Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| isolation and characterization of mutants of thiophene synthesis in tagetes erecta. | two mutants of tagetes erecta displaying aberrant thiophene composition were identified by screening more than 300 plants from a mutagenized m2 population using high-performance liquid chromatography analysis of root extracts. both mutants, which may have originated from the same mutational event, contained high amounts of the c13 monothiophene 2-(but-3-en-1-ynyl)-5-(penta-1,3-diynyl)-thiophene that was previously not found in t. erecta and also high amounts of two c13 bithienyls that were absen ... | 1995 | 12228405 |
| 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 ... | 1993 | 12231827 |
| 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 ... | 1994 | 12232224 |
| 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 ... | 1994 | 12232401 |
| 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 ... | 2002 | 12236602 |
| 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 ... | 1994 | 12244219 |
| 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 ... | 2002 | 12368495 |
| expression profile analysis of the low-oxygen response in arabidopsis root cultures. | we used dna microarray technology to identify genes involved in the low-oxygen response of arabidopsis root cultures. a microarray containing 3500 cdna clones was screened with cdna samples taken at various times (0.5, 2, 4, and 20 h) after transfer to low-oxygen conditions. a package of statistical tools identified 210 differentially expressed genes over the four time points. principal component analysis showed the 0.5-h response to contain a substantially different set of genes from those regu ... | 2002 | 12368499 |
| a comparison of oligogalacturonide- and auxin-induced extracellular alkalinization and growth responses in roots of intact cucumber seedlings. | oligogalacturonic acid (oga) affects plant growth and development in an antagonistic manner to that of the auxin indole-3-acetic acid (iaa), the mechanism by which remains to be determined. this study describes the relationship between iaa and oga activity in intact cucumber (cucumis sativus) seedlings. both oga and iaa induced rapid and transient extracellular alkalinization; however, the characteristics of the oga and iaa responses differed in their kinetics, magnitude, calcium dependence, and ... | 2002 | 12376654 |
| endoplasmic microtubules configure the subapical cytoplasm and are required for fast growth of medicago truncatula root hairs. | to investigate the configuration and function of microtubules (mts) in tip-growing medicago truncatula root hairs, we used immunocytochemistry or in vivo decoration by a gfp linked to a mt-binding domain. the two approaches gave similar results and allowed the study of mts during hair development. cortical mts (cmts) are present in all developmental stages. during the transition from bulge to a tip-growing root hair, endoplasmic mts (emts) appear at the tip of the young hair and remain there unt ... | 2002 | 12376661 |
| 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 ... | 2002 | 12391546 |
| 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 ... | 2002 | 12391565 |
| 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 ... | 2002 | 12403830 |
| genomics and forest biology: populus emerges as the perennial favorite. | 2002 | 12417692 | |
| 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 ... | 2002 | 12423016 |
| 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 ... | 2001 | 12425082 |
| 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 ... | 2002 | 12426346 |
| 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 ... | 2002 | 12427275 |
| phosphorus effects on metabolic processes in monoxenic arbuscular mycorrhiza cultures. | the influence of external phosphorus (p) on carbon (c) allocation and metabolism as well as processes related to p metabolism was studied in monoxenic arbuscular mycorrhiza cultures of carrot (daucus carota). fungal hyphae of glomus intraradices proliferated from the solid minimal medium containing the colonized roots into c-free liquid minimal medium with different p treatments. the fungus formed around three times higher biomass in p-free liquid medium than in medium with 2.5 mm inorganic p (h ... | 2002 | 12427983 |
| 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 ... | 2002 | 12472692 |
| 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 ... | 2003 | 12511498 |
| 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. ... | 2003 | 12514038 |
| [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. | 2000 | 12516461 |
| [genetic transformation of autotetraploid isatis indigotica fort. induced by ri t-dna and plant regeneration]. | to establish an effective system for genetic transformation of autotetraploid isatis indigotica by agrobacterium rhizogenes. | 2000 | 12525069 |
| [genetic transformation of panax ginseng c.a. meyer induced by root inducing plasmid(ri) of agrobacterium rhizogenes]. | to obtain the hairy root of panax ginseng (hrpg). | 2001 | 12525104 |
| [transformation of sainfoin by agrobacterium rhizogenes lba9402 bin19 and regeneration of transgenic plants]. | hypocotyl segments of onobrychis viciaefolia were transformed by agrobacterium rhizogenes lba9402 which harboured pbin19 and pri1855. seedling age and preculture time of hypocotyl segments influenced the transformation frequency. paper electrophoresis revealed that 70% of single hairy root cultures could synthesize agropine. calli were induced from hairy root segments on ms medium containing 0-9.05 mumol/l 2,4-d and 0-2.22 mumol/l 6-ba at first, then they were transferred onto ms0 medium without ... | 2000 | 12548853 |
| [agrobacterium rhizogenes-mediated transformation and the regeneration of transformants in alhagi pseudalhagi]. | the regenerated shoot segments of alhagi pseudalhagi were sliced and infected with agrobacterium rhizogenes strain a4. the hairy roots and transformed calli were obtained through selection on hormone free ms medium. the transformants were cultured on ms medium with 2 mg/l 2,4-dichlorophenoxy acetic acid (2,4-d) and 0.5-1 mg/l 6-benzylaminopurine (6-ba) to induce calli. 3 mg/l 6-ba and 0.5 mg/l naphthalene acetic acid (naa) were applied for shoot differentiation. shoots were planted on ms medium ... | 2001 | 12549099 |
