Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
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| comparative structural analysis of a novel glutathiones-transferase (atu5508) from agrobacterium tumefaciens at 2.0 a resolution. | glutathione s-transferases (gsts) comprise a diverse superfamily of enzymes found in organisms from all kingdoms of life. gsts are involved in diverse processes, notably small-molecule biosynthesis or detoxification, and are frequently also used in protein engineering studies or as biotechnology tools. here, we report the high-resolution x-ray structure of atu5508 from the pathogenic soil bacterium agrobacterium tumefaciens (atgst1). through use of comparative sequence and structural analysis of ... | 2006 | 16988933 |
| 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 |
| quorum signal molecules as biosurfactants affecting swarming in rhizobium etli. | swarming motility is suggested to be a social phenomenon that enables groups of bacteria to coordinately and rapidly move atop solid surfaces. this multicellular behavior, during which the apparently organized bacterial populations are embedded in an extracellular slime layer, has previously been linked with biofilm formation and virulence. many population density-controlled activities involve the activation of complex signaling pathways using small diffusible molecules, also known as autoinduce ... | 2006 | 16990436 |
| crystal structure and mechanism of tram2, a second quorum-sensing antiactivator of agrobacterium tumefaciens strain a6. | quorum sensing is a community behavior that bacteria utilize to coordinate a variety of population density-dependent biological functions. in agrobacterium tumefaciens, quorum sensing regulates the replication and conjugative transfer of the tumor-inducing (ti) plasmid from pathogenic strains to nonpathogenic derivatives. most of the quorum-sensing regulatory proteins are encoded within the ti plasmid. among these, trar is a luxr-type transcription factor playing a key role as the quorum-sensing ... | 2006 | 16997969 |
| [a luxr family regulator, expr regulates the expression of motc operon from sinorhizobium meliloti]. | in sinorhizobium meliloti strain rm1021, expr+ mutation results in the overproduction of eps ii, which is required for efficient invasion of root nodules on the host plant alfalfa. when rhizobia were grown in lb/mc medium for 36-hour then placed at room temperature, most of expr+ mutant (rm8530) cells aggregated at the bottom of the tubes, but expr+ sinr double mutant rm11528 and wild type rm1021 did not. the expr+ mutant was also found to swim slower than rm1021 on swarming plates, but the expr ... | 2006 | 16933625 |
| three-dimensional structure of iminodisuccinate epimerase defines the fold of the mmge/prpd protein family. | iminodisuccinate (ids) epimerase catalyzes the epimerisation of r,r-, s,s- and r,s- iminodisuccinate, one step in the biodegradation of the chelating agent iminodisuccinate by agrobacterium tumefaciens by6. the enzyme is a member of the mmge/prpd protein family, a diverse and little characterized class of proteins of prokaryotic and eukaryotic origin. ids epimerase does not show significant overall amino acid sequence similarity to any other protein of known three-dimensional structure. the crys ... | 2006 | 16934291 |
| the alternative sigma factor rpoh2 is required for salt tolerance in sinorhizobium sp. strain bl3. | the objectives of this investigation were to isolate the rpoh2 gene encoding an alternative sigma factor from sinorhizobium sp. bl3 and to determine its role in exopolysaccharide (eps) synthesis, salt tolerance and symbiosis with phaseolus lathyroides. the rpoh2 gene of rhizobium sp. strain tal1145 is known to be required for eps synthesis and effective nodulation of leucaena leucocephala. three overlapping cosmid clones containing the rpoh2 gene of bl3 were isolated by complementing an rpoh2 mu ... | 2006 | 16934437 |
| evidence of frequent integration of non-t-dna vector backbone sequences in transgenic strawberry plant. | we have studied the occurrence of the integration of non-t-dna sequences in transgenic strawberry plants obtained through agrobacterium inoculation. dna from these plants was subjected to pcr amplification of the sequence of the gene trfa, which is located outside the t-dna. the percentage of trfa-positive plants varied from 40% to 90%, with a mean of 65.7%. backbone sequences were confirmed by southern blot analysis. | 2006 | 16935253 |
| rapid in situ evolution of nodulating strains for biserrula pelecinus l. through lateral transfer of a symbiosis island from the original mesorhizobial inoculant. | diverse rhizobia able to nodulate biserrula pelecinus evolved following in situ transfer of noda and nifh from an inoculant to soil bacteria. transfer of these chromosomal genes and the presence of an identical integrase gene adjacent to a phe trna gene in both the inoculant and recipients indicate that there was lateral transfer of a symbiosis island. | 2006 | 16936054 |
| 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 |
| a multi-needle-assisted transformation of soybean cotyledonary node cells. | a new and simple method for wounding cotyledonary node cells of soybean [glycine max (l) merrill] was developed for obtaining a high frequency of transformants. soybean seeds were germinated for 1 day, and the cotyledonary node cells of half-seeds were wounded mechanically by using a multi-needle consisting of thin 30 fibers. the wounded half-seeds were inoculated with agrobacterium tumefaciens cells harboring a recombinant dna that contained the bar and sgfp genes conferring phosphinothricin (p ... | 2006 | 16937246 |
| translocation of tomato bushy stunt virus p19 protein into the nucleus by aly proteins compromises its silencing suppressor activity. | the p19 protein of tomato bushy stunt virus is a potent suppressor of rna silencing and, depending on the host species, is required for short- and long-distance virus movement and symptom production. p19 interacts with plant aly proteins and relocalizes a subset of these proteins from the nucleus to the cytoplasm. here we showed that coexpression by agroinfiltration in nicotiana benthamiana of p19 and the subset of aly proteins that are not relocalized from the nucleus interfered with the abilit ... | 2006 | 16940518 |
| plant growth-promoting methylobacterium induces defense responses in groundnut (arachis hypogaea l.) compared with rot pathogens. | this study, framed in two different phases, studied the plant-growth promotion and the induction of systemic resistance in groundnut by methylobacterium. seed imbibition with methylobacterium sp. increased germination by 19.5% compared with controls. combined inoculation of methylobacterium sp. with rhizobium sp. also significantly increased plant growth, nodulation, and yield attributes in groundnut compared with individual inoculation of rhizobium sp. methylobacterium sp. challenge-inoculated ... | 2006 | 16941245 |
