, ultrastructural and histochemical studies revealed that spheroplast symbiotes (t-symbiotes) were converted to 'a-symbiotes' (so-called), with apparent loss of dna--a phenomenon reminiscent of rhizobium-bacteroid conversion in certain legume nodules. additional t-symbiotes were incorporated into the substance of these 'a-symbiotes'. | 1975 | 163130 |
| the nitrogen-fixing complex of bacteria. | | 1975 | 164247 |
| transfer of the tumor inducing factor in agrobacterium tumefaciens. | | 1975 | 164858 |
| hexopyranoside: cytochrome c oxidoreductase from agrobacterium. | | 1975 | 165382 |
| effect of adenine nucleotides on nad-dependent isocitrate dehydrogenases in rhizobia and bacteroids of legume root nodules. | atp, adp, amp and cyclic amp inhibit nad-dependent isocitrate dehydrogenase (l-s-isocitrate : nad-+ oxidoreductase, ec 1.1.1.41) from rhizobia but have no effect on the enzyme from corresponding bacteroids. this was observed using three rhizobial strains two of which are effective, and one ineffective, with lotus pedunculatus. using partially purified enzyme from each of the three rhizobial strains it was found that the adenine nucleotides inhibit the enzyme by competing with nad-+, not with iso ... | 1975 | 166683 |
| cyclic-amp phosphodiesterase activity in crown-gall tumor formation. | | 1975 | 169845 |
| purification and properties of cytochrome c-556 from agrobacterium tumefaciens b2a. | cytochrome c-556 from agrobacterium mefaciens b2a was isolated in a pure, homoneous state. the best purification procedure volved ammonium sulphate fractionation, delting on sephadex g-25, column chromatographic fractionation on deae- and cm-cellulose, and gel filtration on sephadex g-75 superfine. substitution of the cm-cellulose step by isoelectric focusing was successful. the purity of the final preparation is warranted by the purity index value, the electrophoretic patterns in the absence an ... | 1975 | 170180 |
| a comparison of dna from free living and endosymbiotic rhizobium leguminosarum (strain pre). | 1. bacteroids of rhizobium leguminosarum (strain pre) purified from root nodules of pisum sativum (var. 'rondo') by the standard procedure of differential centrifugation contained considerable contamination of mitochondrial material. this could be removed by incubation of the bacteroid preparation with 1 m kcl/1% deoxycholate. 2. the dna content of bacteroid cells of r. leguminosarum was found to have increased about three fold in comparison with the dna content of free living r. leguminosarum b ... | 1975 | 172157 |
| lipopolysaccharide as receptor for rhizobium phage 1p. | | 1975 | 172600 |
| a ferrodoxin from agrobacterium tumefaciens. | | 1975 | 179857 |
| [inhibitory analysis of the respiration of bacteroids from the nodules of yellow lupine]. | oxygen uptake and reduction of c2h2 by bacteroids was found to be inhibited by low concentrations of cyanide and azide. however, oxygen uptake was not completely suppressed even by 10(-3) m kcn. cyanide-resistant respiration was not inhibited by salicyl-hydroxamic acid, and seemed to be accomplished at the account of autoxidable flavo-proteins. a small light-reversible inhibition of respiration by carbon monoxide was found only in the bacteroids with a high rate of nitrogen fixation. rotenone, a ... | 1976 | 180385 |
| [ethylmethane sulfonate induction of auxotrophic mutants of rhizobium meliloti and their characteristics]. | ethylmethanesulfonate was used as a mutagen to induce auxotrophic mutants in rhizobium meliloti l5-30. survival of the culture depended on the period of time during which it was treated with the mutagen. thirteen auxotrophic mutants were isolated as a result of screening 1404 clones, and their requirements in growtn factors were determined. ethylmethanesulfonate induced mainly those mutants which required sulfur-containing amino acids. the activity of nitrogen fixation of the auxotrophic mutants ... | 1978 | 212672 |
| dna modifying enzymes of agrobacterium tumefaciens: effect of dna topoisomerase, restriction endonuclease, and unique dna endonuclease on plasmid and plant dna. | extracts from agrobacterium tumefaciens strain id135 contain three enzymes that have been characterized and partially purified. the first enzyme, a dna topoisomerase, appeared to relax only negatively twisted dna. the second enzyme, atu i, a type ii restriction endonuclease, generated the identical dna digestion pattern as ecorii when several dnas were used. the third enzyme, endonuclease a, showed a preference for superhelical dnas as substrates. when plasmid pck135dna, obtained from the virule ... | 1978 | 212732 |
