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improved binary vectors for agrobacterium-mediated plant transformation.improved plant transformation vectors were constructed which utilize the prihri origin of replication for highly stable maintenance in agrobacterium tumefaciens, the cole1 origin of replication for high copy maintenance in escherichia coli, and a gentamycin resistance gene as a strong selectable marker for bacteria. concise t-dna elements were engineered with border sequences from the tl-dna of ptia6, the tn5 neomycin phosphotransferase gene (npt ii) expressed from either camv 35s or mannopine s ...19901966276
agrobacterium-mediated dna transfer in sugar pine.dna transfer using agrobacterium tumefaciens has been demonstrated in sugar pine, pinus lambertiana dougl. shoots derived from cytokinin-treated cotyledons formed galls after inoculation with a. tumefaciens strains containing the plasmid ptibo542. a selectable marker, neomycin phosphotransferase ii, conferring resistance to kanamycin, was transferred into sugar pine using a binary armed vector system. callus proliferated from the galls grew without hormones and in some cases, kanamycin-resistant ...19901966486
a previously unrecognized glutamine synthetase expressed in klebsiella pneumoniae from the glnt locus of rhizobium leguminosarum.using glnt dna of rhizobium meliloti as a hybridization probe we identified a r. leguminosarum biovar phaseoli (r. l. phaseoli) locus (glnt) expressing a glutamine synthetase activity in klebsiella pneumoniae. a 2.2 kb dna fragment from r. l. phaseoli was cloned to give plasmid pmw5a, which shows interspecific complementation of a k. pneumoniae glna mutant. the cloned sequence did not show cross-hybridization to glna or glnii, the genes coding for two glutamine synthetase isozymes of rhizobium s ...19901980142
specific binding of virg to the vir box requires a c-terminal domain and exhibits a minimum concentration threshold.the positive regulatory protein virg from the virulence region of the ti plasmid of agrobacterium tumefaciens was first demonstrated to possess dna-binding capabilities using chromatographically purified protein and in vitro assays (powell et al., 1989). this paper is an extension of that research and presents evidence on the in vivo dna-binding properties of virg using a transcription interference assay. virg protein bound specifically to a 'vir box' response element and repressed transcription ...19902089226
expression of a rice glutelin promoter in transgenic tobacco.a chimeric gene consisting of the 5' flanking sequences of a rice glutelin gene (gt3) linked to the chloramphenicol acetyltransferase (cat) coding segment was introduced into tobacco via agrobacterium tumefaciens-mediated transformation. cat enzyme activity could be detected in extracts from seeds as early as 8 days after flowering and obtained a maximum level at 16 days after flowering, the onset of overall protein accumulation. significant expression of cat activity in non-seed tissues occurre ...19902101310
localized transient expression of gus in leaf discs following cocultivation with agrobacterium.a chimaeric gene has been constructed that expresses beta-d-glucuronidase (gus) in transformed plant tissues, but not in bacterial cells. this gene has proved extremely useful for monitoring transformation during the period immediately following gene transfer from agrobacterium tumefaciens. gus expression was detectable 2 days after inoculation, peaked at 3-4 days and then declined; if selection was imposed expression increased again after 10-14 days. the extent of transient expression after 4 d ...19902101312
t-dna presence and opine production in tumors of picea abies (l.) karst induced by agrobacterium tumefaciens a281.the hypervirulent agrobacterium tumefaciens strain a281 formed frequent tumors (31%) on picea abies (norway spruce), an economically important tree species in swedish forests. three-month-old seedlings were inoculated and tumors were established that grew hormone-independently in culture. tumors contained agropine and mannopine/mannopinic acid as determined by acid ph paper electrophoresis. in addition, dna hybridization studies showed that the dna from these tumor lines contained sequences homo ...19902101685
functional analysis of a complex oncogene arrangement in biotype iii agrobacterium tumefaciens strains.the ubiquitous grapevine-associated octopine/cucumopine ti plasmids of biotype iii agrobacterium tumefaciens strains carry two t regions, ta and tb, with a complex oncogene arrangement. within the octopine/cucumopine group, two main strain types were identified: 'large ta' strains with a ta region resembling the tl region of the biotype i octopine strain ach5 and 'small ta' strains with a similar t region organization as the 'large ta' strains but with a large internal ta deletion. structural an ...19902101690
octopine and nopaline strains of agrobacterium tumefaciens differ in virulence; molecular characterization of the virf locus.octopine and nopaline strains of agrobacterium tumefaciens were found to differ in virulence on nicotiana glauca. this difference is due to the absence of a functional virf locus, which is necessary for efficient tumorigenesis on n. glauca, from the nopaline ti plasmids. genetic studies and dna sequence analysis of the virf locus revealed that virf embraces one open reading frame coding for a hydrophilic protein with a molecular mass of 22,437 da. transcription of virf is directed from left to r ...19902101693
characteristics of a strong promoter from figwort mosaic virus: comparison with the analogous 35s promoter from cauliflower mosaic virus and the regulated mannopine synthase promoter.a segment of dna from the genome of figwort mosaic virus (fmv) strain m3 possesses promoter activity when tested in electroporated protoplasts from, and transgenic plants of, nicotiana tabacum cv. xanthi nc. the 1.1 kb dna segment, designated the '34s' promoter, is derived from a position on the fmv genome comparable to the position on the cauliflower mosaic virus (camv) genome containing the 35s promoter. the 34s and 35s promoters show approximately 63% nucleotide homology in the tata, ccact, a ...19902102823
transformation and regeneration of the self-incompatible species nicotiana alata link & otto.a transformation and regeneration system has been developed for nicotiana alata, a plant which is being intensively studied as a model of gametophytic self-incompatibility. plantlets can be regenerated efficiently from seedling hypocotyls. kanamycin-resistant, transformed plants have been obtained by cocultivation of regenerating hypocotyls with agrobacterium tumefaciens strain lba4404 containing a binary vector. the transformation frequency was low with less than 1% of tissue explants regenerat ...19902102859
[demonstration of 3 functional domains responsible for a kinase activity in vira, a transmembrane sensory protein encoded by the ti plasmid of agrobacterium tumefaciens].high-level expression of chimeric vira genes were obtained by replacing the first codons of vira with the first codons of trpe. the fusion proteins encoded by these constructs were partially purified and one of them exhibited autokinase activity. therefore, protein phosphorylation may be an important feature of vira function. this allowed us to define the existence of three functional domains inside vira.19902105145