| auxin acts in xylem-associated or medullary cells to mediate apical dominance. | a role for auxin in the regulation of shoot branching was described originally in the thimann and skoog model, which proposes that apically derived auxin is transported basipetally directly into the axillary buds, where it inhibits their growth. subsequent observations in several species have shown that auxin does not enter axillary buds directly. we have found similar results in arabidopsis. grafting studies indicated that auxin acts in the aerial tissue; hence, the principal site of auxin acti ... | 2003 | 12566587 |
| identification of genetic factors controlling the efficiency of agrobacterium rhizogenes-mediated transformation in brassica oleracea by qtl analysis. | we have identified quantitative trait loci (qtl) for transgenic and adventitious root production using an agrobacterium rhizogenes-mediated co-transformation system in conjunction with a brassica oleracea double haploid (dh) mapping population. three qtl for green fluorescent protein (gfp)-fluorescent root production and four qtl for adventitious root production were identified as accounting for 26% and 32% of the genetic variation in the population, respectively. two of the qtl regions identifi ... | 2002 | 12582506 |
| potential for rhizofiltration of uranium using hairy root cultures of brassica juncea and chenopodium amaranticolor. | hairy root cultures of brassica juncea and chenopodium amaranticolor were developed by genetic transformation using agrobacterium rhizogenes. the stable, transformed root systems demonstrated a high growth rate of 1.5-3.0 g/g dry weight/day in murashige and skoog medium. in the present study, hairy root system was used for removal of uranium from the solution of concentration up to 5,000 microm. the results indicated that the hairy roots could remove uranium from the aqueous solution within a sh ... | 2003 | 12584014 |
| conjugative transfer of p42a from rhizobium etli cfn42, which is required for mobilization of the symbiotic plasmid, is regulated by quorum sensing. | rhizobium etli cfn42 contains six plasmids. only one of them, p42a, is self-conjugative at high frequency. this plasmid is strictly required for mobilization of the symbiotic plasmid (psym). to study the transfer mechanism of p42a, a self-transmissible cosmid clone containing its transfer region was isolated. its sequence showed that most of the tra genes are highly similar to genes of agrobacterium tumefaciens ptic58 and other related plasmids. four putative regulatory genes were identified; th ... | 2003 | 12591886 |
| evolutionary history, structural features and biochemical diversity of the nlpc/p60 superfamily of enzymes. | peptidoglycan is hydrolyzed by a diverse set of enzymes during bacterial growth, development and cell division. the n1pc/p60 proteins define a family of cell-wall peptidases that are widely represented in various bacterial lineages. currently characterized members are known to hydrolyze d-gamma-glutamyl-meso-diaminopimelate or n-acetylmuramate-l-alanine linkages. | 2003 | 12620121 |
| 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 ... | 2003 | 12644648 |
| 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 ... | 2003 | 12644677 |
| root factors induce mitochondrial-related gene expression and fungal respiration during the developmental switch from asymbiosis to presymbiosis in the arbuscular mycorrhizal fungus gigaspora rosea. | during spore germination, arbuscular mycorrhizal (am) fungi show limited hyphal development in the absence of a host plant (asymbiotic). in the presence of root exudates, they switch to a new developmental stage (presymbiotic) characterized by extensive hyphal branching. presymbiotic branching of the am fungus gigaspora rosea was induced in liquid medium by a semipurified exudate fraction from carrot (daucus carota) root organ cultures. changes in rna accumulation patterns were monitored by diff ... | 2003 | 12644696 |
| identification and characterization of a mandelamide hydrolase and an nad(p)+-dependent benzaldehyde dehydrogenase from pseudomonas putida atcc 12633. | the enzymes of the mandelate metabolic pathway permit pseudomonas putida atcc 12633 to utilize either or both enantiomers of mandelate as the sole carbon source. the genes encoding the mandelate pathway were found to lie on a single 10.5-kb restriction fragment. part of that fragment was shown to contain the genes coding for mandelate racemase, mandelate dehydrogenase, and benzoylformate decarboxylase arranged in an operon. here we report the sequencing of the remainder of the restriction fragme ... | 2003 | 12670968 |
| spatial and temporal analysis of the microbial community in slow sand filters used for treating horticultural irrigation water. | an experimental slow sand filter (ssf) was constructed to study the spatial and temporal structure of a bacterial community suppressive to an oomycete plant pathogen, phytophthora cryptogea. passage of water through the mature sand column resulted in complete removal of zoospores of the plant pathogen. to monitor global changes in the microbial community, bacterial and fungal numbers were estimated on selective media, direct viable counts of fungal spores were made, and the atp content was measu ... | 2003 | 12676691 |
| comparison of growth characteristics of panax ginseng hairy roots in various bioreactors. | this study investigated the effects of flask-to-liquid volume ratio on the growth of panax ginseng hairy root, transformed by agrobacterium rhizogenes, in flask cultures and compared the characteristics of various bioreactors for scale-up. the flask-to-liquid volume ratio was optimum at 1.5 ml of air/ml of medium in flask cultures, and hairy root growth was not affected above the optimum ratio. in 500-ml flask culture, hairy root showed two growth phases. after the first exponential growth, spec ... | 2003 | 12721430 |
| roses by other names: taxonomy of the rhizobiaceae. | 2003 | 12730155 | |
