Publications

expression of alfalfa mosaic virus and tobacco rattle virus coat protein genes in transgenic tobacco plants.	using the agrobacterium tumefaciens binary vector system, a chimeric gene consisting of the cauliflower mosaic virus 35 s promoter, alfalfa mosaic virus (aimv) coat protein (cp) cistron, and the nopaline synthase polyadenylation signal was integrated into the genome of nicotiana tabacum cv. samsun nn. in 70% of the transgenic tobacco plants the chimeric mrna and its translation product could be detected. cp accumulated to levels up to 0.05% of the soluble leaf protein. the accumulation was indep ...	1987	18644569
wound expression of a potato proteinase inhibitor ii gene in transgenic tobacco plants.	a potato proteinase inhibitor ii gene was transferred into tobacco plants using agrobacterium/ti-plasmid-mediated gene transfer techniques. whereas no or little expression of the proteinase inhibitor ii gene could be detected in non-wounded leaves, high levels of proteinase inhibitor ii mrna were detected in leaves of several transgenic tobacco plants after mechanical wounding as well as after treatment of detached leaves with oligosaccharides. wounding of a leaf also led to a systemic induction ...	1987	15981327
expression and assembly of functional bacterial luciferase in plants.	the luxa and luxb structural genes of vibrio harveyi luciferase [alkanal,reduced fmn:oxygen oxidoreductase (1-hydroxylating, luminescing), ec 1.14.14.3] were introduced into a plant expression vector and transferred into tobacco and carrot cells by agrobacterium-mediated or direct dna transformation. simultaneous expression of the luxa and luxb genes was monitored by protein immunoblot analysis. luciferase-mediated light emission provided evidence for the assembly of the two protein subunits int ...	1987	16593793
genes for the catabolism and synthesis of an opine-like compound in rhizobium meliloti are closely linked and on the sym plasmid.	in alfalfa nodules induced by rhizobium meliloti strain l5-30 the compound l-3-o-methyl-scyllo-inosamine (3-o-msi) is synthesized. this compound is also catabolized specifically by this strain. its biological properties are therefore similar to the agrobacterium opines. to answer the question whether opine-like compounds ("rhizopines") play a role in a plant symbiotic interaction, we isolated the genes for the catabolism of 3-o-msi (moc genes) and for the induction of its synthesis in the nodule ...	1987	16593802
virulence genes a, g, and d mediate the double-stranded border cleavage of t-dna from the agrobacterium ti plasmid.	agrobacterium tumefaciens transfers the t-dna portion of its ti plasmid to the nuclear genome of plant cells. upon cocultivation of a. tumefaciens strain a348 with regenerating tobacco leaf protoplasts, restriction endonuclease fragments of the t-dna were generated that are consistent with double-stranded cleavage of the t-dna at the border sequences. the t-dna border cleavage was also induced by acetosyringone, a compound that induces many of the virulence genes. t-dna cleavage did not occur in ...	1987	16593820
gene tandem-mediated selection of coliphage lambda-receptive agrobacterium, pseudomonas, and rhizobium strains.	agrobacterium, pseudomonas, and rhizobium spp. have been made receptive to coliphage lambda. to achieve this, recombinant (ptroy) plasmids carrying a constitutive escherichia coli lamb gene encoding the lambda receptor and expressed from an insertion sequence 3 (is3) promoter were introduced into various bacteria. because the wild-type lambda receptor was not expressed in these bacteria, a procedure called the lamb gene tandem protocol was used to select lamb alleles that expressed the lambda re ...	1987	16593836
t-dna organization in tumor cultures and transgenic plants of the monocotyledon asparagus officinalis.	asparagus officinalis was the first monocotyledonous plant from which hormone-independent and opine-producing crown gall tissue could be isolated. we confirm by dna hybridization that tumor lines obtained after infection of this plant by agrobacterium strains harboring wild-type nopaline and octopine tumor-inducing (ti) plasmids are stably transformed and contain transferred dna (t-dna) segments identical to the t-dna found in dicotyledonous plants. we have also infected asparagus with a nononco ...	1987	16593862
expression of a complete soybean leghemoglobin gene in root nodules of transgenic lotus corniculatus.	the complete soybean leghemoglobin lbc(3) gene was transferred into the legume lotus corniculatus using an agrobacterium rhizogenes vector system. organ-specific expression of the soybean gene was observed in root nodules formed on regenerated transgenic plants after infection with rhizobium loti. the primary transcript was processed in the same way as in soybean nodules and the resulting mrna was translated into lbc(3) protein. quantitative determination of the lbc(3) protein in nodules of tran ...	1987	16593870
analysis of cis-active sequences involved in the leaf-specific expression of a potato gene in transgenic plants.	st-ls1 is a light-inducible, single-copy gene from potato that is expressed only in photosynthetic tissues. various sequences derived from the 5'-upstream region of this gene were fused to the coding region of the chloramphenicol acetyltransferase (cat) gene and to the gene 7 termination region of the transfer dna (t-dna) from the agrobacterium ti plasmid ptiach5 and transferred to tobacco using ti-plasmid vectors. after regeneration of whole plants, tissues were assayed for the expression of th ...	1987	16593893
expression of a tuber-specific storage protein in transgenic tobacco plants: demonstration of an esterase activity.	a chimaeric gene composed of the 5' upstream region of stls1, a leaf/stem specifically expressed gene from solanum tuberosum, and the rna-coding as well as the 3' downstream region of patatin, the major storage protein of potato tubers, has been transferred into tobacco plants using the agrobacterium system. the introduction of this gene led to a leaf/stem specific expression of a 42-kd large protein which immunocrossreacts with patatin antiserum. only low amounts of immunoreacting protein of sm ...	1987	16453760
phenotypic assay for excision of the maize controlling element ac in tobacco.	we describe a phenotypic assay designed to detect excision of the maize controlling element ac from a selectable marker gene, neomycin phosphotransferase ii (npt ii). an npt ii gene which expresses kanamycin resistance in tobacco cells, and contains a unique restriction enzyme site in the untranslated leader region, was constructed. ac, or a defective ac element (ac big up tri, open), was inserted into the leader region of this gene. the transposon insertions inactivated the npt ii gene as deter ...	1987	16453771
expression of alfalfa mosaic virus rna 4 in transgenic plants confers virus resistance.	agrobacterium-mediated transfer from a binary vector was used to produce transgenic nicotiana tabacum plants that expressed coat protein of the plant virus, alfalfa mosaic virus (amv). expression levels of the chimeric gene, which was under the control of the cauliflower mosaic virus 19s promoter, were determined in primary transformed plants, in the progeny from self-fertilization and in the progeny from crosses to normal tobacco. rna transcripts that were of the expected size as well as a prot ...	1987	16453779
