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heavy metal resistance and genotypic analysis of metal resistance genes in gram-positive and gram-negative bacteria present in ni-rich serpentine soil and in the rhizosphere of alyssum murale.forty-six bacterial cultures, including one culture collection strain, thirty from the rhizosphere of alyssum murale and fifteen from ni-rich soil, were tested for their ability to tolerate arsenate, cadmium, chromium, zinc, mercury, lead, cobalt, copper, and nickel in their growth medium. the resistance patterns, expressed as minimum inhibitory concentrations, for all cultures to the nine different metal ions were surveyed by using the agar dilution method. a large number of the cultures were r ...200717276484
a novel ankyrin-repeat membrane protein, ign1, is required for persistence of nitrogen-fixing symbiosis in root nodules of lotus japonicus.nitrogen-fixing symbiosis of legume plants with rhizobium bacteria is established through complex interactions between two symbiotic partners. similar to the mutual recognition and interactions at the initial stages of symbiosis, nitrogen fixation activity of rhizobia inside root nodules of the host legume is also controlled by specific interactions during later stages of nodule development. we isolated a novel fix(-) mutant, ineffective greenish nodules 1 (ign1), of lotus japonicus, which forms ...200717277093
okadaic acid and trifluoperazine enhance agrobacterium-mediated transformation in eastern white pine.mature zygotic embryos of recalcitrant christmas tree species eastern white pine (pinus strobus l.) were used as explants for agrobacterium tumefaciens strain gv3101-mediated transformation using the uida (beta-glucuronidase) gene as a reporter. influence of the time of sonication and the concentrations of protein phosphatase inhibitor (okadaic acid) and kinase inhibitor (trifluoperazine) on agrobacterium-mediated transformation have been evaluated. a high transformation frequency was obtained a ...200717242943
a germin-like protein with superoxide dismutase activity in pea nodules with high protein sequence identity to a putative rhicadhesin receptor.the cdnas encoding three germin-like proteins (psger1, psger2a, and psger2b) were isolated from pisum sativum. the coding sequence of psger1 transiently expressed in tobacco leaves gave a protein with superoxide dismutase activity but no detectable oxalate oxidase activity according to in-gel activity stains. the transient expression of wheat germin gf-2.8 oxalate oxidase showed oxalate oxidase but no superoxide dismutase activity under the same conditions. the superoxide dismutase activity of p ...200717244628
nmr structure of a complex between the virb9/virb7 interaction domains of the pkm101 type iv secretion system.type iv secretion (t4s) systems translocate dna and protein effectors through the double membrane of gram-negative bacteria. the paradigmatic t4s system in agrobacterium tumefaciens is assembled from 11 virb subunits and vird4. two subunits, virb9 and virb7, form an important stabilizing complex in the outer membrane. we describe here the nmr structure of a complex between the c-terminal domain of the virb9 homolog trao (trao(ct)), bound to virb7-like tran from plasmid pkm101. trao(ct) forms a b ...200717244707
agrobacterium rubi(t) dsm 6772 produces a lipophilic polysaccharide capsule whose degree of acetylation is growth modulated.the structure of the capsular polysaccharide produced from the type strain of agrobacterium rubi dsm 6772 is demonstrated by means of chemical and spectroscopical methodologies. it is constituted from the quite rare monosaccharide 6-deoxy-l-talose, involved in alternating alpha-(1 --> 2) and alpha-(1 --> 3) linkages. this simple backbone is further complicated from the occurrence of o-acetyl substituents located always at o-2 of the o-3 substituted 6-deoxy-talose. this decoration is not stoichio ...200717284069
gene targeting in gram-negative bacteria by use of a mobile group ii intron ("targetron") expressed from a broad-host-range vector.mobile group ii introns ("targetrons") can be programmed for insertion into virtually any desired dna target with high frequency and specificity. here, we show that targetrons expressed via an m-toluic acid-inducible promoter from a broad-host-range vector containing an rk2 minireplicon can be used for efficient gene targeting in a variety of gram-negative bacteria, including escherichia coli, pseudomonas aeruginosa, and agrobacterium tumefaciens. targetrons expressed from donor plasmids introdu ...200717322321
crystal structure of agr_c_4470p from agrobacterium tumefaciens.we report here the crystal structure at 2.0 a resolution of the agr_c_4470p protein from the gram-negative bacterium agrobacterium tumefaciens. the protein is a tightly associated dimer, each subunit of which bears strong structural homology with the two domains of the heme utilization protein chus from escherichia coli and hems from yersinia enterocolitica. remarkably, the organization of the agr_c_4470p dimer is the same as that of the two domains in chus and hems, providing structural evidenc ...200717322535
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 ...200717323077
chemolithoautotrophic oxidation of thiosulfate, tetrathionate and thiocyanate by a novel rhizobacterium belonging to the genus paracoccus.two tropical leguminous-rhizospheric strains, sst and jt 001, phylogenetically closest to paracoccus thiocyanatus and paracoccus pantotrophus, respectively, were isolated on reduced sulfur compounds as sole energy and electron sources. while sst had versatile chemolithotrophic abilities to oxidize thiosulfate, tetrathionate, thiocyanate, sulfide and elemental sulfur, jt 001 could oxidize thiosulfate, soluble sulfide, elemental sulfur and a relatively lesser amount of tetrathionate. positive hybr ...200717326754
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 ...200717329834
microbial enzymes involved in lactone compound metabolism and their biotechnological applications.lactone compounds are widely distributed in nature and play important roles in organisms. these compounds are synthesized and metabolized enzymatically in vivo; however, detailed investigation of these enzymes lags behind that of other common enzymes. in this paper, recent work on the enzymes involved in the metabolism of lactone compounds will be reviewed. in particular, fundamental and application studies on lactonases and baeyer-villiger monooxgenases of microbial origin are described.200717333168
[t-dna-induced mutations in transgenic plants].the review surveys experimental data on changes of individual traits in genetically modified (transgenic) plants. the attention is focused on mutations induced by t-dna insertions upon agrobacterium-induced transformation of dicotyledonous plants. the character of mutation appearance in transgenic plants is examined. the prospects of mutations induced by t-dna insertions are considered.200717333933
