Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| a 43-kda nuclear tobacco protein interacts with a specific single-stranded dna sequence from the 5'-upstream region of the agrobacterium rhizogenes rolc gene. | we identified in the nuclear extract of tobacco seedlings a 43-kda dna-binding protein rcs2 that interacted with the 5'-upstream region of the rolc gene of the agrobacterium rhizogenes ri plasmid. dna-protein gel shift and competition assays demonstrated that rcs2 bound to single-stranded dna in a sequence-specific manner. a five-base direct repeat is important for the dna binding of rcs2. south-western blot analysis was employed to determine the size of rcs2 which appears to be approx. 43 kda. | 1994 | 8163189 |
| efficiency of the tetracycline-dependent gene expression system: complete suppression and efficient induction of the rolb phenotype in transgenic plants. | we have investigated the use of the tetracycline-dependent gene expression system to regenerate and propagate tobacco plants transformed with a gene whose product--when highly expressed--interferes with regeneration and/or further reproduction. plants transformed with the agrobacterium rhizogenes rolb gene under the control of the tetracycline-dependent expression system were phenotypically indistinguishable from wild type owing to efficient repression of the promoter. induction of the rolb gene ... | 1994 | 8190069 |
| identification of plant genetic loci involved in a posttranscriptional mechanism for meiotically reversible transgene silencing. | numerous reports describe phenomena of transgene silencing in plants, yet the underlying genetic and molecular mechanisms are poorly understood. we observed that regeneration of arabidopsis thaliana plants transgenic for the rolb gene of agrobacterium rhizogenes results in a selection for transgene silencing. transgene silencing could be monitored in this system by reversion of the visible rolb phenotype. we report a phenotypic, molecular, and genetic characterization of a meiotically reversible ... | 1994 | 8202523 |
| bacterial plant oncogenes: the rol genes' saga. | the rol genes are part of the t-dna which is transferred by agrobacterium rhizogenes in plant cells, causing neoplastic growth and differentiation. each of these bacterial oncogenes deeply influences plant development and is finely regulated once transferred into the plant host. both from the study of the effects and biochemical function of the rol genes and from the analysis of their regulation, important insight in plant development can be derived. some of the most intriguing aspects of past, ... | 1994 | 7896140 |
| rol genes of agrobacterium rhizogenes cucumopine strain: sequence, effects and pattern of expression. | by sequencing the central region of the cucumopine-type t-dna of agrobacterium rhizogenes strain 2659, we identified three open reading frames homologous, to different extents, to orfs 10, 11 and 12 (rola, b and c) of the agropine-type (1855) t-dna. recombinant agrobacterium strains encompassing the orfs of 2659 t-dna--which we refer to as rol alpha, beta and gamma--were utilized to infect carrot discs and to obtain transgenic tobacco plants, in order to compare the morphogenetic capabilities to ... | 1994 | 7948887 |
| alterations of auxin perception in rolb-transformed tobacco protoplasts. time course of rolb mrna expression and increase in auxin sensitivity reveal multiple control by auxin. | expression and physiological effects of the root-inducing rolb gene of agrobacterium rhizogenes t-dna were studied simultaneously in tobacco (nicotiana tabacum) mesophyll protoplasts. the kinetic study of the expression of rolb mrna following exogenous auxin application showed that auxin transiently stimulated rolb expression, with mrna levels starting to accumulate 6 to 9 h after auxin was supplied and increasing 300-fold after 12 to 18 h. the parallel study of the auxin sensitivity of rolb-tra ... | 1994 | 7972494 |
| a new open reading frame, encoding a putative regulatory protein, in agrobacterium rhizogenes t-dna. | we report the presence of an open reading frame, named orf13a, encoding a putative regulatory protein on the t-dna of agrobacterium rhizogenes 8196 ri plasmid. homologous orfs are present at the same location in two other types of ri plasmids. we present evidence that orf13a is transcriptionally active. expression of orf13a was investigated by analysis of glucuronidase (gus) activity in transgenic tobacco containing an orf13agus fusion. the gene fusion was expressed at higher level in roots than ... | 1994 | 7987690 |
| bryonolic acid production in hairy roots of trichosanthes kirilowii max. var japonica kitam. transformed with agrobacterium rhizogenes and its cytotoxic activity. | the hairy roots of trichosanthes kirilowii max, var. japonica kitam. were induced by agrobacterium rhizogenes (tcc 15834) on sterile shoots. the axenic culture of hairy roots proliferated 30 to 60-fold based on the initial fresh weight after three weeks of culture in murashige & skoog liquid media. bryonolic acid as the main triterpenoid was isolated in a high yield, together with chondrillasterol from the hairy roots of this plant. bryonolic acid showed strong inhibition of the growth of b-16 m ... | 1994 | 8004724 |
| sequence of the cellular t-dna in the untransformed genome of nicotiana glauca that is homologous to orfs 13 and 14 of the ri plasmid and analysis of its expression in genetic tumours of n. glauca x n. langsdorffii. | a region homologous to the tl-dna of agrobacterium rhizogenes was previously detected in the genome of untransformed nicotiana glauca and designated cellular t-dna (ct-dna). subsequently, part of this region was sequenced and two genes, which corresponded to rolb and rolc and were named ngrolb and ngrolc, were found. we have now sequenced a region of the ct-dna other than the region that includes ngrolb and c and we have found two other open reading frames (orfs), ngorf13 and ngorf14. these orfs ... | 1994 | 8028588 |
| the rolc promoter of agrobacterium rhizogenes ri plasmid is activated by sucrose in transgenic tobacco plants. | the 5'-upstream region of the rolc gene of the ri plasmid is expressed specifically in phloem cells of transgenic higher plants. in this study, we demonstrated that the rolc promoter is activated by sucrose in phloem cells of transgenic tobacco seedlings bearing rolc promoter-uida chimeric fusion gene. since the rolc promoter is not activated by sorbitol, sucrose metabolism rather than osmotic pressure exerted by the disaccharide may be responsible for induction. thus, experiments using 5'-upstr ... | 1994 | 8041357 |
| changing root system architecture through inhibition of putrescine and feruloyl putrescine accumulation. | plant roots provide anchorage and absorb the water and minerals necessary for photosynthesis in the aerial parts of the plant. since plants are sessile organisms, their root systems must forage for resources in heterogeneous soils through differential branching and elongation [(1988) funct. ecol. 2, 345-351; (1991) plant roots: the hidden half, pp. 3-25, marcel dekker, ny]. adaptation to drought, for instance, can be facilitated by increased root growth and penetration. root systems thus develop ... | 1994 | 8143867 |
| a chimeric gene encoding the methionine-rich 2s albumin of the brazil nut (bertholletia excelsa h.b.k.) is stably expressed and inherited in transgenic grain legumes. | the coding region of the 2s albumin gene of brazil nut (bertholletia excelsa h.b.k.) was completely synthesized, placed under control of the cauliflower mosaic virus (camv) 35s promoter and inserted into the binary vector plasmid pgsgluc1, thus giving rise to pgsgluc1-2s. this was used for transformation of tobacco (nicotiana tabacum l. cv. petit havanna) and of the grain legume vicia narbonensis l., mediated by the supervirulent agrobacterium tumefaciens strain eha 101. putative transformants w ... | 1994 | 8159174 |
