| martelella mediterranea gen. nov., sp. nov., a novel alpha-proteobacterium isolated from a subterranean saline lake. | a bacterial strain was isolated from the water of lake martel in mallorca (spain). the isolate, designated macl11(t), was halotolerant and strictly aerobic. the cells were non-motile, non-spore-forming, gram-negative short rods. comparative 16s rrna gene sequence analysis revealed that macl11(t) represents a separate line of descent within the order 'rhizobiales' of the class 'alphaproteobacteria'. strain macl11(t) was most closely related to the genera rhizobium (93.3 % sequence similarity to r ... | 2005 | 15774691 |
| inhibitory effect of the agrobacterium rhizogenes rolc gene on rabdosiin and rosmarinic acid production in eritrichium sericeum and lithospermum erythrorhizon transformed cell cultures. | rabdosiin and related caffeic acid metabolites have been proposed as active pharmacological agents demonstrating potent anti-hiv and antiallergic activities. we transformed eritrichium sericeum and lithospermum erythrorhizon seedlings by the rolc gene, which has been recently described as an activator of plant secondary metabolism. surprisingly, the rolc-transformed cell cultures of both plants yielded two- to threefold less levels of rabdosiin and rosmarinic acid (ra) than respective control cu ... | 2005 | 15688226 |
| the t-dna oncogene a4-orf8 from agrobacterium rhizogenes a4 induces abnormal growth in tobacco. | the related orf8 and iaam t-dna genes from agrobacterium are each composed of two distinct parts. the 5' parts (called norf8 or niaam) encode a 200-amino-acid (aa) sequence with homology to various t-dna oncoproteins such as rolb, rolc, and 6b. the 3' parts (corf8 or ciaam) encode a 550-aa sequence with homology to iaam proteins from pseudomonas and pantoea spp. whereas iaam genes encode flavin adenine dinucleotide (fad)-dependent tryptophan 2-monooxygenases that catalyze the synthesis of indole ... | 2005 | 15782634 |
| genetically modified hairy roots of withania somnifera dunal: a potent source of rejuvenating principles. | transgenic hairy roots were induced from withania somnifera dunal, by infecting leaf explants with agrobacterium rhizogenes. polymerase chain reaction for rol a gene and southern blot confirmed the integration of t-dna in the genome. cultures were grown in murashige and skoog solid as well as in liquid medium. the antioxidant activity was assayed in roots grown in solid media and liquid media. hairy roots grown in liquid media found to possess highly significant activity in 1,1-diphenyl-2-pecryl ... | 2005 | 15798373 |
| spatial and temporal distribution of polyamine levels and polyamine anabolism in different organs/tissues of the tobacco plant. correlations with age, cell division/expansion, and differentiation. | polyamine (pa) titers and biosynthesis follow a basipetal decrease along the tobacco (nicotiana tabacum) plant axis, and they also correlate negatively with cell size. on the contrary, the titers of arginine (arg), ornithine (orn), and arginase activity increase with age. the free (soluble)/total-pa ratios gradually increase basipetally, but the soluble conjugated decrease, with spermidine (spd) mainly to determine these changes. the shoot apical meristems are the main site of spd and spermine b ... | 2005 | 15849310 |
| a bipartite signal mediates the transfer of type iv secretion substrates of bartonella henselae into human cells. | bacterial type iv secretion (t4s) systems mediate the transfer of macromolecular substrates into various target cells, e.g., the conjugative transfer of dna into bacteria or the transfer of virulence proteins into eukaryotic host cells. the t4s apparatus virb of the vascular tumor-inducing pathogen bartonella henselae causes subversion of human endothelial cell (hec) function. here we report the identification of multiple protein substrates of virb, which, upon translocation into hec, mediate al ... | 2005 | 15642951 |
| protein domains and architectural innovation in plant-associated proteobacteria. | evolution of new complex biological behaviour tends to arise by novel combinations of existing building blocks. the functional and evolutionary building blocks of the proteome are protein domains, the function of a protein being dependent on its constituent domains. we clustered completely-sequenced proteomes of prokaryotes on the basis of their protein domain content, as defined by pfam (release 16.0). this revealed that, although there was a correlation between phylogeny and domain content, ot ... | 2005 | 15715905 |
| rna interference of soybean isoflavone synthase genes leads to silencing in tissues distal to the transformation site and to enhanced susceptibility to phytophthora sojae. | isoflavones are thought to play diverse roles in plant-microbe interactions and are also potentially important to human nutrition and medicine. isoflavone synthase (ifs) is a key enzyme for the formation of the isoflavones. here, we examined the consequences of rnai silencing of genes for this enzyme in soybean (glycine max). soybean cotyledon tissues were transformed with agrobacterium rhizogenes carrying an rnai silencing construct designed to silence expression of both copies of ifs genes. ap ... | 2005 | 15778457 |
| [induction of hairy roots of pueraria phaseoloides and its culture in liquid and solid medium]. | an efficient transformation system for genetic transformation of medicinal plant, pueraria phaseoloides, which contains puerarin and daidzein with hypothermic, spasmolytic, hypotensive and anti-arrhythmic activities, by using agropine-type agrobacterium rhizogenes atcc 15834 was developed. hairy roots could be obtained directly from the cut edges of petioles of leaf explants of p. phaseoloides or via callus 20 days after inoculation with agrobacterium. the percentage of rooted leaf explants 35 d ... | 2003 | 15969012 |
| [induction and culture of hairy boots in phytolacca esculenta and its saponin production]. | hairy roots appeared in vitro 20 days after inoculation of phytolacca esculenta leaf explants with the strain of agrobacterium rhizogenes r1601. the frequency of leaf explants transformed by r1601 was up to 70%. hairy roots can be incited directly from the veins of explants or via callus. hairy roots induced by r1601 grew rapidly on medium ms without hormone and were 85.6% higher in respiration rate than control roots. transformation was confirmed by opine detection and the amplification of rol ... | 2003 | 15969035 |
| [induction of hairy roots of panax ginseng and studies on suitable culture condition of ginseng hairy roots]. | ginseng is a valuable medicinal plant with ginsenosides as its mian effective components. because ginseng is a perennial plant and has a very strict demand for soil conditions, the way of cultivating ginseng by cutting woods is still used in china at present and thus forest resources has been extremely destroyed. increasing attention has been paid to the hairy roots induced by the infection of agrobacterium rhizogenes in the production of plant secondary metabolic products for the hairy roots ar ... | 2004 | 15969111 |
| coniferyl alcohol, a lignin precursor, stimulates rhizobium rhizogenes a4 virulence. | rhizobium rhizogenes, a soil bacterium, is the causative agent of the neoplastic disease hairy root. upon incubation of rhizobium rhizogenes a4 with coniferyl alcohol, a lignin precursor, bacterial virulence on cotton cotyledon slices was stimulated. this was observed both in numbers of root hairs produced and in their length. stimulation was maximized after exposure of bacteria to 150 microg/ml of coniferyl alcohol for 4 h. this was shown to be at the early log phase of bacterial growth. | 2005 | 15886921 |