verification and rapid identification of soybean rhizobia in indian soils.sixty root nodule isolates of soybean rhizobia indigenous to eight field sites in india were characterized using pcr-rflp for repeated sequence rsalpha a 1195-bp dna fragment, indole acetic acid production, and nitrogenase activity. site-dependent variations were observed in terms of iaa production and nitrogenase activities. rsalpha was conserved in slow-growing soybean rhizobia across locations and sites and was absent in other rhizobiaceae members and other bacterial genera. the results sugge ...200717334844
making a friend from a foe: expressing a groel gene from the whitefly bemisia tabaci in the phloem of tomato plants confers resistance to tomato yellow leaf curl virus.some (perhaps all) plant viruses transmitted in a circulative manner by their insect vectors avoid destruction in the haemolymph by interacting with groel homologues, ensuring transmission. we have previously shown that the phloem-limited begomovirus tomato yellow leaf curl virus (tylcv) interacts in vivo and in vitro with groel produced by the whitefly vector bemisia tabaci. in this study, we have exploited this phenomenon to generate transgenic tomato plants expressing the whitefly groel in th ...200717334947
protein conformational changes of agrobacterium phytochrome agp1 during chromophore assembly and photoconversion.phytochromes are widely distributed photochromic biliprotein photoreceptors. typical bacterial phytochromes such as agrobacterium agp1 have a c-terminal histidine kinase module; the n-terminal chromophore module induces conformational changes in the protein that lead to modulation of kinase activity. we show by protein cross-linking that the c-terminal histidine kinase module of agp1 mediates stable dimerization. the fragment agp1-m15, which comprises the chromophore module but lacks the histidi ...200717335289
inhibition of lipid a biosynthesis as the primary mechanism of chir-090 antibiotic activity in escherichia coli.the deacetylation of udp-3-o-[(r)-3-hydroxymyristoyl]-n-acetylglucosamine (udp-3-o-acyl-glcnac) by lpxc is the committed reaction of lipid a biosynthesis. chir-090, a novel n-aroyl-l-threonine hydroxamic acid, is a potent, slow, tight-binding inhibitor of the lpxc deacetylase from the hyperthermophile aquifex aeolicus, and it has excellent antibiotic activity against pseudomonas aeruginosa and escherichia coli, as judged by disk diffusion assays. we now report that chir-090 is also a two-step sl ...200717335290
evolving ideas of legume evolution and diversity: a taxonomic perspective on the occurrence of nodulation.legumes evolved about 60 million years ago (ma), and nodulation 58 ma. nonnodulation remains common in caesalpinioideae, with smaller numbers in mimosoideae and papilionoideae. the first type of infection by bacteria may have been at junctions where lateral roots emerged, followed by formation of infection threads to confine bacteria and convey them to some cells in the developing nodule, where they were generally released into symbiosomes. infection threads were a prerequisite for root-hair inf ...200717335493
silencing of beta-carotene hydroxylase increases total carotenoid and beta-carotene levels in potato tubers.beta-carotene is the main dietary precursor of vitamin a. potato tubers contain low levels of carotenoids, composed mainly of the xanthophylls lutein (in the beta-epsilon branch) and violaxanthin (in the beta-beta branch). none of these carotenoids have provitamin a activity. we have previously shown that tuber-specific silencing of the first step in the epsilon-beta branch, lcy-e, redirects metabolic flux towards beta-beta carotenoids, increases total carotenoids up to 2.5-fold and beta-caroten ...200717335571
genome-wide functional analysis of pathogenicity genes in the rice blast fungus.rapid translation of genome sequences into meaningful biological information hinges on the integration of multiple experimental and informatics methods into a cohesive platform. despite the explosion in the number of genome sequences available, such a platform does not exist for filamentous fungi. here we present the development and application of a functional genomics and informatics platform for a model plant pathogenic fungus, magnaporthe oryzae. in total, we produced 21,070 mutants through l ...200717353894
molecular diversity of legume root-nodule bacteria in kakadu national park, northern territory, australia.symbiotic relationships between leguminous plants (family fabaceae) and nodule-forming bacteria in australia native ecosystems remain poorly characterized despite their importance. most studies have focused on temperate parts of the country, where the use of molecular approaches have already revealed the presence of bradyrhizobium, ensifer (formerly sinorhizobium), mesorhizobium and rhizobium genera of legume root-nodule bacteria. we here provide the first molecular characterization of nodulatin ...200717356689
quorum-sensing regulation in rhizobia and its role in symbiotic interactions with legumes.legume-nodulating bacteria (rhizobia) usually produce n-acyl homoserine lactones, which regulate the induction of gene expression in a quorum-sensing (or population-density)-dependent manner. there is significant diversity in the types of quorum-sensing regulatory systems that are present in different rhizobia and no two independent isolates worked on in detail have the same complement of quorum-sensing genes. the genes regulated by quorum sensing appear to be rather diverse and many are associa ...200717360278
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 ...200717360279
[obtaining marker-free transgenic soybean plants with optimal frequency by constructing three t-dnas binary vector].obtaining marker-free plants with high efficiency will benefit the environmental release of transgenic crops. to achieve this point, a binary vector pnb35svip1 with three t-dnas was constructed by using several mediate plasmids, in which one copy of bar gene expression cassette and two copies of vip1 gene expression cassette were included. eha101 agrobacterium strain harboring the final construct was applied to transform soybean (glycine max) cotyledon nodes. through 2 - 3 months regeneration an ...200717366903
traa, trac and trad autorepress two divergent quorum-regulated promoters near the transfer origin of the ti plasmid of agrobacterium tumefaciens.whole-genome transcriptional profiling experiments were performed to identify the complete set of trar-regulated genes in isogenic a. tumefaciens strains containing an octopine-type or nopaline-type ti plasmid. most of the known trar-regulated genes as well as a number of new inducible genes were identified. surprisingly, some known members of this regulon showed both weaker induction and weak levels of expression than we had predicted based upon earlier studies. in particular, traa was expresse ...200717367394
