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characterization of plasmid-borne and chromosome-encoded traits of agrobacterium biovar 1, 2, and 3 strains from france.we collected 111 agrobacterium isolates from galls of various origins (most of them from france) and analyzed both their plasmid-borne and chromosome-encoded traits. phenotypic analysis of these strains allowed their classification in three phena which exactly matched the delineation of biovars 1, 2, and 3. a fourth phenon was identified which comprises three atypical strains. the phenotypic analysis has also allowed us to identify 12 additional characteristics which could be used to identify th ...200010788345
agrobacterium rhizogenes-transformed roots of medicago truncatula for the study of nitrogen-fixing and endomycorrhizal symbiotic associations.medicago truncatula, a diploid autogamous legume, is currently being developed as a model plant for the study of root endosymbiotic associations, including nodulation and mycorrhizal colonization. an important requirement for such a plant is the possibility of rapidly introducing and analyzing chimeric gene constructs in root tissues. for this reason, we developed and optimized a convenient protocol for agrobacterium rhizogenes-mediated transformation of m. truncatula. this unusual protocol, whi ...200111386364
cambial-region-specific expression of the agrobacterium iaa genes in transgenic aspen visualized by a linked uida reporter gene.the level of indole-3-acetic acid (iaa) was locally modified in cambial tissues of transgenic aspen (populus tremula l. x populus tremuloides michx.). we also demonstrate the use of a linked reporter gene to visualize the expression of the iaa genes. the rate-limiting bacterial iaa-biosynthetic gene iaam and the reporter gene for beta-glucuronidase (gus), uida, were each fused to the cambial-region-specific agrobacterium rhizogenes rolc promoter and linked on the same t-dna. in situ hybridizatio ...200010859183
cpp1, a dna-binding protein involved in the expression of a soybean leghemoglobin c3 gene.nodulin genes are specifically expressed in the nitrogen-fixing root nodules. we have identified a novel type of dna-binding protein (cpp1) interacting with the promoter of the soybean leghemoglobin gene gmlbc3. the dna-binding domain of cpp1 contains two similar cys-rich domains with 9 and 10 cys, respectively. genes encoding similar domains have been identified in arabidopsis thaliana, caenorhabditis elegans, the mouse, and human. the domains also have some homology to a cys-rich region presen ...200010859345
efficient vir gene induction in agrobacterium tumefaciens requires vira, virg, and vir box from the same ti plasmid.the vir genes of octopine, nopaline, and l,l-succinamopine ti plasmids exhibit structural and functional similarities. however, we observed differences in the interactions between octopine and nopaline vir components. the induction of an octopine vire(a6)::lacz fusion (psm358cd) was 2.3-fold higher in an octopine strain (a348) than in a nopaline strain (c58). supplementation of the octopine virg(a6) in a nopaline strain with psm358 did not completely restore vire(a6) induction. however, addition ...200111395473
the bases of crown gall tumorigenesis. 200010869063
colonization of arbuscular-mycorrhizal fungi on ri t-dna transformed roots in synthetic medium.hairy root culture of tomato (lycopersicon esculantum l.) was induced with three strains of agrobacterium rhizogenes namely a4, atcc 15834 and lba 9402. the best response in terms of growth of hairy root was observed with a. rhizogenes strain a4 and lba 9402 followed by atcc 15834. hairy roots were maintained on murashige and skoog (ms) medium but it could also grow on minimal (m) medium. spores of gigaspora margarita were isolated by wet sieving and decanting method and further recovered by suc ...200011395961
nodule-expressed cyp15a cysteine protease genes map to syntenic genome regions in pisum and medicago spp.pscyp15a is a gene that encodes a vacuolar cysteine protease expressed in wilt-induced shoots of pisum sativum (pea) and in root nodules. to further the understanding of nodular pscyp15a expression, a region 5' to the coding sequence of the gene was cloned. varying lengths of 5' untranslated sequence were fused with the uida coding region and introduced from agrobacterium rhizogenes into "hairy roots" of vicia hirsuta. in this transgenic root nodulation assay, a promoter sequence of 900 bp was s ...200010875332
the orf8 gene product of agrobacterium rhizogenes tl-dna has tryptophan 2-monooxygenase activity.the open reading frame 8 (orf8) is located on the tl-dna of the phytopathogenic soil bacterium agrobacterium rhizogenes strain a4. the predicted orf8 protein has a particular structure and is possibly a natural fusion protein. the n-terminal domain shows homology to the a. rhizogenes rolb protein and may modulate the auxin responsiveness of host cells. the c terminus has up to 38% homology to tryptophan 2-monooxygenases (t2m). we show that orf8 overexpressing plants contain a fivefold higher con ...200010875340
increasing tryptophan synthesis in a forage legume astragalus sinicus by expressing the tobacco feedback-insensitive anthranilate synthase (asa2) gene.a cdna clone that encodes a feedback-insensitive anthranilate synthase (as), asa2, isolated from a 5-methyl-tryptophan (trp) (5mt)-resistant tobacco cell line under the control of the constitutive cauliflower mosaic virus 35s promoter, was introduced into the forage legume astragalus sinicus by agrobacterium rhizogenes with kanamycin selection. the 35s-asa2 gene was expressed constitutively as demonstrated by northern-blot hybridization analyses and the presence of feedback-insensitive as. hairy ...200010889256
a study of the production of essential oils in chamomile hairy root cultures.the active substances in chamomile (matricaria recutita l.) belong to chemically different structural types. the largest group of medically important compounds forming the essential oils are primarily chamazulene, (-)-alpha-bisabolol, bisabololoxides, bisabolonoxide a, trans-beta-farnesene, alpha-farnesene, spathulenol and the cis/trans-en-in-dicycloethers. flavonoids, coumarins, mucilages, mono- and oligosaccharides also have pharmacological effects. we studied the production of essential oils ...199910892892
analysis of unique variable region of a plant root inducing plasmid, pri1724, by the construction of its physical map and library.ri plasmids in agrobacterium rhizogenes specifically induce the hairy root syndrome on various dicotyledonous plants. its t-dna transfer system as well as those of ti plasmids have successfully provided the fundamental technique to introduce exogenous genes into plants. to study the ri genome structure, we constructed a complete bamhi physical map and a lambda library of pri1724 of a. rhizogenes strain 1724. by using these, we carried out the complete sequence of the 74-kb region between the rig ...200010907845
