| gene transfer in plants of brassica juncea using agrobacterium tumefaciens-mediated transformation. | an efficient system for gene transfer into plants of brassica juncea var. india mustard, mediated by agrobacterium tumefaciens. was developed through the manipulation of the culture medium and the use of the appropriate agrobacterium strain. high frequency shoot regeneration (90-100%) was obtained from hypocotyl explants grown on medium containing 0.9% agarose, 3.3 mg/l agno3 and 0.5-2 mg/l ba in combination with 0.01-0.05 mg/l 2,4-d or 0.1-1 mg/l naa. of all the agrobacterium strains tested, a. ... | 1991 | 24221663 |
| agrobacterium-mediated transformation and regeneration of kiwi fruit. | genetically transformed kiwi fruit (actinidia deliciosa) plants were obtained from hypocotyl and stem segments co-cultured with agrobacterium tumefaciens strain eha101 harboring a binary vector, plan411 or plan421, which contained the neomycin phosphotransferase ii (nptii) gene and the β-glucuronidase (gus) gene. after co-culturing with the a. tumefaciens, the hypocotyl or stem segments were cultured on a selection medium containing 25μg/ml kanamycin and 500μg/ml claforan. after one month in cul ... | 1991 | 24221658 |
| agrobacterium-mediated transformation of pepino and regeneration of transgenic plants. | regeneration of pepino (solanum muricatum ait.) shoots was achieved both by organogenesis and by embryogenesis. shoots derived via organogenesis were easily rooted and most regenerated plants appeared phenotypically normal. transgenic plants were obtained using the binary vector pkiwi110 in the avirulent agrobacterium tumefaciens strain lba4404. optimization of transformation protocols was rapidly achieved by monitoring early expression of the gus (β-d-glucuronidase) reporter gene carried on pki ... | 1991 | 24221548 |
| regeneration and agrobacterium-mediated transformation of chrysanthemum. | a method has been developed to regenerate shoots directly from leaf pieces of the autumn flowering chrysanthemum dendranthema indicum (l.) des moul (genotype korean). transgenic plants of this genotype were generated using transformation mediated by the disarmed strain of agrobacterium tumefaciens lba4404, containing either pkiwi110 or pga643. both pkiwi110 and pga643 contain the selectable marker gene neomycin phosphotransferase ii (nptii) and pkiwi110 also contains the reporter gene β-d-glucur ... | 1991 | 24221545 |
| effect of culture conditions on agrobacterium-mediated transformation in datura. | a two step selection procedure is described for high frequency transformation and regeneration of transgenic plants by coculture of leaf discs of datura innoxia with agrobacterium tumefaciens carrying binary vectors. leaf discs were cocultured with disarmed a. tumefaciens vectors pgs glucl, pgstrn943, pgv2260 and pbi121, and subcultured on regeneration media containing kanamycin. kanamycinresistant, putatively "transformed" callus and vegetative buds were isolated, and subcultured on media conta ... | 1991 | 24221401 |
| somatic hybridization between selected lycopersicon and solanum species. | mesophyll protoplasts of an interspecific lycopersicon esculentum mill, (tomato) x lycopersicon pennellii hybrid plant (ep) were fused with callus-derived protoplasts of solanum lycopersicoides dun. using a modified peg/dmso procedure. the ep plant was previously transformed by agrobacterium tumefaciens which carried the nptii and nopaline synthase genes. protoplasts were plated at 10(5)/ml in modified km medium and 16 days post-fusion 25 ug/ml kanamycin was added to the culture medium. during s ... | 1991 | 24221398 |
| agrobacterium-mediated transformation of solanum tuberosum l. cv. 'russet burbank'. | stem sections from shoot cultures maintained in vitro were used to produce transgenic plants of the potato, solanum tuberosum l. cv. 'russet burbank'. stem internode pieces inoculated with agrobacterium tumefaciens containing coat protein genes from potato virus x and potato virus y, produced shoots with a frequency of 60% in the absence of selection and 10% on medium containing 100 mg/l kanamycin monosulfate. regenerated shoots were assayed for kanamycin resistance by placing stem segments on c ... | 1991 | 24226160 |
| pemu: an improved promoter for gene expression in cereal cells. | a recombinant promoter, pemu, has been constructed to give a high level of gene expression in monocots. it is based on a truncated maize adh1 promoter, with multiple copies of the anaerobic responsive element from the maize adh1 gene and ocs-elements from the octopine synthase gene of agrobacterium tumefaciens. the pemu promoter was one of 12 different promoter constructs that were linked to the β-glucuronidase (gus) marker gene. promoter activity was measured 48 h after introduction of the cons ... | 1991 | 24221371 |
| a rapid and efficient regeneration system for pea (pisum sativum), suitable for transformation. | a method for plant regeneration via organogenesis in pea (pisum sativum) using nodal thin cell layer segments has been developed.from 10 to 12 days old sterile pea seedlings, nodal expiants were excised from which leaves and axillary buds were removed. shoot regeneration was consistently obtained from liquid cultures where the expiants were floated on the medium. shoots could be harvested after two weeks and thereafter up to ten weeks and no important effect of the cultivar (bodil, puget, rondo ... | 1991 | 24213691 |
| the effects of acetosyringone and ph on agrobacterium-mediated transformation vary according to plant species. | expiants of five plant species (allium cepa, antirrhinum majus, brassica campestris. glycine max, and nicotiana tabacum) were co-cultivated with three agrobacterium tumefaciens strains under different conditions to assess the effects of acetosyringone and medium ph on strain virulence. tumours were incited on all dicotyledonous species by strains n2/73 and a281. the presence of acetosyringone during co-cultivation generally enhanced the virulence of these strains, most markedly n2/73 on a. majus ... | 1991 | 24213690 |
| tissue-specific and stress-enhancing expression of the tr promoter for mannopine synthase in transgenic medicinal plants. | transgenic tobacco (nicotiana tabacum l.), licorice (glycyrrhiza uralensis fisher) and foxglove (digitalis purpurea l.) were obtained with binary vector systems based on a disarmed agrobacterium tumefaciens and on a virulent a. rhizogenes. the chimeric neomycin phosphotransferase ii (npt-ii) gene (kan) and the ß-glucuronidase (gus) gene (uida) were under the control of the tr1' and 2' promoters, respectively, on a binary vector, pgsgluc1. tissue-specific expression of the chimeric tr2' -uida gen ... | 1991 | 24193927 |
