Publications

gene transfer in cereals.	until recently, gene transfer in plants was achieved only by sexual hybridization. now, in addition, plant genetic manipulation, with the use of both recombinant dna and protoplast fusion technology, is being applied to an increasing range of plants. the soil bacterium agrobacterium tumefaciens, with its associated plasmid, is used as a vector for introducing dna into the genomes of dicotyledonous plants, but it has not proved suitable for cereals. instead, the direct uptake of plasmid dna into ...	1987	17770329
expression of alfalfa mosaic virus and tobacco rattle virus coat protein genes in transgenic tobacco plants.	using the agrobacterium tumefaciens binary vector system, a chimeric gene consisting of the cauliflower mosaic virus 35 s promoter, alfalfa mosaic virus (aimv) coat protein (cp) cistron, and the nopaline synthase polyadenylation signal was integrated into the genome of nicotiana tabacum cv. samsun nn. in 70% of the transgenic tobacco plants the chimeric mrna and its translation product could be detected. cp accumulated to levels up to 0.05% of the soluble leaf protein. the accumulation was indep ...	1987	18644569
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
transfer of drosophila melanogaster transponsable genetic element mdg-4 into plant cells.	the copia-like element mdg-4, as a component of the drosophila genomic fragment dm111, was cloned into the vector pib16. the chimaeric plasmid pib16 [dm111] was used to transform tobacco cells as a cointegrate with ptic58 (agrobacterium tumefaciens), ptic58::pib16 [dm111]. the growth properties of primary crown-gall tumours were followed, and the dna of one nicotiana tabacum transformant was further analysed. the dna/dna molecular hybridization of digests of genomic dna with 32p-labelled pdm111 ...	1987	3032699
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
biosynthesis and degradation of nodule-specific rhizobium loti compounds in lotus nodules.	two nodule-specific rhizobium loti compounds were identified in lotus tenuis and lotus pedunculatus nodules induced by strain nzp2037. one, a silver nitrate-positive cation called rhizolotine, has been characterized as the riboside of a novel alpha-hydroxyimino acid containing a 1,4,5,6-tetrahydropyrimidine ring (g. j. shaw, r. d. wilson, g. a. lane, l. d. kennedy, d. b. scott, and g. j. gainsford, j. chem. soc. chem. commun., p. 180-181, 1986), and the other, yellow-1, stains yellow with ninhyd ...	1987	3025173
characterization of nonattaching mutants of agrobacterium tumefaciens.	the first step in tumor formation by agrobacterium tumefaciens is the site-specific binding of the bacteria to plant host cells. transposon mutants of the bacteria which fail to attach to carrot suspension culture cells were isolated. these mutants showed no significant attachment to carrot cells with either microscopic or viable cell count assays of bacterial binding. the nonattaching mutants were all avirulent. when revertants of the mutants were obtained by enriching for bacteria which do bin ...	1987	3025176
double-stranded cleavage of t-dna and generation of single-stranded t-dna molecules in escherichia coli by a vird-encoded border-specific endonuclease from agrobacterium tumefaciens.	the vird locus of agrobacterium tumefaciens ti plasmid ptia6 was sequenced. computer analysis of the sequence indicated five possible open reading frames (orfs) within this locus. two additional orfs were identified distal to this locus. however, only two polypeptides of apparent molecular masses 16 and 56 kilodaltons, the products of orfs 1 and 2, were detected in escherichia coli, both in vivo and in an in vitro coupled transcription-translation system. the vird locus was cloned in expression ...	1987	2822660
regulation of the vir genes of agrobacterium tumefaciens plasmid ptic58.	the virulence (vir) region of ptic58 was screened for promoter activities by using gene fusions to a promoterless lux operon in the broad-host-range vector pucd615. active vir fragments contained the strongly acetosyringone-inducible promoters of virb, virc, vird, and vire and the weakly inducible promoters of vira and virg. identical induction patterns were obtained with freshly sliced carrot disks, suggesting that an inducer is released after plant tissue is wounded. optimal conditions for vir ...	1987	2822665
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
similarities between nucleotide sequences of insertion elements of agrobacterium tumefaciens and pseudomonas savastanoi in relation to agrobacterium tumefaciens tc-dna.		1987	2827126
