Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| crown gall disease and prospects for genetic manipulation of plants. | agrobacterium tumefaciens incites crown gall tumors when bacterial dna integrates into plant nuclear dna. plant cells can express these integrated bacterial genes. following insertion of desired genes into bacterial dna using recombinant dna techniques, this system permits introduction of these new genes into plant dna. we discuss the potential for genetic manipulation of plants using agrobacterium tumefaciens and the related organism agrobacterium rhizogenes. | 1982 | 17807126 |
| lysm domains mediate lipochitin-oligosaccharide recognition and nfr genes extend the symbiotic host range. | legume-rhizobium symbiosis is an example of selective cell recognition controlled by host/non-host determinants. individual bacterial strains have a distinct host range enabling nodulation of a limited set of legume species and vice versa. we show here that expression of lotus japonicus nfr1 and nfr5 nod-factor receptor genes in medicago truncatula and l. filicaulis, extends their host range to include bacterial strains, mesorhizobium loti or dzl, normally infecting l. japonicus. as a result, th ... | 2007 | 17690687 |
| metabolic engineering of novel ketocarotenoid production in carrot plants. | carotenoids constitute a vast group of pigments that are ubiquitous throughout nature. carrot (daucus carota l.) roots provide an important source of dietary beta-carotene (provitamin a), alpha-carotene and lutein. ketocarotenoids, such as canthaxanthin and astaxanthin, are produced by some algae and cyanobacteria but are rare in plants. ketocarotenoids are strong antioxidants that are chemically synthesized and used as dietary supplements and pigments in the aquaculture and neutraceutical indus ... | 2008 | 17682834 |
| fast, efficient and reproducible genetic transformation of phaseolus spp. by agrobacterium rhizogenes. | this transformation procedure generates, with high efficiency (70-90%), hairy roots in cultivars, landraces and accessions of phaseolus vulgaris (common bean) and other phaseolus spp. hairy roots rapidly develop after wounding young plantlets with agrobacterium rhizogenes, at the cotyledon node, and keeping the plants in high-humidity conditions. callogenesis always precedes hairy-root formation, and after 15 days, when roots develop at wounded sites, the stem with the normal root is cleaved bel ... | 2007 | 17641650 |
| transcriptome profiling of lotus japonicus roots during arbuscular mycorrhiza development and comparison with that of nodulation. | to better understand the molecular responses of plants to arbuscular mycorrhizal (am) fungi, we analyzed the differential gene expression patterns of lotus japonicus, a model legume, with the aid of a large-scale cdna macroarray. experiments were carried out considering the effects of contaminating microorganisms in the soil inoculants. when the colonization by am fungi, i.e. glomus mosseae and gigaspora margarita, was well established, four cysteine protease genes were induced. in situ hybridiz ... | 2007 | 17634281 |
| enhanced production of asiaticoside from hairy root cultures of centella asiatica (l.) urban elicited by methyl jasmonate. | transformed root ("hairy root") cultures have been shown to be a good model for the study of many secondary metabolites. however, economically important compounds such as asiaticoside and madecassoside are produced in insignificant amounts in the root of centella asiatica (l.) urban. to overcome this problem, c. asiatica was transformed using agrobacterium rhizogenes strain r1000 that harbors pcambia1302 encoding the hygromycin phosphotransferase (hpt) and green fluorescence protein (mgfp5) gene ... | 2007 | 17632725 |
| the medicago truncatula dmi1 protein modulates cytosolic calcium signaling. | in addition to establishing symbiotic relationships with arbuscular mycorrhizal fungi, legumes also enter into a nitrogen-fixing symbiosis with rhizobial bacteria that results in the formation of root nodules. several genes involved in the development of both arbuscular mycorrhiza and legume nodulation have been cloned in model legumes. among them, medicago truncatula dmi1 (doesn't make infections1) is required for the generation of nucleus-associated calcium spikes in response to the rhizobial ... | 2007 | 17631529 |
| a generalized method for transfecting root epidermis uncovers endosomal dynamics in arabidopsis root hairs. | progress in analysing the cellular functions of many structural proteins has accelerated through the use of confocal microscopy together with transient gene expression. several methods for transient expression have been developed in the past few years, but their application has seen limited success beyond a few tractable species and tissues. we have developed a simple and efficient method to visualize fluorescent proteins in arabidopsis root epidermis using co-cultivation of seedlings with agrob ... | 2007 | 17610544 |
| medicago lyk3, an entry receptor in rhizobial nodulation factor signaling. | rhizobia secrete nodulation (nod) factors, which set in motion the formation of nitrogen-fixing root nodules on legume host plants. nod factors induce several cellular responses in root hair cells within minutes, but also are essential for the formation of infection threads by which rhizobia enter the root. based on studies using bacterial mutants, a two-receptor model was proposed, a signaling receptor that induces early responses with low requirements toward nod factor structure and an entry r ... | 2007 | 17586690 |
| translocation in legumes: assimilates, nutrients, and signaling molecules. | 2007 | 17556518 | |
