| the sixty nucleotide occr operator contains a subsite essential and sufficient for occr binding and a second subsite required for ligand-responsive dna bending. | occr is a transcriptional regulatory protein of agrobacterium tumefaciens that activates the occq operon in response to octopine, an arginine derivative released from plant tumors. occr binds to its operator with similar affinity and the same stoichiometry in the presence or absence of octopine, but octopine shortens the protein's dnase i footprint and partially relaxes an occr-incited dna bend. in this study, resections and other alterations of the operator were used to demonstrate that 19 nucl ... | 1995 | 7473744 |
| the bacterial 'enigma': cracking the code of cell-cell communication. | in recent years it has become clear that the production of n-acyl homoserine lactones (n-ahls) is widespread in gram-negative bacteria. these molecules act as diffusible chemical communication signals (bacterial pheromones) which regulate diverse physiological processes including bioluminescence, antibiotic production, plasmid conjugal transfer and synthesis of exoenzyme virulence factors in plant and animal pathogens. the paradigm for n-ahl production is in the bioluminescence (lux) phenotype o ... | 1995 | 7476157 |
| mutational analysis of a conserved motif of agrobacterium tumefaciens vird2. | the vird2 polypeptide from agrobacterium tumefaciens, in the presence of vird1, introduces a site- and strand-specific nick at the t-dna borders. a similar reaction at the origin of transfer (orit) of plasmids is essential for plasmid transfer by bacterial conjugation. a comparison of protein sequences of vird2 and its functional homologs in bacterial conjugation and in rolling circle replication revealed that they share a conserved 14 residue segment, hxdxxx(p/u)huhuuux [residues 126-139 of vir ... | 1995 | 7479069 |
| isolation and characterization of a novel insertion sequence element, is1248, in paracoccus denitrificans. | a new suicide vector, prvs3, was constructed to facilitate gene replacements in the genome of paracoccus denitrificans. in control experiments, incorporation of this suicide vector into the genome did not depend on the presence of homologous dna. using appropriate restriction enzymes, the suicide vector and flanking dna were recovered from the genomic dna. sequence analysis demonstrated that both up- and downstream of the ex-integrant vector there was an element that showed high homology with ba ... | 1995 | 7480167 |
| stress activation of a bean hydroxyproline-rich glycoprotein promoter is superimposed on a pattern of tissue-specific developmental expression. | the hrgp4.1 gene, which encodes a cell wall hydroxyproline-rich glycoprotein, was isolated from a genomic library of bean (phaseolus vulgaris l.). two transcripts, one induced by wounding and one by elicitation, were transcribed from the same initiation site. the gene encodes a polypeptide of 580 amino acids with the amino terminal half consisting of repeats of the sequence serine-(proline)4-lysine-histidine-serine-(proline)4-(tyrosine)3-histidi ne and the carboxyl-terminal half composed of repe ... | 1995 | 7480331 |
| universal pcr primers for detection of phytopathogenic agrobacterium strains. | two pcr primer pairs, based on the vird2 and ipt genes, detected a wide variety of pathogenic agrobacterium strains. the endonuclease domain of vird2 protein, which cleaves transferred dna (t-dna) border sequences, is highly conserved; primer oligonucleotides specific for the endonuclease portion of vird2 detected all pathogenic strains of agrobacterium tested. pcr primers corresponding to conserved sequences in ipt, the t-dna-borne cytokinin synthesis gene, detected only agrobacterium tumefacie ... | 1995 | 7487020 |
| properties of d-hydantoinase from agrobacterium tumefaciens and its use for the preparation of n-carbamyl d-amino acids. | agrobacterium tumefaciens strain 47c expresses an inducible d-hydantoinase that catalyzes the formation of optically pure n-carbamyl d-amino acids from racemic hydantoin precursors. the d-hydantoinase was shown to be active and stable at elevated temperatures and ph values, thus affording favorable bioreaction conditions that result in the racemization of dl-hydantoins to the utilizable d-isomer. the enzyme demonstrated optimal reaction kinetics at ph 10 and 70 degrees c, was not activated by me ... | 1995 | 7488185 |
| an agrobacterium virulence factor encoded by a ti plasmid gene or a chromosomal gene is required for t-dna transfer into plants. | mutagenesis of the vir region on the ti plasmid of agrobacterium tumefaciens revealed a new locus, virj, that is induced by the plant-wound signal molecule, acetosyringone (as). virj lies between vira and virb, and is transcribed in the same direction. the amino acid sequence of virj is similar to a region of a previously characterized chromosomal gene, acvb, required for virulence. virj can complement the avirulent phenotype of an acvb mutant, indicating that virj and acvb encode the same facto ... | 1995 | 7494475 |
| isolation and sequence analysis of rpoh genes encoding sigma 32 homologs from gram negative bacteria: conserved mrna and protein segments for heat shock regulation. | the rpoh genes encoding homologs of escherichia coli sigma 32 (heat shock sigma factor) were isolated and sequenced from five gram negative proteobacteria (gamma or alpha subgroup): enterobacter cloacae (gamma), serratia marcescens (gamma), proteus mirabilis (gamma), agrobacterium tumefaciens (alpha) and zymomonas mobilis (alpha). comparison of these and three known genes from e.coli (gamma), citrobacter freundii (gamma) and pseudomonas aeruginosa (gamma) revealed marked similarities that should ... | 1995 | 7501460 |
| agrobacterium-mediated inoculation of pstvd cdnas onto tomato reveals the biological effect of apparently lethal mutations. | potato spindle tuber viroid (pstvd) mutants which contain alterations in the terminal loops of the rod-like native structure have previously been reported from our laboratory. pstvd-p contains mutations at positions 2, 4, and 6 in the left terminal loop; pstvd-r+, a sequence permutation of pstvd-r, contains the same mutations at positions 177 and 178 in the right terminal loop as pstvd-r and contains in addition a 1-nucleotide g insertion at position 176. pstvd-p, pstvd-r, and pstv-r+ were nonin ... | 1994 | 7513926 |
| the groesl operon of agrobacterium tumefaciens: evidence for heat shock-dependent mrna cleavage. | the heat shock response of the groesl operon of agrobacterium tumefaciens was studied at the rna level. the operon was found to be activated under heat shock conditions and transcribed as a polycistronic mrna that contains the groes and groel genes. after activation, the polycistronic mrna appeared to be cleaved between the groes and groel genes and formed two monocistronic mrnas. the groes cleavage product appeared to be unstable and subjected to degradation, while the groel cleavage product ap ... | 1995 | 7530710 |
| field evaluation of transgenic potato plants expressing an antisense granule-bound starch synthase gene: increase of the antisense effect during tuber growth. | transgenic plants of a tetraploid potato cultivar were obtained in which the amylose content of tuber starch was reduced via antisense rna-mediated inhibition of the expression of the gene encoding granule-bound starch synthase (gbss). gbss is one of the key enzymes in the biosynthesis of starch and catalyses the formation of amylose. the antisense gbss genes, based on the full-length gbss cdna driven by the 35s camv promoter or the potato gbss promoter, were introduced into the potato genome by ... | 1994 | 7532028 |