| single genes from agrobacterium rhizogenes influence plant development. | the combined expression of the rol a, b, and c loci of agrobacterium rhizogenes ri-plasmids establishes, in transgenic tobacco plants, a pathological state called hairy-root syndrome. however, when expressed separately they provoke distinct developmental abnormalities characteristic for each rol gene. moreover, changes in their mode of expression obtained by replacing the promoters of the rol b and c genes with the cauliflower mosaic virus 35s promoter elicit new and distinct developmental patte ... | 1988 | 15977331 |
| [establishment of saussurea involucrata hairy roots culture and plantlet regeneration]. | hairy root clones of saussurea involucrata transformed with agrobacterium rhizogenes strains r1601, r1000, and lba9402 were established to investigate the flavonoid production. opine synthesis and pcr analysis confirmed the integration of the t-dna fragment of ri plasmid from a. rhizogenes strain r1601 into the transformed root genome. the frequency of hairy root formation from root segments, which were pre-cultured 2 days in n6 solid medium without plant growth regulators, amounted to 100% foll ... | 2004 | 15971607 |
| production of antioxidant compounds by culture of panax ginseng c.a. meyer hairy roots: i. enhanced production of secondary metabolite in hairy root cultures by elicitation. | ginseng (panax ginseng c.a. meyer) hairy root cultures, established by infecting ginseng root discs with agrobacterium rhizogenes, were used for secondary metabolite production. in this study, several elicitors [salicylic acid (sa), acetylsalicylic acid (asa), yeast elicitor, and bacterial elicitor] were used to improve the productivity of useful metabolite in p. ginseng hairy root cultures. in sa elicitation, total ginseng saponin content increased slightly at lower elicitor dosages (0.1 to 0.5 ... | 2005 | 15930588 |
| qtls controlling the production of transgenic and adventitious roots in brassica oleracea following treatment with agrobacterium rhizogenes. | brassica oleracea can be genetically engineered using agrobacterium rhizogenes. the initial stage of this process is the production of transgenic ('hairy') roots; shoots are subsequently regenerated from these roots. previous work using gus and gfp reporter genes has shown that genotypes of b. oleracea vary in their performance for transgenic root production. quantitative trait loci (qtls) controlling this trait have been located in one mapping population. the current study provides evidence tha ... | 2005 | 15942754 |
| codon usage comparison of novel genes in clinical isolates of haemophilus influenzae. | a similarity statistic for codon usage was developed and used to compare novel gene sequences found in clinical isolates of haemophilus influenzae with a reference set of 80 prokaryotic, eukaryotic and viral genomes. these analyses were performed to obtain an indication as to whether individual genes were haemophilus-like in nature, or if they probably had more recently entered the h.influenzae gene pool via horizontal gene transfer from other species. the average and sd values were calculated f ... | 2005 | 15983137 |
| tolerance of transgenic canola expressing 1-aminocyclopropane-1-carboxylic acid deaminase to growth inhibition by nickel. | plant growth-promoting bacteria are useful to phytoremediation strategies in that they confer advantages to plants in contaminated soil. when plant growth-promoting bacteria contain the enzyme 1-aminocyclopropane-1-carboxylic acid (acc) deaminase, the bacterial cell acts as a sink for acc, the immediate biosynthetic precursor of the plant growth regulator ethylene thereby lowering plant ethylene levels and decreasing the negative effects of various environmental stresses. in an effort to gain th ... | 2005 | 16023358 |
| ectopic expression of the mycorrhiza-specific chitinase gene mtchit 3-3 in medicago truncatula root-organ cultures stimulates spore germination of glomalean fungi. | expression of mtchit 3-3, a class iii chitinase gene, is specifically induced by arbuscular mycorrhizal (am) fungi in roots of the model legume medicago truncatula and its transcripts accumulate in cells containing arbuscules. agrobacterium rhizogenes-transformed roots and root-organ cultures of m. truncatula were used to study effects of mtchit 3-3 on am fungi. * this work provides evidence for enzymatic activity of the mtchit 3-3 gene product and shows with promoter:gus fusions that a 2 kb fra ... | 2005 | 15998406 |
| ex vitro composite plants: an inexpensive, rapid method for root biology. | plant transformation technology is frequently the rate-limiting step in gene function analysis in non-model plants. an important tool for root biologists is the agrobacterium rhizogenes-derived composite plant, which has made possible genetic analyses in a wide variety of transformation recalcitrant dicotyledonous plants. the novel, rapid and inexpensive ex vitro method for producing composite plants described in this report represents a significant advance over existing composite plant inductio ... | 2005 | 16045479 |
| formation of organelle-like n2-fixing symbiosomes in legume root nodules is controlled by dmi2. | in most legume nodules, the n2-fixing rhizobia are present as organelle-like structures inside their host cells. these structures, named symbiosomes, contain one or a few rhizobia surrounded by a plant membrane. symbiosome formation requires the release of bacteria from cell-wall-bound infection threads. in primitive legumes, rhizobia are hosted in intracellular infection threads that, in contrast to symbiosomes, are bound by a cell wall. the formation of symbiosomes is presumed to represent a m ... | 2005 | 16006515 |
| [production of transgenic sugarbeet plants (beta vulgaris l.) using agrobacterium rhizogenes]. | normal phenotype sugarbeet plants transformed with agrobacterium rhizogenes were produced using direct regeneration from explants without hairy root phase. kanamycin resistant plants and ri-roots carrying the genes of neomycin phosphotransferase ii and b-glucuronidase have been obtained. integration of transgenes into sugarbeet genome was confirmed with gus-assay and pcr using primers for the introduced genes. | 2005 | 16018172 |
| enhanced secretion of tropane alkaloids in nicotiana tabacum hairy roots expressing heterologous hyoscyamine-6beta-hydroxylase. | hyoscyamine-6beta-hydroxylase (h6h; ec 1.14.11.11) catalyses oxidative reactions in the biosynthetic pathway leading from hyoscyamine to the more pharmaceutically valuable tropane alkaloid scopolamine. the h6h gene encoding h6h from hyoscyamus niger was introduced, under the control of the camv 35s promoter, into non-hyoscyamine-producing nicotiana tabacum and hyoscyamine-producing hyoscyamus muticus. the transformation was performed using a binary vector system based on agrobacterium rhizogenes ... | 2005 | 16105856 |
| the agrobacterium rhizogenes rolc-gene-induced somatic embryogenesis and shoot organogenesis in panax ginseng transformed calluses. | expression of the agrobacterium rhizogenes rolc gene in panax ginseng callus cells results in formation of tumors that are capable to form roots. the selection of non-root forming tumor clusters yielded the embryogenic 2c3 callus line, which formed somatic embryos and shoots independently of external growth factors. although the 2c3 somatic embryos developed through a typical embryogenesis process, they terminated prematurely and repeatedly formed adventitious shoot meristems and embryo-like str ... | 2006 | 16136334 |
| beta-carboline and quinoline alkaloids in root cultures and intact plants of peganum harmala. | alkaloid profiles of root and shoot cultures, seedlings and mature plants were analysed by capillary glc and glc-ms. beta-carboline alkaloids, such as harmine, harmaline dominate in normal and root cultures transformed by agrobacterium rhizogenes, as well as in roots and fruits of the plant. in shoots, flowers and shoot cultures quinoline alkaloids such as peganine, deoxypeganine, vasicinone and deoxyvasicinone widely replace the beta-carboline alkaloids. in root cultures, the formation of beta- ... | 2005 | 16042347 |