engineering herbicide resistance in plants by expression of a detoxifying enzyme.	phosphinothricin (ppt) is a potent inhibitor of glutamine synthetase in plants and is used as a non-selective herbicide. the bar gene which confers resistance in streptomyces hygroscopicus to bialaphos, a tripeptide containing ppt, encodes a phosphinothricin acetyltransferase (pat) (see accompanying paper). the bar gene was placed under control of the 35s promoter of the cauliflower mosaic virus and transferred to plant cells using agrobacterium-mediated transformation. pat was used as a selecta ...	1987	16453789
synthesis and protein body deposition of maize 15-kd zein in transgenic tobacco seeds.	the maize 15-kd zein structural gene was placed under the regulation of french bean beta-phaseolin gene flanking regions. agrobacterium tumefaciens-mediated transformation was used to insert the chimeric phaseolin-zein gene into the tobacco genome. transgenic plants synthesized zein in a tissue-specific manner during the latter half of seed development. transcription of the chimeric gene was initiated in phaseolin-derived sequences, and was terminated within the phaseolin gene 3' flanking region ...	1987	16453803
differences in expression between two seed lectin alleles obtained from normal and lectin-deficient beans are maintained in transgenic tobacco.	using agrobacterium-mediated transformation, two genes for phytohemagglutinin-l (pha-l), the lectin seed protein of the common bean phaseolus vulgaris, were stably integrated into the tobacco genome. the two alleles for pha-l, dlec2 and pdlec2, were obtained from a normal cultivar (greensleeves) and a lectin-deficient cultivar (pinto) respectively. in the bean embryos, the expression of dlec2 is 30 times greater than the expression of pdlec2. in the dlec2-transformed tobacco, pha-l accumulated s ...	1987	16453809
cytokinin stress changes the developmental regulation of several defence-related genes in tobacco.	tobacco shoots exposed to elevated endogenous or exogenous cytokinin levels are unable to develop roots and lack apical dominance. we have isolated cdna copies of five mrna species that accumulate to elevated levels in such cytokinin-stressed shoots via differential screening of a cdna library of transgenic shoots which contain an active t-dna cytokinin gene (t-cyt gene) from agrobacterium tumefaciens. four of the cdna clones were found to correspond to plant defence-related mrnas, encoding exte ...	1987	16453810
independent and synergistic activity of rol a, b and c loci in stimulating abnormal growth in plants.	the ri plasmid a4 of agrobacterium rhizogenes contains within its t-dna genetic information able to trigger root formation in infected plants. tobacco plants regenerated from transformed roots display the hairy root (hr) syndrome. we show that dna fragments containing the rol b locus alone are able to induce root formation both in tobacco and kalanchoe tissues. the rol a and the rol c loci by themselves are also able to induce root formation in tobacco but not in kalanchoe. this capacity to indu ...	1987	16453816
population heterogeneity of agrobacterium tumefaciens in galls of populus l. from a single nursery.	this study focused on the natural crown gall infections occurring in a leuce poplar nursery. soil effects on crown gall frequency were detected, indicating that contamination was due to a resident agrobacterium tumefaciens population, which was present before seedling plantation. the crown gall frequency on poplar progenies varied from 3 to 67%, indicating the feasibility of improvement in crown gall resistance. of 129 tumor isolates, 128 were pathogenic. these isolates were of biotype 1 or 2. b ...	1987	16347314
isolation of different agrobacterium biovars from a natural oak savanna and tallgrass prairie.	populations of agrobacteria in excess of 10 cfu/g were recovered from 12 soil and root samples obtained from the allison savanna, minn., a natural oak savanna and tallgrass prairie which has never been disturbed agriculturally. of 126 strains picked randomly from selective media, 54 were identified as agrobacterium spp. biovar 2 strains predominated (35 of 54), but these strains were distributed into three phenotypically distinct subgroups. of the remaining agrobacterium strains, four were biova ...	1987	16347318
diversity among opine-utilizing bacteria: identification of coryneform isolates.	bacteria were isolated from soil and crown gall tumors by selection in minimal medium with an opine, such as succinamopine or mannopine, as the sole carbon source. the isolates were characterized for the pattern of opine utilization and identified. they were classified as mannityl opine or imino diacid utilizers and exhibited specificity of utilization similar to that described previously for agrobacterium species. a minority of isolates were gram negative and were identified as agrobacterium or ...	1987	16347383
effect of plasmid psa and of auxin on attachment of agrobacterium tumefaciens to carrot cells.	when the plasmid psa is introduced into agrobacterium tumefaciens, its presence results in the suppression of bacterial virulence. a. tumefaciens(psa) cells are virulent on bryophyllum diagremontiana only when inoculated with auxin. a. tumefaciens(psa) cells also bind to plant cells only in the presence of auxin. the effect of auxin is on the bacteria rather than on the plant cells, since the bacteria require auxin to bind to heat-killed carrot cells. bacteria containing psa and grown in the abs ...	1987	16347473
complementary methodologies to identify specific agrobacterium strains.	serological techniques and restriction enzyme cleavage patterns of total dna were used to differentiate strains of agrobacterium spp. forty-five wild-type and plasmid-cured agrobacterium strains were tested by immunodiffusion and immunofluorescence against polyclonal antisera to a crude ribosome preparation from agrobacterium strains k84, u11, b6, a323, nt1, and c58. in immunodiffusion gels, these antisera reacted only with water-phenol extracts of the homologous strain, producing a single, stra ...	1987	16347485
localization of sequences in wheat endosperm protein genes which confer tissue-specific expression in tobacco.	the developing cereal grain accumulates large quantities of proteins which are unique to the endosperm tissue. the dna sequences which determine their endosperm-specific expression have not yet been identified. in the absence of a suitable transformation-regeneration system for cereals, we have investigated whether chimaeric genes consisting of low mol. wt (lmw) and high mol. wt (hmw) glutenin gene upstream sequences coupled to the coding region of the bacterial chloramphenicol acetyl transferas ...	1987	15467781
expression of an agrobacterium ti plasmid gene involved in cytokinin biosynthesis is regulated by virulence loci and induced by plant phenolic compounds.	the nopaline-type ti plasmid t37 of agrobacterium tumefaciens carries two distinct genes that encode enzymes involved in cytokinin biosynthesis. in this report, we show that the level of expression of one of these genes was increased dramatically by culture conditions that increased the expression of ti plasmid virulence genes, including coculture with plant cells or treatment with acetosyringone, a plant phenolic compound. when this nopaline-type ti plasmid gene was introduced into agrobacteriu ...	1988	2448293