| catabolite-repression-like phenomenon in rhizobium meliloti. | we report a phenomenon similar to catabolite repression in rhizobium meliloti. succinate, which allows the highest observed rate of growth of r. meliloti, caused an immediate reduction of beta-galactosidase activity when added to cells growing in lactose. a lac- mutant was unaltered in nodulation and nitrogen fixation capacities, but a pleiotropic mutant deficient in several catabolic properties was unable to produce effective nitrogen-fixing nodules. | 1978 | 214420 |
| polymyxin resistance in agrobacterium tumefaciens and its effect on crown gall tumor induction. | polymyxin-resistant (pblr) mutants of agrobacterium tumefaciens a6, b6, and b6m were isolated from polymyxin-sensitive (pbls) parent strains in a defined medium containing 600 microgram of polymyxin b sulfate per millilitre. the weight and number of tumors induced by pblr mutants on a variety of host plants such as carrot, potato, and pinto bean were 45--75% less than those induced by pbls wild types. the crude cell envelopes (cce) prepared from both pbls and pblr bacteria were inhibitory for tu ... | 1979 | 219950 |
| a c-terminal haem-bound cytochrome c-556 from agrobacterium tumefaciens, strain b-2a. amino acid composition and n-terminal sequence analysis. | | 1979 | 221262 |
| regulation of hydrogen utilisation in rhizobium japonicum by cyclic amp. | utilisation (uptake) of hydrogen gas by whole cells of rhizobium japonicum was found to be influenced by the carbon source(s) present in the growth medium, with activity being highest in a medium containing sugars. tricarboxylic acid cycle intermediates, such as malate, significantly reduced h2 utilisation. no reduction in the hydrogenase activity is observed when the enzyme is assayed directly by the tritium exchange method, indicating that the decrease in hydrogen uptake activity is not due to ... | 1979 | 222344 |
| on the efficiency of oxidative phosphorylation in membrane vesicles of azotobacter vinelandii and of rhizobium leguminosarum bacteroids. | | 1979 | 223842 |
| genetic engineering of symbiotic nitrogen fixation. | | 1979 | 227398 |
| [metlegoglobin reductase from lupine nodules. purification and properties]. | the purification procedure and properties of metlegoglobin reductase from the soluble fraction of lupine (lupinus luteus l.) nodules and from the proteins secreted by bacteroids rhizobium lupini in vitro are described. the properties of both forms of enzyme were found to be similar. a metlegoglobin reductase preparation purified 125-fold with a yield of 21% was obtained. the enzyme is strictly specific to the cofactor (nadh). no substrate specificity was revealed. the enzyme reduces oxidized cyt ... | 1979 | 227483 |
| iron-sulfur clusters in the molybdenum-iron protein component of nitrogenase. electron paramagnetic resonance of the carbon monoxide inhibited state. | carbon monoxide inhibits reduction of dinitrogen (n2) by purified nitrogenase from azotobacter vinelandii and clostridium pasteurianum in a noncompetitive manner (kii and kis = 1.4 x 10(-4) and 4.5 x 10(-4) and 7 x 10(-4) atm and 14 x 10(-4) atm for the two enzymes, respectively). the onset of inhibition is within the turnover time of the enzyme, and co does not affect the electron flux to the h2-evolving site. the kinetics of co inhibition of n2 reduction are simple, but co inhibition of acetyl ... | 1979 | 228701 |
| involvement of a plasmid in the hairy root disease of plants caused by agrobacterium rhizogenes. | | 1979 | 231271 |
| rapid mapping of transposon insertion and deletion mutations in the large ti-plasmids of agrobacterium tumefaciens. | a procedure is presented, that has allowed the rapid assignment of transposon tn1 and tn7 insertion sites in the large (130 md) nopaline ti-plasmid ptic58, to specific restriction enzyme fragments. total bacterial dna is isolated from agrobacterium tumefaciens strain c58 mutants that carry a transposon in their ti-plasmid, and digested with an appropriate restriction endonuclease. the fragments are separated on an agarose gel, denatured and transferred to nitrocellulose filters. these are hybrid ... | 1979 | 231764 |
| agrobacterium ti plasmids as a tool for genetic engineering in plants. | | 1979 | 233066 |
| small-scale techniques for the analysis of recombinant plasmids. | using the cloning of part of the t-dna of ptic58 from agrobacterium tumefaciens as an example, techniques are described which enable recombinant plasmids to be mapped and used as hybridization probes. in all cases the starting material is a colony of cells grown on an agar plate which is then subjected to lysis by lysozyme and triton x-100 in volumes of the order of 300 microliters thus eliminating the need for handling and centrifuging liquid cultures under restrictive containment conditions. | 1979 | 233238 |
