Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| physical analysis of pb2, a temperate bacteriophage of agrobacterium tumefaciens. | we have constructed a detailed physical map of pb2, a temperate bacteriophage of agrobacterium tumefaciens. the restriction endonucleases bam hi (3 sites), eco ri (22 sites), hind iii (19 sites), hpa i (5 sites), xba i (1 site), and xho i (1 site) were used to elucidate the map of infectious pb2 dna. the map was generated by reciprocal sequential digestions and analysis of partial digestion products of isolated restriction fragments. we have determined the genome size as 66.35 +/- 1.71 kb. the p ... | 1987 | 2824148 |
| identification and characterization of the rhizobium meliloti ntrc gene: r. meliloti has separate regulatory pathways for activation of nitrogen fixation genes in free-living and symbiotic cells. | we show here that rhizobium meliloti, the nitrogen-fixing endosymbiont of alfalfa (medicago sativa), has a regulatory gene that is structurally homologous to previously characterized ntrc genes in enteric bacteria. dna sequence analysis showed that r. meliloti ntrc is homologous to previously sequenced ntrc genes from klebsiella pneumoniae and bradyrhizobium sp. (parasponia) and that an ntrb-like gene is situated directly upstream from r. meliloti ntrc. similar to its counterparts in k. pneumoni ... | 1987 | 2881918 |
| tight linkage of glna and a putative regulatory gene in rhizobium leguminosarum. | rhizobium leguminosarum, biovar viceae, strain rcc1001 contains two glutamine synthetase activities, gsi and gsii. we report here the identification of glna, the structural gene for gsi. a 2 kb fragment of dna was shown to complement the gln- phenotype of klebsiella pneumoniae glna mutant strains. dna sequence analysis revealed an open reading frame (orf) of 469 codons specifying a polypeptide of 52,040 daltons. its deduced amino acid sequence was found to be highly homologous to other glutamine ... | 1987 | 2882467 |
| glutamine synthetase genes of pea encode distinct polypeptides which are differentially expressed in leaves, roots and nodules. | we have characterized the distinct polypeptides, primary translation products and mrnas encoding glutamine synthetase (gs) in the various organs of pea. western blot analysis of soluble protein has identified five distinct gs polypeptides which are expressed at different relative levels in leaves, roots and nodules of pea. of the two gs polypeptides in leaves (44 and 38 kd), the 44-kd gs polypeptide is predominant and is localized to the chloroplast stroma. in roots, the predominant gs polypepti ... | 1987 | 2884100 |
| processing of the t-dna of agrobacterium tumefaciens generates border nicks and linear, single-stranded t-dna. | transfer and integration of a defined region (t-dna) of the tumor-inducing (ti) plasmid of agrobacterium tumefaciens is essential for tumor formation. we used a physical assay to study structural changes induced in agrobacterium t-dna by cocultivation with plant cells. we show that nicks are introduced at unique, identical locations in each of the 24-base-pair imperfect direct repeats which flank the t-dna and present evidence that a linear, single-stranded molecule is generated. we propose that ... | 1987 | 3029014 |
| conservation of structure and location of rhizobium meliloti and klebsiella pneumoniae nifb genes. | using transposon tn5-mediated mutagenesis, an essential rhizobium meliloti nitrogen fixation (nif) gene was identified and located directly downstream of the regulatory gene nifa. maxicell and dna sequence analysis demonstrated that the new gene is transcribed in the same direction as nifa and codes for a 54-kilodalton protein. in klebsiella pneumoniae, the nifbq operon is located directly downstream of a gene which is structurally and functionally homologous to the r. meliloti nifa gene. the dn ... | 1987 | 3029020 |
| genetic and structural analysis of the rhizobium meliloti fixa, fixb, fixc, and fixx genes. | the fixa, fixb, fixc, and fixx genes of rhizobium meliloti 1021 constitute an operon and are required for nitrogen fixation in alfalfa nodules. dna homologous to the r. meliloti fixabc genes is present in all other rhizobium and bradyrhizobium species examined, but fixabc-homologous sequences were found in only one free-living diazotroph, azotobacter vinelandii. to determine whether the fixabcx genes share sequence homology with any of the 17 klebsiella pneumoniae nif genes, we determined the en ... | 1987 | 3029021 |
| alteration of surface properties in a tn5 mutant strain of rhizobium trifolii 0403. | a symbiotically defective mutant strain of rhizobium trifolii, ur251, was obtained by transposon tn5 mutagenesis of r. trifolii 0403 rif and recognized by its partially ineffective (fix +/-) phenotype on white clover plants. ur251 had a single tn5 insertion in plasmid dna, a wild-type plasmid pattern, and no detectable mu dna sequences originally present in the vector used for tn5 mutagenesis. agglutination by the clover lectin trifoliin a and attachment to clover root hairs was higher with ur25 ... | 1987 | 3029022 |
| organization and partial sequence of a dna region of the rhizobium leguminosarum symbiotic plasmid prl6ji containing the genes fixabc, nifa, nifb and a novel open reading frame. | by hybridization and heteroduplex studies the fixabc and nifa genes of the rhizobium leguminosarum symbiotic plasmid prl6ji have been identified. dna sequencing of the region containing nifa showed an open reading frame of 1557 bp encoding a protein of 56, 178 d. based on sequence homology, this orf was confirmed to correspond to the nifa gene. comparison of three nifa proteins (klebsiella pneumoniae, rhizobium meliloti, rhizobium leguminosarum) revealed only a weak relationship in their n-termi ... | 1987 | 3029674 |
| universal chemical assay for the detection and determination of siderophores. | a universal method to detect and determine siderophores was developed by using their high affinity for iron(iii). the ternary complex chrome azurol s/iron(iii)/hexadecyltrimethylammonium bromide, with an extinction coefficient of approximately 100,000 m-1 cm-1 at 630 nm, serves as an indicator. when a strong chelator removes the iron from the dye, its color turns from blue to orange. because of the high sensitivity, determination of siderophores in solution and their characterization by paper el ... | 1987 | 2952030 |
| studies on the introduction and mobility of the maize activator element in arabidopsis thaliana and daucus carota. | we have co-transformed carrot (daucus carota) and arabidopsis thaliana with an agrobacterium tumefaciens non-tumorigenic t-dna carrying the maize transposable element activator (ac) and an agrobacterium rhizogenes ri t-dna. we present evidence that the ac element transposes in transformed root or root-derived callus cultures of both species. we show that fertile plants can be regenerated from transformed, root-derived callus cultures of arabidopsis, demonstrating the utility of the ri plasmid fo ... | 1987 | 2832144 |