| [molecular basis of brucella persistence]. | this review focuses on brucella persistence. data on brucella--macrophage interaction and the role of molecular-genetic systems including homologues of mos operon rhizobium, a type iv secretion system, a flagellum apparatus and a "quorum sensing"--virulence factors using signal or effector molecules are updated. brucella enters macrophages through lipid raft microdomains, avoids its bactericidal attacks, phagolysosome fusion, expressing a set of virulence genes and inhibits tnf-alpha secretion a ... | 2006 | 16941877 |
| succinic semialdehyde couples stress response to quorum-sensing signal decay in agrobacterium tumefaciens. | quorum sensing (qs) signal decay in agrobacterium tumefaciens occurs in response to starvation or host signals. we have demonstrated that the gamma-aminobutyric acid (gaba) shunt metabolite links stress response to qs signal decay. mutation of the aldh gene encoding a succinic semialdehyde dehydrogenase (ssadh) that converts succinic semialdehyde (ssa) to succinic acid results in early expression of the signal degrading enzyme, attm. exogenous addition of ssa or its precursor gaba induces attm e ... | 2006 | 16942602 |
| exo-oligosaccharides of rhizobium sp. strain ngr234 are required for symbiosis with various legumes. | rhizobia are nitrogen-fixing bacteria that establish endosymbiotic associations with legumes. nodule formation depends on various bacterial carbohydrates, including lipopolysaccharides, k-antigens, and exopolysaccharides (eps). an acidic eps from rhizobium sp. strain ngr234 consists of glucosyl (glc), galactosyl (gal), glucuronosyl (glca), and 4,6-pyruvylated galactosyl (pvgal) residues with beta-1,3, beta-1,4, beta-1,6, alpha-1,3, and alpha-1,4 glycoside linkages. here we examined the role of n ... | 2006 | 16923883 |
| crystal structure of d-psicose 3-epimerase from agrobacterium tumefaciens and its complex with true substrate d-fructose: a pivotal role of metal in catalysis, an active site for the non-phosphorylated substrate, and its conformational changes. | d-psicose, a rare sugar produced by the enzymatic reaction of d-tagatose 3-epimerase (dtease), has been used extensively for the bioproduction of various rare carbohydrates. recently characterized d-psicose 3-epimerase (dpease) from agrobacterium tumefaciens was found to belong to the dtease family and to catalyze the interconversion of d-fructose and d-psicose by epimerizing the c-3 position, with marked efficiency for d-psicose. the crystal structures of dpease and its complex with the true su ... | 2006 | 16876192 |
| core oligosaccharide structure from the highly phytopathogenic agrobacterium tumefaciens tt111 and conformational analysis of the putative rhamnan epitope. | the structure of the complex mixture of the core oligosaccharide components of the lipooligosaccharide (los) fraction of agrobacterium tumefaciens strain tt111 was determined directly on the deacetylated products by means of spectroscopical methods. the rhamnan oligosaccharide elongating the inner kdo residue shares structural features with other polysaccharides from well-known plant pathogenic bacteria. its conformation was determined through extensive molecular dynamic (md) analysis and presen ... | 2006 | 16877750 |
| the biosynthetic pathway for aurofusarin in fusarium graminearum reveals a close link between the naphthoquinones and naphthopyrones. | fungal polyketide biosynthesis typically involves multiple enzymatic steps and the encoding genes are often found in gene clusters. a gene cluster containing pks12, the polyketide synthase gene responsible for the synthesis of the pigment aurofusarin, was analysed by gene replacement using agrobacterium tumefaciens-mediated transformation to determine the biosynthesis pathway of aurofusarin. replacement of aurr1 with hygb shows that it encodes a positively acting transcription factor that is req ... | 2006 | 16879655 |
| purification, crystallization and preliminary crystallographic study of an ids-epimerase from agrobacterium tumefaciens by6. | the initial degradation of all stereoisomers of the complexing agent iminodisuccinate (ids) is enabled by an epimerase in the bacterial strain agrobacterium tumefaciens by6. this protein was produced in escherichia coli, purified and crystallized by the hanging-drop vapour-diffusion method. crystals of ids-epimerase were obtained under several conditions. the best diffracting crystals were grown in 22% peg 3350, 0.2 m (nh4)2so4 and 0.1 m bis-tris propane ph 7.2 at 293 k. these crystals belong to ... | 2006 | 16880546 |
| systemic movement of agrobacterium tumefaciens in several plant species. | the systemic movement of agrobacterium spp. inside plants of different species was studied to determine the most valuable diagnostic methodology for their detection. | 2006 | 16882149 |
| agrobacterium tumefaciens type ii nadh dehydrogenase. characterization and interactions with bacterial and thylakoid membranes. | type ii nadh dehydrogenases (ndh-2) are monomeric enzymes that catalyse quinone reduction and allow electrons to enter the respiratory chain in different organisms including higher plant mitochondria, bacteria and yeasts. in this study, an agrobacterium tumefaciens gene encoding a putative alternative nadh dehydrogenase (atundh-2) was isolated and expressed in escherichia coli as a (his)6-tagged protein. the purified 46 kda protein contains fad as a prosthetic group and oxidizes both nadh and na ... | 2006 | 16884501 |
| crystal structure of glycerophosphodiester phosphodiesterase from agrobacterium tumefaciens by sad with a large asymmetric unit. | 2006 | 16909422 | |
| conversion of a putative agrobacterium sugar-binding protein into a fret sensor with high selectivity for sucrose. | glucose is the main sugar transport form in animals, whereas plants use sucrose to supply non-photosynthetic organs with carbon skeletons and energy. many aspects of sucrose transport, metabolism, and signaling are not well understood, including the route of sucrose efflux from leaf mesophyll cells and transport across vacuolar membranes. tools that can detect sucrose with high spatial and temporal resolution in intact organs may help elucidate the players involved. here, fret sensors were gener ... | 2006 | 16912038 |
| functional expression of the green fluorescent protein in the ectomycorrhizal model fungus hebeloma cylindrosporum. | hebeloma cylindrosporum is a model fungus for mycorrhizal studies because of its fast growth rate, simple nutritional requirements, and completion of its life cycle in vitro, and because it is amenable to transformation. to advance cell biological research during establishment of symbiosis, a tool that would enable the direct visualisation of fusion proteins in the different symbiotic tissues [namely, the expression of reporter genes such as green fluorescent protein (gfp)] was still a missing t ... | 2006 | 16912848 |