the regulation of solasodine production by agrobacterium rhizogenes-transformed roots of solanum aviculare.transgenic roots of solanum spp. containing extra copies of an hmgr gene derived from artemisia annua have been obtained via transformation with agrobacterium rhizogenes. hairy root clones of solanum aviculare which were transgenic for hmgr typically grew faster than those which did not contain extra copies of this gene and also accumulated up to 4.2 times more solasodine when grown under dark, but not light, conditions. the implications of these findings with respect to the regulation of solaso ...200010909266
increased ability of transgenic plants expressing the bacterial enzyme acc deaminase to accumulate cd, co, cu, ni, pb, and zn.transgenic tomato plants lycopersicon esculentum (solanaceae) cv. heinz 902 expressing the bacterial gene 1-aminocyclopropane-1-carboxylic acid (acc) deaminase, under the transcriptional control of either two tandem 35s cauliflower mosaic virus promoters (constitutive expression), the rold promoter from agrobacterium rhizogenes (root specific expression) or the pathogenesis related prb-1b promoter from tobacco, were compared to non-transgenic tomato plants in their ability to grow in the presenc ...200010936659
simultaneous determination of scopolamine, hyoscyamine and littorine in plants and different hairy root clones of hyoscyamus muticus by micellar electrokinetic chromatography.hyoscyamus muticus hairy root clones were established following infection with agrobacterium rhizogenes strains a4, lba-9402 and 15834 and with a. tumefaciens strain c58c1prtgus104. the accumulation of tropane alkaloids hyoscyamine, littorine and scopolamine was evaluated by micellar electrokinetic capillary electrophoresis. littorine was reported for the first time in these clones as well as in the roots of the intact plant and confirmed by collision induced dissociation-mass spectrometry. trop ...200010939356
agrobacterium rhizogenes-mediated transformation of opium poppy, papaver somniferum l., and california poppy, eschscholzia californica cham., root cultures.an efficient protocol for the establishment of transgenic opium poppy (papaver somniferum l.) and california poppy (eschscholzia californica cham.) root cultures using a. grobacterium rhizogenes is reported. five strains of a. rhizogenes were tested for their ability to produce hairy roots on wounded opium poppy seedlings and california poppy embryogenic calli. three of the strains induced hairy root formation on both species, whereas two others either caused the growth of tumorigenic calli or p ...200010948228
characterisation of phaseolus symbionts isolated from mediterranean soils and analysis of genetic factors related to ph tolerance.the ultimate objective of phimed, in which two european (germany, italy) and two mediterranean (morocco, egypt) countries collaborate, is to improve the cultivation of french bean (phaseolus vulgaris) under arid and semi-arid conditions by analysing and enhancing stress tolerance of the nitrogen fixing rhizobial microsymbionts. rhizobial strains nodulating p. vulgaris (rp strains) isolated from areas in morocco frequently subjected to drought were analysed for their salt and ph tolerance and the ...200111566393
flavonoids from glycyrrhiza pallidiflora hairy root cultures.glycyrrhiza pallidiflora hairy roots were induced from axenic young plants by direct infection with agrobacterium rhizogenes. the chemical constituents were then investigated after mass culture. the isoflavone, licoagroisoflavone and the coumestan, licoagroside c, were isolated along with seven known flavonoids. their structures were determined on the basis of spectroscopic evidence.200111576605
identification of the partitioning site within the repabc-type replicon of the composite paracoccus versutus plasmid ptav1.the replicator region of composite plasmid ptav1 of paracoccus versutus (included in mini-replicon ptav320) belongs to the family of repabc replicons commonly found in plasmids harbored by agrobacterium and rhizobium spp. the repabc replicons encode three genes clustered in an operon, which are involved in partitioning (repa and repb) and replication (repc). in order to localize the partitioning site of ptav320, the two identified incompatibility determinants of this mini-replicon (inc1, located ...200111591666
orit-directed cloning of defined large regions from bacterial genomes: identification of the sinorhizobium meliloti pexo megaplasmid replicator region.we have developed a procedure to directly clone large fragments from the genome of the soil bacterium sinorhizobium meliloti. specific regions to be cloned are first flanked by parallel copies of an origin of transfer (orit) together with a plasmid replication origin capable of replicating large clones in escherichia coli but not in the target organism. supplying transfer genes in trans specifically transfers the orit-flanked region, and in this process, site-specific recombination at the orit s ...200010986253
tropane alkaloid production by hairy roots of atropa belladonna obtained after transformation with agrobacterium rhizogenes 15834 and agrobacterium tumefaciens containing rol a, b, c genes only.atropa belladonna leaf disks were infected by a wild strain agrobacterium rhizogenes 15834 harboring the ri-tl-dna and by a disarmed agrobacterium tumefaciens strain harboring a construction with only rol abc and npt ii genes. thirteen root lines were established and examined for their growth rate and alkaloid productivity to evaluate the possible role of rol genes in morphological differentiation and in tropane alkaloid formation. a great diversity has been observed in the growth rate of these ...200010989174
medicinal plant biotechnology: the apiaceae family as the example of rapid development.this article reviews the results of research representative of different trends in biotechnological studies of the apiaceae species. these species are a well-known source of many important herbal products. a number of investigations focus on the biosynthesis of secondary metabolites in plant in vitro cultures. there are also numerous reports concerning the methods of plant micropropagation, especially using somatic embryogenesis. the papers dealing with the usage of the enzymatic potential of pl ...200010989831
genetic engineering on shikonin biosynthesis: expression of the bacterial ubia gene in lithospermum erythrorhizon.the naphthoquinone pigment shikonin from lithospermum erythrorhizon sieb. et zucc. (boraginaceae) was the first plant secondary metabolite produced in industrial scale from plant cell cultures. we have now manipulated the biosynthetic pathway leading to shikonin in l. erythrorhizon by introduction of the bacterial gene ubia. this gene of escherichia coli encodes 4-hydroxybenzoate-3-polyprenyltransferase, a membrane-bound enzyme that catalyzes a key step in ubiquinone biosynthesis. using geranyl ...200011038051
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 ...199811711074
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.199811711110
root hairiness: effect on fluid flow and oxygen transfer in hairy root cultures.the effect of root hairiness on fluid flow and oxygen transfer in hairy root cultures was investigated using wild-type, transgenic and root-hair mutants of arabidopsis thaliana. the root hair morphologies of the a. thaliana lines were hairless, short hairs, moderately hairy (wild-type) and excessively hairy, and these morphologies were maintained after transformation of seedlings with agrobacterium rhizogenes. filtration experiments were used to determine the permeability of packed beds of roots ...200011051417
