Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| vectors for plant transformation and cosmid libraries. | a series of vectors has been constructed for the purpose of introducing cloned dnas into plant genomes, using agrobacterium tumefaciens-mediated transformation methods. one of these vectors, pcit20, is a plasmid that contains a multiple cloning site (mcs), and a marker (hph) that confers hygromycin resistance to plant cells. the others are all cosmid vectors which allow insertion of up to 46 kb of plant genomic dna, and which also contain all of the necessary sequences for a. tumefaciens-mediate ... | 1992 | 1639265 |
| nolc, a rhizobium fredii gene involved in cultivar-specific nodulation of soybean, shares homology with a heat-shock gene. | rhizobium fredii strain usda257 does not nodulate soybean (glycine max (l.) merr.) cultivar mccall. mutant 257dh5, which contains a tn5 insert in the bacterial chromosome, forms nodules on this cultivar, but acetylene-reduction activity is absent. we have sequenced the region corresponding to the site of tn5 insertion in this mutant and find that it lies within a 1176bp open reading frame that we designate nolc. nolc encodes a protein of deduced molecular weight 43564. nucleotide sequences homol ... | 1991 | 1646377 |
| polypeptide composition of bacterial cyclic diguanylic acid-dependent cellulose synthase and the occurrence of immunologically crossreacting proteins in higher plants. | to comprehend the catalytic and regulatory mechanism of the cyclic diguanylic acid (c-di-gmp)-dependent cellulose synthase of acetobacter xylinum and its relatedness to similar enzymes in other organisms, the structure of this enzyme was analyzed at the polypeptide level. the enzyme, purified 350-fold by enzyme-product entrapment, contains three major peptides (90, 67, and 54 kda), which, based on direct photoaffinity and immunochemical labeling and amino acid sequence analysis, are constituents ... | 1991 | 1647035 |
| characterization of a putative periplasmic transport system for octopine accumulation encoded by agrobacterium tumefaciens ti plasmid ptia6. | neoplastic crown gall tumors incited by agrobacterium tumefaciens release novel amino acid or sugar derivatives known as opines, whose synthesis is directed by genes transferred to plant cells. agrobacterium cells can transport and catabolize these compounds as sources of carbon and nitrogen. this article describes a region of the ptia6 plasmid which is required for catabolism of the opine octopine and whose transcription is induced by octopine. this region of the plasmid contains four open read ... | 1991 | 1655707 |
| polygalacturonase is a virulence factor in agrobacterium tumefaciens biovar 3. | agrobacterium tumefaciens biovar 3 causes both crown gall and root decay of grapes. all biovar 3 strains, regardless of their tumorigenicity, produce in culture a single polygalacturonase with a pi around 4.5. a. tumefaciens biovar 3 strain cg49 was mutagenized with tn5 by using psup2021 as a suicide vector. a mutant strain, cg50, lacking polygalacturonase activity was isolated. the mutation was due to a single tn5 insertion in an 8.5-kb ecori fragment that also contained the polygalacturonase s ... | 1991 | 1655716 |
| limited host range ti plasmids: recent origin from wide host range ti plasmids and involvement of a novel is element, is868. | agrobacterium tumefaciens biotype iii octopine strains have been isolated from grapevine tumors worldwide. they comprise limited and wide host range (lhr and whr) strains that carry related tumor-inducing (ti) plasmids with two t-regions, ta and tb. the whr ta-region resembles the biotype i octopine region, whereas the lhr ta-region is a recent deletion derivative of the whr ta-region, which lacks the iaa genes and part of the ipt gene. sequencing of the ta-region of the ubiquitous lhr strain ab ... | 1991 | 1657255 |
| characterization of cytochromes c550 and c555 from bradyrhizobium japonicum: cloning, mutagenesis, and sequencing of the c555 gene (cycc). | the major soluble c-type cytochromes in cultured cells of bradyrhizobium japonicum usda 110 comprised a co-reactive c555 (mr, approximately 15,500) and a non-co-reactive c550 (mr, approximately 12,500). levels of cytochrome per gram of soluble protein in aerobic, anaerobic, and symbiotic cells were 32, 21, and 30 nmol, respectively, for c555 and 31, 44, and 65 nmol, respectively, for c550. the midpoint redox potentials (em,7) of the purified cytochromes were +236 mv for c555 and +277 mv for c550 ... | 1991 | 1660457 |
| mapping of the ros virulence regulatory gene of a. tumefaciens. | virulence functions associated with the oncogenicity of agrobacterium tumefaciens are encoded by vir genes contained in six major operons located on the ti plasmid. the virc and vird operons encode functions responsible for host range and t-intermediate processing. these two operons are regulated positively by the product of virg and negatively by the product of the chromosomal gene ros, which encodes a 15.5 kda repressor. to determine the location of the ros gene we have constructed a. tumefaci ... | 1991 | 1660566 |
| nucleotide sequence and organization of genes flanking the transfer origin of promiscuous plasmid rp4. | the nucleotide sequence of the relaxase operon and the leader operon which are part of the tra1 region of the promiscuous plasmid rp4 was determined. these two polycistronic operons are transcribed divergently from an intergenic region of about 360 bp containing the transfer origin and six close-packed genes. a seventh gene completely overlaps another one in a different reading frame. conjugative dna transfer proceeds unidirectionally from orit with the leader operon heading the dna to be transf ... | 1991 | 1665997 |
| nucleotide sequence of rhizobium meliloti insertion sequence isrm1: homology to is2 from escherichia coli and is426 from agrobacterium tumefaciens. | nucleotide sequencing of rhizobium meliloti insertion sequence isrm1 showed that it is 1319 nucleotides long and includes 32/31 nucleotide terminal inverted repeats. analysis of five different insertion sites using sequencing primers complementary to sequences within the left and right ends demonstrated that isrm1 generates five bp direct repeats at the sites of insertion. although isrm1 has shown a target preference for certain short regions (hot spots), there was no apparent similarity in the ... | 1991 | 1667984 |
| regeneration of transgenic lycium barbarum l. | a simple and effective system for the transformation and regeneration of lycium barbarum l. has been developed. young stem segments from lycium barbarum l. were infected by agrobacterium tumefaciens harboring a vector containing neomycin phosphotransferase ii (npt-ii) gene derived from non-oncogenic ti plasmid. calli originating from young stem segments on selective induction medium could differentiate into buds on selective differentiation medium rapidly and finally developed into whole plants. ... | 1991 | 1668526 |
| polymorphism of nopaline-type t-dnas from agrobacterium tumefaciens. | the structure of several t-dnas of agrobacterium tumefaciens was determined by molecular cloning and southern hybridization. the t-dnas cloned in escherichia coli vectors from four different nopaline type strains (pyte1, po31, po22, and ake10) showed various sizes of restriction enzyme fragments. comparative analysis of the restriction maps revealed that the t-dnas were composed of three distinct structural domains: (1) the region proximal to the right border (domain i) containing the portion es ... | 1991 | 1674610 |