| splicing of the rola transcript of agrobacterium rhizogenes in arabidopsis. | the rola gene encoded on the ri plasmid a4 of agrobacterium rhizogenes is one of the transferred (tl-dna) genes involved in the pathogenesis of hairy-root disease in plants. the function of the 100-amino acid protein product of rola is unknown, although its expression causes physiological and developmental alterations in transgenic plants. the rola gene of a. rhizogenes contains an intron in its untranslated leader region that has features typical of plant pre-messenger rna introns. transcriptio ... | 1994 | 7528444 |
| biosynthesis of defense-related proteins in transformed root cultures of trichosanthes kirilowii maxim. var japonicum (kitam.). | we have established transformed ("hairy") root cultures from trichosanthes kirilowii maxim. var japonicum kitam. (cucurbitaceae) and four related species to study the biosynthesis of the ribosome-inactivating protein trichosanthin (tcn) and other root-specific defense-related plant proteins. stable, fast-growing root clones were obtained for each species by infecting in vitro grown plantlets with agrobacterium rhizogenes american type culture collection strain 15834. each species accumulated rep ... | 1994 | 7824645 |
| differentiation of brucella abortus bv. 1, 2, and 4, brucella melitensis, brucella ovis, and brucella suis bv. 1 by pcr. | several pcr assays which identify the genus brucella but do not discriminate among species have been reported. we describe a pcr assay that comprises five oligonucleotide primers which can identify selected biovars of four species of brucella. individual biovars within a species are not differentiated. the assay can identify three biovars (1, 2, and 4) of b. abortus, all three biovars of b. melitensis, biovar 1 of b. suis, and all b. ovis biovars. these biovars include all of the brucella specie ... | 1994 | 7852552 |
| the expression of a chimeric phaseolus vulgaris nodulin 30-gus gene is restricted to the rhizobially infected cells in transgenic lotus corniculatus nodules. | in phaseolus vulgaris there is a nodulin family, npv30, of ca. 30 kda, as detected in an in vitro translation assay [2]. we isolated a gene (npv30-1) for one of the members of this family. the nucleotide sequence of the promoter of npv30-1 contains nodule-specific motifs common to other late nodulin genes. the promoter was fused to the gus reporter gene; this chimeric fusion was introduced into lotus corniculatus via agrobacterium rhizogenes transformation. gus activity was only detected in the ... | 1994 | 7858234 |
| identification of several soybean cytosolic glutamine synthetase transcripts highly or specifically expressed in nodules: expression studies using one of the corresponding genes in transgenic lotus corniculatus. | a dna fragment containing sequences hybridizing to the 5' region of gs15, a gene encoding soybean cytosolic glutamine synthetase, was isolated from a soybean genomic library. mapping and partial sequence analysis of the genomic clone revealed that it encodes a cytosolic gs gene, gs21, which is different from gs15. in parallel, a number of cdna clones encoding cytosolic gs were isolated using the coding region of pgs20 as a probe (pgs20 is a cdna clone which corresponds to a transcript of the gs1 ... | 1995 | 7865779 |
| identification of the agrobacterium tumefaciens c58 t-dna genes e and f and their impact on crown gall tumour formation. | dna sequence analysis of the 4.4 kilobases (kb) eco ri fragment 14 from t-dna of agrobacterium tumefaciens c58 revealed three open reading frames. one of them (945 bp) was supposed to encode the transcript e, the function of which has not been identified to date. furthermore, a so far undescribed open reading frame (1035 bp) was identified, located in the centre of the eco ri fragment 14 and termed gene f. the third open reading frame encoded the carboxy-terminal part of the agrocinopine synthas ... | 1995 | 7865795 |
| a new agrobacterium strain isolated from aerial tumors on ficus benjamina l. | crown gall tumors, collected from branches of 1-year-old weeping fig (ficus benjamina l.) trees, yielded both tumorigenic and nonpathogenic agrobacteria. on the basis of classical diagnostic tests, the nonpathogenic strains were identified as agrobacterium tumefaciens, whereas the tumorigenic strains could not be assigned to any of the known terrestrial agrobacterium spp. the tumorigenic strains also differed from other members of the genus by producing more acid from mannitol. according to clus ... | 1995 | 7887626 |
| analysis of the lupin nodulin-45 promoter: conserved regulatory sequences are important for promoter activity. | the promoter from the lupinus angustifolius late nodulin gene, nodulin-45, has been analysed to identify cis-elements and trans-acting factors. various regions of the nodulin-45 promoter, fused to the luciferase reporter gene, were introduced into lotus roots using an agrobacterium rhizogenes, transformation procedure. the transgenic roots were then nodulated. the promoter region a (-172 to +13, relative to the transcription start site) was capable of directing low-level expression of the report ... | 1995 | 7894011 |
| taxonomic study of bacteria isolated from plants: proposal of sphingomonas rosa sp. nov., sphingomonas pruni sp. nov., sphingomonas asaccharolytica sp. nov., and sphingomonas mali sp. nov. | the taxonomic positions of 10 strains of 3-ketolactose-forming bacteria which were isolated from the roots of plants (rosa sp., psychotria nairobiensis, ardisia crispa, prunus persica, and apple trees) were investigated. the dna base compositions of these strains ranged from 64.0 to 65.7 mol%, the isoprenoid quinone of each strain was ubiquinone 10, 3-hydroxy fatty acids were lacking in the cellular fatty acids of these organisms, and all of the strains contained a sphingolipid with the long-cha ... | 1995 | 7537068 |
| a 200 bp region of the pea enod12 promoter is sufficient for nodule-specific and nod factor induced expression. | enod12 is one of the first nodulin genes expressed upon inoculation with rhizobium and also purified nod factors are able to induce enod12 expression. the enod12 gene family in pea (pisum sativum) has two members. a cdna clone representing psenod12a [26] and a psenod12b genomic clone [7] have been previously described. the isolation and characterization of a psenod12a genomic clone is presented in this paper. by using a vicia hirsuta-agrobacterium rhizogenes transformation system it is shown tha ... | 1995 | 7548827 |
| identification of rhizobium-specific intergenic mosaic elements within an essential two-component regulatory system of rhizobium species. | analysis of the dna regions upstream of the phosphoenolpyruvate carboxykinase gene (pcka) in rhizobium meliloti and rhizobium sp. strain ngr234 identified an open reading frame which was highly homologous to the agrobacterium tumefaciens chromosomal virulence gene product chvi. a second gene product, 500 bp downstream of the chvi-like gene in r. meliloti, was homologous to the a. tumefaciens chvg protein. the homology between the r. meliloti and a. tumefaciens genes was confirmed, because the r. ... | 1995 | 7559334 |
| evaluation in tobacco of the organ specificity and strength of the rold promoter, domain a of the 35s promoter and the 35s2 promoter. | in order to study the expression in plants of the rold promoter of agrobacterium rhizogenes, we have constructed chimaeric genes placing the coding region of the gusa (uida) marker gene under control of two rold promoter fragments of different length. similar results were obtained with both genes. expression studies were carried out in transformed r1 progeny plants. in mature transformed tobacco plants, the rold-gus genes were expressed strongly in roots, and to much lower levels in stems and le ... | 1995 | 7581519 |