| growth and rutin production in hairy root cultures of buckwheat (fagopyrum esculentum m.). | buckwheat (fagopyrum esculentum moench.) is a potentially important source of rutin, a natural flavonoid with antihyperglycemic, antihypertensive, and antioxidative properties. to examine in vitro production of rutin, we established a hairy root culture of buckwheat by infecting leaf explants with agrobacterium rhizogenes r1000, and tested the growth conditions and rutin production rates of these cultures. ten hairy root clones were established; their growth and rutin production rates ranged fro ... | 2007 | 17516253 |
| high efficiency agrobacterium rhizogenes-mediated transformation of saponaria vaccaria l. (caryophyllaceae) using fluorescence selection. | a highly efficient and convenient method for the agrobacterium rhizogenes-dependent production of transformed roots of saponaria vaccaria l. (caryophyllaceae) is described. the parameters tested and optimized include s. vaccaria cultivar, explant type, agrobacterium rhizogenes strain and culture conditions. for cotransformation using additional recombinant t-dna-containing a. rhizogenes strains, use of neomycin phosphotransferase and enhanced green fluorescent protein genes as selectable markers ... | 2007 | 17516073 |
| high efficiency poplar transformation. | with the completion of the poplar tree genome database, populus species have become one of the most useful model systems for the study of woody plant biology. populus tremuloides (quaking aspen) is the most wide-spread tree species in north america, and its rapid growth generates the most abundant wood-based biomass out of any other plant species. to study such beneficial traits, there is a need for easier and more efficient transformation procedures that will allow the study of large numbers of ... | 2007 | 17492451 |
| intron splicing in 5' untranslated region of the rola transcript in transgenic apple. | the rola gene encoded on the ri plasmid of agrobacterium rhizogenes causes developmental alterations, including dwarfing characteristics in the transgenic plants. in an attempt to introduce dwarfing characteristics into apple rootstocks for breeding purposes, the rola gene was incorporated into the apple rootstock m26 and obtained four transgenic clones. all the clones exhibited reduced growth compared to untransformed control plants but different degree of dwarfing and wrinkled leaves. in the p ... | 2008 | 17490782 |
| auxin and nitric oxide control indeterminate nodule formation. | rhizobia symbionts elicit root nodule formation in leguminous plants. nodule development requires local accumulation of auxin. both plants and rhizobia synthesise auxin. we have addressed the effects of bacterial auxin (iaa) on nodulation by using sinorhizobium meliloti and rhizobium leguminosarum bacteria genetically engineered for increased auxin synthesis. | 2007 | 17488509 |
| transcriptome analysis of arbuscular mycorrhizal roots during development of the prepenetration apparatus. | information on changes in the plant transcriptome during early interaction with arbuscular mycorrhizal (am) fungi is still limited since infections are usually not synchronized and plant markers for early stages of colonization are not yet available. a prepenetration apparatus (ppa), organized in epidermal cells during appressorium development, has been reported to be responsible for assembling a trans-cellular tunnel to accommodate the invading fungus. here, we used ppas as markers for cell res ... | 2007 | 17468219 |
| overlap of proteome changes in medicago truncatula in response to auxin and sinorhizobium meliloti. | we used proteome analysis to identify proteins induced during nodule initiation and in response to auxin in medicago truncatula. from previous experiments, which found a positive correlation between auxin levels and nodule numbers in the m. truncatula supernodulation mutant sunn (supernumerary nodules), we hypothesized (1) that auxin mediates protein changes during nodulation and (2) that auxin responses might differ between the wild type and the supernodulating sunn mutant during nodule initiat ... | 2007 | 17468210 |
| [effects of methyl jasmonat on accumulation and release of tanshinones in suspension cultures of salvia miltiorrhiza hairy root]. | to study the effects of methyl jasmonate (mj) on the accumulation and release of tanshinones in suspension cultures of salvia miltiorrhiza hairy roots. | 2007 | 17455461 |
| resistance to root-knot nematode in tomato roots expressing a nematicidal bacillus thuringiensis crystal protein. | our laboratory has demonstrated previously that bacillus thuringiensis (bt) crystal (cry) proteins present in the cry5 and cry6 subclades intoxicate free-living nematodes. in this study, we tested whether the expression of nematicidal cry6a in transgenic plants provided protection against plant-parasitic nematodes. as bacterial codon usage is incompatible with expression in plants, two different codon-modified cry6a genes were synthesized for expression in plants. one was designed by maintaining ... | 2007 | 17451491 |
| an erf transcription factor in medicago truncatula that is essential for nod factor signal transduction. | rhizobial bacteria activate the formation of nodules on the appropriate host legume plant, and this requires the bacterial signaling molecule nod factor. perception of nod factor in the plant leads to the activation of a number of rhizobial-induced genes. putative transcriptional regulators in the gras family are known to function in nod factor signaling, but these proteins have not been shown to be capable of direct dna binding. here, we identify an erf transcription factor, erf required for no ... | 2007 | 17449807 |
| agrobacterium rhizogenes-mediated transformation of soybean to study root biology. | this protocol is used to induce transgenic roots on soybean to study the function of genes required in biological processes of the root. young seedlings with unfolded cotyledons are infected at the cotyledonary node and/or hypocotyl with agrobacterium rhizogenes carrying the gene construct to be tested and the infection sites are kept in an environment of high humidity. when the emerged hairy roots can support the plants, the main roots are removed and the transgenic roots can be tested. using t ... | 2007 | 17446894 |
