Publications

symbiosis. fast friends, sworn enemies.		2003	14593147
increased synthesis of dihydroxybenzoic acid in the presence of aluminum by rhizobium mo1.	rhizobizum sp. mo1, a mung bean (vigna radiata) symbiont, produces a catecholate type of siderophore, 2,3-dihydroxy benzoic acid (dhba), in iron depleted medium. addition of aluminum to the medium decreased the growth but increased the production of the siderophore.	2003	14594407
factors influencing agrobacterium-mediated embryogenic callus transformation of valencia sweet orange (citrus sinensis) containing the pta29-barnase gene.	valencia sweet orange (citrus sinensis (l.) osbeck) calluses were used as explants to develop a new transformation system for citrus mediated by agrobacterium tumefaciens. factors affecting agrobacterium-mediated transformation efficiency included mode of pre-cultivation, temperature of cocultivation and presence of acetosyringone (as). the highest transformation efficiency was obtained with a 4-day pre-cultivation period in liquid medium. transformation efficiency was higher when cocultivation ...	2003	14597430
characterization of a soil-derived bacterial consortium degrading 4-chloroaniline.	a bacterial consortium comprising four different species was isolated from an indonesian agricultural soil using a mixture of aniline and 4-chloroaniline (4ca) as principal carbon sources. the four species were identified as chryseobacterium indologenes sb1, comamonas testosteroni sb2, pseudomonas corrugata sb4 and stenotrophomonas maltophilia sb5. growth studies on aniline and 4ca as single and mixed substrates demonstrated that the bacteria preferred to grow on and utilize aniline rather than ...	2003	14600240
glycolytic breakdown of sulfoquinovose in bacteria: a missing link in the sulfur cycle.	sulfoquinovose (6-deoxy-6-sulfo-d-glucopyranose), formed by the hydrolysis of the plant sulfolipid, is a major component of the biological sulfur cycle. however, pathways for its catabolism are poorly delineated. we examined the hypothesis that mineralization of sulfoquinovose to inorganic sulfate is initiated by reactions of the glycolytic and/or entner-doudoroff pathways in bacteria. metabolites of [u-(13)c]sulfoquinovose were identified by (13)c-nuclear magnetic resonance (nmr) in strains of ...	2003	14602597
plant transformation by coinoculation with a disarmed agrobacterium tumefaciens strain and an escherichia coli strain carrying mobilizable transgenes.	transformation of nicotiana tabacum leaf explants was attempted with escherichia coli as a dna donor either alone or in combination with agrobacterium tumefaciens. we constructed e. coli donor strains harboring either the promiscuous incp-type or incn-type conjugal transfer system and second plasmids containing the respective origins of transfer and plant-selectable markers. neither of these conjugation systems was able to stably transform plant cells at detectable levels, even when vire2 was ex ...	2003	14602634
agrobacterium bioassay strain for ultrasensitive detection of n-acylhomoserine lactone-type quorum-sensing molecules: detection of autoinducers in mesorhizobium huakuii.	an ultrasensitive bioassay system for the detection of n-acylhomoserine lactones (ahls) was constructed in agrobacterium tumefaciens by using the t7 expression system to overproduce the ahl receptor trar. this strain detected many diverse ahls, some at extremely low concentrations. we used this strain to detect for the first time ahls made by mesorhizobium huakuii, which symbiotically fixes nitrogen in association with the legume astragalus sinicus, a source of green manure throughout eastern as ...	2003	14602662
diphtheria toxin-mediated cell ablation reveals interregional communication during arabidopsis seed development.	fertilization of the female gametophyte in angiosperm plants initiates a process of coordinated development of embryo, endosperm, and seed coat that ensures the production of a viable seed. mutant analysis has suggested that communication between the endosperm and the seed coat is an important determinant in this process. in addition, cell groups within the embryo, derived from the apical and from the basal cell, respectively, after zygote division, concertedly establish a functional root merist ...	2003	14605218
endophytic nifh gene diversity in african sweet potato.	a cultivation-independent approach was used to identify potentially nitrogen-fixing endophytes in seven sweet potato varieties collected in uganda and kenya. nitrogenase reductase genes (nifh) were amplified by pcr, and amplicons were cloned in escherichia coli. clones were grouped by restriction fragment length polymorphism analysis, and representative nifh genes were sequenced. the resulting sequences had high homologies to nitrogenase reductases from alpha-, beta-, and gamma-proteobacteria an ...	2003	14608421
comparative expression analysis of two sugarcane polyubiquitin promoters and flanking sequences in transgenic plants.	gus (uida) reporter gene expression for two sugarcane polyubiquitin promoters, ubi4 and ubi9, was compared to expression from the maize ubi-1 promoter in stable transgenic rice (only ubi9) and sugarcane (ubi4 and ubi9). ubi9 drove high-level gus expression, comparable to the maize ubi-1 promoter, in both callus and regenerated plants of rice transformed by agrobacterium. this high level expression was inherited in r1 plants. expression from ubi4 and ubi9 was quite high in sugarcane callus transf ...	2003	14610893
efficient and genotype-independent agrobacterium--mediated tomato transformation.	an efficient method to transform five cultivars of tomato (lycopersicon esculentum), micro-tom, red cherry, rubion, piedmont, and e6203 is reported. a comparison was made of leaf, cotyledon, and hypocotyl explants on 7 different regeneration media without agrobacterium tumefaciens cocultivation and on 11 different media with cocultivation. although all cultivars and explants formed callus and regenerated on the initial 7 media, cocultivation with a. tumefaciens significantly reduced the callus i ...	2003	14610894
the agrobacterium-plant cell interaction. taking biology lessons from a bug.		2003	14612580
agrobacterium tumefaciens and the plant: the david and goliath of modern genetics.		2003	14612581
agrobacterium-mediated root transformation is inhibited by mutation of an arabidopsis cellulose synthase-like gene.	agrobacterium-mediated plant genetic transformation involves a complex interaction between the bacterium and the host plant. relatively little is known about the role plant genes and proteins play in this process. we previously identified an arabidopsis mutant, rat4, that is resistant to agrobacterium transformation. we show here that rat4 contains a t-dna insertion into the 3'-untranslated region of the cellulose synthase-like gene csla9. csla9 transcripts are greatly reduced in the rat4 mutant ...	2003	14612582
[regulation to curd morphogenesis and genetics of exogenous bocal gene in cauliflower].	cauliflower (brassica oleracea var. botrytis l.) and cabbage (b. oleracea var capitata l.) are two varieties of species b. oleracea. cauliflower bobcal gene losses the original function due to its terminated mutation while cabbage bocal gene has the complete function. we obtained cauliflower plants transgenic for bocal gene using arobacterium-mediated transformation. genetic analysis of t2 generation indicated that all cauliflower plants transgenic for bocal failed to form curd and produced the ...	2003	14574987