caspase-resistant vird2 protein provides enhanced gene delivery and expression in plants.agrobacterium tumefaciens vird2 protein is one of the key elements of agrobacterium-mediated plant transformation, a process of transfer of t-dna sequence from the agrobacterium tumour inducing plasmid into the nucleus of infected plant cells and its integration into the host genome. the vird2 protein has been shown to be a substrate for a plant caspase-like protease activity (pclp) in tobacco. we demonstrate here that mutagenesis of the vird2 protein to prevent cleavage by pclp increases the ef ...200717370074
hrt and nutrients affect bacterial communities grown on recirculation aquaculture system effluents.in a recirculation aquaculture system the drumfilter effluent can be used as substrate for heterotrophic bacterial production, which can be recycled as feed. because the bacteria might contain pathogens, which could reduce its suitability as feed, it is important to characterize these communities. bacteria were produced in growth reactors under different conditions: 7 h hydraulic retention time (hrt) vs. 2 h, sodium acetate vs. molasses, and ammonia vs. nitrate. the community of the drumfilter e ...200717371322
characterization of t-dna insertion patterns in the genome of rice blast fungus magnaporthe oryzae.agrobacterium tumefaciens-mediated transformation (atmt) has been proven to be a powerful strategy for gene disruption in plants and fungi. patterns associated with transferred dna (t-dna) integration in plants and yeast have been studied comprehensively, whereas no detailed analysis of t-dna integration has been reported yet in filamentous fungi. here, we reported the t-dna insertion patterns in the genome of filamentous fungus magnaporthe oryzae. using atmt, a t-dna tagged population consistin ...200717372735
[the pssa gene encodes udp-glucose: polyprenyl phosphate-glucosyl phosphotransferase initiating biosynthesis of rhizobium leguminosarum exopolysaccharide].symbiotic nitrogen-fixing bacteria rhizobium leguminosarum by. viciae vf39 secrete an acidic heteropolysaccharide, the biosynthesis of which involves the stage of polyprenyl diphosphate octasaccharide formation, with its carbohydrate fragment corresponding to the repeating polymer unit. the amino acid analysis of the product of the pssa gene, we have earlier identified, showed its homology to bacterial polyisoprenyl phosphate hexose 1-phosphate transferases catalyzing the formation of phosphodie ...200717375671
the quorum-sensing transcription factor trar decodes its dna binding site by direct contacts with dna bases and by detection of dna flexibility.trar of agrobacterium tumefaciens is a member of the luxr family of transcriptional regulators, and binds to specific dna sequences (tra boxes) at target promoters of the tumour-inducing (ti) plasmid. each tra box has a pronounced dyad symmetry, and each subunit of a trar dimer binds to one half of a tra box via a helix-turn-helix (hth) dna binding motif. structural analysis has suggested that trar makes extensive sequence-specific contacts with tra box dna. in this study, we tested these predic ...200717376086
symbiosis-induced cascade regulation of the mesorhizobium loti r7a virb/d4 type iv secretion system.the mesorhizobium loti r7a symbiosis island contains genes encoding a virb/d4 type iv secretion system (t4ss) similar to that of agrobacterium tumefaciens. this system has host-dependent effects on symbiosis that probably are due to translocation of two effector proteins, msi059 and msi061, into host cells. here we report that, as in a. tumefaciens, the m. loti vir genes are transcriptionally regulated by a vira/virg two-component regulatory system. a virgn54d mutant gene of m. loti caused const ...200717378428
rhizobium-initiated rice growth inhibition caused by nitric oxide accumulation.isolates of rhizobium leguminosarum bv. trifolii (the clover root-nodule endosymbiont) from the nile river delta have been found to infect rice roots and colonize the intercellular spaces of the rice roots. some of these isolates inhibit rice seedling growth but one in particular, r4, has been found in rice roots which develop and grow normally. we present evidence that the induced growth inhibition is due to a toxic accumulation of nitric oxide (no), from the reduction of nitrate, and suggest t ...200717378431
rhizobium tropici response to acidity involves activation of glutathione synthesis.rhizobium tropici ciat899 displays intrinsic tolerance to acidity, and efficiently nodulates phaseolus vulgaris at low ph. by characterizing a gshb mutant strain, glutathione has been previously demonstrated to be essential for r. tropici tolerance to acid stress. the wild-type gshb gene region has been cloned and its transcription profile has been characterized by using quantitative real-time pcr and transcriptional gene fusions. activation of the gshb gene under acid-stress conditions was demo ...200717379738
suppressor of rna silencing encoded by the monopartite tomato leaf curl java begomovirus.we previously isolated the monopartite begomovirus tomato leaf curl java virus (tolcjav) and satellite dnabeta02 from the same naturally infected tomato source in indonesia. tolcjav induced mild leaf curl symptoms in nicotiana benthamiana plants; dnabeta02 encoded the betac1 gene and produced severe leaf curl symptoms when co-inoculated with tolcjav in n. benthamiana. however, dnabeta02mbetac1, which contains a frame shift mutation, did not induce severe symptoms in n. benthamiana when co-inocul ...200717385070
response of inoculated foliar fed pea plants (pisum sativum l.) to reduced mo supply.the application of nutrients to the roots and leaves of inoculated pea plants grown under conditions of reduced mo supply was studied. pea plants (pisum sativum l.) were grown on liquid nutrient solution excluding mo from the media until the 35th day under glasshouse conditions. plants were inoculated with the bacterial suspension of rhizobium leguminosarum bv. vicae, strain d293 at approximately 10(8) cells per cm3. the foliar fertilizer agroleaf was applied at 0.3% concentration. changes in th ...200717385546
reconstitution of the biochemical activities of the attj repressor and the attk, attl, and attm catabolic enzymes of agrobacterium tumefaciens.the attklm operon encodes a lactonase (attm) that hydrolyzes acylhomoserine lactone autoinducers, as well as two putative dehydrogenases (attk and attl). here we show that attk, attl, and attm collectively covert gamma-butyrolactone to succinate. two metabolic intermediates, gamma-hydroxybutyrate and succinic semialdehyde, inactivated the attj repressor in vitro and induced attklm transcription in vivo.200717307843
new insights into microbial oxidation of antimony and arsenic.sb(iii) oxidation was documented in an agrobacterium tumefaciens isolate that can also oxidize as(iii). equivalent sb(iii) oxidation rates were observed in the parental wild-type organism and in two well-characterized mutants that cannot oxidize as(iii) for fundamentally different reasons. therefore, despite the literature suggesting that sb(iii) and as(iii) may be biochemical analogs, sb(iii) oxidation is catalyzed by a pathway different than that used for as(iii). sb(iii) and as(iii) oxidation ...200717308197
