Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| characterization of different plaque-forming and defective temperate phages in agrobacterium. | four agrobacterium tumefaciens temperate phages (pb2a, pb6(omega), pv-1(lv-1) and ps8), were shown to have the same genome size. moreover hybridization experiments by the heteroduplex method and electron microscopy showed a 100% homology between these four phage genomes. indications for lysogeny were found by direct means for the agrobacterum timefaciens strain 396, agrobacterium radiobacter strain 8149 and agrobacterium species 0362 and by the electron microscope negative staining technique fo ... | 1975 | 1123610 |
| attempts to detect agrobacterium tumefaciens and bacteriophage ps8 dna in crown gall tumors by dna-dna-filter hybridization. | a systematic study of the dna-dna-filter reaction is presented which measures its ability to detect small amounts of simple dna (bacterial or bacteriophage) in model mixtures of dna immobilized on filters. saturation curves show qualitatively that significant binding occurs when there is 10% agrobacterium tumefaciens dna on the filter but not 1%. ps8 bacteriophage dna is detectable at a level of 0.1%. true saturation is not attained in the bacterial dna reaction : radioactivity bound represents ... | 1975 | 1125316 |
| protein turnover measured by 18-o exchange with h2-18o in non-growing cells of agrobacterium tumefaciens. | 1975 | 1133576 | |
| plasmid required for virulence of agrobacterium tumefaciens. | the irreversible loss of crown gall-inducing ability of agrobacterium tumefaciens strain c-58 during growth at 37 c is shown to be due to loss of a large plasmid (1.2 x 10-8 daltons). the gene responsible for this high rate of plasmid loss at elevated temperatures seems to be located on the plasmid. in addition, another spontaneous avirulent variant, a. tumefaciens strain iibnv6 is shown to lack the virulence plasmid which its virulent sibling strain, iibv7, possesses. deoxyribonucleic acid reas ... | 1975 | 1141196 |
| studies on agrobacterium tumefaciens. iv. nonreplication of the bacterial dna in mung beam (phaseolus aureus). | 1975 | 1147920 | |
| agrocin 84 sensitivity: a plasmid determined property in agrobacterium tumefaciens. | it was shown for some oncogenic agrobacterium tumefaciens strains that agrocin 84 sensitivity is determined by the presence of a large closed circular dna plasmid, called the ti-plasmid. whereas wild-type strain c58 is agrocin 84 sensitive, all ti-plasmid cured derivatives were found to be fully resistant. moreover all independently isolated agrocin 84 resistant colonies were stably non-oncogenic and plasmid negative. in a growth experiment carried out at 37 degrees c it was shown that the ki ... | 1975 | 1152843 |
| growth dynamics of agrobacterium tumefaciens in chemostat cultures limited by carbon source and mineral nutrients. | agrobacterium tumefaciens was grown in a chemostat in a chemically-defined medium which hs alpha-methyl d-glucoside, magnesium, manganese, phosphate or urea as the growth-limiting nutrient. steady-state biomass concentrations were dependent on the specific growth rate of the organism when alpha-methyl d-glucoside, manganese or phosphate were growth-limiting nutrients. during magnesium-limited growth, large undamped oscillations in biomass concentration occurred. in all chemostat cultures a varia ... | 1975 | 1156102 |
| the ribosomal ribonucleic acid of agrobacterium tumefaciens. | the 23s rrna of agrobacterium tumefaciens contains at least two nicks which result in the formation of rna components with mol.wts. of 0.52 x 10(6) and 0.48 x 10(6). thus under the usual conditions of extraction and analysis, no 23s rrna was recovered from the bacterium. the experiments show that 23s rrna is synthesized as a continuous chain, in which one or two nicks are formed almost immediately near the ends of the molecule and an additional nick in the middle at a later time. | 1975 | 1191256 |
| structure and biosynthesis of the ribosomal ribonucleic acids from the oncogenic bacterium agrobacterium tumefaciens. | the rrna of the oncogenic bacterium agrobacterium tumefaciens was extracted by several methods and analysed by polyacrylamide-gel electrophoresis. the large rrna of this bacterium is degraded in vivo during the maturation of the ribosome. the influence of mg2+ and denaturation on degradation of 23s rna was studied. in pulse and chase experiments, we identified two precursors of the rrna with mol.wts. of 1.04 x 10(6) and 0.70 x 10(6). from studies of the structure of the large rrna, we propose th ... | 1975 | 1191257 |
| on the question of integration of agrobacterium tumefaciens deoxyribonucleic acid by tomato plants. | treatment of tomato plants with agrobacterium tumefaciens causes subsequently administered [3h]thymidine to be preferentially incorporated into a satellite deoxyribonucleic acid (dna) whose buoyant density is between that of bacterial dna (rho = 1.718 g/cm3) and plant main band dna (rho = 1.692 g/cm3). satellite dna upon shearing or sonic treatment releases fragments of higher and lower buoyant density, as reported by earlier investigators. the satellite has no significant base sequence homology ... | 1975 | 1194235 |
| factors influencing the formation and stability of d-glucoside 3-dehydrogenase activity in cultures of agrobacterium tumefaciens. | d-glucoside 3-dehydrogenase specific activity in agrobacterium tumefaciens was maximal towards the end of the exponential growth phase of batch cultures; over 90% of the activity disappeared within the next 15 h. manganese ions, although essential for growth of the organism, strongly repressed d-glucoside 3-dehydrogenase synthesis in sucrose medium but had little effect when the carbon source was methyl alpha-d-glucoside. d-glucoside 3-dehydrogenase activity increased linearly with increasing sp ... | 1975 | 1194891 |
| effect on microorganisms of volatile compounds released from germinating seeds. | volatile compounds evolved from germinating seeds of slash pine, bean, cabbage, corn, cucumber, and pea were evaluated for their ability to support growth of microorganisms in liquid mineral salts media lacking a carbon source. growth of eight bacteria was measured turbidimetrically and of six fungi as dry weight of mycelium. volatiles caused increased growth of pseudomonas fluorescens, bacillus cereus, erwinia carotovora, agrobacterium tumefaciens, a. radiobacter, rhizobium japonicum, mucor muc ... | 1975 | 1201509 |
| on the isolation of ti-plasmid from agrobacterium tumefaciens. | an efficient lysis method for agrobacterium cells was developed, which allows a reproducible isolation of the tumor inducing (ti)-plasmid. the lysis method is based on the sensitivity of this bacterium to incubation with lysozyme, n-dodecylamine,edta, followed by sarkosyl, after growth in the presence of carbenicillin. we also present a procedure for the isolation of the ti-plasmid on a large scale, that might be used for the mass isolation of other large plasmids which like the ti-plasmid, can ... | 1976 | 1257056 |
| octopine as a marker for the induction of tumorous growth by agrobacterium tumefaciens strain b6. | 1976 | 1267817 | |