[a simple and highly efficient agrobacterium-mediated rice transformation system].	a simple and highly efficient rice transformation system was established based on the studying of factors influencing the agrobacterium-mediated rice transformation. embryogenic calli derived from mature embryos were infected and cocultivated with a. tumefaciens eha101 harboring binary vectors: phq9, phq10, phqt3. the highest transformation frequency was about 100 hygromycin resistance calli per gram of calli explants, and above 85% of these calli could be regenerated into plants. the putative t ...	2003	14574993
[changes and distribution of atpase activity in the paranodules of nicotiana tabacum].	lead phosphate deposition technique was used to investigate the changes and characteristic distribution of atpase activity in the paranodules of tabacoo. we found that atpase activity was closely associated with cell type and cell developmental state, thus it was different in various cells and rhizobia. no lead phosphate granules were located in the menstematic cells, although there were a small number of lead phosphate granules in the cytoplasm and organelles of the cells without rhizobia, they ...	2003	14574995
plant sciences. how legumes select their sweet talking symbionts.		2003	14576408
three-dimensional reconstruction of tubular structure of vacuolar membrane throughout mitosis in living tobacco cells.	plant vacuoles are the largest of organelles, performing various functions in cellular metabolism, morphogenesis and cell division. dynamic changes in vacuoles during mitosis were studied by monitoring tubular structure of vacuolar membrane (tvm) in living transgenic tobacco by-2 cells stably expressing a gfp-atvam3p fusion protein (by-gv). comprehensive images of the complicated tvm configurations were obtained by reconstructing three-dimensional (3-d) surface structures from sequential confoca ...	2003	14581629
isolation and characterization of sulfur-utilizing denitrifiers from the sulfur-oxidizing denitrification process.	of 14 potential sulfur-oxidizing strains, pseudomonas sp. b21 and agrobacterium sp. b19 were considered as denitrifiers. under aerobic conditions, with s0 as electron donor, maximum cell growth rates were 0.022 (b21) and 0.043 h(-1) (b19). both grew optimally at ph 7.5 and 28 degrees c. when no3-n was increased from 10 to 200 mg l(-1) the efficiency of nitrate removal of each strain gradually decreased, from 60 to 40%. addition of suitable organic compounds (c/n < 4.2) increased the nitrate remo ...	2003	14584914
expression and production of bioactive human interleukin-18 in transgenic tobacco plants.	the cdna of human interleukin-18 (hil-18) was successfully inserted into the genome of tobacco plant, nicotiana tabacum cv. nc-89, using agrobacterium tumefaciens-mediated transformation. insertion and translation of hil-18 in transformants were confirmed by pcr, elisa, and western blot, respectively. the transformed extracts contained the recombinant hil-18 protein up to 0.05% of total soluble protein. activity of the recombinant hil-18 in plant cells was confirmed by the induction of ifn-gamma ...	2003	14584919
development of a novel agrobacterium-mediated transformation method to recover transgenic brassica napus plants.	we report here an in planta method to produce transgenic brassica napus plants. the procedure included agrobacterium-mediated inoculation of plants at various development stages along with a vacuum infiltration step. the flowering stage appeared to be the most receptive stage for transformation and production of transgenic plants. in some cases, the flowering stage was induced either by cold treatment or by high density planting. molecular and genetic analysis revealed that single and multiple c ...	2003	14586552
[transformation of bar gene to tetraploid of isatis indigotica].	the transgenic tetraploid of isatis indigotica mediated by agrobacterium tumefaciens was obtained. to transfer the plant binary expression vector pcambia 3300 carrying bar gene, the agrobacterium tumefaciens strain eha 105 was used as engineering bacterium. the results of pcr indicated that the bar gene had been transferred into and merged with the genome of isatis indigotica. this study will make foundation for improvement of other characters of this species with genetic engineering.	2003	14535009
transcriptome analysis of arabidopsis colonized by a plant-growth promoting rhizobacterium reveals a general effect on disease resistance.	rna transcript levels of arabidopsis plants, infected by the rhizobacterium pseudomonas thivervalensis (strain mlg45), and axenic control plants were compared using cdna microarrays representing approximately 14 300 genes. the analysis revealed an increase of defence-related transcripts in the shoots of bacterized plants relative to control (axenic) plants. these modifications of transcript levels were confirmed by physiological experiments. plants infected with p. thivervalensis were more resis ...	2003	14535883
genetic locus and structural characterization of the biochemical defect in the o-antigenic polysaccharide of the symbiotically deficient rhizobium etli mutant, ce166. replacement of n-acetylquinovosamine with its hexosyl-4-ulose precursor.	the o-antigen polysaccharide (ops) of rhizobium etli ce3 lipopolysaccharide (lps) is linked to the core oligosaccharide via an n-acetylquinovosaminosyl (quinac) residue. a mutant of ce3, ce166, produces lps with reduced amounts of ops, and a suppressed mutant, ce166 alpha, produces lps with nearly normal ops levels. both mutants are deficient in quinac production. characterization of ops from ce166 and ce166 alpha showed that quinac was replaced by its 4-keto derivative, 2-acetamido-2,6-dideoxyh ...	2003	14551189
site-specific integration of agrobacterium tumefaciens t-dna via double-stranded intermediates.	agrobacterium tumefaciens-mediated genetic transformation involves transfer of a single-stranded t-dna molecule (t strand) into the host cell, followed by its integration into the plant genome. the molecular mechanism of t-dna integration, the culmination point of the entire transformation process, remains largely obscure. here, we studied the roles of double-stranded breaks (dsbs) and double-stranded t-dna intermediates in the integration process. we produced transgenic tobacco (nicotiana tabac ...	2003	14551323
reexamining the role of the accessory plasmid patc58 in the virulence of agrobacterium tumefaciens strain c58.	isogenic strains of agrobacterium tumefaciens carrying ptic58, patc58, or both were constructed and assayed semiquantitatively and quantitatively for virulence and vir gene expression to study the effect of the large 542-kb accessory plasmid, patc58, on virulence. earlier studies indicate that the att (attachment) genes of a. tumefaciens are crucial in the ability of this soil phytopathogen to infect susceptible host plants. mutations in many att genes, notably attr and attd, rendered the strain ...	2003	14551325