purification and characterization of mannose/glucose-specific lectin from seeds of trigonella foenumgraecum.a lectin present in seeds of trigonella foenumgraecum was isolated and purified by acid precipitation, salt fractionation, and affinity chromatography on mannan cross-linked agarose. sds-page revealed a single band corresponding to a molecular weight of 27,350 daltons. the lectin agglutinated trypsin-treated rat erythrocytes. sugar specificity as determined by hemagglutination inhibition assay indicated that the lectin belongs to a glucose/mannose-specific group. the reaction of the lectin with ...200717309436
development of a simple and rapid agrobacterium tumefaciens-mediated transformation system for the entomopathogenic fungus metarhizium anisopliae var. acridum.to examine the ability of agrobacterium to attach to metarhizium anisopliae var. acridum strain cg423 under co-cultivation and to develop an agrobacterium-mediated method of gene delivery into strain cg423, a promising agent for biological control of grasshoppers.200717309500
genetic diversity of rhizobia associated with desmodium species grown in china.desmodia are leguminous plants used as important forage and herbal medicine in china. little information is available about the nodule bacteria of desmodium species. to understand the genetic diversity of rhizobia associated with desmodium species grown in china, isolates from temperate and subtropical regions were obtained and analysed.200717309506
coupling two mercury resistance genes in eastern cottonwood enhances the processing of organomercury.eastern cottonwood (populus deltoides bartr. ex marsh.) trees were engineered to express mera (mercuric ion reductase) and merb (organomercury lyase) transgenes in order to be used for the phytoremediation of mercury-contaminated soils. earlier studies with arabidopsis thaliana and nicotiana tabacum showed that this gene combination resulted in more efficient detoxification of organomercurial compounds than did merb alone, but neither species is optimal for long-term field applications. leaf dis ...200717309680
[calcium and nod signaling]. 200717291420
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 ...200717293436
improved expression of recombinant gfp using a replicating vector based on beet curly top virus in leaf-disks and infiltrated nicotiana benthamiana leaves.recombinant green fluorescent protein (gfp) with a molecular mass of 29 kda was transiently expressed in agrobacterium-inoculated leaf-disks prepared from nicotiana benthamiana plants. expression of gfp from the cauliflower mosaic virus (camv) 35 s promoter within a replicating vector based on the geminivirus beet curly top virus (bctv) was more than 3 times higher than from a control, non-replicating vector. use of the cassava vein mosaic virus (csvmv) promoter in the bctv replicating vector in ...200717294255
production of transgenic strawberries by temporary immersion bioreactor system and verification by tail-pcr.strawberry (fragaria x ananassa) is an economically important soft fruit crop with polyploid genome which complicates the breeding of new cultivars. for certain traits, genetic engineering offers a potential alternative to traditional breeding. however, many strawberry varieties are quite recalcitrant for agrobacterium-mediated transformation, and a method allowing easy handling of large amounts of starting material is needed. also the genotyping of putative transformants is challenging since th ...200717309794
transient beta-glucuronidase expression in lily (lilium longflorum l.) pollen via wounding-assisted agrobacterium-mediated transformation.a pollen-based transient expression system has been developed. lily pollen grains, wounded by vigorous shaking in the presence of aluminum oxide particles, were transformed by infiltration with agrobacterium tumefaciens lba4404 cells harboring the beta-glucuronidase (gus) gene construct, pbi121. in histochemical and fluorometric gus analysis, the wounding processes allowed efficient transformation and, in cdna blot hybridization, gus mrna synthesis was clearly detected. lily pollen with appropri ...200717310322
living without fur: the subtlety and complexity of iron-responsive gene regulation in the symbiotic bacterium rhizobium and other alpha-proteobacteria.the alpha-proteobacteria include several important genera, including the symbiotic n(2)-fixing "rhizobia", the plant pathogen agrobacterium, the mammalian pathogens brucella, bartonella as well as many others that are of environmental or other interest--including rhodobacter, caulobacter and the hugely abundant marine genus pelagibacter. only a few species--mainly different members of the rhizobia--have been analyzed directly for their ability to use and to respond to iron. these studies, howeve ...200717310401
bacillus megaterium rhizobacteria promote growth and alter root-system architecture through an auxin- and ethylene-independent signaling mechanism in arabidopsis thaliana.soil microorganisms are critical players in plant-soil interactions at the rhizosphere. we have identified a bacillus megaterium strain that promoted growth and development of bean (phaseolus vulgaris) and arabidopsis thaliana plants. we used arabidopsis thaliana as a model to characterize the effects of inoculation with b. megaterium on plant-growth promotion and postembryonic root development. b. megaterium inoculation caused an inhibition in primary-root growth followed by an increase in late ...200717313171
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 ...200717053892
plant transformation by agrobacterium tumefaciens: modulation of single-stranded dna-vire2 complex assembly by vire1.agrobacterium tumefaciens infects plant cells by the transfer of dna. a key factor in this process is the bacterial virulence protein vire2, which associates stoichiometrically with the transported single-stranded (ss) dna molecule (t-strand). as observed in vitro by transmission electron microscopy, vire2-ssdna readily forms an extended helical complex with a structure well suited to the tasks of dna protection and nuclear import. here we have elucidated the role of the specific molecular chape ...200717060320
production and characterization of anti-(mucin muc1) single-domain antibody in tobacco (nicotiana tabacum cultivar xanthi).members of the camelidae (camels, dromedaries, llamas, alpacas, guanacos and vicunas) are known to produce igs (immunoglobulins) devoid of light chains and ch1s (constant heavy-chain domains). the antigen-specific binding fragments of these heavy-chain antibodies therefore comprise one single domain (the so-called 'vhh') and are of great importance in biotechnological applications. to evaluate the expression and biological activity of sdabs (single-domain antibodies) in plants, which, on account ...200717073735
contribution of invariant residues to the function of rgg family transcription regulators.the rgg family of transcription regulators is widely distributed among gram-positive bacteria, yet how these proteins control transcription is poorly understood. using streptococcus pyogenes ropb as a model, we demonstrated that residues invariant among rgg-like regulators are critical for function and obtained evidence for a mechanism involving protein complex formation.200717098902