| flavone synthases from medicago truncatula are flavanone-2-hydroxylases and are important for nodulation. | flavones are important copigments found in the flowers of many higher plants and play a variety of roles in plant adaptation to stress. in medicago species, flavones also act as signal molecules during symbiotic interaction with the diazotropic bacterium sinorhizobium meliloti. they are the most potent nod gene inducers found in root exudates. however, flavone synthase ii (fns ii), the key enzyme responsible for flavone biosynthesis, has not been characterized in medicago species. we cloned two ... | 2007 | 17434990 |
| regulation of arbuscular mycorrhization by carbon. the symbiotic interaction cannot be improved by increased carbon availability accomplished by root-specifically enhanced invertase activity. | the mutualistic interaction in arbuscular mycorrhiza (am) is characterized by an exchange of mineral nutrients and carbon. the major benefit of am, which is the supply of phosphate to the plant, and the stimulation of mycorrhization by low phosphate fertilization has been well studied. however, less is known about the regulatory function of carbon availability on am formation. here the effect of enhanced levels of hexoses in the root, the main form of carbohydrate used by the fungus, on am forma ... | 2007 | 17416641 |
| rnai silencing of genes for elicitation or biosynthesis of 5-deoxyisoflavonoids suppresses race-specific resistance and hypersensitive cell death in phytophthora sojae infected tissues. | isoflavonoids are thought to play an important role in soybean (glycine max) resistance to phytophthora sojae. this was addressed by silencing two genes for their biosynthesis and a third gene controlling their elicitation. silencing of genes for isoflavone synthase (ifs) or chalcone reductase (chr) was achieved in soybean roots through an agrobacterium rhizogenes-mediated rnai approach. effectiveness of silencing was followed both by quantitative reverse transcriptase-polymerase chain reaction ... | 2007 | 17416637 |
| a symbiotic plant peroxidase involved in bacterial invasion of the tropical legume sesbania rostrata. | aquatic nodulation on the tropical legume sesbania rostrata occurs at lateral root bases via intercellular crack-entry invasion. a gene was identified (srprx1) that is transiently up-regulated during the nodulation process and codes for a functional class iii plant peroxidase. the expression strictly depended on bacterial nodulation factors (nfs) and could be modulated by hydrogen peroxide, a downstream signal for crack-entry invasion. expression was not induced after wounding or pathogen attack ... | 2007 | 17384158 |
| medicago truncatula nin is essential for rhizobial-independent nodule organogenesis induced by autoactive calcium/calmodulin-dependent protein kinase. | the symbiotic association between legumes and nitrogen-fixing bacteria collectively known as rhizobia results in the formation of a unique plant root organ called the nodule. this process is initiated following the perception of rhizobial nodulation factors by the host plant. nod factor (nf)-stimulated plant responses, including nodulation-specific gene expression, is mediated by the nf signaling pathway. plant mutants in this pathway are unable to nodulate. we describe here the cloning and char ... | 2007 | 17369436 |
| hairy root culture for mass-production of high-value secondary metabolites. | plant cell cultivations are being considered as an alternative to agricultural processes for producing valuable phytochemicals. since many of these products (secondary metabolites) are obtained by direct extraction from plants grown in natural habitat, several factors can alter their yield. the use of plant cell cultures has overcome several inconveniences for the production of these secondary metabolites. organized cultures, and especially root cultures, can make a significant contribution in t ... | 2007 | 17364688 |
| cell-cell communication in the plant pathogen agrobacterium tumefaciens. | the plant pathogen agrobacterium tumefaciens induces the formation of crown gall tumours at wound sites on host plants by directly transforming plant cells. this disease strategy benefits the bacteria as the infected plant tissue produces novel nutrients, called opines, that the colonizing bacteria can use as nutrients. almost all of the genes that are required for virulence, and all of the opine uptake and utilization genes, are carried on large tumour-inducing (ti) plasmids. the observation mo ... | 2007 | 17360279 |
| stable transformation and long-term maintenance of transgenic taxus cell suspension cultures. | a cell line of taxus cuspidata has been transformed with wild-type agrobacterium rhizogenes atcc strain 15834 containing binary vector pcambia1301 and, separately, with a. tumefaciens strain eha105 containing binary vector pcambia1305.2. additionally, a cell line of t. chinensis has been transformed with wild-type a. rhizogenes atcc strain 25818 containing binary vector pcambia1301. the two transgenic t. cuspidata cell lines have been maintained in culture for more than 20 months, and the transg ... | 2007 | 17333018 |
| salidroside production by hairy roots of rhodiola sachalinensis obtained after transformation with agrobacterium rhizogenes. | hairy roots induced by agrobacterium rhizogenes grow faster, and are considered as genetically stable. these hairy roots can be used as an interesting material for the production of secondary metabolites of pharmaceutical value. salidroside has been identified as the major compounds from the roots of rhodiola sachalinensis a. bor. here, we provide an update that adds new perspectives on the prospects and challenges of producing salidroside from hairy roots induced by agrobacterium rhizogene in r ... | 2007 | 17329834 |