agrobacterium tumefaciens vire operon encodes a single-stranded dna-binding protein.	the virulence (vir) genes of agrobacterium tumefaciens ti plasmid are essential for transformation of plant cells. overproduction of a vire-encoded gene product in escherichia coli was achieved by construction of an operon fusion with the e. coli tryptophan (trp) operon. the vire2 gene product in e. coli partitioned into the insoluble membrane fraction. the protein was solubilized by treatment with 4 m urea at 0 degree c. dna-protein binding experiments showed that a strong single-stranded (ss) ...	1988	2452439
selective recovery of foreign gene transcripts as virus-like particles in tmv-infected transgenic tobaccos.	a short origin-of-assembly sequence (oas) located in the 30kda movement protein gene, about 1.0kb from the 3'-end of the common strain of tobacco mosaic virus (tmv) rna, nucleates encapsidation of the 6395-nucleotide-long genome by tmv coat protein in vitro, and presumably also in vivo. single-stranded rnas containing a foreign reporter gene sequence and the tmv oas at their 5' - and 3' -ends, respectively, can be synthesized in vitro from recombinant sp6-transcription plasmids and will assemble ...	1988	2453837
genetic analysis of the vire operon of the agrobacterium ti plasmid ptia6.	the vire operon of the agrobacterium tumefaciens ti plasmid ptia6 encodes at least one trans-acting protein involved in the expression of virulence. two open reading frames designated vire1 and vire2 code for polypeptides of 7 and 60 kilodaltons (kda), respectively, that can be visualized after expression in escherichia coli minicells. to determine which vire sequences are required for virulence, a strain deleted for the entire locus [strain ke1(ptia6 delta e)] was constructed and tested for the ...	1988	2832362
virulence genes, borders, and overdrive generate single-stranded t-dna molecules from the a6 ti plasmid of agrobacterium tumefaciens.	agrobacterium tumefaciens transfers the t-dna portion of its ti plasmid to the nuclear genome of plant cells. upon cocultivation of a. tumefaciens a348 with regenerating tobacco leaf protoplasts, six distinct single-stranded t-dna molecules (t strands) were generated in addition to double-stranded t-dna border cleavages which we have previously reported (k. veluthambi, r.k. jayaswal, and s.b. gelvin, proc. natl. acad. sci. usa 84:1881-1885, 1987). the t region of an octopine-type ti plasmid has ...	1988	2832367
characterization and mapping of the agrocinopine-agrocin 84 locus on the nopaline ti plasmid ptic58.	overlapping segments of ptic58 inserted into cosmid vectors were used to characterize the agrocinopine-agrocin 84 locus from the nopaline/agrocinopine a and b agrobacterium tumefaciens strain c58. all of the clones conferring agrocin 84 sensitivity on agrobacteria also conferred uptake of agrocin 84 and agrocinopines a and b. transposon tn3-hoho1 insertion mutations of one such clone were generated that simultaneously abolished agrocin 84 sensitivity and transport of agrocinopines a and b and ag ...	1988	2832379
the agrobacterium tumefaciens vire2 gene product is a single-stranded-dna-binding protein that associates with t-dna.	agrobacterium tumefaciens transfers t-dna into the plant genome by a process mediated by ti plasmid-encoded vir genes. cleavage at t-dna border sequences by the vird endonuclease generates linear, single-stranded t-dna molecules. in the work described in this report, we used electrophoretic mobility shift assays to show that the purified vire2 gene product binds to single-stranded dna. vire2 protein associates with t-dna as shown by immunoprecipitation studies with vire2-specific antiserum. the ...	1988	2836366
analysis of the complete nucleotide sequence of the agrobacterium tumefaciens virb operon.	the complete nucleotide sequence of the virb locus, from the octopine ti plasmid of agrobacterium tumefaciens strain 15955, has been determined. in the large virb-operon (9600 nucleotides) we have identified eleven open reading frames, designated virb1 to virb11. from dna sequence analysis it is proposed that nearly all virb products, i.e. virb1 to virb9, are secreted or membrane associated proteins. interestingly, both a membrane protein (virb4) and a potential cytoplasmic protein (virb11) cont ...	1988	2837739
mini-mulac transposons with broad-host-range origins of conjugal transfer and replication designed for gene regulation studies in rhizobiaceae.	novel mini-mu derivatives were constructed, carrying a truncated laczya operon fused to the terminal 117 bp of the mu s-end, for the isolation of translational lac fusions by mini-mu-mediated insertion mutagenesis. different selectable markers (chloramphenicol resistance; gentamycin resistance) were introduced to allow selection for mini-mu insertions in different replicons and bacterial strains. a mini-mulac derivative carrying the site for conjugal transfer of plasmid rp4 (orit) and the origin ...	1988	2838383
opine utilization by agrobacterium spp.: octopine-type ti plasmids encode two pathways for mannopinic acid degradation.	octopine-type strains of agrobacterium tumefaciens degrade the opine mannopinic acid through a specific pathway which involves cleavage of the molecule at the c--n bond between the amino acid and the sugar moieties. mannose was identified as a product of the reaction. this pathway was inducible by mannopinic and agropinic acids, but not by mannopine or agropine, the two other mannityl opines. the transport system for this pathway appeared to be specific for mannopinic acid. a second, nonspecific ...	1988	2838452
regulation of the virc and vird promoters of ptic58 by the ros chromosomal mutation of agrobacterium tumefaciens.	the virc and vird operons of the virulence region of the ti plasmid are highly regulated, requiring a transcriptional regulator that is encoded by virg and is activated by the product of vira and plant phenolics such as acetosyringone. full expression of virc and vird of octopine and nopaline ti plasmids is also obtained by a mutation in the ros gene of the agrobacterium tumefaciens chromosome. s1-nuclease analysis, in vitro transcription, and dnase i protection experiments with a. tumefaciens r ...	1988	2840554
transcriptional regulation of the vira and virg genes of agrobacterium tumefaciens.	we have used transcriptional and translational fusions between various vir gene promoters and the lacz gene to study the regulation of vir genes. like other vir promoters, the vira promoter was induced by acetosyringone in a vira virg-dependent fashion. in addition to being induced by acetosyringone, the virg promoter was partially induced by acidic growth conditions and by starvation for inorganic phosphate. these two conditions appeared to act synergistically. the response to low ph and to pho ...	1988	2842300