stereospecific abstraction of epsilon-pro-r-hydrogen of l-lysine by l-lysine epsilon-dehydrogenase from agrobacterium tumefaciens.the stereochemical aspects of the l-lysine epsilon-dehydrogenase reaction were examined with (6r)-l-[6-3h]lysine and (6s)-dl-[6-3h]lysine. when (6s)-dl-[6-3h]lysine was used as a substrate, the tritium was found in the product, delta 1-piperideine-6-carboxylate. in contrast, the radioactivity from (6r)-l-[6-3h]lysine was not retained in the product. thus, the pro-r hydrogen at the prochiral c-6 carbon of l-lysine is specifically abstracted by the enzyme: the enzyme behaves stereochemically as an ...19902110154
identification of an agrobacterium tumefaciens virulence gene inducer from the pinaceous gymnosperm pseudotsuga menziesii.inducible t-strand mobilization from the ti plasmid of agrobacterium tumefaciens to the genome of a plant host is mediated by the activation of a cascade of bacterial virulence genes. it is initiated when the bacterium senses the presence of a low molecular weight inducer secreted by the plant. although many hydroxyphenylpropanoid and phenolic compounds can activate the virulence cascade, the only native inducers that have been identified to date are acetosyringone and hydroxyacetosyringone. a n ...19902110367
sugars induce the agrobacterium virulence genes through a periplasmic binding protein and a transmembrane signal protein.phenolic plant metabolites such as acetosyringone induce transcription of the virulence (vir) genes of agrobacterium tumefaciens through the transmembrane vira protein. we report here that certain sugars induce the vir genes synergistically with phenolic inducers by way of a distinct regulatory pathway that includes vira and a chromosomally encoded virulence protein, chve. sequence comparison showed that chve is a periplasmic galactose-binding protein corresponding to the gbp1 protein isolated f ...19902118656
sugar-mediated induction of agrobacterium tumefaciens virulence genes: structural specificity and activities of monosaccharides.the virulence genes of agrobacterium tumefaciens are induced by specific plant phenolic metabolites and sugars (g. a. cangelosi, r. g. ankenbauer, and e. w. nester, proc. natl. acad. sci. usa, in press). in this report, monosaccharides, derivatives, and analogs which induce the vir regulon have been identified and the structural requirements for monosaccharide-mediated induction have been determined. pyranose sugars with equatorial hydroxyls at c-1, c-2, and c-3 displayed strong vir gene-inducin ...19902121715
a bacterial peptide acting as a plant nuclear targeting signal: the amino-terminal portion of agrobacterium vird2 protein directs a beta-galactosidase fusion protein into tobacco nuclei.agrobacterium tumefaciens is a soil bacterium capable of transferring dna to the genome of higher plants. of the virulence region-encoded proteins of the tumor-inducing (ti) plasmid of a. tumefaciens, the vird1 and vird2 proteins are essential for t-dna transfer to plant cells. these two proteins have been shown to be directly responsible for the formation of t-strands. vird2 was also shown to be firmly attached to the 5' termini of t-strands; these facts have led to its postulation as a pilot p ...19902124696
iaa synthesis and root induction with iaa genes under heat shock promoter control.we have devised a heat shock-inducible indole-3-acetic acid (iaa) synthesis system for plant cells, which is based on the iaa genes of the agrobacterium tumefaciens t-dna and the heat shock promoter hsp70 of drosophila melanogaster. two dna constructs were tested: one contains the iaam gene linked to the hsp70 promoter (hsp70-iaam) and encodes the production of indoleacetamide (iam), the other contains hsp70-iaam and the wild-type iaah gene which codes for the conversion of iam into iaa (hsp70-i ...19902129423
synthesis and self-assembly of a functional monoclonal antibody in transgenic nicotiana tabacum.immunoglobulin light and heavy chains are synthesized in mammalian cells as precursors containing a signal peptide. processing and assembling result in formation of active antibodies. chimeric genes have been made containing the coding sequence of the barley alpha-amylase signal peptide which has been fused to cdnas coding for either the mature light or the mature heavy chain of a monoclonal antibody. a plasmid was constructed linking both chimeric genes under the control of plant active promote ...19902129424
structure and function of the promoter of the carrot v-type h(+)-atpase catalytic subunit gene.we investigated the 5'-upstream region of the gene encoding the catalytic subunit of the v-type h(+)-atpase in daucus carota. a genomic sublibrary was screened with a cdna probe, and a 4-kilobase genomic clone was obtained covering the first two exons and about 3 kilobases of the 5'-upstream sequence. the intron/exon boundaries matched established consensus sequences. within 240 base pairs (bp) upstream of the initiation codon three putative tata boxes were found. ribonuclease protection and pri ...19902139875
a family of atpases involved in active partitioning of diverse bacterial plasmids.low copy-number bacterial plasmids f (the classical escherichia coli sex factor) and prophage p1 encode partitioning functions which may provide fundamental insights into the active processes which ensure that bacterial genomes are segregated to both daughter cells prior to cell division. these partitioning systems involve two proteins: para and parb. we report that incc from the broad host-range plasmid rk2 is a member of the family of para partitioning proteins and that these proteins (as well ...19902149583
homologous recombination in plant cells after agrobacterium-mediated transformation.a single amino-acid change in the acetolactate synthase (als) protein of tobacco confers resistance to the herbicide chlorsulfuron. a deleted, nonfunctional fragment from the acetolactate synthase gene, carrying the mutant site specifying chlorsulfuron resistance plus a closely linked novel restriction site marker, was cloned into a binary vector. tobacco protoplasts transformed with agrobacterium tumefaciens carrying this vector yielded chlorsulfuron-resistant colonies. dna gel blot analysis of ...19902152167
vir genes influence conjugal transfer of the ti plasmid of agrobacterium tumefaciens.mutation of the genes vira, virb, virc, and virg of the agrobacterium tumefaciens octopine-type ti plasmid ptir10 was found to cause a 100- to 10,000-fold decrease in the frequency of conjugal transfer of this plasmid between agrobacterium cells. this effect was not absolute, however, in that it occurred only during early times (18 to 24 h) of induction of the conjugal transfer apparatus by octopine. induction of these mutant agrobacterium strains by octopine for longer periods (48 to 72 h) resu ...19902155206
a chromosomal agrobacterium tumefaciens gene required for effective plant signal transduction.the vir gene products of agrobacterium tumefaciens carry out the transfer of t-dna to the plant genome. effective transcriptional induction of the vir genes by plant signal molecules is controlled by two vir gene products, vira and virg. in this study we have identified and cloned a chromosomal region which is also required for vir gene induction. transposon insertions within this region reduce induction significantly and strongly attenuate virulence, resulting in a restricted host range for inf ...19902156804
overexpression of vird1 and vird2 genes in agrobacterium tumefaciens enhances t-complex formation and plant transformation.the vird1 and vird2 proteins encoded by an inducible locus of the virulence (vir) region of the agrobacterium tumefaciens ti plasmid are required for site-specific nicking at t-dna border sites. we have determined the nucleotide sequence of a 3.6-kilobase-pair fragment carrying the vird locus from nopaline ti plasmid ptic58. in contrast to the previous report (hagiya et al., proc. natl. acad. sci. usa 82:2669-2673, 1985), we found that the first three open reading frames were capable of encoding ...19902165478