genetic analysis of the gentamicin resistance region of pph1ji and incorporation into a wide host range cloning vehicle.	a region of the incp plasmid pph1ji encoding resistance to gentamicin, spectinomycin, and streptomycin was characterized by subcloning, deletion, and insertion mutagenesis. approximate locations of these resistance determinants were established. a 1.6-kb hindiii-sphi segment of this region expresses gentamicin resistance (gmr) in escherichia coli when inserted into various plasmid vectors; this dna segment encodes a polypeptide of 17.5 kda. incorporation of this fragment into an incp cloning veh ...	1987	2827208
analysis of cell division gene ftsz (sulb) from gram-negative and gram-positive bacteria.	the ftsz (sulb) gene of escherichia coli codes for a 40,000-dalton protein that carries out a key step in the cell division pathway. the presence of an ftsz gene protein in other bacterial species was examined by a combination of southern blot and western blot analyses. southern blot analysis of genomic restriction digests revealed that many bacteria, including species from six members of the family enterobacteriaceae and from pseudomonas aeruginosa and agrobacterium tumefaciens, contained seque ...	1987	2432055
genetic analysis of agrocin 84 production and immunity in agrobacterium spp.	mutations affecting agrocin production on the 48-kilobase (kb) plasmid, pagk84, can be complemented in trans with cloned portions of the plasmid. five complementation groups ranging in minimum size from 1.2 to 5.6 kb were identified within a 14-kb segment. plasmid pagk84-encoded immunity to agrocin 84 was located to two separate regions of the plasmid. either region alone was sufficient to protect sensitive strains, and both loci mapped to the agrocin 84 biosynthesis region. one region is locate ...	1987	2442139
genes responsible for the supervirulence phenotype of agrobacterium tumefaciens a281.	agrobacterium tumefaciens a281 induces large, rapidly appearing tumors on a variety of plants and has a wider host range than other strains of a. tumefaciens. by using tn3hoho1 transposon mutagenesis and complementation analysis, a 2.5-kilobase dna fragment which is responsible for the supervirulence phenotype was identified in the virulence (vir) region of the ti plasmid. this fragment contains the virg locus, as well as the 3' end of the virb operon. a clone of this fragment conferred the supe ...	1987	2443480
expression of mouse dihydrofolate reductase gene confers methotrexate resistance in transgenic petunia plants.	transgenic petunia plants containing an altered (leu22----arg22) mouse dihydrofolate reductase gene fused to the cauliflower mosiac virus 35s (camv 35s) promoter and nopaline synthase (nos) polyadenylation site were obtained by transforming petunia leaf disks with an agrobacterium tumefaciens strain carrying the chimeric gene. transformants were directly selected for and rooted on medium containing 1 microm methotrexate (mtx). the chimeric gene was present in the regenerated plants at one to thr ...	1987	3468634
the promoter proximal region in the vird locus of agrobacterium tumefaciens is necessary for the plant-inducible circularization of t-dna.	the formation of crown gall tumours involves the transfer of the t-dna region of the ti plasmid from agrobacterium to plant cells and its subsequent integration into plant chromosomes. when agrobacteria are incubated with plant protoplasts or exudates of plants, the t-dna region is circularized by recombination or cleavage and rejoining between the 25 bp terminal repeats; the formation of circular t-dnas is thought to be one step in t-dna transfer (koukolikova-nicola et al. 1985; machida et al. ...	1987	3472033
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
in vitro activity of a-56268 (te-031), a new macrolide antibiotic, compared with that of erythromycin and other antimicrobial agents.	a-56268 is a new macrolide antibiotic that resembles erythromycin in its spectrum of activity. a-56268 and erythromycin had identical activities against streptococcus pyogenes, group b, c, and g streptococci, and viridans group streptococci. erythromycin and a-56268 had similar activities against staphylococcus aureus, coagulase-negative staphylococci, and group d enterococci. like erythromycin, a-56268 was ineffective in inhibiting oxacillin-resistant s. aureus, oxacillin-resistant, coagulase-n ...	1987	2955742
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
a rhizobium meliloti mutant that forms ineffective pseudonodules in alfalfa produces exopolysaccharide but fails to form beta-(1----2) glucan.	a mutant of rhizobium meliloti that elicited the formation of inactive nodules in alfalfa was found not to form beta-(1----2) glucan in vivo or in vitro. it was nonmotile because it lacks flagella. the 235-kilodalton protein which acts as an intermediate in beta-(1----2) glucan synthesis was undetectable in the mutant. these properties of the mutant are common to those of chvb mutants of agrobacterium tumefaciens. exopolysaccharide formation by the r. meliloti mutant was about double that by the ...	1987	3804979