| insertional mutagenesis in arabidopsis thaliana: isolation of a t-dna-linked mutation that alters leaf morphology. | we investigated the potential of the agrobacterium tumefaciens t-dna as an insertional mutagen in arabidopsis thaliana. arabidopsis lines transformed with different t-dna vectors were generated using a leaf disc infection procedure adapted for efficient selection on either kanamycin or hygromycin medium. a standardized screening procedure was developed for the detection of recessive mutations in t2 populations of regenerated and/or transformed lines. recessive mutations originating from the tiss ... | 1991 | 24221214 |
| transformation of vicia narbonensis via agrobacterium-mediated gene transfer. | shoot tips and epicotyl-segments of vicia narbonensis were co-cultivated with agrobacterium tumefaciens strain c58c1 pgv 3850 hpt, carrying a plasmid coding for hygromycin-phosphotransferase. on callus-induction medium containing 60 mg/l hygromycin for selection, approximately 18% of the explants produced hygromycin-resistant callus. after transfer to regeneration-medium these calluses produced hygromycin-resistant and nopaline-positive somatic embryos which could be regenerated to plantlets. th ... | 1991 | 24220706 |
| optimizing the production of transformed pea (pisum sativum l.) callus using disarmed agrobacterium tumefaciens strains. | for optimization of the transformation procedure with pisum sativum l. stern explant callus was used to test the effect of disarmed agrobacterium tumefaciens strains, cocultivation procedures (preconditioning of explants; use of nicotiana tabacum l. nurse cultures), duration of cocultivation (2, 3 or 4 days), and agents for selection (kanamycin or hygromycin). the succinamopine strain eha101(pbi1042) produced the highest percentage of transformed calli (77%) when used in conjunction with tobacco ... | 1991 | 24213784 |
| 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 ... | 1990 | 24226938 |
| 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 ... | 1990 | 24226936 |
| 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 ... | 1990 | 24226826 |
| 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 ... | 1990 | 24226818 |
| 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 ... | 1990 | 24226815 |
| 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 ... | 1990 | 24226708 |
| 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 ... | 1990 | 24220903 |
| 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 ... | 1990 | 24220890 |
| 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 ... | 1990 | 24226603 |
| 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 ... | 1990 | 24226429 |
| 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 ... | 1990 | 24226372 |
| 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 ... | 1990 | 24226368 |
| 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 ... | 1990 | 24232928 |
| 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 ... | 1990 | 24226580 |
| 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. | 1990 | 24232780 |
| 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 ... | 1990 | 24232681 |
| agrobacterium mediated transfer of chlorsulfuron resistance to commercial flax cultivars. | agrobacterium tumefaciens carrying a disarmed ti-plasmid vector containing a chimeric npt-ll gene and a mutant acetolactate synthase gene (conferring resistance to the herbicide chlorsulfuron) from arabidopsis was used to transform flax (linum usitatissimum) hypocotyl tissue. transgenic regenerants were recovered from the inoculated tissue and were tested for expression of the foreign genes by leaf callus assays on kanamycin and on chlorsulfuron. transgenic plants were grown to maturity; selfed ... | 1989 | 24233525 |
| haploid transformation in brassica napus using an octopine-producing strain of agrobacterium tumefaciens. | microspore-derived embryos of brassica napus were transformed using the disarmed octopine-producing lba4404 strain of agrobacterium tumefaciens containing the binary vector pbin19. octopine-producing strains have previously been reported to be ineffective in transforming brassica. four actively growing yellow/ green sectors were selected from the embryos on 50 mg/l kanamycin and plants regenerated. analysis for npt-ii activity in these young plants initially indicated no expression of the bacter ... | 1989 | 24226014 |
| successful cocultivation of brassica napus microspores and proembryos with agrobacterium. | brassica napus microspores and microspore-derived proembryos were cocultivated with agrobacterium tumefaciens harbouring a binary vector. the vector contained selectable genes for kanamycin and hygromycin antibiotic resistance. microspores and proembryos survived the cocultivation procedure and subsequent antibiotic selection. thousands of plantlets can be regenerated from a single experiment. biochemical analysis indicated up to 7.3% of plants exhibited neomycin phosphotransferase ii enzyme act ... | 1989 | 24233359 |
| agrobacterium tumefaciens and interkingdom genetic exchange. | | 1989 | 25945402 |
| incorporation of hygromycin resistance in brassica nigra and its transfer to b. napus through asymmetric protoplast fusion. | with the idea to develop a selection system for asymmetric somatic hybrids between oilseed rape (brassica napus) and black mustard (b. nigra), the marker gene hygromycin resistance was introduced in this last species by protoplast transformation with the disarmed agrobacterium tumefaciens strain c58 pgv 3850 hpt. the b. nigra lines used for transformation had been previously selected for resistance to two important rape pathogens (phoma lingam, plasmodiophora brassicae). asymmetric somatic hybri ... | 1989 | 24227144 |
| heavy metal tolerant transgenic brassica napus l. and nicotiana tabacum l. plants. | a chimeric gene containing a cloned human metallothionein-ii (mt-ii) processed gene was introduced into brassica napus and nicotiana tabacum cells on a disarmed ti-plasmid of agrobacterium tumefaciens. transformants expressed mt protein as a mendelian trait and in a constitutive manner. seeds from self-fertilized transgenic plants were germinated on media containing toxic levels of cadmium and scored for tolerance/ susceptibility to this heavy metal. the growth of root and shoot of transformed s ... | 1989 | 24227139 |