homology mapping of t-dna regions on three agrobacterium rhizogenes ri plasmids by electron microscope heteroduplex studies.	recombinant plasmids carrying segments of the agrobacterium rhizogenes t-dna regions of the three ri plasmids 1855 (tl-dna only), 8196, and 2659 were used for establishing homology maps by electron microscope examination of heteroduplexes. plasmid dna was linearized by digestion with suitable restriction endonucleases in order to generate large t-dna segments. heteroduplexes were prepared in 50% formamide and spread under standard conditions. measurements of double and single strands allowed the ...	1988	2843937
construction of a tn5 derivative encoding bioluminescence and its introduction in pseudomonas, agrobacterium and rhizobium.	a simple method based upon the use of a tn5 derivative, tn5-lux, has been devised for the introduction and stable expression of the character of bioluminescence in a variety of gram-negative bacteria. in tn5-lux, the luxab genes of vibrio harveyi encoding luciferase are inserted on a sali--bglii fragment between the kanamycin resistance (kmr) gene and the right insertion sequence. the transposon derivative was placed on a transposition suicide vehicle by in situ recombination with the tn5 suicid ...	1988	2851709
map location on agrobacterium root-inducing plasmids of homologies with the virulence region of tumor-inducing plasmids.	southern-type hybridizations were carried out in order to identify sequence homologies with the pti vir loci, on an agropine-type plasmid (prihri) and a mannopine-type plasmid (pri8196) of agrobacterium rhizogenes. the localization of the sequences hybridizing with subcloned fragments containing vir a, b, g, c, and d from ptiach5 indicated a similar linear organization of the pti vir loci and their homologies on prihri and pri8196, though no homology was detected on both pri with a 1.1-kb intern ...	1988	2852815
mobilization and transfer of azospirillum lipoferum plasmid by the tn5-mob transposon into a plasmid-free agrobacterium tumefaciens strain.	azospirillum lipoferum 4b harbors five cryptic plasmids. several suicide plasmids were used to transfer tn5-mob to a. lipoferum 4b. tn5-mob insertion mutations of this strain could be obtained at frequencies of 10(-8)-10(-7) per recipient cell. one hundred tn5-mob a. lipoferum 4b mutants were used in bacterial matings with a plasmid-free agrobacterium tumefaciens recipient strain. this is the first report of mobilization, transfer, and replication of an azospirillum plasmid in agrobacterium tume ...	1988	2852995
[deletional and insertional analysis of the antitumorigenicity of the plasmid r388 in agrobacterium tumefaciens].	the study of the plasmid r388 deletional derivatives has shown the antitumorigenicity determinant of the plasmid to be contained by the tra-operon. transposon tn5 has been used for selection of a number of insertional mutants having lost the antitumorigenic properties. the difference in the locations of tn5 inserts was found, all of the latter being localized within the tra-operon. the data obtained suggest the locus of the plasmid r388 responsible for its antitumorigenic properties to be locate ...	1988	2855090
identification of the product of an agrobacterium tumefaciens chromosomal virulence gene.	the chvb operon of agrobacterium tumefaciens is required for bacterial attachment to plant cells and for efficient crown gall tumor formation. as defined by the virulence phenotypes of mutants with transposon insertions mapping in the region, the operon was previously mapped to a 5-kilobase (kb) stretch of chromosomal dna. we report here that the operon is actually about 8.5 kb long and that it contains a 7-kb gene coding for a large membrane protein involved in the synthesis of cyclic beta-1,2- ...	1988	2856522
seed-transmissible expression of mammalian metallothionein in transgenic tobacco.	a binary plasmid was constructed to contain the mouse metallothionein c-dna, the constitutive 35s promoter from cauliflower mosaic virus, the polyadenylation signal from the pea rbcs-e9 gene and several selectable markers. the plasmid was transferred to agrobacterium tumefaciens and the leaf disc method was used to transform tobacco. callus and shoots were regenerated in the presence of kanamycin and transformed plants were obtained. southern, northern and western blot analysis demonstrated inte ...	1988	2829879
mapping of agrobacterium tumefaciens chromosomal genes affecting cellulose synthesis and bacterial attachment to host cells.	six chromosomal transposon mutations in agrobacterium tumefaciens which result in an inability to synthesize cellulose fibrils were mapped to the vicinity of trp-2 and met-6. mutations which result in an inability to attach to plant cells, attc43 and attc69, also mapped in this region, as did one tn5 mutation which caused overproduction of cellulose. another cellulose overproduction mutation mapped at a distance and was closely linked to ilv-13. the results suggest that there is a region of the ...	1988	2830241
structure and transcription analysis of the gene encoding a cellobiase from agrobacterium sp. strain atcc 21400.	the dna sequence was determined for the cloned agrobacterium sp. strain atcc 21400 beta-glucosidase gene, abg. high-resolution nuclease s1 protection studies were used to map the abg mrna 5' and 3' termini. a putative abg promoter was identified whose sequence shows similarities to the consensus promoter of escherichia coli and with the nif promoter regions of klebsiella. the abg coding sequence was 1,374 nucleotides long. the molecular weight of the enzyme, based on the predicted amino acid seq ...	1988	2826395
both positive and negative regulatory elements mediate expression of a photoregulated cab gene from nicotiana plumbaginifolia.	we have analyzed promoter regulatory elements from a photoregulated cab gene (cab-e) isolated from nicotiana plumbaginifolia. these studies have been performed by introducing chimeric gene constructs into tobacco cells via agrobacterium tumefaciens-mediated transformation. expression studies on the regenerated transgenic plants have allowed us to characterize three positive and one negative cis-acting elements that influence photoregulated expression of the cab-e gene. within the upstream sequen ...	1988	2901343
the ndva gene product of rhizobium meliloti is required for beta-(1----2)glucan production and has homology to the atp-binding export protein hlyb.	the ndva locus of rhizobium meliloti is homologous to and can substitute for the chva locus of agrobacterium tumefaciens. we have previously shown that an ndva mutant exhibited reduced motility and formed small, white, empty nodules on alfalfa roots. here we show that this ndva mutant is defective in the production of the cyclic extracellular polysaccharide beta-(1----2)glucan, even though a 235,000-dalton protein intermediate, known to be involved in the synthesis of this molecule, is present a ...	1988	3042754
transfer of the ti plasmid from agrobacterium tumefaciens into escherichia coli cells.	we have screened strains of agrobacterium tumefaciens for spontaneous mutants showing constitutive transfer of the nopaline ti plasmid ptic58 during conjugation. the ti plasmid derivatives obtained could be transferred not only to a. tumefaciens but also to e. coli cells. the ti plasmid cannot survive as a freely replicating plasmid in e. coli, but it can occasionally integrate into the e. coli chromosome. however, insertion in tandem of plasmids carrying fd replication origins (pfd plasmids) in ...	1988	3049936