the effect of yeast elicitor on the growth and secondary metabolism of hairy root cultures of salvia miltiorrhiza.hairy root cultures of salvia miltiorrhiza transformed with agrobacterium rhizogenes atcc 15834 produced a tiny amount of tanshinones and a constituent level of phenolic acids under normal growth conditions. upon elicitation with yeast elicitor, the production of both phenolic acids and tanshinones was enhanced. for example, the contents of two phenolic acids, rosmarinic acid and lithospermic acid b were elevated from 1.24% and 2.59% to 2.89% and 2.98% of dry wt, respectively while the intracell ...200111118603
establishment of hairy root cultures of ammi majus.axenically grown ammi majus plantlets were inoculated with seven different agrobacterium rhizogenes strains. hairy root lines were established only after inoculation with the two agropine strains: a4 and lba9402. the growth rate of hairy root cultures was about thirty times faster than that of callus and cell suspension cultures. polymerase chain reaction with primers for the genes rolb and rolc confirmed the integration of the t-dna fragment of ri plasmid of a. rhizogenes to the genome of hairy ...200111164597
cloning, sequencing, and expression of the cold-inducible hutu gene from the antarctic psychrotrophic bacterium pseudomonas syringae.a promoter-fusion study with a tn 5-based promoter probe vector had earlier found that the hutu gene which encodes the enzyme urocanase for the histidine utilization pathway is upregulated at a lower temperature (4 degrees c) in the antarctic psychrotrophic bacterium pseudomonas syringae. to examine the characteristics of the urocanase gene and its promoter elements from the psychrotroph, the complete hutu and its upstream region from p. syringae were cloned, sequenced, and analyzed in the prese ...200211772602
polyprenols in hairy roots of coluria geoides.long-chain polyisoprenoid alcohols built from several up to more than 100 isoprenoid units are common constituents of all living organisms. they were found mostly in plants, bacteria, yeasts and mammalian cells. in vitro hairy root culture of coluria geoides was obtained from plants transformed with agrobacterium rhizogenes. growth was optimal at 0.75% (w/v) glucose and at 22 degrees c. dry samples of roots were extracted and lipid content was analysed by hplc. according to our estimation, polyp ...200011171209
a revision of rhizobium frank 1889, with an emended description of the genus, and the inclusion of all species of agrobacterium conn 1942 and allorhizobium undicola de lajudie et al. 1998 as new combinations: rhizobium radiobacter, r. rhizogenes, r. rubi, r. undicola and r. vitis.rhizobium, agrobacterium and allorhizobium are genera within the bacterial family rhizobiaceae, together with sinorhizobium. the species of agrobacterium, agrobacterium tumefaciens (syn. agrobacterium radiobacter), agrobacterium rhizogenes, agrobacterium rubi and agrobacterium vitis, together with allorhizobium undicola, form a monophyletic group with all rhizobium species, based on comparative 16s rdna analyses. agrobacterium is an artificial genus comprising plant-pathogenic species. the monop ...200111211278
mikimopine synthase (mis) gene on pri1724.by determination of the nucleotide sequence adjacent to the right border of t-dna of the mikimopine-type ri plasmid (pri1724) in agrobacterium rhizogenes, a new open reading frame (orf) encoding 318 amino acids was found. a transcript of 1.35 kb derived from this orf was observed in hairy roots of ajuga reptans by northern blotting analysis. including its own promoter and terminator, this orf was isolated from the pri1724 t-dna and introduced into tobacco plants by the agrobacterium-binary vecto ...200111223242
biological activity of the rolb-like 5' end of the a4-orf8 gene from the agrobacterium rhizogenes tl-dna.the iaam gene from different plant-associated bacteria encodes a tryptophan monooxygenase (iaam) that catalyzes the synthesis of indole-3-acetamide (iam), a precursor of indole-3-acetic acid (iaa). unlike the iaam proteins from other bacteria, agrobacterium spp. t-dna-encoded iaam proteins carry a 200 amino acid n-terminal extension with low homology to various members of the rolb protein family. this family is composed of 18 highly divergent t-dna-encoded proteins, the basic functions of which ...200111277438
decreased scopolamine yield in field-grown duboisia plants regenerated from hairy roots.hairy root cultures were obtained from hybrid clones of duboisia myoporoides x d. leichhardtii following transformation by agrobacterium rhizogenes strain a4. shoots spontaneously regenerating from the hairy root cultures were rooted and transferred to soil. the plants displayed typical morphological alterations known as hairy root syndrome to varying degrees. pcr analysis confirmed that all transformed plants contained the rola, rolb and rolc genes, irrespective of the degree of morphological a ...200111345697
ginsenoside production in different phenotypes of panax ginseng transformed roots.transformed roots were obtained after the inoculation of sterile root discs of panax ginseng c.a. meyer with agrobacterium rhizogenes a4. the established hairy root lines displayed three morphological phenotypes when cultured on hormone-free liquid schenk and hildebrandt medium. most of the cultures showed the characteristic traits of hairy roots (hr-m), while others were either callus-like (c-m) or thin (t-m) without branching. the growth rate of the transformed root lines was always higher tha ...200111393515
expression of a crown gall biological control phenotype in an avirulent strain of agrobacterium vitis by addition of the trifolitoxin production and resistance genes.agrobacterium vitis is a causal agent of crown-gall disease. trifolitoxin (tfx) is a peptide antibiotic active only against members of a specific group of alpha-proteobacteria that includes agrobacterium and its close relatives. the ability of tfx production by an avirulent strain of agrobacterium to reduce crown gall disease is examined here.200211882255
global versus local regulatory roles for lrp-related proteins: haemophilus influenzae as a case study.lrp (leucine-responsive regulatory protein) plays a global regulatory role in escherichia coli, affecting expression of dozens of operons. numerous lrp-related genes have been identified in different bacteria and archaea, including asnc, an e. coli gene that was the first reported member of this family. pairwise comparisons of amino acid sequences of the corresponding proteins shows an average sequence identity of only 29% for the vast majority of comparisons. by contrast, lrp-related proteins f ...200111395465
polyamines and plant alkaloids.naturally occurring alkaloids are nitrogenous compounds that constitute the pharmacogenically active basic principles of flowering plants. alkaloids are classified into several biogenically related groups. tobacco alkaloids are metabolised from polyamines and diamines putrescine and cadaverine. n-methyl transferase is the first enzyme in alkaloid biosynthetic pathway which drives the flow of nitrogen away from polyamine biosynthesis to alkaloid biosynthesis. arginine decarboxylase has been sugge ...200011395950