earlier flowering induced by over-expression of co gene does not accompany increase of artemisinin biosynthesis in artemisia annua.the early flowering gene constans (co) from arabidopsis thaliana was transferred into artemisia annua using the agrobacterium tumefaciens-mediated transformation system. the plant expression vector pbi co was constructed by inserting the co gene into the binary vector pbi121 under the control of camv 35s promoter. analyses of pcr, pcr southern blot, and southern blot revealed that the transgenic plants contained the foreign co gene. the results of rt-pct and rt-pcr southern blot suggested that t ...200717099845
transgene-dependent incompatibility induced by introduction of the sk2:zpt2-10 chimeric gene in petunia.in an attempt to functionally characterize a petunia zinc-finger gene zpt2-10, which is specifically expressed in style transmitting tissue, we fused its cdna downstream of the potato sk2 promoter (sk2:zpt2-10) and then introduced it into petunia hybrida. we found that some transformants had acquired altered traits in compatibility in mating; these were termed 'transgene-dependent incompatibility (tdi)'. these transgenic lines were fertile when self-pollinated or crossed with other tdi lines. in ...200717103023
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 ...200717103214
engineering resistance to pvy in different potato cultivars in a marker-free transformation system using a 'shooter mutant' a. tumefaciens.in this work, potato virus y (pvy) resistant potatoes were generated using an environmentally safe construct. for this purpose, a 'shooter' mutant agrobacterium-based transformation system was used. the isopentenyl transferase gene (ipt) present on the ti plasmid of 'shooter' strains enhances shoot regeneration and can be used as a phenotypic selection marker. the introduced marker-free binary vector carried a hairpin construct derived from the coat protein gene of pvy-ntn strain in order to ind ...200717103215
production of sirna targeted against tylcv coat protein transcripts leads to silencing of its expression and resistance to the virus.the coat protein (cp) of tomato yellow leaf curl virus (tylcv), encoded by the v1 gene, is the only known component of the viral capsid. in addition, the cp plays a role in the virus transport into the host cell nucleus where viral genes are replicated and transcribed. in this study, we analyzed the effect of small interfering double-stranded rnas (sirnas), derived from an intron-hairpin rna (ihprna) construct and targeting the v1 gene product, on cp accumulation. transient assays involving agro ...200717103242
overexpression of barley hva1 gene in creeping bentgrass for improving drought tolerance.the objectives of this study were to test the feasibility of introducing barley hva1 gene, a lea3 member, into perennial grass species using the agrobacterium-mediated transformation technique and to determine whether heterologous expression of hva1 would alleviate water-deficit injury in grass species. creeping bentgrass (agrostis stolonifera var. palustris), a drought-intolerant grass species, was transformed transiently or stably using three different promoters in conjunction with the downstr ...200717106681
a cytokinin perception mutant colonized by rhizobium in the absence of nodule organogenesis.in legumes, nod-factor signaling by rhizobia initiates the development of the nitrogen-fixing nodule symbiosis, but the direct cell division stimulus that brings about nodule primordia inception in the root cortex remains obscure. we showed that lotus japonicus plants homozygous for a mutation in the hyperinfected 1 (hit1) locus exhibit abundant infection-thread formation but fail to initiate timely cortical cell divisions in response to rhizobial signaling. we demonstrated that the correspondin ...200717110535
rhizobium etli usda9032 engineered to produce a phenazine antibiotic inhibits the growth of fungal pathogens but is impaired in symbiotic performance.phenazine production was engineered in rhizobium etli usda9032 by the introduction of the phz locus of pseudomonas chlororaphis o6. phenazine-producing r. etli was able to inhibit the growth of botrytis cinerea and fusarium oxysporum in vitro. black bean inoculated with phenazine-producing r. etli produced brownish fix(-) nodules.200717085692
directed evolution and structural analysis of n-carbamoyl-d-amino acid amidohydrolase provide insights into recombinant protein solubility in escherichia coli.one of the greatest bottlenecks in producing recombinant proteins in escherichia coli is that over-expressed target proteins are mostly present in an insoluble form without any biological activity. dcase (n-carbamoyl-d-amino acid amidohydrolase) is an important enzyme involved in semi-synthesis of beta-lactam antibiotics in industry. in the present study, in order to determine the amino acid sites responsible for solubility of dcase, error-prone pcr and dna shuffling techniques were applied to r ...200717121498
highly conserved residues asp-197 and his-250 in agp1 phytochrome control the proton affinity of the chromophore and pfr formation.the mutants h250a and d197a of agp1 phytochrome from agrobacterium tumefaciens were prepared and investigated by different spectroscopic and biochemical methods. asp-197 and his-250 are highly conserved amino acids and are part of the hydrogen-bonding network that involves the chromophore. both substitutions cause a destabilization of the protonated chromophore in the pr state as revealed by resonance raman and uv-visible absorption spectroscopy. titration experiments demonstrate a lowering of t ...200717121858
optimization of culture conditions and scale-up to pilot and plant scales for coenzyme q10 production by agrobacterium tumefaciens.this report describes the optimization of culture conditions for coenzyme q(10) (coq(10)) production by agrobacterium tumefaciens kccm 10413, an identified high-coq(10)-producing strain (kim et al., korean patent. 10-0458818, 2002b). among the conditions tested, the ph and the dissolved oxygen (do) levels were the key factors affecting coq(10) production. when the ph and do levels were controlled at 7.0 and 0-10%, respectively, a dry cell weight (dcw) of 48.4 g l(-1) and a coq(10) production of ...200717124579
functional expression of escherichia coli fhua gene in rhizobium spp. of cajanus cajan provides growth advantage in presence of fe3+: ferrichrome as iron source.cajanus cajan rhizobial isolates were found to be unable to utilize iron bound to ferrichrome, desferrioxamine b or rhodotorulic acid, all being hydroxamate type siderophores. a broad host range expression vector containing the escherichia coli fhua gene, encoding the outer membrane receptor for fe-ferrichrome, was constructed. the plasmid construct (pgr1), designed to express fhua under the lac promoter of e. coli, complemented e. coli mb97 deltafhua mutant for ferri-ferrichrome utilization and ...200717136381