recognition of the agrobacterium tumefaciens vire2 translocation signal by the virb/d4 transport system does not require vire1.	agrobacterium tumefaciens uses a type iv secretion system to deliver a nucleoprotein complex and effector proteins directly into plant cells. the single-stranded dna-binding protein vire2, the f-box protein virf and vire3 are delivered into host cells via this virb/d4 encoded translocation system. vire1 functions as a chaperone of vire2 by regulating its efficient translation and preventing vire2-vire2 aggregation in the bacterial cell. we analyzed whether the vire1 chaperone is also essential f ...	2003	14551327
targeted integration of t-dna into the tobacco genome at double-stranded breaks: new insights on the mechanism of t-dna integration.	agrobacterium tumefaciens t-dna normally integrates into random sites in the plant genome. we have investigated targeting of t-dna by nonhomologous end joining process to a specific double-stranded break created in the plant genome by i-ceui endonuclease. sequencing of genomic dna/t-dna junctions in targeted events revealed that genomic dna at the cleavage sites was usually intact or nearly so, whereas donor t-dna ends were often resected, sometimes extensively, as is found in random t-dna inser ...	2003	14551336
peritonitis caused by agrobacterium tumefaciens in a child on peritoneal dialysis.		2003	14551394
identical accumulation and immobilization of sulfated and nonsulfated nod factors in host and nonhost root hair cell walls.	nod factors are signaling molecules secreted by rhizobium bacteria. these lipo-chitooligosaccharides (lcos) are required for symbiosis with legumes and can elicit specific responses at subnanomolar concentrations on a compatible host. how plants perceive lcos is unclear. in this study, using fluorescent nod factor analogs, we investigated whether sulfated and nonsulfated nod factors were bound and perceived differently by medicago truncatula and vicia sativa root hairs. the bioactivity of three ...	2003	14558690
symbiotic n2 fixation activity in relation to c economy of pisum sativum l. as a function of plant phenology.	the relationships between symbiotic nitrogen fixation (snf) activity and c fluxes were investigated in pea plants (pisum sativum l. cv. baccara) using simultaneous 13c and 15n labelling. analysis of the dynamics of labelled co2 efflux from the nodulated roots allowed the different components associated with snf activity to be calculated, together with root and nodule synthetic and maintenance processes. the carbon costs for the synthesis of roots and nodules were similar and decreased with time. ...	2003	14563833
effects of gypsophila saponins on bacterial growth kinetics and on selection of subterranean clover rhizosphere bacteria.	plant secondary metabolites, such as saponins, have a considerable impact in agriculture because of their allelopathic effects. they also affect the growth of soil microorganisms, especially fungi. we investigated the influence of saponins on rhizosphere bacteria in vitro and in soil conditions. the effects of gypsophila saponins on the growth kinetics of rhizosphere bacteria were studied by monitoring the absorbance of the cultures in microtiter plates. gypsophila saponins (1%) increased the la ...	2003	14569290
a calcium-dependent bacterial surface protein is involved in the attachment of rhizobia to peanut roots.	as part of a project to characterize molecules involved in the crack-entry infection process leading to nodule development, a microscopic assay was used to visualize the attachment of cells of bradyrhizobium sp. strains semia 6144 and tal 1000 (labelled by introducing a plasmid expressing constitutively the green fluorescent protein gfp-s65t) to arachis hypogaea l. (peanut). qualitative and quantitative results revealed that attachment was strongly dependent on the growth phase of the bacteria. ...	2003	14569294
solubility enhancement of a hydrophobic flavonoid, luteolin by the complexation with cyclosophoraoses isolated from rhizobium meliloti.	a plant flavone, luteolin is a well-known inducer of nod genes in the rhizobium meliloti. its poor aqueous solubility was greatly enhanced by the complexation with a family of cyclosophoraoses synthesized in r.meliloti. nuclear magnetic resonance (nmr) spectroscopic analysis showed that the chemical shifts of the aromatic ring moieties of the luteolin were changed greatly by the complexation with cyclosophoraoses. fourier transform infrared (ftir) spectroscopic analysis also showed a restricted ...	2003	14574115
polyphasic taxonomy of symbiotic rhizobia from wild leguminous plants growing in egypt.	about 20 strains of rhizobia from wild legumes were characterized based on numerical analysis of phenotypic characteristics, nodulating ability, fatty acid methyl esters (fame) and sds-page profiles of whole cell proteins. fame analysis revealed that palmitic (16:0), stearic (18:0) and arachidonic (20:0) were detected in most of wild-legume rhizobia, the latter being uncommon in fatty acid profiles of rhizobium and sinorhizobium. numerical analysis of fame classified strains of wild-legume rhizo ...	2003	14533483
low sequence similarity and gene content of symbiotic clusters of bradyrhizobium sp. wm9 (lupinus) indicate early divergence of "lupin" lineage in the genus bradyrhizobium.	two sequenced nodulation regions of lupin bradyrhizobium sp. wm9 carried the majority of genes involved in the nod factor production. the nod region i harbored: nola, nodd, noda, nodb, nodc, nods, nodi, nodj, nolo, nodz, fixr, nifa, fixa, nodm, nolk and noel. this gene arrangement resembled that found in the nodulation region of bradyrhizobium japonicum usda110, however strain wm9 harbored only one nodd gene copy, while the nodm, nolk and noel genes had no counterparts in the 410 kb symbiotic re ...	2003	14533715
plant biology: locks, keys and symbioses.		2003	14534570
plant recognition of symbiotic bacteria requires two lysm receptor-like kinases.	although most higher plants establish a symbiosis with arbuscular mycorrhizal fungi, symbiotic nitrogen fixation with rhizobia is a salient feature of legumes. despite this host range difference, mycorrhizal and rhizobial invasion shares a common plant-specified genetic programme controlling the early host interaction. one feature distinguishing legumes is their ability to perceive rhizobial-specific signal molecules. we describe here two lysm-type serine/threonine receptor kinase genes, nfr1 an ...	2003	14534578
a receptor kinase gene of the lysm type is involved in legume perception of rhizobial signals.	plants belonging to the legume family develop nitrogen-fixing root nodules in symbiosis with bacteria commonly known as rhizobia. the legume host encodes all of the functions necessary to build the specialized symbiotic organ, the nodule, but the process is elicited by the bacteria. molecular communication initiates the interaction, and signals, usually flavones, secreted by the legume root induce the bacteria to produce a lipochitin-oligosaccharide signal molecule (nod-factor), which in turn tr ...	2003	14534591
t-dna mutagenesis in arabidopsis.	insertional mutagenesis is a basic genetic tool that allows for a rapid identification of the tagged genes responsible for a particular phenotype. transposon and agrobacterium-mediated dna integration are the most commonly used biological mutagens in plants. the main drawback of these technologies is the relatively low frequency of mutations, as compared to those induced by conventional chemical or physical agents, thus limiting the use of insertional mutagens to the generation of large mutant p ...	2003	14501065