| flp-mediated site-specific recombination for genome modification in turfgrass. | to develop molecular strategies for gene containment in genetically modified (gm) turfgrass, we have studied the feasibility of using the flp/frt site-specific dna recombination system from yeast for controlled genome modification in turfgrass. suspension cell cultures of creeping bentgrass (agrostis stolonifera l.) and kentucky bluegrass (poa pratensis) were co-transformed with a flp recombinase expression vector and a recombination-reporter test plasmid containing beta-glucuronidase (gusa) gen ... | 2006 | 16912917 |
| expression of helicobacter pylori urease subunit b gene in transgenic rice. | helicobacter pylori ureb antigen gene was cloned to the 5'-end of gus (beta-glucuronidase) reporter gene between camv35s promoter and the octopine synthase (ocs) terminator in the plasmid, pcambia13011. it was then introduced into rice genome by agrobacterium-mediated transformation. a total of 30 regenerated plants with hygromycin resistance were obtained in the selection media. the putative transgenic individuals were tested for the presence of ureb in the nuclear genome of rice plants by pcr ... | 2006 | 16912927 |
| production of insoluble exopolysaccharide of agrobacterium sp. (atcc 31749 and ifo 13140). | agrobacterium isolated from soil samples produced two extracellular polysaccharides: succinoglycan, an acidic soluble polymer, and curdlan gum, a neutral, insoluble polymer. maize glucose, cassava glucose, and maize maltose were used in fermentation medium to produce insoluble polysaccharide. two agrobacterium sp. strains which were used (atcc 31749 and ifo 13140) in the production of insoluble exopolysaccharide presented equal or superior yields compared to the literature. the strain atcc 31749 ... | 2006 | 16915694 |
| the relaxase of the rhizobium etli symbiotic plasmid shows nic site cis-acting preference. | genetic and biochemical characterization of traa, the relaxase of symbiotic plasmid pretcfn42d from rhizobium etli, is described. after purifying the relaxase domain (n265traa), we demonstrated nic binding and cleavage activity in vitro and thus characterized for the first time the nick site (nic) of a plasmid in the family rhizobiaceae. we studied the range of n265traa relaxase specificity in vitro by testing different oligonucleotides in binding and nicking assays. in addition, the ability of ... | 2006 | 16916896 |
| transformation of metarhizium anisopliae mediated by agrobacterium tumefaciens. | a simple, highly efficient, and reliable agrobacterium tumefaciens-mediated transformation method was developed for the insect pathogenic fungus metarhizium anisopliae. expression of the green fluorescent protein gene, egfp, and the benomyl resistance gene, bena3, were used as markers in transformed m. anisopliae. transformation efficiencies were dependent on the strain of a. tumefaciens used. with strain agl-1, 17.0 +/- 1.4 transformants per plate could be obtained using conidial concentrations ... | 2006 | 16917517 |
| computational estimation and experimental verification of off-target silencing during posttranscriptional gene silencing in plants. | successful application of posttranscriptional gene silencing (ptgs) for gene function study in both plants and animals depends on high target specificity and silencing efficiency. by computational analysis with genome and/or transcriptome sequences of 25 plant species, we predicted that about 50% to 70% of gene transcripts in plants have potential off-targets when used for ptgs that could obscure experimental results. we have developed a publicly available web-based computational tool called sir ... | 2006 | 16920874 |
| a novel type of zinc finger dna binding domain in the agrobacterium tumefaciens transcriptional regulator ros. | transcriptional factors bearing a cys(2)his(2) zinc finger were thought to be confined to eukaryotes, but recent studies have suggested their presence also in prokaryotes. in this paper, we report the first complete functional characterization of the dna binding domain present in the putative cys(2)his(2) zinc finger-containing prokaryotic transcriptional regulator ros from agrobacterium tumefaciens. we demonstrate that in the single zinc binding motif present in the ros protein the metal ion is ... | 2006 | 16922516 |
| the colleflaccinosides, two chiral bianthraquinone glycosides with antitumor activity from the lichen collema flaccidum collected in israel and russia. | colleflaccinosides a and b, two chiral bianthraquinone glycosides from the two geographical varieties of lichen collema flaccidum collected in russia and israel have been isolated as new natural products. their structures were elucidated using uv, cd, ir, ms, 1d and 2d nmr spectral data, and chemical degradation. the colleflaccinosides b had significant antitumor activity in the crown gall tumor inhibition test. | 2006 | 16854728 |
| phase variation and genomic architecture changes in azospirillum. | the plant growth-promoting rhizobacterium azospirillum lipoferum 4b generates in vitro at high frequency a stable nonswimming phase variant designated 4v(i), which is distinguishable from the wild type by the differential absorption of dyes. the frequency of variants generated by a reca mutant of a. lipoferum 4b was increased up to 10-fold. the pleiotropic modifications characteristic of the phase variant are well documented, but the molecular processes involved are unknown. here, the objective ... | 2006 | 16855225 |
| biotransformation of adenine and cytokinins by the rhizobacterium serratia proteamaculans. | approximately 60,000 microorganisms from saskatchewan soil were screened for growth on the cytokinin n6-benzyladenine (ba) as c source. a single isolate, identified as serratia proteamaculans, grew well on ba. the culture filtrates from s. proteamaculans were screened using reversed phase high performance liquid chromatography (rp-hplc) for the presence of secondary metabolites. the analysis revealed a major metabolite and its chemical structure was deduced as 8-hydroxy-n6-benzyladenine (8-ohba) ... | 2006 | 16860349 |
| engineering tce-degrading rhizobacteria for heavy metal accumulation and enhanced tce degradation. | many superfund sites are currently co-contaminated with organic pollutants such as trichloroethene (tce) and heavy metals. a promising strategy to address these mixed-waste situations is the use of tce-degrading rhizobacteria that will survive and thrive in soil heavily polluted with heavy metals. in this work, a gene coding for the metal-binding peptide, ec20, was introduced into rhizobacteria engineered for tce degradation, resulting in strains with both metal accumulation and tce degradation ... | 2006 | 16862598 |
| 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 |
| 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 |