| a phylogenetic analysis of micro-organisms isolated from subsurface environments. | three methods were used to provide information on the identity and phylogenetic relatedness of 19 aerobic, chemoheterotrophic bacteria isolated from topsoil and deep subsurface sediments at a site in south carolina. these methods were (i) analysis of selected physiological traits, (ii) restriction endonuclease analysis (rea) of genomic dna, and (iii) analysis of 16s ribosomal rna sequences. when the 16s rrna sequences were compared with those for 12 standard strains, two topsoil isolates and six ... | 1995 | 7536094 |
| the effect of ph and oxygen concentration on the formation of 3-ketodisaccharides by agrobacterium tumefaciens. | the further optimization of 3-ketodisaccharide formation with sucrose, leucrose and iso maltulose was studied with special regard to ph and oxygen concentration in the reaction mixture with resting cells of agrobacterium tumefaciens. it was found that the optimal ph values for the highest reaction rate and highest yield were different as the ph affected the stability of the 3-keto derivatives formed. a ph shift to 5.0 clearly reduced the enzymatic degradation of the 3-keto derivatives thus stabi ... | 1995 | 7546608 |
| highly insect-resistant transgenic tobacco plants containing both b.t. and cpti genes. | the cowpea trypsin inhibitor (cpti) gene was synthesized according to its cdna sequence using dna synthesizer and confirmed by dna sequencing. the cpti gene and modified bacillus thuringiensis (b.t.) delta-endotoxin gene were cotransformed to tobacco explants mediated by agrobacterium tumefaciens. the integrations of b.t and cpti genes were confirmed by pcr and southern hybridization. three kinds of transgenic plants were obtained: (1) containing cpti gene, (2) containing b.t gene, (3) containin ... | 1995 | 7548766 |
| transfer of non-t-dna portions of the agrobacterium tumefaciens ti plasmid ptia6 from the left terminus of tl-dna. | we introduced a plant selection marker, nptii, to the left of border a in the agrobacterium ti plasmid ptia6. infection of tobacco leaf discs with the modified agrobacterium strain gave rise to kanamycin-resistant calli which grew in a hormone-dependent manner. southern hybridization analysis of dna isolated from four transformants indicated initiation of dna transfer at or near border a and absence of t-dna sequences. these results demonstrate that dna transfer events starting at a left border ... | 1995 | 7548833 |
| cloning, sequencing, and phenotypic analysis of laf1, encoding the flagellin of the lateral flagella of azospirillum brasilense sp7. | azospirillum brasilense can display a single polar flagellum and several lateral flagella. the a. brasilense sp7 gene laf1, encoding the flagellin of the lateral flagella, was isolated and sequenced. the derived protein sequence is extensively similar to those of the flagellins of rhizobium meliloti, agrobacterium tumefaciens, bartonella bacilliformis, and caulobacter crescentus. an amino acid alignment shows that the flagellins of these bacteria are clustered and are clearly different from othe ... | 1995 | 7559324 |
| identification of rhizobium-specific intergenic mosaic elements within an essential two-component regulatory system of rhizobium species. | analysis of the dna regions upstream of the phosphoenolpyruvate carboxykinase gene (pcka) in rhizobium meliloti and rhizobium sp. strain ngr234 identified an open reading frame which was highly homologous to the agrobacterium tumefaciens chromosomal virulence gene product chvi. a second gene product, 500 bp downstream of the chvi-like gene in r. meliloti, was homologous to the a. tumefaciens chvg protein. the homology between the r. meliloti and a. tumefaciens genes was confirmed, because the r. ... | 1995 | 7559334 |
| [comparative susceptibility of ochrobactrum anthropi, agrobacterium tumefaciens, alcaligenes faecalis, alcaligenes denitrificans subsp. denitrificans, alcaligenes denitrificans subsp. xylosidans and bordetella bronchiseptica against 35 antibiotics including 17 beta-lactams]. | ochrobactrum anthropi, formerly known as "achromobacter sp." or cdc group vd has been isolated from water, hospital environment (antiseptic solutions, dialysis fluids ... ). o. anthropi is a gram negative, motile, strictly aerobic, oxydase positive and non-fermentative bacteria with a strong urease activity. the susceptibility of 13 strains of o. anthropi was determined by agar diffusion method and compared to those of type strains of agrobacterium tumefaciens, alcaligenes faecalis, alcaligenes ... | 1995 | 7567111 |
| expression vectors for the use of eukaryotic luciferases as bacterial markers with different colors of luminescence. | an easy way to identify microorganisms is to provide them with gene markers that confer a unique phenotype. several genetic constructions were developed to use eukaryotic luciferase genes for bacterial tagging. the firefly and click bettle luciferase genes, luc and lucor, respectively, were cloned under constitutive control and regulated control from different transcriptional units driven by p1, lambda pr, and ptrc promoters. comparison of the expression of each gene in escherichia coli cells fr ... | 1995 | 7574604 |
| rice scutellum induces agrobacterium tumefaciens vir genes and t-strand generation. | for successful transformation of a plant by agrobacterium tumefaciens it is essential that the explant used in cocultivation has the ability to induce agrobacterium tumour-inducing (ti) plasmid virulence (vir) genes. here we report a significant variation in different tissues of indica rice (oryza sativa l. cv. co43) in their ability to induce agrobacterium tumefaciens vir genes and t-strand generation, using explants preincubated in liquid murashige and skoog (ms) medium. an analysis of rice le ... | 1995 | 7579158 |
| site-directed mutagenesis of the enhancer region of the 780 gene promoter of t-dna. | potential regulatory sequences within the enhancer-like region of the 780 gene promoter (agrobacterium tumefaciens t-dna) were identified by site-directed mutagenesis. transcriptional activity of the mutated promoter was analyzed by s1 nuclease mapping of rna from crown gall tumors of sunflower incited using a t-dna-based vector. variability in expression levels were minimized by the use of an internal reference gene and the pooling of at least 200 tumors per construct tested. this approach iden ... | 1995 | 7579171 |
| a novel wound-inducible extensin gene is expressed early in newly isolated protoplasts of nicotiana sylvestris. | a cdna clone (6pext 1.2) encoding a novel extensin was isolated from a cdna library made from 6 h old mesophyll protoplasts of nicotiana sylvestris. the screening was performed with a heterologous probe from carrot. the encoded polypeptide showed features characteristic of hydroxyproline-rich glycoproteins such as ser-(pro)4 repeats and a high content in tyr and lys residues. the presence of four tyr-x-tyr-lys motifs suggests the possibility for intramolecular isodityrosine cross-links whereas t ... | 1995 | 7579179 |
| pleiotropic effects of regulatory ros mutants of agrobacterium radiobacter and their interaction with fe and glucose. | four exo mutants of agrobacterium radiobacter, defective in the synthesis of acidic exopolysaccharide were complemented by a gene from that species, which is similar to the transcriptional regulator, ros, of a. tumefaciens. it was confirmed that this a. radiobacter gene, which we term rosar, like ros, repressed its own transcription as well as that of virc and vird, two loci involved in tumorigenesis. the sequence of rosar suggested that it might bind to a transition metal and its repressor abil ... | 1995 | 7579618 |