| hairy root cultures of gynostemma pentaphyllum (thunb.) makino: a promising approach for the production of gypenosides as an alternative of ginseng saponins. | hairy root cultures of gynostemma pentaphyllum were established by infecting leaf discs with agrobacterium rhizogenes. the dry biomass of hairy roots grown in ms medium for 49 days was 7.3 g l(-1) with a gypenoside content of 38 mg g(-1) dry wt. | 2005 | 16158258 |
| organization and metabolism of plastids and mitochondria in arbuscular mycorrhizal roots of medicago truncatula. | colonization of root cortical cells by arbuscular mycorrhizal fungi leads to marked cytological changes of plastids and mitochondria. plastids in particular are forming tubular extensions partially connecting individual organelles in a network-like way. these cytological changes correspond to an increased need for plastid and mitochondrial products during establishment and functioning of the symbiosis. the analysis of metabolite and transcript levels in mycorrhizal and nonmycorrhizal roots from ... | 2005 | 16126866 |
| suppression of allene oxide cyclase in hairy roots of medicago truncatula reduces jasmonate levels and the degree of mycorrhization with glomus intraradices. | during the symbiotic interaction between medicago truncatula and the arbuscular mycorrhizal (am) fungus glomus intraradices, an endogenous increase in jasmonic acid (ja) occurs. two full-length cdnas coding for the ja-biosynthetic enzyme allene oxide cyclase (aoc) from m. truncatula, designated as mtaoc1 and mtaoc2, were cloned and characterized. the aoc protein was localized in plastids and found to occur constitutively in all vascular tissues of m. truncatula. in leaves and roots, mtaocs are e ... | 2005 | 16244141 |
| plant-derived transfer dnas. | the transfer of dna from agrobacterium to plant cell nuclei is initiated by a cleavage reaction within the 25-bp right border of ti plasmids. in an effort to develop all-native dna transformation vectors, 50 putative right border alternatives were identified in both plant expressed sequence tags and genomic dna. efficacy tests in a tobacco (nicotiana tabacum) model system demonstrated that 14 of these elements displayed at least 50% of the activity of conventional agrobacterium transfer dna bord ... | 2005 | 16244143 |
| green fluorescent protein as an efficient selection marker for agrobacterium rhizogenes mediated carrot transformation. | agrobacterium rhizogenes mediated transformation combined with a visual selection for green fluorescent protein (gfp) has been applied effectively in carrot (daucus carota l.) transformation. carrot root discs were inoculated with a4, a4t, lba1334 and lba9402 strains, all bearing gfp gene in pbin-m-gfp5-er. the results indicate that transformed adventitious roots can be visually selected solely based on gfp fluorescence with a very high accuracy. the method requires no selection agents like anti ... | 2006 | 16247612 |
| [hairy root induced by wild-type agrobacterium rhizogenes k599 in soybean, cucumber and garden balsam in vivo]. | the plantlets of soybean, cucumber and garden balsam were inoculated by wild-type agrobacterium rhizogenes k599, and hairy root was induced on inoculated sites in vivo. the frequencies of hairy root induction from wound cotyledons of soybean, cucumber and garden balsam were 100%, 65% and 91%, respectively. moreover, hairy root was induced from healthy cucumber axillary bud with frequency of 10%. pcr analysis of hairy root dna was conducted using the primers from rolc gene. the pcr results showed ... | 2005 | 16257909 |
| terpenoid indole alkaloid production by catharanthus roseus hairy roots induced by agrobacterium tumefaciens harboring rol abc genes. | we have established catharanthus roseus hairy root cultures transgenic for the rol abc genes from t(l)-dna of the agropine-type agrobacterium rhizogenes strain a4. the rol abc hairy root lines exhibit a wild-type hairy root syndrome in terms of growth and morphology on solid medium. however, they differ from wild-type hairy root lines in that they more frequently have excellent adaptability to liquid medium and do not appear to form calli during cultivation. moreover, they do not produce detecta ... | 2006 | 16261632 |
| overexpression of arabidopsis phytochelatin synthase in tobacco plants enhances cd(2+) tolerance and accumulation but not translocation to the shoot. | phytochelatins (pcs) are metal binding peptides involved in heavy metal detoxification. to assess whether enhanced phytochelatin synthesis would increase heavy metal tolerance and accumulation in plants, we overexpressed the arabidopsis phytochelatin synthase gene (atpcs1) in the non-accumulator plant nicotiana tabacum. wild-type plants and plants harbouring the agrobacterium rhizogenes rolb oncogene were transformed with a 35s atpcs1 construct. root cultures from rolb plants could be easily est ... | 2006 | 16133212 |
| transgenic proteoid roots of white lupin: a vehicle for characterizing and silencing root genes involved in adaptation to p stress. | white lupin (lupinus albus l.) has become an illuminating model for the study of plant adaptation to phosphorus (p) deficiency. it adapts to -p stress with a highly coordinated modification of root development and biochemistry resulting in short, densely clustered secondary roots called proteoid (or cluster) roots. in order to characterize genes involved in proteoid root formation and function in a homologous system, we have developed an agrobacterium rhizogenes-based transformation system for w ... | 2005 | 16297074 |
| biogenesis, architecture, and function of bacterial type iv secretion systems. | type iv secretion (t4s) systems are ancestrally related to bacterial conjugation machines. these systems assemble as a translocation channel, and often also as a surface filament or protein adhesin, at the envelopes of gram-negative and gram-positive bacteria. these organelles mediate the transfer of dna and protein substrates to phylogenetically diverse prokaryotic and eukaryotic target cells. many basic features of t4s are known, including structures of machine subunits, steps of machine assem ... | 2005 | 16153176 |
| characterization of lucidin formation in rubia tinctorum l. | in order to approach lucidin formation (a strong mutagen or a carcinogen) from a physiological standpoint, hairy roots of rubia tinctorum l. were established by a transformation of agrobacterium rhizogenes strain 15834 and cultured in a liquid woody plant medium without plant hormones. the anthraquinone pigment composition of the intact hairy roots was essentially the same as that of the intact non-transformed (normal) roots, in which lucidin o-beta-d-primeveroside (lup) was one of the major pig ... | 2005 | 16310368 |
| amplified fragment length polymorphism and metabolomic profiles of hairy roots of psoralea corylifolia l. | a reproducible protocol for establishment of hairy root cultures of psoralea corylifolia l. was developed using agrobacterium rhizogenes strain atcc 15834. the hairy root clones exhibited typical sigmoid growth curves. genomic and metabolomic profiles of hairy root clones along with that of untransformed control were analysed. hairy root clones, ps i and ps ii, showed significant differences in their amplified fragment length polymorphism (aflp) profiles as compared to that of control, besides e ... | 2005 | 16169025 |