| ammonia assimilation by rhizobium cultures and bacteroids. | the enzymes involved in the assimilation of ammonia by free-living cultures of rhizobium spp. are glutamine synthetase (ec. 6.o.i.2), glutamate synthase (l-glutamine:2-oxoglutarate amino transferase) and glutamate dehydrogenase (ed i.4.i.4). under conditions of ammonia or nitrate limitation in a chemostat the assimilation of ammonia by cultures of r. leguminosarum, r. trifolii and r. japonicum proceeded via glutamine synthetase and glutamate synthase. under glucose limitation and with an excess ... | 1975 | 234505 |
| [beta-hydroxybutyrate dehydrogenase of the bacteroid rhizobium lipid]. | | 1975 | 235408 |
| induction of glutamate synthase during nodule development in lupin. | | 1975 | 237796 |
| enzymes of ammonia assimilation in rhizobium leguminosarum bacteroids. | the activities of the following enzymes were studied in connection with dinitrogen fixation in pea bacteroids: glutamine synthetase(l-glutamate: ammonia ligase (adp-forming)(ec 6.3.1.2)(gs); glutamate dehydrogenase (nadp+)(l-glutamate: nadp+ oxidoreductase (deaminating)(ec 1.4.1.4)(gdh); glutamate synthase (l-glutamine: 2-exeglutarate aminotransferase (nadph-oxidizing))(ec 2.6.1.53)(gogat). gs activity was high throughout the growth of the plant and gogat activity was always low. it is unlikely ... | 1975 | 238731 |
| adsorption and selection of rhizobia with ion-exchange papers. | ion exchange papers were used to study the adsorption of 32p-labelled rhizobia on defined surfaces. two strains of rhizobium japonicum and one each of r. leguminosarum and r. lupini were compared with escherichia coli and bacillus subtilis. the ratio of adsorption to strong and to weak acid papers/strong and weak basic papers was consistantly higher for all rhizobial strains compared to the other bacteria. the process of desorption by increasing the ion-concentration causes about 35% desorption ... | 1975 | 242293 |
| [production of soy bean inoculants. behavior of supports based on peat from tierra del fuego sterilized by vapor and ethylene oxide]. | the survival of rhizobium japonicum was studied in neutralized and sterilized peats from ushuaia and rio grande. the carriers were sterilized by ethylene oxide and by autoclaving. similar counts for rhizobium (5 x 10(8) cel/g) were obtained in peat-cultures sterilized by both methods, after eight months. a good nodulation and nitrogen fixation capacity was observed with inoculated soybean plants. using the strain rhizobium japonicum e-45, no appreciable difference in symbiotic effectiveness was ... | 1979 | 263653 |
| genetic mapping of rhizobium meliloti. | the drug resistance factor rp4, originally isolated in pseudomonas, was transferred to rhizobium meliloti. in that strain, rp4 promotes conjugational transfer of chromosomal markers to form haploid recombinants. this mating system has been used to construct a linkage map of r. meliloti. | 1977 | 266730 |
| limitations to field application of rhizobium inoculants. | | 1977 | 270342 |
| genetic engineering of nitrogen fixation (nif). | | 1977 | 270345 |
| proteins conferred by the virulence-specifying plasmid of agrobacterium tumefaciens c-58. | membrane-associated and periplasmic proteins of agrobacterium tumefaciens c-58 were compared with those from avirulent (nontumrigenic) derivative strains by slab and two-dimensional gel electrophoresis. two proteins (per-i and per-2), with a molecular weight of 37,500 and 37,300, respectively, were detected in the supernatant fraction of cells of strain c-58 treated with edta and lysozyme in which a 117-megadalton plasmid confers virulence on the organism. the same proteins are missing in an av ... | 1978 | 278990 |
| [inoculation of vicia sativa l. and medicago sativa l. with rhizobium in the soil of the colorado river in the bonarense valley]. | | 1977 | 284548 |
| autotrophic growth of h2-uptake-positive strains of rhizobium japonicum in an atmosphere supplied with hydrogen gas. | previous research from this laboratory has demonstrated co(2)-fixing and h(2)-uptake capacities of certain strains of rhizobium japonicum. in this report we have shown that sr, a h(2)-uptake-positive (hup(+)) strain of r. japonicum, is capable of autotrophic growth with h(2) as the energy source. growth occurred on mineral salts/vitamins/noble agar, mineral salts/vitamins liquid medium (0.27 mug of c as vitamins per ml), and in mineral salts liquid medium with no added vitamins when cultures wer ... | 1979 | 287019 |
| [production of inoculants leguminoses]. | | 1978 | 288116 |
| molecular cloning as a tool to the analysis of the ti plasmids of agrobacterium tumefaciens [proceedings]. | | 1978 | 289306 |
| arginine catabolism: a new function of both octopine and nopaline ti-plasmids of agrobacterium. | | 1979 | 289898 |
| quality control of commercial inoculants for legumes in uruguay (1963-1975). | | 1978 | 290009 |