| role of agrobacterium cell envelope lipopolysaccharide in infection site attachment. | lipopolysaccharide (lps) isolated from agrobacterium tumefaciens inhibited tumor induction by virulent bacteria. lps from site-binding strains was not effective if added to the plant wound shortly after the bacteria, and lps from avirulent, non-site-binding strains of agrobacterium was not inhibitory regardless of the order of addition. however, lps and whole cells of avirulent strains nt1 and iibnv6, which lack of agrobacterim virulence plasmid, were inhibitory. chromosomal deoxyribonucleic aci ... | 1976 | 1278998 |
| evidence for sense rna-mediated protection to pvyn in tobacco plants transformed with the viral coat protein cistron. | the coat protein (cp) cistron of the tobacco veinal necrosis strain of potato virus y (pvyn), supplemented with translational start signals, was cloned into an agrobacterium tumefaciens ti transformation vector. transformation of tobacco leaf discs resulted in 99 transgenic lines which were subsequently analysed for the presence and expression, at both the transcriptional and translational level, of the cp-gene. although cp-specific rna transcripts were produced in all plants no cp could be dete ... | 1992 | 1280473 |
| ubiquitin genes are differentially regulated in protoplast-derived cultures of nicotiana sylvestris and in response to various stresses. | four ubiquitin mrna size classes were found to be differentially regulated in mesophyll protoplast-derived cultures of nicotiana sylvestris. three mrna families of 1.9, 1.6 and 1.35 kb were expressed as soon as protoplasts were isolated. the 1.9 and 1.6 kb size classes were transiently expressed during the first hours of culture, whereas the level of expression of the 1.35 kb size class was maintained as long as cells kept dividing. a 0.7 kb mrna size class started to be expressed just before th ... | 1992 | 1281439 |
| antiplasmid activity: loss of bacterial resistance to antibiotics. | the antiplasmid activity of tricyclic compounds, e.g. phenothiazines, dibenzoazepines, dibenzocykloheptene derivatives and some stereoisomers, was shown on e. coli in vitro. some ring-substituted phenothiazine and cannabis derivatives had only an antibacterial effect. promethazine, a selected phenothiazine, cured antibiotic resistance and lactose fermentation of e.coli, tumour inducing ability of agrobacterium tumefaciens and nodule formation of rhizobium meliloti. plasmids of different e.coli s ... | 1992 | 1295542 |
| the early nodulin gene srenod2 from sesbania rostrata is inducible by cytokinin. | the structure and expression of the early nodulin gene enod2 from the stem-nodulated tropical legume sesbania rostrata (srenod2) was examined. genomic clones carrying the single srenod2locus were isolated and the dna sequence of the gene was determined. the srenod2 gene was found to lack introns and to encode a protein consisting primarily of a 55-fold repeat of short proline-rich oligopeptides. a putative signal sequence, which may be responsible for targeting of the enod2 protein to the cell w ... | 1992 | 1303791 |
| mutational analysis of agrobacterium tumefaciens vird2: tyrosine 29 is essential for endonuclease activity. | agrobacterium tumefaciens vird2 polypeptide, in the presence of vird1, catalyzes a site- and strand-specific nicking reaction at the t-dna border sequences. vird2 is found tightly attached to the 5' end of the nicked dna. the protein-dna complex is presumably formed via a tyrosine residue of vird2 (f. durrenberger, a. crameri, b. hohn, and z. koukolikova-nicola, proc. natl. acad. sci. usa 86:9154-9158, 1989). a mutational approach was used to study whether a tyrosine residue(s) of vird2 is requi ... | 1992 | 1309520 |
| microprojectile bombardment of plant tissues increases transformation frequency by agrobacterium tumefaciens. | bombardment of plant tissues with microprojectiles in an effective method of wounding to promote agrobacterium-mediated transformation. tobacco cv. xanthi leaves and sunflower apical meristems were wounded by microprojectile bombardment prior to application of agrobacterium tumefaciens strains containing genes within the t-dna encoding gus or nptii. stable kanamycin-resistant tobacco transformants were obtained using an nptii construct from particle/plasmid, particle-wounded/agrobacterium-treate ... | 1992 | 1310058 |
| the chloramphenicol acetyltransferase gene of tn2424: a new breed of cat. | we have sequenced the gene coding for the chloramphenicol acetyltransferase of tn2424 of plasmid nr79. this gene codes for a protein of 23,500 da, and the derived protein sequence is similar to those of the chromosomal chloramphenicol acetyltransferases of agrobacterium tumefaciens and pseudomonas aeruginosa and of unidentified open reading frames, which may encode chloramphenicol acetyltransferases, adjacent to the ermg macrolide-lincosamide-streptogramin resistance gene of bacillus sphaericus ... | 1992 | 1314803 |
| leukotriene b4 omega-oxidation by human polymorphonuclear leukocytes is inhibited by pyocyanin, a phenazine derivative produced by pseudomonas aeruginosa. | human polymorphonuclear leukocytes (pmnl) metabolize the potent chemotaxin leukotriene b4 (ltb4) by omega-oxidation to 20-hydroxyl-ltb4 and 20-carboxy-ltb4. the ability of unstimulated human pmnl to metabolize exogenous ltb4 was found to be inhibited by pyocyanin, a phenazine derivative produced by pseudomonas aeruginosa, in a dose-dependent manner. 1-hydroxyphenazine (1-ohp), a metabolite of pyocyanin, was not inhibitory under identical conditions. the initial enzymic step in the conversion of ... | 1992 | 1316878 |
| inhibition of lipopolysaccharide synthesis in agrobacterium tumefaciens and aeromonas salmonicida. | lipopolysaccharide (lps) synthesis was inhibited, new lipid a metabolites accumulated, and growth ceased, when the plant pathogen agrobacterium tumefaciens and the fish pathogen aeromonas salmonicida were treated with an antibacterial agent which specifically inhibits ctp:cmp-3-deoxy-manno-octulosonate cytidylyltransferase (cmp-kdo synthase). the new lipid a metabolites were purified by chromatography on deae-cellulose and chemically analysed. metabolites isolated from both bacterial species con ... | 1992 | 1324975 |
| [a toxicological evaluation of an agrobacterium radiobacter-based biological fertilizer]. | pathogenic properties (for warm-blooded organisms) of the industrial strain agrobacterium radiobacter (strain 204) and toxicity of biofertilizer on its base--rhizoagrin--have been studied. it is established that the studied microorganisms are avirulent, nontoxic, nontoxicogenic and may be recommended for making biopreparations. the preparation rhizoagrin is not toxic for warm-blooded animals and may be used as an alternative of chemical mineral fertilizers. | 1992 | 1331718 |
| sequence analysis of an insertion element, is1131, isolated from the nopaline-type ti plasmid of agrobacterium tumefaciens. | transferred dna (t-dna) from several nopaline-type ti plasmids of agrobacterium tumefaciens was previously shown to be variable in size due to the insertion of extra dna segments. we found an insertion sequence (named is1131) in the t-dna of the strain po22 and determined the nucleotide (nt) sequence. is1131 is 2773 bp long, contains four open reading frames, and is flanked by 12-bp perfect inverted repeats (ir). an 8-bp direct repeat was found immediately outside the ir, and represents a target ... | 1992 | 1339366 |
