Publications

the six functions of agrobacterium vire2.		2001	11209039
enhanced symbiotic performance by rhizobium tropici glycogen synthase mutants.	we isolated a tn5-induced rhizobium tropici mutant that has enhanced capacity to oxidize n,n-dimethyl-p-phenylendiamine (dmpd) and therefore has enhanced respiration via cytochrome oxidase. the mutant had increased levels of the cytochromes c(1) and cycm and a small increase in the amount of cytochrome aa(3). in plant tests, the mutant increased the dry weight of phaseolus vulgaris plants by 20 to 38% compared with the control strain, thus showing significantly enhanced symbiotic performance. th ...	2001	11208782
identification of a genomic island present in the majority of pathogenic isolates of pseudomonas aeruginosa.	pseudomonas aeruginosa, a ubiquitous gram-negative bacterium, is capable of colonizing a wide range of environmental niches and can also cause serious infections in humans. in order to understand the genetic makeup of pathogenic p. aeruginosa strains, a method of differential hybridization of arrayed libraries of cloned dna fragments was developed. an m13 library of dna from strain x24509, isolated from a patient with a urinary tract infection, was screened using a dna probe from p. aeruginosa s ...	2001	11208781
active expression of the ubia gene from e. coli in tobacco: influence of plant er-specific signal peptides on the expression of a membrane-bound prenyltransferase in plant cells.	the ubia gene from e. coli codes for 4-hydroxybenzoate: polyprenyldiphosphate 3-polyprenyltransferase, an integral membrane protein involved in ubiquinone biosynthesis. this prokaryotic membrane protein was stably expressed in tobacco using agrobacterium tumefaciens-mediated transformation. transgenic lines containing a direct fusion of the ubia structural gene to a 35s-derived promoter gave very low enzyme activity levels (average 0.16 pkat/mg). inclusion of an n-terminal er-specific signal pep ...	2000	11206977
isolation and bioactivities of epidioxysterol from the tunicate cynthia savignyi.	from a hexane extract of the tunicate cynthia savignyi, collected in morocco, epidioxysterol or 5,8-alpha-epidioxy-5alpha-cholest-6-en-3beta-ol has been isolated. this is the first example of epidioxysterol found in the tunicate c. savignyi. the structure of epidioxysterol has been characterised by nmr data (1h, 13c and 2d). epidioxysterol possesses antifungal activity against three tomato pathogenic fungi: botrytis cinerea, fusarium oxysporum and verticillium albo atrum and antibacterial activi ...	2000	11204751
agrobacterium-mediated sorghum transformation.	agrobacterium tumefaciens was used to genetically transform sorghum. immature embryos of a public (p898012) and a commercial line (phi391) of sorghum were used as the target explants. the agrobacterium strain used was lba4404 carrying a 'super-binary' vector with a bar gene as a selectable marker for herbicide resistance in the plant cells. a series of parameter tests was used to establish a baseline for conditions to be used in stable transformation experiments. a number of different transforma ...	2000	11202440
construction of a derivative of agrobacterium tumefaciens c58 that does not mutate to tetracycline resistance.	agrobacterium tumefaciens c58 mutates to tetracycline resistance at high frequency, complicating the use of many broad-host-range cloning and binary vectors that code for resistance to this antibiotic as the selection marker. such mutations are associated with a resistant gene unit, tetc58, that is present in the genome of this strain. by deleting the tetc58 locus, we constructed ntl4, a derivative of c58 that no longer mutates to tetracycline resistance. the deletion had no detectable effect on ...	2001	11194879
virulence functions of autotransporter proteins.		2001	11179284
from rags to riches: insights from the first genomic sequence of a plant pathogenic bacterium.	the recently published genomic sequence of xylella fastidiosa is the first for a free-living plant pathogen and provides clues to mechanisms of pathogenesis and survival in insect vectors. the sequence data should lead to improved control of this pathogen.	2000	11178244
ancient origin of pathogen recognition specificity conferred by the tomato disease resistance gene pto.	we have investigated the origin of the pto disease resistance (r) gene that was previously identified in the wild tomato species lycopersicon pimpinellifolium and isolated by map-based cloning. pto encodes a serine-threonine protein kinase that specifically recognizes strains of pseudomonas syringae pv. tomato (pst) that express the avirulence gene avrpto. we examined an accession of the distantly related wild species lycopersicon hirsutum var. glabratum that exhibits avrpto-specific resistance ...	2001	11172075