| klebsiella pneumoniae nif-lac fusions are expressed in agrobacterium tumefaciens c58. | plasmids containing hybrid genes, in which different klebsiella pneumoniae nif (nitrogen-fixation) promoters were fused with the structural part of the escherichia coli lac operon, were introduced into a double auxotrophic derivative of agrobacterium tumefaciens c58. a study of their expression in the new host was made simple by the inherent inability of a. tumefaciens c58 to produce beta-galactosidase unless provided with the wild-type lac operon of e. coli. as shown by quantitative measurement ... | 1987 | 3108628 |
| visual assays of transformation in plant cells. | we discuss the utility of visual assays for the expression of genes introduced into plant cells. such assays are valuable for both transient and stable gene expression studies. we review the properties of three visual assays that are already in use or under development phase for maize and other cereal crops. these assays depend on the expression of beta-galactosidase, luciferase, or structural genes required for anthocyanin pigment biosynthesis. | 1987 | 3109371 |
| expression vectors based on the agrobacterium rhizogenes ri plasmid transformation system. | this article describes several new expression vectors that capitalize on the ability of agrobacterium rhizogenes to transfer dna from its ri plasmid to the plant nuclear genome. the intermediate vectors described include an expression cassette based on one of the three following promoters: the nopaline synthase promoter, or the cauliflower mosaic virus (camv) promoters responsible for transcription of either the 19s or 35s camv rna. the termination and polyadenylation signals are either from the ... | 1987 | 3111548 |
| genetic analysis of mannityl opine catabolism in octopine-type agrobacterium tumefaciens strain 15955. | the genetic organization of functions responsible for mannityl opine catabolism of the ti plasmid of agrobacterium tumefaciens strain 1,5955 was investigated. a partial hindiii digest of pti1,5955 was cloned into a broad host range cosmid and the clones obtained were tested for ability to confer mannityl opine degradation upon agrobacterium. inserts containing genes for catabolism of mannopinic acid, mannopine, agropine, and agropinic acid were obtained, spanning a segment of 43 kb on the ti pla ... | 1987 | 3112522 |
| microbes in or near field-testing. | 1987 | 3114880 | |
| analysis of lectin binding by bradyrhizobium japonicum strains grown on nitrocellulose filters using peroxidase-labeled lectin. | a procedure was developed to assess the ability of wild-type and mutant strains of bradyrhizobium japonicum to bind soybean lectin. the lectin-binding ability of bacteria grown on nitrocellulose filters was determined using peroxidase-labeled soybean lectin. the assay produced clear differences between strains known to be unable to bind soybean lectin and those which can. the assay gave results identical to those of the fluorescein isothiocyanate-soybean lectin-binding assay of t. v. bhuvaneswar ... | 1987 | 3118739 |
| rhizobium meliloti insertion element isrm2 and its use for identification of the fixx gene. | two of the three plasmids of the wild-type rhizobium meliloti 41 (prme41a and prme41c) carry a copy of isrm2, a 2.7-kilobase-long transposable element. isrm2 is terminated by 22-base-pair (bp) inverted repeat sequences, exhibiting some homology to the inverted repeats of elements generating 9-bp target sequence duplication. transposition of isrm2 results in a duplication of 8 bp in length, rather rare among transposable elements. dna sequences homologous to an internal fragment of isrm2 were fou ... | 1987 | 3031010 |
| isolation and characterization of symbiotic mutants of bradyrhizobium sp. (arachis) strain nc92: mutants with host-specific defects in nodulation and nitrogen fixation. | random transposon tn5 mutagenesis of bradyrhizobium sp. (arachis) strain nc92, a member of the cowpea cross-inoculation group, was carried out, and kanamycin-resistant transconjugants were tested for their symbiotic phenotype on three host plants: groundnut, siratro, and pigeonpea. two nodulation (nod- phenotype) mutants were isolated. one is unable to nodulate all three hosts and appears to contain an insertion in one of the common nodulation genes (nodabcd); the other is a host-specific nodula ... | 1987 | 3032910 |
| transcription of rhizobium meliloti nodulation genes. identification of a nodd transcription initiation site in vitro and in vivo. | nodulation genes in rhizobium are required for invasion of the host plant. the nodabc operon is induced by plant activator molecules; this activation requires the gene product of the constitutively expressed nodd locus, which is transcribed divergently from nodabc. we are employing in vitro transcription to elucidate the molecular mechanism of nod gene activation. we used a micropurification technique to obtain rna polymerase from rhizobium meliloti, and here demonstrate that it initiated and te ... | 1987 | 3032978 |
| physical characterization of rhizobium meliloti megaplasmids. | intact megaplasmids of rhizobium meliloti 2011 have been isolated and visualized by electron microscopy. the contour lengths of 64 megaplasmid molecules were determined. one definite class of molecules of 400 micron length and a range of larger molecules with lengths of up to 560 micron was observed. the contour lengths of the megaplasmids prme2011a and prme2011b were measured after isolation from plasmid-free agrobacterium strains into which they had been individually transferred. plasmid prme2 ... | 1987 | 3033717 |
| rhizobium meliloti ntra (rpon) gene is required for diverse metabolic functions. | we report the identification and cloning of an ntra-like (glnf rpon) gene of rhizobium meliloti and show that the r. meliloti ntra product (ntra) is required for c4-dicarboxylate transport as well as for nitrate assimilation and symbiotic nitrogen fixation. dna sequence analysis showed that r. meliloti ntra is 38% homologous with klebsiella pneumoniae ntra. subcloning and complementation analysis suggested that the r. meliloti ntra promoter lies within 125 base pairs of the initiation codon and ... | 1987 | 3034856 |
| transposon-induced symbiotic mutants of bradyrhizobium japonicum: isolation of two gene regions essential for nodulation. | two strains of the soybean endosymbiont bradyrhizobium japonicum, usda 110 and 61 a101 c, were mutagenized with transposon tn5. after plant infection tests of a total of 6,926 kanamycin and streptomycin resistant transconjugants, 25 mutants were identified that are defective in nodule formation (nod-) or nitrogen fixation (fix-). seven nod- mutants were isolated from strain usda110 and from strain 61 a101 c, 4 nod- mutants and 14 fix- mutants were identified. subsequent auxotrophic tests on thes ... | 1987 | 3037278 |