| bismuth subsalicylate in the treatment of h2 blocker resistant duodenal ulcers: role of helicobacter pylori. | fifty nine patients with helicobacter pylori positive duodenal ulcers that failed to heal after a six week course of treatment with h2 blockers were randomly assigned to one of the following three regimens: (i) bismuth subsalicylate, 600 mg three times daily (n = 19), (ii) ranitidine, 300 mg at night (n = 20), (iii) bismuth subsalicylate plus ranitidine (n = 20). cumulative ulcer healing rates after four and eight weeks respectively were as follows: bismuth subsalicylate 74% (14/19) and 95% (18/ ... | 1992 | 1347278 |
| expression of helenium virus s coat protein in escherichia coli, in vitro in rabbit reticulocyte lysate and transgenic tobacco. | the coat protein open reading frame (orf) sequence of helenium virus s (helvs) was cloned and expressed in e. coli, rabbit reticulocyte and transgenic tobacco. in e. coli the size of the protein was identical to that obtained for the coat protein from purified virus particles and less than that predicted for the fusion protein. this may be due to ribosome binding at a potential ribosome binding site present on the viral sequence, approximately 45 nucleotides upstream from the initiating methioni ... | 1992 | 1363991 |
| protection against detrimental effects of potyvirus infection in transgenic tobacco plants expressing the papaya ringspot virus coat protein gene. | we obtained transgenic tobacco plants expressing the papaya ringspot virus (prv) coat protein (cp) gene by transformation via agrobacterium tumefaciens. expression was effectively monitored by enzyme-linked immunosorbent assays (elisa) of crude tissue extracts. subcloned plants derived from eight original ro transformants were inoculated with potyviruses: tobacco etch (tev), potato virus y (pvy), and pepper mottle (pemv). plants that accumulated detectable levels of the prv cp showed significant ... | 1991 | 1367635 |
| microbial modification of sugars as building blocks for chemicals. | investigations on the microbial modification of sucrose to the corresponding 3-keto-derivative were carried out with resting cells of agrobacterium tumefaciens ncppb 396. this highly specific oxidation to yield the 3-keto-derivative has been analysed kinetically with varying substrate and cell mass concentrations. the formation of the corresponding 3-keto-derivative depended strongly on the reaction time and the aeration rate and was maximal at aeration rates up to 11.5 volume air/cultivation vo ... | 1992 | 1368064 |
| a dna transformation-competent arabidopsis genomic library in agrobacterium. | we have constructed a nuclear genomic library from the cruciferous plant arabidopsis thaliana ecotype columbia in a cosmid vector, plzo3, and a host organism, agrobacterium tumefaciens agl1, which can directly dna-transform the parent organism, arabidopsis. the broad host range cosmid plzo3 carries a gentamicin acetyltransferase gene as bacterial selective marker and tandem, chimeric neomycin and streptomycin phosphotransferase genes as plant selective markers. agrobacterium agl1 carries the hyp ... | 1991 | 1368724 |
| isolation and genetic analysis of an agrobacterium tumefaciens avirulent mutant with a chromosomal mutation produced by transposon mutagenesis. | a transposon 5 (tn5) insertion was introduced into the genome of a. tumefaciens (a-208 strain harboring a nopaline type ti-plasmid) using a conjugative pjb4ji plasmid containing tn5. five thousand transconjugants were assayed for virulence on carrot (daucus carota l.) disks; 54 isolates were avirulent or very attenuated. the cellular localization (plasmid or chromosome) of the tn5 insertion in those isolates were identified by southern hybridization analysis. an avirulent mutant (b-90 strain) wi ... | 1992 | 1369092 |
| phylogeny of fast-growing soybean-nodulating rhizobia support synonymy of sinorhizobium and rhizobium and assignment to rhizobium fredii. | we determined the sequences for a 260-base segment amplified by the polymerase chain reaction (corresponding to positions 44 to 337 in the escherichia coli 16s rrna sequence) from seven strains of fast-growing soybean-nodulating rhizobia (including the type strains of rhizobium fredii chemovar fredii, rhizobium fredii chemovar siensis, sinorhizobium fredii, and sinorhizobium xinjiangensis) and broad-host-range rhizobium sp. strain ngr 234. these sequences were compared with the corresponding pre ... | 1992 | 1371066 |
| increased resistance to the toxic effects of alkylating agents in tobacco expressing the e. coli dna repair gene ada. | the protein coding region of the e. coli gene ada has been transferred to tobacco plants by a leaf disc transformation procedure involving an agrobacterium tumefaciens ti plasmid. transformed plants were shown to be transgenic for the ada message and had increased levels of o6-alkylguanine dna alkyltransferase activity. the n-methyl-n-nitrosourea- or taurinechlorethylnitrosourea-induced inhibition of growth of calluses or of cells in suspension was considerably lower in ada-transformed than in n ... | 1992 | 1374848 |
| conjugative transfer functions of broad-host-range plasmid rk2 are coregulated with vegetative replication. | the kilb locus (which is unclonable in the absence of korb) of broad-host-range plasmid rk2 (60 kb) lies between the trfa operon (co-ordinates 16.4 to 18.2 kb), which encodes a protein essential for vegetative replication, and the tra2 block of conjugative transfer genes (co-ordinates 20.0 to 27.0 kb). promoter probe studies indicated that kilb is transcribed clockwise from a region containing closely spaced divergent promoters, one of which is the trfa promoter. the repression of both promoters ... | 1992 | 1376390 |
| petunia plants escape from negative selection against a transgene by silencing the foreign dna via methylation. | transgenic petunia hybrida clones harbouring the t-dna gene 2 of agrobacterium tumefaciens were used to test a strategy for the trapping of plant transposable elements. in the petunia line used, floral variegation is due to the presence of the non-autonomous transposable element dtph1 at the an1 locus. the gene 2 product converts the auxin precursor indole-3-acetamide and its analogue 1-naphthalene acetamide into the active auxins indole-3-acetic acid and 1-naphthalene acetic acid. plant cells t ... | 1992 | 1376407 |
| identification of brucella spp. by using the polymerase chain reaction. | the application of two synthetic oligonucleotides as probes and as primers in the polymerase chain reaction is presented for a specific, sensitive, and quick identification of brucella spp. the specific oligonucleotide sequences were chosen on the basis of a 16s rrna sequence alignment between brucella abortus and agrobacterium tumefaciens. | 1992 | 1377903 |
| involvement of a vitronectin-like protein in attachment of agrobacterium tumefaciens to carrot suspension culture cells. | infections of dicotyledonous plants by agrobacterium tumefaciens result in the formation of crown gall tumors. attachment of the bacteria to plant host cells is required for tumor formation. human vitronectin and antivitronectin antibodies both inhibited the binding of a. tumefaciens to carrot cells. wild-type bacteria are able to bind radioactive vitronectin; nonattaching mutants showed a reduction in the ability to bind vitronectin. the binding of biotype 1 a. tumefaciens to carrot cells or to ... | 1992 | 1381711 |