| harnessing the potential of hairy roots: dawn of a new era. | in the past two decades, hairy root research for the production of important secondary metabolites has received a lot of attention. the addition of knowledge to overcome the limiting culture parameters of the regulation of the metabolic pathway by specific molecules and the development of novel tools for metabolic engineering now offer new possibilities to improve the hairy root technique for the production of metabolites. furthermore, engineering hairy roots for the production of animal protein ... | 2006 | 16870285 |
| [chemical composition and immunochemical characteristics of the lipopolysaccharide of nitrogen-fixing rhizobacterium azospirillum brasilense cd]. | the chemical composition of the lipopolysaccharide of the associative diazotrophic rhizobacterium azospirillum brasilense cd has been studied. among the main components of the hydrophobic part of the lipopolysaccharide, we identified 3-hydroxytetradecanoic, hexadecenoic, 3-hydroxyhexadecanoic, hexadecanoic, octadecenoic, and nanodecanoic fatty acids; the carbohydrate part contained rhamnose, galactose, and mannose. polyclonal antibodies against the preparation under study were raised in rabbits. ... | 2006 | 16871806 |
| the chemical synthesis of the gsti protein by ncl on a x-met site. | the small gsti protein (63 amino acids) of rhizobium leguminosarum is the endogenous inhibitor of the glnii (glutamine synthetase ii) gene expression. it has been suggested that gsti has a predominantly beta-structure and mediates the block of translation and stabilization of glnii mrna through direct binding to its 5' untranslated region. because of the unavailability of adequate amounts of purified recombinant protein, the mechanism as well as the protein tridimensional structure remain very p ... | 2006 | 16888773 |
| metabolic engineering of agrobacterium sp. for udp-galactose regeneration and oligosaccharide synthesis. | curdlan-producing agrobacterium sp. is unique in possessing a highly efficient udp-glucose regeneration system. a broad-host-range expression strategy was successfully developed to exploit the unique metabolic capability for udp-galactose regeneration during oligosaccharide synthesis. the engineered agrobacterium cells functioned as a udp-galactose regeneration system, allowing galactose-containing disaccharides to be synthesized from glucose or other simple sugars. unexpectedly, a lag period of ... | 2006 | 16890004 |
| interplay of darwinian and frequency-dependent selection in the host-associated microbial populations. | in order to analyze the microevolutionary processes in host-associated microorganisms, we simulated the dynamics of rhizobia populations composed of a parental strain and its mutants possessing the altered fitness within "plant-soil" system. the population dynamics was presented as a series of cycles (each one involves "soil-->rhizosphere-->nodules-->soil" succession) described using recurrent equations. for representing the selection and mutation pressures, we used a universal approach based on ... | 2006 | 16890259 |
| agrobacterium-mediated transformation of sea urchin embryos. | agrobacterium-mediated transformation of higher plants is a well-known and powerful tool for transgene delivery to plant cells. in the present work, we studied whether agrobacterium can transfer genetic information to animal (sea urchin) embryos. sea urchin embryos were co-cultivated with a. tumefaciens strains carrying binary vectors containing the nptii marker gene and agrobacterial rolc and rolb oncogenes. bacterial plasmid t-dna-sea urchin dna junction sites were identified in the genome of ... | 2006 | 16892273 |
| plant-produced cottontail rabbit papillomavirus l1 protein protects against tumor challenge: a proof-of-concept study. | the native cottontail rabbit papillomavirus (crpv) l1 capsid protein gene was expressed transgenically via agrobacterium tumefaciens transformation and transiently via a tobacco mosaic virus (tmv) vector in nicotiana spp. l1 protein was detected in concentrated plant extracts at concentrations up to 1.0 mg/kg in transgenic plants and up to 0.4 mg/kg in tmv-infected plants. the protein did not detectably assemble into viruslike particles; however, immunoelectron microscopy showed presumptive pent ... | 2006 | 16893983 |
| [host legume genes required for symbiotic nitrogen fixation]. | 2006 | 16895233 | |
| [rhizobial networks for symbiosis with legumes]. | 2006 | 16895234 | |
| biochemical characterization of the decaprenyl diphosphate synthase of rhodobacter sphaeroides for coenzyme q10 production. | coenzyme q(10) (coq(10)), like other coqs of various organisms, plays indispensable roles not only in energy generation but also in several other processes required for cells' survival. in this study, a gene encoding for a decaprenyl diphosphate synthase (rsdds) was cloned from rhodobacter sphaeroides in escherichia coli. the in vivo catalytic activity and product specificity of rsdds were compared with those of a counterpart enzyme from agrobacterium tumefaciens (atdds) in e. coli as a heterolo ... | 2006 | 16896603 |
| endophytic occupation of root nodules and roots of melilotus dentatus by agrobacterium tumefaciens. | agrobacterium strains have been frequently isolated from the root nodules of different legumes. various possible mechanisms have been proposed to explain the existence of these bacteria in nodules, but there is no sufficient experimental evidence to support the estimations. in this work, we proved that the agrobacterium strain ccbau 81181, which was originally isolated from the root nodules of onobrychis viciaefolia, and a symbiotic strain of sinorhizobium meliloti ccbau 10062 could coinhabit th ... | 2006 | 16897296 |
| response of rhizobial populations to moderate copper stress applied to an agricultural soil. | the use of pesticides in agricultural soils may affect the soil microbiota. the effect of repeated application of copper sulfate in soil on indigenous populations of rhizobia was assessed in a medium-term field experiment. copper sulfate was applied over 8 years at two different rates, 12.5 and 50 kg of cuso4 ha(-1) year(-1), in the field. the concentrations of total copper in soil varied between 14.0 (control plots that did not receive copper sulfate) and 91.0 mg kg(-1) (the most contaminated p ... | 2006 | 16897301 |
| screening possible mechanisms mediating cadmium resistance in rhizobium leguminosarum bv. viciae isolated from contaminated portuguese soils. | environment heavy-metal contamination is now widespread. soils may become contaminated from a variety of anthropogenic sources, such as smelters, mining, industry, and application of metal-containing pesticides and fertilizers. soil microorganisms are very sensitive to moderate heavy-metal concentrations. therefore, the present work was designed to screen possible mechanisms involved in rhizobium's cd resistance; with this purpose, we determined the tolerance levels of several isolates originate ... | 2006 | 16897308 |