modulation of the venation pattern of cotyledons of transgenic tobacco for the tumorigenic 6b gene of agrobacterium tumefaciens ake10.neoplastic plant-tissue formation, termed crown gall disease, is induced on infection with agrobacterium tumefaciens. the tumorous tissues develop an extensive vascular system, with a venation pattern distinct from that of native host plants. we report here that the plant-tumorigenic 6b gene of the a. tumefaciens strain ake10 is capable of inducing extensive vein formation in transgenic tobacco seedlings with distinct pattern formation. unlike the wild-type cotyledons, transgenic cotyledons had ...200717136474
use of dna marker to select well-adapted phaseolus-symbionts strains under acid conditions and high temperature.soil acidity and high temperature contribute to the failure of nodulation in the common bean. it is therefore urgent to select strains with a high competitive ability under these stress conditions. two egyptian rhizobium etli strains, ebri 2 and ebri 26, were examined against rhizobium tropici ciat 899g labeled with the gus (beta-glucuronidase) reporter gene. ebri 2 and ebri 26 were less competitive than ciat 899g under acid conditions with both the egyptian cultivar giza 3 and the colombian cul ...200717136573
development of genotype-independent regeneration system for transformation of rice (oryza sativa ssp. indica).rice (oryza sativa ssp. indica) is an important economic crop in many countries. although a variety of conventional methods have been developed to improve this plant, manipulation by genetic engineering is still complicated. we have established a system of multiple shoot regeneration from rice shoot apical meristem. by use of ms medium containing 4 mg l(-1) thidiazuron (tdz) multiple shoots were successfully developed directly from the meristem without an intervening callus stage. all rice culti ...200717139419
towards the elucidation of am-specific transcription in medicago truncatula.roots of most plants form a mutualistic interaction with arbuscular mycorrhiza (am) fungi. during the symbiosis, drastic morphological and physiological changes occur in the host plant root system. these changes are likely to be controlled by a specific genetic program of the plant. the legume medicago truncatula is a model system widely used to elucidate this program. a number of loci required for am-development have been identified by the analysis of m. truncatula mutants; however, the genes i ...200717141285
transposition-based plant transformation.agrobacterium t-dnas were used to deliver transposable dissociation (ds) elements into the nuclei of potato (solanum tuberosum) cells. a double-selection system was applied to enrich for plants that only contained a transposed ds element. this system consisted of a positive selection for the neomycin phosphotransferase (nptii) gene positioned within ds followed by a negative selection against stable integration of the cytosine deaminase (coda) gene-containing t-dna. sixteen of 29 transgenic plan ...200717142486
in planta akt2 subunits constitute a ph- and ca2+-sensitive inward rectifying k+ channel.heterologous expression of plant genes in yeast and animal cells represents a common approach to study plant ion channels. when expressed in xenopus oocytes and cos cells the arabidopsis shaker-like k+ channel, akt2 forms a weakly voltage-dependent channel, blocked by ca2+ and protons. channels with these characteristics, however, were not found in akt2-expressing arabidopsis cell types. to understand this phenomenon, we employed agrobacterium-mediated transient transformation to functionally ch ...200717146665
origin of the bacterial set domain genes: vertical or horizontal?the presence of supressor of variegation-enhanser of zeste-trithorax (set) domain genes in bacteria is a current paradigm for lateral genetic exchange between eukaryotes and prokaryotes. because a major function of set domain proteins is the chemical modification of chromatin and bacteria do not have chromatin, there is no apparent functional requirement for the existence of bacterial set domain genes. consequently, their finding in only a small fraction of pathogenic and symbiotic bacteria was ...200717148507
strain-specific salt tolerance and osmoregulatory mechanisms in azospirillum brasilense.salinity stress inhibits the growth and nitrogen fixation ability of the plant growth-promoting rhizobacterium azospirillum brasilense. five strains of a. brasilense were isolated from the rhizosphere of indian cereals and grasses and identified on the basis of their phenotypic features and 16s rrna gene sequence. the five indian isolates and two standard strains of a. brasilense, sp7 and cd, showed notable differences in growth, acetylene-reducing activity under salt stress, and ability to take ...200717156127
genetic transformation and gene silencing mediated by multiple copies of a transgene in eastern white pine.an efficient transgenic eastern white pine (pinus strobus l.) plant regeneration system has been established using agrobacterium tumefaciens strain gv3850-mediated transformation and the green fluorescent protein (gfp) gene as a reporter in this investigation. stable integration of transgenes in the plant genome of pine was confirmed by polymerase chain reaction (pcr), southern blot, and northern blot analyses. transgene expression was analysed in pine t-dna transformants carrying different numb ...200717158108
biochemical and genetic analysis of the gamma-resorcylate (2,6-dihydroxybenzoate) catabolic pathway in rhizobium sp. strain mtp-10005: identification and functional analysis of its gene cluster.we identified a gene cluster that is involved in the gamma-resorcylate (2,6-dihydroxybenzoate) catabolism of the aerobic bacterium rhizobium sp. strain mtp-10005. the cluster consists of the grardafcbek genes, and graa, grab, grac, and grad were heterologously expressed in escherichia coli. enzymological studies showed that grad, graa, grac, and grab encode the reductase (grad) and oxygenase (graa) components of a resorcinol hydroxylase (ec 1.14.13.x), a maleylacetate reductase (grac) (ec 1.3.1. ...200717158677
the major chemotaxis gene cluster of rhizobium leguminosarum bv. viciae is essential for competitive nodulation.rhizobium leguminosarum biovar viciae strain 3841 is a motile alpha-proteobacterium that can establish a nitrogen-fixing symbiosis within the roots of pea plants. in order to determine the contribution of chemotaxis to the lifestyle of r. leguminosarum, we have characterized the function of two chemotaxis gene clusters (che1 and che2) in controlling motility behaviour. we have found that both chemotaxis gene clusters modulate the motility swimming bias of r. leguminosarum cells and that the che1 ...200717163982