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
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
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
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
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
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
detection of opines by colorimetric assay.	a colorimetric procedure for confirming the presence of arginine-derived opines (nopaline and octopine) in plant tissue extracts is described. those materials are widely used as markers of plant cell transformation and tumorigenesis mediated by the tumor-inducing plasmids of agrobacterium tumefaciens. nopaline and octopine are generally detected, following resolution by paper electrophoresis, by observation of the uv-fluorescent products formed upon reaction with phenanthrenequinone. we found th ...	1987	3578760
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
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
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
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
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
pseudomonas stutzeri septicemia.		1987	3611326
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
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
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
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
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
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
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
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
absence in monocotyledonous plants of the diffusible plant factors inducing t-dna circularization and vir gene expression in agrobacterium.	t-dna circularization is one of the molecular events specifically induced in agrobacterial cells upon their infection of dicotyledonous plant cells. we developed a seedling co-cultivation procedure to determine whether or not monocotyledonous plants have the ability to induce t-dna circularization and vir gene expression. co-cultivation of agrobacterium tumefaciens with seedlings of dicotyledonous plants showed that the circularization event takes place efficiently. the exudates and extracts of ...	1987	17191337
the ntrc gene of agrobacterium tumefaciens c58 controls glutamine synthetase (gsii) activity, growth on nitrate and chromosomal but not ti-encoded arginine catabolism pathways.	the ntrc locus of agrobacterium tumefaciens c58 has been cloned using the azorhizobium sesbaniae ors571 ntrc gene as a dna hybridization probe. transposon tn5 mutagenesis of the cloned ntrc locus was carried out and one tn5 insertion within the region of highest dna homology with a. sesbaniae ors571 ntrc was used for gene replacement of the wild-type c58 ntrc gene. the a. tumefaciens ntrc::tn5 mutant was found to be unable to grow on nitrate as sole nitrogen (n) source, to lack glutamine synthet ...	1987	17193704
a plasmid sequence from rhizobium leguminosarum 300 contains homology to sequences near the octopine tl-dna right border.	the dna sequence from a rhizobium leguminosarum 300 (rl300) plasmid that contains homology to the tc-dna of agrobacterium tumefaciens is described. the rl300 sequence has 78% homology to a 359 bp sequence in the tc-dna of pti15955. the rl300 homology starts approximately 100 bp from the 24 bp border sequence of the tl-dna and ends approximately 3 bp from an is66 homolog in the tc-dna. an unusual feature of the rl300 homology is the presence of 81 bp direct repeats with tc-dna homology, separated ...	1987	17193713
inhibitory effects of a pectin-enriched tomato cell wall fraction on agrobacterium tumefaciens binding and tumor formation.	a pectin-enriched soluble cell wall fraction (cwf) prepared from suspension cultured tomato cells inhibits binding of agrobacterium tumefaciens to these cells. it was hypothesized that the cwf contains the plant surface binding site for a. tumefaciens (nt neff, an binns 1985 plant physiol 77: 35-42). experiments described here demonstrate that tomato cwf inhibited tumor formation on potato slices and agrobacterium binding to intact tomato cells in a dose-dependent fashion. boiling the fraction r ...	1987	16665282
virulence of agrobacterium tumefaciens strain a281 on legumes.	this study addresses the basis of host range on legumes of agrobacterium tumefaciens strain a281, an l,l-succinamopine strain. we tested virulence of t-dna and vir region constructs from this tumor-inducing (ti) plasmid with complementary ti plasmid regions from heterologous nopaline and octopine strains.	1987	16665283