bidirectional transfer from a 24 bp border repeat of agrobacterium tumefaciens.	t-region transfer from wild-type agrobacterium strains is thought to be an orientated process, starting at the right border repeat and terminating at the left border repeat of the t-region. here we demonstrate that a right border repeat in the inverted orientation relative to the onc-genes can also mediate transfer of the t-region to the plant cell, although with lower efficiency as a border repeat in the native orientation. transfer mediated by an inverted right border repeat is stimulated by t ...	1988	3057440
effect of agrobacterium tumefaciens lipopolysaccharide on hemolytic complement system.		1988	3058583
specialized binary vector for plant transformation: expression of the arabidopsis thaliana ahas gene in nicotiana tabacum.	we constructed a cosmid vector, poca18, designed for transferring plant genomic libraries from agrobacterium tumefaciens to plants. clones from a genomic library of arabidopsis thaliana dna in poca 18 were propagated stably in both escherichia coli and a. tumefaciens. clones from the poca18 a. thaliana library were used to construct transgenic nicotiana tabacum plants; the dna inserts were transferred intact in 10 out of 16 transgenic n. tabacum plants examined but were partially deleted in six ...	1988	3060849
basic processes underlying agrobacterium-mediated dna transfer to plant cells.		1988	3071244
use of agrobacterium radiobacter in agricultural ecosystems.	agrobacterium tumefaciens is a soil inhabitant that infects many dicotyledonous plants, causing crown gall disease. the success of agrobacterium radiobacter k84 to control this disease in agroecosystems throughout the world has been impressive. this review describes the attributes of k84, its mechanism of control, its failures, and other alternative biocontrol agents.	1988	3079224
escherichia coli lacz gene as a biochemical and histochemical marker in plant cells.	several lacz chimeric genes were constructed by fusing the truncated lacz sequence of escherichia coli to n-terminal sequences of few other genes. promoters used to direct expression of the chimeric genes were the promoter for 35s rna of cauliflower mosaic virus (p35s) as well as those of the small subunit gene of ribulose bisphosphate carboxylase and the octopine synthase gene. these constructs were introduced into tobacco cells using a ti plasmid of agrobacterium tumefaciens, and beta-galactos ...	1988	3138164
differentiation of some gram-negative glucose nonfermenting bacteria using miniaturized carbon sources assimilation tests.	in water and soil the gram-negative nonfermenting bacteria play an important role in the biological mineralization process. to improve the methods for species differentiation of these heterogenous bacterial group, a total of 481 reference strains of gram-negative glucose nonfermenting bacteria belonging to the genera pseudomonas, alcaligenes, bordetella, agrobacterium, moraxella, acinetobacter, flavobacterium and some cdc groups have been investigated for their ability to utilize 42 different ca ...	1988	3142164
role of sublethal injury in decline of bacterial populations in lake water.	following their addition to lake water, the populations of escherichia coli and of antibiotic-resistant strains of pseudomonas fluorescens, agrobacterium tumefaciens, micrococcus flavus, rhizobium meliloti, and klebsiella pneumoniae declined rapidly, as determined by counting on media containing antibacterial compounds. the estimates of population sizes were occasionally higher if procedures were used that permitted possible resuscitation of injured cells. no resuscitation procedure yielded cons ...	1988	3145714
evidence for a role of a vicinal dithiol in the transport of gamma-butyrobetaine in agrobacterium sp.	an agrobacterium sp. isolated from soil is able to use gamma-butyrobetaine as its sole source of carbon and nitrogen. the involvement of thiol groups for active transport of gamma-butyrobetaine was investigated by use of the thiol alkylating reagent n-ethylmaleimide (nem) and the dithiol specific reagent phenylarsine oxide (pao). both reagents strongly inhibited gamma-butyrobetaine uptake, but also induced the release of the accumulated substrate, suggesting that the transport system either cont ...	1988	3148329
inducible expression of cytokinin biosynthesis in agrobacterium tumefaciens by plant phenolics.	nopaline strains of agrobacterium tumefaciens contain a gene, tzs, that encodes a cytokinin biosynthetic prenyl transferase. the gene is located adjacent to the ti plasmid virulence region and is constitutively expressed at low levels. as a result, bacteria containing tzs secrete low levels of zeatin into the medium. we find zeatin secretion to be induced more than 100-fold by acetosyringone, one of a number of naturally occurring phenolics produced by plants in response to wounding. induction w ...	1988	2980282
agrobacterium-mediated infectivity of cloned digitaria streak virus dna.	a monomeric clone of double-stranded dna synthesized in vitro dna of the geminivirus digitaria streak (dsv) was subcloned as a tandem dimeric unit into a binary vector of agrobacterium tumefaciens, creating a plasmid pds2. inoculation of digitaria sanguinalis with a. tumefaciens carrying pds2 resulted in viral infection. the symptoms, virus particles, and dna forms obtained were indistinguishable from those of a natural dsv infection of d. sanguinalis. inoculations have also induced infections i ...	1988	3341112
a case of septicaemia caused by agrobacterium radiobacter.		1988	3351321
expression of alfalfa mosaic virus cdna1 and 2 in transgenic tobacco plants.	chimeric genes composed of dna complementary to alfalfa mosaic virus (aimv) rnas 1 or 2, the camv 35 s promoter, and the nos polyadenylation signal were transferred to the genome of nicotiana tabacum cv. samsun nn by means of the agrobacterium tumefaciens transformation system. transformants contained intact copies of the viral genes and accumulated transcripts of approximately the size predicted from the cloning procedure. using antisera raised against synthetic peptides corresponding to the c- ...	1988	3354206
structure of the octopine synthase upstream activator sequence.	we have identified a transcriptional activating element within the 5' flanking sequence of the agrobacterium tumefaciens octopine synthase (ocs) gene that is necessary for ocs expression in transformed tobacco calli. this element is located between 333 and 116 base pairs upstream from the transcription initiation site and functions independent of orientation when placed upstream of the ocs gene. it does not function in either orientation when placed downstream of the gene, nor can it activate it ...	1988	3357881
scanning electron microscope studies of agrobacterium tumefaciens attachment to zea mays, gladiolus sp., and triticum aestivum.	scanning electron microscope studies demonstrated that cells of agrobacterium tumefaciens strains attach to cells on the cut surfaces of corn and wheat seedlings and to gladiolus disks. bacterial cells attached to these monocots in the same manner as they attached to the dicots tested. of the strains tested, a66 and t37 covered more of the cut surfaces of these monocots in a nonrandom fashion than did cells of other isolates. these bacteria attached to cells of intact monocotyledonous plants and ...	1988	3360748