efficient transformation of agrobacterium tumefaciens by electroporation.high-voltage electroporation was used to transform agrobacterium tumefaciens strains a136 and a348, reaching the efficiency of 1-3 x 10(8) transformants/micrograms dna. transformation frequency was dependent on the electrical field strength and the pulse length. no significant reduction in transformation efficiency was observed when the transforming dna contained sites sensitive to endonuclease atuci of a. tumefaciens.19902165971
pica, a novel plant-inducible locus on the agrobacterium tumefaciens chromosome.we used the transposon mu di1681 to identify genes on the agrobacterium tumefaciens chromosome that are inducible by extracts from carrot roots. one such locus (pica, for plant inducible chromosomal), harbored by a. tumefaciens at156, was inducible 10- to 50-fold by these extracts. mutation of pica had no detectable effect upon bacterial growth or virulence under laboratory assay conditions. however, a. tumefaciens cells harboring a mutated pica locus aggregated into long "ropes" when incubated ...19902170328
enterobactin-mediated iron transport in pseudomonas aeruginosa.a pyoverdine-deficient strain of pseudomonas aeruginosa was unable to grow in an iron-deficient minimal medium in the presence of the nonmetabolizable iron chelator ethylene diamine-di(omega-hydroxyphenol acetic acid) (eddha), although addition of enterobactin to eddha-containing minimal media did restore growth of the pyoverdine-deficient p. aeruginosa. consistent with the apparent ability of enterobactin to provide iron to p. aeruginosa, enterobactin-dependent 55fe3+ uptake was observed in cel ...19902174865
evidence that modulation requires sequences downstream of the promoters of two vir-repressed genes of bordetella pertussis.gene expression in bordetella pertussis is altered by environmental signals in a process called antigenic modulation. in the presence of modulating signals, expression of several known virulence factors and outer membrane proteins is coordinately reduced. from a bank of tnphoa fusions, we have identified five genes whose expression profiles are reciprocal of those of the major virulence determinants; that is, alkaline phosphatase activity is maximal during growth in the presence of the modulator ...19902174866
excision of a ds-like maize transposable element (ac delta) in a transient assay in petunia is enhanced by a truncated coding region of the transposable element ac.the excision of a ds-like transposable element (ac delta) is mediated in trans by the transposable element ac or its derivatives in petunia protoplasts cotransfected with two plasmid dnas. excision restores the activity of the beta-glucuronidase (gus) gene that is otherwise shut off by the presence of ac delta in its leader sequence. a transient expression assay (histochemical test) is used to detect the beta-glucuronidase activity at the protoplast to detect the beta-glucuronidase activity at t ...19902177522
plant chromosome/marker gene fusion assay for study of normal and truncated t-dna integration events.during agrobacterium tumefaciens infection, the t-dna flanked by 24 bp imperfect direct repeats is transferred and stably integrated into the plant chromosome at random positions. here we measured the frequency with which a promoterless reporter gene is activated after insertion into the nicotiana tabacum sr1 genome. when adjacent to the right or left t-dna border sequences, at least 35% of the transformants express the marker gene, suggesting preferential t-dna insertion (greater than 70%) in t ...19902177527
transcriptional induction of an agrobacterium regulatory gene at tandem promoters by plant-released phenolic compounds, phosphate starvation, and acidic growth media.transcription of the virg gene of agrobacterium tumefaciens was previously shown to be expressed from two tandem promoters and to be responsive to three stimuli: plant-released phenolic compounds, phosphate starvation, and acidic media. in this report, i describe a set of deletions and other alterations of the 5' end of virg that show that the upstream promoter (p1) is necessary for induction by phenolic compounds and by phosphate starvation, whereas the downstream promoter (p2) is induced by ac ...19902185220
characteristics of the nopaline catabolic plasmid in agrobacterium strains k84 and k1026 used for biological control of crown gall disease.wild-type agrobacterium radiobacter strain 84 and its tra- derivative k1026, used for biological control of crown gall disease, each contain the plasmid patk84b. it confers incompatibility to tumor-inducing (ti) plasmids of pathogenic a. tumefaciens, thus preventing transfer of ti plasmids into k84 and k1026, and the consequent development of pathogens resistant to the specific antibiotic, agrocin 84 produced by k84 and k1026. patk84b also resembles one group of ti plasmids in its capacity for d ...19902194227
molecular characterization of the vir regulon of agrobacterium tumefaciens: complete nucleotide sequence and gene organization of the 28.63-kbp regulon cloned as a single unit.the entire vir regulon of agrobacterium tumefaciens was subcloned and the complete 28.6-kbp nucleotide sequence was determined. the regulon was cloned as a single unit into two replicons, one of which replicates at a high copy number in this bacterium, and a second which has broad-host-range features to replicate in other gram-negative bacteria. these vir region plasmids are able to confer in trans the processing and transfer activities on a second plasmid containing the t-dna. in the high copy ...19902194232
in vitro activity of ljc10,627, a new carbapenem antibiotic with high stability to dehydropeptidase i.the in vitro activity of ljc10,627, a new carbapenem, was compared with those of imipenem and ceftazidime. ljc10,627 had broad-spectrum activity against gram-positive and gram-negative clinical isolates. the mics of this compound for 90% of members of the family enterobacteriaceae tested (mic90s), including strains resistant to ceftazidime, ranged from 0.1 to 25 micrograms/ml. ljc10,627 inhibited pseudomonas aeruginosa at an mic90 of 3.13 micrograms/ml; it thus was twofold more active than imipe ...19902203313
complementation analysis of agrobacterium tumefaciens ti plasmid virb genes by use of a vir promoter expression vector: virb9, virb10, and virb11 are essential virulence genes.the virb gene products of the agrobacterium tumefaciens tumor-inducing (ti) plasmid have been proposed to mediate t-dna transport through the bacterial cell wall into plant cells. previous genetic analysis of the approximately 9.5-kilobase-pair virb operon has been limited to transposon insertion mutagenesis. due to the polarity of the transposon insertions, only the last gene in the operon, virb11, is known to provide an essential virulence function. we have now begun to assess the contribution ...19902203743
extrachromosomal homologous recombination and gene targeting in plant cells after agrobacterium mediated transformation.we determined whether t-dna molecules introduced into plant cells using agrobacterium are suitable substrates for homologous recombination. for the detection of such recombination events different mutant versions of a nptii construct were used. in a first set of experiments protoplasts of nicotiana tabacum sr1 were cocultivated with two agrobacterium tumefaciens strains. each strain contained a different t-dna, one carrying a 5' deleted nptii gene and the other a nptii gene with a 3' deletion. a ...19902209538