nodule-specific regulation of phosphatidylinositol transfer protein expression in lotus japonicus.phosphatidylinositol transfer proteins (pitps) modulate signal transduction pathways and membrane-trafficking functions in eukaryotes. here, we describe the characterization of a gene family from lotus japonicus that encodes a novel class of plant pitp-like proteins (ljplps) and that is regulated in an unusual nodule-specific manner. members of this gene family were identified based on their nucleotide sequence homology with a previously described cdna, ljnod16, which encodes the l. japonicus la ...200111402166
structural and functional characterization of is679 and is66-family elements.a new insertion sequence (is) element, is679 (2,704 bp in length), has been identified in plasmid pb171 of enteropathogenic escherichia coli b171. is679 has imperfect 25-bp terminal inverted repeats (irs) and three open reading frames (orfs) (here called tnpa, tnpb, and tnpc). a plasmid carrying a composite transposon (tn679) with the kanamycin resistance gene flanked by an intact is679 sequence and an is679 fragment with only irr (ir on the right) was constructed to clarify the transposition ac ...200111418571
transformation of catalpa ovata by agrobacterium rhizogenes and phenylethanoid glycosides production in transformed root cultures.transformed root cultures of catalpa ovata were established following shoots infection with four agropine strains of agrobacterium rhizogenes. frequency of root formation was dependent on the bacterial strain and the presence of acetosyringone in the incubation medium. it is the first report concerning the possibility of transforming catalpa ovata by a. rhizogenes. both transformed and untransformed root cultures of c. ovata were studied for their growth and phenylethanoid glycoside production. ...200111421453
ocatin. a novel tuber storage protein from the andean tuber crop oca with antibacterial and antifungal activities.the most abundant soluble tuber protein from the andean crop oca (oxalis tuberosa mol.), named ocatin, has been purified and characterized. ocatin accounts for 40% to 60% of the total soluble oca tuber proteins, has an apparent molecular mass of 18 kd and an isoelectric point of 4.8. this protein appears to be found only in tubers and is accumulated only within the cells of the pith and peridermis layers (peel) of the tuber as it develops. ocatin inhibits the growth of several phytopathogenic ba ...200211950978
the horizontal transfer of agrobacterium rhizogenes genes and the evolution of the genus nicotiana.with the aim of understanding better the distribution and evolution of agrobacterium rhizogenes genes transferred in the genus nicotiana, 42 species were screened for presence of rolb, rolc, orf13, and orf14. the transferred sequences were then compared within the genus and with current bacterial sequences. the results obtained showed the presence of at least one bacterial gene in 15 species belonging to different subgenera. sequence analyses supported the hypothesis of coevolution of bacterial ...200111421651
specific detection of bradyrhizobium and rhizobium strains colonizing rice (oryza sativa) roots by 16s-23s ribosomal dna intergenic spacer-targeted pcr.in addition to forming symbiotic nodules on legumes, rhizobial strains are members of soil or rhizosphere communities or occur as endophytes, e.g., in rice. two rhizobial strains which have been isolated from root nodules of the aquatic legumes aeschynomene fluminensis (irbg271) and sesbania aculeata (irbg74) were previously found to promote rice growth. in addition to analyzing their phylogenetic positions, we assessed the suitability of the 16s-23s ribosomal dna (rdna) intergenic spacer (igs) ...200111472944
4-hydroxycinnamoyl-coa hydratase/lyase, an enzyme of phenylpropanoid cleavage from pseudomonas, causes formation of c(6)-c(1) acid and alcohol glucose conjugates when expressed in hairy roots of datura stramonium l.4-hydroxycinnamoyl-coa hydratase/lyase (hchl), a crotonase homologue of phenylpropanoid catabolism from pseudomonas fluorescens strain an103, led to the formation of 4-hydroxybenzaldehyde metabolites when expressed in hairy root cultures of datura stramonium l. established by transformation with agrobacterium rhizogenes. the principal new compounds observed were the glucoside and glucose ester of 4-hydroxybenzoic acid, together with 4-hydroxybenzyl alcohol- o-beta- d-glucoside. in lines actively ...200212012244
antimicrobial properties of pyridine-2,6-dithiocarboxylic acid, a metal chelator produced by pseudomonas spp.pyridine-2,6-dithiocarboxylic acid (pdtc) is a metal chelator produced by pseudomonas spp. it has been shown to be involved in the biodegradation of carbon tetrachloride; however, little is known about its biological function. in this study, we examined the antimicrobial properties of pdtc and the mechanism of its antibiotic activity. the growth of pseudomonas stutzeri strain kc, a pdtc-producing strain, was significantly enhanced by 32 microm pdtc. all nonpseudomonads and two strains of p. stut ...200111525988
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 ...199611540728
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 ...199711541870
targeting a nuclear anthranilate synthase alpha-subunit gene to the tobacco plastid genome results in enhanced tryptophan biosynthesis. return of a gene to its pre-endosymbiotic origin.anthranilate synthase (as), the control enzyme of the tryptophan (trp) biosynthetic pathway, is encoded by nuclear genes, but is transported into the plastids. a tobacco (nicotiana tabacum) cdna (asa2) encoding a feedback-insensitive tobacco as alpha-subunit was transformed into two different sites of the tobacco plastid genome through site-specific insertion to obtain transplastomic plants with normal phenotype and fertility. a high and uniform level of asa2 mrna was observed in the transplasto ...200111553741
characterization of a brucella species 25-kilobase dna fragment deleted from brucella abortus reveals a large gene cluster related to the synthesis of a polysaccharide.in the present study we completed the nucleotide sequence of a brucella melitensis 16m dna fragment deleted from b. abortus that accounts for 25,064 bp and show that the other brucella spp. contain the entire 25-kb dna fragment. two short direct repeats of four nucleotides, detected in the b. melitensis 16m dna flanking both sides of the fragment deleted from b. abortus, might have been involved in the deletion formation by a strand slippage mechanism during replication. in addition to omp31, co ...200111598046
plant-dependent genotypic and phenotypic diversity of antagonistic rhizobacteria isolated from different verticillium host plants.to study the effect of plant species on the abundance and diversity of bacterial antagonists, the abundance, the phenotypic diversity, and the genotypic diversity of rhizobacteria isolated from potato, oilseed rape, and strawberry and from bulk soil which showed antagonistic activity towards the soilborne pathogen verticillium dahliae kleb. were analyzed. rhizosphere and soil samples were taken five times over two growing seasons in 1998 and 1999 from a randomized field trial. bacterial isolates ...200212089011