| isolation of a recombination deficient agrobacterium tumefaciens mutant. | the isolation of a recombination deficient (rec-) strain of agrobacterium tumefaciens is described. strain lba 4011 was mutagenized with nitrosoguanidine and after segregation 18,000 colonies were replica plated and uv irradiated. twentytwo uv sensitive strains were isolated and tested for methylmethanesulphonate (mms) sensitivity. six of these strains were more mms-sensitive than lba 4011. a ti plasmid that was genetically marked with tn 1 (cbr) was introduced in these strains and the rescue of ... | 1979 | 290851 |
| rough and fine linkage mapping of the rhizobium meliloti chromosome. | a circular linkage map of the rhizobium meliloti chromosome, obtained from r68.45-mediated crosses, has been revised by cotransductional analysis, after general transduction by df2 phage. three short chromosomal regions have been mapped by cotransduction. comparison between conjugal and cotransductional data suggests that r68.45-mediated linkage measures are indeed rough. cotransduction seems to be a useful tool for improving the linkage map of r. meliloti. | 1979 | 290852 |
| intergeneric mobilization of rhizobium nif genes to agrobacterium and klebsiella. | | 1979 | 290853 |
| [biological fertilization (mycorrhiza + rhizobium + phosphobacteria) of trifolium pratense in different cultural conditions]. | | 1979 | 293006 |
| restriction mapping of dna of temperate rhizobium meliloti phage 16-3: comparison of genetic and physical maps indicates a long, genetically silent chromosomal arm. | the complete restriction map of dna (61.57 kb) of temperate rhizobium meliloti phage 16-3 has been constructed for enzymes bglii, hindiii, hpai, kpni, and a partial map for ecori. the strategy employed for mapping included the analysis of double, triple and partial digests; comparison of wild type and deletion mutants; and detailed analysis of subfragments, exploiting the presence of cohesive ends of the phage. comparison of the genetic and physical maps indicates that one arm of the chromosome ... | 1979 | 293461 |
| tetrahydrofolate-dependent biosynthesis of ribothymidine in transfer ribonucleic acids of gram-positive bacteria. | trimethoprim, an inhibitor that prevents tetrahydrofolate-dependent transmethylation reactions inbacteria, was used in a comparative study to discriminate between two possible biosynthetic pathways, either the s-adenosylmethionine or the tetrahydrofolate-dependent formation of ribothymidine (rt) in transfer ribonucleic acids (trna's) of several strains of gram-positive and gram-negative microorganisms. rt-deficient trna's accumulate in trimethoprim-treated gram-positive streptococcus faecium, st ... | 1977 | 318638 |
| introduction of bacteriophage mu into pseudomonas solanacearum and rhizobium meliloti using the r factor rp4. | phage mu-1 and a thermoinducible derivative, mu-1 cts 62 were inserted into the broad host range r factor rp4. these hybrid plasmids were transferred by conjugation to a phytopathogenic bacterium pseudomonas solanacearum gmi 1000 and a legume-root nodule bacterium rhizobium meliloti 2011. the mu genome is transcribed and tranlated in these new hosts: p. solanacearum (rp4:mu cts) cultures have a spontaneous production of about 5 x 10(5) plaque-forming units ml-1 which is similar to the frequency ... | 1977 | 319201 |
| replica-plating virulence assay for agrobacterium tumefaciens. | replica plating onto wounded tobacco leaves provides a convenient method for screening for avirulent mutants of agrobacterium tumefaciens. | 1977 | 330393 |
| effect of dimethyl sulphoxide on the expression of nitrogen fixation in bacteria. | storage in dimethyl sulphoxide (dmso) of escherichia coli k12 hybrids carrying nif+ genes from klebsiella pneumoniae can result in selection of a defective nitrogen-fixing phenotype. similar results are obtained with e. coli k12 hybrids containing the nitrogen-fixing capacity from rhizobium trifolii. dmso appears to affect particular inner membrane proteins associated with energy metabolism in e. coli k12 and four chromosomal regions (chld, chlg, his and unc) are associated with resistance to dm ... | 1977 | 332135 |
| flow-microfluorometric analysis of escherichia coli, rhizobium meliloti, and rhizobium japonicum at different stages of the growth cycle. | the applicability of flow-microfluorometry (fmf) to the study of bacterial samples was investigated on cultures of rhizobium meliloti, rhizobium japonicum, and escherichia coli using fluorescent and light-scattering signals. this technique which analyzes individual bacterial cells in a population was used to monitor the relative change in nucleic acid content and cell size during the growth cycle of the three microorganisms which were known to have different growth rates. early log-phase e. coli ... | 1977 | 332295 |