| mu-crystallin is a mammalian homologue of agrobacterium ornithine cyclodeaminase and is expressed in human retina. | mu-crystallin is the major component of the eye lens in several australian marsupials. the complete sequence of kangaroo mu-crystallin has now been obtained by cdna cloning. the predicted amino acid sequence shows similarity with ornithine cyclodeaminases encoded by the tumor-inducing (ti) plasmids of agrobacterium tumefaciens. until now, neither ornithine cyclodeaminase nor any structurally related enzymes have been observed in eukaryotes. rna analysis of kangaroo tissues shows that mu-crystall ... | 1992 | 1384048 |
| altered morphology in transgenic tobacco plants that overproduce cytokinins in specific tissues and organs. | an auxin-inducible bidirectional promoter from the soybean saur gene locus was fused to a reporter gene in one direction and a cytokinin biosynthetic gene in the opposite direction and the expression of these fused genes was examined in transgenic tobacco. the escherichia coli uida gene, which encodes the enzyme beta-glucuronidase (gus), was used as the reporter gene and the agrobacterium tumefaciens ipt gene, which encodes the enzyme isopentenyl transferase, was used as the cytokinin biosynthet ... | 1992 | 1397692 |
| construction of a chimeric viral gene expressing plum pox virus coat protein. | the capsid-encoding gene of plum pox virus (ppv) was fused with the leader sequence of the coat protein mrna (cp) of tobacco mosaic virus by a novel mutagenesis technique which involves reverse transcription of minus-strand rna [synthesized by in vitro transcription of a double-stranded (ds) cdna clone], using an ad hoc synthetic oligodeoxynucleotide as primer. the resulting cdna was rendered ds and cloned into the plasmid, pbluescribe m13+. transcription of this chimeric construction produced r ... | 1992 | 1398133 |
| the orit region of the agrobacterium tumefaciens ti plasmid ptic58 shares dna sequence identity with the transfer origins of rsf1010 and rk2/rp4 and with t-region borders. | ti plasmids of agrobacterium tumefaciens are conjugal elements whose transfer is induced by certain opines secreted from crown galls. on transmissible plasmids, dna transfer initiates within a cis-acting site, the origin of conjugal transfer, or orit. we have localized an orit on the a. tumefaciens plasmid ptic58 to a region containing the conjugal transfer loci trai and traii and acc, which is the locus encoding catabolism of the two conjugal opines, agrocinopines a and b. the smallest function ... | 1992 | 1400174 |
| mutational analysis of essential incp alpha plasmid transfer genes traf and trag and involvement of traf in phage sensitivity. | although the broad-host-range incp plasmids can vegetatively replicate in diverse gram-negative bacteria, the development of shuttle vector systems has established that the host range for incp plasmid conjugative transfer is greater than the range of bacteria that sustain incp replicons. towards understanding incp plasmid conjugation and the connection between incp conjugation and agrobacterium tumefaciens t-dna transfer to plants, two sets of mutants were generated in the larger transfer region ... | 1992 | 1400217 |
| functional roles assigned to the periplasmic, linker, and receiver domains of the agrobacterium tumefaciens vira protein. | vira and virg activate the agrobacterium tumefaciens vir regulon in response to phenolic compounds, monosaccharides, and acidity released from plant wound sites. vira contains an amino-terminal periplasmic domain and three cytoplasmic domains: a linker, a protein kinase, and a phosphoryl receiver. we constructed internal deletions of vira that truncate one or more domains and tested the ability of the resulting proteins to mediate environmentally responsive vir gene activation in vivo. the perip ... | 1992 | 1400253 |
| altered-function mutations of the transcriptional regulatory gene virg of agrobacterium tumefaciens. | three point mutations were isolated in the agrobacterium tumefaciens virg gene by screening for vir gene expression in the absence of added phenolic inducing compounds. all three mutations were localized in the predicted amino-terminal phosphoryl receiver domain of the protein. one mutant (n54d) bypasses the requirement for vira and phenolic inducers both for transcriptional activation of all tested vir promoters and for plant tumorigenesis. this mutant also activates vir gene expression efficie ... | 1992 | 1400254 |
| isolation and characterization of the aada aminoglycoside-resistance gene from salmonella choleraesuis. | the streptomycin- and spectinomycin-resistance gene of salmonella choleraesuis was cloned and its nucleotide sequence determined. the gene is 789 bases long, encoding a protein of a predicted size of 29,353 da. the gene product inactivated streptomycin and spectinomycin by an adenylation modification. it is homologous (c. 40% total identity) to streptomycin adenylyltransferase, a 3'(9)-o-nucleotidyltransferase (aad(3')(9)), which is encoded by the aada gene in escherichia coli, agrobacterium tum ... | 1992 | 1406282 |
| agroinfection as an alternative to insects for infecting plants with beet western yellows luteovirus. | beet western yellows luteovirus, like other luteoviruses, cannot be transmitted to host plants by mechanical inoculation but requires an aphid vector, a feature that has heretofore presented a serious obstacle to the study of such viruses. in this paper we describe use of agroinfection to infect hosts with beet western yellows virus without recourse to aphids. agroinfection is a procedure for introducing a plant virus into a host via agrobacterium tumefaciens harboring a ti plasmid, which can ef ... | 1992 | 1409615 |
| physical map of the vitopine ti plasmid ptis4. | within the agrobacterium vitis group the vitopine strains represent a special subclass. vitopine bacteria carry ti plasmids with little or no homology with the well-characterized t-dnas of agrobacterium tumefaciens or agrobacterium rhizogenes. the 262-kb ti plasmid of the vitopine strain s4 was cloned and mapped. homology studies with the octopine ti plasmid ptiach5, the nopaline ti plasmid ptic58, and the agropine/mannopine ri plasmid prihri identified several regions of homology. the origin of ... | 1992 | 1409971 |
| broad host range and promoter selection vectors for bacteria that interact with plants. | a plasmid vector, pgv910, and a derived cosmid, prg930, have been constructed. both contain the cole1 and pvs1 origins of replication and are stably maintained in escherichia coli, agrobacterium tumefaciens, and azorhizobium caulinodans ors571. they are compatible with commonly used incp cloning vectors, although pvs1 was classified as an incp plasmid, unable to replicate in e. coli (y. itoh, j.m. watson, d. haas, and t. leisinger, plasmid 11:206-220, 1984). promoter selection vectors were deriv ... | 1992 | 1421510 |
| the agrobacterium tumefaciens ti plasmid as a host vector system for introducing foreign dna in plant cells. 1980. | 1992 | 1422043 | |
| expression of ti plasmid genes in monocotyledonous plants infected with agrobacterium tumefaciens. 1984. | 1992 | 1422045 | |
| molecular analysis of the reca gene of agrobacterium tumefaciens c58. | the complete nucleotide sequence of the agrobacterium tumefaciens reca gene was determined. a comparison of the translated open reading frame of the gene with other known reca sequences revealed significant sequence conservation. however, unlike its escherichia coli equivalent, a. tumefaciens reca lacks the upstream 'sos box', suggesting a different mechanism of regulation for this gene. | 1992 | 1427086 |