virus-induced gene silencing.	in the postgenomic era, large-scale functional genomic approaches are necessary for converting sequence information into functional information. a para-genetic approach, called virus-induced gene silencing (vigs), offers a rapid means of gaining insight into gene function in plants. vigs system could be used to suppress endogenous gene expression by infecting plants with a recombinant virus vector (vigs vector) carrying host-derived sequence. here, we describe the use of tobacco rattle virus (tr ...	2003	14501071
maintaining collections of mutants for plant functional genomics.	as the plant genomics era progresses and post-genomic functional research rapidly expands, varied genetic resources of unprecedented power and scope are being developed. partially by the mandate of public funding, these resources are being shared via stock centers and private laboratories. the successful initiation of any new research requires that advantage be taken of these stocks. information on most plant genomic resources can be obtained through simple yet powerful. web searches, and orderi ...	2003	14501073
t-dna activation tagging.	t-dna activation tagging is a method to generate dominant mutations in plants or plant cells by random insertion of a t-dna carrying constitutive enhancer elements, which can cause transcriptional activation of flanking plant genes. the method consists of generating a large number of transformed plants or plant cells using a specialized t-dna construct, followed by selection for the desired phenotype. subsequently, the activated plant gene is rescued from selected mutant transformants for furthe ...	2003	14501075
production of herbicide-tolerant zoysiagrass by agrobacterium-mediated transformation.	herbicide-resistant zoysiagrass (zoysia japonica steud.) has been developed by agrobacterium-mediated transformation. a callus-type transformation system was established by optimizing several factors that affect the rate of transformation, including co-cultivation period and concentrations of 2,4-dichlorophenoxyacetic acid (2,4-d), cacl2 and acetosyringone. maximal gus expression was observed when a type 3 callus was co-cultivated on 2,4-d-free co-cultivation medium for 9 d. in addition, removal ...	2003	14503840
nodd alleles of sinorhizobium fredii usda191 differentially influence soybean nodulation, nodc expression, and production of exopolysaccharides.	all rhizobium strains examined to date have one or multiple alleles of nodd. at least one copy of nodd and the presence of flavonoid exudates are required for nod gene induction and nodulation. sinorhizobium fredii usda191 has two copies of nodd. in this study, we demonstrate that inactivation of either copy of nodd caused a reduction in basal levels of expression of nodc. extra copies of nodd1 had no effect on the expression of nodc when compared with the wild type, but extra copies of nodd2 ab ...	2003	14506861
transgenic rose lines harboring an antimicrobial protein gene, ace-amp1, demonstrate enhanced resistance to powdery mildew ( sphaerotheca pannosa).	an antimicrobial protein gene, ace-amp1, was introduced into rosa hybrida cv. carefree beauty via agrobacterium-mediated transformation. a total of 500 putative transgenic plants were obtained from 100 primary embryogenic calli co-cultivated with a. tumefaciens following selection on a regeneration medium containing 100 mg/l kanamycin. polymerase chain reaction analysis of these putative transgenic lines, using primers for both ace-amp1 and neomycin phosphotransferase ( npt ii) genes, showed tha ...	2003	14508687
temporal change in culturable phenanthrene degraders in response to long-term exposure to phenanthrene in a soil column system.	widespread environmental contamination by polycyclic aromatic hydrocarbons (pah) has led to increased interest in the use of natural attenuation as a clean-up strategy. however, few bioremediation studies have investigated the behaviour of the indigenous pah-degrading community after long-term exposure to a pah. in this study, a column packed with sandy loam soil was exposed to a solution saturated with phenanthrene ( approximately 1.2 mg l-1) for a 6-month period to examine the temporal respons ...	2003	14510842
effect of thorium on the growth and capsule morphology of bradyrhizobium.	the thorium effect on bradyrhizobium growth was assayed in liquid media. th4+ inhibited the growth of bradyrhizobium (chamaecytisus) bga-1, but this effect decreased in the presence of suspensions of live or dead bacterial cells. th4+ induced the formation of a gel-like precipitate when added to a dense suspension of b. (chamaecytisus) bga-1 cells. viable bradyrhizobium cells remained in suspension after precipitate formation. thorium was recovered in the precipitate, in which polysaccharide, li ...	2003	14510845
an improved protocol for agrobacterium-mediated transformation of antirrhinum majus l.	efficient agrobacterium -mediated transformation of antirrhinum majus l. was achieved via indirect shoot organogenesis from hypocotyl explants of seedlings. stable transformants were obtained by inoculating explants with a. tumefaciens strain gv2260 harboring the binary vector pbigfp121, which contains the neomycin phosphotransferase gene ( npt ii) as a selectable marker and the gene for the green fluorescent protein ( gfp) as a visual marker. putative transformants were identified by selection ...	2003	14513365
screening, identification and kinetic characterization of a bacterium for mn(ii) uptake and oxidation.	following sample collection and screening at a number of mn-associated mine sites in northern australia, a microbial strain was selected for its enhanced rate of mn uptake. the strain was identified by phylogenetic analysis as a rhizobium sp. kinetic studies of mn(ii) uptake and oxidation by this strain in glucose-based media established that the uptake of mn(ii) was much greater than the conversion of mn(ii) to mn oxide. chemical analysis and scanning electron microscopy confirmed the productio ...	2003	14514041
anions effects on biosorption of mn(ii) by extracellular polymeric substance (eps) from rhizobium etli.	microbial extracellular polymeric substances (eps) are potential biosorbents for metal remediation and recovery. the langmuir and freundlich kinetics of mn(ii) binding by the eps from a novel mn(ii) oxidising strain of rhizobium etli were determined. maximum manganese specific adsorptions (q(max)) decreased in the sequence: sulphate (62 mg mn per g eps) > nitrate (53 mg g(-1)) > chloride (21 mg g(-1)). consideration of the anion during kinetic studies is usually neglected but is important in pro ...	2003	14514079
structure and mechanism of a bacterial haloalcohol dehalogenase: a new variation of the short-chain dehydrogenase/reductase fold without an nad(p)h binding site.	haloalcohol dehalogenases are bacterial enzymes that catalyze the cofactor-independent dehalogenation of vicinal haloalcohols such as the genotoxic environmental pollutant 1,3-dichloro-2-propanol, thereby producing an epoxide, a chloride ion and a proton. here we present x-ray structures of the haloalcohol dehalogenase hhec from agrobacterium radiobacter ad1, and complexes of the enzyme with an epoxide product and chloride ion, and with a bound haloalcohol substrate mimic. these structures suppo ...	2003	14517233