| discordant phylogenies within the rrn loci of rhizobia. | it is evident from complete genome sequencing results that lateral gene transfer and recombination are essential components in the evolutionary process of bacterial genomes. since this has important implications for bacterial systematics, the primary objective of this study was to compare estimated evolutionary relationships among a representative set of alpha-proteobacteria by sequencing analysis of three loci within their rrn operons. tree topologies generated with 16s rrna gene sequences were ... | 2003 | 12730157 |
| promoter of the rolc gene of agrobacterium rhizogenes can be strongly regulated in glandular cell of transgenic tobacco. | a 577-bp promoter segment of agrobacterium rhizogenes rolc, previously known as the phloem-specific gene expression promoter, was fused to the 5' end of a reporter gene, beta-glucuronidase (gus), uida. this rolc-promoter-driven expression of the gus gene was found to be significantly strong in glandular cells in transgenic tobacco plants. analysis of this segment of the promoter sequence revealed a myb response element. | 2003 | 12746553 |
| sporamin-mediated resistance to beet cyst nematodes (heterodera schachtii schm.) is dependent on trypsin inhibitory activity in sugar beet (beta vulgaris l.) hairy roots. | sporamin, a sweet potato tuberous storage protein, is a kunitz-type trypsin inhibitor. its capability of conferring insect-resistance on transgenic tobacco and cauliflower has been confirmed. to test its potential as an anti-feedant for the beet cyst nematode (heterodera schachtii schm.), the sporamin gene spti-1 was introduced into sugar beet (beta vulgaris l.) by agrobacterium rhizogenes-mediated transformation. twelve different hairy root clones expressing sporamin were selected for studying ... | 2003 | 12777044 |
| root formation from transgenic calli of ginkgo biloba. | the objective of this study was to produce ginkgo biloba l. hairy roots for future investigations into the feasibility of producing terpenoids in differentiated cell cultures. zygotic embryos of g. biloba were inoculated with the wild agropine-type agrobacterium rhizogenes strain a4. three months after bacterial infection, primordia-like nodular structures formed at the root wound sites and developed into tiny calli. calli cultivated on hormone-free lloyd and mccown (1980) solid medium were tran ... | 2003 | 12777244 |
| induction of parthenocarpy in tomato via specific expression of the rolb gene in the ovary. | the molecular signals for the development of the ovary into fruit following ovule fertilization are not clear. however, in many species, including tomato ( lycopersicon esculentum mill.), auxins and auxin transport inhibitors can substitute for fertilization as activators of fruit set, suggesting that this plant hormone plays a key role in this process. in agreement, transgenes for auxin biosynthesis expressed under ovary- or ovule-specific promoters were shown earlier to enable parthenocarpic ( ... | 2003 | 12783228 |
| production of an allelopathic polyacetylene in hairy root cultures of goldenrod (solidago altissima l.). | hairy roots of goldenrod (solidago altissima l.) were induced by infecting axenic plants with agrobacterium rhizogenes strain a4. growth and allelopathic polyacetylene (cis-dehydromatricaria ester, cis-dme) production of two independent hairy root clones were examined in several culture media and light regimes. cis-dme contents in hairy roots were at the same level as those in normal roots. cis-dme production in root cultures was several-fold lower than that of native plants and greatly represse ... | 2003 | 12784629 |
| rhizosecretion of recombinant proteins from plant hairy roots. | rhizosecretion of a target protein in the hydroponic medium provides an alternative manufacturing platform that simplifies the downstream purification procedure and increases protein yield. in order to increase the production rates of rhizosecreted proteins, we have exploited the ability of agrobacterium rhizogenes to induce the formation of large amounts of root tissue on transgenic tobacco plants engineered to secrete a model recombinant protein, human secreted alkaline phosphatase (seap). the ... | 2003 | 12819926 |
| 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 ... | 2003 | 12823862 |
| 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 ... | 2003 | 12830385 |
| horticultural characterization of angelonia salicariifolia plants transformed with wild-type strains of agrobacterium rhizogenes. | genetic transformation was carried out with wild-type strains of agrobacterium rhizogenes for introducing a dwarf trait into the scrophulariaceous ornamental plant, angelonia (angelonia salicariifolia). leaf segments of two angelonia genotypes (ang.1 and ang.2) were co-cultivated with mikimopine-type strains of a. rhizogenes. adventitious roots that showed vigorous growth and increased lateral branching when cultured on half-strength murashige and skoog's (ms) basal salts medium lacking plant gr ... | 2003 | 12835908 |
| genetic transformation of pueraria phaseoloides with agrobacterium rhizogenes and puerarin production in hairy roots. | an efficient transformation system for the medicinal plant pueraria phaseoloides was established by using agropine-type agrobacterium rhizogenes atcc15834. hairy roots could be obtained directly from the cut edges of petioles of leaf explants or via callus 10 days after inoculation with the bacteria. the highest frequency of explant transformation by a. rhizogenes atcc15834 was about 70% after infection for 30 days. hairy roots could grow rapidly on solid, growth regulator-free murashige and sko ... | 2003 | 12836005 |
| the balance of driving forces during genome evolution in prokaryotes. | genomes are shaped by evolutionary processes such as gene genesis, horizontal gene transfer (hgt), and gene loss. to quantify the relative contributions of these processes, we analyze the distribution of 12,762 protein families on a phylogenetic tree, derived from entire genomes of 41 bacteria and 10 archaea. we show that gene loss is the most important factor in shaping genome content, being up to three times more frequent than hgt, followed by gene genesis, which may contribute up to twice as ... | 2003 | 12840037 |