| inhibition of tumor induction in tobacco by agrobacterium tumefaciens and nodulation induced by rhizobium meliloti in the presence of phenothiazines and structurally related compounds. | plasmids of agrobacterium tumefaciens and rhizobium meliloti carrying kanamycin resistance genes were eliminated from 1.4 to 0.2% of the growing bacterial cultures by promethazine and imipramine. as a result of plasmid elimination, the a. tumefaciens plasmidless isolate was not able to induce crown gall tumor on tobacco plants. the plasmidless r. meliloti strain failed to induce nodule formation on alfalfa plants. the efficiency of nodulation was decreased when the bacteria were grown in the pre ... | 1992 | 1444234 |
| detection and enumeration of bacteria in soil by direct dna extraction and polymerase chain reaction. | in order to develop a rapid and specific detection test for bacteria in soil, we improved a method based on the polymerase chain reaction (pcr). each step of the protocol, including direct lysis of cells, dna purification, and pcr amplification, was optimized. to increase the efficiency of lysis, a step particularly critical for some microorganisms which resist classical techniques, we used small soil samples (100 mg) and various lytic treatments, including sonication, microwave heating, and the ... | 1992 | 1444380 |
| expression of a coriander desaturase results in petroselinic acid production in transgenic tobacco. | little is known about the metabolic origin of petroselinic acid (18:1 delta 6cis), the principal fatty acid of the seed oil of most umbelliferae, araliaceae, and garryaceae species. to examine the possibility that petroselinic acid is the product of an acyl-acyl carrier protein (acp) desaturase, western blots of coriander and other umbelliferae seed extracts were probed with antibodies against the delta 9-stearoyl-acp desaturase of avocado. in these extracts, proteins of 39 and 36 kda were detec ... | 1992 | 1454797 |
| activation of a plant gene by t-dna tagging: auxin-independent growth in vitro. | a transferred dna (t-dna) tagging vector with the potential to produce dominant mutations was used with cocultured agrobacterium tumefaciens and protoplasts to tag genes involved in the action of the plant growth substance auxin. transgenic calli were selected for their ability to grow in the absence of auxin in the culture media. from one experiment, 12 calli that displayed this phenotype were recovered, of which 11 were able to regenerate into plants. in one plant studied in detail, protoplast ... | 1992 | 1455228 |
| agrobacterium tumefaciens peritonitis mimicking tuberculosis. | agrobacterium species have been previously implicated in the development of clinical disease. we report what we believe to be the first case of ascites caused by agrobacterium tumefaciens in a cirrhotic patient. since the correct diagnosis was made only after laparoscopy-guided collection of specimens from two different tissues, we suggest that agrobacterium may be an underdiagnosed pathogen in clinical situations in which tuberculosis is considered to be the cause of high-protein ascites. | 1992 | 1457664 |
| mechanism of action of cyclic beta-1,2-glucan synthetase from agrobacterium tumefaciens: competition between cyclization and elongation reactions. | we have examined some aspects of the mechanism of cyclic beta-1,2-glucan synthetase from agrobacterium tumefaciens (235-kda protein, gene product of the chvb region). the enzyme produces cyclic beta-1,2-glucans containing 17 to 23 glucose residues from udp-glucose. in the presence of added cyclic beta-1,2-glucans (> 0.5 mg/ml) (containing 17 to 23 glucose residues), the enzyme instead synthesizes larger cyclic beta-1,2-glucans containing 24 to 30 glucose residues. this is achieved by de novo syn ... | 1992 | 1459942 |
| deletion derivatives of pagk84 and their use in the analysis of agrobacterium plasmid functions. | the 47.7-kb plasmid pagk84, present in agrobacterium radiobacter strain k84, confers production of a novel, highly specific, antiagrobacterial antibiotic called agrocin 84. strain k84 is used commercially to biocontrol crown gall caused by agrocin 84-susceptible strains of agrobacterium tumefaciens. efficient biocontrol is dependent upon production of agrocin 84 by strain k84. starting with a derivative of pagk84 containing a tn5 insertion, a series of deletion derivatives of the plasmid were is ... | 1992 | 1461939 |
| translation controls the expression level of a chimaeric reporter gene. | transcriptional and translational fusions between the reading frame of the beta-d-glucuronidase gene (gusa) and the 2' as well as the 1' promoter of mannopine synthase (mas), a tr locus of agrobacterium tumefaciens, were made. the expression of these constructs was studied in the transgenic f1 offspring of independent tobacco transformants at the protein level by assaying for gus activity and western blot analysis of the gus protein and at the steady-state mrna level. in leaves, stems and roots ... | 1992 | 1463829 |
| factors influencing agrobacterium-mediated transient expression of gusa in rice. | transient expression of gus in rice (oryza sativa l.) mediated by agrobacterium tumefaciens was characterized using binary vectors containing gusa genes that express minimal (pkiwi105 and pcnl1) or no (p35s-gus-int and pcnl56) gus activity in bacteria. four-day old seedlings obtained from seeds or immature embryos of rice were cut into shoot, root, and seed remnants and inoculated with various strains of a. tumefaciens. transient gus expression events were quantitated histochemically by determin ... | 1992 | 1463839 |
| multiple copies of virg enhance the transient transformation of celery, carrot and rice tissues by agrobacterium tumefaciens. | in an effort to improve the t-dna-mediated transformation frequency of economically important crops, we investigated the possible enhancement effect of multiple copies of virg genes contained in agrobacterium tumefaciens strains upon the transient transformation of celery, carrot and rice tissues. four days after a. tumefaciens infection, we performed histochemical beta-glucuronidase (gus) assays to determine the frequency of transient transformation of calli from celery and carrot, and explants ... | 1992 | 1463842 |
| a nuclear localization signal and the c-terminal omega sequence in the agrobacterium tumefaciens vird2 endonuclease are important for tumor formation. | the t-dna portion of the agrobacterium tumefaciens tumor-inducing (ti) plasmid integrates into plant nuclear dna. direct repeats define the t-dna ends; transfer begins when the vird2 endonuclease produces a site-specific nick in the right-hand border repeat and attaches to the 5' end of the nicked strand. subsequent events generate linear single-stranded vird2-bound dna molecules that include the entire t-dna (t-strands). vird2 protein contains a nuclear localization signal (nls) near the c term ... | 1992 | 1465407 |
| characterization of a cell-free translation system from agrobacterium tumefaciens. | 1992 | 1486984 | |
| evidence that the acidic polysaccharide secreted by agrobacterium radiobacter (atcc 53271) has a seventeen glycosyl-residue repeating unit. | the extracellular anionic polysaccharide produced by the bacterium agrobacterium radiobacter (atcc 53271) contains d-galactose, d-glucose, and pyruvic acid in the molar ratio 2:15:2. analysis of the methylated polysaccharide indicated the presence of terminal, non-reducing glucosyl, 3-, 4-, 6-, 2,4-, and 4,6-linked glucosyl residues, 3-linked 4,6-o-[(s)-1-carboxyethylidene]glucosyl residues, and 3-linked galactosyl residues. partial acid hydrolysis of the methylated polysaccharide, followed by r ... | 1992 | 1499017 |