| regulation of agrobacterium tumefaciens virulence gene expression: isolation of a mutation that restores virgd52e function. | expression of agrobacterium tumefaciens virulence (vir) genes is controlled by vira, virg, and a plant inducer. isolation of two constitutive mutants of the transcriptional activator virg, virgn54d, and virgi106l, that support vir gene expression in a vira independent manner has previously been reported. characterization of virgn54d by several groups showed considerable variation in its ability to activate vir gene transcription. in this study we demonstrate that these differences can be account ... | 1995 | 7579624 |
| synthetic antimicrobial peptide design. | to guide the design of potential plant pathogen-resistance genes, synthetic variants of naturally occurring antimicrobial gene products were evaluated. five 20-amino acid (esf1, esf4, esf5, esf6, esf13), one 18-amino acid (esf12), and one 17-amino acid (esf17) amphipathic peptide sequences were designed, synthesized, and tested with in vitro bioassays. positive charges on the hydrophilic side of the peptide were shown to be essential for antifungal activity, yet the number of positive charges co ... | 1995 | 7579625 |
| transformation of soybean (glycine max) via agrobacterium tumefaciens and analysis of transformed plants. | | 1995 | 7581657 |
| high-frequency and efficient agrobacterium-mediated transformation of arabidopsis thaliana ecotypes "c24" and "landsberg erecta" using agrobacterium tumefaciens. | | 1995 | 7581660 |
| agrobacterium tumefaciens chemotaxis protocols. | | 1995 | 7581673 |
| effect of acetosyringone on growth and oncogenic potential of agrobacterium tumefaciens. | | 1995 | 7581680 |
| study of the organization of the genomes of escherichia coli, brucella melitensis and agrobacterium tumefaciens by insertion of a unique restriction site. | tn5map, a tn5 derivative containing the 18 bp i-scei site, was delivered from a rp4-mobilizable, rk6-derived suicide vector to escherichia coli hb101, brucella melitensis and agrobacterium tumefaciens c58, which all lack natural i-scei sites in their genomes. digestion of the dna from tn5map-containing strains and analysis by pulsed-field gel electrophoresis (pfge) revealed that these derivatives contained a single transposon insertion. these digests also gave direct and independent proof for th ... | 1995 | 7582002 |
| agrobacterium radiobacter and related organisms take up fructose via a binding-protein-dependent active-transport system. | washed cells of agrobacterium radiobacter prepared from a fructose-limited continuous culture (d 0.045 h-1) transported d(-)[u-14c]fructose in a linear manner for up to 4 min at a rate several-fold higher than the rate of fructose utilization by the growing culture. d(-)[u-14c]fructose transport exhibited a high affinity for fructose (kt < 1 microm) and was inhibited to varying extents by osmotic shock, by the uncoupling agent carbonyl cyanide p-trifluoromethoxyphenylhydrazone, and by unlabelled ... | 1995 | 7582021 |
| the dnakj operon of agrobacterium tumefaciens: transcriptional analysis and evidence for a new heat shock promoter. | the dnakj operon of agrobacterium tumefaciens was cloned and sequenced and was found to be highly homologous to previously analyzed dnakj operons. transcription of this operon in a. tumefaciens was stimulated by heat shock as well as by exposure to ethanol and hydrogen peroxide. there were two transcripts representing the dnakj operon: one containing the dnak and dnaj genes and the second containing only the dnak gene. primer extension analysis indicated that transcription started from the same ... | 1995 | 7592349 |
| sequence and mutational analysis of a tartrate utilization operon from agrobacterium vitis. | the grapevine is the natural host of the tumorigenic bacterium agrobacterium vitis. most of the a. vitis isolates can use tartrate, an unusually abundant compound in grapevine. the nopaline strain, ab4, contains a 170-kb conjugative plasmid (ptrab4) encoding tartrate utilization. a 5.65-kb ptrab4 region which enables non-tartrate-utilizing agrobacterium tumefaciens to grow on tartrate was sequenced and mutagenized with the transcriptional fusion transposon tn5-uida1. this dna fragment contains f ... | 1995 | 7592429 |
| cloning and characterization of the siga gene encoding the major sigma subunit of rhizobium meliloti. | using pcr to create a probe based on conserved region 2 of sigma factors, we have cloned the siga gene coding for the major sigma factor of rhizobium meliloti. the 684-residue protein encoded by the siga gene was expressed in vitro in coupled transcription-translation experiments with r. meliloti extracts and migrated aberrantly in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. its deduced amino acid sequence is similar to that of rpod of escherichia coli and is nearly identical to t ... | 1995 | 7592490 |
| genetic analysis of nonpathogenic agrobacterium tumefaciens mutants arising in crown gall tumors. | little is known about the effect of the host on the genetic stability of bacterial plant pathogens. crown gall, a plant disease caused by agrobacterium tumefaciens, may represent a useful model to study this effect. indeed, our previous observations on the natural occurrence and origin of nonpathogenic agrobacteria suggest that the host plant might induce loss of pathogenicity in populations of a. tumefaciens. here we report that five different a. tumefaciens strains initially isolated from appl ... | 1995 | 7601840 |
| supraoperonic clustering of pca genes for catabolism of the phenolic compound protocatechuate in agrobacterium tumefaciens. | the protocatechuate branch of the beta-ketoadipate pathway comprises the last six enzymatic steps in the catabolism of diverse phenolic compounds to citric acid cycle intermediates. in this paper, the regulation and tight supraoperonic clustering of the protocatechuate (pca) genes from agrobacterium tumefaciens a348 are elucidated. a previous study found that the pcad gene is controlled by an adjacent regulatory gene, pcaq, which encodes an activator. the activator responded to beta-carboxy-cis, ... | 1995 | 7601847 |
| a two-element enhancer-inhibitor transposon system in arabidopsis thaliana. | the enhancer-inhibitor (en-i), also known as suppressor-mutator (spm-dspm), transposable element system of maize was modified and introduced into arabidopsis by agrobacterium tumefaciens transformation. a stable en/spm transposase source under control of the camv 35s promoter mediated frequent transposition of i/dspm elements. transposition occurred continuously throughout plant development over at least seven consecutive plant generations after transformation. new insertions were found at both ... | 1995 | 7603434 |
| effect of the m-ecorii methyltransferase-encoding gene on the phenotype of nicotiana tabacum transgenic cells. | the ecorii dna methyltransferase (m-ecorii; mtase) modifies a cytosine in the dna sequence ccwgg which contains a cng methylation motif characteristic of plant dna. the gene (ecoriim) encoding this mtase has been cloned into the t-dna of the wild-type agrobacterium ti-plasmid ptic58 downstream from the plant expression nopaline synthase-encoding gene promoter. nicotiana tabacum cells have been transformed with agrobacterium tumefaciens harbouring this recombinant ti-plasmid. the primary transfor ... | 1995 | 7607509 |