| interposon mutagenesis of soil and water bacteria: a family of dna fragments designed for in vitro insertional mutagenesis of gram-negative bacteria. | we have constructed a series of derivatives of the omega interposon [prentki and krisch, gene 29 (1984) 303-313] that can be used for in vitro insertional mutagenesis. each of these dna fragments carries a different antibiotic or hg2+ resistance gene (apr, cmr, tcr, kmr or hgr) which is flanked, in inverted orientation, by transcription and translation termination signals and by synthetic polylinkers. the dna of these interposons can be easily purified and then inserted, by in vitro ligation, in ... | 1987 | 3038679 |
| deletion analysis of the mannopine synthase gene promoter in sunflower crown gall tumors and agrobacterium tumefaciens. | we have used deletion mutagenesis to analyze a tr-dna promoter from the octopine-type ti plasmid ptib6806. the promoter for the gene encoding mannopine synthase (mas) was cloned upstream of the bacterial kanamycin-resistance gene neomycin phosphotransferase ii (npt ii). bal31 deletion mutagenesis was used to generate deletion derivatives of the mas/nptii gene beginning 1353 bp upstream of the initiation of transcription and extending to 120 bp downstream from the mrna start site. deletions that ... | 1987 | 3039293 |
| the noc region of ti plasmid c58 codes for arginase and ornithine cyclodeaminase. | plant tumors induced by agrobacterium tumefaciens synthesize a group of substances (opines) which can serve as sole source of carbon and nitrogen for the bacteria. we investigate ti-plasmid-coded genes and enzymes involved in catabolism of the opine n2-(1,3-dicarboxypropyl)-l-arginine (nopaline) with a novel approach: expression and mapping of protein-coding regions in escherichia coli minicells, followed by identification of enzyme functions in the heterologous e. coli background. the results s ... | 1987 | 3040404 |
| cell surface polysaccharides from bradyrhizobium japonicum and a nonnodulating mutant. | the cell surface polysaccharides of wild-type bradyrhizobium japonicum usda 110 and a nonnodulating mutant, strain hs123, were analyzed. the capsular polysaccharide (cps) and exopolysaccharide (eps) of the wild type and the mutant strain do not differ in their sugar composition. cps and eps are composed of mannose, 4-o-methylgalactose/galactose, glucose, and galacturonic acid in a ratio of 1:1:2:1, respectively. h nuclear magnetic resonance spectra of the eps and cps of the wild type and mutant ... | 1987 | 3793715 |
| cloning of rhizobium leguminosarum genes for competitive nodulation blocking on peas. | one type of competitive interaction among rhizobia is that between nonnodulating and nodulating strains of rhizobium leguminosarum on primitive pea genotypes. pisum sativum cv. afghanistan nodulates effectively with r. leguminosarum tom, and this can be blocked in mixed inoculations by r. leguminosarum pf2, which does not nodulate this cultivar. we termed this pf2 phenotype cnb+, for competitive nodulation blocking. strain pf2 contains three large plasmids including a 250-kilobase-pair symbiotic ... | 1987 | 3546272 |
| characterization of the vire operon of the agrobacterium ti plasmid ptia6. | the agrobacterium tumefaciens ti plasmid contains at least six transcriptional units (designated vir loci) which are essential for efficient crown gall tumorigenesis. mutations in one of these loci, vire, result in a sharply attenuated virulence phenotype. in the present communication, we have analyzed the vire operon at the molecular level. this locus contains open reading frames coding for two hydrophilic proteins having molecular weights of approximately 7,000 daltons and 60,500 daltons. usin ... | 1987 | 3547330 |
| characterization of the vire locus of agrobacterium tumefaciens plasmid ptic58. | the vire locus that is responsible for the efficiency of infection by agrobacterium tumefaciens (t. hirooka and c. kado, j. bacteriol. 168:237-243, 1986) is located next to the right boundary of the virulence (vir) region of the nopaline plasmid ptic58. this locus is very similar to the vire locus of octopine type ti plasmids on the basis of nucleotide and amino acid sequence comparisons as well as genetic complementation analyses. the nucleotide sequence of vire revealed three open reading fram ... | 1987 | 3549694 |
| [hybridization of dna from actinomycetes of the genus frankia with nitrogenase structural genes (nifhdk) of klebsiella pneumoniae and nod-genes of rhizobium melioti]. | dna sequence homology with the plasmid psa30 carrying the cloned nifhdk genes from klebsiella pneumoniae was revealed in ten frankia spp. strains, nitrogen-fixing symbionts of non-legumes, irrespective of the strain phenotype (nod+fix+, nod+ fix- or nod- fix?). none of the frankia spp. dnas exhibited homology with the plasmid prmsl26 harbouring the rhizobium meliloti nod-genes encoding for early symbiotic functions. | 1987 | 3553912 |
| agrobacterium tumefaciens-mediated transformation of the monocot genus gladiolus: detection of expression of t-dna-encoded genes. | agrobacterium tumefaciens was capable of directing the transformation of gladiolus sp., a monocot genus belonging to the family iridaceae. only strains capable of transferring t-dna formed tumors, sections of which could be cultured in phytohormone-free media. opine synthase activities were also observed in homogenates made from these tumors. | 1987 | 3558323 |
| a gene upstream of the rhizobium trifolii nifa gene encodes a ferredoxin-like protein. | 1987 | 3562251 | |
| common loci for agrobacterium tumefaciens and rhizobium meliloti exopolysaccharide synthesis and their roles in plant interactions. | mutants of rhizobium meliloti have been isolated which are deficient in exopolysaccharide (eps) production and effective nodulation of alfalfa (j. a. leigh, e. r. signer, and g. c. walker, proc. natl. acad. sci. usa 82:6231-6235, 1985). we isolated approximately 100 analogous eps-deficient (exo) mutants of the closely related plant pathogen agrobacterium tumefaciens, including strains whose eps deficiencies were specifically complemented by each of five cloned r. meliloti exo loci. we also clone ... | 1987 | 3571162 |
| a new symbiotic cluster on the psym megaplasmid of rhizobium meliloti 2011 carries a functional fix gene repeat and a nod locus. | a 290-kilobase (kb) region of the rhizobium meliloti 2011 psym megaplasmid, which contains nodulation genes (nod) as well as genes involved in nitrogen fixation (nif and fix), was shown to carry at least six sequences repeated elsewhere in the genome. one of these reiterated sequences, about 5 kb in size, had previously been identified as part of a cluster of fix genes located 220 kb downstream of the nifhdk promoter. deletion of the reiterated part of this fix cluster does not alter the symbiot ... | 1987 | 3571166 |
| molecular characterization of the virc genes of the ti plasmid. | the virc (formerly bak) complementation group of the nopaline-type ti plasmid ptic58 encodes two proteins, virc1 and virc2. according to the primary structure of the polypeptides predicted by the nucleotide sequence, virc1 is composed of 231 amino acids with a total molecular mass of 25.5 kilodaltons, and virc2 is composed of 202 amino acids with a molecular mass of 22.1 kilodaltons. the ptic58 virc1 and virc2 polypeptides are equal in length to virc1 and virc2 of the octopine-type plasmid ptia6 ... | 1987 | 3584058 |