| bacterial phytotoxins. | representatives of all of the major genera of plant disease-causing bacteria have been shown to produce one or more phytotoxins. toxicological studies on the bacterial diseases of the major food crops have not been extensive. bacterial phytotoxins belong to a number of classes of organic substances, including peptide, derivatized amino acid, polysaccharide, and glycopeptide. the mechanism of action of these compounds is largely unknown, as is their origin and importance in the disease syndrome. ... | 1977 | 334039 |
| the ti-plasmid of agrobacterium tumefaciens, a natural vector for the introduction of nif genes in plants? | | 1977 | 336023 |
| use of rp4 plasmids carrying bacteriophage mu insertions in nitrogen fixing bacteria klebsiella pneumoniae and rhizobium meliloti. | | 1977 | 336028 |
| viability of rhizobium bacteroids. | bacteroids prepared from nodules of soybean and bean were tested for viability. contrary to the prevailing view that bacteroids are nonviable, it was found that bacteroids averaged 90% viability, irrespective of rhizobium strain, nodule age, or nodule environment. | 1977 | 339840 |
| transfer of nitrogen fixation genes from a bacterium with the characteristics of both rhizobium and agrobacterium. | strain t1k, reported to be rhizobium trifolii strain t1 carrying the drug resistance plasmid ru-1drd, was able to transfer a cluster of nif+ genes to escherichia coli k-12. additional genetic material, resembling the gal-chla region of e. coli, was also transferred from strain t1k. the segregation pattern of these transferred genes suggested that they were on a plasmid. although strain tik was able to nodulate red and white clover, it also formed very slow-growing galls on tomato stems and share ... | 1978 | 342496 |
| incorporation and maintenance of recombinant-dna plasmid vehicles pbr313 and pcr1 in plant protoplasts. | | 1978 | 344069 |
| transfection and transformation of agrobacterium tumefaciens. | the freeze thaw transfection procedure of dityatkin et al. (1972) was adapted for the transfection and transformation of a. tumefaciens. transfection of the strains b6s3 and b6-6 with dna of the temperate phage ps8cc186 yielded a maximum frequency of 2 10(-7) transfectants per total recipient population. in transformation of the strain gv3100 with the p type plasmid rp4 a maximum frequency of 3.5 10(-7) transformants per total recipient population was obtained. agrobacterium ti-plasmids were int ... | 1978 | 355847 |
| [the classification of agrobacterium and rhizobium phages (author's transl)]. | all phages studied are tailed, belong to six morphological groups, and are classified by morphological and serological properties and by physico-chemical parameters of the virion and its nucleic acid. four species of agrobacterium and 12 species of rhizobium phages are described, and their relationship with enterobacteria phages discussed. they include 68 viruses, whereas 60 poorly known phages have not been classified. | 1978 | 370746 |
| transfer of rp4::mu plasmids to agrobacterium tumefaciens. | | 1978 | 372975 |
| spontaneous formation of cointegrates of the oncogenic ti-plasmid and the wide-host-range p-plasmid rp4. | | 1978 | 372976 |
| some aspects of fermentation of rhizobium leguminosarum with reference to economy of ingredients in the substrate. | incremental feeding of nutrients was found to be beneficial in mass cultivation of r. leguminosarum. similarly, semi-continuous fermentation of r. leguminosarum up to 4 days was also found to be useful in maintaining the viable number of cells. | 1978 | 373307 |
| expression of escherichia coli tryptophan operon in rhizobium leguminosarum. | rp4-trp hybrid plasmid containing escherichia coli whole tryptophan operon was conjugatively transferred from e. coli to rhizobium leguminosarum strains carrying mutations in different trp genes, converting their trp- phenotype to trp+. that the phenotype change of the r. leguminosarum cells was due to the presence of the e. coli tryptophan operon was verified by the isolation of rp4-trp hybrid plasmid from the r. leguminosarum conjugant cells, and by re-transfer of rp4-trp plasmid by conjugatio ... | 1979 | 375025 |
| crown-gall and agrobacterium tumefaciens: survey of a plant-cell-transformation system of interest to medicine and agriculture. | | 1979 | 377583 |
| transcription of ti plasmid-derived sequences in three octopine-type crown gall tumor lines. | total rna isolated from three octopine-type crown gall lines contains sequences homologous to specific regions of the tumor-inducing (ti) plasmid of agrobacterium tumefaciens strain 15955. a comparison of transcripts in these three tumor lines suggests that tumor cells transcribe various sequences within a sector of plasmid dna of 13 x 10(6) daltons and that transcription may not be uniform across the plasmid derived sequences (t-dna). transcription of t-dna by octopine-type tumors occurs at fou ... | 1979 | 379864 |