| characterization of vascular-specific rss1 and rolc promoters for their utilization in engineering plants to develop resistance against hemipteran insect pests. | rice sucrose synthase1, rss1 (isolated from rice) and rolc (isolated from agrobacterium rhizogenes) promoters were evaluated by binding analyses of their respective cis-elements with host nuclear transcription factors. the expression profile of an insecticidal protein driven by these promoters in transgenic plants was monitored. motif-search analysis with available phloem-specific promoter sequences revealed the presence of two boxii elements in rss1. an octopine synthase element, a stem-specifi ... | 2007 | 17323077 |
| tissue distribution, core biosynthesis and diversification of pyrrolizidine alkaloids of the lycopsamine type in three boraginaceae species. | three species of the boraginaceae were studied: greenhouse-grown plants of heliotropium indicum and agrobacterium rhizogenes transformed roots cultures (hairy roots) of cynoglossum officinale and symphytum officinale. the species-specific pyrrolizidine alkaloid (pa) profiles of the three systems were established by gc-ms. all pas are genuinely present as n-oxides. in h. indicum the tissue-specific pa distribution revealed the presence of pas in all tissues with the highest levels in the inflores ... | 2007 | 17320124 |
| a plastid-localized glycogen synthase kinase 3 modulates stress tolerance and carbohydrate metabolism. | glycogen synthase kinase 3 (gsk-3) was originally identified as a regulator of glycogen synthesis in mammals. like starch in plants, glycogen is a polymer of glucose, and serves as an energy and carbon store. starch is the main carbohydrate store in plants. regulation of starch metabolism, in particular in response to environmental cues, is of primary importance for carbon and energy flow in plants but is still obscure. here, we provide evidence that msk4, a novel medicago sativa gsk-3-like kina ... | 2007 | 17319843 |
| nucleoporin85 is required for calcium spiking, fungal and bacterial symbioses, and seed production in lotus japonicus. | in lotus japonicus, seven genetic loci have been identified thus far as components of a common symbiosis (sym) pathway shared by rhizobia and arbuscular mycorrhizal fungi. we characterized the nup85 mutants (nup85-1, -2, and -3) required for both symbioses and cloned the corresponding gene. when inoculated with glomus intraradices, the hyphae managed to enter between epidermal cells, but they were unable to penetrate the cortical cell layer. the nup85-2 mutation conferred a weak and temperature- ... | 2007 | 17307929 |
| hairy root type plant in vitro systems as sources of bioactive substances. | "hairy root" systems, obtained by transforming plant tissues with the "natural genetic engineer" agrobacterium rhizogenes, have been known for more than three decades. to date, hairy root cultures have been obtained from more than 100 plant species, including several endangered medicinal plants, affording opportunities to produce important phytochemicals and proteins in eco-friendly conditions. diverse strategies can be applied to improve the yields of desired metabolites and to produce recombin ... | 2007 | 17294182 |
| the mtmmpl1 early nodulin is a novel member of the matrix metalloendoproteinase family with a role in medicago truncatula infection by sinorhizobium meliloti. | we show here that mtmmpl1, a medicago truncatula nodulin gene previously identified by transcriptomics, represents a novel and specific marker for root and nodule infection by sinorhizobium meliloti. this was established by determining the spatial pattern of mtmmpl1 expression and evaluating gene activation in the context of various plant and bacterial symbiotic mutant interactions. the mtmmpl1 protein is the first nodulin shown to belong to the large matrix metalloendoproteinase (mmp) family. w ... | 2007 | 17293436 |
| [hairy roots induction of phellodendron chinense and production of its active constituents]. | to introduce the hairy roots of phellodendron chinense and determine the content of its active constituents. | 2006 | 17285981 |
| production of hyoscyamine by 'hairy root' cultures of datura stramonium. | 'hairy root' cultures of datura stramonium were established following infection of aseptic leaves with agrobacterium rhizogenes. transformation was confirmed by southern blotting using [ (32)p]-labelled fragments of the t-dna as probes. the transformed cultures grew in the absence of added phytohormones and cell mass increased 55-fold during 28 days incubation. hyoscyamine was a major component of the alkaloid fraction and accounted for at least 0.3% of the dry matter, comparable to pot-grown pl ... | 1987 | 17269071 |
| alkaloid production by transformed root cultures of cinchona ledgeriana. | transformed root cultures of cinchona ledgeriana have been generated by infecting shoots cultured in vitro with agrobacterium rhizogenes lba9402. these root cultures grow axenically in the absence of antibiotics or exogenous plant growth regulators in media containing gamborg b5 salts at half or full strength with 3% (w/v) sucrose as the carbon source. they show a 6- to 8-fold increase in fresh weight in 28 days. transformation has been confirmed by southern blotting using [ (32)p]-labelled frag ... | 1989 | 17262435 |
| influence of agrobacterium rhizogenes strains on biomass and alkaloid productivity in hairy root lines of hyoscyamus muticus and h. albus *. | using leaf explants of in vitro grown hyoscyamus albus and h. muticus plantlets, hairy roots were induced following inoculation with agrobacterium rhizogenes strains a (4) and lba-9402. the transformed roots, appearing after 14 - 17 days incubation on hormone-free ms medium containing 1 g/l cephalexin, were excised and maintained in the same medium. ten randomly selected hairy root lines from each bacterial treatment of the two plant systems were compared for growth and alkaloid production in ha ... | 1999 | 17260237 |