physical and gene maps of agrobacterium biovar 2 strains and their relationship to biovar 1 chromosomes.	diverse types of genomic dna organization have been found in rhizobiaceae, especially among agrobacterium species. previous studies of agrobacterium concentrated mainly on biovar 1 strains. little attention has been given to biovar 2 strains. the biovar 2 genome consists of a large, circular chromosome and second megabase-sized replicon, as well as several plasmids. in this study two biovar 2 strains were analysed, a. rhizogenes (a. radiobacter) k84 and a. rhizogenes a4, by constructing physical ...	2003	14523134
flavonoid-related regulation of auxin accumulation in agrobacterium tumefaciens-induced plant tumors.	agrobacterium tumefaciens-induced plant tumors accumulate considerable concentrations of free auxin. to determine possible mechanisms by which high auxin concentrations are maintained, we examined the pattern of auxin and flavonoid distribution in plant tumors. tumors were induced in transformants of trifolium repens (l.), containing the beta-glucuronidase ( gus)-fused auxin-responsive promoter ( gh3) or chalcone synthase ( chs2) genes, and in transformants of arabidopsis thaliana (l.) heynh., c ...	2003	14523649
nucleotide-dependent conformational changes in the sigma54-dependent activator dctd.	activators of sigma(54)-rna polymerase holoenzyme couple atp hydrolysis to formation of an open promoter complex. dctd(delta1-142), a truncated and constitutively active form of the sigma(54)-dependent activator dctd from sinorhizobium meliloti, displayed an altered dnase i footprint at its binding site located upstream of the dcta promoter in the presence of atp. the altered footprint was not observed for a mutant protein with a substitution at or near the putative arginine finger, a conserved ...	2003	14526036
vascularization, high-volume solution flow, and localized roles for enzymes of sucrose metabolism during tumorigenesis by agrobacterium tumefaciens.	vascular differentiation and epidermal disruption are associated with establishment of tumors induced by agrobacterium tumefaciens. here, we address the relationship of these processes to the redirection of nutrient-bearing water flow and carbohydrate delivery for tumor growth within the castor bean (ricinus communis) host. treatment with aminoethoxyvinyl-glycine showed that vascular differentiation and epidermal disruption were central to ethylene-dependent tumor establishment. co2 release para ...	2003	14526106
a catalogue of molecular, physiological and symbiotic properties of soybean-nodulating rhizobial strains from different soybean cropping areas of china.	we have analysed 198 fast-growing soybean-nodulating rhizobial strains from four different regions of china for the following characteristics: generation time; number of plasmids; lipopolysaccharide (lps), nodulation factors (lcos) and pcr profiles; acidification of growth medium; capacity to grow at acid, neutral, and alkaline ph; growth on lc medium; growth at 28 and 37 degrees c; melanin production capacity; congo red absorption and symbiotic characteristics. these unbiased analyses of a tota ...	2003	14529189
combinatorial modification of multiple lignin traits in trees through multigene cotransformation.	lignin quantity and reactivity [which is associated with its syringyl/guaiacyl (s/g) constituent ratio] are two major barriers to wood-pulp production. to verify our contention that these traits are regulated by distinct monolignol biosynthesis genes, encoding 4-coumarate-coa ligase (4cl) and coniferaldehyde 5-hydroxylase (cald5h), we used agrobacterium to cotransfer antisense 4cl and sense cald5h genes into aspen (populus tremuloides). trees expressing each one and both of the transgenes were p ...	2003	12668766
membrane topology of psst, the transmembrane protein component of the type i exopolysaccharide transport system in rhizobium leguminosarum bv. trifolii strain ta1.	the psst gene was identified as the fourth gene located upstream of the pssnop gene cluster possibly involved in the biosynthesis, polymerization, and transport of exopolysaccharide (eps) in rhizobium leguminosarum bv. trifolii strain ta1. the hydropathy profile and homology searches indicated that psst belongs to the polysaccharide-specific transport family of proteins, a component of the type i system of the polysaccharide transport. the predicted membrane topology of the psst protein was exam ...	2003	12670974
identification of a third sulfate activation system in sinorhizobium sp. strain br816: the cysdn sulfate activation complex.	sinorhizobium sp. strain br816 possesses two nodpq copies, providing activated sulfate (3'-phosphoadenosine-5'-phosphosulfate [paps]) needed for the biosynthesis of sulfated nod factors. it was previously shown that the nod factors synthesized by a nodpq double mutant are not structurally different from those of the wild-type strain. in this study, we describe the characterization of a third sulfate activation locus. two open reading frames were fully characterized and displayed the highest simi ...	2003	12676676
compatibility of rhizobial genotypes within natural populations of rhizobium leguminosarum biovar viciae for nodulation of host legumes.	populations of rhizobium leguminosarum biovar viciae were sampled from two bulk soils, rhizosphere, and nodules of host legumes, fava bean (vicia faba) and pea (pisum sativum) grown in the same soils. additional populations nodulating peas, fava beans, and vetches (vicia sativa) grown in other soils and fava bean-nodulating strains from various geographic sites were also analyzed. the rhizobia were characterized by repetitive extragenomic palindromic-pcr fingerprinting and/or pcr-restriction fra ...	2003	12676710
evolution of an organophosphate-degrading enzyme: a comparison of natural and directed evolution.	organophosphate-degrading enzyme from agrobacterium radiobacter p230 (opda) is a recently discovered enzyme that degrades a broad range of organophosphates. it is very similar to oph first isolated from pseudomonas diminuta mg. despite a high level of sequence identity, oph and opda exhibit different substrate specificities. we report here the structure of opda and identify regions of the protein that are likely to give it a preference for substrates that have shorter alkyl substituents. directe ...	2003	12676982
highly efficient production and characterization of t-dna plants for rice ( oryza sativa l.) functional genomics.	we investigated the potential of an improved agrobacterium tumefaciens-mediated transformation procedure of japonica rice ( oryza sativa l.) for generating large numbers of t-dna plants that are required for functional analysis of this model genome. using a t-dna construct bearing the hygromycin resistance ( hpt), green fluorescent protein ( gfp) and beta-glucuronidase ( gusa) genes, each individually driven by a camv 35s promoter, we established a highly efficient seed-embryo callus transformat ...	2003	12677401