| fused rola protein enhances beta-glucoronidase activity 50-fold: implication for rola mechanism of action. | we report that the plant oncoprotein rola from agrobacterium rhizogenes acts to stabilize beta-glucoronidase (gus) when the two proteins are expressed as a fusion protein in transformed tobacco. the observed 50-fold increase of gus activity was shown to be related to protein accumulation, with no significant changes in mrna abundance, kinetic properties of the enzyme and thermostability. the entire rola sequence is essential to achieve the full effect since both the n-terminal region, spanning a ... | 2003 | 12871150 |
| development of linum flavum hairy root cultures for production of coniferin. | linum flavum hairy roots were initiated from leaf discs using agrobacterium rhizogenes strains lba9402 and tr105 though two other strains, 15834 and a4, were relatively ineffective for induction. significant variation in coniferin accumulation was observed between hairy root lines originating from different l. flavum seedlings and/or a. rhizogenes strains. coniferin reached 58 mg g-1 dry wt by culturing the roots in linsmaier and skoog (ls) medium with 2,4-dichlorophenoxyacetic acid and naphthal ... | 2003 | 12882138 |
| enhanced production of antimicrobial sesquiterpenes and lipoxygenase metabolites in elicitor-treated hairy root cultures of solanum tuberosum. | potato (solanum tuberosum) hairy root cultures, established by infecting potato tuber discs with agrobacterium rhizogenes, were used as a model system for the production of antimicrobial sesquiterpenes and lipoxygenase (lox) metabolites. of the four sesquiterpene phytoalexins (rishitin, lubimin, phytuberin and phytuberol) detected in elicitor-treated hairy root cultures, rishitin (213 micrograms g-1 dry wt) was the most predominant followed by lubimin (171 micrograms g-1 dry wt). the elicitors a ... | 2003 | 12882150 |
| production of ajmalicine and ajmaline in hairy root cultures of rauvolfia micrantha hook f., a rare and endemic medicinal plant. | hairy roots of rauvolfia micrantha were induced from hypocotyl explants of 2-3 weeks old aseptic seedlings using agrobacterium rhizogenes atcc 15834. hairy roots grown in half-strength murashige & skoog (ms) medium with 0.2 mg indole 3-butyric acid l-1 and 0.1 mg alpha-naphthaleneacetic acid l-1 produced more ajmaline (0.01 mg g-1 dry wt) and ajmalicine (0.006 mg g-1 dry wt) than roots grown in auxin-free medium. ajmaline (0.003 mg g-1 dry wt) and ajmalicine (0.0007 mg g-1 dry wt) were also prod ... | 2003 | 12882157 |
| genome structure of ri plasmid (3). sequencing analysis of the vir region of pri1724 in japanese agrobacterium rhizogenes. | the entire genome of the pri1724 (217.6-kb) in the mikimopine type agrobacterium rhizogenes strain maff03-01724 has been completely sequenced. the vir region covering 30.2-kb has found to be composed of 21 genes resembling virh1, vira, virb1-11, virg, virc1-2, and vird1-5. the structural organization of the pri1724 vir operons in this study is exactly the same as that of the previously reported vir operons of other ri or ti plasmids, although the size of some orfs showed little variations among ... | 2000 | 12903285 |
| gene silencing by expression of hairpin rna in lotus japonicus roots and root nodules. | we investigated the efficacy of self-complementary hairpin rna (hprna) expression to induce rna silencing in the roots and nodules of model legume lotus japonicus, using hairy root transformation mediated by agrobacterium rhizogenes. transgenic lines that express beta-glucuronidase (gus) by constitutive or nodule-specific promoters were supertransformed by infection of a. rhizogenes harboring constructs for the expression of hprnas with sequences complementary to the gus coding region. gus activ ... | 2003 | 12906110 |
| increase in anthraquinone content in rubia cordifolia cells transformed by rol genes does not involve activation of the nadph oxidase signaling pathway. | it has been reported that rol plant oncogenes located in ri-plasmids of agrobacterium rhizogenes activated synthesis of secondary metabolites in the transformed plant cells. the activator mechanism is still unknown. in this work, we studied whether the nadph oxidase-signaling pathway, which regulates the synthesis of defense metabolites in plants, is involved in the activator function of the rol genes. it was demonstrated that the transformation of rubia cordifolia cells by the rolb and rolc gen ... | 2003 | 12946262 |
| endoreduplication mediated by the anaphase-promoting complex activator ccs52a is required for symbiotic cell differentiation in medicago truncatula nodules. | in medicago nodules, endoreduplication cycles and ploidy-dependent cell enlargement occur during the differentiation of bacteroid-containing nitrogen-fixing symbiotic cells. these events are accompanied by the expression of ccs52a, a plant ortholog of the yeast and animal cdh1/srw1/fzr genes, acting as a substrate-specific activator of the anaphase-promoting complex (apc) ubiquitin ligase. because ccs52a is involved in the transition of mitotic cycles to endoreduplication cycles, we investigated ... | 2003 | 12953113 |
| transcript profiling coupled with spatial expression analyses reveals genes involved in distinct developmental stages of an arbuscular mycorrhizal symbiosis. | the formation of symbiotic associations with arbuscular mycorrhizal (am) fungi is a phenomenon common to the majority of vascular flowering plants. here, we used cdna arrays to examine transcript profiles in medicago truncatula roots during the development of an am symbiosis with glomus versiforme and during growth under differing phosphorus nutrient regimes. three percent of the genes examined showed significant changes in transcript levels during the development of the symbiosis. most genes sh ... | 2003 | 12953114 |
| effects of soil ph on the biodegradation of chlorpyrifos and isolation of a chlorpyrifos-degrading bacterium. | we examined the role of microorganisms in the degradation of the organophosphate insecticide chlorpyrifos in soils from the united kingdom and australia. the kinetics of degradation in five united kingdom soils varying in ph from 4.7 to 8.4 suggested that dissipation of chlorpyrifos was mediated by the cometabolic activities of the soil microorganisms. repeated application of chlorpyrifos to these soils did not result in the development of a microbial population with an enhanced ability to degra ... | 2003 | 12957902 |