involvement of carrot cell surface proteins in attachment of agrobacterium tumefaciens.	the initial step in tumor formation by agrobacterium tumefaciens is the site-specific attachment of the bacteria to plant cells. a similar attachment to plant tissue culture cells has been observed. binding to carrot suspension culture cells was not dependent on the presence of divalent cations and was not inhibited by the addition of mannose, alpha-methyl mannoside, galactose, arabinose, glucosamine, 2-deoxyglucose, or 0.25 molar nacl to the culture medium. the ability of the carrot cells to bi ...	1987	16665289
expression from heterologous promoters in electroporated carrot protoplasts.	plasmids were constructed that contained promoters of ;plant' genes fused to the bacterial gene for chloramphenicol acetyl transferase. the promoters were isolated from a developmentally regulated zea mays seed storage protein gene and from the mannopine synthase gene of the octopine type ti plasmid of agrobacterium tumefaciens which is constitutively expressed in crown gall tumors. these plasmids were introduced into carrot protoplasts made permeable by electroporation. expression of chloramphe ...	1987	16665331
bacillus thuringiensis section sign-endotoxin expressed in transgenic nicotiana tabacum provides resistance to lepidopteran insects.	the crystal proteins, or section sign-endotoxins, of bacillus thuringiensis are specifically lethal to lepidopteran insects. we utilized a truncated and modified portion of a cloned crystal protein gene to construct a chimeric gene capable of expression in plant cells. using an agrobacterium tumefaciens binary vector system, we then transferred the chimeric toxin gene into tobacco (nicotiana tabacum cv havana 425) cells and regenerated recombinant plants. one to several copies per cell of the to ...	1987	16665812
virulence genes a, g, and d mediate the double-stranded border cleavage of t-dna from the agrobacterium ti plasmid.	agrobacterium tumefaciens transfers the t-dna portion of its ti plasmid to the nuclear genome of plant cells. upon cocultivation of a. tumefaciens strain a348 with regenerating tobacco leaf protoplasts, restriction endonuclease fragments of the t-dna were generated that are consistent with double-stranded cleavage of the t-dna at the border sequences. the t-dna border cleavage was also induced by acetosyringone, a compound that induces many of the virulence genes. t-dna cleavage did not occur in ...	1987	16593820
t-dna organization in tumor cultures and transgenic plants of the monocotyledon asparagus officinalis.	asparagus officinalis was the first monocotyledonous plant from which hormone-independent and opine-producing crown gall tissue could be isolated. we confirm by dna hybridization that tumor lines obtained after infection of this plant by agrobacterium strains harboring wild-type nopaline and octopine tumor-inducing (ti) plasmids are stably transformed and contain transferred dna (t-dna) segments identical to the t-dna found in dicotyledonous plants. we have also infected asparagus with a nononco ...	1987	16593862
integration of agrobacterium tumefaciens transfer dna (t-dna) involves rearrangements of target plant dna sequences.	the transfer dna (t-dna) mobilized into plant cells by agrobacterium tumefaciens seems to integrate rather randomly into the plant genome. we analyzed a target site in the genome of nicotiana tabacum before and after integration of a t-dna. clones presenting right and left t-dna/plant dna junctions were used as probes to identify and isolate a unique 1.8-kilobase ecori fragment corresponding to the plant dna target site for a t-dna insertion event. comparison of the nucleotide sequences of the p ...	1987	16578815
phenotypic assay for excision of the maize controlling element ac in tobacco.	we describe a phenotypic assay designed to detect excision of the maize controlling element ac from a selectable marker gene, neomycin phosphotransferase ii (npt ii). an npt ii gene which expresses kanamycin resistance in tobacco cells, and contains a unique restriction enzyme site in the untranslated leader region, was constructed. ac, or a defective ac element (ac big up tri, open), was inserted into the leader region of this gene. the transposon insertions inactivated the npt ii gene as deter ...	1987	16453771
synthesis and protein body deposition of maize 15-kd zein in transgenic tobacco seeds.	the maize 15-kd zein structural gene was placed under the regulation of french bean beta-phaseolin gene flanking regions. agrobacterium tumefaciens-mediated transformation was used to insert the chimeric phaseolin-zein gene into the tobacco genome. transgenic plants synthesized zein in a tissue-specific manner during the latter half of seed development. transcription of the chimeric gene was initiated in phaseolin-derived sequences, and was terminated within the phaseolin gene 3' flanking region ...	1987	16453803