| use of rp4-prime plasmids constructed in vitro to promote a polarized transfer of the chromosome in escherichia coli and rhizobium meliloti. | rp4-prime plasmids containing chromosomal fragments of either escherichia coli or rhizobium meliloti were constructed in vitro. when introduced into e. coli or r. meliloti respectively, they promoted a polarized transfer of the chromosome as demonstrated either by the gradient of transfer of various markers or by the study of the genetic constitution of recombinants. in e. coli, mobilization was shown to be dependent upon the presence of a functional rec a system. inheritance of markers was due ... | 1979 | 384151 |
| initiation of plant root-microbe interactions. | | 1979 | 386926 |
| host dependence of rp1-specified resistance to ampicillin: differential expression in escherichia coli and rhizobium leguminosarum. | rhizobium leguminosarum l4 is able to serve as a host for the plasmid rp1. properties of r. leguminosarum [rp1] plasmid carrier suggest that the expression of rp1-coded apr gene(s) is inhibited in this host, although the determinants of transfer and resistance to kanamycin and tetracycline are expressed. this system exemplifies a differential expression of plasmid genes in a new host. | 1979 | 391648 |
| environmental factors influencing nitrate respiration in escherichia coli k12 and rhizobium trifolii. | the nitrate respiratory systems of both the facultative anaerobe escherichia coli k12 strain w3350 and the aerobe rhizobium trifolii strain t1 are regulated in a similar manner by a complex set of interactions involving h2, n2, co2, glucose and nitrate. in addition, the nitrate respiratory system of strain t1 can be regulated by chlorate. a possible mechanism is presented to illustrate how these complex interactions might take place. | 1979 | 393958 |
| uptake of foreign genetic material by plant protoplasts. | | 1977 | 402328 |
| [demonstration of 2 enzymes with beta-galactosidase activity in rhizobium meliloti]. | the beta-galactosidase (ec 3.2.1.23) activities of wild-type rhizobium meliloti and its lactose slow-hydrolyzing mutant have been compared. the properties of the enzyme are very different in each strain. these differences allow us to prove that two enzymes with a beta-galactosidase activity can be found in the wild-type whereas only one enzyme remains in the mutant strain. | 1977 | 409467 |
| introduction of potential sex factors into rhizobium japonicum. | | 1977 | 411474 |
| antibiotic resistance in rhizobium japonicum: implications for safety and interpretation of nif transfer from rhizobium. | | 1977 | 411475 |
| overview of nitrogen fixation. | | 1977 | 411477 |
| [role of free-living nitrogen fixers in the nitrogen balance of soils]. | | 1977 | 415216 |
| electron microscopy and computerized evaluation of some partially denatured group p resistance plasmids. | dna of the r plasmids rp1, rp4 and rp8 was isolated from various hosts. the lengths of these plasmid molecules were determined by electron microscopy: rp1 and rp4 were about 19 micron long, rp8 measured 31 micron. an rp4 plasmid mutant, designated rp4a, was isolated from escherichai coli; it was about 1 micron shorter than normal rp4 dna. to investigate the molecular relationship between rp4, rp4a and rp8 dnas of these plasmids were partially denatured and examined in the electron microscope. me ... | 1978 | 416173 |
| tumor induction by agrobacterium tumefaciens prevented in vigna sinensis seedlings systemically infected by ribonucleic acid viruses. | cowpea (vigna sinensis) seedlings failed to develop tumors after being inoculated with crown gall bacteria (agrobacterium tumefaciens) if, at times earlier than 1 day later, they were inoculated on the primary leaves with a cowpea mosaic virus that systemically infects them. inoculation with buffer or with a virus that is restricted to a localized infection, or to which the cowpea is immune, did not interfere with the subsequent development of tumors. the virus infection did not appear to affect ... | 1979 | 422243 |
| crown gall teratoma formation is plasmid and plant controlled. | experiments using different species of the plant nicotiana and strains of the bacterium agrobacterium tumefaciens showed that teratoma formation from crown galls was dependent on the combination of bacterial ti plasmid and host plant used. | 1979 | 422509 |