| a locus encoding host range is linked to the common nodulation genes of bradyrhizobium japonicum. | by using cloned rhizobium meliloti, rhizobium leguminosarum, and rhizobium sp. strain mpik3030 nodulation (nod) genes as hybridization probes, homologous regions were detected in the slow-growing soybean symbiont bradyrhizobium japonicum usda 110. these regions were found to cluster within a 25-kilobase (kb) region. specific nod probes from r. meliloti were used to identify noda-, nodb-, nodc-, and nodd-like sequences clustered on two adjacent hindiii restriction fragments of 3.9 and 5.6 kb. a 7 ... | 1987 | 3584066 |
| nitrogen-fixing nodules induced by agrobacterium tumefaciens harboring rhizobium phaseoli plasmids. | rhizobium phaseoli cfn299 forms nitrogen-fixing nodules in phaseolus vulgaris (bean) and in leucaena esculenta. it has three plasmids of 185, 225, and 410 kilobases. the 410-kilobase plasmid contains the nitrogenase structural genes. we have transferred these plasmids to the plasmid-free strain agrobacterium tumefaciens gmi9023. transconjugants containing different combinations of the r. phaseoli plasmids were obtained, and they were exhaustively purified before nodulation was assayed. only tran ... | 1987 | 3584072 |
| agrobacterium tumefaciens ptar para promoter region involved in autoregulation, incompatibility and plasmid partitioning. | the locus responsible for directing proper plasmid partitioning of agrobacterium tumefaciens ptar is contained within a 1259 base-pair region. insertions or deletions within this locus can result in the loss of the plasmid's ability to partition properly. one protein product (para), approximately 25,000 mr, is expressed from the par locus in escherichia coli and a. tumefaciens protein analysis systems in vitro. dna sequence analysis of the locus revealed a single 23,500 mr open reading frame, co ... | 1987 | 3586028 |
| characterization of the vira locus of agrobacterium tumefaciens: a transcriptional regulator and host range determinant. | the virulence (vir) region of agrobacterium tumefaciens mediates the transfer of a defined segment of plasmid dna (the t-dna) into the plant genome. the vir genes are specifically induced by molecules produced by wounded plant cells, and vira is required for this induction. we have determined the nucleotide sequence of vira loci from limited (ptiag162) and wide (ptia6) host range tumor-inducing (ti) plasmids, each of which encodes a single protein of 92,000 daltons. using antibody directed again ... | 1987 | 3595559 |
| activation of agrobacterium tumefaciens vir gene expression generates multiple single-stranded t-strand molecules from the ptia6 t-region: requirement for 5' vird gene products. | agrobacterium tumefaciens transfers its ti-plasmid t-dna to plant cells. this process is initiated by plant-induced activation of the ti-plasmid virulence loci, resulting in the generation of single stranded (ss) cleavages of the ti-plasmid t-dna border sequences (border nicks) and ss linear unipolar t-dna molecules (t-strands). a single t-strand is produced from the two-border t-region of the pgv3850 nopaline plasmid. in this paper the induced molecular events for the complex t-region of the pt ... | 1987 | 3595560 |
| expression of rhizobium meliloti nod genes in rhizobium and agrobacterium backgrounds. | rhizobium meliloti nod genes are required for the infection of alfalfa. induction of the nodc gene depends on a chemical signal from alfalfa and on nodd gene expression. by using a nodc-lacz fusion, we have shown that the induction of the r. meliloti nodc gene and the expression of nodd occur at almost normal levels in other rhizobium backgrounds and in agrobacterium tumefaciens, but not in escherichia coli. xanthomonas campestris, or pseudomonas savastanoi. our results suggest that bacterial ge ... | 1987 | 3597319 |
| rhizobium meliloti swims by unidirectional, intermittent rotation of right-handed flagellar helices. | the 5 to 10 peritrichously inserted complex flagella of rhizobium meliloti mvii-1 were found to form right-handed flagellar bundles. bacteria swam at speeds up to 60 microns/s, their random three-dimensional walk consisting of straight runs and quick directional changes (turns) without the vigorous angular motion (tumbling) seen in swimming escherichia coli cells. observations of r. meliloti cells tethered by a single flagellar filament revealed that flagellar rotation was exclusively clockwise, ... | 1987 | 3597320 |
| identification of a new virulence locus in agrobacterium tumefaciens that affects polysaccharide composition and plant cell attachment. | we have identified a new virulence locus in agrobacterium tumefaciens. strains carrying tn5 inserts at this locus could not incite tumors on kalanchoe daigremontiana, nicotiana rustica, tobacco, or sunflower and had severely attenuated virulence on carrot disks. we termed the locus psca, because the mutants that defined the locus were initially isolated as having an altered polysaccharide composition; they were nonfluorescent on media containing leucophor or calcofluor, indicating a defect in th ... | 1987 | 3597321 |
| reexamination of the presence and linkage of 3-hydroxybutyryl substituents in the acidic capsular polysaccharide of rhizobium trifolii 0403. | we resolved previous conflicting results concerning the presence of 3-hydroxybutyryl substituents on the extracellular acidic polysaccharide from rhizobium trifolii 0403. these substituents were indeed present in the polysaccharide and in the oligosaccharide fragments obtained by hydrogen fluoride solvolysis of the extracellular and capsular polysaccharides of the bacteria grown on plates. the 3-hydroxybutyrate substituent could be removed from the polysaccharide by 10 mm sodium deuteroxide with ... | 1987 | 3597324 |
| flavonoids induce rhizobium leguminosarum to produce noddabc gene-related factors that cause thick, short roots and root hair responses on common vetch. | rhizobium leguminosarum produced a factor(s) that caused thick, short roots (tsr phenotype) as well as root hair induction (hai phenotype) and deformation (had phenotype) in vicia sativa plants upon incubation with root exudate or with one of the nod gene inducers naringenin or apigenin; this was a noddabc gene-dependent process. detection of the hai and had phenotypes was much more sensitive than that of the tsr phenotype. | 1987 | 3597326 |
| cloning and identification of lupin nodule specific cdna sequences. | yellow lupin nodule specific sequences were selected by screening of cdna library prepared from lupin nodule poly(a)+rna. from about 3,000 clones containing fragments of lupin dna 150-1,500 base pair long, 7% of clones carrying nodule specific sequences were identified. among them the most abundant sequence species, represented by 32% clones, encodes leghemoglobin. another abundant species designated pln13 is represented by 13% clones. the northern blot analysis of lupin mrna confirmed nodule sp ... | 1987 | 3604516 |