| thiophene accumulation in relation to morphology in roots of tagetes patula : effects of auxin and transformation by agrobacterium. | roots of marigold (tagetes patula l.) accumulate thiophenes, heterocyclic sulfurous compounds with strong biocidal activity. in detached roots cultured in vitro, the thiophene content was 5 μmol·(g fresh weight)(-1) which is 25-times higher than in roots attached to the plant. in roots derived from tissues transformed by agrobacterium tumefaciens and a. rhizogenes, the morphology and thiophene content varied with the bacterial strain used. transformation stimulated the elongation of the root tip ... | 1989 | 24201420 |
| virulence of agrobacterium tumefaciens strains with brassica napus and brassica juncea. | brassica napus and brassica juncea were infected with a number of agrobacterium tumefaciens strains. tumourigenesis was very rapid and extremely efficient on b. juncea with all but one of the strains. tumourigenesis on b. napus varied widely. it was very efficient with the nopaline strains, was reduced with the succinamopine strain a281 and was very weak with the octopine strains. the latter observation was confirmed with six different b. napus rapeseed cultivars. the selectivity was due to diff ... | 1989 | 24233232 |
| specificity of strain and genotype in the susceptibility of pea to agrobacterium tumefaciens. | to determine the best combination for potential use in transformation of pisum sativum l., 13 genotypes were inoculated with wild-type agrobacterium tumefaciens strains a281, c58 and ach5. a281 appeared to be the most virulent strain, as determined by size and number of tumours, followed by c58 and ach5. genotypes differed considerably in their response to inoculation and genotype x strain interaction was evident. genotypes also responded differently to in vivo or in vitro inoculation. axenic ca ... | 1989 | 24233224 |
| transformation of homozygous diploid potato with an agrobacterium tumefaciens binary vector system by adventitious shoot regeneration on leaf and stem segments. | transformed potato (solanum tuberosum) plants were obtained from homozygous diploid potato by using a transformation procedure in combination with an adventitious shoot regeneration method. leaf and stem explants were inoculated with an agrobacterium tumefaciens strain which contained a binary vector (pvu 1011) carrying the neomycin phosphotransferase gene. shoot regeneration most effectively on stem explants, occurred within six weeks directly from the explants without introducing a callus phas ... | 1989 | 24272868 |
| isolation and functional analysis of a set of auxin genes with low root-inducing activity from an agrobacterium tumefaciens biotype iii strain. | a new type of root-inducing iaa gene set was cloned from the ti plasmid of the biotype iii agrobacterium tumefaciens strain tm-4. these iaa genes are characterized by a very low dna homology with the well-characterized iaa gene set, iaam and iaah, of the "common dna" region of the biotype i strain ach5 and by a low root-inducing activity.the biological activities of both iaa gene sets were compared by transferring each into a disarmed ti vector and by testing the resulting strains on nicotiana r ... | 1989 | 24272862 |
| genetic transformation of apple (malus pumila mill.) using a disarmed ti-binary vector. | the disamed ti-binary vector pbin 6 in agrobacterium tumefaciens has been used in leaf disc transfomations to produce transgenic apple (malus pumila mill.) plants with a nomal phenotype except for a somewhat reduced capacity to root. the presence of the genes for nopaline synthase and neomycin phosphotrans ferase (conferring kanamycin resistance), inserted into the host genome by the vector, was confirmed by southern blot analysis, the detection of nopaline synthase activity and rooting in the p ... | 1989 | 24240455 |
| biotransformation of nicotine alkaloids by tobacco shooty teratomas induced by a ti plasmid mutant. | tobacco shooty or rooty teratomas and hairy roots were induced by agrobacterium tumefaciens (pgv 3845), a. tumefaciens (pgv 3304) and a. rhizogenes (pri 8196), respectively. the tobacco alkaloids, nicotine, nornicotine and anatabine, were produced in hairy roots and in rooty teratomas but not in shooty teratomas. however, the shooty teratomas have the ability to accumulate the alkaloids and to biotransform nicotine to nornicotine. these were established by co-culture experiments incubating hairy ... | 1989 | 24240441 |
| analysis of a chimeric class-i patatin-gus gene in transgenic potato plants: high-level expression in tubers and sucrose-inducible expression in cultured leaf and stem explants. | patatin is a family of lipid acyl hydrolases that accounts for 30 to 40% of the total soluble protein in potato (solanum tuberosum l.) tubers. to examine the regulation of the patatin genes, we constructed a chimeric gene containing 2.5 kb of 5' flanking sequence from the class i patatin genomic clone ps20 transcriptionally fused to β-glucuronidase (gus) and introduced it into potato plants using an agrobacterium tumefaciens tiplasmid vector. while the chimeric gene was expressed at high levels ... | 1989 | 24272716 |
| sites of synthesis, translocation and accumulation of pyrrolizidine alkaloid n-oxides in senecio vulgaris l. | (14)c-labelled alkaloid precursors (arginine, putrescine, spermidine) fed to senecio vulgaris plants via the root system were rapidly taken up and efficiently incorporated into the pyrrolizidine alkaloid senecionine n-oxide (sen-nox) with total incorporations of 3-6%. considerable amounts of labelled sen-nox were translocated into the shoot and were directed mainly into the inflorescences, the major sites of pyrrolizidine-alkaloid accumulation. detached shoots of s. vulgaris were unable to synth ... | 1989 | 24212277 |
| high efficiency agrobacterium tumefaciens-mediated transformation of arabidopsis thaliana leaf and cotyledon explants. | a highly efficient and fast agrobacterium-mediated leaf disc transformation system for the arabidopsis thaliana l. genotype c24 was developed. this protocol is also amenable to other ecotypes - as could be shown for landsberg erecta and wassllewskija. besides the hygromycin selection also the g418 and kanamycin selection were established. furthermore the described procedure is appliable not only to leaf explants but also to expanded cotyledons which proved to be an excellent alternative as expla ... | 1988 | 24240423 |