| arbuscular mycorrhizal fungi elicit a novel intracellular apparatus in medicago truncatula root epidermal cells before infection. | the penetration of arbuscular mycorrhizal (am) fungi through the outermost root tissues of the host plant is a critical step in root colonization, ultimately leading to the establishment of this ecologically important endosymbiotic association. to evaluate the role played by the host plant during am infection, we have studied in vivo cellular dynamics within medicago truncatula root epidermal cells using green fluorescent protein labeling of both the plant cytoskeleton and the endoplasmic reticu ... | 2005 | 16284314 |
| induction of thioredoxin is required for nodule development to reduce reactive oxygen species levels in soybean roots. | nodules are formed on legume roots as a result of signaling between symbiotic partners and in response to the activities of numerous genes. we cloned fragments of differentially expressed genes in spot-inoculated soybean (glycine max) roots. many of the induced clones were similar to known genes related to oxidative stress, such as thioredoxin and beta-carotene hydroxylase. the deduced amino acid sequences of full-length soybean cdnas for thioredoxin and beta-carotene hydroxylase were similar to ... | 2005 | 16299179 |
| degradation of the herbicide glyphosate by members of the family rhizobiaceae. | several strains of the family rhizobiaceae were tested for their ability to degrade the phosphonate herbicide glyphosate (isopropylamine salt of n-phosphonomethylglycine). all organisms tested (seven rhizobium meliloti strains, rhizobium leguminosarum, rhizobium galega, rhizobium trifolii, agrobacterium rhizogenes, and agrobacterium tumefaciens) were able to grow on glyphosate as the sole source of phosphorus in the presence of the aromatic amino acids, although growth on glyphosate was not as f ... | 1991 | 16348512 |
| analysis of mycorrhizal associations formed by cistus incanus transformed root clones with terfezia boudieri isolates. | one clone (m-2), out of several agrobacterium rhizogenes transformed root clones of cistus incanus, formed ecto- or endomycorrhiza in vitro with two isolates of terfezia boudieri collected in israel. all other clone-fungal isolate combinations formed ectomycorrhiza. the endomycorrhiza-forming isolate secreted smaller amounts of auxin than an ectomycorrhiza-forming isolate. addition of 2,4-dichlorophenoxyacetic acid (2,4-d) led to ectomycorrhiza formation by the m-2 clone on low p medium. endomyc ... | 2006 | 16322996 |
| transgenic plants regenerated from hairy roots of nicotiana benthamiana: a promising host for transient expression of foreign proteins. | hairy root cultures of nicotiana benthamiana have been obtained by co-cultivation of leaf explants with agrobacterium rhizogenes strain a4 harboring a binary vector plasmid, and transgenic nature of the obtained cultures was confirmed by pcr analysis. transgenic plants were regenerated from hairy roots. the biomass yield of transgenic plants grown in vitro was almost two-fold higher than those of wild-type n. benthamiana plants. they differed from untransformed plants by short internodes, reinfo ... | 2005 | 16396315 |
| genista tinctoria hairy root cultures for selective production of isoliquiritigenin. | hairy root cultures were established after inoculation of genista tinctoria in vitro shoots with agrobacterium rhizogenes, strain atcc 15834. in transformed roots of g. tinctoria grown in schenk-hildebrandt medium without growth regulators the biosynthesis of isoflavones, derivatives of genistein and daidzein, and flavones, derivatives of luteolin and apigenin, characteristic for the intact plant, was completely inhibited. the only compound synthesized in g. tinctoria hairy roots was isoliquirit ... | 2005 | 16402547 |
| a nucleoporin is required for induction of ca2+ spiking in legume nodule development and essential for rhizobial and fungal symbiosis. | nuclear-cytoplasmic partitioning and traffic between cytoplasmic and nuclear compartments are fundamental processes in eukaryotic cells. nuclear pore complexes mediate transport of proteins, rnas and ribonucleoprotein particles in and out of the nucleus. here we present positional cloning of a plant nucleoporin gene, nup133, essential for a symbiotic signal transduction pathway shared by rhizobium bacteria and mycorrhizal fungi. mutation of nup133 results in a temperature sensitive nodulation de ... | 2006 | 16407163 |
| overexpression of the saussurea medusa chalcone isomerase gene in s. involucrata hairy root cultures enhances their biosynthesis of apigenin. | saussurea involucrata is a medicinal plant well known for its flavonoids, including apigenin, which has been shown to significantly inhibit tumorigenesis. since naturally occurring apigenin is in very low abundance, we took a transgenic approach to increase apigenin production by engineering the flavonoid pathway. a construct was made to contain the complete cdna sequence of the saussurea medusa chalcone isomerase (chi) gene under the control of the cauliflower mosaic virus (camv) 35s promoter. ... | 2006 | 16427667 |
| isolation and identification of tl-dna/plant junctions in convolvulus arvensis transformed by agrobacterium rhizogenes strain a4. | we have constructed a charon 4a phage library containing insert dna isolated from a morning glory (convolvulus arvensis) plant (clone 7) regenerated from a root organ culture incited by agrobacterium rhizogenes, strain a4. using a subcloned region of the ri plasmid as p-labeled probe, two lambda clones containing most of the 'left' t-dna (tl) region were isolated. one of these lambda clones contains the left tl-dna/plant junction, which was located by comparing nucleotide sequences from the appr ... | 1985 | 16453649 |
| localization of agrobacterium rhizogenes t-dna in plant chromosomes by in situ hybridization. | we have used in situ hybridization to determine the sites of insertion of agrobacterium rhizogenes ri t-dna in the chromosomes of crepis capillaris (2n = 6) transformed roots. four transformed root lines were obtained by infecting crepis stem segments with a. rhizogenes. southern hybridization analysis indicated that each root line was the result of one or more independent t-dna insertion events. in two root lines, one copy of t-dna was present; the other two root lines each contained two copies ... | 1986 | 16453703 |
| independent and synergistic activity of rol a, b and c loci in stimulating abnormal growth in plants. | the ri plasmid a4 of agrobacterium rhizogenes contains within its t-dna genetic information able to trigger root formation in infected plants. tobacco plants regenerated from transformed roots display the hairy root (hr) syndrome. we show that dna fragments containing the rol b locus alone are able to induce root formation both in tobacco and kalanchoe tissues. the rol a and the rol c loci by themselves are also able to induce root formation in tobacco but not in kalanchoe. this capacity to indu ... | 1987 | 16453816 |
| the coexistence of symbiosis and pathogenicity-determining genes in rhizobium rhizogenes strains enables them to induce nodules and tumors or hairy roots in plants. | bacteria belonging to the family rhizobiaceae may establish beneficial or harmful relationships with plants. the legume endosymbionts contain nod and nif genes responsible for nodule formation and nitrogen fixation, respectively, whereas the pathogenic strains carry vir genes responsible for the formation of tumors or hairy roots. the symbiotic and pathogenic strains currently belong to different species of the genus rhizobium and, until now, no strains able to establish symbiosis with legumes a ... | 2005 | 16478052 |
| [effects of light and plant growth regulators on growth of normal and hairy root of lycium barbarum in vitro]. | to study effects of the cycle of light and exogenous plant growth regulators on growth of normal root and hairy root of lycium barbarum and establish a long-term system of in vitro culture of l. barbarum roots. | 2006 | 16570792 |