| characterization of agrobacterium tumefaciens strains isolated from grapevine tumors in china. | thirteen strains of agrobacterium tumefaciens isolated from grapevine tumors in northern china were surveyed. these strains varied in their host range properties, although all were tumorigenic on grapevines. twelve of these strains belonged to agrobacterium sp. biotype 3, and 11 strains resulted in the synthesis of the opine octopine in tumor tissue. interestingly, one strain resulted in accumulation of arginine, a previously unrecognized opine, in tumor tissue. although dna in most of these str ... | 1987 | 3606110 |
| promoter cassettes, antibiotic-resistance genes, and vectors for plant transformation. | we have constructed a set of plant transformation vectors, promoter cassettes, and chimeric antibiotic-resistance genes for the transformation and expression of foreign genes in plants sensitive to agrobacterium infection. the different vectors allow for either concurrent or consecutive selection for kanamycin and hygromycin resistance and have a number of unique restriction sites for the insertion of additional dna. the promoter cassettes utilize the camv 19s and camv 35s promoters and are cons ... | 1987 | 3609746 |
| structure of the bradyrhizobium japonicum gene hema encoding 5-aminolevulinic acid synthase. | the nucleotide (nt) sequence of the hema gene, which encodes 5-aminolevulinic acid synthase (alas) from the bacterium bradyrhizobium japonicum, is presented. this sequence predicts a protein of 408 amino acids (aa) with an mr of 44,599. this predicted amino acid sequence is highly homologous to that of the chicken embryonic liver alas, exhibiting a 48.8% identical amino acid sequence over the entire length of the bacterial protein. a single mrna start point was demonstrated by s1 protection anal ... | 1987 | 3609750 |
| structure of a polysaccharide containing galactose and galacturonic acid from rhizobium meliloti. characterization and partial purification of a 2-o-methyltransferase. | the teichuronic acid type polysaccharide found in rhizobium meliloti which is associated with sensitivity to phage 16b and is formed in the inner membranes from udp-galactose and udp-galacturonic acid (ugalde, r. a., coira, j. a., and brill, w. j. (1986) j. bacteriol. 168, 270-275) has been studied further. results of acid hydrolysis, periodate oxidation, and borohydride reduction show that this polysaccharide contains the repetitive unit -galacturonosyl(1-3)galactosyl(1-4-). a soluble enzyme wa ... | 1987 | 3611083 |
| homology studies demonstrate colinear organization of the transferred regions of plasmids pri 1855 and pri 8196 from agrobacterium rhizogenes. | agrobacterium rhizogenes, a pathogenic bacterium determining for hairy-root tumors in plants, acts by insertion of a fragment (t-dna) of its ri plasmid into the plant nuclear dna. two a. rhizogenes strains, pri 1855 and pri 8196, responsible for similar disease symptoms, differ when compared at the structural level. however, some morphogenetic loci previously identified by insertion mutagenesis in either one of the two t-dnas seem physiologically equivalent. the possibility that these morphogene ... | 1987 | 3615659 |
| [profiles of enzymatic activities of the genera agrobacterium, alcaligenes, alteromonas, flavobacterium and pseudomonas]. | profiles of enzymatic activities were studied using 19 chromogenic substrates for 22 species (211 strains) belonging to the genera agrobacterium, alcaligenes, alteromonas, flavobacterium and pseudomonas. the observed patterns of reactions may be useful as an aid in identification of these species and for epidemiological studies. | 1987 | 3620200 |
| a new vector derived from agrobacterium rhizogenes plasmids: a micro-ri plasmid and its use to construct a mini-ri plasmid. | a new binary vector system has been constructed, based on agropine-type root-inducing plasmid (pri) left transferred-region border sequences cloned in a plasmid containing the replication origin of another a. rhizogenes plasmid (para4a). this micro-pri has been used to introduce a chimeric kanamycin resistance gene into tobacco plants, vir functions being provided by either octopine or nopaline tumor-inducing plasmids deleted of their own transferred regions. in addition, we show that cloning of ... | 1987 | 3623102 |
| cytokinin production by agrobacterium and pseudomonas spp. | the production of cytokinins by plant-associated bacteria was examined by radioimmunoassay. strains producing trans-zeatin were identified in the genera agrobacterium and pseudomonas. agrobacterium tumefaciens strains containing nopaline tumor-inducing plasmids, a. tumefaciens lippia isolates, and agrobacterium rhizogenes strains produced trans-zeatin in culture at 0.5 to 44 micrograms/liter. pseudomonas solanacearum and pseudomonas syringae pv. savastanoi produced trans-zeatin at levels of up t ... | 1987 | 3624204 |
| involvement of both cellulose fibrils and a ca2+-dependent adhesin in the attachment of rhizobium leguminosarum to pea root hair tips. | we have previously described an assay for the attachment of rhizobium bacteria to pea root hair tips (cap formation) which was used as a model to study the attachment step in the nodulation process. under all conditions tested, a positive correlation was observed between the percentage of fibrillated cells and the ability of these bacteria to form caps and to adhere to glass, suggesting that fibrils play a role in the attachment of rhizobium leguminosarum to pea root hair tips and to glass (g. s ... | 1987 | 3624205 |
| a. tumefaciens pti a6 and c58 vir c and d promoter alignment. | 1987 | 3628008 | |
| three-dimensional structure of the complex flagellar filament of rhizobium lupini and its relation to the structure of the plain filament. | electron micrographs of negatively stained preparations were used to obtain a three-dimensional reconstruction of the complex flagellar filament of rhizobium lupini h13-3. the complex filament has an organization similar to that of the more common plain filament, but the subunits are perturbed in a pairwise fashion to generate a very distinctive set of three continuous ridges of density along the outer surface of the filament. in the three-dimensional map, the design of the complex filament is s ... | 1987 | 3656426 |
| molecular characterization of the vird operon from agrobacterium tumefaciens. | the agrobacterium tumefaciens ti plasmid virulence (vir) region contains at least six transcriptional units required for the efficient transfer of t-dna to the plant genome (vira, b, c, d, e, and g). we have reported that two proteins encoded by the 5'portion of the vird operon are required for a site-specific endonuclease activity that nicks the direct repeats which flank the t-dna. we have presented the nucleotide sequence for this portion of the operon. the nucleotide sequence of the remainde ... | 1987 | 3658701 |