studies on the pharmacological activity of amazonian euphorbiaceae.	plant material from 34 amazonian species of the family euphorbiaceae were collected and extracts prepared. sixteen of these species have a documented use as a medicinal agent. the extracts were tested for their ability to inhibit the growth of the bacteria, escherichia coli and staphylococcus aureus; the yeasts, saccharomyces cerevisiae and candida albicans; the dermatophytic fungi, microsporum canis, microsporum fulvum, microsporum gypseum and trichophyton gallinae; the viruses, sindbis virus a ...	1988	3374150
chemotaxis of rhizobium meliloti to the plant flavone luteolin requires functional nodulation genes.	luteolin is a phenolic compound from plants that acts as a potent and specific inducer of nodabc gene expression in rhizobium meliloti. we have found that r. meliloti rcr2011 exhibits positive chemotaxis towards luteolin. a maximum chemotactic response was observed at 10(-8) m. two closely related flavonoids, naringenin and apigenin, were not chemoattractants. the presence of naringenin but not apigenin abolished chemotaxis of r. meliloti towards luteolin. a large deletion in the nif-nod region ...	1988	3384804
vira and virg are the ti-plasmid functions required for chemotaxis of agrobacterium tumefaciens towards acetosyringone.	octopine and nopaline ti-plasmids confer upon agrobacterium tumefaciens c58c1 the ability to respond chemotactically to the vir-inducing phenolic wound exudate, acetosyringone. a. tumefaciens c58c1 containing ti-plasmids with tn5 insertions in virb, c, d or e exhibited marked chemotaxis towards acetosyringone. however, ti-plasmids with mutations in vira or virg were unable to confer the responsive phenotype. of the cosmid clones pvk219 (virab) pvk221 (virbgc) pvk225 (virgcde) and pvk257 (virabgc ...	1988	3398775
association of the vird2 protein with the 5' end of t strands in agrobacterium tumefaciens.	the soil bacterium agrobacterium tumefaciens can incite tumors in many dicotyledonous plants by transferring a portion (t-dna) of its ti plasmid into susceptible plant cells. the t-dna is flanked by border sequences that serve as recognition sites for specific cleavage by an endonuclease that comprises two vird-encoded proteins (vird1 and vird2). after cleavage, both double-stranded, nicked t-dna molecules and single-stranded t-dna molecules (t strands) were present. we have determined that a pr ...	1988	3403506
recognition of individual strains of fast-growing rhizobia by using profiles of membrane proteins and lipopolysaccharides.	membrane protein and lipopolysaccharide profiles of rhizobium leguminosarum (biovars viciae, trifolii, and phaseoli), r. meliloti, and agrobacterium tumefaciens strains were analyzed and compared by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. differences in one or both profiles allowed us to distinguish all 18 r. leguminosarum strains tested in this study from each other.	1988	3403513
ti plasmid-specified chemotaxis of agrobacterium tumefaciens c58c1 toward vir-inducing phenolic compounds and soluble factors from monocotyledonous and dicotyledonous plants.	twelve phenolic compounds with related structures were analyzed for their ability to act as chemoattractants for agrobacterium tumefaciens c58c1 and as inducers of the ti plasmid virulence operons. the results divided the phenolic compounds into three groups: compounds that act as strong vir inducers and are chemoattractants for a. tumefaciens c58c1 harboring the nopaline ti plasmid pdub1003 delta 31, but not the isogenic cured strain; compounds that are at best weak vir inducers and are weak ch ...	1988	3410827
right-hand border regions of octopine t-dna are recognized by rna polymerase of agrobacterium as well as by vird1 and vird2 proteins.	the t-dna of octopine ti plasmid of agrobacterium tumefaciens contains tl- and tr-dna regions each bounded by 25 base-pair-repeats (designated a, b, c and d from left to right). short dna segments containing the borders b, c and d were found to function as promoter when placed in the rightward orientation upstream of promoter-less lacz. promoter consensus sequence of agrobacterium were found within these border repeats and in their adjacent regions. the expression of lacz was low when the segmen ...	1988	3412897
expression of nodule-specific genes in alfalfa root nodules blocked at an early stage of development.	to help dissect the molecular basis of the rhizobium-legume symbiosis, we used in vitro translation and northern blot analysis of nodule rna to examine alfalfa-specific genes (nodulins) expressed in two types of developmentally defective root nodules elicited by rhizobium meliloti. fix- nodules were elicited by r. meliloti nif mutants; these nodules were invaded by rhizobia and contained differentiated bacteroids. 'empty' nodules were elicited by r. meliloti exo and ndv mutants and by agrobacter ...	1988	3417147
vir box sequences in agrobacterium tumefaciens ptic58 and a6.		1988	3419938
relative strengths of the 35s cauliflower mosaic virus, 1', 2', and nopaline synthase promoters in transformed tobacco sugarbeet and oilseed rape callus tissue.	the 35s promoter of cauliflower mosaic virus and promoters from the nopaline synthase, 1' and 2' genes of agrobacterium tumefaciens t-dna were fused to the bacterial octopine synthase and chitinase gene coding regions. these chimaeric gene constructions were introduced into tobacco, sugarbeet and oilseed rape cells and their relative levels of expression measured by primer extension analysis of rna isolated from pooled populations of stably transformed calli. in tobacco callus, the 35s promoter ...	1988	3163765
rola locus of the ri plasmid directs developmental abnormalities in transgenic tobacco plants.	plants containing the left t-dna (tl) of agrobacterium rhizogenes show a variety of developmental abnormalities that include severely wrinkled leaves, loss of apical dominance, reduced geotropism of roots, reduced internode distances, and floral hyperstyly. the tl-dna also affects the morphology of tumor tissue at the site of inoculation on kalanchoe diagremontiana leaves. single mutations at four loci of the tl-dna (rola, rolb, rolc, and rold) are known to affect tumor morphology on k. diagremo ...	1988	3166443
influence of flanking sequences on variability in expression levels of an introduced gene in transgenic tobacco plants.	the petunia rbcs gene ssu301 was introduced into tobacco using agrobacterium tumefaciens-mediated transformation. the time at which rbcs expression was maximal after transfer of the tobacco plants to the greenhouse was determined. the expression level of the ssu301 gene varied up to 9 fold between individual tobacco plants which had been standardized physiologically as much as possible. the presence of adjacent puc plasmid sequences did not affect the expression of the ssu301 gene. in an attempt ...	1988	3174450
role of iron in the enhancement by agrobacterium tumefaciens infection in mice.	microorganisms require iron for their growth and usually compete with their host for available iron from the system. iron supplementation to host causes an increase of available iron both to host and to potential microbial invaders and favours the latter more than the former as the bacteria release siderophores which are responsible for iron transport mechanism. in view of this observation a study was done to deal with the distribution of storage and injected iron given as an overload within a p ...	1988	3181831