| parameters affecting the frequency of kanamycin resistant alfalfa obtained by agrobacterium tumefaciens mediated transformation. | kanamycin resistant plants of medicago varia a2 were obtained by an optimized procedure for high frequency transformation using agrobacterium tumefaciens infection of leaf and petiole tissue. parameters which affected the frequency were explant type, the agrobacterium strain used and the time allowed for cocultivation. under optimum conditions, i.e., using the agrobacterium strain a281 and a 4 day cocultivation period, the frequency of transformed leaflets obtained was greater than 70%. | 1988 | 24240404 |
| transformation and regeneration of brassica oleracea mediated by an oncogenic agrobacterium tumefaciens. | a chimaeric neomycin phosphotransferase ii (npt ii) gene was introduced in brassica oleracea using an oncogenic strain of agrobacterium tumefaciens harbouring ti plasmid which contains nos/nptii in its t-dna. the transformation of b. oleracea with the oncogenic ti plasmid, resulted in regeneration of shoots and roots without any exogenous requirement of phytohormones. the presence of npt ii gene was determined by hybridization of tn5 encoded npt ii gene with dna of kanamycin resistant regenerate ... | 1988 | 24240402 |
| the agrobacterium tumefaciens t-dna gene 6(b) is an onc gene. | in this article it is shown that the t-dna of agrobacterium tumefaciens contains besides the well-known cyt and aux genes another gene with an oncogenic effect in plants. the gene in question is called 6(b) and causes the formation of small tumors in plant species such as nicotiana glauca and kalanchoe tubiflora. | 1988 | 24272629 |
| function of heterologous and pseudo border repeats in t region transfer via the octopine virulence system of agrobacterium tumefaciens. | the successful transfer of the ti plasmid t region to the plant cell is mediated by its 24 bp border repeats. processing of the t-region prior to transfer to the plant cell is started at the right border repeat and is stimulated by a transfer enhancer sequence called "overdrive". left and right border repeats differ somewhat in nucleotide sequence; moreover, the repeats of different ti and ri plasmids are slightly different. our data indicate that these differences do not have a significant infl ... | 1988 | 24272627 |
| a modified storage protein is synthesized, processed, and degraded in the seeds of transgenic plants. | in vitro mutagenesis was used to supplement the sulfur amino acid codon content of a gene encoding β-phaseolin, a phaseolus vulgaris storage protein. the number of methionine codons in the phaseolin gene was increased from three to nine by insertion of a 45 base pair (bp) synthetic duplex. either modified or normal phaseolin genes were integrated into the genome of tobacco plants through agrobacterium tumefaciens-mediated transformation. although similar levels of phaseolin rna are detected in s ... | 1988 | 24272623 |
| genotype-independent leaf disc transformation of potato (solanum tuberosum) using agrobacterium tumefaciens. | leaves of the in vitro grown potato cultivars 'bintje', 'berolina', 'desiree', and 'russet burbank' were wounded and co-cultivated with agrobacterium strains having chimeric bar and nptii genes on a disarmed t-dna. each leaf from these cultivars formed numerous calli on kanamycin-containing medium, and almost all calli regenerated shoots. for 'russet burbank', it was necessary to include agno3 in the medium to obtain efficient shoot regeneration. the transformed plants have one to a few copies o ... | 1988 | 24232356 |
| mass-spectrometric quantitation of cytokinins in tobacco crown-gall tumours induced by mutated octopine ti plasmids of agrobacterium tumefaciens. | the levels of the major cytokinins, zeatin, zeatin riboside, zeatin riboside-5'-monophosphate and zeatin-7-glucoside were measured in tobacco (nicotiana tabacum l.) crown-gall tissues carrying insertion and deletion mutations in the t-dna. measurements were made by combined gas chromatography-mass spectrometry using selected ion monitoring with (15)n- and (2)h-labelled internal standards. the results demonstrate that, relative to wild-type tumour tissue, cytokinin levels are considerably elevate ... | 1988 | 24220777 |
| variability in tissue cultures of choisya ternata. iii comparing alkaloid production in cell lines obtained by various strategies. | callus cultures of choisya ternata have been prepared by different strategies: aggregate clones, subclones and protoclones obtained from well-established strains; protoclones obtained from mesophyll tissue; cultures transformed by agrobacterium tumefaciens. all of them show high variability in their dihydrofuroquinoline alkaloid production. as compared to the alkaloid content of the whole plant, one alkaloid (platydesminium) could be obtained in higher amounts in some lines, but it was impossibl ... | 1988 | 24240269 |
| the sequence of a pea vicilin gene and its expression in transgenic tobacco plants. | a 5.5 kb eco ri fragment containing a vicilin gene was selected from a pisum sativum genomic library, and the protein-coding region and adjacent 5' and 3' regions were sequenced. a dna construction comprising this 5.5 kb fragment together with a gene for neomycin phosphotransferase ii was stably introduced into tobacco using an agrobacterium tumefaciens binary vector, and the fidelity of expression of the pea vicilin gene in its new host was studied. the seeds of eight transgenic tobacco plants ... | 1988 | 24272502 |
| changes in the tissue-specific prevalence of translatable mrnas in transgenic tobacco shoots containing the t-dna cytokinin gene. | two-dimensional gel electrophoresis of in vitro translation products was used to examine differences between the steady state rna populations of an untransformed tobacco plant line and a non-rooting tobacco shoot line transformed with a t l -dna segment from agrobacterium tumefaciens carrying the cytokinin gene (t-cyt). the analysis comprised about 240 translation products representing the more abundant mrnas. approximately 8% of the translation products were found to have significantly differen ... | 1988 | 24272496 |
| the 5' flanking region of a barley b hordein gene controls tissue and developmental specific cat expression in tobacco plants. | the 549 base pairs of the 5' flanking region of a barley seed storage protein (b1 hordein) gene were linked to the reporter gene encoding chloramphenicol acetyl transferase (cat). the chimaeric gene was transferred into tobacco plants using agrobacterium tumefaciens. cat enzyme activity was detected in the seeds, but not in the leaves, of the transgenic plants. furthermore, enzyme activity was found only in the endosperm, and only from fifteen days after pollination. in contrast, the constitutiv ... | 1988 | 24277567 |