| trans-kingdom t-dna transfer from agrobacterium tumefaciens to saccharomyces cerevisiae. | agrobacterium tumefaciens transfers part of its tumour-inducing (ti) plasmid, the transferred or t-dna, to plants during tumourigenesis. this represents the only example of naturally occurring trans-kingdom transfer of genetic material. here we report that a.tumefaciens can transfer its t-dna not only to plant cells, but also to another eukaryote, namely the yeast saccharomyces cerevisiae. the ti plasmid virulence (vir) genes that mediate t-dna transfer to plants were found to be essential for t ... | 1995 | 7621833 |
| the agrobacterium tumefaciens virulence d2 protein is responsible for precise integration of t-dna into the plant genome. | the vird2 protein of agrobacterium tumefaciens was shown to pilot t-dna during its transfer to the plant cell nucleus. we analyze here its participation in the integration of t-dna by using a vird2 mutant. this mutation reduces the efficiency of t-dna transfer, but the efficiency of integration of t-dna per se is unaffected. southern and sequence analyses of integration events obtained with the mutated vird2 protein revealed an aberrant pattern of integration. these results indicate that the wil ... | 1995 | 7628458 |
| expression of the plum pox coat protein gene in transgenic nicotiana tabacum plants. | plant expression vector pbi 121 containing the gene encoding coat protein of plum pox virus of the skierniewice isolate (cp ppv-s) was prepared (clone pcm1). the construct was used for transformation of nicotiana tabacum plants using an agrobacterium tumefaciens based system. about 82% of kanamycin resistant plant lines contained a transgene (the sequence of cp ppv-s) but only 81% of them actively expressed the ppv-s coat protein gene as measured by rt-pcr. | 1995 | 7653168 |
| interactions of virb9, -10, and -11 with the membrane fraction of agrobacterium tumefaciens: solubility studies provide evidence for tight associations. | the eleven predicted gene products of the agrobacterium tumefaciens virb operon are believed to form a transmembrane pore complex through which t-dna export occurs. the virb10 protein is required for virulence and is a component of an aggregate associated with the membrane fraction of a. tumefaciens. removal of the putative membrane-spanning domain (amino acids 22 through 55) disrupts the membrane topology of virb10 (j. e. ward, e. m. dale, e. w. nester, and a. n. binns, j. bacteriol. 172:5200-5 ... | 1995 | 7665464 |
| inhibition of virb-mediated transfer of diverse substrates from agrobacterium tumefaciens by the incq plasmid rsf1010. | the transfer of dna from agrobacterium tumefaciens into a plant cell requires the activities of several virulence (vir) genes that reside on the tumor-inducing (ti) plasmid. the putative transferred intermediate is a single-stranded dna (t strand), covalently attached to the vird2 protein and coated with the single-stranded dna-binding protein, vire2. the movement of this intermediate out of agrobacterium cells and into plant cells requires the expression of the virb operon, which encodes 11 pro ... | 1995 | 7665465 |
| construction of chimeric beta-glucosidases with improved enzymatic properties. | the amino acid sequences of beta-glucosidases from cellvibrio gilvus and agrobacterium tumefaciens show about 40% similarity. the ph/temperature optima and stabilities and substrate specificities of the two enzymes are quite different. c. gilvus beta-glucosidase exhibits an optimum ph of 6.2-6.4 and temperature of 35 degrees c, whereas the corresponding values for a. tumefaciens are 7.2-7.4 and 60 degrees c, respectively. the substrate specificity of a. tumefaciens enzyme toward different aryl g ... | 1995 | 7665615 |
| deletion analysis and localization of sbprp1, a soybean cell wall protein gene, in roots of transgenic tobacco and cowpea. | sbprp1 is a member of the soybean (glycine max l. merr) proline-rich cell wall protein family and is expressed at high levels in root tissue. to characterize the sequences required for this expression, we have fused 1.1 kb of upstream flanking dna sequence from an sbprp1 genomic clone to a gene encoding beta-glucuronidase (gus). this construct was introduced into tobacco using agrobacterium tumefaciens-mediated transformation. histochemical staining of gus activity in transgenic tobacco indicate ... | 1993 | 7678758 |
| transgene copy number can be positively or negatively associated with transgene expression. | two different types of t-dna insert were found in tobacco plants transformed with agrobacterium tumefaciens. high-expressing (h) types had one copy of the t-dna at a locus and produced high expression of the transgene uida, as measured by uida rna levels and beta-glucuronidase activity; low-expressing (l) types had inverted repeats of the t-dna at a locus and produced low uida expression. h-types from different transformants acted additively, and cross-fertilization between two different homozyg ... | 1993 | 7678759 |
| induction of a tomato anionic peroxidase gene (tap1) by wounding in transgenic tobacco and activation of tap1/gus and tap2/gus chimeric gene fusions in transgenic tobacco by wounding and pathogen attack. | the anionic peroxidase genes of tomato, tap1 and tap2, are induced by wounding in tomato fruits and by elicitor treatment in cell suspension cultures. these homologous genes code for anionic peroxidases that are postulated to cause polymerization of the phenolic residues into wall polymers in wound-healing and pathogen-infected tissues. an expression construct containing the entire tap1 gene with its 5' and 3' flanking sequences was introduced into tobacco by agrobacterium tumefaciens-mediated g ... | 1993 | 7678769 |
| preparation, optimization and characterization of a polyphenylalanine synthetizing system from agrobacterium tumefaciens. | a very active cell-free translation system was prepared from agrobacterium tumefaciens, a bacterium broadly used to transfect plant cells to introduce foreign genes and one that produces tumours in plants. once optimized for mg2+, nh4+, high speed supernatant s 370, purified ribosomes and time, the system translates polyuridylic acid very efficiently. a. tumefaciens purified ribosomes were inhibited in vitro by several well-known translational inhibitors including some ribosome-inactivating prot ... | 1993 | 7693097 |
| inhibition of viroid infection by antisense rna expression in transgenic plants. | complex formation between different antisense rnas directed against either plus-strand or minus-strand sequences of the potato spindle tuber viroid (pstvd) was studied using temperature-gradient gel electrophoresis and immunochemical detection with an antibody specific for double-stranded rna. short minus-strand sequences were directed against the upper central conserved region (uccr) of plus-strand viroid replication intermediates, a plus-strand corresponding to the left half of the rod-like se ... | 1994 | 7695839 |
| sucrose analogues modified at position 3: chemoenzymatic synthesis and inhibition studies of dextransucrases. | conditions for the large-scale (molar) oxidation of sucrose by agrobacterium tumefaciens were improved, thus leading to homogeneous solutions of 3-ketosucrose in 40% yield. treatment of this solution with hydroxylamine or methoxylamine afforded the corresponding oximes 3a and 3b (isolated as acetates) in excellent yield. dissolving-metal reduction of these oximes gave mixtures of amino disaccharides in which the gluco epimer (3-amino-3-deoxysucrose) was predominant. a more efficient approach to ... | 1995 | 7697661 |