| withanolide production by root cultures of withania somnifera transformed with agrobacterium rhizogenes. | transformed root cultures of withania somnifera dunal (solanaceae) were obtained by infecting shoots cultured in vitro with agrobacterium rhizogenes lba 9402. they grew axenically in the absence of exogenous plant growth regulators in murashige and skoog's medium containing 3% (w/v) sucrose. the root cultures synthesized several withanolides of which withanolide d was isolated and identified. transformed root (clone hr (1)) showed a growth index of 20.07 and a withanolide d yield of 0.30 mg g(-1 ... | 1996 | 17252504 |
| withanolide composition and in vitro culture of italian withania somnifera. | from italian plants of withania somnifera six withanolides were isolated, whose structures allowed us to assign the italian race of w. somnifera to the israel chemotype iii. in vitro cultures of italian w. somnifera under different conditions were obtained, as well as infection by agrobacterium rhizogenes. hplc analysis of in vitro derived tissues showed low contents of withanolides. | 1996 | 17252448 |
| agrobacterium rhizogenes-mediated transformation of artemisia annua: production of transgenic plants. | transgenic hairy roots were induced in the leaves of artemisia annua by treatment with the lba 9402 strain of agrobacterium rhizogenes. the axenic hairy root cultures were found to produce the sesquiterpenes artemisinic acid and arteannuin b. the hairy root cultures were observed to spontaneously regenerate into plantlets on solid hormone-free ms medium. the regenerated plants had phenotypic characteristics typical to the transformed plants. among the plants of the age of one month in culture, t ... | 1997 | 17252369 |
| silencing of pr-10-like proteins in medicago truncatula results in an antagonistic induction of other pr proteins and in an increased tolerance upon infection with the oomycete aphanomyces euteiches. | recent studies on the root proteome of medicago truncatula (gaertn.) showed an induction of pathogenesis-related (pr) proteins of the class 10 after infection with the oomycete pathogen aphanomyces euteiches (drechs.). to get insights into the function of these proteins during the parasitic root-microbe association, a gene knockdown approach using rnai was carried out. agrobacterium rhizogenes-mediated transformation of m. truncatula roots led to a knockdown of the medicago pr10-1 gene in transg ... | 2007 | 17237953 |
| an ire-like agc kinase gene, mtire, has unique expression in the invasion zone of developing root nodules in medicago truncatula. | the agc protein kinase family (camp-dependent protein kinases a, cgmp-dependent protein kinases g, and phospholipid-dependent protein kinases c) have important roles regulating growth and development in animals and fungi. they are activated via lipid second messengers by 3-phosphoinositide-dependent protein kinase coupling lipid signals to phosphorylation of the agc kinases. these phosphorylate downstream signal transduction protein targets. agc kinases are becoming better studied in plants, esp ... | 2007 | 17237187 |
| content of thiophenes in transformed root cultures of argentinian species of tagetes. | the presence of thiophenes in four argentinian species of tagetes was studied. t. terniflora hbk and t. minuta l. seedlings contain 5-(4-hydroxy-1-butynyl)-2-2'-bithienyl (bbtoh); 5-(4-acetoxy-1-butynyl)-2,2'-bithienyl (bbtoac), while t. campanulata griseb and t. laxa cabrera seedlings also accumulated bbt and alpha-t. from the four tagetes species tested only t. laxa was able to produce transformed roots when infected with agrobacterium rhizogenes lba 9402. several clones of transformed roots w ... | 1994 | 17236044 |
| tropane alkaloids in transformed roots of datura quercifolia. | hairy root cultures of datura quercifolia were established following infection with agrobacterium rhizogenes strain lba 9402. eight tropane alkaloids were identified in the hairy roots, hyoscyamine being the major constituent. the growth and the hyoscyamine content of transformed roots were investigated under various conditions. gamborg b5, murashige and skoog, and woody plant media were tested. gamborg b5 medium was the best for growth as well as for hyoscyamine accumulation. the influence of s ... | 1994 | 17236033 |
| tropane alkaloid production in transformed root cultures of brugmansia candida. | transformed root cultures of brugmansia candida were established by infection with agrobacterium rhizogenes lba 9402. several clones with different growth index and tropane alkaloid pattern and content were obtained and two were examined in depth. the alkaloid content and pattern changed during the time course. at 21 days of culture clone 1 revealed an alkaloid spectrum dominated by 3alpha-acetoxytropane (about 50% of the total alkaloid) and hyoscyamine (about 25%), with a ratio of hyoscyamine t ... | 1993 | 17236002 |
| rox1, a gene induced by rolb, is involved in procambial cell proliferation and xylem differentiation in tobacco stamen. | the agrobacterium rhizogenes oncogene rolb mimics the effects of auxin in that it increases the sensitivity of transformed cells to this hormone. here we isolated a tobacco gene, rox1, acting downstream of rolb. we show that plants with reduced levels of rox1 mrna, due to the expression of a 35s-driven rox1-antisense construct, have flowers with stamens and pistils longer than normal because of an increased number of cells. localized expression of rolb in anthers results in overexpression of rox ... | 2007 | 17233794 |
| production of forskolin by axenic coleus forskohlii roots cultivated in shake flasks and 20-l glass jar bioreactors*. | root cultures of coleus forskohlii briq. were initiated from primary callus or iba-treated suspension cultures and maintained on gamborg's b5 medium containing 1 mg/l iba. transformed root cultures were established by infecting surface-sterilized leaves with agrobacterium rhizogenes strain 15834. transformation was confirmed by mannopine detection. these cultures displayed the typical characteristics of hairy root cultures, with the sole exceptions of slow growth in hormone-free medium and accel ... | 1992 | 17226482 |