| translation start sequences affect the efficiency of silencing of agrobacterium tumefaciens t-dna oncogenes. | agrobacterium tumefaciens oncogenes cause transformed plant cells to overproduce auxin and cytokinin. two oncogenes encode enzymes that convert tryptophan to indole-3-acetic acid (auxin): iaam (tryptophan mono-oxygenase) and iaah (indole-3-acetamide hydrolase). a third oncogene (ipt) encodes amp isopentenyl transferase, which produces cytokinin (isopentenyl-amp). inactivation of ipt and iaam (or iaah) abolishes tumorigenesis. because adequate means do not exist to control crown gall, we created ... | 2003 | 12972655 |
| camptothecin and 10-hydroxycamptothecin from camptotheca acuminata hairy roots. | camptothecin (cpt) is an anticancer and antiviral alkaloid produced by the chinese tree camptotheca acuminata (nyssaceae) and some other species belonging to the families apocynaceae, olacaceae, and rubiaceae. bark and seeds are currently used as sources for the drug. several attempts have been made to produce cpt from cell suspensions; however, the low yields obtained limit this approach. cultures of differentiated cell types may be an alternative source of alkaloid production. hairy root cultu ... | 2004 | 13680137 |
| effect of chitosan on peroxidase activity and isoenzyme profile in hairy root cultures of armoracia lapathifolia. | hairy root cultures of armoracia lapathifolia established by infection with agrobacterium rhizogenes lba 9402 present a level and isoenzyme pattern of peroxidases (pod) comparable to nontransformed roots. elicitation with chitosan (10, 50, and 100 mg/l) was used in order to improve pod production. total pod activity increased about 170% after 48 h of treatment with chitosan 100 mg/l. elicitation effect on soluble and ionically cell-wall-bound pod fractions of a. lapathifolia hairy roots was anal ... | 2003 | 14512637 |
| effects of ca(2+) channel blockers and protein kinase/phosphatase inhibitors on growth and anthraquinone production in rubia cordifolia callus cultures transformed by the rolb and rolc genes. | the transformation of rubia cordifolia l. cells by the 35s- rolb and 35s- rolc genes of agrobacterium rhizogenes caused a growth inhibition of the resulting cultures and an induction of the biosynthesis of anthraquinone-type phytoalexins. inhibitor studies revealed a striking difference between the rolc- and rolb-gene-transformed cultures in their sensitivity to verapamil, an l-type ca(2+) channel blocker. the rolc culture possessed a 2-fold lowered resistance to the inhibitor than the normal cu ... | 2003 | 14520561 |
| physical and gene maps of agrobacterium biovar 2 strains and their relationship to biovar 1 chromosomes. | diverse types of genomic dna organization have been found in rhizobiaceae, especially among agrobacterium species. previous studies of agrobacterium concentrated mainly on biovar 1 strains. little attention has been given to biovar 2 strains. the biovar 2 genome consists of a large, circular chromosome and second megabase-sized replicon, as well as several plasmids. in this study two biovar 2 strains were analysed, a. rhizogenes (a. radiobacter) k84 and a. rhizogenes a4, by constructing physical ... | 2003 | 14523134 |
| transgenic hairy roots. recent trends and applications. | agrobacterium rhizogenes causes hairy root disease in plants. the neoplastic roots produced by a. rhizogenes infection is characterized by high growth rate and genetic stability. these genetically transformed root cultures can produce higher levels of secondary metabolites or amounts comparable to that of intact plants. hairy root cultures offer promise for production of valuable secondary metabolites in many plants. the main constraint for commercial exploitation of hairy root cultures is their ... | 2000 | 14538116 |
| characterization of four lectin-like receptor kinases expressed in roots of medicago truncatula. structure, location, regulation of expression, and potential role in the symbiosis with sinorhizobium meliloti. | to study the role of lecrk (lectin-like receptor kinase) genes in the legumerhizobia symbiosis, we have characterized the four medicago truncatula gaernt. lecrk genes that are most highly expressed in roots. three of these genes, mtlecrk7;1, mtlecrk7;2, and mtlecrk7;3, encode proteins most closely related to the class a lecrks of arabidopsis, whereas the protein encoded by the fourth gene, mtlecrk1;1, is most similar to a class b arabidopsis lecrk. all four genes show a strongly enhanced root ex ... | 2003 | 14630957 |
| new connections in the prokaryotic toxin-antitoxin network: relationship with the eukaryotic nonsense-mediated rna decay system. | several prokaryotic plasmids maintain themselves in their hosts by means of diverse post-segregational cell killing systems. recent findings suggest that chromosomally encoded copies of toxins and antitoxins of post-segregational cell killing systems - such as the rele system - might function as regulatory switches under stress conditions. the rele toxin cleaves ribosome-associated transcripts, whereas another post-segregational cell killing toxin, pare, functions as a gyrase inhibitor. | 2003 | 14659018 |
| role of soil ph in the development of enhanced biodegradation of fenamiphos. | repeated treatment with fenamiphos (ethyl 4-methylthio-m-tolyl isopropylphosphoramidate) resulted in enhanced biodegradation of this nematicide in two united kingdom soils with a high ph (>/= 7.7). in contrast, degradation of fenamiphos was slow in three acidic united kingdom soils (ph 4.7 to 6.7), and repeated treatments did not result in enhanced biodegradation. rapid degradation of fenamiphos was observed in two australian soils (ph 6.7 to 6.8) in which it was no longer biologically active ag ... | 2003 | 14660347 |