| studies of the bradyrhizobium japonicum nodd1 promoter: a repeated structure for the nod box. | induction of nod genes in rhizobium and bradyrhizobium species is dependent on the presence of plant-produced flavonoids, the nodd protein, and the cis-acting nod box promoter sequence. although the nodd (nodd1) gene in rhizobium species is constitutively expressed, nodd1 expression in bradyrhizobium japonicum is inducible by isoflavones in a manner similar to that of the nodyabc operon. a consensus nod box sequence is found 5' of the nodyabc operon, whereas a presumptive, nod box-like sequence ... | 1991 | 1675210 |
| characterisation of a pseudomonas aeruginosa twitching motility gene and evidence for a specialised protein export system widespread in eubacteria. | type-4 fimbriae (pili) are associated with a phenomenon known as twitching motility, which appears to be involved with bacterial translocation across solid surfaces. pseudomonas aeruginosa mutants which produce fimbriae, but which have lost the twitching motility function, display altered colony morphology and resistance to fimbrial-specific bacteriophage. we have used phenotypic complementation of such mutants to isolate a region of dna involved in twitching motility. this region was physically ... | 1991 | 1676385 |
| complementation of an rnase p rna (rnpb) gene deletion in escherichia coli by homologous genes from distantly related eubacteria. | we report the construction of a strain of escherichia coli in which the only functional gene for the rna moiety of rnase p (rnpb) resides on a plasmid that is temperature sensitive for replication. the chromosomal rnase p rna gene was replaced with a chloramphenicol acetyltransferase gene. the conditionally lethal phenotype of this strain was suppressed by plasmids that carry rnase p rna genes from some distantly related eubacteria, including alcaligenes eutrophus, bacillus subtilis, and chromat ... | 1990 | 1699929 |
| transgenic rice cell lines and plants: expression of transferred chimeric genes. | cell suspension-derived rice (oryza sativa l.) protoplasts were transformed by direct gene uptake. peg-mediated transformation was more efficient than electroporation. plasmid dna containing a hygromycin phosphotransferase (hpt) gene (which confers hygromycin resistance) driven by the camv 35s promoter and a beta-d-glucuronidase (gus) gene under control of the 1', 2' double promoter of the mannopine synthase (mas) locus of agrobacterium tumefaciens was introduced into rice protoplasts. southern ... | 1991 | 1713479 |
| cross-talk between the virulence and phosphate regulons of agrobacterium tumefaciens caused by an unusual interaction of the transcriptional activator with a regulatory dna element. | transcription of a virulence gene on the hairy-root-inducing plasmid a4, which is induced by plant factors in agrobacterium tumefaciens, was also activated by phosphate limitation in both a. tumefaciens and escherichia coli. the starting site of rna synthesized under the two inducing conditions was the same, and an identical promoter was responsible for both inducible expressions. the response of the virulence gene to phosphate limitation did not require the positive regulator virg for the virul ... | 1991 | 1714035 |
| integration and expression of a rabbit liver cytochrome p-450 gene in transgenic nicotiana tabacum. | cytochrome p-450 is involved in the oxidative metabolism of a broad range of substrates. we have made a chimeric construct, psn002, containing the cdna for rabbit liver cytochrome p-450 (iic14) under the control of the tr2' promoter for mannopine synthase in the agrobacterium ti plasmid. nicotiana tabacum was transformed with agrobacterium tumefaciens harboring a cointegrated plasmid psn002::pgv2260. the presence of mrna and of the translated protein from the chimeric cytochrome p-450 gene in tr ... | 1991 | 1714583 |
| expression of cowpea mosaic virus coat protein precursor in transgenic tobacco plants. | tobacco, nicotiana tabacum l., supports cowpea mosaic virus (cpmv) replication and cell-to-cell movement, and thus may serve as a model system to study coat protein-mediated protection against cpmv. a chimeric gene consisting of the cauliflower mosaic virus 35s promoter, cpmv 60k coat proteins-precursor (cp-p) coding region, and the nopaline synthase polyadenylation signal was transferred to tobacco cv. burley 21 via the agrobacterium tumefaciens binary vector system. gene integration and expres ... | 1992 | 1730936 |
| opine catabolism and conjugal transfer of the nopaline ti plasmid ptic58 are coordinately regulated by a single repressor. | the ti plasmids of agrobacterium tumefaciens are conjugal elements whose transfer is strongly repressed. transfer is induced by the conjugal opines, a group of unique carbon compounds synthesized in crown gall tumors. the opines also induce ti plasmid-encoded genes required by the bacteria for opine catabolism. we have cloned and sequenced a gene from the ti plasmid ptic58, whose product mediates the opine-dependent regulation of conjugal transfer and catabolism of the conjugal opines, agrocinop ... | 1992 | 1731335 |
| opine transport genes in the octopine (occ) and nopaline (noc) catabolic regions in ti plasmids of agrobacterium tumefaciens. | the occ and noc regions of octopine and nopaline ti plasmids in agrobacterium tumefaciens are responsible for the catabolic utilization of octopine and nopaline, respectively. opine-inducible promoters, genes for regulatory proteins and for catabolic enzymes, had been identified in previous work. however, both regions contained additional dna stretches which were under the control of opine-inducible promoters, but the functions were unknown. we investigated these stretches by dna sequence and fu ... | 1992 | 1732218 |
| characterization of the agrobacterium tumefaciens heat shock response: evidence for a sigma 32-like sigma factor. | we have characterized the heat shock response of agrobacterium tumefaciens and compared it with the well-characterized escherichia coli heat shock response. four major heat shock proteins with apparent molecular masses of 98, 75, 65, and 20 kda were identified by pulse-labelling cultures after temperature upshift. the three largest proteins comigrated with proteins that were antigenically related to the e. coli heat shock proteins sigma 70, dnak, and groel, respectively. the heat shock proteins ... | 1992 | 1732231 |
| mutation of the miaa gene of agrobacterium tumefaciens results in reduced vir gene expression. | vir regulon expression in agrobacterium tumefaciens involves both chromosome- and ti-plasmid-encoded gene products. we have isolated and characterized a new chromosomal gene that when mutated results in a 2- to 10-fold reduction in the induced expression of vir genes by acetosyringone. this reduced expression occurs in ab minimal medium (ph 5.5) containing either sucrose or glucose and containing phosphate at high or low concentrations. the locus was cloned and used to complement a. tumefaciens ... | 1992 | 1735704 |
| a self-transmissible, narrow-host-range endogenous plasmid of rhodobacter sphaeroides 2.4.1: physical structure, incompatibility determinants, origin of replication, and transfer functions. | rhodobacter sphaeroides 2.4.1 naturally harbors five cryptic endogenous plasmids (c. s. fornari, m. watkins, and s. kaplan, plasmid 11:39-47, 1984). the smallest plasmid (prs241e), with a molecular size of 42 kb, was observed to be a self-transmissible plasmid which can transfer only to certain strains of r. sphaeroides. transfer frequencies can be as high as 10(-2) to 10(-3) per donor under optimal mating conditions in liquid media in the absence of oxygen. prs241e, designated the s factor, was ... | 1992 | 1735707 |