| scanning electron microscopic observations on micro-organisms in the root nodules of tribulus terrestris l. (zygophyllaceae). | scanning electron microscopic observations were made on the micro-organisms of root nodules of tribulus terrestris l. the results showed that nodules of t. terrestris contained dual infection consisting of rhizobium sp. and newmania karachiensis. based on these observations, t. terrestris should be grouped with nonlegume parasponia-type bacterial nodules. | 2006 | 16898671 |
| structural elucidation and biological activity of acyl-homoserine lactones from the phytopathogen pantoea ananatis serrano 1928. | in gram-negative bacteria, the acyl-homoserine lactones (acyl-hsls) are the main signaling substances employed in cell-to-cell communication systems. this paper describes the chemical characterization of acyl-hsls produced by the worldwide-spread phytopathogen pantoea ananatis (serrano 1928) by using gas chromatography-electron impact mass spectrometry. the absolute configuration of the major identified substance, (s)-(--)-n-hexanoyl-hsl, was determined with gas chromatography-flame ionization d ... | 2006 | 16900431 |
| will you let me use your nucleus? how agrobacterium gets its t-dna expressed in the host plant cell. | agrobacterium is the only known bacterium capable of natural dna transfer into a eukaryotic host. the genes transferred to host plants are contained on a t-dna (transferred dna) molecule, the transfer of which begins with its translocation, along with several effector proteins, from the bacterial cell to the host-cell cytoplasm. in the host cytoplasm, the t-complex is formed from a single-stranded copy of the t-dna (t-strand) associated with several bacterial and host proteins and it is imported ... | 2006 | 16902581 |
| gacs-dependent production of 2r, 3r-butanediol by pseudomonas chlororaphis o6 is a major determinant for eliciting systemic resistance against erwinia carotovora but not against pseudomonas syringae pv. tabaci in tobacco. | root colonization by a plant-beneficial rhizobacterium, pseudomonas chlororaphis o6, induces disease resistance in tobacco against leaf pathogens erwinia carotovora subsp. carotovora scc1, causing soft-rot, and pseudomonas syringae pv. tabaci, causing wildfire. in order to identify the bacterial determinants involved in induced systemic resistance against plant diseases, extracellular components produced by the bacterium were fractionated and purified. factors in the culture filtrate inducing sy ... | 2006 | 16903358 |
| refinement of the citrus tristeza virus resistance gene (ctv) positional map in poncirus trifoliata and generation of transgenic grapefruit (citrus paradisi) plant lines with candidate resistance genes in this region. | citrus tristeza virus (ctv) is a major pathogen of citrus. a single dominant gene ctv present in the trifoliate relative of citrus, poncirus trifoliata confers broad spectrum resistance against ctv. refinement of genetic maps has delimited this gene to a 121 kb region, comprising of ten candidate ctv resistance genes. the ten candidate genes were individually cloned in agrobacterium based binary vector and transformed into three ctv susceptible grapefruit varieties. two of the candidate r-genes, ... | 2006 | 16830176 |
| insights into recognition of the t-dna border repeats as termination sites for t-strand synthesis by agrobacterium tumefaciens. | the recognition of the t-dna left border (lb) repeat is affected by its surrounding sequences. here, the lb regions were further characterized by molecular analysis of transgenic plants, obtained after agrobacterium tumefaciens-mediated transformation with t-dna vectors that had been modified in this lb region. at least the 24-bp lb repeat by itself was insufficient to terminate the t-strand synthesis. addition of the natural inner and/or outer border regions to at least the lb repeat, even when ... | 2006 | 16830227 |
| transformation of barley (hordeum vulgare l.) by agrobacterium tumefaciens infection of in vitro cultured ovules. | we report on a novel transformation procedure for barley by agrobacterium infection of in vitro cultured ovules. ovules of the cultivar golden promise were isolated a few hours after pollination and infected with the agrobacterium tumefaciens strain agl0 carrying the binary vector pvec8-gfp. the vector harboured a hygromycin resistance gene and the green fluorescence protein (gfp) gene. gfp-expressing embryos were isolated from the ovules, regenerated to plants and investigated by southern blot ... | 2006 | 16832622 |
| peddling the nitrogen cycle. | 2006 | 16835960 | |
| factors contributing to deletion within mungbean yellow mosaic virus partial dimers in binary vectors used for agroinoculation. | mungbean yellow mosaic virus-vigna (mymv) sequences cloned as partial dimers within the t-dna of a binary vector were deleted at a high frequency upon conjugal mobilization from escherichia coli into agrobacterium tumefaciens. this deletion involving the genome-length viral dna did not occur when the binary plasmid was inside e. coli and when the binary plasmid was introduced into agrobacterium by electroporation. deletions occurred in both dna a and dna b partial dimers. a minimum of 500-nt con ... | 2006 | 16837070 |
| 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 |
| isolation and characterization of functional insertion sequences of rhizobia. | rhizobia are a group of bacteria that form nodules on the roots of legume host plants. the sequenced genomes of the rhizobia are characterized by the presence of many putative insertion sequences (is) elements. however, it is unknown whether these is elements are functional and it is therefore relevant to assess their transposition activity. in this work, several functional insertion sequences belonging to the is1256, is3, is5, is166, and is21 families were captured from rhizobium tropici, rhizo ... | 2006 | 16842354 |
| postgenomic scan of metallo-beta-lactamase homologues in rhizobacteria: identification and characterization of bjp-1, a subclass b3 ortholog from bradyrhizobium japonicum. | the diffusion of metallo-beta-lactamases (mbls) among clinically important human pathogens represents a therapeutic issue of increasing importance. however, the origin of these resistance determinants is largely unknown, although an important number of proteins belonging to the mbl superfamily have been identified in microbial genomes. in this work, we analyzed the distribution and function of genes encoding mbl-like proteins in the class rhizobiales. among 12 released complete genomes of member ... | 2006 | 16723554 |
| 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 |