| [hairy root induction and plant regeneration of crownvetch (coronilla varia l.) transformed by agrobacterium rhizogenes]. | an efficient system of genetic transformation and plant regeneration via somatic embryogenesis was established in crownvetch (coronilla varia l.) by infecting the segments of cotyledons and hypocotyls of 15d-old seedlings with agrobacterium rhizogenes strain 15834. hairy roots were produced directly from the wounded surface of the explants or via calluses on hormone-free murashige and skoog (ms) medium after infection by a. rhizogenes. transformed roots grew rapidly either on solid or liquid ms ... | 2006 | 16572849 |
| [studies on chemical constituents of hairy root of cassia obtusifolia]. | to study the chemical constituents in hairy roots of cassia obtusifolia. | 2006 | 16573002 |
| stable transformation and direct regeneration in coffea canephora p ex. fr. by agrobacterium rhizogenes mediated transformation without hairy-root phenotype. | a system for genetic transformation of coffea canephora by co-cultivation with agrobacterium rhizogenes harbouring a binary vector has been developed. the objective of the present study was the genetic transformation and direct regeneration of transformants through secondary embryos bypassing an intervening hairy root stage. transformants were obtained with a transformation efficiency up to 3% depending on the medium adjuvant used. a. rhizogenes strain a4 harbouring plasmid pcambia 1301 with an ... | 2006 | 16331458 |
| thymol derivatives from hairy roots of arnica montana. | five known thymol derivatives were isolated from roots of arnica montana transformed with agrobacterium rhizogenes lba 9402. the compounds were characterized by spectral methods. the pattern of thymol derivatives in light-grown hairy roots was slightly different from that in dark-grown ones. this is the first report on the presence of thymol derivatives in hairy roots of the plant. | 2006 | 16586074 |
| rapid and specific identification of four agrobacterium species and biovars using multiplex pcr. | on the basis of 23s rrna gene sequences, 1 universal forward and 4 taxon (species/biovar)-specific reverse primers were designed for multiplex pcr to aid in identification and differentiation of agrobacterium rubi, agrobacterium vitis and agrobacterium biovars 1 and 2. in reactions with dna of 119 bacterial strains belonging to: agrobacterium, allorhizobium, mesorhizobium, rhizobium, sinorhizobium and phyllobacterium, as well as phytopathogenic bacteria representing various genera, the primers d ... | 2006 | 16343837 |
| transcript analysis of early nodulation events in medicago truncatula. | within the first 72 h of the interaction between rhizobia and their host plants, nodule primordium induction and infection occur. we predicted that transcription profiling of early stages of the symbiosis between medicago truncatula roots and sinorhizobium meliloti would identify regulated plant genes that likely condition key events in nodule initiation. therefore, using a microarray with about 6,000 cdnas, we compared transcripts from inoculated and uninoculated roots corresponding to defined ... | 2006 | 16377745 |
| transgenic medicago truncatula plants obtained from agrobacterium tumefaciens -transformed roots and agrobacterium rhizogenes-transformed hairy roots. | medicago truncatula, barrel medic, is a forage crop that has been developed into a model legume. the development of new transformation methods is important for functional genomic studies in this species. based on agrobacterium tumefaciens-mediated transformation of root explants, we developed an effective system for producing m. truncatula (genotype r108) transgenic plants. among the four a. tumefaciens strains (agl1, c58c1, eha105 and lba4404) tested, eha105 and agl1 were most effective in rege ... | 2006 | 16575594 |
| tumor induction by agrobacterium rhizogenes involves the transfer of plasmid dna to the plant genome. | the dna from tumors of nicotiana glauca initiated by strains of agrobacterium rhizogenes was shown to contain sequences that are homologous to the root-inducing (ri) plasmid of the bacterium. two independently established tumor lines contained a similar portion of the ri-plasmid. the ri-plasmid also hybridized to dna fragments from uninfected n. glauca. a cosmid clone of the ri-plasmid encompassing the region containing the ri-plasmid sequences that are stably transferred to the plant also hybri ... | 1982 | 16593190 |
| hairy roots are more sensitive to auxin than normal roots. | responses to auxin of lotus corniculatus root tips or protoplasts transformed by agrobacterium rhizogenes strains 15834 and 8196 were compared to those of their normal counterparts. three different types of experiments were performed, involving long-term, medium-term, or short-term responses to a synthetic auxin, 1-naphthaleneacetic acid. root tip elongation, proton excretion by root tips, and transmembrane electrical potential difference of root protoplasts were measured as a function of exogen ... | 1988 | 16593928 |
| heterologous expression of vitreoscilla hemoglobin (vhb) and cultivation conditions affect the alkaloid profile of hyoscyamus muticus hairy roots. | fast-growing hairy root cultures of hyoscyamus muticus induced by agrobacterium rhizogenes offer a potential production system for tropane alkaloids. oxygen deficiency has been shown to limit growth and biomass accumulation of hairy roots, whereas little experimental data is available on the effect of oxygen on alkaloid production. we have investigated the effect of vitreoscilla hemoglobin (vhb) expression and cultivation conditions on the complete alkaloid profile of h. muticus hairy roots in s ... | 2006 | 16599546 |
| spontaneous plant regeneration in transformed roots and calli from tylophora indica: changes in morphological phenotype and tylophorine accumulation associated with transformation by agrobacterium rhizogenes. | we examined the effects of genetic transformation by agrobacterium rhizogenes on the production of tylophorine, a phenanthroindolizidine alkaloid, in the indian medicinal plant, tylophora indica. transformed roots induced by the bacterium grew in axenic culture and produced shoots or embryogenic calli in the absence of hormone treatments. however, hormonal treatment was required to regenerate shoots in root explants of wild type control plants. transformed plants showed morphological features ty ... | 2006 | 16609889 |
| hairy root research: recent scenario and exciting prospects. | high stability of the production of secondary metabolites is an interesting characteristic of hairy root cultures. for 25 years, hairy roots have been investigated as a biological system for the production of valuable compounds from medicinal plants. a better understanding of the molecular mechanism of hairy root development, which is based on the transfer of agrobacterium rhizogenes t-dna into the plant genome, has facilitated its increasing use in metabolic engineering. hairy roots can also pr ... | 2006 | 16616871 |
| complementation of agrobacterium tumefaciens tumor-inducing aux mutants by genes from the t(r)-region of the ri plasmid of agrobacterium rhizogenes. | in this paper we provide information indicating that the agropine-type root-inducing (ri) plasmid pri1855 of agrobacterium rhizogenes contains functional genes for auxin production (aux) in the right transferred dna (t-dna) region (t(r)-region). these genes were cloned and introduced into the t-region of the tumor-inducing (ti) plasmids of mutants of agrobacterium tumefaciens carrying an aux mutation. depending on the ri aux gene present, the oncogenicity of the ti aux-1 and/or aux-2 mutations w ... | 1986 | 16593762 |