| the agrobacterium tumefaciens vir gene transcriptional activator virg is transcriptionally induced by acid ph and other stress stimuli. | a set of agrobacterium tumefaciens operons required for pathogenesis is coordinately induced during plant infection by the vira and virg proteins. the intracellular concentration of virg increases in response to acidic media, and this response was proposed to be regulated at the level of transcription at a promoter (p2) that resembles the escherichia coli heat shock promoters. to test this hypothesis, we first constructed a virg-lacz transcriptional fusion. a strain containing this fusion had hi ... | 1992 | 1735712 |
| characterization of the supervirulent virg gene of the agrobacterium tumefaciens plasmid ptibo542. | the virg gene of the agrobacterium tumefaciens ti plasmid ptibo542 has previously been reported to elicit stronger vir gene expression than its counterpart in the ptia6 plasmid, a property we call the "superactivator" phenotype. the dna sequence of the ptibo542 virg gene was determined and compared to that of the ptia6 gene. the dna sequences of these genes differ at 16 positions: two differences are in the promoter regions, 12 are in the coding regions, and two are in the 3' untranslated region ... | 1991 | 1745238 |
| swimming against the tide: chemotaxis in agrobacterium. | chemotaxis in bacteria is an excellent model for signal transduction processes. in agrobacterium tumefaciens, the causative agent of crown gall tumour on wounded plants, it is a vital part of the organism's biology. a chromosomally-determined chemotaxis system causes the bacterium to be attracted into the rhizosphere by chemoattractants in plant exudates. by interfacing with this system, the multifunctional products of two ti-plasmid encoded genes, vira and virg, allow the sensing of specific wo ... | 1991 | 1772407 |
| an agrobacterium two-component regulatory system for the detection of chemicals released from plant wounds. | crown gall tumorigenesis by agrobacterium tumefaciens requires the co-ordinate transcriptional induction of a set of pathogenesis genes. at least three classes of environmental stimuli act synergistically to induce these genes: (i) monocyclic aromatic hydrocarbons such as acetosyringone, coniferyl alcohol, and vanillin, (ii) neutral or acidic monosaccharides such as glucose and glucuronic acid, and (iii) acidic ph. three proteins are required to sense and respond to these stimuli: (i) vira, a tr ... | 1991 | 1791750 |
| positive regulators of opine-inducible promoters in the nopaline and octopine catabolism regions of ti plasmids. | the noc and occ regions of nopaline and octopine ti plasmids in agrobacterium tumefaciens contain genes for the catabolism of nopaline and octopine, respectively. we investigated the transcriptional organization and regulation of both regions. the noc region of ptic58 contains two nopaline-inducible promoters, and one octopine-inducible promoter was identified in the occ region of ptiach5. all three promoters are positively regulated in trans by constitutively expressed genes localized at the ri ... | 1991 | 1799698 |
| transcription of the octopine catabolism operon of the agrobacterium tumor-inducing plasmid ptia6 is activated by a lysr-type regulatory protein. | agrobacterium tumefaciens incites crown gall tumors on plant hosts by conjugally transferring a discrete fragment of oncogenic dna. in addition to oncogenes, the transferred dna contains genes that direct the synthesis and exudation of opines, which are used as nutrients by the bacteria. the bacterium contains one or more operons of ti plasmid-encoded genes that are required for the internalization and utilization of opines, and transcription of these catabolic genes is induced by cognate opines ... | 1991 | 1799699 |
| mutants of the agrobacterium tumefaciens vira gene exhibiting acetosyringone-independent expression of the vir regulon. | hydroxylamine-induced mutations in the vira gene of agrobacterium tumefaciens that do not require the plant phenolic-inducing compound acetosyringone for vir regulon induction were isolated. the isolation was based on the activation of both virb::lacz and vire::cat fusions by mutant vira loci in the absence of acetosyringone. three of these vira(ais) (acetosyringone-independent signaling) mutants were characterized. all three mutants expressed a virb::lacz fusion at high levels in the absence of ... | 1991 | 1799700 |
| expression of rhizobium galegae common nod clones in various backgrounds. | the cosmid clone prg30, carrying common nodulation genes of rhizobium galegae hambi 1174, and prg33, a subclone of prg30 that contains a 5.7-kb clai insert carrying noddabc were conjugated into various rhizobium nod- mutant strains and into a ti plasmid-cured agrobacterium tumefaciens. complementation and expression of the nodabc genes of r. galegae were studied by following microscopically the infection process and the nodulation on different test plants. the nodabc genes of r. galegae compleme ... | 1991 | 1804401 |
| identification of 3-deoxy-lyxo-2-heptulosaric acid in the core region of lipopolysaccharides from rhizobiaceae. | a 3-deoxy-2-heptulosaric acid (dha), very probably with the lyxo-configuration, was identified in the r-core region of lipopolysaccharides from nodulating strains of rhizobium leguminosarum, rhizobium meliloti and from all three biovars of the phytopathogenic agrobacterium tumefaciens. its structure could be deduced from the fragmentation pattern of the corresponding alditol acetates obtained after reduction of the 2-keto and the 1.7-carboxy groups by sodium borohydride or sodium borodeuteride. ... | 1991 | 1804765 |
| synergistic action of phenolic signal compounds and carbohydrates in the induction of virulence gene expression of agrobacterium tumefaciens. | virulence (vir) gene expression of agrobacterium tumefaciens is activated by plant phenolic compounds such as alpha-hydroxyacetosyringone (hoas), acetosyringone (as), methyl syringate, coniferyl alcohol and sinapyl alcohol. inositol was found to be a potentiating factor of vir-inducing activity, which enhanced the vir-inducing activity of as and hoas in a synergistic manner, in particular at a low concentrations of as and hoas. of the other sugars tested d-glucose, l-rhamnose, d-xylose and d-gal ... | 1991 | 1806280 |
| characterization of an agrobacterium tumefaciens lectin. | an agrobacterium tumefaciens suspension induces a strong agglutination of aldehyde-fixed pig erythrocytes at ph 5.0. the agglutination is inhibited by some polysaccharides, such as fucoidin, and also when the ph is raised to 7.0. lectins (sugar-binding proteins) associated with the bacterial cell wall of a. tumefaciens strain 84.5 were directly evidenced by spectrofluorimetry using fluoresceinylated neoglycoproteins. the specific binding of the fluorescein-labelled neoglycoprotein bearing alpha- ... | 1991 | 1822244 |
| the osa gene of psa encodes a 21.1-kilodalton protein that suppresses agrobacterium tumefaciens oncogenicity. | the incompatibility group w plasmid psa suppresses agrobacterium tumefaciens oncogenicity (j. loper and c. kado, j. bacteriol. 139:591-596, 1979). the oncogenic suppressive activity was localized to a 3.1-kb region of psa by tn5 mutagenesis and deletion analysis. within this fragment, a 1.1-kb subclone bearing oncogenic suppressive activity was subjected to further characterization. nucleotide sequencing of the 1.1-kb fragment revealed a 570-bp open reading frame (orf1) that has a coding capacit ... | 1991 | 1832152 |
| tomato yellow leaf curl virus from sardinia is a whitefly-transmitted monopartite geminivirus. | the genome of an isolate of tomato yellow leaf curl virus from sardinia, italy (tylcv-s), a geminivirus transmitted by the whitefly bemisia tabaci, has been cloned and sequenced. the single circular dna molecule comprises 2770 nucleotides. genome organisation closely resembles that of the dna a component of the whitefly-transmitted geminiviruses with a bipartite genome. a 1.8 mer of the tylcv-s genome in a binary vector of agrobacterium tumefaciens is infectious upon agroinoculation of tomato pl ... | 1991 | 1840676 |