| in vitro regeneration and agrobacterium-mediated genetic transformation of euonymus alatus. | an in vitro plant regeneration method and an agrobacterium tumefaciens-mediated genetic transformation protocol were developed for euonymus alatus. more than 60% of cotyledon and 70% of hypocotyl sections from 10-day-old seedlings of e. alatus produced 2-4 shoots on woody plant medium (wpm) supplemented with 5.0 mg/l 6-benzylaminopurine (ba) plus 0.2 mg/l alpha-naphthalene acetic acid (naa), and 77% of shoots produced roots on wpm medium with 0.3 mg/l naa and 0.5 mg/l indole-3-butyricacid (iba). ... | 2006 | 16733742 |
| functional effects of amino acid substitutions within the large binding pocket of the phosphotriesterase opda from agrobacterium sp. p230. | the phosphotriesterase opda from agrobacterium sp. p230 has about 10-fold higher activity for dimethyl organophosphate (op) insecticides, than its homologue from flavobacterium sp. atcc27551, organophosphate hydrolase (oph). opda shows about 10% amino acid sequence divergence from oph and also has a 20 residue c-terminal extension. here we show that the difference in kinetics is largely explained by just two amino acid differences between the two proteins. a truncated form of opda demonstrated t ... | 2006 | 16734778 |
| synchronization, transformation, and cryopreservation of suspension-cultured cells. | we have recently described the selection of rapidly dividing arabidopsis cell suspension cultures mm1 and mm2d that provide a powerful platform for plant cell-cycle research. here we provide detailed protocols and procedures to achieve high levels of synchronization, either by starving the cell cultures of sucrose or by applying the toxin aphidicolin. cell-cycle activity during cell-cycle reentry (starvation-induced synchrony) or further cell-cycle progression (aphidicolin-induced synchrony) can ... | 2006 | 16739567 |
| in planta agrobacterium-mediated transformation by vacuum infiltration. | in planta agrobacterium-mediated transformation using vacuum infiltration results in transgenic arabidopsis thaliana without the use of sterile conditions or plant regeneration. plants are grown in pots, in standard potting mix. agrobacterium tumefaciens, carrying an appropriate plant transformation vector, is suspended in an infiltration medium that contains, at a minimum, sucrose and the surfactant silwet l-77. flower buds are immersed in the suspension of a. tumefaciens. the application of a ... | 2006 | 16739579 |
| transient expression assay by agroinfiltration of leaves. | an agrobacterium-mediated transient expression assay has been described for in vivo analysis of constitutive or inducible gene expression in arabidopsis plants. by simple infiltration of agrobacterium cells carrying appropriate gene constructs into arabidopsis leaves, transient expression assays can be performed within 3 d without using expensive instruments or complicated procedures. two days after agroinfiltration, arabidopsis plants can be treated with chemical inducers such as dexamethasone ... | 2006 | 16739580 |
| proteome changes after metabolic engineering to enhance aerobic mineralization of cis-1,2-dichloroethylene. | metabolically engineered escherichia coli has previously been used to degrade cis-1,2-dichloroethylene (cis-dce). the strains express the six genes of an evolved toluene ortho-monooxygenase from burkholderia cepacia g4 (tom-green, which formed a reactive epoxide) with either (1) gamma-glutamylcysteine synthetase (gshi, which forms glutathione) and the glutathione s-transferase isoilr1 from rhodococcus ad45 (which adds glutathione to the reactive cis-dce epoxide) or (2) with an evolved epoxide hy ... | 2006 | 16739990 |
| transgenic expression of gallerimycin, a novel antifungal insect defensin from the greater wax moth galleria mellonella, confers resistance to pathogenic fungi in tobacco. | a cdna encoding gallerimycin, a novel antifungal peptide from the greater wax moth galleria mellonella, was isolated from a cdna library of genes expressed during innate immune response in the caterpillars. upon ectopic expression of gallerimycin in tobacco, using agrobacterium tumefaciens as a vector, gallerimycin conferred resistance to the fungal pathogens erysiphe cichoracearum and sclerotinia minor. quantification of gallerimycin mrna in transgenic tobacco by real-time pcr confirmed transge ... | 2006 | 16740126 |
| proteins exported via the prsd-prse type i secretion system and the acidic exopolysaccharide are involved in biofilm formation by rhizobium leguminosarum. | the type i protein secretion system of rhizobium leguminosarum bv. viciae encoded by the prsd and prse genes is responsible for secretion of the exopolysaccharide (eps)-glycanases plya and plyb. the formation of a ring of biofilm on the surface of the glass in shaken cultures by both the prsd and prse secretion mutants was greatly affected. confocal laser scanning microscopy analysis of green-fluorescent-protein-labeled bacteria showed that during growth in minimal medium, r. leguminosarum wild ... | 2006 | 16740954 |
| crystallization and preliminary x-ray analysis of an exotype alginate lyase atu3025 from agrobacterium tumefaciens strain c58, a member of polysaccharide lyase family 15. | almost all alginate lyases depolymerize alginate in an endolytical fashion via a beta-elimination reaction. the alginate lyase atu3025 from agrobacterium tumefaciens strain c58, consisting of 776 amino-acid residues, is a novel exotype alginate lyase classified into polysaccharide lyase family 15. the enzyme was crystallized at 293 k by sitting-drop vapour diffusion with polyethylene glycol 4000 as a precipitant. preliminary x-ray analysis showed that the atu3025 crystal belonged to space group ... | 2006 | 16682783 |
| factors affecting the attachment of rhizospheric bacteria to bean and soybean roots. | the plant rhizosphere is an important soil ecological environment for plant-microorganism interactions, which include colonization by a variety of microorganisms in and around the roots that may result in symbiotic, endophytic, associative, or parasitic relationships within the plant, depending on the type of microorganisms, soil nutrient status, and soil environment. rhizosphere competence may be attributable to the differences in the extent of bacterial attachment to the root surface. we prese ... | 2006 | 16684104 |
| [adsorption mechanism of chromium cation by floc-type biosorbent zl 5-2]. | biosorption of cr(vi) by the novel biosorbent zl5-2 produced by agrobacterium sp. was studied and infrared spectra of native, absorbing and desorbing zl 5-2 were compared. the initial ph was important for biosorption. the optimum effect on cr(vi) biosorption was acquired within initial ph 0.5 to approximately 1.5, then with the ph increasing, the effect on cr6+ biosorption was reduced. the biosorption for cr(vi) was a quick process,only within 10 min 65.4% cr(vi) is biosorbed, and the biosorptio ... | 2006 | 16686202 |