molecular cloning and characterization of triterpene synthases from medicago truncatula and lotus japonicus.	cloning of oscs required for triterpene synthesis from legume species that are amenable to molecular genetics will provide tools to address the importance of triterpenes and their derivatives during normal plant growth and development and also in interactions with symbionts and pathogens. here we report the cloning and characterization of a total of three triterpene synthases from the legume species medicago truncatula and lotus japonicus. these include a beta-amyrin synthase from m. truncatula ...	2003	12683345
the mode of action of cell wall-degrading enzymes and their interference with nod factor signalling in medicago sativa root hairs.	medicago sativa l. (alfalfa) root hairs respond to nod factors [nodrm-iv(c16:2,s)] in a host-specific manner with depolarization and rapid ion fluxes. protoplasts prepared from these cells using the cell wall-digesting enzymes pectolyase and cellulase do not, or to a rather small extent, respond to nod factors. in an effort to understand this activity loss we analyzed the mode of action of both enzymes with respect to their effects on the root hairs as well as their interference with the nod fac ...	2003	12687367
effect of cadmium on nodulation and n2-fixation of soybean in contaminated soils.	the effects of cadmium stress on nodulation, n2-fixation capabilities of the root nodule, the change in ultrastructure of the root nodule, soybean growth, and the distribution of cadmium in plants were studied. the results obtained show that the nodulation of soybean roots was greatly inhibited by the addition of cd, especially at the addition level of 10 and 20 mg kg(-1) soil. the inhibition of plant growth, especially the root growth, increased as the cadmium concentration increased, with dele ...	2003	12688491
in situ activation of the quorum-sensing transcription factor trar by cognate and noncognate acyl-homoserine lactone ligands: kinetics and consequences.	conjugal transfer of ti plasmids of agrobacterium tumefaciens is controlled by a quorum-sensing system composed of the transcriptional activator trar and its acyl-homoserine lactone quormone n-(3-oxo-octanoyl)-l-homoserine lactone (3-oxo-c8-hsl). the population density dependence of quorum-sensing systems can often be circumvented by addition of the quormone to cultures at low cell numbers. however, the quorum-dependent activation of ti plasmid conjugal transfer exhibited a lag of almost 8 h whe ...	2003	13129937
characterization of rhizobia isolated from legume species within the genera astragalus and lespedeza grown in the loess plateau of china and description of rhizobium loessense sp. nov.	twenty-nine rhizobial isolates from root nodules of astragalus and lespedeza spp. growing in the loess plateau of china were characterized by numerical taxonomy, rflp and sequencing of pcr-amplified 16s rrna genes, measurement of dna g+c content, dna-dna relatedness and cross-nodulation with selected legume species. based on the results of numerical taxonomy, the isolates formed two clusters (1 and 2) with some single isolates at a similarity level of 82 %. cluster 1 contained six isolates from ...	2003	13130051
agrobacterium is a definable genus of the family rhizobiaceae.	members of the genus agrobacterium constitute a diverse group of organisms, all of which, when harbouring the appropriate plasmids, are capable of causing neoplastic growths on susceptible host plants. the agrobacteria, which are members of the family rhizobiaceae, can be differentiated into at least three biovars, corresponding to species divisions based on differential biochemical and physiological tests. recently, young et al. [int j syst evol microbiol 51 (2003), 89-103] proposed to incorpor ...	2003	13130068
classification and nomenclature of agrobacterium and rhizobium.	farrand et al. [int j syst evol microbiol 53 (2003), 1681-1687] have presented a critique of the proposal of young et al. [int j syst evol microbiol 51 (2001), 89-103] to revise the nomenclature and classification of rhizobium: they argued that young et al. (2001) are mistaken in their reclassification of all agrobacterium species within rhizobium, and that the resulting nomenclatural revision is 'unnecessary and unwarranted'. these objections arise because the authors appear not to understand t ...	2003	13130069
rhizobium (agrobacterium) radiobacter identified as a cause of chronic endophthalmitis subsequent to cataract extraction.	herein, we report a case of chronic endophthalmitis caused by a ceftazidime-resistant rhizobium radiobacter strain in a 62-year-old male. the patient underwent an uneventful cataract extraction of the right eye a week prior to the appearance of symptoms (pain, redness, and blurring vision) which developed following a golf outing. upon admission the patient received an emergency vitrectomy. the patient remained symptomatic, and r. radiobacter was isolated repeatedly from vitreous fluid cultures o ...	2003	12904441
novel bacteria degrading n-acylhomoserine lactones and their use as quenchers of quorum-sensing-regulated functions of plant-pathogenic bacteria.	bacteria degrading the quorum-sensing (qs) signal molecule n-hexanoylhomoserine lactone were isolated from a tobacco rhizosphere. twenty-five isolates degrading this homoserine lactone fell into six groups according to their genomic rep-pcr and rrs pcr-rflp profiles. representative strains from each group were identified as members of the genera pseudomonas, comamonas, variovorax and rhodococcus: all these isolates degraded n-acylhomoserine lactones other than the hexanoic acid derivative, albei ...	2003	12904538
genetic transformation of the figwort, scrophularia buergeriana miq., an oriental medicinal plant.	scrophularia buergeriana miq. (figwort) contains a diverse group of bioactive natural products and is used to treat a variety of ailments, including fever, constipation, neuritis, and laryngitis. a transformation protocol was established for s. buergeriana using agrobacterium tumefaciens. kanamycin-resistant plants were regenerated from leaf explants co-cultivated with a. tumefaciens strain gv3101. the shoot regeneration medium was supplemented with 2 mg l(-1) 6-benzylaminopurine and 70 mg l(-1) ...	2003	12910369
stable transformants of the azaphilone pigment-producing monascus purpureus obtained by protoplast transformation and agrobacterium-mediated dna transfer.	the high-level pigment-producing monascus strain ibcc1 was characterized by random amplification of polymorphic dna as m. purpureus. this technique allowed us to distinguish between m. purpureus and m. ruber strains. transformation of monascus species has not been previously reported. protoplast formation and regeneration from m. purpureus ibcc1 was optimized by modification of growth media, lytic enzyme mixture, osmotic stabilizer and regeneration media. of the monascus transformants, 60% were ...	2003	12838368
silver birch (betula pendula) plants with aux and rol genes show consistent changes in morphology, xylem structure and chemistry.	the effects of agrobacterium pria4 rol and aux genes, controlled by their endogenous promoters, on tree growth and wood anatomy and chemistry were studied in 5- and 7-year-old silver birch (betula pendula roth) plants. southern hybridization confirmed the following rol and aux gene combinations: control plants (no genes transferred); plants with rolc and rold genes; plants with rola, rolb, rolc and rold genes; and plants with rola, rolb, rolc, rold, aux1 and aux2 genes. transgene mrna was most a ...	2003	12839726