inhibition by agrobacterium tumefaciens and pseudomonas savastanoi of development of the hypersensitive response elicited by pseudomonas syringae pv. phaseolicola.injection into tobacco leaves of biotype 1 agrobacterium tumefaciens or of pseudomonas savastanoi inhibited the development of a visible hypersensitive response to the subsequent injection at the same site of pseudomonas syringae pv. phaseolicola. this interference with the hypersensitive response was not seen with injection of bacterial growth medium or escherichia coli cells. live a. tumefaciens cells were required for the inhibitory effect. various mutants and strains of a. tumefaciens were e ...19902211508
genetic and sequence analysis of an 8.7-kilobase pseudomonas denitrificans fragment carrying eight genes involved in transformation of precorrin-2 to cobyrinic acid.a 8.7-kilobase dna fragment carrying pseudomonas denitrificans cob genes has been sequenced. the nucleotide sequence and the genetic analysis revealed that this fragment carries eight different cob genes (cobf to cobm). six of these genes have the characteristics of translationally coupled genes. cobi has been identified as s-adenosyl-l-methionine (sam):precorrin-2 methyltransferase structural gene because the encoded protein has the same nh2 terminus and molecular weight as those of the purifie ...19902211521
mutational analysis of the virg protein, a transcriptional activator of agrobacterium tumefaciens virulence genes.the virg protein of agrobacterium tumefaciens is required in conjunction with the vira protein for transcriptional activation of the virulence (vir) genes in response to plant phenolic compounds. these proteins are members of a family of two component regulatory systems. vir genes are activated via a cascade of phosphorylation reactions involving a specific aspartic acid residue of the virg protein. we have conducted a mutational analysis of the virg protein. by mutating conserved and nonconserv ...19902211523
transgenic nicotiana debneyii expressing viral coat protein are resistant to potato virus s infection.the coat protein gene from potato virus s (pvs) was introduced into nicotiana debneyii by leaf disc transformation using agrobacterium tumefaciens. transgenic plants expressing the viral coat protein were highly resistant to subsequent infection by the me strain of pvs as indicated by an absence of symptom development and a lack of accumulation of virus in both the inoculated and upper leaves. as in reported experiments with plants expressing potato virus x coat protein, plants expressing pvs co ...19902212996
physical map and properties of a 90-mda plasmid of azospirillum brasilense sp7.homology was previously detected between the dna restriction fragments containing rhizobium meliloti nodulation genes and the 90-mda plasmid, p90, of azospirillum brasilense sp7. two dna loci from sp7 genome that complement mutations in the exopolysaccharide synthesis genes, exob and exoc, of r. meliloti were also shown to be present on the plasmid. a more detailed characterization of the plasmid was undertaken to establish its physical map and to localize the nod homologies and other specific r ...19902217570
isolation of the replication dna region from a rhizobium plasmid and examination of its potential as a replicon for rhizobiaceae cloning vectors.the dna region essential for replication and stability of a native plasmid (ptm5) from rhizobium sp. (hedysarum) has been identified and isolated within a 5.4-kb psti restriction fragment. the isolation of this region was accomplished by cloning endonuclease-restricted ptm5 dna into a cole1-type replicon and selecting the recombinant plasmids containing the ptm5 replicator (ptm5 derivative plasmids) by their ability to replicate in rhizobium. dna homology studies revealed that ptm5-like replicon ...19902217572
[uvrd-like sequences in the genome of agrobacterium tumefaciens]. 19902227394
agrobacterium rhizogenes mutants that fail to bind to plant cells.transposon insertion mutants of agrobacterium rhizogenes were screened to obtain mutant bacteria that failed to bind to carrot suspension culture cells. a light microscope binding assay was used. the bacterial isolates that were reduced in binding to carrot cells were all avirulent on bryophyllum diagremontiana leaves and on carrot root disks. the mutants did not appear to be altered in cellulose production. the composition of the medium affected the ability of the parent and mutant bacteria to ...19902228955
characterization of the virb operon of an agrobacterium tumefaciens ti plasmid: nucleotide sequence and protein analysis.the virulence regulon of the agrobacterium tumefaciens tic58 plasmid is composed of six operons, vira, virb, virg, virc, vird and vire, which direct the transfer of t-dna into plant cells. the 9.5 kbp virb operon is the largest of these operons and its entire nucleotide sequence was determined and found to contain eleven open reading frames (orfs). gene fusions of each virb orf to t7 phi 10 were made and overexpressed in escherichia coli to confirm that they encode proteins of predicted size. hy ...19902233252
[new shuttle-type vectors for cloning in escherichia coli and agrobacterium tumefaciens].the vectors capable of replication in escherichia coli and agrobacterium tumefaciens have been constructed on the basis of the plasmid pub5502. the constructed vectors pva12, pva12-2, pva12-4 contain the mini-replicon and trimethoprim resistance gene (tp) of a broad host-range plasmid r388 (incw). the pva12 vector (8.8 kb) has been constructed by insertion of a kanamycin resistance gene (km) from the plasmid puc-4k into a psti site. it possesses 7 unique restriction sites for xhoi, smai, pvui, p ...19902233784
enhancer sequences from arabidopsis thaliana obtained by library transformation of nicotiana tabacum.in this paper we report on the use of a bidirectional enhancer cloning vehicle to isolate and characterize new enhancer sequences from arabidopsis thaliana. a library of a. thaliana genomic sau3a segments was constructed in escherichia coli in the binary plasmid enhancer cloning vehicle proa97. the t-dna based vector carries abbreviated tata regions from the cauliflower mosaic virus 35s transcription unit upstream of two genes. the library was transferred via triparental mating into agrobacteriu ...19902250645
purification, cloning, and primary structure of an enantiomer-selective amidase from brevibacterium sp. strain r312: structural evidence for genetic coupling with nitrile hydratase.an enantiomer-selective amidase active on several 2-aryl and 2-aryloxy propionamides was identified and purified from brevibacterium sp. strain r312. oligonucleotide probes were designed from limited peptide sequence information and were used to clone the corresponding gene, named amda. highly significant homologies were found at the amino acid level between the deduced sequence of the enantiomer-selective amidase and the sequences of known amidases such as indoleacetamide hydrolases from pseudo ...19902254253
osmoregulation in agrobacterium tumefaciens: accumulation of a novel disaccharide is controlled by osmotic strength and glycine betaine.we have investigated the mechanism of osmotic stress adaptation (osmoregulation) in agrobacterium tumefaciens biotype i (salt-tolerant) and biotype ii (salt-sensitive) strains. using natural-abundance 13c nuclear magnetic resonance spectroscopy, we identified all organic solutes that accumulated to significant levels in osmotically stressed cultures. when stressed, biotype i strains (c58, nt1, and a348) accumulated glutamate and a novel disaccharide, beta-fructofuranosyl-alpha-mannopyranoside, c ...19902254260