cytokinin stress changes the developmental regulation of several defence-related genes in tobacco.	tobacco shoots exposed to elevated endogenous or exogenous cytokinin levels are unable to develop roots and lack apical dominance. we have isolated cdna copies of five mrna species that accumulate to elevated levels in such cytokinin-stressed shoots via differential screening of a cdna library of transgenic shoots which contain an active t-dna cytokinin gene (t-cyt gene) from agrobacterium tumefaciens. four of the cdna clones were found to correspond to plant defence-related mrnas, encoding exte ...	1987	16453810
population heterogeneity of agrobacterium tumefaciens in galls of populus l. from a single nursery.	this study focused on the natural crown gall infections occurring in a leuce poplar nursery. soil effects on crown gall frequency were detected, indicating that contamination was due to a resident agrobacterium tumefaciens population, which was present before seedling plantation. the crown gall frequency on poplar progenies varied from 3 to 67%, indicating the feasibility of improvement in crown gall resistance. of 129 tumor isolates, 128 were pathogenic. these isolates were of biotype 1 or 2. b ...	1987	16347314
diversity among opine-utilizing bacteria: identification of coryneform isolates.	bacteria were isolated from soil and crown gall tumors by selection in minimal medium with an opine, such as succinamopine or mannopine, as the sole carbon source. the isolates were characterized for the pattern of opine utilization and identified. they were classified as mannityl opine or imino diacid utilizers and exhibited specificity of utilization similar to that described previously for agrobacterium species. a minority of isolates were gram negative and were identified as agrobacterium or ...	1987	16347383
effect of plasmid psa and of auxin on attachment of agrobacterium tumefaciens to carrot cells.	when the plasmid psa is introduced into agrobacterium tumefaciens, its presence results in the suppression of bacterial virulence. a. tumefaciens(psa) cells are virulent on bryophyllum diagremontiana only when inoculated with auxin. a. tumefaciens(psa) cells also bind to plant cells only in the presence of auxin. the effect of auxin is on the bacteria rather than on the plant cells, since the bacteria require auxin to bind to heat-killed carrot cells. bacteria containing psa and grown in the abs ...	1987	16347473
localization of sequences in wheat endosperm protein genes which confer tissue-specific expression in tobacco.	the developing cereal grain accumulates large quantities of proteins which are unique to the endosperm tissue. the dna sequences which determine their endosperm-specific expression have not yet been identified. in the absence of a suitable transformation-regeneration system for cereals, we have investigated whether chimaeric genes consisting of low mol. wt (lmw) and high mol. wt (hmw) glutenin gene upstream sequences coupled to the coding region of the bacterial chloramphenicol acetyl transferas ...	1987	15467781
segregation of genes transferred to one plant cell from two separate agrobacterium strains.	agrobacterium tumefaciens and agrobacterium rhizogenes are soil bacteria which transfer dna (t-dna) to plant cells. two agrobacterium strains, each with a different t-dna, can infect plants and give rise to transformed tissue which has markers from both t-dnas. although marker genes from both t-dnas are in the tissue, definitive proof that the tissue is a cellular clone and that both t-dnas are in a single cell is necessary to demonstrate cotransformation. we have transferred two distinguishable ...	1987	24301306
assessment of the efficiency of cotransformation of the t-dna of disarmed binary vectors derived from agrobacterium tumefaciens and the t-dna of a. rhizogenes.	co-transfer of agrobacterium rhizogenes t-dna and t-dna from the a. tumefaciens binary vector pbin19 (bevan, 1984) was studied in detail using nicotiana rustica. high frequencies of co-transfer of t-dna's were observed, even when no selection pressure was exerted. increased levels of pbin19 t-dna were found in hairy root cultures with selection at higher levels of kanamycin sulphate (50-200 μg ml(-1)). several other species were also transformed by a. rhizogenes carrying pbin19 and a. rhizogenes ...	1987	24277194
transformation of lettuce (lactuca sativa) mediated by agrobacterium tumefaciens.	lactuca sativa can be routinely transformed using ti plasmids of agrobacterium tumefaciens containing a chimeric kanamycin resistance gene (nos.nptii.nos). critical experimental variables were plant genotype, bacterial concentration, presence of a nurse culture and timing of transfers between tissue culture media. transformation was confirmed by the ability to callus and root in the presence of kanamycin, nopaline production, and by hybridization in southern blots. transformation has been achiev ...	1987	24248927