extracellular proteins involved in soybean cultivar-specific nodulation are associated with pilus-like surface appendages and exported by a type iii protein secretion system in sinorhizobium fredii usda257.	several gram-negative plant and animal pathogenic bacteria have evolved a type iii secretion system (ttss) to deliver effector proteins directly into the host cell cytosol. sinorhizobium fredii usda257, a symbiont of soybean and many other legumes, secretes proteins called nops (nodulation outer proteins) into the extracellular environment upon flavonoid induction. mutation analysis and the nucleotide sequence of a 31.2-kb symbiosis (sym) plasmid dna region of usda257 revealed the existence of a ...	2003	12848427
a luxr homolog, avir, in agrobacterium vitis is associated with induction of necrosis on grape and a hypersensitive response on tobacco.	a tn5 mutant of agrobacterium vitis f2/5 (m1154) differs from the wild-type strain in that it has lost its abilities to cause necrosis on grape and a hypersensitive-like response (hr) on tobacco. the tn5 insertion occurred in an open reading frame (orf) avir that is homologous to genes encoding the luxr family of transcriptional regulators, thereby suggesting that the hr and necrosis are regulated by a quorum-sensing system. fewer n-acyl-homoserine lactone autoinducers were detected in extracts ...	2003	12848431
transfer of t-dna and vir proteins to plant cells by agrobacterium tumefaciens induces expression of host genes involved in mediating transformation and suppresses host defense gene expression.	agrobacterium tumefaciens is a plant pathogen that incites crown gall tumors by transferring to and expressing a portion of a resident plasmid in plant cells. currently, little is known about the host response to agrobacterium infection. using suppressive subtractive hybridization and dna macroarrays, we identified numerous plant genes that are differentially expressed during early stages of agrobacterium-mediated transformation. expression profiling indicates that agrobacterium infection induce ...	2003	12848827
topological characterization of an inner membrane (1-->3)-beta-d-glucan (curdlan) synthase from agrobacterium sp. strain atcc31749.	the crds gene of agrobacterium sp. strain atcc31749 encodes the curdlan synthase (crds) protein based on the homology of the derived crds protein sequence with those of beta-glycosyl transferases with repetitive action patterns (stasinopoulos et al. [1999] glycobiology, 9, 31-41). here we show that chemical (ntg) mutagenesis of crds abolishes curdlan production and the induced mutations can be complemented by a cloned crds amplicon, thus providing genetic confirmation that crds is essential for ...	2003	12851288
engineering crops, a deserving venture.	plant transformation has had a deep impact on several aspects of basic and applied research. genetic transformation has offered new opportunities compared to traditional breeding practises since it allows the integration into a host genome of specific sequences leading to a strong reduction of the casualness of gene transfer. one of the first target areas was plant protection against pests, pathogens and environmental stresses while the recent plant engineering programs are aimed at increasing f ...	2003	12852173
the arabidopsis atlig4 gene is required for the repair of dna damage, but not for the integration of agrobacterium t-dna.	the joining of breaks in the chromosomal dna backbone by ligases in processes of replication, recombination and repair plays a crucial role in the maintenance of genomic stability. four atp-dependent ligases, designated dna ligases i-iv, have been identified in higher eukaryotes, and each one has distinct functions. in mammals and yeast, dna ligase iv is exclusively involved in the repair of dna double-strand breaks by non-homologous end joining. recently, an arabidopsis thaliana orthologue of t ...	2003	12853643
molecular simulations to determine the chelating mechanisms of various metal ions to the his-tag motif: a preliminary study.	in the present study, molecular simulations were performed to investigate the chelating mechanisms of various metal ions to the his-tag motifs with various his residues. the chelation mostly involved the i and i+2 his residues for ni(2+), zn(2+), cu(2+), and co(2+), while the cooperation of 3 his residues was necessary when fe(3+) was involved in chelation with his-tags having more than 4 his residues. metal ion was best fitted into the pocket formed by the imidazole nitrogens while it was about ...	2003	12854957
transformation of mucor miehei results in plasmid deletion and phenotypic instability.	mucor miehei transformants resistant to geneticin have been obtained by treatment of protoplasts with different plasmids and by agrobacterium-mediated dna transfer. all transformants exhibited a very unstable phenotype whose maintenance required continuous selective pressure. molecular analysis of transformants showed that the plasmid dna was extensively modified and maintained in very low amount. our results indicate that m. miehei reluctance to transformation is due to different causes, includ ...	2003	12855175
functional analysis of rf2a, a rice transcription factor.	rf2a is a bzip transcription factor that regulates expression of the promoter of rice tungro bacilliform badnavirus. rf2a is predicted to include three domains that contribute to its function. the results of transient assays with mutants of rf2a from which one or more domains were removed demonstrated that the acidic domain was essential for the activation of gene expression, although the proline-rich and glutamine-rich domains each played a role in this function. studies using fusion proteins o ...	2003	12855676
the lotus japonicus ndx gene family is involved in nodule function and maintenance.	to elucidate the function of the ndx homeobox genes during the rhizobium-legume symbiosis, two lotus japonicus ndr genes were expressed in the antisense orientation under the control of the nodule-expressed promoter psenod12 in transgenic lotus japonicus plants. many of the transformants obtained segregated into plants that failed to sustain proper development and maintenance of root nodules concomitant with down-regulation of the two ndx genes. the root nodules were actively fixing nitrogen 3 w ...	2003	12856938
the agrobacterium oncogene ab-6b causes a graft-transmissible enation syndrome in tobacco.	agrobacterium 6b oncogenes induce tumours and modify plant growth in various ways. here we show that the ab-6b gene from strain ab4 placed under 2x35s promoter control (2x35s-ab-6b) induces a complex enation syndrome in transgenic nicotiana tabacum plants, that also occurs in a few rare cases of genetic enations. in arabidopsis thaliana, 2x35s-ab-6b induced radially symmetrical tubes on the abaxial side of the leaves, which must therefore be considered as the arabidopsis equivalents of enations ...	2003	12856952
transformation of plant science in our time-the contribution of jozef s. schell (1935-2003).		2003	12857791