agrobacterium tumefaciens t-dna gene 6b stimulates rol-induced root formation, permits growth at high auxin concentrations and increases root size.all agrobacterium tumefaciens strains studied up to now transfer an active 6b gene to plant cells. however, the role of this gene in natural tumour induction is unknown. various effects of 6b on plant cell growth have been described, but the precise mechanism by which 6b causes these effects has not been elucidated. earlier experiments indicated that the 6b gene might increase auxin sensitivity as do the a. rhizogenes rol genes. the 6b gene from tm4 (t-6b) was therefore compared with the rolb an ...19902259331
characterization of the virg binding site of agrobacterium tumefaciens.expression of agrobacterium tumefaciens virulence (vir) genes is dependent on the presence of a conserved 'vir box' sequence in their 5' nontranscribed regions. the location and number of these sequences vary considerably in different vir genes. site-directed mutagenesis was used to identify the functional vir box(es) of virb, virc and vird. for virb expression both vir box b1 and b2 are required but only the vir box b1 is absolutely essential. of the five vir boxes of virc and vird two are requ ...19902263453
vird2 gene product from the nopaline plasmid ptic58 has at least two activities required for virulence.virulence genes vird1 and vird2 are required for t-dna processing in agrobacterium tumefaciens. the regions within vird2 contributing to t-dna processing and virulence were investigated. some insertional mutations in vird2 prevented t-dna border endonucleolytic cleavage and produced an avirulent phenotype. however, a non-polar insertion immediately after bp 684 of the 1344 bp open reading frame of vird2 did not inhibit endonucleolytic cleavage but still caused a loss of virulence. this suggested ...19902263456
agrobacterium plasmids encode structurally and functionally different loci for catabolism of agrocinopine-type opines.agrobacterium tumefaciens strains c58, t37, k827 and j73, a. rhizogenes strains a4 and 15834, and a. radiobacter strain k299 were all susceptible to agrocin 84 and this sensitivity was enhanced in each case by addition of agrocinopines a and b. analysis of transconjugants showed that sensitivity of strain a4 to agrocin 84 was encoded by para4a and not by the rhizogenic plasmid, pria4. the acc region of the a. tumefaciens nopaline-type ti plasmid ptic58, contained on the recombinant plasmid pthh2 ...19902270086
identification and quantitation of corrinoid precursors of cobalamin from pseudomonas denitrificans by high-performance liquid chromatography.after initial pretreatment for removal of interfering substances, corrinoid precursors of cobalamin from cultures of pseudomonas denitrificans were separated by hplc with a gradient elution system. in this system, all the following compounds are separated in their dicyano form, and retention times are given: cobyrinic acid; cobyrinic acid a-amide; cobyrinic acid c-amide; cobyrinic acid g-amide; cobyrinic acid a,g-diamide; cobyrinic acid c,g-diamide; cobyrinic acid a,c-diamide; cobyrinic acid a,c ...19902278386
involvement of azospirillum brasilense plasmid dna in the production of indole acetic acid.indole acetic acid (iaa) production in azospirillum brasilense strain sp245 is controlled by a 85 mda plasmid naturally present in this bacterium. in the presence of l-tryptophan, anthranilic acid production and almost no iaa production occurs in a derivative strain harbouring a tn5-mob insertion in the 85 mda plasmid. agrobacterium tumefaciens strain gm19023, upon transfer of tn5-mob labelled 85 mda plasmid of a. brasilense sp245, gains the ability to produce anthranilic acid.19902283026
virg, an agrobacterium tumefaciens transcriptional activator, initiates translation at a uug codon and is a sequence-specific dna-binding protein.the agrobacterium tumefaciens ti plasmid virg locus, in conjunction with vira and acetosyringone, activates transcription of the virulence (vir) genes. insertional and deoxyoligonucleotide-directed mutagenesis studies showed that both octopine and nopaline ti plasmid virg genes initiate translation at a uug codon. virg protein initiated at this uug codon was found to be 241 amino acid residues in length and had an apparent molecular mass of 27.1 kilodaltons. a salmonella typhimurium trp-virg tra ...19902307647
biochemical characterization of avirulent exoc mutants of agrobacterium tumefaciens.the synthesis of periplasmic beta(1-2)glucan is required for crown gall tumor formation by agrobacterium tumefaciens and for effective nodulation of alfalfa by rhizobium meliloti. the exoc (psca) gene is required for this synthesis by both bacteria as well as for the synthesis of capsular polysaccharide and normal lipopolysaccharide. we tested the possibility that the pleiotropic exoc phenotype is due to a defect in the synthesis of an intermediate common to several polysaccharide biosynthetic p ...19902307661
correction: characterization of the virb operon from agrobacterium tumefaciens ti plasmid. 19902307685
binding-protein-dependent lactose transport in agrobacterium radiobacter.agrobacterium radiobacter ncib 11883 was grown in lactose-limited continuous culture at a dilution rate of 0.045/h. washed cells transported [14c]lactose and [methyl-14c]beta-d-thiogalactoside, a nonmetabolisable analog of lactose, at similar rates and with similar affinities (km for transport, less than 1 microm). transport was inhibited to various extents by the uncoupling agent carbonyl cyanide p-trifluoromethoxyphenylhydrazone, by unlabeled beta-galactosides and d-galactose, and by osmotic s ...19902318800
osmosensitivity phenotypes of agrobacterium tumefaciens mutants that lack periplasmic beta-1,2-glucan.the periplasmic cyclic beta-1,2-glucan of agrobacterium tumefaciens is believed to maintain high osmolarity in the periplasm during growth of the bacteria on low-osmotic-strength media. strains with mutations in the chva or chvb gene do not accumulate beta-1,2-glucan in their periplasm and exhibit pleiotropic phenotypes, including inability to form crown gall tumors on plants. we examined the effects of medium osmolarity to determine whether some or all of these phenotypes result from suboptimal ...19902318812
virulence genes promote conjugative transfer of the ti plasmid between agrobacterium strains.certain virulence region operons of the agrobacterium tumefaciens ti plasmid promoted conjugative ti plasmid transfer. mutations in the vir region of ptic58 inhibited conjugative plasmid transfer between a. tumefaciens strains. mutations in vira, virg, 5' virb, and vire had the greatest effect on plasmid transfer, and mutations in virc had no effect. transfer inhibition in vir mutants occurred in the presence or absence of acetosyringone.19902318813
re-examination of cellular cyclic beta-1,2-glucans of rhizobiaceae: distribution of ring sizes and degrees of glycerol-1-phosphate substitution.gel-filtration and thin layer chromatography of low molecular weight carbohydrates from culture filtrates of agrobacterium radiobacter, isolate ii, have shown, that next to the neutral beta-1,2-glucan fraction a major acidic fraction was present which was found to be glycerophosphorylated cyclic beta-1,2-glucans. re-examination of cyclic beta-1,2-glucan preparations which had been obtained by extraction of rhizobium cells with hot phenol-water also showed these acidic modified beta-1,2-glucans t ...19902321938