| a chromosomal cluster of genes encoding adp-glucose synthetase, glycogen synthase and phosphoglucomutase in agrobacterium tumefaciens. | | 1995 | 7698662 |
| expression of giant silkmoth cecropin b genes in tobacco. | cecropin b is a small antibacterial peptide from the giant silkmoth hyalophora cecropia. to reveal the potential of this peptide for engineering bacterial disease resistance into crops, several cecropin b gene constructs were made either for expression in the cytosol or for secretion. all constructs were cloned in a plant expression vector and introduced in tobacco via agrobacterium tumefaciens. a cdna-derived cecropin b gene construct lacking the amino-terminal signal peptide was poorly express ... | 1995 | 7704053 |
| tissue- and cell-specific expression of a cinnamyl alcohol dehydrogenase promoter in transgenic poplar plants. | cinnamyl alcohol dehydrogenase (cad) which catalyses the synthesis of the cinnamyl alcohols, the immediate precursors of lignins, from the corresponding cinnamaldehydes is considered to be a highly specific marker for lignification. we have isolated and characterized a cad genomic clone from eucalyptus, a woody species of economic importance. the full-length promoter (eucad, 2.5 kb) and a series of 5' deletions were fused to the beta-glucuronidase (gus) reporter gene. these constructs were teste ... | 1995 | 7727744 |
| sequence and distribution of is1312: evidence for horizontal dna transfer from rhizobium meliloti to agrobacterium tumefaciens. | two novel insertion sequences, is1312 and is1313, were found in ptibo542, the ti plasmid of agrobacterium tumefaciens strains bo542 and a281. nucleotide sequencing and southern hybridization revealed that is1312 and is1313 are homologous to rhizobium meliloti isrm1 and isrm2, respectively. is1312, isrm1, and another agrobacterium insertion sequence, is426, belong to the same is3 family of insertion sequences; however, is1312 is more closely related to the rhizobium isrm1 than it is to the agroba ... | 1995 | 7730290 |
| [agrobacterium radiobacter bacteremia. study of 2 cases and review of the literature]. | agrobacteria are small gramnegative bacilli which produce tumors in different vegetal species and occasionally are human pathogens. | 1995 | 7734495 |
| marine algae that display anti-tumorigenic activity against agrobacterium tumefaciens. | thirty-five extracts representing different seasonal growths of 17 marine algal species collected from the alexandria coast were tested for anti-tumorigenic activity against agrobacterium tumefaciens galls on potato discs. eleven extracts (nine species) displayed > 20% inhibition of tumor initiation, with three of these (codium tomentosum, winter; jania rubens, summer; padina pavonia, winter) displaying relatively high activity. bacterial viability tests showed that the inhibitory effects were d ... | 1995 | 7750733 |
| different relative importances of the par operons and the effect of conjugal transfer on the maintenance of intact promiscuous plasmid rk2. | the par region of the broad-host-range, incp alpha plasmid rk2 has been implicated as a stability determinant by its ability to enhance the maintenance of mini-rk2 plasmids or heterologous replicons in a growing population of host cells. the region consists of two operons: parcba, which encodes a multimer resolution system, and parde, which specifies a postsegregational response mechanism that is toxic to plasmidless segregants. to assess the importance of this region to the stable maintenance o ... | 1995 | 7751288 |
| a homolog of the rhizobium meliloti nitrogen fixation gene fixn is involved in the production of a microaerobically induced oxidase activity in the phytopathogenic bacterium agrobacterium tumefaciens. | hybridization analysis using the rhizobium meliloti nitrogen fixation gene fixn as a probe revealed the presence of a homologous dna region in the phytopathogenic bacterium agrobacterium tumefaciens. hybridization signals were also detected with total dnas of rhizobium leguminosarum bv. phaseoli, rhodobacter capsulatus and escherichia coli, but not those of xanthomonas campestris pv. campestris and pseudomonas putida. the hybridizing fragment from a. tumefaciens was cloned and sequenced. the pre ... | 1995 | 7753030 |
| molecular analysis of the rhizobium meliloti mucr gene regulating the biosynthesis of the exopolysaccharides succinoglycan and galactoglucan. | the rhizobium meliloti tn5 mutant rm3131, producing galactoglucan (eps ii) instead of succinoglycan (eps i), was complemented by a 3.6-kb ecori-fragment of the rhizobium meliloti genome. sequencing of this fragment revealed six open reading frames (orfs). the orf found to be affected in the mutant rm3131 codes for a putative protein of 15.7 kda and forms a monocistronic transcriptional unit. further genetic analysis revealed that the gene mutated in rm3131 is identical to the previously describe ... | 1995 | 7756693 |
| immunity to potato mop-top virus in nicotiana benthamiana plants expressing the coat protein gene is effective against fungal inoculation of the virus. | nicotiana benthamiana stem tissue was transformed with agrobacterium tumefaciens harboring a binary vector containing the potato mop-top virus (pmtv) coat protein (cp) gene. pmtv cp was expressed in large amounts in some of the primary transformants. the five transgenic lines which produced the most cp were selected for resistance testing. flowers on transformed plants were allowed to self-fertilize. transgenic seedlings selected from the t1 seed were mechanically inoculated with two strains of ... | 1995 | 7756694 |
| isolation and characterization of a locus from azospirillum brasilense sp7 that complements the tumorigenic defect of agrobacterium tumefaciens chvb mutant. | the chromosomal virulence gene chvb of agrobacterium tumefaciens is required for pathogenesis. a dna fragment from the chvb locus can hybridize to dna from azospirillum brasilense sp7. this dna fragment could restore the tumorigenic activity of the chvb mutant strain a. tumefaciens a1011 towards leaf disks of nicotiana tabacum. an nh2-terminal open reading frame, 480 codons long, was most likely responsible for the restoration of the tumorigenic activity. the a. brasilense sequence showed good h ... | 1995 | 7756697 |
| divergent transcription and a remote operator play a role in control of expression of a nopaline catabolism promoter in agrobacterium tumefaciens. | the nocp-nocr divergent gene arrangement of the nopaline catabolism (noc) operon of the agrobacterium tumefaciens ti plasmid ptit37 was examined with respect to the expression of the nocp promoter. under repressive conditions, i.e. in the absence of nopaline, four distinct levels of pnocp expression were observed. the lowest level of expression, i.e. full repression, was detected in the presence of the nocr repressor, together with the remote noc operator and productive transcription from the di ... | 1995 | 7759474 |
| a 17-kda nicotiana tabacum cell-wall peptide acts as an in-vitro inhibitor of the cell-wall isoform of acid invertase. | when cell-wall invertase (cwi) from nicotiana tabacum l. cell-suspension cultures, either non-transformed or transformed with agrobacterium tumefaciens, was salt-eluted from intact cells and purified on sulfopropyl-sephadex (sps) by ph-gradient elution, the enzyme lost about 50% of its activity during a 1-h incubation at ph 4.8. however, western-blot analysis indicated no appreciable enzyme degradation. re-chromatography of cwi peak fractions on sps using nacl-gradient elution showed the presenc ... | 1994 | 7764874 |