the pseudomonas savastanoi tryptophan-2-mono-oxygenase is biologically active in nicotiana tabacum.	it has been proposed that the "eukaryotic" t-dna-encoded indole-3-acetic acid (iaa) biosynthesis genes of agrobacterium tumefaciens and their prokaryotic counterpart in pseudomonas savastanoi originated from common ancestor genes. this paper provides additional evidence for the functional similarity between the gene products. we have demonstrated that a chimeric gene consisting of the coding sequence of the p. savastanoi tryptophan-2-mono-oxygenase (iaam gene) and a plant promoter encodes an act ...	1987	24226077
auxin-induced rapid changes in translatable mrnas in tobacco cell suspension.	when 2,4-dichlorophenoxyacetic acid (2,4-d)-dependent tobacco cell suspensions, one normal and one transformed by agrobacterium tumefaciens, were subcultured on hormone-lacking medium the stationary phase of the cell cycle was reached earlier than on medium containing 2,4-d. addition of the auxin 2,4-d could restore cell division activity within 10-12 h for the most rapidly reacting cell line. the cell-division response was characterized as being auxin-specific and optimal with 2,4-d at 2.2 10(- ...	1987	24226071
molecular characterization of the virulence gene vira of the agrobacterium tumefaciens octopine ti plasmid.	the virulence loci play an essential role in tumor formation by agrobacterium tumefaciens. induction of vir gene expression by plant signal molecules is solely dependent on the virulence loci vira and virg. this study focused on the vira locus of the octopine type ti plasmid pti15955. the nucleic acid sequence of a 5.7-kilobase fragment encompassing vira was determined. genetic analysis of this region revealed that vira contains one open reading frame coding for a protein of 91 639 daltons. immu ...	1987	24277199
genetic transformation of flax (linum usitatissimum) by agrobacterium tumefaciens: regeneration of transformed shoots via a callus phase.	genetic transformation of flax (linum usitatissimum) has been achieved using an a. tumefaciens strain carrying a non-oncogenic ti plasmid-derived vector containing a chimaeric npt-ii gene and a wild type nopaline synthase gene. fertile, transformed shoots were most easily obtained from km(r) callus developing on hypocotyl sections. the totipotency of the km(r) callus was dependent upon its origin. t-dna was visualised by southern blotting in all km(r) tissues. efficient expression of nopaline sy ...	1987	24248856
transformation of brassica napus with agrobacterium tumefaciens based vectors.	a reproducible system to produce transgenic brassica napus plants has been developed using stem segments. stem segments from 6-7 week old plants were inoculated with an agrobacterium tumefaciens strain containing a disarmed tumor-inducing plasmid ptit37-se carrying a chimeric bacterial gene encoding kanamycin resistance (pmon200). stem explants were cocultured for 2 days before transfer to kanamycin selection medium. shoots regenerated directly from the explant in 3-6 weeks and were excised, dip ...	1987	24248835
genetic transformation in two potato cultivars with t-dna from disarmed agrobacterium.	derivatives of potato (solanum tuberosum cv.'s 'maris bard' and 'desiree') transformed with disarmed t-dna from genetically engineered agrobacterium tumefaciens strains were isolated. the transformed plants were recovered from shoot-forming tumours induced by infection of wounds with mixedcultures of shoot-inducing a. tumefaciens strains t37 and either agrobacterium strain lba1834(pral1834), (hille et al. 1983) or lba4404(pbin6; pral4404), (bevan 1984). two small-scale feasibility experiments ga ...	1987	24241200
initiation of auxin autonomy in nicotiana glutinosa cells by the cytokinin-biosynthesis gene from agrobacterium tumefaciens.	agrobacteria carrying mutations at the auxin-biosynthesizing loci (iaah and iaam of the ti plasmid) induce shoot-forming tumors on many plant species. in some cases, e.g. nicotiana glutinosa l., tumors induced by such mutant strains exhibit an unorganized and fully autonomous phenotype. these characteristics are stable in culture at both the tissue and cellular level. we demonstrate that the cytokinin-biosynthesis gene (ipt) of the ti plasmid is responsble for the induction of both auxin and cyt ...	1987	24225718
acetosyringone promotes high efficiency transformation of arabidopsis thaliana explants by agrobacterium tumefaciens.	high frequency transformation of arabidopsis thaliana leaf explants has been obtained using a disarmed ti plasmid containing the coding region of a neomycin phosphotransferase gene (npt ii) as a selectable marker. the rate of transformation ranged from 55 to 63 percent when acetosyringone (as), a natural wound response molecule, was added to an agrobacterium tumefaciens culture prior to incubation with leaf segments. without acetosyringone, the transformation rate was approximately 2 to 3 percen ...	1987	24301191