construction of an intron-containing marker gene: splicing of the intron in transgenic plants and its use in monitoring early events in agrobacterium-mediated plant transformation.agrobacterium tumefaciens is a commonly used tool for transforming dicotyledonous plants. the underlying mechanism of transformation however is not very well understood. one problem complicating the analysis of this mechanism is the fact that most indicator genes are already active in agrobacterium, thereby preventing the precise determination of timing and localisation of t-dna transfer to plant cells. in order to overcome this obstacle a modified prokaryotic indicator gene was constructed. the ...19902325623
expression of the agrobacterium tumefaciens chvb virulence region in azospirillum spp.inner membranes of azospirillum brasilense incubated with udp-glucose were unable to synthesize beta-(1-2) glucan and lacked the 235-kilodalton intermediate protein known to be involved in the synthesis of beta-(1-2) glucan in agrobacterium tumefaciens and rhizobium meliloti. inner membranes of a. brasilense strains carrying a cosmid containing the chromosomal virulence genes chva and chvb of agrobacterium tumefaciens formed beta-(1-2) glucan in vitro and synthesized the 235-kilodalton intermedi ...19902332404
in vitro antibacterial activities of three plants used in traditional medicine in sierra leone.the antibacterial activities of the methanol and hot and cold aqueous extracts of the leaves of aspilia africana, ficus exasperata and mareya micrantha were bioassayed against three gram-negative and three gram-positive bacterial species: aerobacter aerogenes, agrobacterium tumefaciens, bacillus subtilis, clostridium sporogenes, escherichia coli and staphylococcus aureus. the methanol and aqueous extracts of the leaves of aspilia africana and mareya micrantha and the undiluted oil of m. micranth ...19902335960
plant nuclear factor asf-1 binds to an essential region of the nopaline synthase promoter.we have characterized a tobacco nuclear factor that binds to the -118 region of the nopaline synthase (nos) promoter from the ti plasmid of agrobacterium tumefaciens. the binding site for this factor, identified by dnase i footprinting, encompasses the region from -138 to -103 of the nos promoter. this region, which contains a potential z-dna-forming sequence, was previously shown to be essential for nos promoter activity in transgenic tobacco. a synthetic 21-base pair sequence from the protecte ...19902351681
the virb operon of agrobacterium tumefaciens ptic58 encodes 11 open reading frames.agrobacterium tumefaciens genetically transforms plant cells by transferring a copy of its t-dna to the plant where it is integrated and stably maintained. in the presence of wounded plant cells this process is activated and mediated by the products of the vir genes which are grouped into six distinct loci. the largest is the virb locus spanning 9.5 kb. transposon mutagenesis studies have shown that virb gene products are required for virulence but their functions remain largely unknown. to prov ...19902370849
osmotic regulation of beta(1-2) glucan synthesis in members of the family rhizobiaceae.high osmolarity in the culture medium of growing agrobacterium tumefaciens strongly inhibited the accumulation of cellular beta(1-2) glucan. however, the enzymatic system required for the synthesis of this polysaccharide from udp-glucose was not repressed by high osmolarity. mutants of a. tumefaciens and rhizobium meliloti affected in beta(1-2) glucan synthesis were unable to grow normally in low-osmolarity media.19902376569
growth of agrobacterium tumefaciens under octopine limitation in chemostats.agrobacterium tumefaciens b6 and atcc 15955 were grown under octopine or glutamate limitation in chemostats. examination of the maximum specific growth rate (mu max) and substrate affinity (ks) for each strain indicated that strain b6 was highly inefficient in its use of octopine as either a nitrogen or carbon source compared with strain atcc 15955. examination of the yield coefficients showed that in both strains octopine was used more efficiently as a nitrogen source than as a carbon source. t ...19902383013
phosphorylation of the virg protein of agrobacterium tumefaciens by the autophosphorylated vira protein: essential role in biological activity of virg.agrobacterium tumefaciens virulence genes are induced by plant signals through the vira-virg two-component regulatory system. the vira protein is a membrane-spanning sensor molecule that possesses an autophosphorylating activity, and the virg protein is a sequence-specific dna-binding protein. in this report, we demonstrate that the virg protein is phosphorylated by the vira protein and that the phosphate is directly transferred from the phosphorylated vira molecule (phosphohistidine) to the vir ...19902394678
identification of a virb10 protein aggregate in the inner membrane of agrobacterium tumefaciens.products of the virb operon are proposed components of a membrane-associated t-dna transport apparatus in agrobacterium tumefaciens. here we identified the virb10 gene product and raised specific antiserum to the protein. while the virb10 reading frame contains two potential atg translation start sites located 32 codons apart, we found that only the downstream atg was required for efficient virb10 synthesis. cellular localization studies and analysis of translational fusions with the escherichia ...19902394684
the vira protein of agrobacterium tumefaciens is autophosphorylated and is essential for vir gene regulation.the vira and virg gene products are required for the regulation of the vir regulon on the tumor-inducing (ti) plasmid of agrobacterium tumefaciens. vira is a membrane-associated protein which is homologous to the sensor molecules of other two-component regulatory systems. we overproduced truncated vira proteins in escherichia coli by deleting different lengths of the 5'-coding region of the vira gene and placing these genes under lacz control. these proteins were purified from polyacrylamide gel ...19902404940
the regulatory virg protein specifically binds to a cis-acting regulatory sequence involved in transcriptional activation of agrobacterium tumefaciens virulence genes.virulence genes of agrobacterium tumefaciens are induced in parallel in the presence of plant phenolic compounds such as acetosyringone and the two regulatory vir genes vira and virg. in this study we identified a cis-acting regulatory sequence in the 5'-noncoding region of the vire operon that is essential for this activation. to do this, we constructed a series of deletion mutants by using exonuclease bal 31. western blot (immunoblot) analysis showed that the 70 base pairs upstream of the tran ...19902404941
corn metabolites affect growth and virulence of agrobacterium tumefaciens.homogenates of corn seedlings inhibit both growth of agrobacterium tumefaciens and induction of its ti plasmid virulence (vir) genes by acetosyringone (as). the heat-labile inhibitor has been identified as 2,4-dihydroxy-7-methoxy-2h-1,4-benzoxazin-3(4h)-one (dimboa), present in 2-week-old seedlings (b73) at a concentration of 1.5 mm or greater. a concentration of 0.3 mm dimboa is sufficient to block growth of a. tumefaciens completely for 220 hr. dimboa at 0.1 mm concentration completely inhibit ...199011607078