| transconjugants of agrobacterium radiobacter harbouring sym genes of rhizobium galegae can form an effective symbiosis with medicago sativa. | it is known that the rhizobium galegae genomes contain megaplasmids. the suicide vector psup2111 with nifh gene of r. meliloti was introduced into the strains ciam 0703 and ciam 0711 of r. galegae inducing effective nodules on galega orientalis plants. the formation of self-transmissible megaplasmids was observed. the megaplasmid transfer into non-nodulating r. meliloti mutants resulted in partial complementation of the nodulation defect in recipient strains though only one transconjugant showed ... | 1992 | 1499987 |
| the t-dna-linked vird2 protein contains two distinct functional nuclear localization signals. | agrobacterium tumefaciens causes neoplastic growth in plants by transferring a piece of dna, called t-dna, into the nucleus of the plant cell. the virulence protein vird2 of a. tumefaciens is tightly linked to the t-dna and is thought to direct it to the plant genome. here we show that the vird2 protein contains two nuclear localization signals that are functional both in yeast and in plant cells. one signal is located in the n-terminal part of the protein and resembles a single-cluster-type nuc ... | 1992 | 1502156 |
| construction and use of agrobacterium tumefaciens binary vectors with a. tumefaciens c58 t-dna genes. | five plant morphoregulatory genes were isolated from the agrobacterium tumefaciens ti plasmid and binary plasmid vectors for plant transformation with these genes were constructed. all vectors have a similar structure with t-dna borders, rk2 origin of replication and chimeric kanamycin resistance gene for the selection of transformed plant tissues. over twenty vectors with single and combined morphoregulatory genes were constructed and their effects after tobacco tissue transformation studied. | 1992 | 1505884 |
| transcription and autoregulation of the stabilizing functions of broad-host-range plasmid rk2 in escherichia coli, agrobacterium tumefaciens and pseudomonas aeruginosa. | the broad-host-range plasmid rk2 has been shown to encode several proteins important for its maintenance within bacterial populations of a number of gram-negative bacteria. their genes are organized into two operons: parcba and pard. these operons have been proposed to be transcribed from two divergent promoters, p-parcba and p-pard, located within a sequence of approximately 150 bases. in this report we identify and characterize the sequences required for regulated transcription from these prom ... | 1992 | 1508045 |
| factors affecting the rate of t-dna transfer from agrobacterium tumefaciens to nicotiana glauca plant cells. | different factors involved in the early steps of the t-dna transfer process were studied by using a beta-glucuronidase gene (gusa) as a reporter in nicotiana glauca leaf disc transformation experiments. the levels of transient expression of the gusa gene in leaf discs infected with several strains or vir mutants correlated well with their virulence phenotype, except for virc mutants. the rate of t-dna transfer was shown to be stimulated in the case of non-oncogenic strains by the co-transfer of ... | 1992 | 1511127 |
| constitutive expression of the beta-phaseolin gene in different tissues of transgenic alfalfa does not ensure phaseolin accumulation in non-seed tissue. | phaseolin is a glycoprotein that constitutes the major storage protein in bean seeds. the phaseolin gene promoters function in a seed-specific manner. in an attempt to understand if events following transcription of the gene also contribute to the seed-specific accumulation of the phaseolin protein, we studied the effect of substituting the constitutive camv-35s promoter for the beta-phaseolin gene promoter on expression of the phaseolin gene in different plant organs. a chimeric gene consisting ... | 1992 | 1511140 |
| at-rich promoter elements of soybean heat shock gene gmhsp17.5e bind two distinct sets of nuclear proteins in vitro. | a 33 bp double-stranded oligonucleotide homologous to two at-rich sequences located upstream (-907 to -889 and -843 to -826) to the start of transcription of heat shock gene gmhsp17.5e of soybean stimulated transcription when placed 5' to a truncated (-140) maize adh1 promoter. the chimeric promoter was assayed in vivo utilizing anaerobically stressed sunflower tumors transformed by a pti-based vector of agrobacterium tumefaciens. nuclear proteins extracted from soybean plumules were shown to bi ... | 1992 | 1511143 |
| growth inhibition and loss of virulence in cultures of agrobacterium tumefaciens treated with acetosyringone. | acetosyringone, a phenolic inducer of the virulence (vir) genes of agrobacterium tumefaciens, inhibited the growth of the nopaline-type strains t37 and c58 incubated under acidic conditions. in the course of a 6-day incubation with acetosyringone, avirulent clones were produced in different proportions by strains t37 and c58 and also by a spontaneous variant of strain c58, denominated c58f. the proportion of avirulent clones in acetosyringone-treated cultures often exceeded 50% for strains t37 a ... | 1992 | 1512200 |
| construction of a cassette enabling regulated gene expression in the presence of aromatic hydrocarbons. | a high-level expression cassette has been constructed from a tol plasmid derived from pseudomonas putida carrying all cis- and trans-acting regulatory elements necessary for transcriptional gene activation in the presence of aromatic hydrocarbons such as toluene. foreign dna can be inserted at unique kpni, saci, and ecori sites 7, 13, and 15 nucleotides downstream of a ribosome binding site. the cassette, flanked by bamhi and ecori restriction sites, was inserted into a broad-host-range vector a ... | 1992 | 1513877 |
| purification and some properties of l-fucose dehydrogenase from agrobacterium radiobacter and its application to the assay of bound-fucose in glycoconjugates. | l-fucose dehydrogenase was found in the cell extract of agrobacterium radiobacter and purified to homogeneity about 480-fold with 16% recovery. the molecular weight of the enzyme was approx. 64,000. the enzyme was active in the neutral ph range, unlike other l-fucose or d-arabinose dehydrogenases which are active only in the alkaline ph range. using this enzyme and alpha-l-fucosidase f-i of bacillus circulans (tsuji, y., yamamoto, k., tochikura, t., seno, t., ohkubo, y. and yamaguchi, h. (1990) ... | 1992 | 1525177 |
| subdomains of the octopine synthase upstream activating element direct cell-specific expression in transgenic tobacco plants. | previous work has shown that the octopine synthase (ocs) gene encoded by the agrobacterium tumefaciens ti-plasmid contains an upstream activating sequence necessary for its expression in plant cells. this sequence is composed of an essential 16-bp palindrome and flanking sequences that modulate the level of expression of the ocs promoter in transgenic tobacco calli. in this study, we have used rna gel blot analysis of rna extracted from transgenic tobacco plants to show that the octopine synthas ... | 1992 | 1525561 |