| the plant oncogenes rola, b, and c from agrobacterium rhizogenes. effects on morphology, development, and hormone metabolism. | 1995 | 7581667 | |
| quantifying polyamines in agrobacterium rhizogenes strains and in ri plasmid transformed cells. | 1995 | 7581668 | |
| universal pcr primers for detection of phytopathogenic agrobacterium strains. | two pcr primer pairs, based on the vird2 and ipt genes, detected a wide variety of pathogenic agrobacterium strains. the endonuclease domain of vird2 protein, which cleaves transferred dna (t-dna) border sequences, is highly conserved; primer oligonucleotides specific for the endonuclease portion of vird2 detected all pathogenic strains of agrobacterium tested. pcr primers corresponding to conserved sequences in ipt, the t-dna-borne cytokinin synthesis gene, detected only agrobacterium tumefacie ... | 1995 | 7487020 |
| horizontal gene transfer: regulated expression of a tobacco homologue of the agrobacterium rhizogenes rolc gene. | a tobacco homologue (trolc) of the rolc gene of the agrobacterium rhizogenes ri-plasmid was cloned and sequenced from nicotiana tabacum l. cv. havana 425. the coding region of trolc is similar in sequence (69-87% for dna and 54-89% for the deduced amino acid sequence) to rolc genes of the agropine, mannopine, and mikimopine strains of ri-plasmids and the n. glauca rolc homologue. southern analyses showed that trolc is encoded by a small gene family derived from the tomentosiformis ancestor of to ... | 1995 | 7500950 |
| the regulatory functions of the rolb and rolc genes of agrobacterium rhizogenes are conserved in the homologous genes (ngrol) of nicotiana glauca in tobacco genetic tumors. | to compare patterns of expression between the ngrol genes of n. glauca and the rirol genes of agrobacterium rhizogenes, we performed fluorometric and histochemical analysis of transgenic genetic tumors on the hybrid of nicotiana glauca x n. langsdorffii (f1) that harbored a beta-glucuronidase (gus) reporter gene fused to the promoter of ngrolb, ngrolc, rirolb or rirolc. the promoters of ngrolb and ngrolc had 2- to 3-fold lower activity than those of rirolb and rirolc. however, the changes in pat ... | 1995 | 8528603 |
| the promoter of the vicia faba l. vfenod-grp3 gene encoding a glycine-rich early nodulin mediates a predominant gene expression in the interzone ii-iii region of transgenic vicia hirsuta root nodules. | we recently reported on the broad bean gene vfenod-grp3 encoding a glycine-rich early nodulin. this gene was predominantly expressed in the interzone ii-iii region of vicia faba root nodules. the vfenod-grp3 promoter contained several sequence motifs potentially involved in the regulation of gene expression. to investigate the molecular basis for the specific vfenod-grp3 expression, defined vfenod-grp3 promoter fragments were fused to an intron-containing gusaint gene. agrobacterium rhizogenes a ... | 1995 | 8541502 |
| agrobacterium rhizogenes as a vector for transforming higher plants. application in lotus corniculatus transformation. | 1995 | 8563829 | |
| hairy root nodulation of casuarina glauca: a system for the study of symbiotic gene expression in an actinorhizal tree. | the purpose of this study was to establish a fast system for producing transgenic actinorhizal root nodules of casuarina glauca. agrobacterium rhizogenes strain a4rs carrying the p35s-gusa-int gene construct was used to induce hairy roots on hypocotyls of 3-week-old c. glauca seedlings. three weeks after wounding, the original root system was excised, and composite plants consisting of transgenic roots on untransformed shoots were transferred to test tubes to be inoculated with frankia. the acti ... | 1995 | 8589409 |
| flow sorting of the y sex chromosome in the dioecious plant melandrium album. | the preparation of stable chromosome suspensions and flow cytometric sorting of both the y sex chromosome of the white campion, melandrium album, and the deleted y chromosome of an asexual mutant, 5k63, is described. the principle has been to maintain transformed roots in vitro, synchronise and block mitosis, reduce cells to protoplasts, and lyse these to release chromosomes. such in vitro material, unlike many cell suspensions, showed a stable karyotype. factors critical to producing high-quali ... | 1995 | 8608734 |
| hairy root culture of artemisia annua l. by ri plasmid transformation and biosynthesis of artemisinin. | the hairy root culture system of the medical plant artemisia annua l. was established by infection with agrobacterium rhizogenes r1601. the transgenic state of transformed roots was confirmed by southern blot hybridization with tl-dna of pfw302. the expression of nptii gene was confirmed by enzymic assay. the important secondary metabolites-artemisinin was obtained in the hairy root culture. the effects of various physical and chemical factors on the growth of the hairy roots and production of a ... | 1995 | 8739100 |
| impaired photoassimilate partitioning caused by phloem-specific removal of pyrophosphate can be complemented by a phloem-specific cytosolic yeast-derived invertase in transgenic plants. | constitutive expression of the escherichia coli ppa gene encoding inorganic pyrophosphatase resulted in sugar accumulation in source leaves and stunted growth of transgenic tobacco plants. the reason for this phenotype was hypothesized to be reduced sucrose utilization and loading into the phloem. to study the role of ppi in phloem cells, a chimeric gene was constructed using the phloem-specific rolc promoter of agrobacterium rhizogenes to drive the expression of the ppa gene. removal of cytosol ... | 1995 | 7734961 |
| expression of agrobacterium rhizogenes auxin biosynthesis genes in transgenic tobacco plants. | plant oncogenes aux1 and aux2 carried by the tr-dna of agrobacterium rhizogenes strain a4 encode two enzymes involved in the auxin biosynthesis pathway in transformed plant cells. the short divergent promoter region between the two aux-coding sequences contains the main regulatory elements. this region was fused to the uida reporter gene and introduced into nicotiana tabacum in order to investigate the regulation and the tissue specificity of these genes. neither wound nor hormone induction coul ... | 1995 | 7787177 |
| isolation and characterization of mutants of thiophene synthesis in tagetes erecta. | two mutants of tagetes erecta displaying aberrant thiophene composition were identified by screening more than 300 plants from a mutagenized m2 population using high-performance liquid chromatography analysis of root extracts. both mutants, which may have originated from the same mutational event, contained high amounts of the c13 monothiophene 2-(but-3-en-1-ynyl)-5-(penta-1,3-diynyl)-thiophene that was previously not found in t. erecta and also high amounts of two c13 bithienyls that were absen ... | 1995 | 12228405 |
| infection of hairy roots of strawberry (fragaria x ananassa duch.) with arbuscular mycorrhizal fungus. | hairy root cultures of strawberry (fragaria x ananassa duch.) were induced with the agrobacterium rhizogenes strain a4. cultures were maintained on b50 medium but could also grow on a minimal medium, which did not inhibit the growth of arbuscular mycorrhizal fungi. the growth and nutrient uptake were characterized in shake flasks and in a bioreactor. spores of the native finnish arbuscular mycorrhizal fungus glomus fistulosum v128 were used to infect strawberry (fragaria x ananassa duch. 'senga ... | 1995 | 24185521 |
