Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| localization of agrobacterium rhizogenes t-dna in plant chromosomes by in situ hybridization. | we have used in situ hybridization to determine the sites of insertion of agrobacterium rhizogenes ri t-dna in the chromosomes of crepis capillaris (2n = 6) transformed roots. four transformed root lines were obtained by infecting crepis stem segments with a. rhizogenes. southern hybridization analysis indicated that each root line was the result of one or more independent t-dna insertion events. in two root lines, one copy of t-dna was present; the other two root lines each contained two copies ... | 1986 | 16453703 |
| a plant cell factor induces agrobacterium tumefaciens vir gene expression. | the virulence genes of agrobacterium are required for this organism to genetically transform plant cells. we show that vir gene expression is specifically induced by a small (<1000 da) diffusible plant cell metabolite present in limiting quantities in the exudates of a variety of plant cell cultures. active plant cell metabolism is required for the synthesis of the vir-inducing factor, and the presence of bacteria does not stimulate this production. vir-inducing factor is (i) heat and cold stabl ... | 1986 | 16593648 |
| "agroinfection," an alternative route for viral infection of plants by using the ti plasmid. | most plant viruses are transmitted by insect vectors. we present an alternative method for the introduction of infectious viral dna that uses the ability of agrobacterium to transfer dna from bacterial cells to plants. cauliflower mosaic virus was chosen to develop this method because it is the best characterized plant dna virus and can be introduced into plants via aphids, virus particles, viral dna, or suitably treated cloned dna. we show that systemic infection of turnips results from woundin ... | 1986 | 16593697 |
| rhizobium meliloti genes required for nodule development are related to chromosomal virulence genes in agrobacterium tumefaciens. | symbiotically essential genes have been identified in rhizobium meliloti that are structurally and functionally related to chromosomal virulence (chv) genes of agrobacterium tumefaciens. homologous sequences also exist in the genomes of other fast-growing rhizobia including rhizobium trifolii, rhizobium leguminosarum, and rhizobium phaseoli. in agrobacterium, the chva and chvb loci are known to be essential for oncogenic transformation of dicotyledonous plants and for attachment to plant cells [ ... | 1986 | 16593714 |
| rapid assay of foreign gene expression in leaf discs transformed by agrobacterium tumefaciens: role of t-dna borders in the transfer process. | we have developed a sensitive leaf disc transformation procedure for studying early and/or transient t-dna expression during agrobacterium tumefaciens-mediated transformation of plant cells. using this system, we have examined the function of t-dna border sequences on the early expression of t-dna genes and on the stable integration of those genes in infected cells. deletion of the right border from the t-dna appears to permit transfer of t-dna genes from the tumor-inducing (ti) plasmid but grea ... | 1986 | 16593716 |
| complementation of agrobacterium tumefaciens tumor-inducing aux mutants by genes from the t(r)-region of the ri plasmid of agrobacterium rhizogenes. | in this paper we provide information indicating that the agropine-type root-inducing (ri) plasmid pri1855 of agrobacterium rhizogenes contains functional genes for auxin production (aux) in the right transferred dna (t-dna) region (t(r)-region). these genes were cloned and introduced into the t-region of the tumor-inducing (ti) plasmids of mutants of agrobacterium tumefaciens carrying an aux mutation. depending on the ri aux gene present, the oncogenicity of the ti aux-1 and/or aux-2 mutations w ... | 1986 | 16593762 |
| insertion sequence elements of pseudomonas savastanoi: nucleotide sequence and homology with agrobacterium tumefaciens transfer dna. | two types of transposable elements, is51 and is52 (is, insertion sequence), were found in pseudomonas syringae subsp. savastanoi (p. savastanoi) that spontaneously insert into and inactivate iaam; the insertion results in the loss of indoleacetic acid production and attenuation of virulence. the nucleotide sequences of both is elements have sizes and structural features common to other prokaryotic is elements; is51 is 1311 base pairs (bp) long and has terminal inverted repeats of 26 bp; is52 is ... | 1986 | 16593778 |