| mechanism of activation of agrobacterium virulence genes: identification of phenol-binding proteins. | agrobacterium tumefaciens initiates the expression of pathogenic genes (vir genes) in response to host-derived phenolic signals through a two-component regulatory system consisting of vira and virg. alpha-bromoacetosyringone (asbr) was developed as an inhibitor of this induction process and found to be a specific and irreversible inhibitor of vir gene induction in this pathogen. formal replacement of one of the methoxy groups of asbr with iodine gave an equally effective inhibitor that could car ... | 1992 | 1528878 |
| a defective replicase gene induces resistance to cucumber mosaic virus in transgenic tobacco plants. | nicotiana tabacum cv. turkish samsun nn plants were transformed with a modified and truncated replicase gene encoded by rna-2 of cucumber mosaic virus strain fny. the replicase gene had been modified by deleting a 94-base-pair region spanning nucleotides 1857-1950; the deletion also caused a shift in the open reading frame, resulting in a truncated translation product approximately 75% as large as the full-length protein. upon transformation via agrobacterium tumefaciens, transgenic plants were ... | 1992 | 1528890 |
| cloning and sequencing of an agrobacterium tumefaciens beta-glucosidase gene involved in modifying a vir-inducing plant signal molecule. | induction of agrobacterium tumefaciens virulence genes by plant phenolic compounds is essential for successful t-dna transfer to a host plant. in douglas fir needles, the major virulence region inducer is the glycoside coniferin (j. w. morris and r. o. morris, proc. natl. acad. sci. usa 87:3612-3618, 1990). agrobacterium strains with high beta-glucosidase activity respond to coniferin and infect douglas fir seedlings, whereas most strains with low beta-glucosidase activity fail to respond to con ... | 1992 | 1537792 |
| construction of bordetella pertussis strains that overproduce genetically inactivated pertussis toxin. | nontoxic analogs of pertussis toxin (pt), produced by in vitro mutagenesis of the tox operon, are immunogenic and protective against infection by bordetella pertussis. the moderate levels of pt production by b. pertussis, however, make it the limiting antigen in the formulation of multicomponent, acellular, recombinant whooping cough vaccines. to increase production of the highly detoxified lys9gly129 pt analog by b. pertussis, additional copies of the mutated tox operon were integrated into the ... | 1992 | 1539974 |
| agroinfection of transgenic plants leads to viable cauliflower mosaic virus by intermolecular recombination. | intermolecular reconstitution of a plant virus has been detected in whole plants in a system using a defective cauliflower mosaic virus genome and transgenic host plants containing the missing viral gene. the information for the gene vi protein of the virus was integrated into the chromosome of host brassica napus plants and leaves of these plants were inoculated with agrobacterium tumefaciens containing the complementing viral sequences. in several cases, upper leaves contained replicating vira ... | 1992 | 1546451 |
| diauxic growth of agrobacterium tumefaciens 15955 on succinate and mannopine. | diauxic growth was observed upon incubation of agrobacterium tumefaciens 15955 on a mixture of succinate and mannopine as the carbon source. diauxic growth was also observed when either fumarate or l-malate was mixed with mannopine. no diauxie was detectable when a. tumefaciens 15955 was grown on a mixture of mannopine and glucose, fructose, sucrose, or l-arabinose. preferential utilization of succinate was observed in the initial growth phase of diauxie, whereas the final growth phase occurred ... | 1992 | 1551843 |
| agrobacterium tumefaciens transfers extremely long t-dnas by a unidirectional mechanism. | during crown gall tumorigenesis, part of the agrobacterium tumefaciens tumor-inducing (ti) plasmid, the t-dna, integrates into plant dna. direct repeats define the left and right ends of the t-dna, but tumorigenesis requires only the right-hand repeat. virulence (vir) genes act in trans to mobilize the t-dna into plant cells. transfer of t-dna begins when the vird endonuclease cleaves within the right-hand border repeat. although the t-dna right-border repeat promotes t-dna transmission best in ... | 1992 | 1551847 |
| new functional assignment of the carotenogenic genes crtb and crte with constructs of these genes from erwinia species. | the role of carotenoid genes crtb and crte has been functionally assigned. these genes were cloned from erwinia into escherichia coli or agrobacterium tumefaciens. their functions were elucidated by assaying early isoprenoid enzymes involved in phytoene formation. in vitro reactions from extracts of e. coli carrying the crte gene or a complete carotenogenic gene cluster in which crtb was deleted showed an elevated conversion of farnesyl pyrophosphate (fpp) into geranylgeranyl pyrophosphate (ggpp ... | 1992 | 1555761 |
| spontaneous mutation conferring the ability to catabolize mannopine in agrobacterium tumefaciens. | two nopaline-type strains of agrobacterium tumefaciens, c58 and t37, as well as strain a136, which is a ti plasmid-cured derivative of strain c58, gave rise to spontaneous mutants that were able to grow on mannopine. the observation of mutagenesis with strain a136 demonstrated that the ability to acquire this new catabolic potential was independent of the presence of a ti plasmid. the mutants were isolated after 4 weeks of incubation on minimal medium containing mannopine as the sole carbon sour ... | 1992 | 1556082 |
| the ntra gene of agrobacterium tumefaciens: identification, cloning, and phenotype of a site-directed mutant. | a 3.6-kb ecori fragment containing the ntra gene of agrobacterium tumefaciens was cloned by using the homologous ntra gene of rhizobium meliloti as a probe. construction of an ntra mutant of a. tumefaciens by site-directed insertional mutagenesis demonstrated the requirement of the ntra gene for nitrate utilization and c4-dicarboxylate transport but not for vir gene expression or tumorigenesis. | 1992 | 1556090 |
| biolistic transformation of prokaryotes: factors that affect biolistic transformation of very small cells. | five bacterial species were transformed using particle gun-technology. no pretreatment of cells was necessary. physical conditions (helium pressure, target cell distance and gap distance) and biological conditions (cell growth phase, osmoticum concentration, and cell density) were optimized for biolistic transformation of escherichia coli and these conditions were then used to successfully transform agrobacterium tumefaciens, erwinia amylovora, erwinia stewartii and pseudomonas syringae pv. syri ... | 1992 | 1556553 |
| spatial and temporal expression patterns directed by the agrobacterium tumefaciens t-dna gene 5 promoter during somatic embryogenesis in carrot. | we have analysed the patterns of expression of a gene encoding beta-glucuronidase (gus) fused to the promoter of the agrobacterium tumefaciens t-dna gene 5 during embryogenesis in carrot, daucus carota l. gene expression was monitored by a histochemical assay of beta-glucuronidase activity. the gene 5 promoter, although of bacterial origin, conferred expression upon the marker gene in all stages of embryo development. the patterns of expression however, differed between embryos in different stag ... | 1992 | 1558941 |