the plant oncogene rold encodes a functional ornithine cyclodeaminase.the plant oncogene rold stimulates the reproductive phase transition in plants. we define here the function of its gene product. we show that the rold protein bears sequence homology with ornithine cyclodeaminase, an uncommon enzyme of specialized-niche eubacteria and archaea that catalyzes the unusual nad(+)-dependent conversion of ornithine to proline. to confirm the prediction of the bioinformatic analysis, the rold protein was expressed in escherichia coli and purified. an ornithine-dependen ...200111687622
rnai-mediated oncogene silencing confers resistance to crown gall tumorigenesis.crown gall disease, caused by the soil bacterium agrobacterium tumefaciens, results in significant economic losses in perennial crops worldwide. a. tumefaciens is one of the few organisms with a well characterized horizontal gene transfer system, possessing a suite of oncogenes that, when integrated into the plant genome, orchestrate de novo auxin and cytokinin biosynthesis to generate tumors. specifically, the iaam and ipt oncogenes, which show approximately 90% dna sequence identity across stu ...200111687652
strain-specific genes of helicobacter pylori: distribution, function and dynamics.whole-genome clustering of the two available genome sequences of helicobacter pylori strains 26695 and j99 allows the detection of 110 and 52 strain-specific genes, respectively. this set of strain-specific genes was compared with the sets obtained with other computational approaches of direct genome comparison as well as experimental data from microarray analysis. a considerable number of novel function assignments is possible using database-driven sequence annotation, although the function of ...200111691927
site-specific integrative elements of rhizobiophage 16-3 can integrate into proline trna (cgg) genes in different bacterial genera.the integrase protein of the rhizobium meliloti 41 phage 16-3 has been classified as a member of the int family of tyrosine recombinases. the site-specific recombination system of the phage belongs to the group in which the target site of integration (attb) is within a trna gene. since trna genes are conserved, we expected that the target sequence of the site-specific recombination system of the 16-3 phage could occur in other species and integration could take place if the required putative hos ...200211741858
sotolone production by hairy root cultures of trigonella foenum-graecum in airlift with mesh bioreactors.3-hydroxy-4,5-dimethyl-2(5h)-furanone (sotolone) and 3-amino-4,5-dimethyl-2(5h)-furanone, the postulated precursor of sotolone, were detected in hairy root cultures of trigonella foenum-graecum (fenugreek) by gc-ms. the hairy root cultures in both conical flasks and airlift with mesh bioreactors were achieved from hypocotyl of seedling by infection with agrobacterium rhizogenes. in flasks, the mathematical relationship between hairy root growth and conductivity was established and afterward used ...200111743801
phylogenies of atpd and reca support the small subunit rrna-based classification of rhizobia.the current classification of the rhizobia (root-nodule symbionts) assigns them to six genera. it is strongly influenced by the small subunit (16s, ssu) rrna molecular phylogeny, but such single-gene phylogenies may not reflect the evolution of the genome as a whole. to test this, parts of the atpd and reca genes have been sequenced for 25 type strains within the alpha-proteobacteria, representing species in rhizobium, sinorhizobium, mesorhizobium, bradyrhizobium, azorhizobium, agrobacterium, ph ...200111760945
expression of functional mammalian p450 2e1 in hairy root cultures.p450 2e1 is an important mammalian liver enzyme known to metabolize a wide range of compounds including several common environmental pollutants. the medicinal plant, atropa belladonna, was transformed with agrobacterium rhizogenes containing a binary vector with rabbit p450 2e1 in either the sense or antisense orientation. the resulting "hairy roots" were isolated and grown in liquid medium. production of p450 2e1 protein was verified in the roots containing the 2e1 gene in the sense orientation ...200211787019
optimisation of transgene action at the post-transcriptional level: high quality parthenocarpic fruits in industrial tomatoes.genetic engineering of parthenocarpy confers to horticultural plants the ability to produce fruits under environmental conditions that curtail fruit productivity and quality. the defh9-iaam transgene, whose predicted action is to confer auxin synthesis specifically in the placenta, ovules and derived tissues, has been shown to confer parthenocarpy to several plant species (tobacco, eggplant, tomato) and varieties.200211818033
enhanced podophyllotoxin production from agrobacterium rhizogenes transformed cultures of podophyllum hexandrum.podophyllotoxin, a potent chemotherapeutic agent is obtained from podophyllum hexandrum royle. embryos of p. hexandrum were transformed using different strains of agrobacterium rhizogenes viz. a4, 15834, k599. transformed nature of the calli was ascertained and the cultures were further maintained as individual clones. hplg analysis of transformed cultures depicted a three-fold increase in podophyllotoxin content in comparison to controls.200111833617
the expression of an extensin-like protein correlates with cellular tip growth in tomato.extensins are abundant proteins presumed to determine physical characteristics of the plant cell wall. we have cloned a cdna encoding leext1 from a tomato (lycopersicon esculentum mill.) root hair cdna library. the deduced sequence of the leext1 polypeptide defined a novel type of extensin-like proteins in tomato. patterns of mrna distribution indicated that expression of the leext1 gene was initiated in the root hair differentiation zone of the tomato rhizodermis. cloning of the corresponding p ...200211891247
isoquinoline alkaloid production by transformed cultures of papaver somniferum.three clones of transformed cultures of opium poppy (papaver somniferum l.) were established by infection with agrobacterium rhizogenes maff 03-01724. maff clone 1 being capable of forming somatic embryos was selected and its growth and isoquinoline alkaloid production was investigated. the illumination, temperature and nutrient medium composition greatly affected growth, cell morphology and alkaloid accumulation. the maff clone 1 cultured in root culture medium in the dark at 22 degrees c accum ...200111915285
tolerance and metabolism of phenol and chloroderivatives by hairy root cultures of daucus carota l.hairy root cultures are shown to be suitable experimental systems to screen higher plants for tolerance to various inorganic and organic pollutants, and for determining the role of the root matrix in the uptake and further metabolism of contaminants. a number of clones were obtained by infection of carrot tissues with agrobacterium rhizogenes and two (the fastest and the slowest growing root clones) were chosen for further experimentation. both clones showed a similar degree of tolerance towards ...200211916048