genetic transformation of hela cells by agrobacterium.	agrobacterium tumefaciens is a soil phytopathogen that elicits neoplastic growths on the host plant species. in nature, however, agrobacterium also may encounter organisms belonging to other kingdoms such as insects and animals that feed on the infected plants. can agrobacterium, then, also infect animal cells? here, we report that agrobacterium attaches to and genetically transforms several types of human cells. in stably transformed hela cells, the integration event occurred at the right borde ...	2001	11172043
the quorum-sensing transcriptional regulator trar requires its cognate signaling ligand for protein folding, protease resistance, and dimerization.	complexes between the quorum-sensing regulator trar and its inducing ligand autoinducer (aai) are soluble in escherichia coli, whereas apo-trar is almost completely insoluble. here we show that the lack of soluble trar is due in large part to rapid proteolysis, inasmuch as apo-trar accumulated to high levels in an e. coli strain deficient in clp and lon proteases. in pulse labeling experiments, aai protected trar against proteolysis only when it was added before the radiolabel. this observation ...	2001	11171981
transgenic crop plants expressing synthetic cry9aa gene are protected against insect damage.	a synthetic gene sequence of cry9aa was made to achieve high expression levels in a plant cell. tobacco, potato, cauliflower and turnip rape plants were transformed with this synthetic gene driven by the double 35s promoter using agrobacterium tumefaciens lba4404. the presence and expression of the synthetic cry9aa gene was evaluated in southern, northern and western analysis and with insect bioassays. the expression of the gene in tobacco plants reached a level of 5 pg of mrna per 1 µg of total ...	2001	11164606
two-step purification of d(-)-specific carbamoylase from agrobacterium tumefaciens am 10.	a simple, economical and rapid affinity chromatography procedure with red dye as a ligand has been described for the two-step purification of a relatively thermostable d(-)-carbamoylase from the cell-free extract of agrobacterium tumefaciens am 10. the enzyme was purified 232-fold to homogeneity with a recovery of 30% in the presence of 2 mm dithiothreitol. the specific activity of the enzyme was 7.88 u/mg protein. the enzyme is a dimer with a native molecular mass of 67 kda and a subunit relati ...	2001	11162403
overexpression of 3-ketoacyl-acyl-carrier protein synthase iiis in plants reduces the rate of lipid synthesis.	a cdna coding for 3-ketoacyl-acyl-carrier protein (acp) synthase iii (kas iii) from spinach (spinacia oleracea; so kas iii) was used to isolate two closely related kas iii clones (ch kas iii-1 and ch kas iii-2) from cuphea hookeriana. both ch kas iiis are expressed constitutively in all tissues examined. an increase in the levels of 16:0 was observed in tobacco (nicotiana tabacum, wt-sr) leaves overexpressing so kas iii when under the control of the cauliflower mosaic virus-35s promoter and in a ...	2001	11161065
sucrose metabolism in plastids.	the question whether sucrose (suc) is present inside plastids has been long debated. low suc levels were reported to be present inside isolated chloroplasts, but these were argued to be artifacts of the isolation procedures used. we have introduced suc-metabolizing enzymes in plastids and our experiments suggest substantial suc entry into plastids. the enzyme levansucrase from bacillus subtilis efficiently synthesizes fructan from suc. targeting of this enzyme to the plastids of tobacco (nicotia ...	2001	11161049
the calcium rhythms of different cell types oscillate with different circadian phases.	transgenic tobacco (nicotiana plumbaginifolia) seedlings containing the ca(2+)-sensitive luminescent protein aequorin have been shown to exhibit circadian variations in cytosolic calcium. concomitant measurements of cytosolic and nuclear calcium show that circadian variations in the cytoplasm are not expressed in the nucleus. to investigate whether all cells of transgenic seedlings contribute equally to circadian variations in cytosolic calcium, different promoters eliciting different expression ...	2001	11161036