| sensitivity of translation by brevibacterium lactofermentum ribosomes to type 1 and type 2 ribosome-inactivating proteins. | an active cell-free translation system was prepared from brevibacterium lactofermentum, a gram-positive bacteria used in molecular cloning and protein expression. the system contained high speed postribosomal supernatant (s 370), purified ribosomes and a trna mixture from escherichia coli, and synthesized polyuridylic acid-directed polyphenylalanine once optimized for mono and divalent ions, time, and temperature. the translation system was evaluated for sensitivity to several translational inhi ... | 1994 | 7765276 |
| cellular localization and functional analysis of the protein encoded by the chromosomal virulence gene(acvb) of agrobacterium tumefaciens. | a chromosomal virulence gene, acvb, of agrobacterium tumefaciens [j. bacteriol., 175, 3208-3212 (1993)] was over-expressed in escherichia coli. a 47-kda protein was produced and localized in the periplasmic space of e. coli. amino acid sequence analysis of its n-terminal demonstrated that a signal peptide of 24 amino acids was cleaved from the pre acvb protein to produce the mature 47-kda protein. western-blot analysis using the antiserum against the acvb protein detected a 47-kda protein in the ... | 1994 | 7765595 |
| transgene-mediated auxin overproduction in arabidopsis: hypocotyl elongation phenotype and interactions with the hy6-1 hypocotyl elongation and axr1 auxin-resistant mutants. | transgenic arabidopsis thaliana plants constitutively expressing agrobacterium tumefaciens tryptophan monooxygenase (iaam) were obtained and characterized. arabidopsis plants expressing iaam have up to 4-fold higher levels of free indole-3-acetic acid (iaa) and display increased hypocotyl elongation in the light. this result clearly demonstrates that excess endogenous auxin can promote cell elongation in a whole plant. interactions of the auxin-overproducing transgenic plants with the phytochrom ... | 1995 | 7766890 |
| characterization of a human glycoprotein (erythropoietin) produced in cultured tobacco cells. | erythropoietin (epo), a glycoprotein that regulates the formation of erythrocytes in mammals, was produced in cultured tobacco by2 cells (nicotiana tabacum l. cv. bright yellow 2) by introducing human epo cdna via agrobacterium tumefaciens-mediated gene transfer. epo was correctly processed and subsequently penetrated the plasma membrane of tobacco cells. however, it remained attached to the cell wall and was not released into the culture medium. although epo produced by tobacco cells was glycos ... | 1995 | 7766897 |
| transfer of t-dna from agrobacterium to the plant cell. | agrobacterium tumefaciens is the causative agent of crown gall, a disease of dicotyledonous plants characterized by a tumorous phenotype. earlier in this century, scientific interest in a. tumefaciens was based on the possibility that the study of plant tumors might reveal mechanisms that were also operating in animal neoplasia. in the recent past, the tumorous growth was shown to result from the expression of genes coded for by a dna segment of bacterial origin that was transferred and became s ... | 1995 | 7770515 |
| transgenic tobacco plants expressing a truncated form of the pamv capsid protein (cp) gene show cp-mediated resistance to potato aucuba mosaic virus. | four constructs of the potato aucuba mosaic virus (pamv) coat protein (cp) gene were engineered for expression in tobacco plants: the full-length cp sequence (fl cp), two truncated forms--one at the n terminus (46 amino acid residues are deleted) (nt138), one in the conserved core portion (86 amino acids deleted) (ct258) of the gene--and an antisense rna construct. these constructs were introduced into tobacco plants (nicotiana tabacum) via agrobacterium tumefaciens-mediated transformation. the ... | 1995 | 7772804 |
| broad resistance to tospoviruses in transgenic tobacco plants expressing three tospoviral nucleoprotein gene sequences. | transgenic tobacco plants have been obtained expressing nucleoprotein (n) gene sequences of three different tospoviruses known to affect vegetable crops: tomato spotted wilt virus (tswv), tomato chlorotic spot virus (tcsv), and groundnut ringspot virus (grsv). the chimeric plant transformation vector used comprised the three viral n gene sequences, each with a copy of the camv 35s promoter and the nos terminator. despite the high levels of homology between the different n gene sequences (74-82%) ... | 1995 | 7772807 |
| functional expression of saccharomyces cerevisiae cyp51a1 encoding lanosterol-14-demethylase in tobacco results in bypass of endogenous sterol biosynthetic pathway and resistance to an obtusifoliol-14-demethylase herbicide inhibitor. | nicotiana tabacum protoplasts have been transformed by agrobacterium tumefaciens containing a t-dna in which the gene cyp51a1 encoding lanosterol-14-demethylase (lan14dm) from saccharomyces cerevisiae is under the control of a cauliflower mosaic virus (camv) 35s promoter. two transformants strongly expressed the lan14dm as shown by northern and western experiments. these transgenic calli were killed by lab 170250f (lab) (a phytotoxic fungicide inhibiting both plant obtusifoliol-14-demethylase (o ... | 1995 | 7773307 |
| recombination between prokaryotic and eukaryotic dna: integration of agrobacterium tumefaciens t-dna into the plant genome. | | 1995 | 7779513 |
| agrobacterium tumefaciens virb11 protein requires a consensus nucleotide-binding site for function in virulence. | virb11, one of the 11 genes of the virb operon, is absolutely required for transport of t-dna from agrobacterium tumefaciens into plant cells. previous studies reported that virb11 is an atpase with autophosphorylation activity and localizes to the inner membrane even though the protein does not contain the consensus n-terminal export sequence. in this report, we show that virb11 localizes to the inner membrane even in the absence of other tumor-inducing (ti) plasmid-encoded proteins. to facilit ... | 1995 | 7798144 |
| studies on the extracellular polysaccharide from agrobacterium radiobacter biovar i s-1231. | a strain s-1231 isolated from specimen of soil around beijing area is gram-negative, non-sporing, motile by peritrichous flagella. it produces exopolysaccharide succinoglycan from carbohydrates as its carbon source but not starch and cellulose. acid is produced during fermentation of glucose. growing for 12-24 hr, the cells are rods 0.7-0.8 x 1.3-1.5 microns, round ended, single or in pairs. colonies on nutrient agar plate are unpigmented, circular, raised, smooth and moist-glistening, edge enti ... | 1994 | 7803689 |
| interspecies regulation of the reca gene of gram-negative bacteria lacking an e. coli-like sos operator. | the reca genes of agrobacterium tumefaciens, rhizobium meliloti, rhizobium phaseoli and rhodobacter sphaeroides, species belonging to the alpha-group bacteria of the proteobacteria class, have been fused in vitro to the lacz gene of escherichia coli. by using a mini-tn5 transposon derivative, each of these reca-lacz fusions was introduced into the chromosome of each of the four species, and into that of e. coli. the reca genes of three of the alpha bacteria are induced by dna damage when inserte ... | 1994 | 7808403 |