towards growth of arbuscular mycorrhizal fungi independent of a plant host.when surface-sterilized spores of the arbuscular mycorrhizal fungus (amf) glomus intraradices sy167 were germinated on agar plates in the slightly modified minimum mineral medium described by g. bécard and j. a. fortin (new phytol. 108:211-218, 1988), slime-forming bacteria, identified as paenibacillus validus, frequently grew up. these bacteria were able to support growth of the fungus on the agar plates. in the presence of p. validus, hyphae branched profusely and formed coiled structures. the ...200211916713
a phosphate transporter from medicago truncatula involved in the acquisition of phosphate released by arbuscular mycorrhizal fungi.many plants have the capacity to obtain phosphate via a symbiotic association with arbuscular mycorrhizal (am) fungi. in am associations, the fungi release phosphate from differentiated hyphae called arbuscules, that develop within the cortical cells, and the plant transports the phosphate across a symbiotic membrane, called the periarbuscular membrane, into the cortical cell. in medicago truncatula, a model legume used widely for studies of root symbioses, it is apparent that the phosphate tran ...200212368495
mycorrhizal colonization of transgenic aspen in a field trial.mycorrhizal colonization of genetically modified hybrid aspen (populus tremula x p. tremuloides michx.) was investigated over 15 months in a field experiment. the aspen carried the rolc gene from agrobacterium rhizogenes under control of either the constitutive cauliflower mosaic virus 35s promoter or the light-inducible rbcs promoter. arbuscular mycorrhizas (ams) were rare in all root samples, while fully developed ectomycorrhizas (ems) were found in all samples. no significant differences in t ...200211925050
genes from pseudomonas sp. strain bs involved in the conversion of l-2-amino-delta(2)-thiazolin-4-carbonic acid to l-cysteine.dl-2-amino-delta(2)-thiazolin-4-carbonic acid (dl-atc) is a substrate for cysteine synthesis in some bacteria, and this bioconversion has been utilized for cysteine production in industry. we cloned a dna fragment containing the genes involved in the conversion of l-atc to l-cysteine from pseudomonas sp. strain bs. the introduction of this dna fragment into escherichia coli cells enabled them to convert l-atc to cysteine via n-carbamyl-l-cysteine (l-ncc) as an intermediate. the smallest recombin ...200211976087
expression of the antiapoptotic baculovirus p35 gene in tomato blocks programmed cell death and provides broad-spectrum resistance to disease.the sphinganine analog mycotoxin, aal-toxin, induces a death process in plant and animal cells that shows apoptotic morphology. in nature, the aal-toxin is the primary determinant of the alternaria stem canker disease of tomato, thus linking apoptosis to this disease caused by alternaria alternata f. sp. lycopersici. the product of the baculovirus p35 gene is a specific inhibitor of a class of cysteine proteases termed caspases, and naturally functions in infected insects. transgenic tomato plan ...200212403830
genetic and cytogenetic mapping of dmi1, dmi2, and dmi3 genes of medicago truncatula involved in nod factor transduction, nodulation, and mycorrhization.the dmi1, dmi2, and dmi3 genes of medicago truncatula, which are required for both nodulation and mycorrhization, control early steps of nod factor signal transduction. here, we have used diverse approaches to pave the way for the map-based cloning of these genes. molecular amplification fragment length polymorphism markers linked to the three genes were identified by bulked segregant analysis. integration of these markers into the general genetic map of m. truncatula revealed that dmi1, dmi2, a ...200212423016
[hairy-root culture of polygonium multiflorum thunb. and the production of its active constituents-anthraquinones].transformed hairy roots of polygonium multiflorum thunb. were obtained by the transformation of agrobacterium rhizogenes lba9402. it was clearly demonstrated that t-dna of a. rhizogenes ri plasmid was integrated into the cells of hairy roots by the experiments of pcr and southern hybridization. through the screen of basic medium and the research of growth curve of hairy roots, the optimum inoculum time was selected in 30 days or so in the optimum condition-ms medium. on the condition, the conten ...200211977604
[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 ...199812016951
studies on mass production of transformed panax ginseng hairy roots in bioreactor.the growth properties of panax ginseng hairy roots transformed by agrobacterium rhizogenes were compared between flask and aerated column or stirred bioreactor. in flask cultures, sucrose, initially 30 g/l, was nearly exhausted after 45 d of culture. the ph of the medium dropped from 5.5 to 4.96 after 10 d, but afterward it gradually increased to 6.4. after 45 d, hairy roots grew about 16-folds. the growth rate of hairy roots in air-bubble column or stirred bioreactor cultures was 1.13 (1.11) to ...200212018235
optimum conditions for transformed panax ginseng hairy roots in flask culture.panax ginseng hairy roots were transformed by agrobacterium rhizogenes ktct 2744. they showed an active branching pattern and fast growth in hormone-free medium, and good growth at 23 degrees c, ph 5.8, 1/2 ms medium, and 3% sucrose. sucrose provided the highest growth among seven carbon sources tested. six complex media were also tested. in the combined sugar study, hairy roots grew better on sucrose without glucose or fructose than with glucose or fructose. in the 1/2 ms basal medium, 30 mm in ...200212018236
genetic transformation and hairy root induction in holostemma ada-kodien k. schum--a vulnerable medicinal plant.hairy roots were induced from shoot buds and seedling hypocotyls of holostemma by infection with agropine type agrobacterium rhizogenes strains. type of explant, agrobacterium rhizogenes strain used for infection, co-culture time and photoperiod influenced the transformation frequencies. hairy roots were induced from seedling hypocotyls and shoot bud explants upon infection with agropine type agrobacterium rhizogenes strains. the hairy roots were thin, whitish in colour and showed negatively geo ...200112018522
effect of salicylic acid, methyl jasmonate, ethephon and cantharidin on anthraquinone production by rubia cordifolia callus cultures transformed with the rolb and rolc genes.it has been suggested that the rol genes of agrobacterium rhizogenes could play an essential role in the activation of secondary metabolite production in plant transformed cultures. this study investigated whether the content of anthraquinone phytoalexins was changed in callus cultures of rubia cordifolia transgenic for the 35s-rolb and 35s-rolc genes in comparison with a non-transformed callus culture. the anthraquinone content was shown to be significantly increased in transgenic cultures, thu ...200212084477
oligogalacturonides inhibit the induction of late but not of early auxin-responsive genes in tobacco.oligogalacturonides (ogs) released from the plant cell wall regulate several defense responses, as well as various aspects of plant growth and development. in these latter effects, ogs exhibit auxin-antagonist activity. to shed light on the mechanism by which ogs antagonise auxin, we analysed the ability of these oligosaccharides to inhibit the activity of four auxin-up-regulated promoters [pgm-gh3 of soybean (glycine max l. merr.), pnt114 of tobacco (nicotiana tabacum l.), and prolb and prold o ...200212111233