purification and properties of the gamma-butyrobetaine-binding protein from an agrobacterium sp.	a binding protein for gamma-butyrobetaine was purified from osmotic shock fluid of an agrobacterium sp. it was a monomeric protein with an apparent molecular weight of 52,000 or 53,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration, respectively. the isoelectric point was 4.3, as determined by isoelectric focusing. amino acid analysis of the protein showed that asx and glx were predominant components and that the protein contained no cysteine. the d ...	1988	3182728
organization and characterization of the vircd genes from agrobacterium rhizogenes.	we have precisely localized virulent (vir) genes of the hairy root-inducing plasmid pria4b on the basis of sequence similarity with the tumor-inducing plasmid ptia6nc, and shown that the overall organizations of vir genes in both plasmids are fairly analogous, although sizes and spacer lengths in some genes differ from each other. among the vir genes thus mapped, the virc and vird loci were characterized in detail. transposon insertions in vird led to loss of tumorigenicity on kalanchoe stems an ...	1988	3185501
storage of competent cells for agrobacterium transformation.		1988	3186459
role of the overdrive sequence in t-dna border cleavage in agrobacterium.	the t-dna of the ti plasmid of agrobacterium is flanked by 25-base-pair imperfect direct repeats that are required in cis for transfer to the genome of the plant host. another sequence, designated overdrive, is located adjacent to the right-border repeats and functions in cis to enhance tumor formation. we have examined the effect of the overdrive sequence on the early steps in t-dna processing. we report here that overdrive greatly enhances cleavage by the site-specific endonuclease in agrobact ...	1988	3186745
glycine betaine allows enhanced induction of the agrobacterium tumefaciens vir genes by acetosyringone at low ph.	we established growth conditions for efficient induction of the vir genes of agrobacterium tumefaciens by acetosyringone. optimal induction was attained at a ph below 5.2 in an ab minimal medium-derived high-osmotic-strength medium containing glycine betaine. this natural osmoprotectant accelerated the adaptation of the bacteria to these conditions. we established the kinetics of induction for virb, vird, vire, and virg by using lacz fusions, and we found that the virb mutant strain could not ad ...	1988	3192516
vir-induced recombination in agrobacterium. physical characterization of precise and imprecise t-circle formation.	induction of ti plasmid virulence (vir) gene expression during the early stages of plant cell transformation by agrobacterium tumefaciens initiates the generation of several t-dna-associated molecular events: (1) site-specific nicks at t-dna border sequences (border nicks); (2) free, unipolar, linear, single-stranded t-dna copies (t-strands); and (3) double-stranded, circular t-dna molecules (t-circles). the first two t-dna products have been detected in a. tumefaciens, while t-circles have only ...	1988	3199438
growth dependent enzymatic profiles of some gram-negative nonfermentative bacteria of clinical significance.	a total of 734 strains of gram-negative nonfermentative bacteria (46 species and biochemically defined groups) of the genera pseudomonas, alcaligenes, bordetella, moraxella, acinetobacter, agrobacterium, and flavobacterium were investigated for their ability to hydrolyze 25 different chromogenic substrates. all tests were carried out in growth-stimulating media. results were read photometrically and evaluated automatically following a 24-h incubation. many of the 46 different species and biochem ...	1988	3223128
studies on the toxicity of agrobacterium tumefaciens in mice.		1988	3235104
nucleotide sequence of the phosphinothricin n-acetyltransferase gene from streptomyces viridochromogenes tü494 and its expression in nicotiana tabacum.	the phosphinothricin (pt) n-acetyltransferase gene (pat) of streptomyces viridochromogenes tü494 is located on a 0.8-kb bglii fragment [strauch et al., gene 63 (1988) 65-74]. by sequencing a 1.3-kb bglii-sstii fragment, an open reading frame representing the pat gene was found. it encodes a polypeptide of 183 amino acids with an mr of 20,621. the base composition of the pat gene is typical for streptomyces [70.1 mol% (g + c) in total and 93.5 mol% (g + c) in the third position]. translation of p ...	1988	3240868
vird proteins of agrobacterium tumefaciens are required for the formation of a covalent dna--protein complex at the 5' terminus of t-strand molecules.	the t-dna transfer process of agrobacterium tumefaciens is activated by the induction of the ti plasmid virulence (vir) loci by plant signal molecules such as acetosyringone. upon initiation of the t-dna transfer process, site-specific nicks occur at the 25-bp border sequences. this cleavage leads to the generation of a free, linear sst-dna molecule which is bound by sequence non-specific vire proteins. here we present evidence for the involvement of other acetosyringone-induced proteins in the ...	1988	3243272
binding-protein-dependent glucose transport by agrobacterium radiobacter grown in glucose-limited continuous culture.	agrobacterium radiobacter ncib 11883 was grown in glucose-limited continuous culture at low dilution rate. whole cells transported glucose using an energy-dependent mechanism which exhibited an accumulation ratio greater than 2000. three major periplasmic proteins were purified and their potential role as glucose-binding proteins (gbp) were investigated using equilibrium dialysis. two of these, gbp1 (mr 36,500) and gbp2 (mr 33,500), bound d-glucose with high affinity (kd 0.23 and 0.07 microm res ...	1988	3269386
the relationship between glucose transport and the production of succinoglucan exopolysaccharide by agrobacterium radiobacter.	agrobacterium radiobacter ncib 11883 was grown in ammonia-limited continuous culture at low dilution rate with glucose as the carbon source. under these conditions the organism produced an extracellular succinoglucan polysaccharide and transported glucose using the same periplasmic glucose-binding proteins (gbp1 and gbp2) as during glucose-limited growth. transition from glucose- to ammonia-limited growth was accompanied by a very rapid decrease in glucose uptake capacity, whereas the glucose-bi ...	1988	3269387
ornithine cyclodeaminase from ti plasmid c58: dna sequence, enzyme properties and regulation of activity by arginine.	nopaline, an abundant opine in plant cells transformed with nopaline-type ti plasmids, is catabolized in agrobacterium by three ti-plasmid-coded steps via arginine and ornithine to proline. the last enzyme, ornithine cyclodeaminase (ocd), converts ornithine directly into proline with release of ammonia. we describe the dna sequence of the ocd gene from ti plasmid c58, antiserum against an ocd fusion protein overexpressed in escherichia coli, induction and identification of the gene product in ag ...	1988	3281832