the 5' end of the pea ferredoxin-1 mrna mediates rapid and reversible light-directed changes in translation in tobacco.	ferredoxin-1 (fed-1) mrna contains an internal light response element (ilre) that destabilizes mrna when light-grown plants are placed in darkness. mrnas containing this element dissociate from polyribosomes in the leaves of transgenic tobacco (nicotiana tabacum) plants transferred to the dark for 2 d. here, we report in vivo labeling experiments with a chloramphenicol acetyl transferase mrna fused to the fed-1 ilre. our data indicate that the fed-1 ilre mediates a rapid decline in translational ...	2001	11161034
molecular interactions between the specialist herbivore manduca sexta (lepidoptera, sphingidae) and its natural host nicotiana attenuata. i. large-scale changes in the accumulation of growth- and defense-related plant mrnas.	plants respond to herbivore attack with a dramatic functional reorganization that involves the activation of direct and indirect defenses and tolerance, which in turn make large demands on primary metabolism. here we provide the first characterization of the transcriptional reorganization that occurs after insect attack in a model plant-herbivore system: nicotiana attenuata torr. ex wats.-manduca sexta. we used mrna differential display to characterize one-twentieth of the insect-responsive tran ...	2001	11161026
hydrophobic interactions of the structural protein grp1.8 in the cell wall of protoxylem elements.	the glycine-rich structural protein grp1.8 of french bean (phaseolus vulgaris) is specifically localized in the modified primary cell walls of protoxylem elements. continuous deposition of grp1.8 into the cell walls during elongation growth of the plant suggests that grp1.8 is part of a repair mechanism to strengthen the protoxylem. in this work, a reporter-protein system was developed to study the interaction of grp1.8 with the extracellular matrix. fusion proteins of a highly soluble chitinase ...	2001	11161025
cloning of an arabidopsis patatin-like gene, sturdy, by activation t-dna tagging.	activation t-dna tagging can generate dominant gain-of-function mutants by overexpression of a particular endogenous gene. we identified an activation-tagged mutant, sturdy, exhibiting a stiff inflorescence stem, thicker leaves, shorter siliques, larger seeds, round-shaped flowers, and delayed growth. it is most important that unlike its wild-type counterpart, this mutant is less prone to lodging. cloning of sturdy revealed that in sturdy, there is an open reading frame containing a single intro ...	2001	11161015
the hook gene (flge) is expressed from the flgbcdef operon in rhodobacter sphaeroides: study of an flge mutant.	in this work we identified the flge gene encoding the flagellar hook protein from rhodobacter sphaeroides. our results show that this gene is part of a flagellar cluster that includes the genes flgb, flgc, flgd, flge, and flgf. two different types of mutants in the flge gene were isolated, and both showed a fla(-) phenotype, indicating the functionality of this sequence. complementation studies of these mutant strains suggest that flge is included in a single transcriptional unit that starts in ...	2001	11160099
nucleotide sequence and analysis of conjugative plasmid pvt745.	the complete nucleotide sequence and genetic map of pvt745 are presented. the 25-kb plasmid was isolated from actinobacillus actinomycetemcomitans, a periodontal pathogen. two-thirds of the plasmid encode functions related to conjugation, replication, and replicon stability. among potential gene products with a high degree of similarity to known proteins are those associated with plasmid conjugation. it was shown that pvt745 derivatives not only mobilized a coresident nontransmissible plasmid, p ...	2001	11160089
gene discovery through genomic sequencing of brucella abortus.	brucella abortus is the etiological agent of brucellosis, a disease that affects bovines and human. we generated dna random sequences from the genome of b. abortus strain 2308 in order to characterize molecular targets that might be useful for developing immunological or chemotherapeutic strategies against this pathogen. the partial sequencing of 1,899 clones allowed the identification of 1,199 genomic sequence surveys (gsss) with high homology (blast expect value < 10(-5)) to sequences deposite ...	2001	11159979