the usefulness of the gfp reporter gene for monitoring agrobacterium-mediated transformation of potato dihaploid and tetraploid genotypes.potato is one of the main targets for genetic improvement by gene transfer. the aim of the present study was to establish a robust protocol for the genetic transformation of three dihaploid and four economically important cultivars of potato using agrobacterium tumefaciens carrying the in vivo screenable reporter gene for green fluorescent protein (gfp) and the marker gene for neomycin phosphotransferase (nptii). stem and leaf explants were used for transformation by agrobacterium tumefaciens st ...200717165042
stable agrobacterium-mediated genetic transformation of london plane tree (platanus acerifolia willd.).london plane tree (platanus acerifolia willd.) is an important tree in urban landscaping but it suffers from a number of negative traits which genetic engineering could be used to address. as with many woody species, p. acerifolia has appeared recalcitrant to genetic transformation. however, the recent development of a method for regenerating shoots from p. acerifolia leaf explants suggests that such material could be a target for gene-transfer. using an agrobacterium tumefaciens strain in which ...200717165043
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 ...200717166613
use of rna interference to dissect defense-signaling pathways in rice.the rna interference (rnai) technique is a powerful tool to suppress gene expression and has been widely used for functional discovery of eukaryotic genes. to dissect defense-signaling pathways in rice, it is important to generate a series of rice mutant lines deficient in or insensitive to major signal molecules such as jasmonic acid and ethylene. here we describe an rnai protocol for generating and characterizing transgenic gene-silencing lines defective in rice jasmonic acid signaling. the rn ...200717172753
virus-induced gene silencing in plant roots.virus-induced gene silencing (vigs) has been used as a quick and easy tool to assess gene function in plants. the virus, carrying a portion of an endogenous gene, triggers a homology-based defense mechanism when introduced into plants. infection with the modified virus results in gene-specific transcript degradation. several virus-based vectors have been developed for use in vigs. one of these virus vectors, tobacco rattle virus (trv), has a large host range and is transmitted by phytopathogenic ...200717172754
the symbiotic ion channel homolog dmi1 is localized in the nuclear membrane of medicago truncatula roots.legumes utilize a common signaling pathway to form symbiotic associations both with rhizobial bacteria and arbuscular mycorrhizal fungi. the perception of microbial signals is believed to take place at the plasma membrane, activating a cascade that converges on the nucleus where transcriptional reprogramming facilitates the symbioses. forward genetic strategies have identified genes in this signaling pathway including medicago truncatula dmi1 (doesn't make infections 1) that encodes a putative i ...200717173544
superexpression of tuberculosis antigens in plant leaves.recent developments in genetic engineering allow the employment of plants as factories for 1/foreign protein production. thus, tuberculosis (tb) esat6 antigen was expressed in different plant systems, but the level of vaccine protein accumulation was extremely low. we describe the technology for superexpression of tb vaccine proteins (ag85b, esat6, and esat6:ag85b fusion) in plant leaves which involves: (i) construction of tobacco mosaic virus-based vectors with the coat protein genes substitute ...200717182283
rhizosphere-bacterial community in eperua falcata (caesalpiniaceae) a putative nitrogen-fixing tree from french guiana rainforest.the rainforest of french guiana is still largely unaffected by human activity. various pristine sites like the paracou research station are devoted to study this tropical ecosystem. we used culture-independent techniques, like polymerase chain reaction-temperature gradient gel electrophoresis, and construction of clone libraries of partial 16s rrna and nifh genes, to analyze the composition of the bacterial community in the rhizosphere of mature trees of eperua falcata and dicorynia guianensis, ...200717186143
cloning and characterization of the dxs gene, encoding 1-deoxy-d-xylulose 5-phosphate synthase from agrobacterium tumefaciens, and its overexpression in agrobacterium tumefaciens.a newly isolated gene dxs11 from agrobacterium tumefaciens (kccm 10413), an organism with potential for the industrial production of ubiquinone-10 (ubiq(10)), encoding a 1-deoxy-d-xylulose 5-phosphate synthase (dxs), was cloned in escherichia coli and its nucleotide sequence was determined. dna sequence analysis revealed an open reading frame of 1920bp, capable of encoding a polypeptide of 640 amino acids residues with a calculated isoelectric point of ph 5.63 and a molecular mass of 68,054da. t ...200717188774
genetic rearrangement of the atzab atrazine-degrading gene cassette from padp1::tn5 to the chromosome of variovorax sp. md1 and md2.we report the characterization of the rearrangement phenomena responsible for the movement of the atrazine-degrading atza and b genes from padp1::tn5 to the chromosome of variovorax sp. md1 and md2. long pcrs and southern blot analyses revealed that the two genes forming a gene cassette moved in a unique rearrangement event. it also revealed that the boundaries of the plasmid sequence inserted in the chromosome correspond to is1071or to sequences close to is1071. it suggests that this genetic re ...200717188820
occurrence and diversity of bacterial communities in tuber magnatum during truffle maturation.tuber magnatum, an ascomycetous fungus and obligate ectomycorrhizal symbiont, forms hypogeous fruit bodies, commonly called italian white truffles. the diversity of bacterial communities associated with t. magnatum truffles was investigated using culture-independent and -dependent 16s rrna gene-based approaches. eighteen truffles were classified in three groups, representing different degrees of ascocarp maturation, based on the percentage of asci containing mature spores. the culturable bacteri ...200717686021
orchid-associated bacteria produce indole-3-acetic acid, promote seed germination, and increase their microbial yield in response to exogenous auxin.germination of orchid seeds is a complex process. in this paper we focus on interactions between the host-plant and its bacterial partners via indole-3-acetic acid (iaa). originally isolated from the roots of the epiphytic orchid dendrobium moschatum, the strains of rhizobium, microbacterium, sphingomonas, and mycobacterium genera were among the most active iaa producers. addition of exogenous tryptophan significantly enhanced auxin formation both in mineral and complex media. the presence of ia ...200717687544
pgfpgusplus, a new binary vector for gene expression studies and optimising transformation systems in plants.a binary vector containing two reporter gene cassettes has been developed. this vector is ideal for optimising new plant transformation systems. following optimisation, one of the reporter genes can be replaced with a gene of interest; the second can be used as a marker to confirm transgenic lines, and to estimate locus number and determine zygosity. this allows simple, efficient and economical screening for homozygous single-insert lines and azygous controls.200717687623