| overdrive, a t-dna transmission enhancer on the a. tumefaciens tumour-inducing plasmid. | during crown gall tumorigenesis a specific segment of the agrobacterium tumefaciens tumour-inducing (ti) plasmid, the t-dna, integrates into plant nuclear dna. similar 23-bp direct repeats at each end of the t region signal t-dna borders, and t-dna transmission (transfer and integration) requires the right-hand direct repeat. a chemically synthesized right border repeat in its wild-type orientation promotes t-dna transmission at a low frequency; ti plasmid sequences which normally flank the righ ... | 1986 | 15966101 |
| transient and stable expression of the firefly luciferase gene in plant cells and transgenic plants. | the luciferase gene from the firefly, photinus pyralis, was used as a reporter of gene expression by light production in transfected plant cells and transgenic plants. a complementary dna clone of the firefly luciferase gene under the control of a plant virus promoter (cauliflower mosaic virus 35s rna promoter) was introduced into plant protoplast cells (daucus carota) by electroporation and into plants (nicotiana tabacum) by use of the agrobacterium tumefaciens tumor-inducing plasmid. extracts ... | 1986 | 17758108 |
| transformation of arabidopsis thaliana with agrobacterium tumefaciens. | transformed arabidopsis thaliana plants have been produced by a modified leaf disk transformation-regeneration method. leaf pieces from sterilely grown plants were precultured for 2 days and inoculated with an agrobacterium tumefaciens strain containing an avirulent ti (tumor-inducing) plasmid with a chimeric gene encoding hygromycin resistance. after cocultivation for 2 days, the leaf pieces were placed on a medium that selects for hygromycin resistance. shoots regenerated within 3 months and w ... | 1986 | 17792019 |
| transfer of agrobacterium dna to plants requires a t-dna border but not the vire locus. | agrobacterium tumefaciens induces tumors in plants by transferring and integrating oncogenes (t-dna) into the chromosomes of host plant cells. agrobacterium strains were used to transfer complementary dna copies of a potato spindle tuber viroid (pstv) to plant cells at a wound site on tomato plant stems. subsequently, infectious viroid rna was found in the leaves of these plants, indicating systemic pstv infection. this process utilized the t-dna transfer mechanisms of agrobacterium since pstv i ... | 1986 | 17800798 |
| the initiation of auxin autonomy in tissue from tobacco plants carrying the auxin biosynthesizing genes from the t-dna of agrobacterium tumefaciens. | tobacco (nicotiana tabacum cv havana 425) plants containing the indole-3-acetic acid biosynthesizing genes (1 and 2) from the t-dna of agrobacterium tumefaciens strain t37-adh(2) (mutated at the cytokinin biosynthesis gene 4) were used to study the physiological basis of the suppression and reinitiation of the auxin autonomous phenotype. the plants, though normal in appearance and cross-fertile with nontransformed, wild type tobacco, are shown to contain multiple copies of genes 1 and 2. plants ... | 1986 | 16664572 |
| bound auxin metabolism in cultured crown-gall tissues of tobacco. | bound auxin metabolism in cultured crown-gall tumor cells and pith callus of tobacco was examined by feeding radiolabeled auxins and auxin conjugates. in all tissues fed [(14)c]indoleacetic acid (iaa), at least one-third of the iaa was decarboxylated, and most of the remaining radiolabel occurred in a compound(s) which did not release iaa with alkaline hydrolysis. in cells transformed by the a6 strain of agrobacterium tumefaciens, the only detectable iaa conjugate was indole-3-acetylaspartic aci ... | 1986 | 16664620 |
| transformation of tobacco, tomato, potato, and arabidopsis thaliana using a binary ti vector system. | using a binary tumor-inducing (ti) plasmid vector system, several plant species were transformed with a kanamycin resistance marker (neomycin phosphotransferase gene). four nicotiana species, seven tomato cultivars, two potato cultivars, and arabidopsis thaliana were transformed by the binary vector transformation method. in this method, various plant organ pieces were co-cultivated with agrobacterium tumefaciens cells carrying the binary vector, pga472, and a helper ti plasmid. we have also dem ... | 1986 | 16664795 |
| development of plant promoter expression vectors and their use for analysis of differential activity of nopaline synthase promoter in transformed tobacco cells. | i have developed promoter expression binary vectors based on the tumor-inducing plasmid of agrobacterium tumefaciens to facilitate elucidation of plant gene regulation. promoter activity can be determined by inserting dna fragments into the multiple cloning sites of the vectors forming transcriptional and/or translational fusions between the cat structural gene and an inserted promoter region. the activity of the nopaline synthase (nos) promoter was demonstrated with the vector. however, three a ... | 1986 | 16664813 |