| accumulation of rare phenylpropanoids in agrobacterium rhizogenes transformed root cultures of coreopsis tinctoria. | 1990 | 17221456 | |
| agrobacterium rhizogenes t-dna genes capable of inducing hairy root phenotype. | segments of the tl-dna of the agropine type ri plasmid pri 1855 encompassing single and groups of open-reading frames were cloned in the ti plasmid-derived binary vector system bin 19. leaf disc infections on nicotiana tabacum led to transformed plants, some of which showed typical hairy root phenotypes, such as the wrinkled leaf morphology, excessive and partially non geotropic root systems and the ability of leaf explants to differentiate roots in a hormone-free culture medium. particularly in ... | 1987 | 17193709 |
| antimicrobial activity of diterpenoids from hairy roots of salvia sclarea l.: salvipisone as a potential anti-biofilm agent active against antibiotic resistant staphylococci. | the antimicrobial activities of crude dichloromethane fractions from acetone extracts of agrobacterium rhizogenes transformed roots and roots of field-grown plants of salvia sclarea as well as four pure abietane diterpenoids isolated from the hairy root cultures were determined. the growth of gram-positive bacteria (staphylococcus aureus, s. epidermidis, enterococcus faecalis) but not gram-negative ones (escherichia coli, pseudomonas aeruginosa) or pathogenic fungi (candida albicans) was inhibit ... | 2007 | 17190643 |
| assessing potential dietary toxicity of heavy metals in selected vegetables and food crops. | heavy metals, such as cadmium, copper, lead, chromium and mercury, are important environmental pollutants, particularly in areas with high anthropogenic pressure. their presence in the atmosphere, soil and water, even in traces can cause serious problems to all organisms, and heavy metal bioaccumulation in the food chain especially can be highly dangerous to human health. heavy metals enter the human body mainly through two routes namely: inhalation and ingestion, ingestion being the main route ... | 2007 | 17173356 |
| assessing potential dietary toxicity of heavy metals in selected vegetables and food crops. | heavy metals, such as cadmium, copper, lead, chromium and mercury, are important environmental pollutants, particularly in areas with high anthropogenic pressure. their presence in the atmosphere, soil and water, even in traces can cause serious problems to all organisms, and heavy metal bioaccumulation in the food chain especially can be highly dangerous to human health. heavy metals enter the human body mainly through two routes namely: inhalation and ingestion, ingestion being the main route ... | 2007 | 17173356 |
| the rolb gene-induced overproduction of resveratrol in vitis amurensis transformed cells. | resveratrol is a stilbene, which prevents carcinogenesis at stages of tumor initiation, promotion and progression. in the present investigation, we developed cell cultures of wild-growing grape (vitis amurensis rupr.). the cultures produced low levels of resveratrol, up to 0.026% dry wt., i.e., comparable to levels reported for other plant cell cultures previously established. different methods commonly used to increase secondary metabolite production (cell selection, elicitor treatments and add ... | 2007 | 17166613 |
| agrobacterium rhizogenes transformation of the phaseolus spp.: a tool for functional genomics. | a fast, reproducible, and efficient transformation procedure employing agrobacterium rhizogenes was developed for phaseolus vulgaris l. wild accessions, landraces, and cultivars and for three other species belonging to the genus phaseolus: p. coccineus, p. lunatus, and p. acutifolius. induced hairy roots are robust and grow quickly. the transformation frequency is between 75 and 90% based on the 35-s promoter-driven green fluorescent protein and beta-glucuronidase expression reporter constructs. ... | 2006 | 17153923 |
| [induction of hairy roots and anthraquinone production in rheum palmatum]. | to study the induction of hairy roots and anthraquinone production in rheum palmatum. | 2006 | 17144464 |
| enzymatic evidence for the key role of arginine in nitrogen translocation by arbuscular mycorrhizal fungi. | key enzymes of the urea cycle and (15)n-labeling patterns of arginine (arg) were measured to elucidate the involvement of arg in nitrogen translocation by arbuscular mycorrhizal (am) fungi. mycorrhiza was established between transformed carrot (daucus carota) roots and glomus intraradices in two-compartment petri dishes and three ammonium levels were supplied to the compartment containing the extraradical mycelium (erm), but no roots. time courses of specific enzyme activity were obtained for gl ... | 2007 | 17142485 |
| a cdpk isoform participates in the regulation of nodule number in medicago truncatula. | medicago spp. are able to develop root nodules via symbiotic interaction with sinorhizobium meliloti. calcium-dependent protein kinases (cdpks) are involved in various signalling pathways in plants, and we found that expression of mtcpk3, a cdpk isoform present in roots of the model legume medicago truncatula, is regulated during the nodulation process. early inductions were detected 15 min and 3-4 days post-inoculation (dpi). the very early induction of cpk3 messengers was also present in inocu ... | 2006 | 17132148 |
| novel type iv secretion system involved in propagation of genomic islands. | type iv secretion systems (t4sss) mediate horizontal gene transfer, thus contributing to genome plasticity, evolution of infectious pathogens, and dissemination of antibiotic resistance and other virulence traits. a gene cluster of the haemophilus influenzae genomic island icehin1056 has been identified as a t4ss involved in the propagation of genomic islands. this t4ss is novel and evolutionarily distant from the previously described systems. mutation analysis showed that inactivation of key ge ... | 2007 | 17122343 |