| regulation of hydrogenase in rhizobium japonicum. | factors that regulate the expression of an h2 uptake system in free-living cultures of rhizobium japonicum have been investigated. rapid rates of h2 uptake by r. japonicum were obtained by incubation of cell suspensions in a mg-phosphate buffer under a gas phase of 86.7% n2, 8.3% h2, 4.2% co2, and 0.8% o2. cultures incubated under conditions comparable with those above, with the exception that ar replaced h2, showed no hydrogenase activity. when h2 was removed after initiation of hydrogenase der ... | 1979 | 422513 |
| hydrogenase system in legume nodules: a mechanism of providing nitrogenase with energy and protection from oxygen damage. | | 1979 | 426786 |
| fatty acid composition of rhizobium spp. | the fatty acid composition of 42 isolates belonging to the major plant affinity groups of rhizobium has been determined and found to vary reproducible with culture age. numerical taxonomic techniques applied to the 15 major fatty acid components of log-phase cultures of comparable physiological age showed that the rhizobia constitute a uniform group. however, two clusters comprising soybean-cowpea isolates and pea-bean isolates were evident. these observations, based on a simple analysis of only ... | 1979 | 427657 |
| [lysogeny of rhizobium japonicum and the sensitivity of these cultures to phages isolated from soil]. | twenty cultures of rhizobium japonicum of various origin were tested for lysogeny using a cross technique with a preliminary uv induction and without it as well as by electron microscopy. none of the cultures was found in the lysogenic state. phages active against rh. japonicum were detected in four soil samples on which soybean plants were grown; 27 phages were isolated by the enrichment method and 3 phages without enrichment. the phages were capable of lysis of only rh. japonicum cultures and ... | 1979 | 440166 |
| [deformation of lucerne root hairs caused by the growth substances and culture broth filtrates of rhizobium meliloti]. | deformation of lucerne root hairs caused by the action of beta-indolylacetic acid (iaa) and alpha-naphthylacetic acid (naa) differs from deformation induced by rhizobium meliloti. high concentrations of iaa brought about abnormal deformation of root hairs wherease the action of average concentrations of iaa resulted in corkscrew-like winding and wavy structures. no deformation was observed under the action of low iaa concentrations or the cultural broth of rhizobium. infective filaments in root ... | 1979 | 440167 |
| transcription in nuclei isolated from tobacco tissues. | | 1979 | 446760 |
| development of the nitrogen-fixing and protein-synthesizing apparatus of bacteroids in pea root nodules. | some aspects of root nodule development of pisum sativum inoculated with rhizobium leguminosarum were examined. 1. nitrogenase activity (measured as acetylene reduction) appears to be preceded by leghemoglobin synthesis (measured immunologically). 2. syntheses of component i and component ii of nitrogenase are not strictly coordinated. synthesis of component i starts before component ii. 3. plant and bacteroid protein synthesis (measured by [35s]sulfate labeling) in root nodules declines rapidly ... | 1979 | 454614 |
| isolation of a non-tumor-inducing mutant of the ti plasmid of agrobacterium tumefaciens strain b6. | a nonpathogenic mutant of agrobacterium tumefaciens strain b6 was isolated and its properties compared with the parental strain in an effort to localize the mutation. both b6 and its mutant (b6-95) had similar colony color and morphology, were ketolactose positive, utilized octopine, and contained plasmid dna. kinetic analysis of dna reannealing showed that total dna homology and plasmid dna homology between b6 and b6-95 was at least 90%. the length of both plasmids was found to be 58 micrometer ... | 1979 | 455147 |
| phenotypic reversion of nitrogenase in pleiotropic mutants of rhizobium meliloti. | in two out of three pleiotropic mutants of rhizobium meliloti, defective in nitrate reductase induced by amino acid utilization in vegetative bacteria and in symbiotic nitrogen fixation, nitrogenase activity could be restored completely by purines and partially by the amino acids l-glutamate, l-aspartate, l-glutamine, and l-asparagine. the compounds restoring effectiveness in nitrogen fixation did not restore nitrate reductase activity in vegetative bacteria. the restoration of effectiveness sup ... | 1979 | 455148 |
| nitrogen fixation by rhizobium sp. 32h1. a morphological and ultrastructural comparison of asymbiotic and symbiotic nitrogen-fixing forms. | the induction of nitrogenase (c2h2) activity in asymbiotically cultured rhizobium sp. 32h1 was found to be associated with morphological changes in the cells which were more pronounced than those seen in bacteroids. polyphosphate granules were found in both bacteroids and cultured cells, but poly-beta-hydroxybutyrate vesicles were almost absent in bacteroids but were present in cultured cells. freeze-etching techniques revealed no differences between the asymbiotically cultured nitrogen-fixing f ... | 1979 | 455150 |