| right-border sequences enable the left border of an agrobacterium tumefaciens nopaline ti-plasmid to produce single-stranded dna. | the t-region of nopaline-type ti-plasmids (the portion of the plasmid that is transferred to plant cells) of agrobacterium tumefaciens is delimited by 23-25 bp direct repeats. they are nicked by the products of the vird locus and the presence of these nicked sites is correlated with the synthesis of single-stranded t-region copies. despite previous indications to the contrary, we show that the ptit37 t-region left border is capable of producing single-stranded dna with high efficiency and that i ... | 1988 | 24272395 |
| transformed callus does not necessarily regenerate transformed shoots. | agrobacterium tumefaciens carrying a disarmed ti plasmid vector was used for the transformation of flax tissue. transformed callus was obtained from inoculated hypocotyl segments and healthy green shoots were regenerated from this callus. nopaline assays on shoot tissue were positive for nopaline content if carried out soon after removal of the shoot from the callus but negative if carried out 2-3 weeks after removal. all of these shoots gave rise to kanaymcin sensitive progeny and were most lik ... | 1988 | 24241768 |
| glyphosate tolerant flax plants from agrobacterium mediated gene transfer. | agrobacterium tumefaciens carrying a disarmed ti-plasmid vector containing a chimeric npt-ii gene and a glyphosate resistance plant-derived 5-enolpyruvylshikimate-3-phosphate synthase gene was used to transform flax hypocotyl tissues. transformed shoots could be regenerated from the inoculated tissue and were proven to be transgenic by the combination of leaf callus assays, nopaline assays and progeny tests. co-segregation was observed in the progeny for kanamycin and glyphosate resistance. | 1988 | 24241767 |
| genetic transformation of 9 in vitro clones of alnus and betula by agrobacterium tumefaciens. | crown gall tumorigenesis, integration and expression of t-dna encoded genes from agrobacterium tumefaciens were investigated in 9 clones of alnus glutinosa, a. incana and betula papyrifera. tumor formation on in vitro shoots was frequent in all clones with strain ach5 and present in 8 clones with strain c58. tumors excised from shoots were selected for autotrophic growth in vitro and axenic cultures were established. octopine or nopaline, respective of the strain type used for inoculation, was d ... | 1988 | 24241754 |
| tissue-specific expression of a pea legumin gene in seeds of nicotiana plumbaginifolia. | a 3.4-kilobase genomic dna fragment from pisum sativum l. containing the lega gene, which encodes a major legumin storage protein, was transferred to nicotiana plumbaginifolia using an agrobacterium tumefaciens strain containing the bin 19 binary vector system. northern hybridisation analysis of lega-transformed plants demonstrated that legumin-specific rna was present in developing seeds but not in developing leaves. legumin protein was immunologically detected in the mature seeds of lega-trans ... | 1988 | 24277514 |
| expression and inheritance of kanamycin resistance in a large number of transgenic petunias generated by agrobacterium-mediated transformation. | one hundred and four kanamycin-resistant petunia "mitchell" plants were regenerated from leaf discs cocultivated with agrobacterium tumefaciens strain lba4404 containing a binary vector pcgn200. selection for kanamycin resistance was applied during plant regeneration at the initiation of both shoots and roots. the regenerated plants were analysed for expression and inheritance of their kanamycin resistance phenotype. approximately half of the plants showed normal mendelian inheritance for one or ... | 1988 | 24272348 |
| molecular characterization of the virulence gene vira of the agrobacterium tumefaciens octopine ti plasmid. | the virulence loci play an essential role in tumor formation by agrobacterium tumefaciens. induction of vir gene expression by plant signal molecules is solely dependent on the virulence loci vira and virg. this study focused on the vira locus of the octopine type ti plasmid pti15955. the nucleic acid sequence of a 5.7-kilobase fragment encompassing vira was determined. genetic analysis of this region revealed that vira contains one open reading frame coding for a protein of 91 639 daltons. immu ... | 1988 | 24272265 |
| differential expression of conglycinin α' and β subunit genes in transgenic plants. | β-conglycinin or 7s protein, one of the two major storage proteins of soybean (glycine max), is comprised of three subunits, α', α and β. genomic clones encoding the α' and β subunit genes were ligated together in intermediate plasmids, either in direct orientation (← ←) or in divergent orientation (← →). in the latter instance the transcriptional promoters of the two genes were approximately 2.0 kb apart. the dnas were introduced into leaf disks of petunia hybrida on a disarmed ti plasmid in ag ... | 1988 | 24272254 |
| celery transformation by agrobacterium tumefaciens: cytological and genetic analysis of transgenic plants. | transgenic celery plants were obtained following co-cultivation of petiole explants with agrobacterlum tumefaciens containing pmon200, a cointegrate vector carrying genes for kanamycin resistance and nopaline synthase. transformants were selected by ability of callus to grow in the presence of 50mg/l kanamycin. transformation was confirmed either by the presence of nopaline or by southern blots. cytological analysis of 14 transformed plants revealed chromosomal aberrations, both in structure and ... | 1988 | 24241542 |
| detection of a non-structural protein of m r 11 000 encoded by the virion dna of maize streak virus. | a polypeptide of approximately 11 000 daltons (11 kda protein) encoded by an open reading frame (10.9 orf) from the virion sense of maize streak virus (msv) dna has been detected among the products of in vitro translation reactions programmed with rna from infected maize plants and also in total protein extracts from infected leaves. the 11 kda protein has not been detected in virions and is therefore proposed to have a nonstructural role.viral dna with an additional in-frame translation stop co ... | 1988 | 24272158 |
| agroinfection and nucleotide sequence of cloned wheat dwarf virus dna. | cloned dna of the geminivirus wheat dwarf virus (wdv) was successfully used to infect seedling wheat plants. the clone was derived from circular double-stranded viral dna isolated from naturally infected tissue. the initiation of infection was mediated by agrobacterium tumefaciens using cloned dimeric wdv genomes in a binary agrobacterium vector. the wdv dna which comprised the infectious clone was sequenced and is compared with the published sequence of a swedish isolate of the same virus. the ... | 1988 | 24272156 |