expression of a soybean β-conclycinin gene under the control of the cauliflower mosaic virus 35s and 19s promoters in transformed petunia tissues.	a gene encoding the α'-subunit of β-conglycinin was ligated to the 19s and 35s promoters of cauliflower mosaic virus and introduced into petunia plants on a disarmed ti-plasmid using agrobacterium tumefaciens. transformed cells were regenerated into whole plants and ummunoreactive polypeptides and hybridizable, polyadenylated mrna were detected in transformed tissues. expression from the 35s promoter was 10 to 50 times greater than expression from the 19s promoter. the level of immunodetectable ...	1987	24277084
correlation between binding of agrobacterium tumefaciens by root cap cells and susceptibility of plants to crown gall.	we compared the binding of agrobacterium tumefaciens by freshly isolated root cap cells with susceptibility of plants to crown gall tumorigenesis. a high binding reaction was strongly correlated with susceptibility to tumorigenesis in a survey of the binding of strain b6 to cells from 48 species in 17 families. in reciprocal experiments with nine virulent a. tumefaciens strains, tumors developed in plant-bacteria combinations that gave a high binding response in the root cap cell assay. binding ...	1987	24248761
endogenous indoles and the biosynthesis and metabolism of indole-3-acetic acid in cultures of rhizobium phaseoli.	gas chromatography-mass spectrometric analyses of purified extracts from cultures of rhizobium phaseoli wild-type strain 8002, grown in a non-tryptophan-supplemented liquid medium, demonstrated the presence of indole-3-acetic acid (iaa), indole-3-ethanol (iet), indole-3-aldehyde and indole-3-methanol (im). in metabolism studies with (3)h-, (14)c- and (2)h-labelled substrates the bacterium was shown to convert tryptophan to iet, iaa and im; iet to iaa and im; and iaa to im. indole-3-acetamide (ia ...	1987	24227443
structure, organization and expression of transferred dna in nicotiana plumbaginifolia crown-gall tissues.	data are provided which show that transferred dna (t-dna) present in nicotiana plumbaginifolia crown-gall lines in most cases was scrambled and not intact. both wild-type, and 'rooter'- and 'shooter'-type mutants of octopine-type agrobacterium tumefaciens were used to infect n. plumbaginifolia plantlets, cultured in vitro. resulting tumors were excised from the plantlets and cultured for more than three years. during subculturing the tumor lines were scored for the following phenotypic traits: p ...	1987	24227439
transformation of stylosanthes spp. using agrobacterium tumefaciens.	tumours were incited on leaf sections of stylosanthes humilis, s. hamata, s. guianensis and s. scalra following infection by agrobacterium tumefaciens. the suitability of 2 binary vectors (pga472, bin6) for gene transfer in s. humilis was tested and kanamycin-resistant tumour tissue was obtained from infected leaf pieces. the presence and expression of the neomycin phosphotransferase (npt ii) gene in the plant cells was demonstrated by hybridization of the coding region of the npt ii gene of the ...	1987	24248653
callus induction from protoplasts of v. unguiculata, v. sublobata and v. mungo.	protoplasts were isolated from hypocotyl of v. mungo (l.) hepper or hypocotyl-derived callus of v. sublobata (phaseolus sublobata roxb.) and v. unguiculata (l.) walp (syn. v. sinensis (l.) saviex hassk) using an enzyme solution comprising cellulase 2.5%, macerozyme, hemicellulase and driselase each at a 0.5% level in 0.5 m sorbitol. isolated protoplasts were cultured in murashige and skoog's (1962) basal liquid medium supplemented with ba, naa, 2,4-d (1 mg/l each) and sucrose (14%). after four w ...	1987	24241464
transformation of cotton (gossypium hirsutum l.) by agrobacterium tumefaciens and regeneration of transgenic plants.	cotton (gossypium hirsutum l.) cotyledon tissues have been efficiently transformed and plants have been regenerated. cotyledon pieces from 12-day-old aseptically germinated seedlings were inoculated with agrobacterium tumefaciens strains containing avirulent ti (tumor-inducing) plasmids with a chimeric gene encoding kanamycin resistance. after three days cocultivation, the cotyledon pieces were placed on a callus initiation medium containing kanamycin for selection. high frequencies of transform ...	1987	24277496
transformation of soybean protoplasts from permanent suspension cultures by cocultivation with cells of agrobacterium tumefaciens.	cell wall regenerating protoplasts from soybean cells kept in suspension culture were cocultivated with bacteria which were derived from the nopaline strain c58 of agrobacterium tumefaciens. when the bacteria carried an oncogenic ti-plasmid, about 5% of the surviving protoplasts were able to form calli on hormone-free agar in contrast to controls, where bacteria without ti-plasmid were applied, and where no calli were formed. after isolation of dna from hormone-independently growing cells furthe ...	1987	24276903