characterization of the virb operon from an agrobacterium tumefaciens ti plasmid.	the virulence genes of the agrobacterium tumefaciens ti plasmid are grouped into six transcription units and direct the transfer of t-dna into plant cells. we report here the nucleotide sequence of the largest vir operon, virb, from the ti plasmid ptia6nc. this operon contains 11 open reading frames, 7 of which show evidence of translational coupling. trpe::virb gene fusions were used to confirm the reading frames of genes virb2, 4, 5, 6, 7, 8, 10, and 11. in addition, the native gene products o ...	1988	3281947
[transfer of hybrid plasmids prp1.2::mini-mu into agrobacterium and rhizobium cells].	the study is devoted to determination of bacteriophage mu genome regions responsible for transfer limitation and instability of the plasmids in cells of strains of practically important microorganisms. with this aim in view, we determined the frequency of transfer into agrobacterium tumefaciens and rhizobium meliloti cells of plasmids with mini-mu phages carrying previously constructed deletions of various lengths. sharp decrease has been noted in the frequency of transfer into a. tumefaciens st ...	1988	3288538
minimal region necessary for autonomous replication of ptar.	the native 44-kilobase-pair plasmid ptar, discovered in a grapevine strain of agrobacterium tumefaciens, contains a single origin of dna replication confined to a 1.0-kilobase-pair region of the macromolecule. this region (ori) confers functions sufficient for replication in agrobacterium and rhizobium species but not in pseudomonas solanacearum, pseudomonas glumae, pseudomonas syringae pv. savastanoi, xanthomonas campestris pv. campestris, and escherichia coli. ori contains a repa gene that enc ...	1988	3290199
narrow- and broad-host-range symbiotic plasmids of rhizobium spp. strains that nodulate phaseolus vulgaris.	agrobacterium transconjugants containing symbiotic plasmids from different rhizobium spp. strains that nodulate phaseolus vulgaris were obtained. all transconjugants conserved the parental nodulation host range. symbiotic (sym) plasmids of rhizobium strains isolated originally from p. vulgaris nodules, which had a broad nodulation host range, and single-copy nitrogenase genes conferred a fix phenotype to the agrobacterium transconjugants. a fix phenotype was obtained with sym plasmids of strains ...	1988	16347637
host ranges of the incn group plasmid pcu1 and its minireplicon in gram-negative purple bacteria.	the bacterial host ranges of the conjugatively self-transmissible incn group plasmid pcu1 and its mobilizable miniderivative, pcu785, were examined. species of the gram-negative purple bacteria were chosen for this study. conjugative mobilization of pcu785 into a wide variety of bacteria was facilitated by the presence of orit of the broad-host-range plasmid rk2 in pcu785. although the host range of the incn tra system of pcu1 is broad, the host range of its replicon is limited. however, the pcu ...	1988	16347740
colonization of tomato plants by two agrocin-producing strains of agrobacterium tumefaciens.	for a bacterium to be a successful biocontrol agent against crown gall disease, it must produce an effective agrocin specific for agrobacterium tumefaciens and be able to colonize host plants efficiently. the colonization abilities of k84 and j73, successful and potential biocontrolling strains, respectively, were compared both in vivo and in vitro. both strains produced fibrils attaching them to tomato root surfaces and had similar colonization efficiencies up to 14 days after inoculation. howe ...	1988	16347802
transfer and expression of lithoautotrophy and denitrification in a host lacking these metabolic activities.	the conjugative 450-kilobase-pair megaplasmid phg1 from alcaligenes eutrophus h16 was transferred to the herbicide-degrading soil bacterium a. eutrophus jmp134. this transfer was achieved by means of rp4 mobilization and a tn5-mob insertion provided in trans on the megaplasmid replicon. although kanamycin-resistant transconjugants also occurred with other gram-negative species such as rhizobium, agrobacterium, and thiobacteria, a. eutrophus jmp134 was the only recipient which stably maintained t ...	1988	16347808
relocating a gene for herbicide tolerance: a chloroplast gene is converted into a nuclear gene.	the chloroplast gene psba codes for the photosynthetic quinone-binding membrane protein q(b), which is the target of the herbicide atrazine. this gene has been converted into a nuclear gene. the psba gene from an atrazine-resistant biotype of amaranthus hybridus has been modified by fusing its coding region to transcription-regulation and transit-peptide-encoding sequences of a bona fide nuclear gene. the constructs were introduced into the nuclear genome of tobacco by using the agrobacterium tu ...	1988	16593905
hairy roots are more sensitive to auxin than normal roots.	responses to auxin of lotus corniculatus root tips or protoplasts transformed by agrobacterium rhizogenes strains 15834 and 8196 were compared to those of their normal counterparts. three different types of experiments were performed, involving long-term, medium-term, or short-term responses to a synthetic auxin, 1-naphthaleneacetic acid. root tip elongation, proton excretion by root tips, and transmembrane electrical potential difference of root protoplasts were measured as a function of exogen ...	1988	16593928
factor inducing agrobacterium tumefaciens vir gene expression is present in monocotyledonous plants.	agrobacterium tumefaciens harboring the tumor-inducing ti plasmid incites crown gall tumor on dicotyledonous species. upon infection of these plants, ti plasmid dna sequence is stably transferred (t-dna) by unknown mechanisms to plant cells to be integrated into nuclear dna. the t-dna processing and transfer require the expression of vir (virulence) genes on the ti plasmid, which are known to be induced by certain phenolic compounds released from cells at the wounded inoculation site. the result ...	1988	16593930
isolation of genes involved in nodulation competitiveness from rhizobium leguminosarum bv. trifolii t24.	rhizobium leguminosarum bv. trifolii t24 produces a potent anti-rhizobial compound, trifolitoxin, and exclusively nodulates clover roots when in mixed inoculum with trifolitoxin-sensitive strains of r. leguminosarum bv. trifolii [schwinghamer, e. a. & belkengren r. p. (1968) arch. mikrobiol. 64, 130-145]. in the present study, the isolation of trifolitoxin production and resistance genes is described. a cosmid genomic library of t24 was prepared in plafr3. no trifolitoxin expression was observed ...	1988	16593933
an enhancer-like element present in the promoter of a t-dna gene from the ti plasmid of agrobacterium tumefaciens.	the promoter of the 780 gene of t-right [thomashow, m., nutter, r., montoya, a., gordon, m. & nester, e. (1980) cell 19, 729-739] from agrobacterium tumefaciens ti plasmid (pti15955) was shown to contain an upstream cis-acting element (activator) having enhancer-like properties. to characterize the properties of this promoter element, it was placed in both polarities, upstream and downstream of a delta-37 deletion mutant of the 780 gene. the delta-37 deletion contains the entire 780 gene with th ...	1988	16593943