| [culture of hairy roots in pueraria phaseoloides and its puerarin production]. | an efficient transformation system for genetic transformation of medicinal plant, pueraria phaseoloides was developed, by using agropine-type agrobacterium rhizogenes atcc15834. hairy roots could be obtained via callus from the cut edges of leaf explants of p. phaseoloides 20 days after inoculation with agrobacterium. 35 days after infection, the percentage of rooted leaf explants was about 85%. hairy roots could have an autonomous growth on solid or liquid growth regulator-free ms medium but gr ... | 2003 | 14724930 |
| penicillin derivatives induce chemical structure-dependent root development, and application for plant transformation. | we investigated five penicillin derivatives that are popularly used for transformation experiments with agrobacterium rhizogenes-penicillin g, carbenicillin, ampicillin, amoxicillin and cephalexin-for their effects on the growth and morphology of beta vulgaris, capsicum annuum and glehnia littoralis roots. attention was given to the relationship between their chemical structures and functions. ampicillin was found to stimulate root elongation but inhibit root branching, whereas carbenicillin inh ... | 2004 | 14727052 |
| transformation of ipecac (cephaelis ipecacuanha) with agrobacterium rhizogenes. | transformed root cultures of ipecac (cephaelis ipecacuanha a. richard), one of the recalcitrant woody plant species for agrobacterium-mediated transformation, were established by co-culturing of in vitro petiole segments with agrobacterium rhizogenes atcc 15 834. southern blot analysis of the established roots revealed that only the tl-dna was integrated into the plant genome without incorporation of the tr-dna. the transformed roots grew slowly on phytohormone-free solid medium and adventitious ... | 2003 | 14735440 |
| hairy root induction of papaver somniferum var. album, a difficult-to-transform plant, by a rhizogenes lba 9402. | two strains of agrobacterium rhizogenes (15834, lba 9402) and one agrobacterium tumefaciens strain [gv 3101 (pmp90rk, p35sgus-2)] and four culture media were tested and compared for their ability to induce hairy root formation on wounded papaver somniferum l. hypocotyls. five weeks after the infection with a. rhizogenes lba 9402, hairy roots appeared on 80% of the hypocotyls maintained in the hormone-free liquid medium. six hairy-root cultures were established. transformation was confirmed by po ... | 2004 | 14740216 |
| agrobacterium rhizogenes-mediated dna transfer to aesculus hippocastanum l. and the regeneration of transformed plants. | hairy roots were induced from androgenic embryos of horse chestnut (aesculus hippocastanum l.) by infection with agrobacterium rhizogenes strain a4gus. single roots were selected according to their morphology in the absence of antibiotic or herbicide resistance markers. seventy-one putative transformed hairy root lines from independent transformation events were established. regeneration was induced in ms liquid medium supplemented with 30 microm 6-benzylaminopurine (ba), and the regenerants wer ... | 2004 | 14745503 |
| a quick and efficient system for antibiotic-free expression of heterologous genes in tobacco roots. | requirement for antibiotic-resistance selection markers and difficulty in identifying transgenes with the highest expression levels remain the major obstacles for rapid production of recombinant proteins in plants. an alternative approach to producing transgenic plants free of antibiotic-resistance markers is the phenotypic-based selection with root-proliferation genes (rol genes) of agrobacterium rhizogenes. by using agrobacterium tumefaciens harboring the pryg transformation vector with a clus ... | 2004 | 14770265 |
| plant regeneration from hairy-root cultures transformed by infection with agrobacterium rhizogenes in catharanthus roseus. | hypocotyl explants of catharanthus roseus produced hairy roots when cultured on murashige and skoog (ms) basal medium after infection by agrobacterium rhizogenes. explants gave rise to adventitious shoots at a frequency of up to 80% when cultured on ms medium supplemented with 31.1 microm 6-benzyladenine and 5.4 microm alpha-naphthaleneacetic acid. there was a significant difference in the frequency of adventitious shoot formation for each hairy-root line derived from a different cultivar. plant ... | 2004 | 14963692 |
| agrobacterium rhizogenes-mediated transformation to improve rooting ability of eucalypts. | in an attempt to improve rooting in in vitro propagated eucalyptus clones, root-inducing genes on the ri plasmids of three agrobacterium rhizogenes strains were inserted into the eucalyptus genome. root development was monitored in vitro and after the plantlets had hardened off. only transformed roots grew as root cultures in hormone-free liquid medium. the potential use of this procedure for improving rooting of clonal material is discussed. | 1993 | 14969911 |
| agrobacterium rhizogenes-mediated transformation of taraxacum platycarpum and changes of morphological characters. | transformed hairy roots were efficiently induced from seedlings of taraxacum platycarpum by infection with agrobacterium rhizogenes 15834. root explants produced transformed roots at a higher frequency (76.5+/-3.5%) as compared to stem (32.7+/-4.8%) or cotyledon (16.2+/-5.7%). hairy roots exhibited active elongation with high branching of roots on growth regulator-free medium. the competence of plant regeneration from non-transformed adventitious roots and transformed hairy roots was compared. t ... | 2004 | 14986056 |
| agrobacterium rhizogenes vs auxinic induction for in vitro rhizogenesis of prosopis chilensis and nothofagus alpina. | the induction and improvement of in vitro rhizogenesis of microshoots of prosopis chilensis (mol.) stuntz and nothofagus alpina (poep. et endl. oerst.) were compared using agrobacterium rhizogenes (ar) versus indole-3-butyric acid (iba) in the culture media. microshoots of p. chilensis (1-2 cm length), coming from in vitro grown seedlings, were cultivated in a modified broadleaved tree medium (btmm) containing half salt concentration of macronutrients and 0.05 mg x l(-1) benzilaminopurine (bap). ... | 2003 | 15002748 |