| agrobacterium rhizogenes rol genes induce productivity-related phenotypical modifications in "creeping-rooted" alfalfa types. | agrobacterium rhizogenes rol genes were transferred individually or in combination into the forage legume medicago sativa l. (alfalfa). kanamycin resistant, neomycin phosphotransferase ii positive plants showed the presence of the rol inserts in their genome. phenotypical evaluation of transgenic populations indicated significant morphological alterations of the root system, stem number per plant and plant structure. a possible utilization of these transgenics in breeding programs of the so-call ... | 1995 | 24185517 |
| growth and steroidal saponin production in hairy root cultures of solanum aculeatissimum. | hairy root cultures of solanum aculeatissimum were established by trans-formation using agrobacterium rhizogenes strain 15834. root growth and production of steroidal saponin were investigated under various culture conditions. transformed roots grew better in gamborg's b5 medium containing 3 % sucrose under continuous light than in the dark. also, the roots turned light green when cultured under continuous light. green hairy roots produced aculeatiside a (6.71mg ·) l(-1) and aculeatiside b (6.39 ... | 1995 | 24185447 |
| a novel life cycle arising from leaf segments in plants regenerated from horseradish hairy roots. | horseradish (armoracia rusticana) hairy root clones were established from hairy roots which were transformed with the ri plasmid in agrobacterium rhizogenes 15834. the transformed plants, which were regenerated from hairy root clones, had thicker roots with extensive lateral branches and thicker stems, and grew faster compared with non-transformed horseradish plants. small sections of leaves of the transformed plants generated adventitious roots in phytohormone-free g (modified gamborg's) medium ... | 1995 | 24185335 |
| production of valepotriates by hairy root cultures of centranthus ruber dc. | hairy root cultures of centranthus ruber dc. were established by infection of sterile plantlets with agrobacterium rhizogenes, strain r1601. the transformed roots were grown in 12 different, hormone-free liquid media, and valtrate, isovaltrate, 7-desisovaleroyl-7-acetylvaltrate, 7-homovaltrate, didrovaltrate and isovaleroxyhydroxydidrovaltrate were quantified by high performance liquid chromatography. the highest overall valepotriate content (3.0% dry wt) was observed in half-strength gamborg b5 ... | 1995 | 24186763 |
| virulence of different agrobacterium strains on hairy root formation of hyoscyamus muticus. | hyoscyamus muticus accession was evaluated for its response to inoculation with agrobacterium rhizogenes strains lba9402, a4, 15834, and agrobacterium tumefaciens strain c58 ci prt gus104. the agrobacterium strain used for the transformation has a significant influence on the phenotype of the clone as well as on the growth rate and hyoscyamine production of these root culture clones. the most virulent strains were c58 ci prt gus104 and lba9402. more roots were obtained on lso medium than on b50 ... | 1995 | 24190302 |
| improvements in rooting regenerated safflower (carthamus tinctorius l.) shoots. | a continuing obstacle for regenerating safflower (carthamus tinctorius l.) plants from cultured explants or callus has been a reliable method for rooting shoots. for shoots directly regenerated from primary explants, 76% of shoots rooted after a 7-d exposure to 10 mg/1 indole-3-butyric acid. auxin source, concentration or exposure time did not greatly affect root formation or morphology, but strongly affected callus production. shoots infected with agrobacterium rhizogenes produced massive numbe ... | 1996 | 24178666 |
| agrobacterium rhizogenes-mediated dna transfer inpinus halepensis mill. | agrobacterium rhizogenes strain lba9402 was used to transformpinus halepensis embryos, seedlings and shoots. mature embryos exhibited susceptibility to the agrobacterium as monitored by β-glucurortidase (gus) expression, with more than 85% showing considerable transient gus expression in the radicle. gus expression was also observed in cotyledons, but at a lower rate of about 24% of the embryos (1-5 spots/embryo). stable transformation was evidenced by the regeneration of gus-expressing roots an ... | 1996 | 24178648 |
| production of ribosome-inactivating protein from hairy root cultures of luffa cylindrica (l.) roem. | transformed root lines of luffa cylindrica (l.) roem. (cucurbitaceae) were established by inoculation of in vitro grown plantlets with wild type agrobacterium rhizogenes strain 1855. cloned lines of hairy roots were tested for the presence of ribosome-inactivating proteins; crude extracts inhibited protein synthesis in a reaction mixture based on rabbit reticulocyte lysate. inhibitory activity increased during culture period, reaching a maximum value in the stationary phase. no activity could be ... | 1996 | 24178273 |
| in vitro propagation of cashewnut. | in vitro plant propagation was developed for seedling shoot tips, leaf axils, and cotyledonary nodes of cashew, anacardium occidentale. factors affecting multiplication rate included age of explant source, explant type, medium composition, light requirements, and transfer frequency. cotyledonary nodes produced more buds than other explant types. nodes had a 90% viability when transferred daily to fresh medium containing activated charcoal for 7 d while exposed to continuous dark. cultures were t ... | 1996 | 24178529 |
| increase of root induction in pinus nigra explants using agrobacteria. | wounding of explanted pinus nigra primary explants followed by infection with agrobacterium rhizogenes wild strains 8196, 15834, or with the pria4abc transconjugant strain of a. tumefaciens (c58 chromosomal background) resulted in adventitious root induction. roots were formed in 60-97% of explants (1-3 roots/explant) but without a hairy root phenotype. the presence of t-dna of pri8196 or pria4abc in regenerated roots was confirmed by the opine (mannopinic acid) content. transformation response ... | 1996 | 24178528 |
| highly efficient transformation and regeneration of aspen plants through shoot-bud formation in root culture. | the natural capacity of aspen (populus tremula l.) roots for direct shoot-bud regeneration was harnessed to establish a highly efficient transformation and regeneration procedure that does not require a pre-selection stage on antibiotics. aspen stem segments were transformed using wildtype agrobacterium rhizogenes (lba9402) with the binary p35sgusint plasmid carrying the genes coding for β-glucuronidase (gus) and neomycin phosphotransferase ii. high levels of transient gus expression were found ... | 1996 | 24178519 |
| traits of panax ginseng hairy roots after cold storage and cryopreservation. | panax ginseng hairy root cultures were established by infecting petiole segments with agrobacterium rhizogenes strain 15834. hairy root segments including root tips placed onto phytohormone-free 1/2 murashige and skoog solid medium and stored at 4 °c in the dark for 4 months, resumed elongation when the temperature was raised to 25 °c in the dark. for cryopreservation, a vitrification method was applied. root tips precultured with 0.1 mg/l 2,4-d for 3 days and dehydrated with pvs2 solution for 8 ... | 1996 | 24178517 |
| establishment of transformed root cultures of perezia cuernavacana producing the sesquiterpene quinone perezone. | the sesquiterpene quinone currently known as perezone is abundantly produced by the roots of perezia cuernavacana. this compound is of biotechnological interest since it may be used as a pigment and has several pharmacological properties. in this work we demonstrate that perezone is also produced in transformed root cultures of p. cuernavacana. hairy roots were induced by inoculation of internodal segments of sterile plants of p. cuernavacana with agrobacterium rhizogenes ar12 strain. the axenic ... | 1996 | 24178452 |