| introduction of foreign genes into potato cultivars bintje and désirée using an agrobacterium tumefaciens binary vector. | tuber discs of solanum tuberosum cv bintje and désirée were cocultivated with an agrobacterium tumefaciens binary vector, carrying both the neomycine phosphotransferase and the e. coli β-glucuronidase gene fused to resp. the nopaline synthase and cauliflower mosaic virus 35s promotor.inoculated tuber discs produce transgenic shoots in selective media containing kanamycin. the transgenic plants are phenotypically normal and contain the euploid number of chromosomes. both the neomycin phosphotrans ... | 1988 | 24241414 |
| a rapid transformation method for solanum tuberosum using binary agrobacterium tumefaciens vectors. | a tuber disc transformation and regeneration system was devised for potato (solanum tuberosum). tuber discs were found to be the most morphogenetic organ on a medium previously optimised for tomato regeneration. shoot regeneration from tuber discs was rapid and transformed as shown by nopaline assays and southern blot analysis. the ease and speed of the tuber disc method will allow for the increased use of this commercially important plant in transformation studies. | 1988 | 24241405 |
| transformation of lettuce (lactuca sativa) mediated by agrobacterium tumefaciens. | lactuca sativa can be routinely transformed using ti plasmids of agrobacterium tumefaciens containing a chimeric kanamycin resistance gene (nos.nptii.nos). critical experimental variables were plant genotype, bacterial concentration, presence of a nurse culture and timing of transfers between tissue culture media. transformation was confirmed by the ability to callus and root in the presence of kanamycin, nopaline production, and by hybridization in southern blots. transformation has been achiev ... | 1987 | 24248927 |
| the pseudomonas savastanoi tryptophan-2-mono-oxygenase is biologically active in nicotiana tabacum. | it has been proposed that the "eukaryotic" t-dna-encoded indole-3-acetic acid (iaa) biosynthesis genes of agrobacterium tumefaciens and their prokaryotic counterpart in pseudomonas savastanoi originated from common ancestor genes. this paper provides additional evidence for the functional similarity between the gene products. we have demonstrated that a chimeric gene consisting of the coding sequence of the p. savastanoi tryptophan-2-mono-oxygenase (iaam gene) and a plant promoter encodes an act ... | 1987 | 24226077 |
| auxin-induced rapid changes in translatable mrnas in tobacco cell suspension. | when 2,4-dichlorophenoxyacetic acid (2,4-d)-dependent tobacco cell suspensions, one normal and one transformed by agrobacterium tumefaciens, were subcultured on hormone-lacking medium the stationary phase of the cell cycle was reached earlier than on medium containing 2,4-d. addition of the auxin 2,4-d could restore cell division activity within 10-12 h for the most rapidly reacting cell line. the cell-division response was characterized as being auxin-specific and optimal with 2,4-d at 2.2 10(- ... | 1987 | 24226071 |
| molecular characterization of the virulence gene vira of the agrobacterium tumefaciens octopine ti plasmid. | the virulence loci play an essential role in tumor formation by agrobacterium tumefaciens. induction of vir gene expression by plant signal molecules is solely dependent on the virulence loci vira and virg. this study focused on the vira locus of the octopine type ti plasmid pti15955. the nucleic acid sequence of a 5.7-kilobase fragment encompassing vira was determined. genetic analysis of this region revealed that vira contains one open reading frame coding for a protein of 91 639 daltons. immu ... | 1987 | 24277199 |
| genetic transformation of flax (linum usitatissimum) by agrobacterium tumefaciens: regeneration of transformed shoots via a callus phase. | genetic transformation of flax (linum usitatissimum) has been achieved using an a. tumefaciens strain carrying a non-oncogenic ti plasmid-derived vector containing a chimaeric npt-ii gene and a wild type nopaline synthase gene. fertile, transformed shoots were most easily obtained from km(r) callus developing on hypocotyl sections. the totipotency of the km(r) callus was dependent upon its origin. t-dna was visualised by southern blotting in all km(r) tissues. efficient expression of nopaline sy ... | 1987 | 24248856 |
| transformation of brassica napus with agrobacterium tumefaciens based vectors. | a reproducible system to produce transgenic brassica napus plants has been developed using stem segments. stem segments from 6-7 week old plants were inoculated with an agrobacterium tumefaciens strain containing a disarmed tumor-inducing plasmid ptit37-se carrying a chimeric bacterial gene encoding kanamycin resistance (pmon200). stem explants were cocultured for 2 days before transfer to kanamycin selection medium. shoots regenerated directly from the explant in 3-6 weeks and were excised, dip ... | 1987 | 24248835 |
| genetic transformation in two potato cultivars with t-dna from disarmed agrobacterium. | derivatives of potato (solanum tuberosum cv.'s 'maris bard' and 'desiree') transformed with disarmed t-dna from genetically engineered agrobacterium tumefaciens strains were isolated. the transformed plants were recovered from shoot-forming tumours induced by infection of wounds with mixedcultures of shoot-inducing a. tumefaciens strains t37 and either agrobacterium strain lba1834(pral1834), (hille et al. 1983) or lba4404(pbin6; pral4404), (bevan 1984). two small-scale feasibility experiments ga ... | 1987 | 24241200 |
| initiation of auxin autonomy in nicotiana glutinosa cells by the cytokinin-biosynthesis gene from agrobacterium tumefaciens. | agrobacteria carrying mutations at the auxin-biosynthesizing loci (iaah and iaam of the ti plasmid) induce shoot-forming tumors on many plant species. in some cases, e.g. nicotiana glutinosa l., tumors induced by such mutant strains exhibit an unorganized and fully autonomous phenotype. these characteristics are stable in culture at both the tissue and cellular level. we demonstrate that the cytokinin-biosynthesis gene (ipt) of the ti plasmid is responsble for the induction of both auxin and cyt ... | 1987 | 24225718 |