| anomalous scattering analysis of agrobacterium radiobacter phosphotriesterase: the prominent role of iron in the heterobinuclear active site. | bacterial phosphotriesterases are binuclear metalloproteins for which the catalytic mechanism has been studied with a variety of techniques, principally using active sites reconstituted in vitro from apoenzymes. here, atomic absorption spectroscopy and anomalous x-ray scattering have been used to determine the identity of the metals incorporated into the active site in vivo. we have recombinantly expressed the phosphotriesterase from agrobacterium radiobacter (opda) in escherichia coli grown in ... | 2006 | 16686603 |
| o-acetylation of the terminal n-acetylglucosamine of the lipooligosaccharide inner core in neisseria meningitidis. influence on inner core structure and assembly. | o-acetylation is a common decoration on endotoxins derived from many gram-negative bacterial species, and it has been shown to be instrumental (e.g. in salmonella typhimurium) in determining the final tertiary structure of the endotoxin and the immunogenicity of the molecule. structural heterogeneity of endotoxins produced by mucosal pathogens such as neisseria meningitidis is determined by decorations on the heptose inner core, including o-acetylation of the terminal n-acetylglucosamine (glcnac ... | 2006 | 16687398 |
| molecular diversity of rhizobia nodulating the invasive legume cytisus scoparius in australia. | to contribute to the understanding of cytisus scoparius success at invading and establishing itself in australia. | 2006 | 16696670 |
| antioxidative enzymes from chloroplasts, mitochondria, and peroxisomes during leaf senescence of nodulated pea plants. | in this work the influence of the nodulation of pea (pisum sativum l.) plants on the oxidative metabolism of different leaf organelles from young and senescent plants was studied. chloroplasts, mitochondria, and peroxisomes were purified from leaves of nitrate-fed and rhizobium leguminosarum-nodulated pea plants at two developmental stages (young and senescent plants). in these cell organelles, the activity of the ascorbate-glutathione cycle enzymes ascorbate peroxidase (apx), monodehydroascorba ... | 2006 | 16698815 |
| reactive oxygen and nitrogen species and glutathione: key players in the legume-rhizobium symbiosis. | several reactive oxygen and nitrogen species (ros/rns) are continuously produced in plants as by-products of aerobic metabolism or in response to stresses. depending on the nature of the ros and rns, some of them are highly toxic and rapidly detoxified by various cellular enzymatic and non-enzymatic mechanisms. whereas plants have many mechanisms with which to combat increased ros/rns levels produced during stress conditions, under other circumstances plants appear to generate ros/rns as signall ... | 2006 | 16698817 |
| the role of phb metabolism in the symbiosis of rhizobia with legumes. | the carbon storage polymer poly-beta-hydroxybutyrate (phb) is a potential biodegradable alternative to plastics, which plays a key role in the cellular metabolism of many bacterial species. most species of rhizobia synthesize phb but not all species accumulate it during symbiosis with legumes; the reason for this remains unclear, although it was recently shown that a metabolic mutant of a nonaccumulating species retains the capacity to store phb in symbiosis. although the precise roles of phb me ... | 2006 | 16703322 |
| transformation of the entomopathogenic fungus paecilomyces fumosoroseus with agrobacterium tumefaciens. | to test the suitability of the agrobacterium tumefaciens-mediated transformation (amt) method with paecilomyces fumosoroseus, a fungal pathogen that causes diseases in a wide range of insects including whiteflies. | 2006 | 16706904 |
| identification of genistein-inducible and type iii-secreted proteins of bradyrhizobium japonicum. | flagellin is the bulk protein secreted by bradyrhizobium japonicum. for easier identification of minor protein fractions, the flagellin genes bll6865 and bll6866 were deleted. extracellular proteins of the corresponding mutant were purified and separated by 2d gel electrophoresis. several of the protein spots were detectable only after addition of genistein to the growth medium-genistein is an isoflavone secreted by soybean that activates the expression of genes encoding a type iii secretion sys ... | 2006 | 16707185 |
| 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 |
| flavonoid-inducible modifications to rhamnan o antigens are necessary for rhizobium sp. strain ngr234-legume symbioses. | rhizobium sp. strain ngr234 produces a flavonoid-inducible rhamnose-rich lipopolysaccharide (lps) that is important for the nodulation of legumes. many of the genes encoding the rhamnan part of the molecule lie between 87 degrees and 110 degrees of pngr234a, the symbiotic plasmid of ngr234. computational methods suggest that 5 of the 12 open reading frames (orfs) within this arc are involved in synthesis (and subsequent polymerization) of l-rhamnose. two others probably play roles in the transpo ... | 2006 | 16672619 |
| agrobacterium-mediated transformation of petunia leaf discs. | many dicotyledonous and also several monocotyledonous plant species are susceptible to agrobacterium-mediated transformation. this current and well-established method has been used successfully with a large number of plant species to mediate gene transfer. this chapter describes an agrobacterium-mediated transformation method of petunia hybrida leaf discs, one of the first species that was routinely transformed using this method. | 2006 | 16673922 |
| transformation of maize via agrobacterium tumefaciens using a binary co-integrate vector system. | this chapter describes a stepwise protocol to achieve success in genetic transformation of maize using agrobacterium tumefaciens as a dna delivery system. researchers will be able to effectively transform immature embryos of hi-ii and related genotypes with this protocol. the outcome of the transformation process will be transgenic embryogenic callus tissue, transgenic plants, and transgenic progeny seeds. recommendations for molecular confirmation and evaluation of transgenic tissue/plants are ... | 2006 | 16673926 |
| methods for regeneration and transformation in eschscholzia californica: a model plant to investigate alkaloid biosynthesis. | eschscholzia californica cham. (california poppy) is a plant species that accumulates pharmacologically active alkaloids biosynthetically related to the morphinan alkaloids of papaver somniferum. this, in combination with the relative ease with which it is propagated in vitro, makes it a key model for benzylisoquinoline biosynthesis. transformation techniques are an important tool for these studies and for metabolic engineering attempts. agrobacterium mediated transformation techniques for this ... | 2006 | 16673930 |