| genetic mapping of the bacteriophage ps8 of agrobacterium tumefaciens. | genetic mapping of the chromosome of the bacteriophage ps8 of agrobacterium tumefaciens using temperature sensitive (ts) mutants of the bacteriophage is described. | 1979 | 456950 |
| r-plasmid-mediated chromosomal gene transfer in agrobacterium tumefaciens. | although several techniques are available for transferring the ti plasmids from one strain of agrobacterium tumefaciens to another, there are no reproducible methods for analysis of chromosomal markers in this phytopathogen. the r plasmid, r68.45, is known to show chromosomal mobilizing ability in several bacterial genera including the closely related rhizobia. r68.45 was transferred into the prototrophic a. tumefaciens strain 15955. ten kanamycin-resistant transconjugant clones were tested for ... | 1979 | 457601 |
| general transduction in rhizobium meliloti by a thermosensitive mutant of bacteriophage df2. | a simiplified version of bacteriophage df2 transduction, using the thermosensitive mutant df2tsc, is described. the transduction frequencies of rhizobium meliloti markers by df1tsc are of about 10(-6) or higher. the development of transductants at 34 degrees c does not require the addition of antiserum for phage neutralization. | 1979 | 457604 |
| negative control of octopine degradation and transfer genes of octopine ti plasmids in agrobacterium tumefaciens. | the regulatory system that controls the expression of the ti plasmid-borne octopine degradation (uad) and transfer (tra) genes in agrobacterium tumefaciens was studied. a deletion mutant derived from the cointegrate plasmid r702::ti-b6s3 was isolated, which was compatible with a wild-type ti plasmid and which had retained the uad genes. by means of this mutant plasmid pal116, it was possible to make cells diploid for the uad genes. pal116 was introduced into rec- strains that contained different ... | 1979 | 457610 |
| host range conferred by the virulence-specifying plasmid of agrobacterium tumefaciens. | the host range of agrobacterium tumefaciens 1d1109, known to induce crown gall only on grapevine (vitis spp.), was extended to include many plant species by transferring a tumor-inducing plasmid (pti) from strain 1d1, a broad-host-range pathogen. the pti plasmid was mobilized by the conjugative plasmid prk2, which was inserted into 1d1 by mating with escherichia coli j53(prk2). the resulting transconjugants were screened for their ability to induce crown gall tumors on hosts other than grapevine ... | 1979 | 457613 |
| the involvement of the membrane potential in nitrogen fixation by bacteroids of rhizobium leguminosarum. | | 1979 | 467678 |
| effect of bacterial polysaccharides on the growth of gaeumannomyces graminis var. tritici and wheat roots. | agrobacterium sp. and related species which in the soil and in the rhizosphere of wheat accompany the fungus gaemannomyces graminis var. tritici and cause take-all of the wheat roots produced polysaccharides in pure cultures (glucans, mannoglucans and galactomannoglucans). these polysaccharides were utilized better by the mycelium of g. graminis than glucose and polysaccharides of plant origin that occurred on the surface of wheat roots (the so-called mucigel). at lower concentrations these bact ... | 1979 | 468081 |
| choriogonadotropin-like antigen in an anaerobic bacterium, eubacterium lentum, isolated from a rectal tumor. | using the indirect fluorescein-labeled and indirect peroxidase-antiperoxidase-labeled immunohistochemical techniques, and utilizing both antiserum specific for the beta-subunit of choriogonadotropin and antiserum for the total hormone, we have demonstrated the presence of a choriogonadotropin-like immunoreactive material in a strain of eubacterium lenthum that was originally isolated from a rectal tumor. in contrast, both immunohistochemical reactions were negative when applied to a strain of co ... | 1979 | 468380 |
| [nitrogen fixing activity of pea nodule bacteria during different phases of host plant development]. | the activity of nitrogenase in nodules of pea plants and the rate of diurnal nitrogen fixation were studied at different phases of the plant growth using the acetylene and isotope techniques. at the same time, the morphology of nodule bacteria was studied by electron and phase-contrast microscopy. about 90% of the bacteria in nodules were found in the form of bacteroids from the early phase of the plant growth (budding) to ripening when gemmated arthrospores could be observed on some bacteroids. ... | 1979 | 470633 |