suppressive subtractive hybridization detects extensive genomic diversity in thermotoga maritima.comparisons between genomes of closely related bacteria often show large variations in gene content, even between strains of the same species. such studies have focused mainly on pathogens; here, we examined thermotoga maritima, a free-living hyperthermophilic bacterium, by using suppressive subtractive hybridization. the genome sequence of t. maritima msb8 is available, and dna from this strain served as a reference to obtain strain-specific sequences from thermotoga sp. strain rq2, a very clos ...200212142418
the diversity of phaseolus-nodulating rhizobial populations is altered by liming of acid soils planted with phaseolus vulgaris l. in brazil.pcr-mediated restriction fragment length polymorphism (rflp) analysis of the 16s-23s rrna internally transcribed spacer (its) region and the 16s rrna gene indicated that the rhizobial populations isolated from common bean (phaseolus vulgaris l.) nodules in the unlimed soil from a series of five lime rates applied 6 years previously to plots of an acidic oxisol had less diversity than those from plots with higher rates of liming. isolates affiliated with rhizobium tropici iib and rhizobium legumi ...200212147504
a new type iv secretion system promotes conjugal transfer in agrobacterium tumefaciens.two dna transfer systems encoded by the tumor-inducing (ti) plasmid have been previously identified in agrobacterium tumefaciens. the virb operon is required for the transfer of transferred dna to the plant host, and the trb system encodes functions required for the conjugal transfer of the ti plasmid between cells of agrobacterium. recent availability of the genome sequence of agrobacterium allowed us to identify a third system that is most similar to the virb type iv secretion system of barton ...200212169609
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 ...199611785535
regeneration of plants from callus tissues of hairy roots induced by agrobacterium rhizogenes on alhagi pseudoalhagi.the legume forage alhagi pseudoalhagi was transformed by the agrobacterium rhizogenes strain a4 using cotyledon and hypocotyl segments as infection materials. regenerated plants were achieved from sterile calli derived from hairy roots, which occurred at or near the infection sites. the regenerated plants from hairy root were characterized by normal leaf morphology and stem growth but a shallow and more extensive root system than normal plants. opine synthesis, pcr and southern blot confirmed th ...200111787773
expression of rolb in apomictic hieracium piloselloides vill. causes ectopic meristems in planta and changes in ovule formation, where apomixis initiates at higher frequency.the effects of the agrobacterium rhizogenes rolb oncogene on apomixis were examined in the facultative apomictic plant hieracium piloselloides because the oncogene has been shown to alter plant growth, morphogenesis and cellular sensitivity to auxin. introduction of rolb under the control of either its own promoter or the camv35s promoter induced ectopic meristem formation from the inflorescence, confirming in planta a meristem-inducing role for this oncogene previously observed only in tissue c ...200111800383
hormonal characterization of transgenic tobacco plants expressing the rolc gene of agrobacterium rhizogenes tl-dna.transgenic tobacco (nicotiana tabacum l. cv wisconsin 38) plants expressing the agrobacterium rhizogenes rolc gene under the control of the cauliflower mosaic virus 35s rna promoter were constructed. these plants displayed several morphological alterations reminiscent of changes in indole-3-acetic acid (iaa), cytokinin, and gibberellin (ga) content. however, investigations showed that neither the iaa pool size nor its rate of turnover were altered significantly in the rolc plants. the biggest di ...199312231827
a diffusible factor from arbuscular mycorrhizal fungi induces symbiosis-specific mtenod11 expression in roots of medicago truncatula.using dual cultures of arbuscular mycorrhizal (am) fungi and medicago truncatula separated by a physical barrier, we demonstrate that hyphae from germinating spores produce a diffusible factor that is perceived by roots in the absence of direct physical contact. this am factor elicits expression of the nod factor-inducible gene mtenod11, visualized using a pmtenod11-gusa reporter. transgene induction occurs primarily in the root cortex, with expression stretching from the zone of root hair emerg ...200312644648
transgenic studies on the involvement of cytokinin and gibberellin in male development.numerous plant hormones interact during plant growth and development. elucidating the role of these various hormones on particular tissue types or developmental stages has been difficult with exogenous applications or constitutive expression studies. therefore, we used tissue-specific promoters expressing ckx1 and gai, genes involved in oxidative cytokinin degradation and gibberellin (ga) signal transduction, respectively, to study the roles of cytokinin and ga in male organ development. accumul ...200312644677
the rolb gene of agrobacterium rhizogenes does not increase the auxin sensitivity of tobacco protoplasts by modifying the intracellular auxin concentration.phenotypical alterations observed in rolb-transformed plants have been proposed to result from a rise in intracellular free auxin due to a rolb-catalyzed hydrolysis of auxin conjugates(j.j. estruch, j. schell, a. spena [1991] embo j 10: 3125-3128).we have investigated this hypothesis in detail using tobacco (nicotiana tabacum) mesophyll protoplasts isolated from plants transformed with the rolb gene under the control of its own promoter (bbgus 6 clone) or the cauliflower mosaic virus 35s promote ...199412232224
metabolic control of anaerobic glycolysis (overexpression of lactate dehydrogenase in transgenic tomato roots supports the davies-roberts hypothesis and points to a critical role for lactate secretion.roots of all plants examined so far have the potential for both ethanol and lactate fermentation. a short burst of lactate fermentation usually occurs when plant tissues are transferred from normoxic to anoxic conditions. according to the davies-roberts hypothesis, the consequent ph drop both initiates ethanol fermentation and blocks further production of lactate by inhibiting lactate dehydrogenase (ldh). however, the role of ldh in this ph control mechanism is still a matter of debate. to pertu ...199412232401
the rolb-like part of the agrobacterium rhizogenes orf8 gene inhibits sucrose export in tobacco.many agrobacterium t-dna genes belong to the highly diverse rolb family. the mode of action of most of these genes is still unknown. rolb-like sequences also are present at the 5' ends of the t-dna-located iaam genes and the iaam homolog orf8, whereas iaam genes from pseudomonas and erwinia spp. lack such sequences. iaam genes encode tryptophan monooxygenases; these enzymes convert tryptophan into indole-3-acetamide, a precursor of indole-3-acetic acid. tobacco plants expressing the rolb-like pa ...200212236602