| genotypic variability of soybean response to agrobacterium strains harboring the ti or ri plasmids. | twenty four diverse cultivars of soybean (glycine max [l.] merrill) and three lines of its annual wild progenitor glycine soja sieb and zucc. were tested for their response to agrobacterium strains harboring either the ti (tumor-inducing) plasmid (pti) from agrobacterium tumefaciens or the ri (root-inducing) plasmid (pri) from agrobacterium rhizogenes following uniform wounding and inoculation. based upon gall weight at 8 weeks postinfection, three g. max cultivars (biloxi, jupiter, and peking) ... | 1985 | 16664035 |
| response of various cucurbits to infection by plasmid-harboring strains of agrobacterium. | tumor formation in cucurbit cultivars resulting from infection by various strains of agrobacterium tumefaciens and agrobacterium rhizogenes is environmentally affected. in all instances, tumors could be induced on excised cotyledons while inoculating attached cotyledons or stems resulted in no tumor formation. in addition, buttercup squash (cucurbita maxima duch. buttercup) was most susceptible to tumor formation, while butterbush squash (cucurbita maxima duch. butterbush) failed to form tumors ... | 1986 | 16665082 |
| reversion of aberrant plants transformed with agrobacterium rhizogenes is associated with the transcriptional inactivation of the t(l)-dna genes. | transgenic plants harboring the left transfer dna (t(l)-dna) of the root inducing plasmid of agrobacterium rhizogenes show many developmental abnormalities. we observed frequent appearance of normal looking lateral (revertant) shoots from such aberrant plants. unlike aberrant shoots of the plant, revertant shoots exhibited a very high growth rate and set viable seeds. sexual and vegetative reproduction studies showed inheritance of the revertant phenotype. southern hybridization experiments demo ... | 1988 | 16665950 |
| crown gall disease and hairy root disease : a sledgehammer and a tackhammer. | the neoplastic diseases crown gall and hairy root are incited by the phytopathogenic bacteria agrobacterium tumefaciens and agrobacterium rhizogenes, respectively. although the molecular mechanism of t-dna transfer to the plant most likely is the same for both species, the physiological basis of tumorigenesis is fundamentally different. crown gall tumors result from the over-production of the phytohormones auxin and cytokinin specified by a. tumefaciens t-dna genes. although the t-dna of some ri ... | 1990 | 16667272 |
| inverse relationship between polyamine levels and the degree of phenotypic alteration induced by the root-inducing, left-hand transferred dna from agrobacterium rhizogenes. | floral induction in plants is a paradigm for signal perception, transduction, and physiological response. the introduction of root-inducing, left-hand transferred dna (ri t-dna) into the genomes of several plants results in modifications of flowering (d tepfer [1984] cell 47: 959-967), including a delay in flowering in tobacco (nicotiana tabacum). conjugated polyamines are markers for flowering in numerous species of plants. in tobacco their accumulation is correlated with the onset of flowering ... | 1990 | 16667405 |
| high sensitivity to auxin is a common feature of hairy root. | the responses to auxin of lycopersicon esculentum roots transformed by (t(l)+t(r))-dna of the ri plasmid of agropine-type agrobacterium rhizogenes strain 15834 and catharanthus trichophyllus roots transformed by the (t(l)+t(r))-dna, and by t(l)- or t(r)- dna alone of the same bacterial strain were compared to that of their normal counterparts. the transmembrane electrical potential difference of root protoplasts was measured as a function of the concentration of exogenous naphthalene acetic acid ... | 1990 | 16667748 |
| alpha-dl-difluoromethylornithine, a specific, irreversible inhibitor of putrescine biosynthesis, induces a phenotype in tobacco similar to that ascribed to the root-inducing, left-hand transferred dna of agrobacterium rhizogenes. | alpha-dl-difluoromethylarginine (dfma) and alpha-dl-difluoromethylornithine (dfmo), specific irreversible inhibitors of putrescine biosynthesis were applied to nicotiana tabacum var. xanthi nc during floral induction. dfmo, but not dfma, induced a phenotype in tobacco that resembles the transformed phenotype attributed to the root-inducing, left-hand, transferred dna of agrobacterium rhizogenes, including wrinkled leaves, shortened internodes, reduced apical dominance, and retarded flowering. si ... | 1991 | 16668006 |
| inhibition by ethylene of auxin-promotion of flower bud formation in tobacco explants is absent in plants transformed by agrobacterium rhizogenes. | the in vitro regeneration of flower buds was studied in pedicel explants from tobacco (nicotiana tabacum l., cv petit havana) transformed with agrobacterium rhizogenes, pri 1855 (agropine type). at a low concentration (0.1 micromolar) of 1-naphthalene-acetic acid, pedicel strips from phenotypically aberrant plants regenerated two to three times more flower buds than explants from untransformed tobacco. intermediate bud numbers were observed in transformants with a less extreme phenotype. the res ... | 1991 | 16668309 |
| single rol genes from the agrobacterium rhizogenes t(l)-dna alter some of the cellular responses to auxin in nicotiana tabacum. | two kinds of cellular responses to auxin, the hyperpolarization of protoplasts and the division of protoplast-derived cells, were compared in nicotiana tabacum plants transformed by different t-dna fragments of agrobacterium rhizogenes strain a4. using transmembrane potential difference measurements to characterize hormonal sensitivity of mesophyll protoplasts, we found a 30-fold increase in sensitivity to auxin in protoplasts transformed by the whole ri a4 t-dna. furthermore, the rol genes of t ... | 1991 | 16668373 |
| induction of pseudoactinorhizae by the plant pathogen agrobacterium rhizogenes. | infection of elaeagnus angustifolia cotyledonary wounds by agrobacterium rhizogenes strain ncppb 2659 resulted in the formation of pseudoactinorhizae on roots differentiated from callus. these pseudoactinorhizal root nodules were anatomically indistinguishable from the actinorhizae induced by the plant's microsymbiont frankia. this unusual hairy root phenotype provides support for the concept that the genetic program for actinorhiza morphogenesis resides in the plant's genome. | 1992 | 16668712 |
| hormone-resistant mutants of arabidopsis have an attenuated response to agrobacterium strains. | we have examined the response of the hormone-resistant mutants axr1 and axr2 of arabidopsis thaliana to inoculation by agrobacterium tumefaciens and agrobacterium rhizogenes. our results indicate that recessive mutations in the axr1 gene affect the frequency of tumor formation after inoculation with either agrobacterium strain. in addition, tumors produced on axr1 plants were smaller than those growing on wild-type plants. these results indicate that the product of the axr1 gene is important for ... | 1992 | 16668774 |
| deletion analysis of the 5'-upstream region of the agrobacterium rhizogenes ri plasmid rolc gene required for tissue-specific expression. | the cis-acting elements located in the -848 and +23 region of the 5'-upstream region of the rolc gene of the agrobacterium rhizogenes ri plasmid were investigated. the cis-acting dna region required for phloem-specific expression was found within the -153 region, whereas a minimum region needed for the expression in the seed embryo was located at position -120. | 1992 | 16668908 |