| opine synthesis in wild-type plant tissue. | opine production is associated with crown gall tissue, a neoplastic growth caused by infection of dicotyledonous plants with agrobacterium tumefaciens. recent publications have claimed that tissues of certain monocotyledonous plants can also be infected by agrobacterium. following infection, a part of the agrobacterium ti plasmid, t-dna, is integrated into the chromosome of the infected plant. t-dna, which codes for opine-synthesizing enzymes, is now used to add foreign genes to plants. a number ... | 1986 | 16664995 |
| response of various cucurbits to infection by plasmid-harboring strains of agrobacterium. | tumor formation in cucurbit cultivars resulting from infection by various strains of agrobacterium tumefaciens and agrobacterium rhizogenes is environmentally affected. in all instances, tumors could be induced on excised cotyledons while inoculating attached cotyledons or stems resulted in no tumor formation. in addition, buttercup squash (cucurbita maxima duch. buttercup) was most susceptible to tumor formation, while butterbush squash (cucurbita maxima duch. butterbush) failed to form tumors ... | 1986 | 16665082 |
| secretion of zeatin, ribosylzeatin, and ribosyl-1'' -methylzeatin by pseudomonas savastanoi: plasmid-coded cytokinin biosynthesis. | cytokinin production by strains of the phytopathogenic bacterium pseudomonas syringae pv savastanoi was measured by immunoaffinity chromatography of the culture medium on immobilized anti-cytokinin antibodies, followed by high performance liquid chromatography, radioimmunoassay and mass spectrometry. p. savastanoi strain pb213-2 secretes zeatin (80 nanograms per milliliter) and ribosylzeatin (80 nanograms per milliliter). even higher levels of zeatin (400 nanograms per milliliter) are produced b ... | 1986 | 16665104 |
| agrobacterium-mediated gene transfer results mainly in transgenic plants transmitting t-dna as a single mendelian factor. | forty-four independent transformed tobacco plants were obtained from a cocultivation experiment with agrobacterium tumefaciens strains carrying modified ti-plasmids. the transformed plants were either self-fertilized or crossed with nontransformed plants or with other transformed plants. the segregation of a phenotypic marker (kanamycin resistance) in the progenies of these plants was determined. in 40 cases out of 44, the segregation of the kanamycin resistance marker is consistent with mendeli ... | 1986 | 17246346 |
| 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 |
| organ-specific and dosage-dependent expression of a leaf/stem specific gene from potato after tagging and transfer into potato and tobacco plants. | st-ls1, a single copy gene from potato displaying a leaf/stem specific gene expression, was tagged by an exon modification and introduced into both potato and tobacco cells using agrobacterium vectors. after regeneration of whole plants, the expression of the tagged gene was analyzed with respect to its organ specificity and compared to the expression of the corresponding resident gene. the expression of the transferred gene in transgenic plants closely followed the expression of the resident ge ... | 1987 | 3575098 |
| 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 |
| 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 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 |
| 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 |
| 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 |
| agrobacterium rhizogenes as a vector for transforming higher plants. | agrobacterium rhizogenes is a natural vector for genetically transforming higher plants. a protocol is given for using this system to insert foreign genes into host plants. improvements currently being developed in several laboratories are also discussed. | 1987 | 3153165 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 | |
| physical map of the t-dna region of agrobacterium rhizogenes strain ncppb2659. | the t-dna region of the plasmid responsible for hairy root in the agrobacterium rhizogenes strain ncppb2659 is identified and characterized by its physical map. | 1987 | 2827205 |
| 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 |
| 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 |
| 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 |