| novel type iv secretion system involved in propagation of genomic islands. | type iv secretion systems (t4sss) mediate horizontal gene transfer, thus contributing to genome plasticity, evolution of infectious pathogens, and dissemination of antibiotic resistance and other virulence traits. a gene cluster of the haemophilus influenzae genomic island icehin1056 has been identified as a t4ss involved in the propagation of genomic islands. this t4ss is novel and evolutionarily distant from the previously described systems. mutation analysis showed that inactivation of key ge ... | 2007 | 17122343 |
| mthap2-1 is a key transcriptional regulator of symbiotic nodule development regulated by microrna169 in medicago truncatula. | in the model legume medicago truncatula, we identified a new transcription factor of the ccaat-binding family, mthap2-1, for which rna interference (rnai) and in situ hybridization experiments indicate a key role during nodule development, possibly by controlling nodule meristem function. we could also show that mthap2-1 is regulated by microrna169, whose overexpression leads to the same nodule developmental block as mthap2-1 rnai constructs. the complementary expression pattern of mir169 and mt ... | 2006 | 17114582 |
| changes in morphological phenotypes and withanolide composition of ri-transformed roots of withania somnifera. | developmental variability was introduced into withania somnifera using genetic transformation by agrobacterium rhizogenes, with the aim of changing withasteroid production. inoculation of w. somnifera with a. rhizogenes strains lba 9402 and a4 produced typical transformed root lines, transformed callus lines, and rooty callus lines with simultaneous root dedifferentiation and redifferentiation. these morphologically distinct transformed lines varied in t-dna content, growth rates, and withastero ... | 2007 | 17103214 |
| rhizobium lusitanum sp. nov. a bacterium that nodulates phaseolus vulgaris. | the species phaseolus vulgaris is a promiscuous legume nodulated by several species of the family rhizobiaceae. during a study of rhizobia nodulating this legume in portugal, we isolated several strains that nodulate p. vulgaris effectively and also macroptilium atropurpureum and leucaena leucocephala, but they form ineffective nodules in medicago sativa. according to phylogenetic analysis of the 16s rrna gene sequence, the strains from this study belong to the genus rhizobium, with rhizobium rh ... | 2006 | 17082403 |
| lotus japonicus nodulation requires two gras domain regulators, one of which is functionally conserved in a non-legume. | a new nodulation-defective mutant of lotus japonicus does not initiate nodule cortical cell division in response to mesorhizobium loti, but induces root hair deformation, nod factor-induced calcium spiking, and mycorrhization. this phenotype, together with mapping data, suggested that the mutation could be in the ortholog of the medicago truncatula nsp1 gene (mtnsp1). the sequence of the orthologous gene (ljnsp1) in the l. japonicus mutant (ljnsp1-1) revealed a mutation causing a premature stop ... | 2006 | 17071642 |
| caffeic acid derivatives production by hairy root cultures of echinacea purpurea. | inoculation of leaf explants of echinacea purpurea (moench) with agrobacterium rhizogenes induced hairy roots with the capacity to produce biologically active caffeic acid derivatives (cads), especially cichoric acid. the kinetics of growth, the uptake of macronutrients, and the accumulation of cads were investigated in heterotrophically cultured hairy roots for a 50 day period. a maximum of 12.2 g l(-1) dry biomass was achieved in ms nutrients supplemented with 30 g l(-1) sucrose on day 40. the ... | 2006 | 17061821 |
| [study on establishment of system with high frequency for genetic transformation of phellodendron chinese and plant regeneration]. | to establish an effective system for genetic transformation of phellodendron chinese by agrobacterium rhizogenes. | 2006 | 17058995 |
| agrobacterium tumefaciens and agrobacterium rhizogenes transformed roots of the parasitic plant triphysaria versicolor retain parasitic competence. | parasitic plants in the orobanchaceae invade roots of neighboring plants to rob them of water and nutrients. triphysaria is facultative parasite that parasitizes a broad range of plant species including maize and arabidopsis. in this paper we describe transient and stable transformation systems for triphysaria versicolor fischer and c. meyer. agrobacterium tumefaciens and agrobacterium rhizogenes were both able to transiently express a gus reporter in triphysaria seedlings following vacuum infil ... | 2007 | 17053892 |
| [ri plasmid transformation of glycyrrhiza uralensis and effects of some factors on growth of hairy roots]. | to study the induction of hairy roots of glycyrrhiza uralensis and effect of some physical as well as chemical factors on the growth of hairy roots. | 2006 | 17048620 |
| combinatorially selected defense peptides protect plant roots from pathogen infection. | agricultural productivity and sustainability are continually challenged by emerging and indigenous pathogens. currently, many pathogens can be combatted only with biocides or environmentally dangerous fumigants. here, we report a rapid and pathogen-specific strategy to reduce infection by organisms that target plant roots. combinatorially selected defense peptides, previously shown to effect premature encystment of phytophthora capsici zoospores, were fused to maize cytokinin oxidase/dehydrogena ... | 2006 | 17030803 |
| the medicago truncatula cre1 cytokinin receptor regulates lateral root development and early symbiotic interaction with sinorhizobium meliloti. | legumes develop different types of lateral organs from their primary root, lateral roots and nodules, the latter depending on a symbiotic interaction with sinorhizobium meliloti. phytohormones have been shown to function in the control of these organogeneses. however, related signaling pathways have not been identified in legumes. we cloned and characterized the expression of medicago truncatula genes encoding members of cytokinin signaling pathways. rna interference of the cytokinin receptor ho ... | 2006 | 17028204 |