| withanolide composition and in vitro culture of italian withania somnifera. | from italian plants of withania somnifera six withanolides were isolated, whose structures allowed us to assign the italian race of w. somnifera to the israel chemotype iii. in vitro cultures of italian w. somnifera under different conditions were obtained, as well as infection by agrobacterium rhizogenes. hplc analysis of in vitro derived tissues showed low contents of withanolides. | 1996 | 17252448 |
| withanolide production by root cultures of withania somnifera transformed with agrobacterium rhizogenes. | transformed root cultures of withania somnifera dunal (solanaceae) were obtained by infecting shoots cultured in vitro with agrobacterium rhizogenes lba 9402. they grew axenically in the absence of exogenous plant growth regulators in murashige and skoog's medium containing 3% (w/v) sucrose. the root cultures synthesized several withanolides of which withanolide d was isolated and identified. transformed root (clone hr (1)) showed a growth index of 20.07 and a withanolide d yield of 0.30 mg g(-1 ... | 1996 | 17252504 |
| amyloplast distribution in hairy roots induced by infection with agrobacterium rhizogenes. | to elucidate the rapid and plagiotropic growth of hairy root induced by a. rhizogenes, a root apex was investigated with respect to it's amyloplast deposition, activity of alpha-amylase and glucose content. the amyloplasts distributed in the hairy roots were fewer than those of the adventitious root. since auxin availability is enhanced in hairy roots, it could affect the statolith degradation by elevating alpha-amylase activity so that the energy requirement for rapid growth could be fulfilled ... | 1996 | 11785535 |
| attenuation of the phenotype caused by the root-inducing, left-hand, transferred dna and its rola gene (correlations with changes in polyamine metabolism and dna methylation). | we present four examples of attenuation of the transformed phenotype caused by the root-inducing, left-hand, transferred dna from agrobacterium rhizogenes in tobacco (nicotiana tabacum). the first was associated with a genetic variable (homozygosity for the t-dna), and the second was induced at the physiological level by putrescine and tyramine, suggesting that the transformed phenotype depends on defective polyamine metabolism. physiological attenuation is further illustrated in the third examp ... | 1996 | 12226290 |
| expression of the agrobacterium rhizogenes rolc gene in a deciduous forest tree alters growth and development and leads to stem fasciation. | we have altered the growth and development of a deciduous forest tree by transforming hybrid aspen (populus tremula x populus tremuloides) with the agrobacterium rhizogenes rolc gene expressed under the strong cauliflower mosaic virus 35s promoter. we demonstrate that the genetically manipulated perennial plants, after a period of dormancy, maintain the induced phenotypical changes during the second growing period. furthermore, mass-spectrometrical quantifications of the free and conjugated form ... | 1996 | 12226405 |
| the response to auxin of rapeseed (brassica napus l.) roots displaying reduced gravitropism due to transformation by agrobacterium rhizogenes. | it has recently been documented that, compared to untransformed controls, the roots of oilseed rape (brassica napus l. cv crgc5) seedlings transformed by agrobacterium rhizogenes a4 show a reduced gravitropic reaction (legue et al. 1994, physiol plant 91: 559-566). after stimulation at 90 degrees c or 135 degrees, the transformed root tips curve. but never reach a vertical orientation. in the present study, we investigated the causes of reduced gravitropic bending observed in stimulated transfor ... | 1996 | 11540728 |
| expression of two heterologous promoters, agrobacterium rhizogenes rolc and cauliflower mosaic virus 35s, in the stem of transgenic hybrid aspen plants during the annual cycle of growth and dormancy. | we monitored, for the first time, the activity of two model heterologous promoters, the agrobacterium rhizogenes rolc and the cauliflower mosaic virus (camv) 35s, throughout the annual cycle of growth and dormancy in a perennial species, hybrid aspen. each promoter was fused to the uida beta-glucuronidase (gus) reporter gene and the constructs were introduced into the hybrid aspen genome by agrobacterium-mediated transformation. both wild-type and transgenic plants were cultivated under differen ... | 1996 | 8806418 |
| the plant oncogene rold stimulates flowering in transgenic tobacco plants. | the agrobacterium rhizogenes t-dna oncogene rold under the control of its own 5' regulatory region was transferred to day-neutral tobacco plants. the main trait induced by rold in transgenic plants is a striking precocity in flower setting and a strong enhancement of the flowering potential. in rold plants, early flowering is followed by the very rapid growth of numerous lateral inflorescences. the analysis of several morphological and histological parameters suggests that some characteristic mo ... | 1996 | 8954737 |
| tissue-specific expression of the rola gene mediates morphological changes in transgenic tobacco. | the spatial and temporal activity of the entire and individual promoter domains of the rola gene of agrobacterium rhizogenes was investigated and correlated with the distinctive features of the phenotypes of transgenic tobacco plants. the gus assay was performed in the presence of an oxidative catalyst during the development of transgenic plants expressing chimeric genes containing the beta-glucuronidase coding sequence under the control of the different promoter domains. in situ hybridization w ... | 1996 | 8616229 |
| expression patterns of vascular-specific promoters rolc and sh in transgenic potatoes and their use in engineering plrv-resistant plants. | the expression patterns of gus fusion constructs driven by the agrobacterium rhizogenes rolc and the maize sh (shrunken; sucrose synthase-1) promoters were examined in transgenic potatoes (cv. atlantic). rolc drove high-level gene expression in phloem tissue, bundle sheath cells and vascular parenchyma, but not in xylem or non-vascular tissues. sh expression was exclusively confined to phloem tissue. potato leafroll luteovirus (plrv) replicates only in phloem tissues, and we show that when rolc ... | 1997 | 9132064 |
| wound-inducible and organ-specific expression of orf13 from agrobacterium rhizogenes 8196 t-dna in transgenic tobacco plants. | tissue-specific expression of the orf13 promoter from agrobacterium rhizogenes 8196 was assessed throughout the development of transgenic tobacco plants using a gus reporter gene. orf13 exhibited high activity in roots but with different patterns of expression. the activity of the orf13 promoter in vascular tissues increased from the base to the tip of the stem. the orf13 promoter is wound inducible in a limited area adjacent to the wound site. the time course of wound induction of orf13 in tran ... | 1997 | 9150269 |
| overexpression of a soybean gene encoding cytosolic glutamine synthetase in shoots of transgenic lotus corniculatus l. plants triggers changes in ammonium assimilation and plant development. | a soybean cytosolic glutamine synthetase gene (gs15) was fused with the constitutive 35s cauliflower mosaic virus (camv) promoter in order to direct overexpression in lotus corniculatus l. plants. following transformation with agrobacterium rhizogenes, eight independent lotus transformants were obtained which synthesized additional cytosolic glutamine synthetase (gs) in the shoots. to eliminate any interference caused by the t-dna from the ri plasmid, three primary transformants were crossed wit ... | 1997 | 9151446 |