trh1 encodes a potassium transporter required for tip growth in arabidopsis root hairs.	root hair initiation involves the formation of a bulge at the basal end of the trichoblast by localized diffuse growth. tip growth occurs subsequently at this initiation site and is accompanied by the establishment of a polarized cytoplasmic organization. arabidopsis plants homozygous for a complete loss-of-function tiny root hair 1 (trh1) mutation were generated by means of the t-dna-tagging method. trichoblasts of trh1 plants form initiation sites but fail to undergo tip growth. a predicted pr ...	2001	11158535
a mutation of the mitochondrial abc transporter sta1 leads to dwarfism and chlorosis in the arabidopsis mutant starik.	a mutation in the arabidopsis gene starik leads to dwarfism and chlorosis of plants with an altered morphology of leaf and cell nuclei. we show that the starik gene encodes the mitochondrial abc transporter sta1 that belongs to a subfamily of arabidopsis half-abc transporters. the severity of the starik phenotype is suppressed by the ectopic expression of the sta2 homolog; thus, sta1 function is partially redundant. sta1 supports the maturation of cytosolic fe/s protein in deltaatm1 yeast, subst ...	2001	11158531
downregulation of caffeic acid 3-o-methyltransferase and caffeoyl coa 3-o-methyltransferase in transgenic alfalfa. impacts on lignin structure and implications for the biosynthesis of g and s lignin.	transgenic alfalfa plants were generated harboring caffeic acid 3-o-methyltransferase (comt) and caffeoyl coa 3-o-methyltransferase (ccomt) cdna sequences under control of the bean phenylalanine ammonia-lyase pal2 promoter. strong downregulation of comt resulted in decreased lignin content, a reduction in total guaiacyl (g) lignin units, a near total loss of syringyl (s) units in monomeric and dimeric lignin degradation products, and appearance of low levels of 5-hydroxy guaiacyl units and a nov ...	2001	11158530
genetic characterization of a sinorhizobium meliloti chromosomal region in lipopolysaccharide biosynthesis.	the genetic characterization of a 5.5-kb chromosomal region of sinorhizobium meliloti 2011 that contains lpsb, a gene required for the normal development of symbiosis with medicago spp., is presented. the nucleotide sequence of this dna fragment revealed the presence of six genes: grea and lpsb, transcribed in the forward direction; and lpse, lpsd, lpsc, and lrp, transcribed in the reverse direction. except for lpsb, none of the lps genes were relevant for nodulation and nitrogen fixation. analy ...	2001	11157937
identification, purification, and characterization of iminodiacetate oxidase from the edta-degrading bacterium bnc1.	microbial degradation of synthetic chelating agents, such as edta and nitrilotriacetate (nta), may help immobilizing radionuclides and heavy metals in the environment. the edta- and nta-degrading bacterium bnc1 uses edta monooxygenase to oxidize nta to iminodiacetate (ida) and edta to ethylenediaminediacetate (edda). ida- and edda-degrading enzymes have not been purified and characterized to date. in this report, an ida oxidase was purified to apparent homogeneity from strain bnc1 by using a com ...	2001	11157233
cloning, sequencing, and characterization of a gene cluster involved in edta degradation from the bacterium bnc1.	edta is a chelating agent, widely used in many industries. because of its ability to mobilize heavy metals and radionuclides, it can be an environmental pollutant. the edta monooxygenases that initiate edta degradation have been purified and characterized in bacterial strains bnc1 and dsm 9103. however, the genes encoding the enzymes have not been reported. the edta monooxygenase gene was cloned by probing a genomic library of strain bnc1 with a probe generated from the n-terminal amino acid seq ...	2001	11157232
iron-binding compounds from agrobacterium spp.: biological control strain agrobacterium rhizogenes k84 produces a hydroxamate siderophore.	iron-binding compounds were produced in various amounts in response to iron starvation by a collection of agrobacterium strains belonging to the species a. tumefaciens, a. rhizogenes, and a. vitis. the crown gall biocontrol agent a. rhizogenes strain k84 produced a hydroxamate iron chelator in large amounts. production of this compound, and also of a previously described antibiotic-like substance called als84, occurred only in cultures of strain k84 grown in iron-deficient medium. similarly, sen ...	2001	11157228
alpha- and beta-proteobacteria control the consumption and release of amino acids on lake snow aggregates.	we analyzed the composition of aggregate (lake snow)-associated bacterial communities in lake constance from 1994 until 1996 between a depth of 25 m and the sediment surface at 110 m by fluorescent in situ hybridization with rrna-targeted oligonucleotide probes of various specificity. in addition, we experimentally examined the turnover of dissolved amino acids and carbohydrates together with the microbial colonization of aggregates formed in rolling tanks in the lab. generally, between 40 and m ...	2001	11157226