| phytochrome control of the tms2 gene in transgenic arabidopsis: a strategy for selecting mutants in the signal transduction pathway. | introduction of the tms2 gene from agrobacterium tumefaciens into arabidopsis thaliana yields transgenic seedlings with a new selectable phenotype: the seedlings are strongly growth inhibited on micromolar concentrations of auxin amide substrates that do not significantly affect wild-type seedlings. the tms2 gene encodes an amidohydrolase that catalyzes the conversion of biologically inactive auxin amides into active auxins, which are toxic to plants at elevated concentrations. in the absence of ... | 1991 | 1841718 |
| characterization of three agrobacterium tumefaciens avirulent mutants with chromosomal mutations that affect induction of vir genes. | three agrobacterium tumefaciens mutants with chromosomal mutations that affect bacterial virulence were isolated by transposon mutagenesis. two of the mutants were avirulent on all hosts tested. the third mutant, ivr-211, was a host range mutant which was avirulent on bryophyllum diagremontiana, nicotiana tabacum, n. debneyi, n. glauca, and daucus carota but was virulent on zinnia elegans and lycopersicon esculentum (tomato). that the mutant phenotype was due to the transposon insertion was dete ... | 1991 | 1846853 |
| direct evidence of the entner-doudoroff pathway operating in the metabolism of d-glucosamine in bacteria. | pseudomonas fluorescens (migula) (ifo 14808) has both a membrane-bound pqq-dependent d-glucose (d-glc) dehydrogenase [ec 1.1.99.17] [which also acts on d-glucosamine (d-glcn)] and a plp-dependent d-glucosaminate (d-glcna) dehydratase [ec 4.2.1.26]. further, these two enzymes were induced when d-glcn was added to the culture medium. however, d-glucosamine-6-phosphate (d-glcn-6-p) isomerase [ec 5.3.1.10], another enzyme involved in the metabolism of d-glcn, was only present at a low level in this ... | 1991 | 1849886 |
| organization of the agropine synthesis region of the t-dna of the ri plasmid from agrobacterium rhizogenes. | the agropine/mannopine synthesis region of the tr region of the ri plasmid of agrobacterium rhizogenes strain a4 was localized on the basis of sequence similarity with probes from ti plasmids of agrobacterium tumefaciens and analysis of transposon insertions. the nucleotide sequence of the right part of the tr-dna of pria4, encompassing the three genes involved in mannityl-opine synthesis, was determined and compared to the sequence of the corresponding region of the octopine-type ti plasmid pti ... | 1991 | 1852015 |
| 35s-beta-glucuronidase gene blocks biological effects of cotransferred iaa genes. | the iaam and iaah genes of agrobacterium tumefaciens and agrobacterium rhizogenes play an important role in crown gall and hairy root disease. the iaam gene codes for tryptophan monooxygenase which converts tryptophan into indole-3-acetamide (iam). iam is converted into the auxin indole-3-acetic acid (iaa) by indoleacetamide hydrolase, encoded by the iaah gene. in functional studies on the activity of the iaa genes of the tb region of the a. tumefaciens biotype iii strain tm4, the frequently use ... | 1991 | 1859868 |
| genetic and molecular analyses of pica, a plant-inducible locus on the agrobacterium tumefaciens chromosome. | pica is an agrobacterium tumefaciens chromosomal locus, identified by mu d11681 mutagenesis, that is inducible by certain acidic polysaccharides found in carrot root extract. cloning and genetic analysis of a pica::lacz fusion defined a region of the pica promoter that is responsible for the induction of this locus. furthermore, we identified a possible negative regulator of pica expression upstream of the pica locus. this sequence, denoted pgl, has extensive homology to polygalacturonase genes ... | 1991 | 1860822 |
| electrophoretic separation of the three rhizobium meliloti replicons. | the megaplasmids and the chromosome from the bacterium rhizobium meliloti 1021 were separated in preparative quantities by using transverse alternating-field gel electrophoresis. the genetic content of each electrophoretically separated band was determined by southern hybridization with replicon-specific probes and by comparison with agrobacterium tumefaciens transconjugants harboring either psym-a or psym-b megaplasmids. pulsed-field gel electrophoresis analyses of paci (5'-ttaattaa-3') and swa ... | 1991 | 1860826 |
| sequence of the iaa and ipt region of different agrobacterium tumefaciens biotype iii octopine strains: reconstruction of octopine ti plasmid evolution. | the ta regions of biotype iii octopine/cucumopine (oc) ti plasmids are closely related to the tl region of the biotype i octopine ti plasmids ptiach5 and pti15955. sequence analysis shows that the limited and wide host range biotype iii oc ta regions are derived from a common ancestor structure which lacked the 6a gene found in the biotype i octopine tl region. the ta region of the wide host range oc ti plasmids has conserved most of the original tl-like structure. in most wide host range oc iso ... | 1991 | 1868199 |
| sequence of agrobacterium tumefaciens biotype iii auxin genes. | 1991 | 1868204 | |
| production of beta-carotene in zymomonas mobilis and agrobacterium tumefaciens by introduction of the biosynthesis genes from erwinia uredovora. | the erwinia uredovora crtb, crte, crti, and crty genes required for beta-carotene biosynthesis were introduced by conjugal transfer into an ethanol-producing bacterium, zymomonas mobilis, and a phytopathogenic bacterium, agrobacterium tumefaciens, in which no carotenoid is synthesized. the transconjugants of z. mobilis and a. tumefaciens carrying these genes appeared as yellow colonies and produced 220 and 350 micrograms of beta-carotene per g of dry weight, respectively, in the stationary phase ... | 1991 | 1872613 |
| isolation of agrobacterium radiobacter from a central venous catheter. | a case of septicemia caused by agrobacterium radiobacter is reported in a patient undergoing chemotherapy treatment who had recently been neutropenic. agrobacterium radiobacter was isolated from the hickman line blood culture. the patient responded favorably to removal of the hickman catheter and treatment with amikacin and piperacillin. the molecular and biochemical characteristics of the isolate are presented. | 1991 | 1874251 |
| agrobacterium radiobacter peritonitis in two patients maintained on chronic peritoneal dialysis. | we report two patients with end-stage renal disease maintained on chronic peritoneal dialysis who developed peritonitis in which the infecting organism was agrobacterium radiobacter, normally a rare pathogen in humans. both patients initially responded to antibiotics, but later relapsed and required catheter removal. neither had been exposed to soil or plant material. a radiobacter is yet another of a growing list of unusual organisms that infect the peritoneal cavity of peritoneal dialysis pati ... | 1991 | 1882836 |
| expression of a bacterial lysine decarboxylase gene and transport of the protein into chloroplasts of transgenic tobacco. | a possible approach for altering alkaloid biosynthesis in plants is the expression of genes encoding key enzymes of a pathway such as lysine decarboxylase (ldc) in transgenic plants. two strategies were followed here: one focused on expression of the gene in the cytoplasm, the other on subsequent targeting of the protein to the chloroplasts. the ldcgene from hafnia alvei was therefore (a) placed under the control of the 1' promoter of the bidirectional tr promoter from agrobacterium tumefaciens ... | 1991 | 1883998 |