| the rhizobium leguminosarum biovar trifolii anu794 induces novel developmental responses on the subterranean clover cultivar woogenellup. | the clover-nodulating rhizobium leguminosarum bv. trifolii anu794 initiates normal root-nodule development with abnormally low efficiency on the trifolium subterraneum cv. woogenellup. the cellular and developmental responses of woogenellup roots to the site- and dose-defined inoculation of green fluorescent protein (gfp)-labeled cells of anu843 (nodulation proficient) and anu794 was investigated using light, fluorescence, and confocal microscopy. strain anu794-gfp induced three primordia types ... | 2006 | 16673934 |
| biological significance and development of practical synthesis of biotin. | biotin (1), a water-soluble b series vitamin, distributes widely in microorganisms, plants, and animals. biosynthesis of 1 involves five steps sequence starting from pimelic acid. the last step, a transformation from dethiobiotin (dtb) to 1, includes an iron clusters-mediated radical process. the compound 1 is a cofactor of carboxylation enzymes and plays crucial roles in the metabolism of fatty acids, sugars, and alpha-amino acids. in addition to the increasing application to feed additives, re ... | 2006 | 16676358 |
| agrobacterium tumefaciens and plant cell interactions and activities required for interkingdom macromolecular transfer. | host recognition and macromolecular transfer of virulence-mediating effectors represent critical steps in the successful transformation of plant cells by agrobacterium tumefaciens. this review focuses on bacterial and plant-encoded components that interact to mediate these two processes. first, we examine the means by which agrobacterium recognizes the host, via both diffusible plant-derived chemicals and cell-cell contact, with emphasis on the mechanisms by which multiple host signals are recog ... | 2006 | 16709150 |
| improved agrobacterium-mediated transformation of three maize inbred lines using ms salts. | transformation technology as a research or breeding tool to improve maize is routinely used in most industrial and some specialized public laboratories. however, transformation of many inbred lines remains a challenging task, especially when using agrobacterium tumefaciens as the delivery method. here we report success in generating transgenic plants and progeny from three maize inbred lines using an agrobacterium-mediated standard binary vector system to target maize immature embryos. eleven ma ... | 2006 | 16710703 |
| perception of the bacterial pamp ef-tu by the receptor efr restricts agrobacterium-mediated transformation. | higher eukaryotes sense microbes through the perception of pathogen-associated molecular patterns (pamps). arabidopsis plants detect a variety of pamps including conserved domains of bacterial flagellin and of bacterial ef-tu. here, we show that flagellin and ef-tu activate a common set of signaling events and defense responses but without clear synergistic effects. treatment with either pamp results in increased binding sites for both pamps. we used this finding in a targeted reverse-genetic ap ... | 2006 | 16713565 |
| a frameshift in the coding region of a novel tomato class i basic chitinase gene makes it a pseudogene with a functional wound-responsive promoter. | a putative class i basic chitinase gene, assigned as psibch, was cloned from a tomato breeding line nc 24e. the gene contains a coding region with two introns. the predicted psibch open reading frame (orf) is 971 bp and exhibits 81-88% identity at the nucleotide level with known class i basic chitinase genes from the solanaceae family. however, the presence of a stop codon caused by a frameshift in the orf of psibch makes it unusual among the other class i plant basic chitinases. this stop codon ... | 2006 | 16716538 |
| constitutive expression exposes functional redundancy between the arabidopsis histone h2a gene hta1 and other h2a gene family members. | the arabidopsis thaliana histone h2a gene hta1 is essential for efficient transformation of arabidopsis roots by agrobacterium tumefaciens. disruption of this gene in the rat5 mutant results in decreased transformation. in arabidopsis, histone h2a proteins are encoded by a 13-member gene family. rna encoded by these genes accumulates to differing levels in roots and whole plants; hta1 transcripts accumulate to levels up to 1000-fold lower than do transcripts of other hta genes. we examined the e ... | 2006 | 16751347 |
| 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 |
| potential of a 16s rrna-based taxonomic microarray for analyzing the rhizosphere effects of maize on agrobacterium spp. and bacterial communities. | bacterial diversity is central to ecosystem sustainability and soil biological function, for which the role of roots is important. the high-throughput analysis potential of taxonomic microarray should match the breadth of bacterial diversity. here, the power of this technology was evidenced through methodological verifications and analysis of maize rhizosphere effect based on a 16s rrna-based microarray developed from the prototype of h. sanguin et al. (environ. microbiol. 8:289-307, 2006). the ... | 2006 | 16751545 |
| subterfuge and manipulation: type iii effector proteins of phytopathogenic bacteria. | diverse gram-negative bacteria deliver effector proteins into the cells of their eukaryotic hosts using the type iii secretion system. collectively, these type iii effector proteins function to optimize the host cell environment for bacterial growth. type iii effector proteins are essential for the virulence of pseudomonas syringae, xanthomonas spp., ralstonia solanacearum and erwinia species. type iii secretion systems are also found in nonpathogenic pseudomonads and in species of symbiotic nit ... | 2006 | 16753033 |
| the regulatory function of the upstream sequence of the beta-conglycinin alpha subunit gene in seed-specific transcription is associated with the presence of the ry sequence. | beta-conglycinin, a major component of seed-storage proteins in soybean, comprises three subunits: alpha, alpha', and beta. expression of these genes is spatially regulated in a stringent manner and occurs during seed development. to understand the mechanisms that control expression of the alpha subunit gene, we analyzed the nucleotide sequence of the 2.9-kb region upstream of the gene. the upstream sequence up to -1357 or a series of its 5'-deleted derivatives was fused to the beta-glucuronidas ... | 2006 | 16755137 |
| [transgenic wheat (triticum aestivum l.) with increased resistance to the storage pest obtained by agrobacterium tumefaciens--mediated]. | the transgenic wheat of improved resistance to the storage pest was production. we have introduced the cowpea trypsin inhibitor gene (cpti) into cultured embryonic callus cells of immature embryos of wheat elite line by agrobacterium-mediated method. independent plantlets were obtained from the kanamycin-resistant calli after screening. pcr and real time pcr analysis, pcr-southern and southern blot hybridization indicated that there were 3 transgenic plants viz. transformed- i, ii and iii (t- i, ... | 2006 | 16755923 |