kojak encodes a cellulose synthase-like protein required for root hair cell morphogenesis in arabidopsis.	the cell wall is an important determinant of plant cell form. here we define a class of arabidopsis root hair mutants with defective cell walls. plants homozygous for kojak (kjk) mutations initiate root hairs that rupture at their tip soon after initiation. the kjk gene was isolated by positional cloning, and its identity was confirmed by the molecular complementation of the kjk(-) phenotype and the sequence of three kjk mutant alleles. kojak encodes a cellulose synthase-like protein, atcsld3. k ...	2001	11156607
a nuclear casein kinase 2 activity is involved in early events of transcriptional activation induced by salicylic acid in tobacco.	salicylic acid (sa) activates immediate early transcription of genes controlled by a family of dna promoter elements named as-1-like elements. these elements are functional in the promoter of glutathione s-transferase genes. we have previously shown that sa increases the binding of tobacco (nicotiana tabacum cv xanthi nc) nuclear factors to the as-1 sequence in a process mediated by protein phosphorylation. in this study we give evidence for the participation of a nuclear protein kinase ck2 (cas ...	2001	11154347
biliverdin reductase-induced phytochrome chromophore deficiency in transgenic tobacco.	targeted expression of mammalian biliverdin ixalpha reductase (bvr), an enzyme that metabolically inactivates linear tetrapyrrole precursors of the phytochrome chromophore, was used to examine the physiological functions of phytochromes in the qualitative short-day tobacco (nicotiana tabacum cv maryland mammoth) plant. comparative phenotypic and photobiological analyses of plastid- and cytosol-targeted bvr lines showed that multiple phytochrome-regulated processes, such as hypocotyl and internod ...	2001	11154335
molecular and biochemical analysis of a madagascar periwinkle root-specific minovincinine-19-hydroxy-o-acetyltransferase.	the terminal steps in the biosynthesis of the monoterpenoid indole alkaloids vindoline and minovincinine are catalyzed by separate acetyl coenzyme a-dependent o-acetyltransferases in madagascar periwinkle (catharanthus roseus g. don). two genes were isolated that had 63% nucleic acid identity and whose deduced amino acid sequences were 78% identical. active enzymes that were expressed as recombinant his-tagged proteins in escherichia coli were named minovincinine-19-o-acetyltransferase (mat) and ...	2001	11154328
regulation of starch accumulation by granule-associated plant 14-3-3 proteins.	in higher plants the production of starch is orchestrated by chloroplast-localized biosynthetic enzymes, namely starch synthases, adp-glucose pyrophosphorylase, and starch branching and debranching enzymes. diurnal regulation of these enzymes, as well as starch-degrading enzymes, influences both the levels and composition of starch, and is dependent in some instances upon phosphorylation-linked regulation. the phosphoserine/threonine-binding 14-3-3 proteins participate in environmentally respons ...	2001	11149942
essential role of the small gtpase rac in disease resistance of rice.	production of reactive oxygen intermediates (roi) and a form of programmed cell death called hypersensitive response (hr) are often associated with disease resistance of plants. we have previously shown that the rac homolog of rice, osrac1, is a regulator of roi production and cell death in rice. here we show that the constitutively active osrac1 (i) causes hr-like responses and greatly reduces disease lesions against a virulent race of the rice blast fungus; (ii) causes resistance against a vir ...	2001	11149940
an agrobacterium vire2 channel for transferred-dna transport into plant cells.	transferred dna (t-dna) transfer from agrobacterium tumefaciens into eukaryotic cells is the only known example of interkingdom dna transfer. t-dna is a single-stranded segment of agrobacterium's tumor-inducing plasmid that enters the plant cell as a complex with the bacterial virulence proteins vird2 and vire2. the vire2 protein is highly induced on contact of a. tumefaciens with a plant host and has been reported to act in late steps of transfer. one of its previously demonstrated functions is ...	2001	11149937