| mutational analysis of the rola gene of agrobacterium rhizogenes in tobacco: function of the rola pre-mrna intron and rola proteins defective in their biological activity. | the rola gene of agrobacterium rhizogenes contains in its untranslated leader region a spliceosomal intron, which is spliced in arabidopsis and in nicotiana tabacum. expression under the control of the 35s promoter from cauliflower mosaic virus of a rola gene derivative defective in splicing still causes alterations of growth in transgenic tobacco plants. splicing of rola mrna is required for efficient expression of the rola phenotype in vivo. moreover, splicing is required for efficient in vitr ... | 1997 | 9164171 |
| differential modification of flavonoid and isoflavonoid biosynthesis with an antisense chalcone synthase construct in transgenic lotus corniculatus. | three clonal genotypes of lotus corniculatus l. (bird's foot trefoil) were transformed with an antisense chalcone synthase (chs) gene construct made using a stress induced chs17 cdna from phaseolus vulgaris under the control of the constitutive camv 35s promoter and nos terminator via agrobacterium rhizogenes. after initial screening, ten antisense and five control co-transformation events from each recipient clonal genotype were analysed. after elicitation with glutathione, the level of tannin ... | 1997 | 9349273 |
| expression of glyoxylate cycle genes in cucumber roots responds to sugar supply and can be activated by shading or defoliation of the shoot. | when cucumber roots are excised and incubated without a carbon source, isocitrate lyase (icl) and malate synthase (ms) mrnas increase significantly in amount. however, if sucrose is added to the excised roots, the mrnas do not accumulate. hairy roots obtained by transformation with agrobacterium rhizogenes show the same response. transgenic hairy roots containing the icl and ms gene promoters fused to the gus reporter gene, have very low gus activity which increases dramatically when roots are i ... | 1997 | 9349284 |
| a binary-bac system for plant transformation with high-molecular-weight dna. | a binary-bac (bibac) vector suitable for agrobacterium-mediated plant transformation with high-molecular-weight dna was constructed. a bibac vector is based on the bacterial artificial chromosome (bac) library vector and is also a binary vector for agrobacterium-mediated plant transformation. the bibac vector has the minimal origin region of the escherichia coli f plasmid and the minimal origin of replication of the agrobacterium rhizogenes ri plasmid, and thus replicates as a single-copy plasmi ... | 1997 | 9373144 |
| pattern of dna binding of nuclear proteins to the proximal agrobacterium rhizogenes rolc promoter is altered during somatic embryogenesis of carrot. | carrot cells cultured in vitro in a medium supplemented with 2,4-d (2,4-dichlorophenoxyacetic acid) proliferate as unorganized cell clusters. upon removal of 2,4-d from the culture medium, these cells undergo somatic embryo formation through globular, heart, and torpedo stages. since the proximal -255 bp upstream region of the rolc gene of the ri plasmid confers somatic embryogenesis-related activation on the uida gene in transgenic carrot cell culture, we investigated the interaction of nuclear ... | 1997 | 9409771 |
| rolb expression pattern in the early stages of carrot somatic embryogenesis. | the pattern of expression of the rolb gene, derived from the t-dna of the plant pathogen agrobacterium rhizogenes, has been investigated during the early stages of somatic embryo formation in suspension cultures of carrot (daucus carota l.). the reporter gene gus (escherichia coli beta-glucuronidase), under transcriptional control of full-length rolb promoter region, has been utilized in order to evaluate both qualitative and quantitative variations in the expression pattern. fluorimetric measur ... | 1997 | 9570894 |
| agravitropic behaviour of roots of rapeseed (brassica napus l.) transformed by agrobacterium rhizogenes. | transgenic hairy roots of brassica napus (cv. omega) have been developed, using agrobacterium rhizogenes strain ar 25, for use as a model system in the investigation of physiological and morphological differences between transgenic and normal roots. the basic parameters of growth and normal or altered gravitropical behaviour of hairy roots are for the first time presented in this paper together with an ultrastructural and morphological analysis of the root statocytes. the results obtained also r ... | 1997 | 11541870 |
| agrobacterium rhizogenes-mediated transformation of artemisia annua: production of transgenic plants. | transgenic hairy roots were induced in the leaves of artemisia annua by treatment with the lba 9402 strain of agrobacterium rhizogenes. the axenic hairy root cultures were found to produce the sesquiterpenes artemisinic acid and arteannuin b. the hairy root cultures were observed to spontaneously regenerate into plantlets on solid hormone-free ms medium. the regenerated plants had phenotypic characteristics typical to the transformed plants. among the plants of the age of one month in culture, t ... | 1997 | 17252369 |
| production of monoclonal antibodies by tobacco hairy roots. | hairy roots of tobacco (nicotiana tabacum) were used to produce full-length murine lgg(1) monoclonal antibody. the presence of heavy (gamma) and light (kappa) chains and fully assembled antibody was verified by western blot analysis of root extracts. antibody levels in the biomass and medium were quantified by elisa based on detection of gamma-kappa complexes. antibody produced by hairy roots was fully functional as demonstrated in bacterial aggregation assays which confirmed bivalent antigen-bi ... | 1997 | 18634133 |
| insertion sequences. | insertion sequences (iss) constitute an important component of most bacterial genomes. over 500 individual iss have been described in the literature to date, and many more are being discovered in the ongoing prokaryotic and eukaryotic genome-sequencing projects. the last 10 years have also seen some striking advances in our understanding of the transposition process itself. not least of these has been the development of various in vitro transposition systems for both prokaryotic and eukaryotic e ... | 1998 | 9729608 |
| analysis of stable low-molecular-weight rna profiles of members of the family rhizobiaceae. | staircase electrophoresis in polyacrylamide gels was used to analyze the stable low-molecular-weight (lmw) rna profiles of 24 type strains belonging to the family rhizobiaceae. this new electrophoretic technique results in good separation of the molecules forming the lmw rna profiles. differences in the number and distribution of the rna bands in these profiles allowed us to identify differences among the 24 strains assayed. species assignments based on lmw rnas proved to be consistent with the ... | 1998 | 9575134 |
| auxin-growth relationships in maize coleoptiles and pea internodes and control by auxin of the tissue sensitivity to auxin | growth of a zone of maize (zea mays l.) coleoptiles and pea (pisum sativum l.) internodes was greatly suppressed when the organ was decapitated or ringed at an upper position with the auxin transport inhibitor n-1-naphthylphthalamic acid (npa) mixed with lanolin. the transport of apically applied 3h-labeled indole-3-acetic acid (iaa) was similarly inhibited by npa. the growth suppressed by npa or decapitation was restored by the iaa mixed with lanolin and applied directly to the zone, and the ma ... | 1998 | 9701602 |