| a new regulatory element modulates homoserine lactone-mediated autoinduction of ti plasmid conjugal transfer. | conjugal transfer of the agrobacterium tumefaciens nopaline-type ti plasmid ptic58 is induced by agrocinopines a and b, opines secreted by crown gall tumors induced by the bacterium. this regulation functions through the transcriptional repressor, accr. however, actual transcription of the tra genes is regulated by autoinduction through the activator trar and the substituted homoserine lactone second messenger, agrobacterium autoinducer (aai). we have identified a new regulatory element that mod ... | 1995 | 7814335 |
| in planta transformation of arabidopsis thaliana. | transformants of arabidopsis thaliana can be generated without using tissue culture techniques by cutting primary and secondary inflorescence shoots at their bases and inoculating the wound sites with agrobacterium tumefaciens suspensions. after three successive inoculations, treated plants are grown to maturity, harvested and the progeny screened for transformants on a selective medium. we have investigated the reproducibility and the overall efficiency of this simple in planta transformation p ... | 1994 | 7816046 |
| an essential virulence protein of agrobacterium tumefaciens, virb4, requires an intact mononucleotide binding domain to function in transfer of t-dna. | the 11 gene products of the agrobacterium tumefaciens virb operon, together with the vird4 protein, are proposed to form a membrane complex which mediates the transfer of t-dna to plant cells. this study examined one putative component of that complex, virb4. a deletion of the virb4 gene on the ti plasmid ptia6nc was constructed by replacing the virb4 gene with the kanamycin resistance-conferring nptii gene. the virb4 gene was found to be necessary for virulence on plants and for the transfer of ... | 1994 | 7830718 |
| initiation of agrobacterium tumefaciens t-dna processing. purified proteins vird1 and vird2 catalyze site- and strand-specific cleavage of superhelical t-border dna in vitro. | t-dna processing during agroinfection of plants is initiated by site- and strand-specific incision at the t-dna border sequences of the ti plasmid. two proteins are required for this reaction: vird2 (49.6 kda), catalyzing a site-specific cleaving-joining reaction on single-stranded dna in vitro (pansegrau, w., schoumacher, f., hohn, b., and lanka, e. (1993) proc. natl. acad. sci. u.s.a. 90, 11538-11542), and vird1 (16.1 kda), an accessory protein required for vird2-mediated specific cleavage of ... | 1995 | 7836390 |
| nmr analysis of succinoglycans from different microbial sources: partial assignment of their 1h and 13c nmr spectra and location of the succinate and the acetate groups. | in order to obtain information on the location of succinate and acetate groups, comparative nmr analyses were carried out on succinoglycans from different microbial sources by using conventional and advanced nmr techniques. in particular, one-dimensional, 1h and 13c nmr spectra were recorded for qualitative and quantitative analysis on native high-molecular-weight succinoglycans (both in the na+ salt and free-acid forms) from pseudomonas sp. ncib 11592, agrobacterium radiobacter a201-25, rhizobi ... | 1994 | 7842440 |
| localization and topology of virb proteins of agrobacterium tumefaciens. | agrobacterium tumefaciens causes tumors on plants by transferring part of its ti (tumor inducing) plasmid, the t-dna or transferred dna, to plant cells. the virb operon, the largest operon of the virulence (vir) region located on the ti plasmid, is necessary for tumor induction on all plant species. previously, the complete nucleotide sequences of the virb operons of several ti plasmids of a. tumefaciens were determined. the 11 predicted proteins mostly have signal sequences and/or hydrophobic d ... | 1994 | 7846145 |
| construction and characterization of a chimeric beta-glucosidase. | the amino acid sequences of beta-glucosidases from cellvibrio gilvus and agrobacterium tumefaciens show significant similarity in most of the parts. however, the ph/temperature optima and stabilities of the two enzymes are quite different. c. gilvus beta-glucosidase exhibits an optimum ph of 6.2-6.4 and temperature of 35 degrees c, whereas the corresponding values for a. tumefaciens are 7.2-7.4 and 60 degrees c respectively. to analyse these properties further, a chimeric beta-glucosidase was co ... | 1995 | 7848268 |
| metabolic and structural changes in pseudomonas aeruginosa, achromobacter cdc and agrobacterium radiobacter cells injured in parenteral fluids. | the long term metabolic changes of three oxidase positive microorganisms (pseudomonas aeruginosa, agrobacterium radiobacter and achromobacter cdc) all isolated from aquatic environment, were defined after they were inoculated in three parenteral fluids: lactated ringer's solution, sodium chloride 0.9% and dextrose 5%. the number of microorganisms introduced into the parenteral products was adjusted to 10(5) bacteria/ml and left at room temperature (20-22 degrees c) for 30 days. their enzymatic a ... | 1994 | 7850451 |
| differentiation of brucella abortus bv. 1, 2, and 4, brucella melitensis, brucella ovis, and brucella suis bv. 1 by pcr. | several pcr assays which identify the genus brucella but do not discriminate among species have been reported. we describe a pcr assay that comprises five oligonucleotide primers which can identify selected biovars of four species of brucella. individual biovars within a species are not differentiated. the assay can identify three biovars (1, 2, and 4) of b. abortus, all three biovars of b. melitensis, biovar 1 of b. suis, and all b. ovis biovars. these biovars include all of the brucella specie ... | 1994 | 7852552 |
| replication of the broad-host-range plasmid rk2: isolation and characterization of a spontaneous deletion mutant that can replicate in agrobacterium tumefaciens but not in escherichia coli. | two spontaneous deletions of a derivative of the broad-host-range plasmid rk2 were isolated from agrobacterium tumefaciens. the two deletions have lost 56 and 505 bp, respectively, near the origin of replication (oriv). of the eight 17-bp repeats present in the rk2 oriv, the smaller deletion has lost the first two while the larger one has lost the first three. the deletions led to a significant increase (3- to 7-fold) in plasmid copy number in a. tumefaciens, indicating their importance in copy ... | 1995 | 7854315 |
| host recognition by the vira, virg two-component regulatory proteins of agrobacterium tumefaciens. | agrobacterium tumefaciens contains about 25 vir genes localized on a 200-kb tumour-inducing (ti) plasmid that direct a conjugation-like transfer of tumorigenic dna from the bacterium to the nuclei of infected plant cells. these genes are strongly and coordinately induced during infection in response to three different classes of stimuli which are thought to be key chemical features of a typical wound site. these stimuli are (i) guaiacol and syringol derivatives such as acetosyringone, (ii) sugar ... | 1994 | 7855433 |
| genes required for cellulose synthesis in agrobacterium tumefaciens. | a region of the chromosome of agrobacterium tumefaciens 11 kb long containing two operons required for cellulose synthesis and a part of a gene homologous to the fixr gene of bradyrhizobium japonicum has been sequenced. one of the cellulose synthesis operons contained a gene (cela) homologous to the cellulose synthase (bsca) gene of acetobacter xylinum. the same operon also contained a gene (celc) homologous to endoglucanase genes from a. xylinum, cellulomonas uda, and erwinia chrysanthemi. the ... | 1995 | 7860585 |