| requirement of succinate dehydrogenase activity for symbiotic bacteroid differentiation of rhizobium meliloti in alfalfa nodules. | transmission electron microscopy was used to study the cellular morphologies of a wild-type rhizobium meliloti strain (l5-30), a nitrogen fixation-ineffective (fix-) succinate dehydrogenase mutant (sdh-) strain, and a fix+ sdh+ revertant strain within alfalfa nodules and after free-living growth in a minimal medium containing 27 mm mannitol plus 20 mm succinate. the results showed a requirement of succinate dehydrogenase activity for symbiotic differentiation and maintenance of r. meliloti bacte ... | 1987 | 3662521 |
| [denitrifying activity and generation time in 4 species of rhizobium]. | denitrifying capacity and doubling time were measured among 44 strains of rhizobium belonging to 4 species: b. japonicum, r. lupini, r. meliloti et r. leguminosarum. there was no correlation between doubling time and the rate of production of n2o in the presence of c2h2 in b. japonicum and r. lupini. in 38 other strains, only denitrifying capacity was measured. the percentage of strains showing denitrification capacity varied according to the species: 70% in b. japonicum, 90% in r. lupini, 37% i ... | 1987 | 3663388 |
| characterization of the lipopolysaccharide from a rhizobium phaseoli mutant that is defective in infection thread development. | the lipopolysaccharide (lps) from a rhizobium phaseoli mutant, ce109, was isolated and compared with that of its wild-type parent, ce3. a previous report has shown that the mutant is defective in infection thread development, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis shows that it has an altered lps (k. d. noel, k. a. vandenbosch, and b. kulpaca, j. bacteriol. 168:1392-1462, 1986). mild acid hydrolysis of the ce3 lps released a polysaccharide and an oligosaccharide, ps1 and p ... | 1987 | 3667520 |
| dual control of agrobacterium tumefaciens ti plasmid virulence genes. | the virulence genes of nopaline (ptic58) and octopine (ptia6nc) ti plasmids are similarly affected by the agrobacterium tumefaciens ros mutation. of six vir region complementation groups (vira, virb, virg, virc, vird, and vire) examined by using fusions to reporter genes, the promoters of only two (virc and vird) responded to the ros mutation. for each promoter that was affected by ros, the level of expression of its associated genes was substantially elevated in the mutant. this increase was no ... | 1987 | 3667525 |
| chemotaxis to plant phenolic inducers of virulence genes is constitutively expressed in the absence of the ti plasmid in agrobacterium tumefaciens. | the virulence (vir) genes are required in the early stages of plant tumor formation and are located together on the tumor-inducing (ti) plasmid in agrobacterium tumefaciens. five of the vir genes are expressed inducibly in response to the following monocyclic phenolic compounds: acetosyringone, catechol, gallate, beta-resorcylate, protocatechuate, p-hydroxybenzoate, and vanillin. of these compounds, only the latter six, excluding vanillin [corrected] served as chemoattractants and only the latt ... | 1987 | 3667536 |
| deduced products of c4-dicarboxylate transport regulatory genes of rhizobium leguminosarum are homologous to nitrogen regulatory gene products. | we have sequenced two genes dctb and dctd required for the activation of the c4-dicarboxylate transport structural gene dcta in free-living rhizobium leguminosarum. the hydropathic profile of the dctb gene product (dctb) suggested that its n-terminal region may be located in the periplasm and its c-terminal region in the cytoplasm. the c-terminal region of dctb was strongly conserved with similar regions of the products of several regulatory genes that may act as environmental sensors, including ... | 1987 | 3671068 |
| plant expression signals of the agrobacterium t-cyt gene. | within the 5' and 3' non-coding regions of the t-cyt gene from the octopine t-dna of agrobacterium tumefaciens sequences required for expression of this gene in plant cells were identified by deletion mutagenesis. the results show that 184 bp of the 5' non-coding region and 270 bp of the 3' non-coding region are sufficient for wild-type expression. within the 5' non-coding region two essential expression signals were identified: (1.) an activator element located between -185 and -129 with respec ... | 1987 | 3671083 |
| effects of mutations in the tata box region of the agrobacterium t-cyt gene on its transcription in plant tissues. | we have generated mutations in the promoter region of the octopine type cytokinin gene of agrobacterium tumefaciens, and studied their effects on mrna formation in different plant species. the promoter region of this gene contains several putative tata boxes. phenotypic expression and northern blot hybridization showed that tata boxes are essential for expression, but that one tata box leads to wild-type transcript levels. analysis of the 5' ends of t-cyt transcripts by primer extension using rn ... | 1987 | 3671084 |
| septicemia with agrobacterium species from a permanent vena cephalica catheter. a case report. | a case of agrobacterium septicemia is reported in a 47-year-old woman with disseminated adenomcarcinoma mammae and a permanent vena cephalica catheter. | 1987 | 3673587 |
| agrobacterium tumefaciens virulence locus psca is related to the rhizobium meliloti exoc locus. | agrobacterium tumefaciens and rhizobium meliloti carry related genetic loci which have important roles in virulence and symbiosis. previously, it was shown that two virulence loci of a. tumefaciens, chva and chvb, are related to two r. meliloti symbiosis loci, ndva and ndvb, respectively (t. dylan, l. ielpi, s. stanfield, l. kashyap, c. douglas, m. yanofsky, e. nester, d. r. helinski, and g. ditta, proc. natl. acad. sci. usa 83:4403-4407, 1986). here we show that these two phytobacteria possess ... | 1987 | 3680180 |
| overdrive is a t-region transfer enhancer which stimulates t-strand production in agrobacterium tumefaciens. | introduction of a left or right synthetic border repeat together with the overdrive sequence in an octopine ti-plasmid deletion mutant, lacking the right border, resulted in the complete restoration of the oncogenicity of the mutant strain. however introduction of a border repeat without the overdrive, only restored oncogenicity partially. the overdrive sequence turned out to be able to stimulate the synthetic border mediated t-region transfer, independent of its orientation and position relativ ... | 1987 | 3684577 |
| induction of the noda promoter of rhizobium leguminosarum sym plasmid prl1ji by plant flavanones and flavones. | an expression vector containing the rhizobium leguminosarum noda promoter cloned in front of the escherichia coli lacz gene was used to characterize the properties of the r. leguminosarum noda gene-inducing compound(s) present in sterile root exudate of the host plant vicia sativa l. subsp. nigra (l.). the major inducing compound was flavonoid in nature, most likely a flavanone. the commercially available flavonoids naringenin (5,7,4'-trihydroxyflavanone), eriodictyol (5,7,3'4'-tetrahydroxyflava ... | 1987 | 3539915 |