| enod40, a short open reading frame-containing mrna, induces cytoplasmic localization of a nuclear rna binding protein in medicago truncatula. | in eukaryotes, diverse mrnas containing only short open reading frames (sorf-mrnas) are induced at specific stages of development. their mechanisms of action may involve the rna itself and/or sorf-encoded oligopeptides. enod40 genes code for highly structured plant sorf-mrnas involved in root nodule organogenesis. a novel rna binding protein interacting with the enod40 rna, mtrbp1 (for medicago truncatula rna binding protein 1), was identified using a yeast three-hybrid screening. immunolocaliza ... | 2004 | 15037734 |
| identification of the bacterial community of maple sap by using amplified ribosomal dna (rdna) restriction analysis and rdna sequencing. | the bacterial community of maple sap was characterized by analysis of samples obtained at the taphole of maple trees for the 2001 and 2002 seasons. among the 190 bacterial isolates, 32 groups were formed according to the similarity of the banding patterns obtained by amplified ribosomal dna restriction analysis (ardra). a subset of representative isolates for each ardra group was identified by 16s rrna gene fragment sequencing. results showed a wide variety of organisms, with 22 different genera ... | 2004 | 15066796 |
| rna interference in agrobacterium rhizogenes-transformed roots of arabidopsis and medicago truncatula. | rna interference (rnai) is a powerful reverse genetic tool to study gene function. the data presented here show that agrobacterium rhizogenes-mediated rnai is a fast and effective tool to study genes involved in root biology. the arabidopsis gene kojak, involved in root hair development, was efficiently knocked down. a. rhizogenes-mediated root transformation is a fast method to generate adventitious, genetically transformed roots. in order to select for co-transformed roots a binary vector was ... | 2004 | 15073217 |
| evolutionary conservation of a phosphate transporter in the arbuscular mycorrhizal symbiosis. | arbuscular mycorrhizae are ancient symbioses that are thought to have originated >400 million years ago in the roots of plants, pioneering the colonization of terrestrial habitats. in these associations, a key process is the transfer of phosphorus as inorganic phosphate to the host plant across the fungus-plant interface. mycorrhiza-specific phosphate transporter genes and their regulation are conserved in phylogenetically distant plant species, and they are activated selectively by fungal speci ... | 2004 | 15075387 |
| characterization of three functional high-affinity ammonium transporters in lotus japonicus with differential transcriptional regulation and spatial expression. | ammonium is a primary source of nitrogen for plants. in legume plants ammonium can also be obtained by symbiotic nitrogen fixation, and nh(4)(+) is also a regulator of early and late symbiotic interaction steps. ammonium transporters are likely to play important roles in the control of nodule formation as well as in nitrogen assimilation. two new genes, ljamt1;2 and ljamt1;3, were cloned from lotus japonicus. both were able to complement the growth defect of a yeast (saccharomyces cerevisiae) am ... | 2004 | 15075393 |
| nuclear localization and interaction of rolb with plant 14-3-3 proteins correlates with induction of adventitious roots by the oncogene rolb. | the rooting-locus gene b (rolb) on the t-dna of the root-inducing (ri) plasmid in agrobacterium rhizogenes is responsible for the induction of transformed adventitious roots, although the root induction mechanism is unknown. we report here that the rolb protein of pri1724 (1724rolb) is associated with nicotianatabacum14-3-3-like protein omegaii (nt14-3-3 omegaii) in tobacco bright yellow (by)-2 cells. nt14-3-3 omegaii directly interacts with 1724rolb protein. green fluorescent protein (gfp)-fuse ... | 2004 | 15078329 |
| engineering tropane biosynthetic pathway in hyoscyamus niger hairy root cultures. | scopolamine is a pharmaceutically important tropane alkaloid extensively used as an anticholinergic agent. here, we report the simultaneous introduction and overexpression of genes encoding the rate-limiting upstream enzyme putrescine n-methyltransferase (pmt) and the downstream enzyme hyoscyamine 6 beta-hydroxylase (h6h) of scopolamine biosynthesis in transgenic henbane (hyoscyamus niger) hairy root cultures. transgenic hairy root lines expressing both pmt and h6h produced significantly higher ... | 2004 | 15084741 |
| t-dna and transposon tagging in aspen. | we have investigated the somatic activity of the maize activator (ac) element in haploid and diploid aspen with the objective of developing an efficient transposon-based system for gene isolation in the model tree species populus. it was shown that ac is reinserted, frequently into or near coding regions in aspen, and therefore can be used for gene tagging studies. a number of phenotypic variants were also found following transformation of constructs harbouring the rolc gene. comparative analyse ... | 2004 | 15095129 |
| agrobacterium rhizogenes galls protein substitutes for agrobacterium tumefaciens single-stranded dna-binding protein vire2. | agrobacterium tumefaciens and agrobacterium rhizogenes transfer plasmid-encoded genes and virulence (vir) proteins into plant cells. the transferred dna (t-dna) is stably inherited and expressed in plant cells, causing crown gall or hairy root disease. dna transfer from a. tumefaciens into plant cells resembles plasmid conjugation; single-stranded dna (ssdna) is exported from the bacteria via a type iv secretion system comprised of virb1 through virb11 and vird4. bacteria also secrete certain vi ... | 2004 | 15126468 |
| acquisition of an agrobacterium ri plasmid and pathogenicity by other alpha-proteobacteria in cucumber and tomato crops affected by root mat. | root mat of cucumbers and tomatoes has previously been shown to be caused by agrobacterium radiobacter strains harboring a root-inducing ri plasmid (pri). nine other pri-harboring alpha-proteobacteria have subsequently been isolated from root mat-infected crops. fatty acid profiling and partial 16s rrna sequence analysis identified three of these strains as being in the genus ochrobactrum, five as being in the genus rhizobium, and one as being in the genus sinorhizobium: an in vitro pathogenicit ... | 2004 | 15128532 |