| auxin-induced expression of the soybean gh3 promoter in transgenic tobacco plants. | the gene encoding the auxin-responsive gh3 mrna (g. hagen, a. kleinschmidt, tj. guilfoyle, planta 162: 147-153 (1984] from soybean was cloned, and its sequence and transcription initiation site were determined. the promoter of the gh3 gene has been fused to the open reading frame of the escherichia coli uida gene which encodes beta-glucuronidase (gus). this fusion gene was introduced into tobacco via agrobacterium tumefaciens-mediated transformation, and the expression of the gene was examined b ... | 1991 | 1884011 |
| stimulation of agrobacterium tumefaciens t-dna transfer by overdrive depends on a flanking sequence but not on helical position with respect to the border repeat. | t-dna transfer by agrobacterium tumefaciens depends on the right border repeat of the t-dna and is greatly stimulated by overdrive, an adjacent sequence. we report that the function of overdrive does not depend on helical position with respect to the border repeat. a synthetic 24-bp overdrive and a 12-bp region containing a fully conserved 8-bp core overdrive sequence stimulated virulence equally, but full function required additional bases to the left of the 24-bp sequence. | 1991 | 1885533 |
| broad-host-range properties of plasmid rk2: importance of overlapping genes encoding the plasmid replication initiation protein trfa. | the trfa gene, encoding the essential replication initiation protein of the broad-host-range plasmid rk2, possesses an in-frame overlapping arrangement. this results in the production of trfa proteins of 33 and 44 kda, respectively. utilizing deletion and site-specific mutagenesis to alter the trfa operon, we compared the replication of an rk2-origin plasmid in several distantly related gram-negative bacteria when supported by both trfa-44 and trfa-33, trfa-33 alone, or trfa-44/98l (a mutant for ... | 1991 | 1885553 |
| cytokinin content and tissue distribution in plants transformed by a reconstructed isopentenyl transferase gene. | the cytokinin gene, isopentenyl transferase (ipt), was placed under the control of a heat-inducible promoter from the drosophila melanogaster hsp70 gene and introduced into nicotiana plumbaginifolia by cocultivation with agrobacterium tumefaciens. transformants were analyzed for organ-specific expression, cytokinin levels and effects on plant development before and after the heat induction. the ipt gene transcripts were detected in leaves and stems but not roots of transgenic plants following a ... | 1991 | 1888890 |
| analysis of the 5' flanking region responsible for the endosperm-specific expression of a rice glutelin chimeric gene in transgenic tobacco. | the 5' upstream region of the rice storage protein type ii glutelin gene was examined for its regulatory function in transgenic tobacco. chimeric genes containing 5' flanking regions of the glutelin gene transcriptionally fused to the beta-glucuronidase (gus) reporter gene were introduced into the tobacco genome by agrobacterium tumefaciens-mediated gene transfer. the chimeric genes were expressed specifically in developing seeds, as opposed to leaves and stems, of the transgenic tobacco. histoc ... | 1991 | 1888896 |
| survival of agrobacterium radiobacter k84 on various carriers for crown gall control. | screening was performed on nine carriers to find an improved formulation for agrobacterium radiobacter k84 cells. the survival data showed that it is possible to preserve a. radiobacter cells on dry solid supports for a long time provided that the storage temperature is 4 degrees c and that the inoculation volume for 4 x 10(9) cfu g-1 is not less than 0.15 ml g of carrier-1. on the other hand, a substantial carrier water content was necessary for room temperature storage. many materials proved t ... | 1991 | 1892394 |
| mannopine and mannopinic acid as substrates for arthrobacter sp. strain mba209 and pseudomonas putida na513. | the characteristics of mannopine and mannopinic acid utilization by agrobacterium tumefaciens b6s3, arthrobacter sp. strain mba209, and pseudomonas putida na513 were studied. strain b6s3 utilized the four mannityl opines, mannopine, mannopinic acid, agropine, and agropinic acid. it also utilized several mannityl opine analogs, which were modified in either the sugar or the amino acid moiety. it utilized mannopine more rapidly after preincubation on mannopine, mannopinic acid, or glutamine than a ... | 1991 | 1902209 |
| mutants of agrobacterium tumefaciens with elevated vir gene expression. | expression of agrobacterium tumefaciens virulence (vir) genes requires vira, virg, and a plant-derived inducing compound such as acetosyringone. to identify the critical functional domains of vira and virg, a mutational approach was used. agrobacterium a136 harboring plasmid pgp159, which contains vira, virg, and a reporter virb:lacz gene fusion, was mutagenized with uv light or nitrosoguanidine. survivors that formed blue colonies on a plate containing 5-bromo-4-chloro-3-indolyl beta-d-galactos ... | 1991 | 1908084 |
| mechanism of phenolic activation of agrobacterium virulence genes: development of a specific inhibitor of bacterial sensor/response systems. | the aglycone of the dihydrodiconiferyl alcohol glycosides, a series of phenolic growth factors able to substitute for some of the hormone requirements of tobacco cell division, are also potent inducers of virulence gene expression in agrobacterium tumefaciens. however, these factors do not conform to the previously established structural requirements necessary for vir expression. systematic evaluation of the structural requirements of these inducers has led to a model detailing the role of the p ... | 1991 | 1909032 |
| localization and orientation of the vird4 protein of agrobacterium tumefaciens in the cell membrane. | the vird4 gene of agrobacterium tumefaciens is essential for the formation of crown galls. analysis of the nucleotide sequence of vird4 has suggested that the n-terminal region of the encoded protein acts as a signal peptide for the transport of the vird4 protein to the cell membrane of agrobacterium. we have examined the localization and orientation of this protein in the cell membrane. when the nucleotides encoding the first 30 to 41 amino acids from the n-terminus of the vird4 protein were fu ... | 1991 | 1909421 |
| expression of a chimaeric granule-bound starch synthase-gus gene in transgenic potato plants. | granule-bound starch synthase is the key enzyme in amylose synthesis. the regulation of this gene was investigated using a chimaeric gene consisting of a 0.8 kb 5' upstream sequence of the granule-bound starch synthase gene from potato and the beta-glucuronidase gene which was introduced into potato using an agrobacterium tumefaciens binary vector system. the chimaeric gene was highly expressed in stolons and tubers, whereas the expression in leaves, stems or roots from greenhouse-grown plants w ... | 1991 | 1912493 |
| expression of a brassica napus extensin gene in the vascular system of transgenic tobacco and rape plants. | the organs and tissues where the brassica napus exta extensin gene is expressed have been identified. the exta gene with 3.75 kb of 5' flanking sequence was transferred to tobacco via disarmed agrobacterium tumefaciens vectors and transgenic plants regenerated. the gene was found to be inactive in transgenic tobacco leaf, but was active as measured by rna transcript assays in both stem and root tissues. to determine the cell-specific expression pattern of the exta gene, a promoter-reporter gene ... | 1991 | 1912494 |