| release of epigenetic gene silencing by trans-acting mutations in arabidopsis. | gene silencing in plants inactivates trans-genes introduced into plants and/or endogenous homologous genes. this stable but potentially reversible loss of gene activity resembles epigenetic changes that occur in normal development. the stability of silencing implies the involvement of trans-acting components, although none of them have been identified so far. here we report the finding of second-site mutations interfering with maintenance of the silent state. we mutagenized arabidopsis thaliana ... | 1998 | 10939915 |
| mapping the functional roles of cap cells in the response of arabidopsis primary roots to gravity. | the cap is widely accepted to be the site of gravity sensing in roots because removal of the cap abolishes root curvature. circumstantial evidence favors the columella cells as the gravisensory cells because amyloplasts (and often other cellular components) are polarized with respect to the gravity vector. however, there has been no functional confirmation of their role. to address this problem, we used laser ablation to remove defined cells in the cap of arabidopsis primary roots and quantified ... | 1998 | 9449842 |
| studies on dynamics of growth and biosynthesis of artemisinin in hairy roots of artemisia annua l. | seven hairy root lines with the properties of fast growth and high artemisinin contents were selected from 747 hairy roots induced by transformation of artemisia annua l. strain 025 with agrobacterium rhizogenes atcc15834. the differences of growth rates and artemisinin contents among the 7 selected hairy root lines were extremely significant, of which hr-9 gave the highest yield of artemisinin, reaching 33.25 mg/y.l. the differences of growth rates and artemisinin contents among hairy roots, un ... | 1998 | 10503642 |
| [anthraquinone production and analysis in the hairy root cultures of rheum palmatum l]. | hairy root culture of the medicinal plant rheum palmatum l. was established by genetic transformation with agrobacterium rhizogenes. the effects of various media with different ph on growth of the hairy roots and biosynthesis of free anthraquinones were investigated. the experimental results showed that ms agar medium with ph 5.5-5.8 is suitable for growth of the hairy roots. dark condition is favourable and 62.5-fold increase in fresh weight was reached within a culture period of 25 days. auxin ... | 1998 | 12016951 |
| anthraquinones from hairy root cultures of cassia obtusifolia. | hairy root cultures of cassia obtusifolia clones transformed with agrobacterium rhizogenes strain 9402 were established to investigate the anthraquinone production. seven anthraquinones, together with betulinic acid, stigmasterol and sitosterol were isolated from the hairy roots. their chemical structures were elucidated on the basis of chromatographic and spectral data. the effects of culture conditions and rare earth element eu(3+) on the production of six free anthraquinones have also been in ... | 1998 | 11711074 |
| terpenoids in transformed root culture of tripterygium wilfordii. | investigation of a hairy root culture of tripterygium wilfordii var. regelii transformed with agrobacterium rhizogenes resulted in the isolation of new diterpenoid and sesquiterpenoid together with known triterpenoids. these structures were determined by spectroscopic analyses. | 1998 | 11711110 |
| unconventional genomic organization in the alpha subgroup of the proteobacteria. | pulsed-field gel electrophoresis was used to analyze the genomic organization of 16 bacteria belonging or related to the family rhizobiaceae of the alpha subgroup of the class proteobacteria. the number and sizes of replicons were determined by separating nondigested dna. hybridization of an rrn gene probe was used to distinguish between chromosomes and plasmids. members of the genus agrobacterium all possess two chromosomes, and each biovar has a specific genome size. as previously demonstrated ... | 1998 | 9573163 |
| suppression of o-methyltransferase gene by homologous sense transgene in quaking aspen causes red-brown wood phenotypes | homologous sense suppression of a gene encoding lignin pathway caffeic acid o-methyltransferase (caomt) in the xylem of quaking aspen (populus tremuloides michx.) resulted in transgenic plants exhibiting novel phenotypes with either mottled or complete red-brown coloration in their woody stems. these phenotypes appeared in all independent transgenic lines regenerated with a sense caomt construct but were absent from all plants produced with antisense caomt. the caomt sense transgene expression w ... | 1998 | 9576779 |
| root colonization by agrobacterium tumefaciens is reduced in cel, attb, attd, and attr mutants. | root colonization by agrobacterium tumefaciens was measured by using tomato and arabidopsis thaliana roots dipped in a bacterial suspension and planted in soil. wild-type bacteria showed extensive growth on tomato roots; the number of bacteria increased from 10(3) bacteria/cm of root length at the time of inoculation to more than 10(7) bacteria/cm after 10 days. the numbers of cellulose-minus and nonattaching attb, attd, and attr mutant bacteria were less than 1/10,000th the number of wild-type ... | 1998 | 9647796 |
| a simple method for the production of highly competent cells of agrobacterium for transformation via electroporation. | the introduction of binary plasmids into agrobacterium hosts for agrobacterium-mediated transformation of plants is most readily achieved by electroporation. however, occasionally, no transformed colonies are recovered and the transformation program is delayed. poor transformation rates are commonly associated with particular combinations of agrobacterium strains and plasmid-selection markers. in order to avoid this problem, it is important for the bacteria to have a highly competent status for ... | 1998 | 9658392 |
| structural characterization of the virb operon on the hairy-root-inducing plasmid a4. | the hairy-root-inducing plasmid a4 (pria4) is capable of conferring tumorigenic symptoms on plants upon infection by its host bacterium, agrobacterium rhizogenes. the virb operon on pria4 has been sequenced and found to be composed of 11 genes, virb1 to virb11, whose products mostly appear to be associated with the cell membrane. a novel structural characteristic is frequent overlappings between the translation termination and initiation codons of adjacent genes. this is indicative of fine tunin ... | 1998 | 9679196 |
| mspg3, a medicago sativa polygalacturonase gene expressed during the alfalfa-rhizobium meliloti interaction. | polygalacturonase (pg) is one of the most important enzymes associated with plant cell wall degradation. it has been proposed to participate in the early steps of the rhizobium-legume interaction. we have identified two classes of cdna fragments corresponding to two classes of pg genes in the medicago genome. one of this class, represented by e2 in m. truncatula and pl1 in m. sativa, seems to be related to previously characterized plant pg genes expressed in pollen. we have isolated the genomic ... | 1998 | 9689142 |
| peroxidase production in vitro by armoracia lapathifolia (horseradish)-transformed root cultures: effect of elicitation on level and profile of isoenzymes. | transformed roots of armoracia lapathifolia (horseradish) were established by infection with agrobacterium rhizogenes lba 9402. they were used as a culture system in vitro for peroxidase production in vitro, to avoid many of the problems that affect the traditional production from field-grown species of armoracia sp. the time course of growth of these cultures showed that total peroxidase attained maximum levels at the end of the exponential growth phase. at this stage of culture, elicitation as ... | 1998 | 9693086 |