| mechanism of cellulose synthesis in agrobacterium tumefaciens. | extracts of agrobacterium tumefaciens incorporated udp-[14c]glucose into cellulose. when the extracts were fractionated into membrane and soluble components, neither fraction was able to synthesize cellulose. a combination of the membrane and soluble fractions restored the activity found in the original extracts. extracts of cellulose-minus mutants showed no significant incorporation of udp-glucose into cellulose. when mixtures of the extracts were made, the mutants were found to fall into two g ... | 1995 | 7860586 |
| the octopine-type ti plasmid ptia6 of agrobacterium tumefaciens contains a gene homologous to the chromosomal virulence gene acvb. | although the majority of genes required for the transfer of t-dna from agrobacterium tumefaciens to plant nuclei are located on the ti plasmid, some chromosomal genes, including the recently described acvb gene, are also required. we show that acvb shows 50% identity with the product of an open reading frame, designated virj, that is found between the vira and virb genes in the octopine-type ti plasmid ptia6. this reading frame is not found in the nopaline-type ti plasmid ptic58. acvb is require ... | 1995 | 7860597 |
| targeting the maize t-urf13 product into tobacco mitochondria confers methomyl sensitivity to mitochondrial respiration. | the urf13 protein, which is encoded by the maize mitochondrial t-urf13 gene, is thought to be responsible for pathotoxin and methomyl sensitivity and male sterility. we have investigated whether t-urf13 confers toxin sensitivity and male sterility when expressed in another plant species. the coding sequence of t-urf13 was fused to a mitochondrial targeting presequence, placed under the control of the cauliflower mosaic virus 35s promoter, and introduced into tobacco by agrobacterium tumefaciens- ... | 1995 | 7862654 |
| identification of the agrobacterium tumefaciens c58 t-dna genes e and f and their impact on crown gall tumour formation. | dna sequence analysis of the 4.4 kilobases (kb) eco ri fragment 14 from t-dna of agrobacterium tumefaciens c58 revealed three open reading frames. one of them (945 bp) was supposed to encode the transcript e, the function of which has not been identified to date. furthermore, a so far undescribed open reading frame (1035 bp) was identified, located in the centre of the eco ri fragment 14 and termed gene f. the third open reading frame encoded the carboxy-terminal part of the agrocinopine synthas ... | 1995 | 7865795 |
| variability of peptidoglycan structural parameters in gram-negative bacteria. | muropeptide composition of peptidoglycan from the gram-negative bacteria aeromonas sp., acinetobacter acetoaceticus, agrobacterium tumefaciens, enterobacter cloacae, proteus morganii, pseudomonas aeruginosa, pseudomonas putida, vibrio parahaemolyticus yersinia enterocolitica and escherichia coli, was analyzed by hplc. in all instances peptidoglycan was built up from the same subunits. a wide disparity in the relative abundance of muropeptides and all structural parameters was observed. the contr ... | 1995 | 7867925 |
| identification of a novel rhizobium meliloti nodulation efficiency nfe gene homolog of agrobacterium ornithine cyclodeaminase. | the nfe genes located on the large plasmid prmegr4b are involved in the nodulation efficiency and competitiveness of rhizobium meliloti gr4 on alfalfa roots. one hundred twenty-eight base-pairs downstream of nfe2 gene we found an open reading frame designated orfc, 970 bp long and potentially coding for a 320 amino acid long protein. the amino acid sequence of the putatively encoded orfc product shows similarity with ornithine cyclodeaminase (ocd) of agrobacterium tumefaciens an unusual enzyme t ... | 1994 | 7873778 |
| acquisition and transmission of agrobacterium by the whitefly bemisia tabaci. | whiteflies transmit many different plant pathogens. we show here that the whitefly bemisia tabaci can also acquire agrobacterium tumefaciens from liquid cultures and from crown galls, and transmit it to plants. cloned tomato yellow leaf curl virus (tylcv) dna and a. tumefaciens tumor-inducing functions were used as reporter genes. whiteflies were fed through membranes on cultures of agrobacterium at::pty4 containing a dimeric copy of an infectious tylcv genomic clone between the t-dna borders of ... | 1994 | 7873782 |
| a new agrobacterium strain isolated from aerial tumors on ficus benjamina l. | crown gall tumors, collected from branches of 1-year-old weeping fig (ficus benjamina l.) trees, yielded both tumorigenic and nonpathogenic agrobacteria. on the basis of classical diagnostic tests, the nonpathogenic strains were identified as agrobacterium tumefaciens, whereas the tumorigenic strains could not be assigned to any of the known terrestrial agrobacterium spp. the tumorigenic strains also differed from other members of the genus by producing more acid from mannitol. according to clus ... | 1995 | 7887626 |
| light-induced expression of ipt from agrobacterium tumefaciens results in cytokinin accumulation and osmotic stress symptoms in transgenic tobacco. | cytokinins are plant growth regulators that induce shoot formation, inhibit senescence and root growth. experiments with hydroponically grown tobacco plants, however, indicated that exogenously applied cytokinin led to the accumulation of proline and osmotin. these responses were also associated with environmental stress reactions, such as salt stress, in many plant species. to test whether increased endogenous cytokinin accumulation led to nacl stress symptoms, the gene ipt from agrobacterium t ... | 1995 | 7888614 |
| common ancestry between incn conjugal transfer genes and macromolecular export systems of plant and animal pathogens. | the dna sequence of a cluster of pkm101 conjugal transfer genes was determined and aligned with the genetic map of the plasmid. eighteen genes were identified, at least eight and probably 11 of which are required for efficient conjugation. these tra genes are homologous to and colinear with genes found in the virb operon of agrobacterium tumefaciens ti plasmids. seven pkm101 tra genes are also homologous to ptl genes of bordetella pertussis, which direct the export of pertussis toxin. we used tn ... | 1994 | 7891554 |
| the cconoqp gene cluster codes for a cb-type cytochrome oxidase that functions in aerobic respiration of rhodobacter capsulatus. | the genes for a new type of a haem-copper cytochrome oxidase were cloned from rhodobacter capsulatus strain 37b4, using the bradyrhizobium japonicum fixnoqp gene region as a hybridizing probe. four genes, probably organized in an operon (cconoqp), were identified; their products share extensive amino acid sequence similarity with the fixn, o, q and p proteins that have recently been shown to be the subunits of a cb-type oxidase. ccon is a b-type cytochrome, ccoo and ccop are membrane-bound mono- ... | 1994 | 7891558 |
| dna rearrangement associated with the integration of t-dna in tobacco: an example for multiple duplications of dna around the integration target. | transferred dna (t-dna) of the tumor-inducing (ti) plasmid is transferred from agrobacterium tumefaciens to plant cells and is stably integrated into the plant nuclear genome. by the inverse polymerase chain reaction dna fragments were amplified that contained the t-dna/plant dna junctions from the total dna of a transgenic tobacco plant that had a single copy of the t-dna in a repetitive region of its genome. a dna fragment containing the target site was amplified from the total dna of non-tran ... | 1995 | 7894506 |