| regulation of agrobacterium tumefaciens t-cyt gene expression in leaves of transgenic potato (solanum tuberosum l. cv. désirée) is strongly influenced by plant culture conditions. | the promoter region of the agrobacterium tumefaciens t-cyt gene was linked in a translational fusion to the coding dna of the reporter gene uida (for beta-glucuronidase or gus protein; ec 3.2.1.31) and to nos 3' flanking dna. the chimaeric gene was introduced by agrobacterium transformation into potato (solanum tuberosum l. cv. désirée). in nine transgenic lines, the average gus levels were highest in extracts from stems and roots of in vitro grown plants (ca. 11,000 gus activity units per pmol ... | 1991 | 1912495 |
| mismatch-specific dna breakdown in nuclear extract from tobacco (nicotiana tabacum) callus. | mismatch-specific enzymatic activity was sought for in nuclei from normal and transformed plant cells originating from tobacco (nicotiana tabacum) callus and crown gall tumor induced by agrobacterium tumefaciens. the specific enzymatic activity was assayed with substrates derived from synthetic oligonucleotides (19-mer sequences corresponding to the human k-ras gene). single-base changes in the middle of the sequence were the basis for creating heteroduplexes with all eight mismatches. homo- and ... | 1991 | 1912502 |
| the nucleotide sequence and genome structure of the geminivirus miscanthus streak virus. | a tandem dimer of miscanthus streak virus (misv) dna was inserted into the t-dna of the binary plasmid vector pbin19 and agroinoculated into several monocotyledonous plants (monocots) using agrobacterium tumefaciens or a. rhizogenes. disease symptoms and geminate particles were produced in maize and panicum milaceum plants, and misv-specific double-stranded and single-stranded dnas were found in these plants. the nucleotide sequence of the infectious misv clone, consisting of 2672 nucleotides, w ... | 1991 | 1919519 |
| role of t-region borders in agrobacterium host range. | the limited host range ab3 strain of agrobacterium tumefaciens induces tumors by transferring two t-regions, ta and tb. ta is a deleted version of the well-known biotype i octopine tl-region that lacks the iaa and ipt genes, but carries an intact oncogene, gene 6b, and typical left and right border sequences. tb carries two iaa genes that together code for the synthesis of indoleacetic acid. gene 6b and the iaa gene act synergistically when transferred in a coinoculation experiment. the ta-regio ... | 1991 | 1932812 |
| a semiquantitative bioassay for relative virulence of agrobacterium tumefaciens strains on bryophyllum daigremontiana. | an assay to determine the relative virulence of wild-type and mutant strains of agrobacterium tumefaciens on leaves of bryophyllum daigremontiana has been developed. this assay is reproducible, is easy to learn, is not time consuming, and requires little space. the relative virulence of cellulose-minus mutants of a. tumefaciens was investigated with this assay. some of these mutants were unaltered in virulence, while others showed a marked reduction in virulence. | 1991 | 1938971 |
| induction of the alka gene of escherichia coli in gram-negative bacteria. | a broad-host-range plasmid containing a fusion of the alka and lacz genes of escherichia coli was introduced into various aerobic and facultative gram-negative bacteria--33 species belonging to 19 genera--to study the induction of expression of the alka gene by alkylating agents. the bacteria included species of the families enterobacteriaceae, pseudomonadaceae, rhizobiaceae, vibrionaceae, neisseriaceae, rhodospirillaceae, and azotobacteraceae. results obtained show that all bacteria tested, exc ... | 1991 | 1938974 |
| structural characterization of protein secretion genes of the bacterial phytopathogen xanthomonas campestris pathovar campestris: relatedness to secretion systems of other gram-negative bacteria. | the nucleotide sequence was determined of a 5.3 kb region of the xanthomonas campestris pathovar campestris genome carrying a gene cluster encoding protein secretion and pathogenicity functions. a putative promoter sequence and five open reading frames (orf) which may be part of an operon were revealed. the five predicted primary translation products comprise 531, 390, 147, 169 and 138 amino acids with mr values of 58,854, 42,299, 15,548, 18,214 and 15,108 respectively. a sixth, partial orf is a ... | 1991 | 1944223 |
| repression of the camv 35s promoter by the octopine synthase enhancer element. | a 16 base-pair palindrome upstream of the agrobacterium tumefaciens octopine synthase (ocs) gene functions as a positive regulatory element in plant cells (ellis et al. (1987) embo j. 6, 3203-3208; fromm et al. (1989) plant cell 1, 977-984). we have converted it into a negative element by locating two copies flanking the tata-box of the constitutively expressed camv 35s promoter. the reduced promoter activity is very likely due to sterical hindrance of the ocs binding protein (ocstf) x ocs compl ... | 1991 | 1959656 |
| nucleotide sequence analysis of is427 and its target sites in agrobacterium tumefaciens t37. | we have determined the nucleotide sequence of is427, an insertion sequence from agrobacterium tumefaciens t37, is427 is 1271 bp long, contains 16-bp imperfect terminal inverted repeats, and generates a 2-bp target sequence duplication. it is present at three sites in the ptit37 plasmid and is absent from the chromosome of a. tumefaciens t37. each of the is427 elements sequenced was near a site with sequence homology to integration host factor (ihf)-binding sites which suggested that ihf may be i ... | 1990 | 1963949 |
| [design of an expression integrative vector and its application for introducing the human recombinant alfa interferon gene into plants]. | integrative expression vector pst6 was developed for dicote plant transformation. the vector contains neomycin phosphotransferase gene under control of pnos promoter which confers kanamycin resistance to transformed plant cells. the vector also includes expression cassette with strong constitutive 35s camv promoter for cloning of foreign genes. the human recombinant alfa interferon gene has been inserted into the expression cassette of pst6. recombinant plasmid obtained was transferred into agro ... | 1990 | 1964923 |
| improved binary vectors for agrobacterium-mediated plant transformation. | improved plant transformation vectors were constructed which utilize the prihri origin of replication for highly stable maintenance in agrobacterium tumefaciens, the cole1 origin of replication for high copy maintenance in escherichia coli, and a gentamycin resistance gene as a strong selectable marker for bacteria. concise t-dna elements were engineered with border sequences from the tl-dna of ptia6, the tn5 neomycin phosphotransferase gene (npt ii) expressed from either camv 35s or mannopine s ... | 1990 | 1966276 |
| agrobacterium-mediated dna transfer in sugar pine. | dna transfer using agrobacterium tumefaciens has been demonstrated in sugar pine, pinus lambertiana dougl. shoots derived from cytokinin-treated cotyledons formed galls after inoculation with a. tumefaciens strains containing the plasmid ptibo542. a selectable marker, neomycin phosphotransferase ii, conferring resistance to kanamycin, was transferred into sugar pine using a binary armed vector system. callus proliferated from the galls grew without hormones and in some cases, kanamycin-resistant ... | 1990 | 1966486 |