| acetosyringone promotes high efficiency transformation of arabidopsis thaliana explants by agrobacterium tumefaciens. | high frequency transformation of arabidopsis thaliana leaf explants has been obtained using a disarmed ti plasmid containing the coding region of a neomycin phosphotransferase gene (npt ii) as a selectable marker. the rate of transformation ranged from 55 to 63 percent when acetosyringone (as), a natural wound response molecule, was added to an agrobacterium tumefaciens culture prior to incubation with leaf segments. without acetosyringone, the transformation rate was approximately 2 to 3 percen ... | 1987 | 24301191 |
| expression of a soybean β-conclycinin gene under the control of the cauliflower mosaic virus 35s and 19s promoters in transformed petunia tissues. | a gene encoding the α'-subunit of β-conglycinin was ligated to the 19s and 35s promoters of cauliflower mosaic virus and introduced into petunia plants on a disarmed ti-plasmid using agrobacterium tumefaciens. transformed cells were regenerated into whole plants and ummunoreactive polypeptides and hybridizable, polyadenylated mrna were detected in transformed tissues. expression from the 35s promoter was 10 to 50 times greater than expression from the 19s promoter. the level of immunodetectable ... | 1987 | 24277084 |
| correlation between binding of agrobacterium tumefaciens by root cap cells and susceptibility of plants to crown gall. | we compared the binding of agrobacterium tumefaciens by freshly isolated root cap cells with susceptibility of plants to crown gall tumorigenesis. a high binding reaction was strongly correlated with susceptibility to tumorigenesis in a survey of the binding of strain b6 to cells from 48 species in 17 families. in reciprocal experiments with nine virulent a. tumefaciens strains, tumors developed in plant-bacteria combinations that gave a high binding response in the root cap cell assay. binding ... | 1987 | 24248761 |
| endogenous indoles and the biosynthesis and metabolism of indole-3-acetic acid in cultures of rhizobium phaseoli. | gas chromatography-mass spectrometric analyses of purified extracts from cultures of rhizobium phaseoli wild-type strain 8002, grown in a non-tryptophan-supplemented liquid medium, demonstrated the presence of indole-3-acetic acid (iaa), indole-3-ethanol (iet), indole-3-aldehyde and indole-3-methanol (im). in metabolism studies with (3)h-, (14)c- and (2)h-labelled substrates the bacterium was shown to convert tryptophan to iet, iaa and im; iet to iaa and im; and iaa to im. indole-3-acetamide (ia ... | 1987 | 24227443 |
| structure, organization and expression of transferred dna in nicotiana plumbaginifolia crown-gall tissues. | data are provided which show that transferred dna (t-dna) present in nicotiana plumbaginifolia crown-gall lines in most cases was scrambled and not intact. both wild-type, and 'rooter'- and 'shooter'-type mutants of octopine-type agrobacterium tumefaciens were used to infect n. plumbaginifolia plantlets, cultured in vitro. resulting tumors were excised from the plantlets and cultured for more than three years. during subculturing the tumor lines were scored for the following phenotypic traits: p ... | 1987 | 24227439 |
| transformation of stylosanthes spp. using agrobacterium tumefaciens. | tumours were incited on leaf sections of stylosanthes humilis, s. hamata, s. guianensis and s. scalra following infection by agrobacterium tumefaciens. the suitability of 2 binary vectors (pga472, bin6) for gene transfer in s. humilis was tested and kanamycin-resistant tumour tissue was obtained from infected leaf pieces. the presence and expression of the neomycin phosphotransferase (npt ii) gene in the plant cells was demonstrated by hybridization of the coding region of the npt ii gene of the ... | 1987 | 24248653 |
| callus induction from protoplasts of v. unguiculata, v. sublobata and v. mungo. | protoplasts were isolated from hypocotyl of v. mungo (l.) hepper or hypocotyl-derived callus of v. sublobata (phaseolus sublobata roxb.) and v. unguiculata (l.) walp (syn. v. sinensis (l.) saviex hassk) using an enzyme solution comprising cellulase 2.5%, macerozyme, hemicellulase and driselase each at a 0.5% level in 0.5 m sorbitol. isolated protoplasts were cultured in murashige and skoog's (1962) basal liquid medium supplemented with ba, naa, 2,4-d (1 mg/l each) and sucrose (14%). after four w ... | 1987 | 24241464 |
| transformation of cotton (gossypium hirsutum l.) by agrobacterium tumefaciens and regeneration of transgenic plants. | cotton (gossypium hirsutum l.) cotyledon tissues have been efficiently transformed and plants have been regenerated. cotyledon pieces from 12-day-old aseptically germinated seedlings were inoculated with agrobacterium tumefaciens strains containing avirulent ti (tumor-inducing) plasmids with a chimeric gene encoding kanamycin resistance. after three days cocultivation, the cotyledon pieces were placed on a callus initiation medium containing kanamycin for selection. high frequencies of transform ... | 1987 | 24277496 |
| transformation of soybean protoplasts from permanent suspension cultures by cocultivation with cells of agrobacterium tumefaciens. | cell wall regenerating protoplasts from soybean cells kept in suspension culture were cocultivated with bacteria which were derived from the nopaline strain c58 of agrobacterium tumefaciens. when the bacteria carried an oncogenic ti-plasmid, about 5% of the surviving protoplasts were able to form calli on hormone-free agar in contrast to controls, where bacteria without ti-plasmid were applied, and where no calli were formed. after isolation of dna from hormone-independently growing cells furthe ... | 1987 | 24276903 |
| chromosomal nodulation genes: sym-plasmid containing agrobacterium strains need chromosomal virulence genes (chva and chvb) for nodulation. | the chromosomal genes chva and chvb of agrobacterium tumefaciens, which mediate attachment to plant cells, were found to be essential not only for tumour induction but also for the formation of root nodules on plants. | 1987 | 24302529 |
| functional analysis of the agrobacterium tumefaciens octopine ti-plasmid left and right t-region border fragments. | border fragments of the octopine ti-plasmid were tested for their ability to restore tumorigenicity of an avirulent mutant carrying a deleted right border. it was found that neither introduction of left border fragments nor that of small right border fragments at the position of the deletion resulted in a complete restoration of oncogenicity. however, insertion of a larger right border fragment in the deletion mutant gave fully oncogenic strains. in the latter case sequences to the right side of ... | 1987 | 24302528 |