| light requirement for shoot regeneration in horseradish hairy roots. | hairy roots of horseradish (armoracia rusticana) were induced by inoculation with agrobacterium rhizogenes harboring ri plasmid and cultured on phytohormone-free murashige and skoog medium after eliminating the bacteria. hairy roots grew vigorously and sometimes formed yellowish calli under dark conditions. on the other hand, growth of hairy roots stopped after several weeks of culture with light, then shoots were regenerated. frequency of shoot formation from hairy roots increased as the cultur ... | 1992 | 16669041 |
| expression of a complete soybean leghemoglobin gene in root nodules of transgenic lotus corniculatus. | the complete soybean leghemoglobin lbc(3) gene was transferred into the legume lotus corniculatus using an agrobacterium rhizogenes vector system. organ-specific expression of the soybean gene was observed in root nodules formed on regenerated transgenic plants after infection with rhizobium loti. the primary transcript was processed in the same way as in soybean nodules and the resulting mrna was translated into lbc(3) protein. quantitative determination of the lbc(3) protein in nodules of tran ... | 1987 | 16593870 |
| sequence analysis of the 144-kilobase accessory plasmid psmesm11a, isolated from a dominant sinorhizobium meliloti strain identified during a long-term field release experiment. | the genome of sinorhizobium meliloti type strain rm1021 consists of three replicons: the chromosome and two megaplasmids, psyma and psymb. additionally, many indigenous s. meliloti strains possess one or more smaller plasmids, which represent the accessory genome of this species. here we describe the complete nucleotide sequence of an accessory plasmid, designated psmesm11a, that was isolated from a dominant indigenous s. meliloti subpopulation in the context of a long-term field release experim ... | 2006 | 16672515 |
| bases of biocontrol: sequence predicts synthesis and mode of action of agrocin 84, the trojan horse antibiotic that controls crown gall. | agrobacterium radiobacter k84, used worldwide to biocontrol crown gall disease caused by agrobacterium tumefaciens, produces an antiagrobacterial compound called agrocin 84. we report the nucleotide sequence of pagk84, a 44.42-kb plasmid coding for production of this disubstituted adenine nucleotide antibiotic. pagk84 encodes 36 orfs, 17 of which (agn) code for synthesis of or immunity to agrocin 84. two genes, agnb2 and agna, encode aminoacyl trna synthetase homologues. we have shown that the t ... | 2006 | 16731618 |
| the genome of rhizobium leguminosarum has recognizable core and accessory components. | rhizobium leguminosarum is an alpha-proteobacterial n2-fixing symbiont of legumes that has been the subject of more than a thousand publications. genes for the symbiotic interaction with plants are well studied, but the adaptations that allow survival and growth in the soil environment are poorly understood. we have sequenced the genome of r. leguminosarum biovar viciae strain 3841. | 2006 | 16640791 |
| efficient production of agrobacterium rhizogenes-transformed roots and composite plants for studying gene expression in coffee roots. | the possibility of rapid validation and functional analysis of nematode resistance genes is a common objective for numerous species and particularly for woody species. in this aim, we developed an agrobacterium rhizogenes-mediated transformation protocol for coffea arabica enabling efficient and rapid regeneration of transformed roots from the hypocotyls of germinated zygotic embryos, and the subsequent production of composite plants. the a. rhizogenes strain a4rs proved to be the most virulent. ... | 2006 | 16596429 |
| [induction of cucumber hairy roots and effect of cytokinin 6-ba on its growth and morphology]. | hairy roots of cucumis sativus l. could be incited directly from the cut edges of 10-day-old cotyledon explants after infection with the strain agrobacterium rhizogenes atcc15834 harboring agropine-type plasmid, pria4b for 5 days. it was observed that the percentage of rooting cotyledon explants was more than 90 % 10 days after infection. hairy roots could grow rapidly and highly branched on solid plant growth regulator-free ms medium. the pcr amplification of rol b genes and vir c gene showed t ... | 2006 | 16755937 |
| the shikonin derivatives and pyrrolizidine alkaloids in hairy root cultures of lithospermum canescens (michx.) lehm. | hairy root cultures of lithospermum canescens were established using three strains of agrobacterium rhizogenes: atcc 15834, lba 9402 and ncib 8196. eight lines resulting from infection with a. rhizogenes atcc 15834 demonstrated sufficient biomass increase and were submitted to further investigations. the contents of acetylshikonin (acs) and isobutyrylshikonin (ibs) in transformed hairy roots made up ca. 10% of those observed in natural roots of l. canescens (24.35 and 14.48 mg g(-1) dw, respecti ... | 2006 | 16670900 |
| silencing the flavonoid pathway in medicago truncatula inhibits root nodule formation and prevents auxin transport regulation by rhizobia. | legumes form symbioses with rhizobia, which initiate the development of a new plant organ, the nodule. flavonoids have long been hypothesized to regulate nodule development through their action as auxin transport inhibitors, but genetic proof has been missing. to test this hypothesis, we used rna interference to silence chalcone synthase (chs), the enzyme that catalyzes the first committed step of the flavonoid pathway, in medicago truncatula. agrobacterium rhizogenes transformation was used to ... | 2006 | 16751348 |
| production of triterpenoids in liquid-cultivated hairy roots of galphimia glauca. | the production of three triterpenoids from galphimia glauca hairy root cultures, the sedative principle galphimine e (2), the recently described glaucacetalin a (3), and maslinic acid (6), was quantified by hplc in the biomass and the culture medium. batch cultures of the hairy root line vyt, obtained through infecting cotyledons with agrobacterium rhizogenes atcc 15 834, were grown for 41 days in shake flasks containing b5 medium without phytohormones. a maximum biomass of 11 g/l dw was obtaine ... | 2006 | 16732534 |
| glyphosate-induced anther indehiscence in cotton is partially temperature dependent and involves cytoskeleton and secondary wall modifications and auxin accumulation. | yield reduction caused by late application of glyphosate to glyphosate-resistant cotton (gossypium hirsutum; grc) expressing cp4 5-enol-pyruvylshikmate-3-p synthase under the cauliflower mosaic virus-35s promoter has been attributed to male sterility. this study was aimed to elucidate the factors and mechanisms involved in this phenomenon. western and tissue-print blots demonstrated a reduced expression of the transgene in anthers of grc compared to ovules of the same plants. glyphosate applicat ... | 2006 | 16766672 |
| genetic transformation of centaurium erythraea rafn by agrobacterium rhizogenes and the production of secoiridoids. | hairy roots of centaurium erythraea were obtained by infection with agrobacterium rhizogenes strain lba 9402. they spontaneously regenerated adventitious shoots in woody plant liquid medium without growth regulators. the shoots were grown continuously in murashige and skoog (ms) liquid or agar solidified media supplemented with 0.1 mg l(-1) indole-3-acetic acid and 1.0 mg l(-1) 6-benzylaminopurine. these shoots produced roots 4 weeks after transfer into agar-solidified ms medium without phytohor ... | 2006 | 16841219 |
| the medicago truncatula lysin [corrected] motif-receptor-like kinase gene family includes nfp and new nodule-expressed genes. | rhizobial nod factors are key symbiotic signals responsible for starting the nodulation process in host legume plants. of the six medicago truncatula genes controlling a nod factor signaling pathway, nod factor perception (nfp) was reported as a candidate nod factor receptor gene. here, we provide further evidence for this by showing that nfp is a lysin [corrected] motif (lysm)-receptor-like kinase (rlk). nfp was shown both to be expressed in association with infection thread development and to ... | 2006 | 16844829 |