identification of a novel alpha-proteobacterium causing bacteraemia in an immunocompetent patient.	an 89-year male with pyrexia and suspected bacteremia was admitted to hospital, where a gram-negative rod was identified from blood culture. the organism was difficult to identify phenotypically and the resulting sequencing of a 559 bp section of the 16s rrna gene did not have a high homology score (>97.0%) with any deposited genbank accession numbers and hence was not able to be assigned to a species within any genus. given that the isolate was a member of the alpha subclass of the proteobacter ...	2003	12860153
immx immunity region of rhizobium phage 16-3: two overlapping cistrons of repressor function.	16-3 is a temperate phage of the symbiotic nitrogen-fixing bacterium rhizobium meliloti 41. its prophage state and immunity against superinfection by homoimmune phages are governed by a complex set of controls: the immc and immx repressor systems and the avirt element are all located in well-separated, distinct regions which span 25 kb on the bacteriophage chromosome. the anatomy and function of the immc region are well documented; however, fewer analyses have addressed the immx and avirt region ...	2003	12867446
expression cloning and biochemical characterization of a rhizobium leguminosarum lipid a 1-phosphatase.	lipid a of rhizobium leguminosarum, a nitrogen-fixing plant endosymbiont, displays several significant structural differences when compared with escherichia coli. an especially striking feature of r. leguminosarum lipid a is that it lacks both the 1- and 4'-phosphate groups. distinct lipid a phosphatases that attack either the 1 or the 4' positions have previously been identified in extracts of r. leguminosarum and rhizobium etli but not sinorhizobium meliloti or e. coli. here we describe the id ...	2003	12869541
fused rola protein enhances beta-glucoronidase activity 50-fold: implication for rola mechanism of action.	we report that the plant oncoprotein rola from agrobacterium rhizogenes acts to stabilize beta-glucoronidase (gus) when the two proteins are expressed as a fusion protein in transformed tobacco. the observed 50-fold increase of gus activity was shown to be related to protein accumulation, with no significant changes in mrna abundance, kinetic properties of the enzyme and thermostability. the entire rola sequence is essential to achieve the full effect since both the n-terminal region, spanning a ...	2003	12871150
purification and crystallization of a lysr-type transcriptional regulator cbnr from ralstonia eutropha nh9.	cbnr, a lysr-type transcriptional regulator from ralstonia eutropha nh9, has been crystallized by the vapor-diffusion method. it is intriguing to note that the different mixing ratios between the protein and reservoir solutions resulted in the different crystal forms. these crystals have the symmetry of the orthorhombic system with space groups p2(1)1(i)2 and p2(1)2(1)2(1).	2003	12871153
a new subfamily of the nudix hydrolase superfamily active on 5-methyl-utp (ribo-ttp) and utp.	a new subfamily of the nudix hydrolases, identified by conserved amino acids upstream and downstream of the nudix box, has been characterized. the cloned, expressed, and purified orthologous enzymes have major activities on the non-canonical nucleoside triphosphate 5-methyl-utp (ribo-ttp) and the canonical nucleotide utp. in addition to their homologous signature sequences and their similar substrate specificities, the members of the subfamily are inhabitants of or are related to the bacterial r ...	2003	12871944
morphological compatibility of white clover and perennial ryegrass cultivars grown under two nitrate levels in flowing solution culture.	the effects of nitrate (no3-) supply on shoot morphology, vertical distribution of shoot and root biomass and total nitrogen (n) acquisition by two perennial ryegrass (lolium perenne l.) cultivars (aberelan and preference) and two white clover (trifolium repens l.) cultivars (grasslands huia and aberherald) were studied in flowing nutrient culture. cultivars were grown from seed as monocultures and the clovers inoculated with rhizobium. the 6-week measurement period began on day 34 (grasses) and ...	2003	12876188
development of linum flavum hairy root cultures for production of coniferin.	linum flavum hairy roots were initiated from leaf discs using agrobacterium rhizogenes strains lba9402 and tr105 though two other strains, 15834 and a4, were relatively ineffective for induction. significant variation in coniferin accumulation was observed between hairy root lines originating from different l. flavum seedlings and/or a. rhizogenes strains. coniferin reached 58 mg g-1 dry wt by culturing the roots in linsmaier and skoog (ls) medium with 2,4-dichlorophenoxyacetic acid and naphthal ...	2003	12882138
production of ajmalicine and ajmaline in hairy root cultures of rauvolfia micrantha hook f., a rare and endemic medicinal plant.	hairy roots of rauvolfia micrantha were induced from hypocotyl explants of 2-3 weeks old aseptic seedlings using agrobacterium rhizogenes atcc 15834. hairy roots grown in half-strength murashige & skoog (ms) medium with 0.2 mg indole 3-butyric acid l-1 and 0.1 mg alpha-naphthaleneacetic acid l-1 produced more ajmaline (0.01 mg g-1 dry wt) and ajmalicine (0.006 mg g-1 dry wt) than roots grown in auxin-free medium. ajmaline (0.003 mg g-1 dry wt) and ajmalicine (0.0007 mg g-1 dry wt) were also prod ...	2003	12882157
rhizobium radiobacter conjugation and callus-independent shoot regeneration used to introduce the cercosporin export gene cfp from cercospora into sugar beet (beta vulgaris l.).	leaf spot disease caused by cercospora is responsible for crop and profitability losses in sugar beet crops in the us and worldwide. the cfp gene that encodes a protein that exports phytotoxic cercosporins from cercospora was conjugally transferred to sugar beet using rhizobium radiobacter (agrobacterium tumefaciens), to improve cercospora-induced leafspot resistance. conditions for shoot regeneration were optimized to increase regeneration/transformation efficiencies. low-light and room-tempera ...	2003	12882176
enhanced biosynthesis of polyhydroxyalkanoates in a mutant strain of rhizobium meliloti.	strains of rhizobium spp. isolated from leguminous plants and standard strains accumulated 27% to 57% polyhydroxyalkanoate (pha) of their cell biomass. among these cultures, one strain of rhizobium meliloti synthesized 10-30% more pha than others and contained 3% hydroxyvalerate (hv) when grown on sucrose as carbon substrate. the occurrence of hydroxybutyrate (hb) and hv was confirmed by gc and 1h nmr analysis. treatment of the culture with 4'-n-piperidinobutyl-2-chlorophenoxazine resulted in a ...	2003	12882285
enhanced hydantoinase and n-carbamoylase activity on immobilisation of agrobacterium tumefaciens.	cell extracts of agrobacterium tumefaciens, immobilised in calcium alginate beads, had a 7-fold increase in n-carbamoylase (n-carbamylamino acid amidohydrolase e.c. 3.5.1) activity on reaction with n-carbamylglycine. the hydantoinase (dihydropyrimidinase e.c. 3.5.2.2) and n-carbamoylase activities remained stable over 4 weeks storage at 4 degrees c relative to the non-immobilised enzymes, with the hydantoinase activity showing a 5-fold increase in activity relative to the non-immobilised hydanto ...	2003	12882309