| t-dna rearrangements due to tissue culture: somaclonal variation in crown gall tissues. | after three years of apparent stability in tissue culture, the single cell derived shooty crown gall line snt1.013 produced a revertant shoot which had switched from non-rooting (rod(+)) and octopine synthesizing (ocs(+)) to rod(-) ocs(-), indicating that in this revertant tl-dna genes 4 (causing the rod(+) trait) and gene 3 (causing the ocs(+) trait) had been inactivated. southern blots revealed that the inactivation of these t-dna genes was the result of a considerable rearrangement of dna seq ... | 1987 | 24276797 |
| neoplastic progression in crown gall in tobacco without elevated auxin levels. | we have isolated two stable variants from a crown-gall teratoma tissue of tobacco (nicotiana tabacum l.) transformed by agrobacterium tumefaciens strain a66, a mutant of the virulent a6 strain containing an insertion sequence in the tumor-inducing (ti) plasmid at the locus coding for auxin biosynthesis. normally tobacco cells transformed by strain a66 spontaneously form shoots in culture and will not grow on hormone-free medium unless shoots develop. the variant tissue lines, isolated from the t ... | 1986 | 24232660 |
| potato spindle tuber viroid infections mediated by the ti plasmid of agrobacterium tumefaciens. | full length copies of potato spindle tuber viroid (pstv) were introduced into plant cells using an agrobacterium tumefaciens vector. crown galls containing the pstv dna were induced on tomato plants, and the plants analysed for systemic replication of the viroid. two separately derived multimeric pstv insertions in the t-dna were infectious on every plant inoculated. however, monomeric pstv gave rise to significant levels of infection only when an adjacent plant promoter could direct transcripti ... | 1986 | 24307321 |
| changes in translatable poly(a) rna from differentiated potato tissues transformed with shoot-inducing ti tl-dna of agrobacterium tumefaciens. | two dimensional gel electrophoresis was used to examine differences in steady state total poly(a) rna from untransformed potato (solanum tuberosum cv. maris bard) and potato transformed with shoot-inducing tl-dna from a. tumefaciens. rna was compared from phenotypically very distinct in vitro cultured shoots, more similar grafted plants and tubers. in each case between 200-400 translation products were identified representing the more abundant poly(a) mrna's. in general, poly(a) rna from the tra ... | 1986 | 24307320 |
| isozyme gene expression in potato tumors incited by agrobacterium. | two plant tumors (crown galls and hairy roots) were experimentally provoked on potato cv. 'désirée' by oncogenic strains of agrobacterium tumefaciens and a. rhizogenes. a marked shift in the expression of some organ-specific genes occurred in crown galls derived from the central zone of tubers: two novel isozyme genes (est-b and pox-e) were expressed, two others (est-c and pox-f) were suppressed and the remaining ones were maintained in the original state. when the starting tissue was the stem s ... | 1986 | 24247945 |
| site-specific mutagenesis of potato spindle tuber viroid cdna: : alterations within premelting region 2 that abolish infectivity. | the infectivity of cloned viroid cdnas permits investigation of structure/function relationships in these unusual pathogenic rnas by systematic site-specific mutagenesis of the cdnas and subsequent bioassay. we have used three different strategies to create nucleotide substitutions within premelting region 2, a region of potato spindle tuber viroid (pstv) believed to be important in viroid replication: sodium bisulfitecatalyzed deamination of deoxycytosine residues, oligonucleotide-directed muta ... | 1986 | 24307277 |
| conservation of is66 homologue of octopine ti plasmid dna in rhizobium fredii plasmid dna. | dna sequences homologous to the t-dna region of the octopine ti plasmid from agrobacterium tumefaciens are found in various fast-growing rhizobium fredii strains. the largest fragment (bamhi fragment 2) at the right-boundary region of the 'core' t-dna hybridizes to more than one plasmid present in r. fredii. however, one smaller fragment (ecori fragment 19a) adjacent to the 'core' t-dna shows homology only with the plasmid carrying the symbiotic nitrogen-fixation genes (psym). hybridization data ... | 1986 | 24302303 |
| bleomycin resistance: a new dominant selectable marker for plant cell transformation. | plant cells are sensitive to the antibiotic bleomycin, a dna damaging glycopeptide. a bleomycin resistance determinant, located on transposon tn5 and functional in bacteria, has been cloned in a plant expression vector and introduced into nicotiana plumbaginifolia using agrobacterium tumefaciens. the expression of this determinant in plant cells confers resistance to bleomycin and allows selection of transformed plant cells. | 1986 | 24302302 |
| transformation of medicago by agrobacterium mediated gene transfer. | shoot segments of medicago varia genotype a2 were co-cultivated with agrobacterium tumefaciens strain bo42 carrying pga471, a plasmid coding for the kanamycin resistant determinant as transferable positive selection marker in plant cells (an et al., 1985). resistant plants were regenerated at high frequency from green calli developed on inoculated stem cuttings under kanamycin selection. dna-dna hybridization analysis showed the presence of the structural gene of the kanamycin resistant determin ... | 1986 | 24248043 |
| leaf disc transformation of cultivated tomato (l. esculentum) using agrobacterium tumefaciens. | the leaf disc transformation/regeneration system was modified for tomato (l. esculentum). both leaf explants and cotyledon/hypocotyl sections can be used to regenerate transformed plants. we have obtained over 300 transgenic plants from eight tomato cultivars. we have evidence for both single and multi-copy insertions of the t-dna, and have demonstrated inheritance of the t-dna insert in the expected mendelian ratios. several heterologous promoters function in tomato. a reduced efficiency of tra ... | 1986 | 24248039 |
| shoot regeneration of mesophyll protoplasts transformed by agrobacterium tumefaciens, not achievable with untransformed protoplasts. | alternative methods for shoot regeneration in protoplast derived cultures were developed in nicotiana paniculata and physalis minima. in both species protoplast derived callus is not regeneratable to shoots by conventional methods, e.g. hormone treatment. leaf discs and stem segments of n. paniculata and p. minima were incubated with agrobacterium tumefaciens "shooter" strains harbouring pgv 2215 or pgv 2298 or wildtype strain b6s3. after 36 h of co-incubation protoplasts were prepared. (leaf di ... | 1986 | 24247786 |