| effects of endogenous salicylic acid on nodulation in the model legumes lotus japonicus and medicago truncatula. | the exogenous addition of salicylic acid (sa) was previously shown to inhibit indeterminate but not determinate-type nodulation. we sought to extend these results by modulating endogenous levels of sa through the transgenic expression of salicylate hydroxylase (nahg) in both stably transformed lotus japonicus and composite medicago truncatula plants. nahg expression in l. japonicus resulted in a marked reduction of sa levels. this reduction correlated with an increase in the number of infections ... | 2006 | 16798946 |
| expression of recombinant digitalis lanata ehrh. cardenolide 16'-o-glucohydrolase in cucumis sativus l. hairy roots. | the coding sequence for the digitalis lanata ehrh. cardenolide 16'-o-glucohydrolase was inserted downstream of the 35s promoter in the binary vector pbi121 resulting in plant expression vector pbi121cgh. cotyledon explants excised from 10-day-old seedlings of cucumis sativus l. were transformed using agrobacterium rhizogenes 15834 harbouring pbi121cgh. hairy roots were obtained from infected cotyledon explants in vitro 10 days after inoculation. pcr amplification of coding sequences for cgh i, r ... | 2006 | 16775721 |
| tailoring tropane alkaloid accumulation in transgenic hairy roots of atropa baetica by over-expressing the gene encoding hyoscyamine 6beta-hydroxylase. | atropa baetica hairy roots, over-expressing cdna from hyoscyamus niger encoding the gene for hyoscyamine 6beta-hydroxylase (h6h), were produced by agrobacterium rhizogenes infection. the transgenic roots over-expressing h6h had an altered alkaloid profile in which hyoscyamine was entirely converted into scopolamine. in the best h6h clone, scopolamine accumulation increased 9-fold compared to plants, amounting to 5.6 mg g dry wt(-1), some of which was released into the liquid medium. only negligi ... | 2006 | 16802099 |
| high-efficiency agrobacterium rhizogenes-mediated transformation of heat inducible shsp18.2-gus in nicotiana tabacum. | the chimerical gene, arabidopsis thaliana shsp18.2 promoter fused to e. coli gusa gene, was agrobacterium rhizogenes-mediated transformed into nicotiana tabacum as a heat-regulatable model, and the thermo-inducible expression of gus activity in n. tabacum transgenic hairy roots was profiled. an activation of a. rhizogenes with acetosyringone (as) before cocultured with tobacco's leaf disc strongly promoted transgenic hairy roots formation. transgenic hairy roots formation efficiency of a. rhizog ... | 2007 | 16874528 |
| biotransformation of hyoscyamine into scopolamine in transgenic tobacco cell cultures. | hyoscyamine-6beta-hydroxylase (h6h) catalyses the conversion of hyoscyamine into its epoxide scopolamine, a compound with a higher added value in the pharmaceutical market than hyoscyamine. we report the establishment of tobacco cell cultures carrying the hyoscyamus muticus h6h gene under the control of the promoter camv 35s. the cell cultures were derived from hairy roots obtained via genetically modified agrobacterium rhizogenes carrying the pri and plal21 plasmids. the cultures were fed with ... | 2007 | 16904229 |
| identification of genomic species in agrobacterium biovar 1 by aflp genomic markers. | biovar 1 of the genus agrobacterium consists of at least nine genomic species that have not yet received accepted species names. however, rapid identification of these organisms in various biotopes is needed to elucidate crown gall epidemiology, as well as agrobacterium ecology. for this purpose, the aflp methodology provides rapid and unambiguous determination of the genomic species status of agrobacteria, as confirmed by additional dna-dna hybridizations. the aflp method has been proven to be ... | 2006 | 16936063 |
| the rolc gene induces expression of a pathogenesis-related beta-1,3-glucanase in transformed ginseng cells. | the agrobacterium rhizogenes rolc oncogene is capable of stimulating production of secondary metabolites in transformed plant cells that suggest its possible involvement in plant defense reactions. we tested whether the gene could also affect production of pathogenesis-related proteins. using a well-known group of pr-proteins, such as beta-1,3-glucanases, we observed a 10-fold increase in total beta-1,3-glucanase activity in rolc-transformed panax ginseng cells compared with normal cells. the in ... | 2006 | 16950484 |
| genetic transformation of gentiana macrophylla with agrobacterium rhizogenes: growth and production of secoiridoid glucoside gentiopicroside in transformed hairy root cultures. | hairy root cultures of gentiana macrophylla were established by infecting the different explants four agrobacterium rhizogenes strains namely a(4)gus, r1000, lba 9402 and atcc11325, and hairy root lines were established with a. rhizogenes strain r1000 in 1/2 ms + b(5) medium. initially, 42 independent hairy root clones were maintained and seven clones belongs to different category were evaluated for growth, morphology, integration and expression of ri t-dna genes, and alkaloid contents in dry ro ... | 2007 | 16972092 |
| genetic transformation of echinacea purpurea with agrobacterium rhizogenes and bioactive ingredient analysis in transformed cultures. | a method of the transformed hairy roots cultures of echinacea purpurea was established by infecting different types of explants with three type strains of agrobacterium rhizogenes (a4, r1601 and r1000) in this paper. we obtained that the transformed percentage of e. purpurea leaves with a4, r1601 and r1000 were 80%, 60%, 40%, respectively and that of e. purpurea leafstalks were 10%, 30%, 45%, respectively. the contents of polysaccharides and phenolic compounds were measured in transformed hairy ... | 2006 | 16982176 |
| generation of composite plants using agrobacterium rhizogenes. | limitations in transformation capability can be a significant barrier in making advances in our understanding of gene function through the use of transgenics. to this end we have developed both tissue culture and non-tissue culture-based methodologies for the production of transgenic roots on wild-type shoots (composite plants). composite plants are generated by inoculating wild-type shoots with agrobacterium rhizogenes, which subsequently induces the formation of transgenic roots. the composite ... | 2006 | 16988342 |
| hairy roots induced by agrobacterium rhizogenes and production of regenerative plants in hairy root cultures in maize. | hairy roots of maize were induced by infecting 15-d calli with agrobacterium rhizogenes. the hairy roots cultured in hormone-free media showed the vigorous growth and typical hairy root features. the regenerated plants were produced from hairy roots in ms media supplemented with 1.6 mg/l zt and 0.4 mg/l naa. the pcr-southern hybridization demonstrated that t-dna had been integrated into the chromosome of regenerated plants. | 2006 | 16989275 |
| tropane alkaloids production in transgenic hyoscyamus niger hairy root cultures over-expressing putrescine n-methyltransferase is methyl jasmonate-dependent. | the cdna from nicotiana tabacum encoding putrescine n-methyltransferase (pmt), which catalyzes the first committed step in the biosynthesis of tropane alkaloids, has been introduced into the genome of a scopolamine-producing hyoscyamus niger mediated by the disarmed agrobacterium tumefaciens strain c58c1, which also carries agrobacterium rhizogenes ri plasmid pria4, and expressed under the control of the camv 35s promoter. hairy root lines transformed with pmt presented fivefold higher pmt activ ... | 2007 | 17004056 |