chromosomal nodulation genes: sym-plasmid containing agrobacterium strains need chromosomal virulence genes (chva and chvb) for nodulation.	the chromosomal genes chva and chvb of agrobacterium tumefaciens, which mediate attachment to plant cells, were found to be essential not only for tumour induction but also for the formation of root nodules on plants.	1987	24302529
functional analysis of the agrobacterium tumefaciens octopine ti-plasmid left and right t-region border fragments.	border fragments of the octopine ti-plasmid were tested for their ability to restore tumorigenicity of an avirulent mutant carrying a deleted right border. it was found that neither introduction of left border fragments nor that of small right border fragments at the position of the deletion resulted in a complete restoration of oncogenicity. however, insertion of a larger right border fragment in the deletion mutant gave fully oncogenic strains. in the latter case sequences to the right side of ...	1987	24302528
t-dna rearrangements due to tissue culture: somaclonal variation in crown gall tissues.	after three years of apparent stability in tissue culture, the single cell derived shooty crown gall line snt1.013 produced a revertant shoot which had switched from non-rooting (rod(+)) and octopine synthesizing (ocs(+)) to rod(-) ocs(-), indicating that in this revertant tl-dna genes 4 (causing the rod(+) trait) and gene 3 (causing the ocs(+) trait) had been inactivated. southern blots revealed that the inactivation of these t-dna genes was the result of a considerable rearrangement of dna seq ...	1987	24276797
colonization of tomato plants by two agrocin-producing strains of agrobacterium tumefaciens.	for a bacterium to be a successful biocontrol agent against crown gall disease, it must produce an effective agrocin specific for agrobacterium tumefaciens and be able to colonize host plants efficiently. the colonization abilities of k84 and j73, successful and potential biocontrolling strains, respectively, were compared both in vivo and in vitro. both strains produced fibrils attaching them to tomato root surfaces and had similar colonization efficiencies up to 14 days after inoculation. howe ...	1988	16347802
cauliflower mosaic virus gene vi produces a symptomatic phenotype in transgenic tobacco plants.	gene vi of the cauliflower mosaic virus (camv) genome encodes a protein (p(66)) in virus-infected plants that accumulates in cytoplasmic inclusion bodies. when a segment of the camv genome bearing gene vi is transferred to tobacco plants by the agrobacterium tumefaciens ti plasmid, the resulting transgenic plants display viral-like symptoms. symptoms produced by the dna from two different viral isolates (camv cabb b-ji and cm1841) were distinct-symptoms from the first were mosaic-like, whereas t ...	1988	16578828
factor inducing agrobacterium tumefaciens vir gene expression is present in monocotyledonous plants.	agrobacterium tumefaciens harboring the tumor-inducing ti plasmid incites crown gall tumor on dicotyledonous species. upon infection of these plants, ti plasmid dna sequence is stably transferred (t-dna) by unknown mechanisms to plant cells to be integrated into nuclear dna. the t-dna processing and transfer require the expression of vir (virulence) genes on the ti plasmid, which are known to be induced by certain phenolic compounds released from cells at the wounded inoculation site. the result ...	1988	16593930
isolation of genes involved in nodulation competitiveness from rhizobium leguminosarum bv. trifolii t24.	rhizobium leguminosarum bv. trifolii t24 produces a potent anti-rhizobial compound, trifolitoxin, and exclusively nodulates clover roots when in mixed inoculum with trifolitoxin-sensitive strains of r. leguminosarum bv. trifolii [schwinghamer, e. a. & belkengren r. p. (1968) arch. mikrobiol. 64, 130-145]. in the present study, the isolation of trifolitoxin production and resistance genes is described. a cosmid genomic library of t24 was prepared in plafr3. no trifolitoxin expression was observed ...	1988	16593933
an enhancer-like element present in the promoter of a t-dna gene from the ti plasmid of agrobacterium tumefaciens.	the promoter of the 780 gene of t-right [thomashow, m., nutter, r., montoya, a., gordon, m. & nester, e. (1980) cell 19, 729-739] from agrobacterium tumefaciens ti plasmid (pti15955) was shown to contain an upstream cis-acting element (activator) having enhancer-like properties. to characterize the properties of this promoter element, it was placed in both polarities, upstream and downstream of a delta-37 deletion mutant of the 780 gene. the delta-37 deletion contains the entire 780 gene with th ...	1988	16593943