homologous cpn60 genes in rhizobium leguminosarum are not functionally equivalent.many bacteria possess 2 or more genes for the chaperonin groel and the cochaperonin groes. in particular, rhizobial species often have multiple groel and groes genes, with a high degree of amino-acid similarity, in their genomes. the rhizobium leguminosarum strain a34 has 3 complete groe operons, which we have named cpn.1, cpn.2 and cpn.3. previously we have shown the cpn. 1 operon to be essential for growth, but the two other cpn operons to be dispensable. here, we have investigated the extent ...200717688191
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 ...200717690687
identification of a novel glyoxylate reductase supports phylogeny-based enzymatic substrate specificity prediction.phylogenetic analysis of the superfamily of d-2-hydroxyacid dehydrogenases identified the previously unrecognized cluster of glyoxylate/hydroxypyruvate reductases (ghpr). based on the genome sequence of rhizobium etli, the nodulating endosymbiont of the common bean plant, we predicted a putative 3-phosphoglycerate dehydrogenase to exhibit ghpr activity instead. the protein was overexpressed and purified. the enzyme is homodimeric under native conditions and is indeed capable of reducing both gly ...200717693143
diminished redundancy of outer membrane factor proteins in rhizobiales: a nodt homolog is essential for free-living rhizobium etli.rhizobium etli is a gram-negative soil bacterium that induces nitrogen-fixing nodules on common bean roots (phaseolus vulgaris). r. etli encodes two genes homologous to nodt of rhizobium leguminosarum. nodtch is chromosomal and forms an operon with new genes resembling a multi-drug efflux pump of the resistance-nodulation-cell division (rnd) family. nodtch is the last gene of this operon and can also be independently transcribed; the gene product is located in the bacterial outer membrane. cell ...200717693710
tyrosinase from rhizobium etli is involved in nodulation efficiency and symbiosis-associated stress resistance.tyrosinase (ec 1.14.18.1) is a monophenol oxidase responsible for the synthesis of the black pigment known as melanin. the tyrosinase gene (mela) is plasmid-encoded in many rhizobial species. in rhizobium etli cfn42, the genetic location of mela in the symbiotic plasmid (p42d) and its rpon-nifa regulation suggest an involvement in symbiosis. in this work, we analyzed the symbiotic phenotype of a streptomycin-resistant derivative of cfn42 (ce3), a mela mutant (sp2) and a complemented strain (sp66 ...200717693711
transgenic plants from shoot apical meristems of vitis vinifera l. "thompson seedless" via agrobacterium-mediated transformation.shoot apical meristem explants of vitis vinifera "thompson seedless" were used for agrobacterium-mediated genetic transformation. it was determined that the meristems had to be subjected to a dark growth phase then wounded to obtain transgenic plants. morphological and histological studies illustrated the role of wounding to expose apical meristem cells for transformation. a bifunctional egfp/nptii fusion gene was used to select kanamycin resistant plants that expressed green fluorescent protein ...200717701039
survival of bio-inoculants on fungicides-treated seeds of wheat, pea and chickpea and subsequent effect on chickpea yield.survival of mesorhizobium ciceri (sp(4)) and azotobacter chroococcum (cbd-15 and m(4)) was tested on chickpea (cicer arietinum) seeds treated with fungicides bavistin [methyl n-(1h-benzimidazol-2yl) carbamate] and thiram (tetramethyl-thiuram disulfide), whereas survival of phosphate solubilizing bacteria (psb), pseudomonas striata (27) and bacillus polymyxa (h(5)) was examined on two cultivars (arkel and bv) of pea (pisum sativum) seeds treated with thiram. viability of azotobacter chroococcum ( ...200717701702
yeast-plant coupled vector system for identification of nuclear proteins.nuclear proteins are involved in many critical biological processes within plant cells and, therefore, are in the focus of studies that usually begin with demonstrating that the protein of interest indeed exhibits nuclear localization. thus, studies of plant nuclear proteins would be facilitated by a convenient experimental system for identification of proteins that are actively imported into the cell nucleus and visualization of their nuclear accumulation in vivo. to this end, we developed a sy ...200717704231
recombinant synthesis of hyaluronan by agrobacterium sp.hyaluronan (ha) is a sugar polymer of a repeating disaccharide, beta1-3 d-n-acetylglucosamine (glcnac) beta1-4 d-glucuronic acid (glca). it finds applications in numerous biomedical procedures such as ophthalmic surgery and osteoarthritis treatment. until recently, the only commercial sources were extraction of rooster combs and from fermentation of pathogenic streptococcus. in this work, we demonstrate that metabolic engineering strategies enable the recombinant synthesis of hyaluronan in a saf ...200717705506
4-sulfomuconolactone hydrolases from hydrogenophaga intermedia s1 and agrobacterium radiobacter s2.the 4-carboxymethylen-4-sulfo-but-2-en-olide (4-sulfomuconolactone) hydrolases from hydrogenophaga intermedia strain s1 and agrobacterium radiobacter strain s2 are part of a modified protocatechuate pathway responsible for the degradation of 4-sulfocatechol. in both strains, the hydrolase-encoding genes occur downstream of those encoding the enzymes that catalyze the lactonization of 3-sulfomuconate. the deduced amino acid sequences of the 4-sulfomuconolactone hydrolases demonstrated the highest ...200717660282
identification of pti-sakura dna region conferring enhancement of plasmid incompatibility and stability.in agrobacterium tumefaciens, the stability of ti plasmids differs depending on the strain. so far, little is known about genes that cause the difference in stability. the repabc operon is responsible for replication and incompatibility of ti plasmids. we constructed recombinant plasmids carrying the repabc operon and different portions of pti-sakura. cells having the recombinant plasmids that harbored a 2.6-kbp nhei fragment of pti-sakura were found to be transformed via conjugation 100-fold le ...200717660690
stressed jerusalem artichoke tubers (helianthus tuberosus l.) excrete a protein fraction with specific cytotoxicity on plant and animal tumour cell.wounds from jerusalem artichoke (helianthus tuberosus l.) tubers excrete bioactive metabolites from a variety of structural classes, including proteins. here we describe a protein specifically active against tumour cells arising either from human, animal or plant tissues. the non-tumour animal cells or the plant callus cells are not sensitive to these excreta. the active product was only obtained after a wound-drought stress of plant tubers. the cytotoxicity varies according to the tumour cell t ...200717662535
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