| accumulation of p-hydroxybenzoic acid in hairy roots of daucus carota. | we report here the accumulation of p-hydroxybenzoic acid in agrobacterium rhizogenes-induced hairy root cultures of daucus carota. this phenolic acid finds application in food, pharmaceutical and polymer industries. metabolic profiling of phenolics by hplc/esi-ms from these hairy roots showed a considerable amount of p-hydroxybenzoic acid accumulation both in cytosol and in the cell wall. analyses of hcl and naoh treated soluble phenolic fractions resulted in the elution of peaks with same reten ... | 2007 | 17027117 |
| agrobacterium rhizogenes galls protein contains domains for atp binding, nuclear localization, and type iv secretion. | agrobacterium tumefaciens and agrobacterium rhizogenes are closely related plant pathogens that cause different diseases, crown gall and hairy root. both diseases result from transfer, integration, and expression of plasmid-encoded bacterial genes located on the transferred dna (t-dna) in the plant genome. bacterial virulence (vir) proteins necessary for infection are also translocated into plant cells. transfer of single-stranded dna (ssdna) and vir proteins requires a type iv secretion system, ... | 2006 | 17012398 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| complete plastid genome sequence of daucus carota: implications for biotechnology and phylogeny of angiosperms. | carrot (daucus carota) is a major food crop in the us and worldwide. its capacity for storage and its lifecycle as a biennial make it an attractive species for the introduction of foreign genes, especially for oral delivery of vaccines and other therapeutic proteins. until recently efforts to express recombinant proteins in carrot have had limited success in terms of protein accumulation in the edible tap roots. plastid genetic engineering offers the potential to overcome this limitation, as dem ... | 2006 | 16945140 |
| 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 |
| 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 |
| 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 |
| triterpenes from natural and transformed roots of plocama pendula. | plocama pendula root cultures transformed by agrobacterium rhizogenes were established. from these cultures two new pentacyclic triterpenes, 3-epi-pomolic acid 3alpha-acetate (3alpha-acetoxy-19alpha-hydroxyursa-12-en-28-oic acid) (1) and baloic acid (3alpha-acetoxy-19alpha-hydroxyursa-12,20(30)-dien-28-oic acid) (9), were isolated. the former was also obtained from p. pendula natural roots, together with another two new pentacyclic triterpenes, 3-epi-pomolic acid (3alpha,19alpha-dihydroxyursa-12 ... | 2006 | 16872153 |
| sennosides a and b production by hairy roots of senna alata (l.) roxb. | hairy roots of senna alata transformed with agrobacterium rhizogenes, strain atcc 15834 were induced and grown in half-strength murashige and skoog (ms) medium. effects of sucrose contents and hormones on the growth and sennosides a, b production were investigated. hairy roots cultured on hormone-free half-strength ms medium containing 5% sucrose under dark condition mostly stimulated the growth of hairy roots and increased the content of sennosides a and b yielding (169 +/- 4) and (34 +/- 3) mi ... | 2006 | 16869495 |
| establishment of salvia officinalis l. hairy root cultures for the production of rosmarinic acid. | shoots of salvia officinalis, a medicinally important plant, were infected with agrobacterium rhizogenes strains atcc 15834 and a4 which led to the induction of hairy roots in 57% and 37% of the explants, respectively. seven lines of hairy roots were established in wp liquid medium under light and dark conditions. the transformed nature of the root lines was confirmed by polymerase chain reaction using rolb and rolc specific primers. transformed root cultures of salvia officinalis showed variati ... | 2006 | 16869492 |
| 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 |
| 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 |
| 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 |
| 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 |
| strigolactones stimulate arbuscular mycorrhizal fungi by activating mitochondria. | the association of arbuscular mycorrhizal (am) fungi with plant roots is the oldest and ecologically most important symbiotic relationship between higher plants and microorganisms, yet the mechanism by which these fungi detect the presence of a plant host is poorly understood. previous studies have shown that roots secrete a branching factor (bf) that strongly stimulates branching of hyphae during germination of the spores of am fungi. in the bf of lotus, a strigolactone was found to be the acti ... | 2006 | 16787107 |
| 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 |
| 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 |
| [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 |
| effect of p availability on temporal dynamics of carbon allocation and glomus intraradices high-affinity p transporter gene induction in arbuscular mycorrhiza. | arbuscular mycorrhizal (am) fungi depend on a c supply from the plant host and simultaneously provide phosphorus to the colonized plant. we therefore evaluated the influence of external p on c allocation in monoxenic daucus carota-glomus intraradices cultures in an am symbiosis. fungal hyphae proliferated from a solid minimal medium containing colonized roots into a c-free liquid minimal medium with high or low p availability. roots and hyphae were harvested periodically, and the flow of c from ... | 2006 | 16751522 |
| 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 |
| 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 |
| 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 |