| auxins affected ginsenoside production and growth of hairy roots in panax hybrid. | hairy roots of interspecific hybrid ginseng (panax ginseng x p. quinquefolium), induced by agrobacterium rhizogenes atcc 15834, grew well in b5 liquid media supplemented with 2.5 microm auxins (3-indole butyric acid (iba), 1-naphtaleneacetic acid (naa) and 3-indoleacetic acid (iaa)). the hairy roots cultured in b5 liquid medium supplemented with 2.5 microm iba showed best growth (6.39 g fresh weight per a flask, at week 8). the highest content of the total ginsenosides was 1.63% as dry weight at ... | 2004 | 15133240 |
| proton-transfer-reaction mass spectrometry as a new tool for real time analysis of root-secreted volatile organic compounds in arabidopsis. | plant roots release about 5% to 20% of all photosynthetically-fixed carbon, and as a result create a carbon-rich environment for numerous rhizosphere organisms, including plant pathogens and symbiotic microbes. although some characterization of root exudates has been achieved, especially of secondary metabolites and proteins, much less is known about volatile organic compounds (vocs) released by roots. in this communication, we describe a novel approach to exploring these rhizosphere vocs and th ... | 2004 | 15141066 |
| dynamic interactions between 14-3-3 proteins and phosphoproteins regulate diverse cellular processes. | 14-3-3 proteins exert an extraordinarily widespread influence on cellular processes in all eukaryotes. they operate by binding to specific phosphorylated sites on diverse target proteins, thereby forcing conformational changes or influencing interactions between their targets and other molecules. in these ways, 14-3-3s 'finish the job' when phosphorylation alone lacks the power to drive changes in the activities of intracellular proteins. by interacting dynamically with phosphorylated proteins, ... | 2004 | 15167810 |
| use of the tobacco feedback-insensitive anthranilate synthase gene (asa2) as a selectable marker for legume hairy root transformation. | the feedback-insensitive anthranilate synthase ( asa2) cdna--isolated from a 5-methyltryptophan (5mt)-resistant tobacco cell line--driven by the camv 35s promoter or 606 bp of the native asa2 promoter, was introduced into the forage legume plant astragalus sinicus or soybean ( glycine max), using agrobacterium rhizogenes strains dc-ar2 or k599, respectively. hairy roots of a. sinicus transformed with 35s-asa2 but not 606- asa2 could be directly selected using 20-75 micro m 5mt. asa2 mrna was exp ... | 2004 | 15168071 |
| solasodine glycoside production by hairy root cultures of physalis minima linn. | hairy root cultures of physalis minima l. were developed using agrobacterium rhizogenes, strain atcc 15834 mediated transformation and grown in half strength of murashige and skoog medium containing 8% (w/v) sucrose. media supplementation with 1 mg naphthalenacetic acid l(-1) and 1 mg benzyladenine increased solasodine glycoside up to 900 g dry wt, which was 20 times higher than that in the native root. | 2004 | 15168852 |
| replicase mediated resistance against potato leafroll virus in potato desirée plants. | potato leafroll virus (plrv) is a major menace for the potato production all over the world. plrv is transmitted by aphids, and until now, the only strategy available to control this pest has been to use large amounts of insecticides. transgenic approaches involving the expression of viral replicases are being developed to provide protection for plants against viral diseases. the purpose of this study was to compare the protection afforded by the differential expression of plrv replicate transge ... | 2004 | 15174307 |
| scale-up production of puerarin from hairy roots of pueraria phaseoloides in an airlift bioreactor. | hairy roots of the chinese herb, pueraria phaseoloides, obtained from leaf explants and transformed with the agrobacterium rhizogenes, were cultured in 2.5 l airlift bioreactors for three weeks. puerarin accumulated at 5,570 microg g(-1) dry wt, which is near 200 times as much as in 250 ml flask cultures. in addition, puearin was exuded into the nutrient medium at final concentrations higher than in the hairy roots themselves. | 2004 | 15218379 |
| growth and terpenoid indole alkaloid production in catharanthus roseus hairy root clones in relation to left- and right-termini-linked ri t-dna gene integration. | hairy root cultures of catharanthus roseus var. prabal were established by infecting the leaves with agrobacterium rhizogenes agropine-type a4 strain. two hundred and fifty independent root clones were evaluated for growth, morphology, number of integration of ri t-dna genes and alkaloid contents. on the basis of growth pattern, type of branching and number of lateral roots we were able to separate the hairy root clones into four categories. however based on the integration of the ri t(l)-dna an ... | 2004 | 15221274 |
| introduction of plant and fungal genes into pea (pisum sativum l.) hairy roots reduces their ability to produce pisatin and affects their response to a fungal pathogen. | pisatin is an isoflavonoid phytoalexin synthesized by pea (pisum sativum l.). previous studies have identified two enzymes apparently involved in the synthesis of this phytoalexin, isoflavone reductase (ifr), which catalyzes an intermediate step in pisatin biosynthesis, and (+)6a-hydroxymaackiain 3-o-methyltransferase (hmm), an enzyme catalyzing the terminal step. to further evaluate the involvement of these enzymes in pisatin biosynthesis, sense- and antisense-oriented cdnas of ifr and hmm fuse ... | 2004 | 15242174 |
| the orf13 t-dna gene of agrobacterium rhizogenes confers meristematic competence to differentiated cells. | plant infections by the soil bacterium agrobacterium rhizogenes result in neoplastic disease with the formation of hairy roots at the site of infection. expression of a set of oncogenes residing on the stably integrated t-dna is responsible for the disease symptoms. besides the rol (root locus) genes, which are essential for the formation of hairy roots, the open reading frame orf13 mediates cytokinin-like effects, suggesting an interaction with hormone signaling pathways. here we show that orf1 ... | 2004 | 15247407 |