| nucleotide sequence of the gene encoding the nitrogenase iron protein of thiobacillus ferrooxidans. | the dna sequence was determined for the cloned thiobacillus ferrooxidans nifh and part of the nifd genes. a putative t. ferrooxidans nifh promoter was identified whose sequences showed perfect consensus with those of the klebsiella pneumoniae nif promoter. two putative consensus upstream activator sequences were also identified. the amino acid sequence was deduced from the dna sequence. in a comparison of nifh dna sequences from t. ferrooxidans and eight other nitrogen-fixing microbes, a rhizobi ... | 1987 | 3539923 |
| sequence of psi, a gene on the symbiotic plasmid of rhizobium phaseoli which inhibits exopolysaccharide synthesis and nodulation and demonstration that its transcription is inhibited by psr, another gene on the symbiotic plasmid. | a gene termed psi (polysaccharide inhibition), located close to the nodulation genes of the rhizobium phaseoli symbiotic plasmid prp2ji inhibited exopolysaccharide synthesis (eps) and nodulation ability (nod) in rhizobium when it was cloned in a multicopy plasmid. the sequence of psi showed that it specified a polypeptide of mol. wt. 10,000 that may be associated with the membrane of rhizobium. a second gene, psr (polysaccharide restoration), was located on prp2ji. when cloned in multicopy plasm ... | 1987 | 3474492 |
| identification of two classes of rhizobium phaseoli genes required for melanin synthesis, one of which is required for nitrogen fixation and activates the transcription of the other. | the symbiotic plasmid prp2ji of rhizobium phaseoli strain 8002 was shown to contain two separate regions of dna which are required and sufficient for the synthesis of the pigment melanin. one of these regions containing the class ii mel gene(s) was located to other genes involved in nodulation and in nitrogen fixation. mutations in this region abolished both the ability to synthesize melanin and to fix nitrogen in phaseolus bean root nodules. mutations in the other, unlinked region, containing c ... | 1987 | 3474493 |
| high meiotic stability of a foreign gene introduced into tobacco by agrobacterium-mediated transformation. | two lines of transgenic nicotiana tabacum transformed to kanamycin resistance by means of a binary agrobacterium vector containing a nos-npt gene were investigated over three generations. southern hybridization and crossing analyses revealed that a single copy of t-dna had integrated in each line and that the kanamycin resistance was regularly transmitted to the progeny as a monogenic dominant trait. homozygous transgenic plants were fully fertile, morphologically normal and did not significantl ... | 1987 | 3474494 |
| west german release of altered bacteria causes furore. | 1987 | 3475577 | |
| rhizobium meliloti has three functional copies of the nodd symbiotic regulatory gene. | we have identified two rhizobium meliloti genes (nodd2 and nodd3) that are highly homologous and closely linked to the regulatory gene nodd (nodd1). r. meliloti strains containing mutations in the three nodd genes in all possible combinations were constructed and their nodulation phenotypes were assayed on medicago sativa (alfalfa) and melilotus alba (sweet clover). a triple nodd1-nodd2-nodd3 mutant exhibited a nod- phenotype on alfalfa and sweet clover, indicating that nodd is an essential nodu ... | 1987 | 3479806 |
| mobilization of t-dna from agrobacterium to plant cells involves a protein that binds single-stranded dna. | crude protein extracts of induced and uninduced octopine wild-type strain of agrobacterium tumefaciens, as well as several mutants of the virulence loci vira, -b, -g, -c, -d, and -e, were probed with single- and double-stranded synthetic oligodeoxynucleotides of different sequence and length in an electrophoretic retardation assay. four complexes involving sequence-nonspecific, single-stranded-dna-binding proteins were recognized. one inducible complex is determined by the vire locus, two ti-pla ... | 1987 | 3480525 |
| the nucleotide sequence of the sigma factor gene ntra (rpon) of azotobacter vinelandii: analysis of conserved sequences in ntra proteins. | the nucleotide sequence of the azotobacter vinelandii ntra gene has been determined. it encodes a 56916 dalton acidic polypeptide (avntra) with substantial homology to ntra from klebsiella pneumoniae (kpntra) and rhizobium meliloti (rmntra). ntra has been shown to act as a novel rna polymerase sigma factor but the predicted sequence of avntra substantiates our previous analysis of kpntra in showing no substantial homology to other known sigma factors. alignment of the predicted amino acid sequen ... | 1987 | 3481423 |
| site-directed tn5 and transplacement mutagenesis: methods to identify symbiotic nitrogen fixation genes in slow-growing rhizobium. | 1987 | 2828853 | |
| characterization of agrobacterium tumefaciens virulence proteins induced by the plant factor acetosyringone. | the ti plasmid virulence (vir) loci encode functions essential for the transfer of the t-dna element from agrobacterium tumefaciens to plant cells. the expression of these loci is specifically signaled by plant phenolics such as acetosyringone. here, we characterize the protein products that are induced in agrobacterium grown in the presence of acetosyringone. more than 10 to 15 proteins are induced in strains harboring different ti plasmids. two general classes of acetosyringone-induced protein ... | 1987 | 3430596 |
| design and construction of a versatile system for the expression of foreign genes in plants. | we have built a series of vectors to allow the constitutive or light-regulated expression of foreign genes in plants. these vectors carry expression cassettes consisting of either the cauliflower mosaic virus 35s promoter or the pea rbcs-e9 promoter, a multiple cloning site derived from m13um20, and the rbcs-e9 polyadenylation site. these cassettes have been incorporated into pbr322-based or rk2-based replicons to facilitate direct dna uptake or agrobacterium tumefaciens-mediated gene transfer. ... | 1987 | 3443303 |
| deproteinized leaf juice as a medium for growth of rhizobium. | 1987 | 3446598 | |
| a study of predominant aerobic microflora of black bears (ursus americanus) and grizzly bears (ursus arctos) in northwestern alberta. | swab specimens were obtained from nasal, rectal, and preputial or vaginal areas of 37 grizzly and 17 black bears, captured during may to june of 1981 to 1983, to determine the types and frequency of predominant aerobic microflora. bacterial genera most frequently isolated from bears were escherichia, citrobacter, hafnia, proteus, staphylococcus, and streptococcus species, comprising about 65% of the isolates. erwinia, xanthomonas, agrobacterium, rhizobium, and gluconobacter/acetobacter were also ... | 1987 | 3447691 |
| nucleotide sequence of the virg locus of the agrobacterium tumefaciens plasmid ptic58. | the nucleotide sequence of the virg locus of the nopaline type plasmid ptic58 of agrobacterium tumefaciens has been determined. it contains an open reading frame (orf) of 759 nucleotides and has 77% homology to the virg sequences of octopine type plasmids. differences between the sequences of the two types of ti plasmids in the region of virg are located predominantly outside the orf. the amino acid sequences inferred from the two virg genes show 80% homology to each other and each shows the sam ... | 1987 | 3448462 |