formation and deposition of amylose in the potato tuber starch granule are affected by the reduction of granule-bound starch synthase gene expression.the synthesis of amylose in amyloplasts is catalyzed by granule-bound starch synthase (gbss). gbss gene expression was inhibited via antisense rna in agrobacterium rhizogenes-transformed potato plants. analysis of starch production and starch granule composition in transgenic tubers revealed that reduction of gbss activity always resulted in a reduction of the production of amylose. field experiments, performed over a 2-year period, showed that stable inhibition of gbss gene expression can be ob ...199412244219
agrobacterium rhizogenes-mediated transformation: root cultures as a source of alkaloids.hairy roots, transformed with agrobacterium rhizogenes, have been found to be suitable for the production of secondary metabolites because of their stable and high productivity in hormone-free culture conditions. a number of plant species including many medicinal plants have been successfully transformed with agrobacterium rhizogenes. transformed root cultures have also been found to be a potential source of high-value pharmaceuticals. in this article the most important alkaloids produced by hai ...200212391546
xanthones and secoiridoids from hairy root cultures of centaurium erythraea and c. pulchellum.shoots of centaurium erythraea and c. pulchellum were inoculated with suspension of agrobacterium rhizogenes cells, strain a4m70gus. five clones of c. erythraea hairy roots (a-e) and three clones of c. pulchellum hairy roots (f-h) were selected according to morphological differences. spontaneous bud initiation occurred in clones c, d, g and h. hairy roots retained the capacity for xanthone biosynthesis, with some variation being observed between individual clones. the concentration of xanthones ...200212391565
analysis of nematode-responsive promoters in sugar beet hairy roots.one of the strategies to make crops resistant to the beet cyst nematode heterodera schachtii is the destruction of the feeding site or syncytium. this can be achieved by local expression of the cytotoxic barnase gene under control of a nematode-inducible plant promoter that is active in the syncytium. expression of barnase outside the feeding site has to be neutralized by its inhibitor barstar driven from a constitutive promoter that is downregulated in the syncytium. several promoters that are ...200112425082
a third transposable element, isppu12, from the toluene-xylene catabolic plasmid pww0 of pseudomonas putida mt-2.a 3,372-bp insertion sequence, isppu12, has been identified on the archetypal toluene-xylene tol catabolic plasmid pww0 from pseudomonas putida mt-2. the insertion sequence element is located on the plasmid between bases 84397 and 87768 in a region which also contains the termini and transposase genes of the catabolic transposons tn4651 and tn4653 (a. greated, l. lambertson, p. a. williams, and c. m. thomas, environ. microbiol., in press). isppu12 has terminal inverted repeats of 24 bp with thre ...200212426346
metabolomics of plant saponins: bioprospecting triterpene glycoside diversity with respect to mammalian cell targets.one of the goals of cancer chemotherapy and prevention is the discovery of compounds that are relatively selective to tumor cells and, therefore, have reduced effects on normal cell growth. in previously published studies, it was shown that certain triterpene saponins (called avicins) from a desert tree, acacia victoriae, are selectively toxic to tumor cells at very low doses (ic(50): 0.2 microg/ml for jurkat cells). to extend this research to human clinical studies, we needed to find a reliable ...200212427275
tobacco plants were transformed by agrobacterium rhizogenes infection during their evolution.we discovered that the origin of ct-dna in the genome of wild-type nicotiana glauca is the t-dna of the mikimopine-type ri plasmid (pri) harbored in agrobacterium rhizogenes. the ct-dna was inserted into the genomic dna of n. glauca from the position corresponding to the right border of mikimopine-type pri. the ct-dna contained two mikimopine synthase gene (mis) homologs, ngmisl and ngmisr, both of which were transcribed at low level in all n. glauca organs. ngmisr protein expressed in escherich ...200212472692
expression of self-complementary hairpin rna under the control of the rolc promoter confers systemic disease resistance to plum pox virus without preventing local infection.homology-dependent selective degradation of rna, or post-transcriptional gene silencing (ptgs), is involved in several biological phenomena, including adaptative defense mechanisms against plant viruses. small interfering rnas mediate the selective degradation of target rna by guiding a multicomponent rnase. expression of self-complementary hairpin rnas within two complementary regions separated by an intron elicits ptgs with high efficiency. plum pox virus (ppv) is the etiological agent of shar ...200312823862
pleiotropic effect of the insertion of the agrobacterium rhizogenes rold gene in tomato ( lycopersicon esculentum mill.).the agrobacterium rhizogenes rold gene, coding for an ornithine cyclodeaminase involved in the biosynthesis of proline from ornithine, has been inserted in lycopersicon esculentum cv tondino with the aim of studying its effects on plant morphological characters including pathogen defense response. the analysis of plants transgenic for rold did not show major morphological modifications. first generation transgenic plants however were found to flower earlier, and showed an increased number of inf ...200312830385
convergent evolution of amadori opine catabolic systems in plasmids of agrobacterium tumefaciens.deoxyfructosyl glutamine (dfg, referred to elsewhere as dfg) is a naturally occurring amadori compound found in rotting fruits and vegetables. dfg also is an opine and is found in tumors induced by chrysopine-type strains of agrobacterium tumefaciens. such strains catabolize this opine via a pathway coded for by their plasmids. nt1, a derivative of the nopaline-type a. tumefaciens strain c58 lacking ptic58, can utilize dfg as the sole carbon source. genes for utilization of dfg were mapped to th ...200312511498
molecular characterization of legionella populations present within slow sand filters used for fungal plant pathogen suppression in horticultural crops.the total bacterial community of an experimental slow sand filter (ssf) was analyzed by denaturing gradient gel electrophoresis (dgge) of partial 16s rrna gene pcr products. one dominant band had sequence homology to legionella species, indicating that these bacteria were a large component of the ssf bacterial community. populations within experimental and commercial ssf units were studied by using legionella-specific pcr primers, and products were studied by dgge and quantitative pcr analyses. ...200312514038
[hairy root induction and in vitro cultivation of pueraria lobata willa. ohwi].to study the hairy root induction and hormone-free in vitro liquid cultivation of pueraria lobata (willd) ohwi.200012516461
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