| a previously unrecognized glutamine synthetase expressed in klebsiella pneumoniae from the glnt locus of rhizobium leguminosarum. | using glnt dna of rhizobium meliloti as a hybridization probe we identified a r. leguminosarum biovar phaseoli (r. l. phaseoli) locus (glnt) expressing a glutamine synthetase activity in klebsiella pneumoniae. a 2.2 kb dna fragment from r. l. phaseoli was cloned to give plasmid pmw5a, which shows interspecific complementation of a k. pneumoniae glna mutant. the cloned sequence did not show cross-hybridization to glna or glnii, the genes coding for two glutamine synthetase isozymes of rhizobium s ... | 1990 | 1980142 |
| transport of nonmetabolizable opines by agrobacterium tumefaciens. | we have examined the uptake of [14c]octopine and [14c]nopaline by agrobacterium tumefaciens strains containing the c58 chromosomal background in medium suitable for the induction of vir genes. all strains tested could transport both of these opines, regardless of the presence or type of ti plasmid (octopine or nopaline) present in the bacterium. the transport of these opines required active cellular metabolism. nonradioactive octopine, nopaline, and arginine competed effectively with [14c]octopi ... | 1991 | 1987170 |
| controlled expression of the transcriptional activator gene virg in agrobacterium tumefaciens by using the escherichia coli lac promoter. | the agrobacterium virg protein is normally expressed from two promoters in response to multiple stimuli, including plant-released phenolics (at promoter p1) and acidic growth media (at promoter p2). to simplify the analysis of vir gene induction, we sought to create agrobacterium strains in which virg could be expressed in a controllable fashion. to study the possibility of using the lac promoter and repressor, we constructed a plasmid containing the lac promoter fused to the lacz structural gen ... | 1991 | 1991713 |
| illegitimate recombination in plants: a model for t-dna integration. | agrobacterium tumefaciens is a soil bacterium capable of transferring dna (the t-dna) to the genome of higher plants, where it is then stably integrated. six t-dna inserts and their corresponding preinsertion sites were cloned from arabidopsis thaliana and analyzed. two t-dna integration events from nicotiana tabacum were included in the analysis. nucleotide sequence comparison of plant target sites before and after t-dna integration showed that the t-dna usually causes only a small (13-28 bp) d ... | 1991 | 1995418 |
| sequence identity in the nick regions of incp plasmid transfer origins and t-dna borders of agrobacterium ti plasmids. | the incp antibiotic-resistance plasmids transfer to a broad range of bacterial species. the rk2 origin of dna transfer (orit) consists of a 250-base-pair segment including the single-stranded cleavage site (nic) needed to generate the dna strand believed to be transferred. deletion derivatives and a bank of hydroxylamine-generated orit mutants were screened for loss of transferability. dna regions flanking both sides of nic are required for optimal transfer of the orit clone. of the chemically i ... | 1991 | 1996345 |
| cloning and characterization of an amidase gene from rhodococcus species n-774 and its expression in escherichia coli. | for investigation of an unknown open reading frame which is present upstream of the nitrile hydratase (nhase) gene from rhodococcus sp. n-774, a longer dna fragment covering the entire gene was cloned in escherichia coli. nucleotide sequencing and detailed subcloning experiments predicted a single open reading frame consisting of 521 amino acid residues of mr 54,671. the amino acid sequence, especially its nh2-terminal portion, showed significant homology with those of indoleacetamide hydrolases ... | 1991 | 2001397 |
| a diffusible compound can enhance conjugal transfer of the ti plasmid in agrobacterium tumefaciens. | several octopine strains of agrobacterium tumefaciens were tested for ti plasmid (pti) transfer after induction by 400 micrograms of octopine per ml for 24 h. the strains could be divided into two groups, transfer efficient (trae) and transfer inefficient (traie); the respective rates of transfer were 0.77 x 10(-2) to 1.14 x 10(-2) and 0.33 x 10(-6) to 9.8 x 10(-6) plasmid transconjugant per donor cell. transfer efficiencies of traie strains were greatly increased when the time of induction was ... | 1991 | 2001991 |
| nucleotide sequence analysis of a chloramphenicol-resistance determinant from agrobacterium tumefaciens and identification of its gene product. | the nucleotide sequence of a chloramphenicol-resistance (cmr) determinant from the gram- soil bacterium agrobacterium tumefaciens was determined, and its gene product was identified as cm acetyltransferase (cat). comparison of the amino acid sequences of the a. tumefaciens cat and various cat proteins of gram+ and gram- origin shows no homology between this and the other enzymes. | 1991 | 2013403 |
| the virc and vird operons of the agrobacterium ti plasmid are regulated by the ros chromosomal gene: analysis of the cloned ros gene. | the ros chromosomal gene is present in octopine and nopaline strains of agrobacterium tumefaciens as well as in rhizobium meliloti. this gene encodes a 15.5-kda protein that specifically represses the virc and vird operons in the virulence region of the ti plasmid. the ros gene was cloned from a genomic bank by electroporation and complementation in agrobacterium cells. reporter fusion to the ros gene indicates that the level of transcription is controlled in part by autoregulation. a consensus ... | 1991 | 2013576 |
| studies on heterologous expression of rhizobium meliloti nifa gene and oxygen sensitivity of its product. | when the r. meliloti (rm) nifa'-lacz fusion-carrying plasmids were introduced into the strains of agrobacterium tumefaciens, r. trifolii and r. astragalus, beta-galactosidase activity was demonstrated. however, activity was not induced by microaerobiosis. furthermore, r. meliloti nifa'-lacz fusion was also not expressed in the nodule bacteroids of r. trifolii and r. astragalus. we speculate that some factor(s) important for the induction of rm nifa presumed to be the fixlj regulatory system woul ... | 1991 | 2015065 |
| cloning and nucleotide sequence of the hema gene of agrobacterium radiobacter. | the hema gene of agrobacterium radiobacter atcc4718 was identified by hybridization with a hema probe from rhizobium meliloti and cloned by complementation of a hema mutant of escherichia coli k12. e. coli hema transformants carrying the hema gene of agrobacterium showed delta-aminolevulinic acid synthetase (delta-alas) activity in vitro. the hema gene was carried on a 4.4 kb ecori fragment which could be reduced to a 2.6 kb ecori-ssti fragment without affecting its complementing or delta-alas a ... | 1991 | 2034217 |
| viable but nonculturable bacteria in drinking water. | klebsiella pneumoniae, enterobacter aerogenes, agrobacterium tumefaciens, streptococcus faecalis, micrococcus flavus, bacillus subtilis, and pseudomonas strains l2 and 719 were tested for the ability to grow and maintain viability in drinking water. microcosms were employed in the study to monitor growth and survival by plate counts, acridine orange direct counts (aodc), and direct viable counts (dvc). plate counts dropped below the detection limit within 7 days for all strains except those of b ... | 1991 | 2039237 |
| agrobacterium radiobacter bacteremia in a child with human immunodeficiency virus infection. | 1991 | 2062633 | |
| specific binding of virg to the vir box requires a c-terminal domain and exhibits a minimum concentration threshold. | the positive regulatory protein virg from the virulence region of the ti plasmid of agrobacterium tumefaciens was first demonstrated to possess dna-binding capabilities using chromatographically purified protein and in vitro assays (powell et al., 1989). this paper is an extension of that research and presents evidence on the in vivo dna-binding properties of virg using a transcription interference assay. virg protein bound specifically to a 'vir box' response element and repressed transcription ... | 1990 | 2089226 |