| reiterated dna sequences in rhizobium and agrobacterium spp. | repeated dna sequences are a general characteristic of eucaryotic genomes. although several examples of dna reiteration have been found in procaryotic organisms, only in the case of the archaebacteria halobacterium halobium and halobacterium volcanii [c. sapienza and w. f. doolittle, nature (london) 295:384-389, 1982], has dna reiteration been reported as a common genomic feature. the genomes of two rhizobium phaseoli strains, one rhizobium meliloti strain, and one agrobacterium tumefaciens stra ... | 1987 | 3450286 |
| interaction between gram varieties and rhizobium isolates in relation to nodulation, plant growth and grain yield. | 1987 | 3450684 | |
| cyclic glucans produced by agrobacterium tumefaciens are substituted with sn-1-phosphoglycerol residues. | in a previous study (miller, k.j., kennedy, e.p. and reinhold, v.n. (1986) science 231, 48-51) it was reported that the biosynthesis of periplasmic cyclic beta-1,2-glucans by agrobacterium tumefaciens is strictly osmoregulated in a pattern closely similar to that found for the membrane-derived oligosaccharides of escherichia coli (kennedy, e.p. (1982) proc. natl. acad. sci. usa 79, 1092-1095). in addition to the well-characterized neutral cyclic glucan, the periplasmic glucans were found to cont ... | 1987 | 3297148 |
| complementation of a threonine dehydratase-deficient nicotiana plumbaginifolia mutant after agrobacterium tumefaciens-mediated transfer of the saccharomyces cerevisiae ilv1 gene. | the saccharomyces cerevisiae ilv1 gene, encoding threonine dehydratase (ec 4.2.1.16) was fused to the transferred dna nopaline synthase promoter and the 3' noncoding region of the octopine synthase gene. it was introduced, by agrobacterium tumefaciens-mediated gene transfer, into an isoleucine-requiring nicotiana plumbaginifolia auxotroph deficient in threonine dehydratase. functional complementation by the ilv1 gene product was demonstrated by the selection of several transformed lines on a med ... | 1987 | 3302681 |
| new questions in strobel case. | 1987 | 3306915 | |
| a set of positively regulated flagellar gene promoters in caulobacter crescentus with sequence homology to the nif gene promoters of klebsiella pneumoniae. | the study reported here describes nuclease s1 mapping of the in-vivo transcription start sites of transcription units i and iii of the hook gene cluster of caulobacter crescentus. we show that transcription units i and ii of this flagellar (fla) gene cluster, which have divergent promoters with transcription start sites separated by 218 nucleotides, are under positive transcriptional control by genes in transcription unit iii. the promoters of transcription units i, ii, and iii were compared wit ... | 1987 | 3309346 |
| the symbiotic nitrogen fixation regulatory operon (fixrnifa) of bradyrhizobium japonicum is expressed aerobically and is subject to a novel, nifa-independent type of activation. | the bradyrhizobium japonicum n2 fixation regulatory gene, nifa, was sequenced and its transcription start site determined. between the start of transcription and the nifa gene an open reading frame of 278 codons was found and named fixr. a deletion in fixr which allowed transcription into nifa resulted in a 50% reduced fix activity. the fixrnifa operon was expressed in soybean root nodules, in cultures grown anaerobically with nitrate as terminal electron acceptor, in microaerobic cultures, and ... | 1987 | 3313281 |
| lupin leghemoglobins during root nodule development. | two yellow lupin leghemoglobins, lb i and lb ii, were purified to homogeneity using the hplc technique for final separation. lb i and lb ii were identified by the n-terminal sequences and their reaction with antibodies against electrophoretically pure leghemoglobin. the third lb species was detected by the combined method of isoelectrofocusing and page of lb i. it seems that lb iii represents a posttranslational modification of lb i. developmental changes in lb multiple forms were examined using ... | 1987 | 3314293 |
| rhizobium meliloti nifn (fixf) gene is part of an operon regulated by a nifa-dependent promoter and codes for a polypeptide homologous to the nifk gene product. | an essential gene for symbiotic nitrogen fixation (fixf) is located near the common nodulation region of rhizobium meliloti. a dna fragment carrying fixf was characterized by hybridization with klebsiella pneumoniae nif dna and by nucleotide sequence analysis. the fixf gene was found to be related to k. pneumoniae nifn and was therefore renamed as the r. meliloti nifn gene. upstream of the nifn coding region a second open reading frame was identified coding for a putative polypeptide of 110 amin ... | 1987 | 3316182 |
| physiology, biochemistry, and genetics of the uptake hydrogenase in rhizobia. | 1987 | 3318673 | |
| evidence that dna involved in the expression of nodulation (nod) genes in rhizobium binds to the product of the regulatory gene nodd. | in rhizobium leguminosarum biovar viciae, the regulatory nodulation nodd gene has at least two functions. it constitutively represses its own transcription and in the presence of inducer flavonoid molecules, it activates the expression of two other nod gene transcriptional units, nodabcij and nodfe. upstream of noda and nodf is a conserved sequence, the nod box, which has been implicated in nodd-mediated transcriptional activation of these genes. dna fragments spanning the nod boxes that precede ... | 1987 | 3320955 |
| incompatibility between a rhizobium sym plasmid and a ri plasmid of agrobacterium. | the symbiotic plasmid of rhizobium trifolii g1008 was mobilized to other rhizobium strains and to agrobacterium using tn5-mob, a transposon that confers on a host replicon the ability to be mobilized in trans by rp4. incompatibility was observed between psymg1008 and the hairy-root-inducing plasmid pri1855. agarose gel electrophoresis revealed that pri1855 was eliminated as an autonomous element in the presence of psymg1008 and its absence was correlated with loss of the ability to induce hairy ... | 1987 | 3324125 |
| foreign gene expression in plant cells. | 1987 | 3326039 | |
| [introduction and expression of foreign genes into plant cells using a ti plasmid vector]. | 1987 | 3334467 | |
| bacterial carbon-phosphorus lyase: products, rates, and regulation of phosphonic and phosphinic acid metabolism. | carbon-phosphorus bond cleavage activity, found in bacteria that utilize alkyl- and phenylphosphonic acids, has not yet been obtained in a cell-free system. given this constraint, a systematic examination of in vivo c-p lyase activity has been conducted to develop insight into the c-p cleavage reaction. six bacterial strains were obtained by enrichment culture, identified, and characterized with respect to their phosphonic acid substrate specificity. one isolate, agrobacterium radiobacter, was s ... | 1987 | 3804975 |