a nontransformable triticum monococcum monocotyledonous culture produces the potent agrobacterium vir-inducing compound ethyl ferulate.exudates of dicotyledonous plants contain specific phenolic signal molecules, such as acetosyringone, which serve as potent inducers for the expression of the virulence (vir) regulon of the phytopathogen agrobacterium tumefaciens. this induction activates the agrobacterium t-dna transfer process to initiate the genetic transformation of target plant cells. wounded and metabolically active plant cells are particularly susceptible to agrobacterium infection, and these cells specifically produce vi ...199011607083
control of expression of agrobacterium vir genes by synergistic actions of phenolic signal molecules and monosaccharides.most virulence (vir) genes of agrobacterium tumefaciens that are required for the formation of crown gall tumors are expressed in response to such plant signal molecules as acetosyringone and lignin precursors. the phenolic signals are transduced through a receptor vira protein in the inner membrane of the bacterial cell. the expression of these genes triggers the transfer of a specific dna segment, called transferred dna (t-dna), from the ti plasmid to plant cells, and its integration into thei ...199011607097
transformation of rape with agrobacterium tumeficiens-based vectors.agrobacterium tumefaciens, a soil bacterium that causes crown gall disease on a wide range of dicotyledonous plants, has been used most widely as a vehicle for gene transfer into plants (1,2). the transferred genes are stably integrated into the genomes of the transgenic plants and are transmitted to progeny as dominant mendelian traits (3,4). since the production of auxins and cytokinins coded by oncogenes on t-dna is often incompatible with normal plant development, it is often desirable to "d ...199021390616
transformation of cultured cells of chenopodium quinoa by binary vectors that carry a fragment of dna from the virulence region of ptibo542.a 15.2-kb kpni fragment from the virulence region of ptibo542, the ti plasmid harbored by agrobacterium tumefaciens strain a281, was introduced into binary vectors. the fragment contained the virb, virc and virg genes, and it is known to have the ability to increase the virulence of strains of a. tumefaciens. the strains of a. tumefaciens that carried the resulting plasmids were able to transform cells in a suspension culture of chenopodium quinoa willd cells which were not transformable by comm ...199024226938
genetic transformation of strawberry by agrobacterium tumefaciens using a leaf disk regeneration system.an efficient genetic transformation protocol has been developed for strawberry cv. redcoat using agrobacterium tumefadens. the protocol relies on a high frequency (84%) shoot regeneration system from leaf disks. the leaf disks were inoculated with a non-oncogenic agrobacterium tumefadens strain mp90 carrying a binary vector plasmid pbi121 which contains a chimeric nopaline synthase (nos) promoter driven neomycin phosphotransferase (npt ii) gene and a cauliflower mosaic virus 35s (camv35s) promot ...199024226936
agrobacterium tumefaciens-mediated transformation of pisum sativum l. using binary and cointegrate vectors.epicotyl segments and nodus expiants from etiolated seedlings of pisum sativum were transformed using agrobacterium tumefaciens strains gv 2260 (p35s gus int) and gv 3850 hpt carrying either a neomycin- or hygromycinphosphotransferase-gene as selectable markers. the transgenic character of hygromycin- or kananamycin-resistant tissue was confirmed by detection of nopaline or neomycinphosphotransferase-ii- and ß-glucuronidase activity in crude extracts of resistant tissues. up to 5 % of developing ...199024226826
transformation of cucumis sativus tissue by agrobacterium tumefaciens and the regeneration of transformed plants.cotyledons of cucumber seedlings (cucumis sativus l. cv. poinsett 76) were co-cultivated with disarmed agrobacterium strain c58z707. the agrobacterium strain contained the agrobacterium-derived binary vector plasmid pga482, its t-dna region contains a plant expressible bacterial derived neomycin phosphotransferase ii (npt ii) gene which upon transfer, genome integration, and expression in plant tissues confers resistance to the antibiotic kanamycin. after growth of inoculated cotyledon sections ...199024226818
transgenic brassica napus plants obtained by cocultivation of protoplasts with agrobacterium tumefaciens.hypocotyl protoplasts of german winter oilseed, rape (brassica napus) lines of double-low quality were transformed using agrobacterium tumefaciens harbouring pgv 3850∶1103 neo (dimer) containing chimaeric kanamycin resistance reporter genes. transformed protoplasts were regenerated to fertile and phenotypically normal plants. transformation was confirmed by kanamycin resistance, nopaline production, neomycinphosphotransferase ii activity, and southern blot hybridization. seed progeny from self-p ...199024226815
beet necrotic yellow vein virus coat protein-mediated protection in sugarbeet (beta vulgaris l.) protoplasts.transformed beta vulgaris l. suspension cultures were obtained after cocultivation of sugarbeet cells with agrobacterium tumefaciens harbouring a binary vector containing the coat protein gene of beet necrotic yellow vein virus inserted between the kanamycin resistance gene and a ß-glucuronidase reporter gene. protoplasts were isolated both from untransformed cells, and from transformed cells expressing the viral coat protein, and both were then infected with beet necrotic yellow vein virus. com ...199024226708
production of transgenic pea (pisum sativum l.) plants by agrobacterium tumefaciens - mediated gene transfer.a transformation system that allows regeneration of transgenic pea plants from calli selected for antibiotic resistance was developed. explants from axenic shoot cultures and seedling epicotyls were cocultivated with nononcogenic agrobacterium tumefaciens strains, and transformed callus could be selected on callus-inducing media containing either 15 mg/l hygromycin or 75 mg/l kanamycin. after several passages on regeneration medium, shoot organogenesis could be reproducibly induced on hygromycin ...199024220903
genetic characterization of a double-flowered tobacco plant obtained in a transformation experiment.a leaf-disk transformation experiment was performed with tobacco (nicotiana tabacum l.) using a binary vector and a strain of agrobacterium tumefaciens that carried a wild-type ti-plasmid, ptibo542. although the majority of kanamycin-resistant, transgenic plants was morphologically normal, one of the plants was double-flowered and had a slightly wavy stem and leaves whose edges were bent slightly upwards. the abnormal morphology was controlled by a single, dominant mendelian gene. young plants t ...199024220890
agrobacterium tumefaciens mediated transformation and regeneration of muskmelon plants.transgenic muskmelon (cucumis melo l.) plants were produced efficiently by inoculating cotyledon explants with agrobacterium tumefaciens strain lba4404 bearing a ti plasmid with the npt ii gene for kanaymcin resistance. after co-cultivation for three days, expiants were transferred to melon regeneration medium with kanamycin to select for transformed tissue. shoot regeneration occurred within 3-5 weeks; excised shoots were rooted on medium containing kanamycin before transferring to soil. morpho ...199024226603
meristem transformation of sunflower via agrobacterium.for transformation of sunflower (helianthus annuus l. cv. zebulon), shoot apical meristems were dissected from seeds and cocultivated with a disarmed agrobacterium tumefaciens strain harboring a binary vector carrying genes encoding gus- and nptii-activity. the influence of the media conditions, the time of cocultivation and the stage of the developing seed on shoot development and meristem transformation was analysed. transformants were selected by their ability to grow on kanamycin. transforma ...199024226429