| expression of a rice glutelin promoter in transgenic tobacco. | a chimeric gene consisting of the 5' flanking sequences of a rice glutelin gene (gt3) linked to the chloramphenicol acetyltransferase (cat) coding segment was introduced into tobacco via agrobacterium tumefaciens-mediated transformation. cat enzyme activity could be detected in extracts from seeds as early as 8 days after flowering and obtained a maximum level at 16 days after flowering, the onset of overall protein accumulation. significant expression of cat activity in non-seed tissues occurre ... | 1990 | 2101310 |
| localized transient expression of gus in leaf discs following cocultivation with agrobacterium. | a chimaeric gene has been constructed that expresses beta-d-glucuronidase (gus) in transformed plant tissues, but not in bacterial cells. this gene has proved extremely useful for monitoring transformation during the period immediately following gene transfer from agrobacterium tumefaciens. gus expression was detectable 2 days after inoculation, peaked at 3-4 days and then declined; if selection was imposed expression increased again after 10-14 days. the extent of transient expression after 4 d ... | 1990 | 2101312 |
| t-dna presence and opine production in tumors of picea abies (l.) karst induced by agrobacterium tumefaciens a281. | the hypervirulent agrobacterium tumefaciens strain a281 formed frequent tumors (31%) on picea abies (norway spruce), an economically important tree species in swedish forests. three-month-old seedlings were inoculated and tumors were established that grew hormone-independently in culture. tumors contained agropine and mannopine/mannopinic acid as determined by acid ph paper electrophoresis. in addition, dna hybridization studies showed that the dna from these tumor lines contained sequences homo ... | 1990 | 2101685 |
| functional analysis of a complex oncogene arrangement in biotype iii agrobacterium tumefaciens strains. | the ubiquitous grapevine-associated octopine/cucumopine ti plasmids of biotype iii agrobacterium tumefaciens strains carry two t regions, ta and tb, with a complex oncogene arrangement. within the octopine/cucumopine group, two main strain types were identified: 'large ta' strains with a ta region resembling the tl region of the biotype i octopine strain ach5 and 'small ta' strains with a similar t region organization as the 'large ta' strains but with a large internal ta deletion. structural an ... | 1990 | 2101690 |
| octopine and nopaline strains of agrobacterium tumefaciens differ in virulence; molecular characterization of the virf locus. | octopine and nopaline strains of agrobacterium tumefaciens were found to differ in virulence on nicotiana glauca. this difference is due to the absence of a functional virf locus, which is necessary for efficient tumorigenesis on n. glauca, from the nopaline ti plasmids. genetic studies and dna sequence analysis of the virf locus revealed that virf embraces one open reading frame coding for a hydrophilic protein with a molecular mass of 22,437 da. transcription of virf is directed from left to r ... | 1990 | 2101693 |
| characteristics of a strong promoter from figwort mosaic virus: comparison with the analogous 35s promoter from cauliflower mosaic virus and the regulated mannopine synthase promoter. | a segment of dna from the genome of figwort mosaic virus (fmv) strain m3 possesses promoter activity when tested in electroporated protoplasts from, and transgenic plants of, nicotiana tabacum cv. xanthi nc. the 1.1 kb dna segment, designated the '34s' promoter, is derived from a position on the fmv genome comparable to the position on the cauliflower mosaic virus (camv) genome containing the 35s promoter. the 34s and 35s promoters show approximately 63% nucleotide homology in the tata, ccact, a ... | 1990 | 2102823 |
| transformation and regeneration of the self-incompatible species nicotiana alata link & otto. | a transformation and regeneration system has been developed for nicotiana alata, a plant which is being intensively studied as a model of gametophytic self-incompatibility. plantlets can be regenerated efficiently from seedling hypocotyls. kanamycin-resistant, transformed plants have been obtained by cocultivation of regenerating hypocotyls with agrobacterium tumefaciens strain lba4404 containing a binary vector. the transformation frequency was low with less than 1% of tissue explants regenerat ... | 1990 | 2102859 |
| [demonstration of 3 functional domains responsible for a kinase activity in vira, a transmembrane sensory protein encoded by the ti plasmid of agrobacterium tumefaciens]. | high-level expression of chimeric vira genes were obtained by replacing the first codons of vira with the first codons of trpe. the fusion proteins encoded by these constructs were partially purified and one of them exhibited autokinase activity. therefore, protein phosphorylation may be an important feature of vira function. this allowed us to define the existence of three functional domains inside vira. | 1990 | 2105145 |
| stereospecific abstraction of epsilon-pro-r-hydrogen of l-lysine by l-lysine epsilon-dehydrogenase from agrobacterium tumefaciens. | the stereochemical aspects of the l-lysine epsilon-dehydrogenase reaction were examined with (6r)-l-[6-3h]lysine and (6s)-dl-[6-3h]lysine. when (6s)-dl-[6-3h]lysine was used as a substrate, the tritium was found in the product, delta 1-piperideine-6-carboxylate. in contrast, the radioactivity from (6r)-l-[6-3h]lysine was not retained in the product. thus, the pro-r hydrogen at the prochiral c-6 carbon of l-lysine is specifically abstracted by the enzyme: the enzyme behaves stereochemically as an ... | 1990 | 2110154 |
| identification of an agrobacterium tumefaciens virulence gene inducer from the pinaceous gymnosperm pseudotsuga menziesii. | inducible t-strand mobilization from the ti plasmid of agrobacterium tumefaciens to the genome of a plant host is mediated by the activation of a cascade of bacterial virulence genes. it is initiated when the bacterium senses the presence of a low molecular weight inducer secreted by the plant. although many hydroxyphenylpropanoid and phenolic compounds can activate the virulence cascade, the only native inducers that have been identified to date are acetosyringone and hydroxyacetosyringone. a n ... | 1990 | 2110367 |
| sugars induce the agrobacterium virulence genes through a periplasmic binding protein and a transmembrane signal protein. | phenolic plant metabolites such as acetosyringone induce transcription of the virulence (vir) genes of agrobacterium tumefaciens through the transmembrane vira protein. we report here that certain sugars induce the vir genes synergistically with phenolic inducers by way of a distinct regulatory pathway that includes vira and a chromosomally encoded virulence protein, chve. sequence comparison showed that chve is a periplasmic galactose-binding protein corresponding to the gbp1 protein isolated f ... | 1990 | 2118656 |
| sugar-mediated induction of agrobacterium tumefaciens virulence genes: structural specificity and activities of monosaccharides. | the virulence genes of agrobacterium tumefaciens are induced by specific plant phenolic metabolites and sugars (g. a. cangelosi, r. g. ankenbauer, and e. w. nester, proc. natl. acad. sci. usa, in press). in this report, monosaccharides, derivatives, and analogs which induce the vir regulon have been identified and the structural requirements for monosaccharide-mediated induction have been determined. pyranose sugars with equatorial hydroxyls at c-1, c-2, and c-3 displayed strong vir gene-inducin ... | 1990 | 2121715 |