| catheter-associated sepsis caused by ochrobactrum anthropi: report of a case and review of related nonfermentative bacteria. | ochrobactrum anthropi, formerly known as cdc group vd, is an oxidase-producing, gram-negative, non-lactose-fermenting bacillus that oxidizes glucose and grows readily on macconkey agar. only occasionally isolated from human clinical specimens, this organism has rarely been found to be pathogenic. we describe the first reported case of infection due to o. anthropi in a child, that of bacteremia in a 3-year-old girl undergoing chemotherapy for retinoblastoma. in addition, we review the literature ... | 1992 | 1576286 |
| self-splicing introns in trna genes of widely divergent bacteria. | the organization of eukaryotic genes into exons separated by introns has been considered as a primordial arrangement but because it does not exist in eubacterial genomes it may be that introns are relatively recent acquisitions. a self-splicing group i intron has been found in cyanobacteria at the same position of the same gene (that encoding leucyl transfer rna, uaa anticodon) as a similar group i intron of chloroplasts, which indicates that this intron predates the invasion of eukaryotic cells ... | 1992 | 1579169 |
| expression of a chimaeric heat-shock-inducible agrobacterium 6b oncogene in nicotiana rustica. | the t-6b gene of agrobacterium tumefaciens strain tm4 induces tumours on nicotiana rustica by an as yet unknown mechanism. these tumours cannot be regenerated into normal plants. to study the effect of the t-6b gene product on normal plant cells, the t-6b gene was placed under control of the drosophila melanogaster hsp70 heat-shock promoter and introduced into n. rustica. progeny of an hsp70-t-6b transformant developed into normal plants. the inducibility of the hsp70-t-6b construct was shown by ... | 1992 | 1581569 |
| the a. tumefaciens transcriptional activator occr causes a bend at a target promoter, which is partially relaxed by a plant tumor metabolite. | octopine is released from crown gall tumors as a nutrient source and a signal molecule for the plant pathogen agrobacterium tumefaciens. some or all octopine-inducible genes are regulated by a protein called occr. primer extension analysis showed that occr protein represses the occr gene and both represses and activates the occq operon, which is divergently transcribed from occr. these promoters initiate transcription 46 bp apart. this regulatory system was reconstituted in vitro using purified ... | 1992 | 1586946 |
| analysis of mutations in trfa, the replication initiation gene of the broad-host-range plasmid rk2. | plasmids with mutations in trfa, the gene encoding the replication initiation protein of the broad-host-range plasmid rk2, were isolated and characterized. mutants identified from a nitrosoguanidine bank were defective in supporting the replication of a wild-type rk2 origin in escherichia coli. most of the mutations were clustered in a region of trfa corresponding to the carboxy-terminal quarter of the trfa protein. 5' and 3' deletion mutants of trfa were also constructed. a c-terminal deletion ... | 1992 | 1597426 |
| constitutive mutations of agrobacterium tumefaciens transcriptional activator virg. | the virulence (vir) genes of agrobacterium tumefaciens ti plasmids are positively regulated by virg in conjunction with vira and plant-derived inducing molecules. a procedure that utilizes both genetic selection and a genetic screen was developed to isolate mutations in virg that led to elevated levels of vir gene expression in the absence of vira and plant phenolic inducers. mutants were isolated at a frequency of 1 in 10(7) to 10(8). substitution mutations at two positions in the virg coding r ... | 1992 | 1597431 |
| resistance to tomato spotted wilt virus infection in transgenic tobacco expressing the viral nucleocapsid gene. | a recombinant plasmid containing the entire tomato spotted with virus (tswv) nucleocapsid gene, with the exception of nucleotide encoding three n-terminal amino acids, was isolated by screening a complementary dna library, prepared against random primed viral rna, using a specific monoclonal antibody. the insert contained in plasmid ptsw1 was repaired and amplified by polymerase chain reaction, and the complete nucleocapsid protein gene was introduced into nicotiana tabacum 'samsun' by leaf disk ... | 1992 | 1600236 |
| a staphylococcal multidrug resistance gene product is a member of a new protein family. | the complete nucleotide sequence (321 bp) of smr (staphylococcal multidrug resistance), a gene coding for efflux-mediated multidrug resistance of staphylococcus aureus, was determined by using two different plasmids as dna templates. the smr gene product (identical to products of ebr and qacc/d genes) was shown to be homologous to a new family of small membrane proteins found in escherichia coli, pseudomonas aeruginosa, agrobacterium tumefaciens, and proteus vulgaris. the smr gene was subcloned ... | 1992 | 1615062 |
| heavy metals alter the electrokinetic properties of bacteria, yeasts, and clay minerals. | the electrokinetic patterns of four bacterial species (bacillus subtilis, bacillus megaterium, pseudomonas aeruginosa, and agrobacterium radiobacter), two yeasts (saccharomyces cerevisiae and candida albicans), and two clay minerals (montmorillonite and kaolinite) in the presence of the chloride salts of the heavy metals, cd, cr, cu, hg, ni, pb, and zn, and of na and mg were determined by microelectrophoresis. the cells and kaolinite were net negatively charged at ph values above their isoelectr ... | 1992 | 1622229 |
| transgenic medicinal plants: agrobacterium-mediated foreign gene transfer and production of secondary metabolites. | agrobacterium-ti/ri plasmids are natural gene vectors, by which a number of attempts have been made in genetic engineering of secondary metabolism in pharmaceutically important plants in the last few years. opines are biosynthesized by transformed crown galls and hairy roots integrated with t-dnas of ti/ri plasmids. these opines are classified into five families according to their structures and biogenesis. the production of opines is a natural example of genetic engineering of the biosynthetic ... | 1992 | 1624938 |
| the agrobacterium tumefaciens vird3 gene is not essential for tumorigenicity on plants. | genetic studies indicate that three of the four polypeptides encoded within the vird operon of the agrobacterium tumefaciens ti plasmid are essential for virulence. in order to determine whether the fourth polypeptide, vird3, has any role in virulence, complementation analysis was used. an a. tumefaciens strain, a348 delta d, which lacked the entire vird operon in the ti plasmid ptia6, was constructed. plasmids containing defined regions of the vird operon were introduced into this strain, and v ... | 1992 | 1629176 |
| molecular analysis of the lac operon encoding the binding-protein-dependent lactose transport system and beta-galactosidase in agrobacterium radiobacter. | the genes coding for the binding-protein-dependent lactose transport system and beta-galactosidase in agrobacterium radiobacter strain ar50 were cloned and partially sequenced. a novel lac operon was identified which contains genes coding for a lactose-binding protein (lace), two integral membrane proteins (lacf and lacg), an atp-binding protein (lack) and beta-galactosidase (lacz). the operon is transcribed in the order lacefgzk. the operon is controlled by an upstream regulatory region contain ... | 1992 | 1630315 |