transformation of eggplant (solanum melongena l.) using a binary agrobacterium tumefaciens vector.kanamycin resistant plants of solarium melongena l. (eggplant) cv. picentia were obtained following the cocultivation of leaf explants with agrobacterium tumefaciens. a disarmed binary vector system containing the neomycin phosphotransferase (nptii) gene as the selectable marker and chloramphenicol acetyltransferase (cat) as a reporter gene was utilized. in vitro grown plants were used as sources of explants to produce transgenic plants on selective medium containing 100 mg/l kanamycin. the tran ...199024226372
agrobacterium-mediated transformation of strawberry calli and recovery of transgenic plants.transformed calli and shoots of strawberry (fragaria × ananassa duch.) cv. redcoat were obtained using agrobacterium tumefaciens carrying plasmid pb1121. inoculated leaf explants produced transgenic calli at a frequency of 3% on selection medium containing 50 μg/ml kanamycin. twenty per cent of selected caili regenerated, giving rise to transgenic shoots. all transgenic calli and shoots expressed substantial amounts of gus and npt-ii activity. the southern blot analysis confirmed the insertion o ...199024226368
detection of bacterial chitinase activity in transformed plant tumour cells using a specific exochitinase substrate.methods for the detection of bacterial chitinase activity were compared. the soluble substrate p-nitrophenyl-ß-d-n,n diacetyl chitobiose (ndc) was more sensitive in detecting purified chitinase of serratia marcescens than assays measuring degradation of a solid chitin substrate by either radiochemical or colorimetric means. a chimaeric gene containing a s. marcescens chitinase gene under control of a cauliflower mosaic virus 35s promoter and nopaline synthase terminator sequences was constructed ...199024232928
within-population variation in susceptibility to agrobacterium tumefaciens a281 in picea abies (l.) karst.the purpose of this study was to investigate the genetic variation of susceptibility to agrobacterium within a picea abies population. tumor formation was studied in 16 open-pollinated families belonging to a central swedish population of picea abies. strain a281 of agrobacterium tumefaciens was used to infect 3-monthold seedlings in a five-block greenhouse experiment. the analysis of variance showed strong significance for the between-family variation of tumor-formation percentages, varying fro ...199024226580
genetic transformation of medicago species by agrobacterium tumefaciens and electroporation of protoplasts.shoot and leaf segments of a non-regenerable medicago sativa l. genotype were cocultivated with the "shooty" mutant of agrobacterium tumefaciens carrying the pgv 2206 plasmid. transformed callus lines were selected and regenerated on the hormone free b5 medium. southern blot analysis demonstrated integration of t-dna in to the genome of the regenerated plants.transgenic plants resistant to kanamycin were obtained by electroporation of medicago borealis protoplasts with the pga 472 plasmid dna.199024232780
production of terpenes by differentiated shoot cultures of mentha citrata transformed with agrobacterium tumefaciens t37.crown gall initiation on mentha × piperita var. citrata (ehrh.) briq. (mint) was investigated using a range of wild type and mutant strains of agrobacterium tumefaciens. axenic transformed shoot cultures of mentha 'citrata' were established on plant stems inoculated with the nopaline strain t37 of agrobacterium tumefaciens. the presence of t-dna in the transformed tissues and the absence of bacterial contamination was established by southern blot hybridisation, using (32)p labelled fragments of ...199024232681
dissimilatory ammonia production vs. denitrification in vitro and in inoculated agricultural soil samples.a dissimilatory ammonia-producing isolate identified as enterobacter amnigenus and a denitrifier identified as agrobacterium radiobacter isolated from the same soil were studied. the products of nitrate reduction in a minimal medium, enriched with glucose and containing nitrate n as the sole nitrogen source, were quantified when each of these isolates was cultured anaerobically, alone or mixed together in the presence or absence of c(2)h(2). when they were cultured together, ammonia was the prin ...199022049939
modeling growth and succinoglucan production by agrobacterium radiobacter ncib 9042 in batch cultures.wild-type agrobacterium radiobacter ncib 9042 has been cultivated in batch cultures on a synthetic medium which was adapted for growth and succinoglucan production. experiments were carried out in a 4-l stirred-tank aerated reactor. glucose, biomass, polysaccharide, protein, and inorganic- and organic-nitrogen concentrations were measured, and oxygen consumption and co(2) production rates were obtained by a gas-balance technique. nitrogen balance shows that inorganic nitrogen is entirely recover ...199118600699
interaction between meloidogyne incognita and agrobacterium tumefaciens or fusarium oxysporum f. sp. lycopersici on tomato.agrobacterium tumefaciens stimulated and fusarium oxysporum f. sp. lycopersici inhibited development and reproduction of meloidogyne incognita when applied to the opposite split root of tomato, lycopersicon esculentum cv. tropic, plants. the lowest rate of nematode reproduction occurred after 2,000 juveniles were applied and the fungus was present in the opposite split root. the effects of all three pathogens alone on the growth of roots and shoots of tomato plants were evident, but m. incognita ...199119283119
activity of the agrobacterium t-dna transfer machinery is affected by virb gene products.the orit (origin of transfer) sequence and mob (mobilization) genes of plasmid rsf1010 can functionally replace transfer dna (t-dna) borders to generate an rsf1010 intermediate transferable to plants through activities of the tumor-inducing (ti)-plasmid virulence (vir) genes of agrobacterium tumefaciens. because the ti plasmid virb gene products are hypothesized to form a membrane-localized t-dna transport apparatus, we investigated whether specific virb genes were needed for rsf1010 transfer. h ...199111607226
virf, the host-range-determining virulence gene of agrobacterium tumefaciens, affects t-dna transfer to zea mays.the monocotyledonous plant zea mays does not develop tumors after inoculation with agrobacterium tumefaciens and is thus defined as nonhost. agroinfection, agrobacterium-mediated delivery of maize streak virus, demonstrates that transferred dna (t-dna) transfer to the plant does occur. nopaline-type agrobacterium strains such as c58 are efficient in the transfer process whereas the octopine-type strain a6 is unable to transfer t-dna to maize. this phenotypic difference maps to the tumor-inducing ...199111607242
nolc, a rhizobium fredii gene involved in cultivar-specific nodulation of soybean, shares homology with a heat-shock gene.rhizobium fredii strain usda257 does not nodulate soybean (glycine max (l.) merr.) cultivar mccall. mutant 257dh5, which contains a tn5 insert in the bacterial chromosome, forms nodules on this cultivar, but acetylene-reduction activity is absent. we have sequenced the region corresponding to the site of tn5 insertion in this mutant and find that it lies within a 1176bp open reading frame that we designate nolc. nolc encodes a protein of deduced molecular weight 43564. nucleotide sequences homol ...19911646377
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