| 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 |
| agrobacterium rhizogenes t-dna genes capable of inducing hairy root phenotype. | segments of the tl-dna of the agropine type ri plasmid pri 1855 encompassing single and groups of open-reading frames were cloned in the ti plasmid-derived binary vector system bin 19. leaf disc infections on nicotiana tabacum led to transformed plants, some of which showed typical hairy root phenotypes, such as the wrinkled leaf morphology, excessive and partially non geotropic root systems and the ability of leaf explants to differentiate roots in a hormone-free culture medium. particularly in ... | 1987 | 17193709 |
| 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 |
| production of hyoscyamine by 'hairy root' cultures of datura stramonium. | 'hairy root' cultures of datura stramonium were established following infection of aseptic leaves with agrobacterium rhizogenes. transformation was confirmed by southern blotting using [ (32)p]-labelled fragments of the t-dna as probes. the transformed cultures grew in the absence of added phytohormones and cell mass increased 55-fold during 28 days incubation. hyoscyamine was a major component of the alkaloid fraction and accounted for at least 0.3% of the dry matter, comparable to pot-grown pl ... | 1987 | 17269071 |
| 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 |
| comparison of the growth promoting activities and toxicities of various auxin analogs on cells derived from wild type and a nonrooting mutant of tobacco. | a naphthaleneacetic acid tolerant mutant isolated from a mutagenized culture of tobacco mesophyll protoplasts and impaired in root morphogenesis has been previously characterized by genetic analysis. to understand the biochemical basis for naphthaleneacetic acid resistance, cells derived from this mutant and from wild-type tobacco were compared for their ability to respond to various growth regulators. the growth promoting abilities and cytotoxicities of auxin analogs were different for mutant a ... | 1987 | 16665341 |
| 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 |
| 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 |
| transgenic plants as tools to study the molecular organization of plant genes. | transgenic plants are generated in nature by agrobacterium tumefaciens, a pathogen that produces disease through the transfer of some of its own dna into susceptible plants. the genes are carried on a plasmid. much has been learned about how the plasmid is transferred, how the plasmid-borne genes are organized, regulated, and expressed, and how the bacteria's pathogenic effects are produced. the a. tumefaciens plasmid has been manipulated for use as a general vector for the transfer of specific ... | 1987 | 17801640 |
| the 30-kilodalton gene product of tobacco mosaic virus potentiates virus movement. | the proposed role of the 30-kilodalton(kd) protein of tobacco mosaic virus is to facilitate cell-to-cell spread of the virus-during infection. to directly define the function of the protein, a chimeric gene containing a cloned complementary dna of the 30-kd protein gene was introduced into tobacco cells via a ti plasmid-mediated transformation system of agrobacterium tumefaciens. transgenic plants regenerated from transformed tobacco cells expressed the 30-kd protein messenger rna and accumulate ... | 1987 | 17794341 |
| 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 |
| erratum. | in the report "site-specific nick in the t-dna border sequence as a result of agrobacterium vir gene expression" by k. wang et al. (30 jan., p. 587), figure 2a on page 588 should have shown a 3.2-kilobase band in lane b that was not visible. also, 1.9-kilobase bands in lane c and g were not visible. a print that shows the bands in figure 2, a and b, appears below. in addition, reference 24 should have been to j. l. slightom, l. jouanin, f. leach, r. f. drong, d. tepfer, embo j. 4, 3069 (1985). [ ... | 1987 | 17774996 |
| site-specific nick in the t-dna border sequence as a result of agrobacterium vir gene expression. | the t-dna transfer process of agrobacterium tumefaciens is activated by the induction of the expression of the ti plasmid virulence (vir) loci by plant signal molecules such as acetosyringone. the vir gene products act in trans to mobilize the t-dna element from the bacterial ti plasmid. the t-dna is bounded by 25-base pair direct repeat sequences, which are the only sequences on the element essential for transfer. thus, specific reactions must occur at the border sites to generate a transferabl ... | 1987 | 17758248 |