| modified development in transgenic tobacco plants expressing a rola::gus translational fusion and subcellular localization of the fusion protein. | the rola gene is transferred naturally by agrobacterium rhizogenes to the genome of host plants, where it induces dramatic changes in development of transformed plants, including dwarfism and leaf wrinkling. the predicted translation product of the rola gene is a small (11.4 kda), basic (pi = 11.2) protein, which has no clearly significant similarity to sequences in the data bases. we have introduced into the tobacco genome a gene encoding a rola::gus fusion protein. expression of this gene led ... | 1998 | 9725017 |
| protein phosphorylation during coconut zygotic embryo development | evidence was obtained on the occurrence of protein threonine, serine, and tyrosine (tyr) kinases in developing coconut (cocos nucifera l. ) zygotic embryos, based on in vitro phosphorylation of proteins in the presence of [gamma-32p]atp, alkaline treatment, and thin-layer chromatography analysis, which showed the presence of [32p]phosphoserine, [32p]phosphothreonine, and [32p]phosphotyrosine in [32p]-labeled protein hydrolyzates. tyr kinase activity was further confirmed in extracts of embryos a ... | 1998 | 9733545 |
| a new class of caulobacter crescentus flagellar genes. | eight caulobacter crescentus flagellar genes, flma, flmb, flmc, flmd, flme, flmf, flmg, and flmh, have been cloned and characterized. these eight genes are clustered in pairs (flmab, flmcd, flmef, and flmgh) that appear to be structurally organized as operons. homology comparisons suggest that the proteins encoded by the flm genes may be involved in posttranslational modification of flagellins or proteins that interact with flagellin monomers prior to their assembly into a flagellar filament. ex ... | 1998 | 9748431 |
| gain of function assays identify non-rol genes from agrobacterium rhizogenes tl-dna that alter plant morphogenesis or hormone sensitivity. | this study tested the morphogenetic potential of 15 open reading frames of the tl-dna of agrobacterium rhizogenes strain hri. these open reading frames were expressed individually under the control of the 35s rna promoter in transgenic tobacco plants (nicotiana tabacum l.). expression of three t-dna loci, orf3n, orf8 and orf13, alters plant morphogenesis or the response of transgenic tissues to plant hormones. orf3n transgenic plants are characterized by retarded flowering, altered internode elo ... | 1998 | 9750353 |
| construction of a range of derivatives of the biological control strain agrobacterium rhizogenes k84: a study of factors involved in biological control of crown gall disease | the biological control strain agrobacterium rhizogenes k84 is an effective agent in the control of agrobacterium pathogens, the causative agents of crown gall disease. a number of factors are thought to play a role in the control process, including production of the specific agrocins 84 and 434, which differ in the spectra of pathogenic strains that they inhibit in vitro. a range of derivatives of strain k84 has been developed with every combination of the three resident plasmids, pagk84, pagk43 ... | 1998 | 9758829 |
| molecular diversity of rhizobia occurring on native shrubby legumes in southeastern australia | the structure of rhizobial communities nodulating native shrubby legumes in open eucalypt forest of southeastern australia was investigated by a molecular approach. twenty-one genomic species were characterized by small-subunit ribosomal dna pcr-restriction fragment length polymorphism and phylogenetic analyses, among 745 rhizobial strains isolated from nodules sampled on 32 different legume host species at 12 sites. among these rhizobial genomic species, 16 belonged to the bradyrhizobium subgro ... | 1998 | 9758831 |
| natural genetic transformation by agrobacterium rhizogenes . annual flowering in two biennials, belgian endive and carrot | genetic transformation of belgian endive (cichorium intybus) and carrot (daucus carota) by agrobacterium rhizogenes resulted in a transformed phenotype, including annual flowering. back-crossing of transformed (r1) endive plants produced a line that retained annual flowering in the absence of the other traits associated with a. rhizogenes transformation. annualism was correlated with the segregation of a truncated transferred dna (t-dna) insertion. during vegetative growth, carbohydrate reserves ... | 1998 | 9765539 |
| the phenolic recognition profiles of the agrobacterium tumefaciens vira protein are broadened by a high level of the sugar binding protein chve. | the formation of crown gall tumors by agrobacterium tumefaciens requires that the virulence (vir) genes be induced by chemical signals which consist of specific phenolic compounds and monosaccharides, synthesized at plant wound sites. signal transduction in the activation of these genes is mediated by the vira-virg two-component regulatory system, together with chve, a glucose-galactose binding protein which interacts with vira. we have previously presented genetic evidence that vira senses phen ... | 1998 | 9791112 |
| a tobacco homologue of the ri-plasmid orf13 gene causes cell proliferation in carrot root discs. | the tobacco genome contains genes, called cellular rol (c-rol) genes, that are very similar in sequence to genes present in the t-dna of the agrobacterium rhizogenes ri-plasmid. we have cloned two homologues (torf13-1 and torf13-2) of the ri-plasmid orf13 gene from nicotiana tabacum l. cv. havana 425. the clone torf13-1 has a 594-bp open reading frame (orf) which is similar in sequence (77-82% for dna and 67-77% for the deduced amino acid sequence) to orf13 genes of the agropine, mikimopine, and ... | 1998 | 9819048 |
| insertion of microscopic objects through plant cell walls using laser microsurgery | a detailed protocol is presented for precisely inserting microscopic objects into the periplasmic region of plant callus cells using laser microsurgery. ginkgo biloba and agrobacterium rhizogenes were used as the model system for developing the optical tweezers and scalpel techniques using a single laser. we achieved better than 95% survival after plasmolyzing g. biloba cells, ablating a 2-4-μm hole through the cell wall using a pulsed uv laser beam, trapping and translating bacteria into the pe ... | 1998 | 10099438 |
| evidence of protein-tyrosine kinase activity in catharanthus roseus roots transformed by agrobacterium rhizogenes. | homogenate fractions (soluble and particulate) from transformed roots of catharanthus roseus (l.) g. don showed several phosphorylated proteins when incubated with gamma-[32p]atp. the phosphorylation in the proteins of 55, 40, 25, 18 and 10 kda in the particulate fraction and 63 kda in the soluble fraction was resistant to alkali treatment. several proteins in both fractions gave a positive signal with monoclonal antiphosphotyrosine antibodies. in-situ phosphorylation in both fractions showed se ... | 1998 | 9443385 |
| host cell killing and bacterial conjugation require overlapping sets of genes within a 22-kb region of the legionella pneumophila genome. | a 22-kb dna locus of legionella pneumophila is described that contains 18 genes, 16 of which are required for macrophage killing (icm genes). in this paper two previously described icm loci were linked by the discovery of five genes located between the two loci. four of the newly described genes are required for macrophage killing (icmmlke) and one is dispensable. the 16 icm genes appeared to be organized as six individual genes (icmr, icmq, icmg, icmc, icmd, and icmf), and four operons (icmts, ... | 1998 | 9465074 |