multiple cellulose synthase catalytic subunits are required for cellulose synthesis in arabidopsis.	the irregular xylem 1 (irx1) mutant of arabidopsis has a severe deficiency in the deposition of cellulose in secondary cell walls, which results in collapsed xylem cells. this mutation has been mapped to a 140-kb region of chromosome 4. a cellulose synthase catalytic subunit was found to be located in this region, and genomic clones containing this gene complemented the irx1 mutation. irx1 shows homology to a previously described cellulose synthase (irx3). analysis of the irx1 and irx3 mutant ph ...	2000	11148295
myb-related transcription factor ntmyb2 induced by wounding and elicitors is a regulator of the tobacco retrotransposon tto1 and defense-related genes.	transposition of the tobacco retrotransposon tto1 is regulated mainly by transcription from the long terminal repeat (ltr). functional analysis of the ltr showed that the 13-bp motif is a cis-regulatory element involved in activation by tissue culture, wounding, and treatment with elicitors. the 13-bp motif contains a conserved motif (l box) that has been implicated in the expression of phenylpropanoid synthetic genes in response to defense-related stresses. to gain further insight into the regu ...	2000	11148294
cloning of the arabidopsis rsf1 gene by using a mapping strategy based on high-density dna arrays and denaturing high-performance liquid chromatography.	mapping genes by chromosome walking is a widely used technique applicable to cloning virtually any gene that is identifiable by mutagenesis. we isolated the gene responsible for the recessive mutation rsf1 (for reduced sensitivity to far-red light) in the arabidopsis columbia accession by using classical genetic analysis and two recently developed technologies: genotyping high-density oligonucleotide dna array and denaturing high-performance liquid chromatography (dhplc). the arabidopsis at412 g ...	2000	11148292
chilling tolerance in arabidopsis involves ala1, a member of a new family of putative aminophospholipid translocases.	the lipid composition of membranes is a key determinant for cold tolerance, and enzymes that modify membrane structure seem to be important for low-temperature acclimation. we have characterized ala1 (for aminophospholipid atpase1), a novel p-type atpase in arabidopsis that belongs to the gene family ala1 to ala11. the deduced amino acid sequence of ala1 is homologous with those of yeast drs2 and bovine atpase ii, both of which are putative aminophospholipid translocases. ala1 complements the de ...	2000	11148289
procuste1 encodes a cellulose synthase required for normal cell elongation specifically in roots and dark-grown hypocotyls of arabidopsis.	mutants at the procuste1 (prc1) locus show decreased cell elongation, specifically in roots and dark-grown hypocotyls. cell elongation defects are correlated with a cellulose deficiency and the presence of gapped walls. map-based cloning of prc1 reveals that it encodes a member (cesa6) of the cellulose synthase catalytic subunit family, of which at least nine other members exist in arabidopsis. mutations in another family member, rsw1 (cesa1), cause similar cell wall defects in all cell types, i ...	2000	11148287
cloning and characterization of iar1, a gene required for auxin conjugate sensitivity in arabidopsis.	most indole-3-acetic acid (iaa) in higher plants is conjugated to amino acids, sugars, or peptides, and these conjugates are implicated in regulating the concentration of the free hormone. we identified iar1 as an arabidopsis mutant that is resistant to the inhibitory effects of several iaa-amino acid conjugates but remains sensitive to free iaa. iar1 partially suppresses phenotypes of a mutant that overproduces iaa, suggesting that iar1 participates in auxin metabolism or response. we used posi ...	2000	11148286
mutations in the fie and mea genes that encode interacting polycomb proteins cause parent-of-origin effects on seed development by distinct mechanisms.	in flowering plants, two cells are fertilized in the haploid female gametophyte. egg and sperm nuclei fuse to form the embryo. a second sperm nucleus fuses with the central cell nucleus, which replicates to generate the endosperm, a tissue that supports embryo development. the fertilization-independent endosperm (fie) and medea (mea) genes encode wd and set domain polycomb proteins, respectively. in the absence of fertilization, a female gametophyte with a loss-of-function fie or mea allele init ...	2000	11148284
nuclear localization of npr1 is required for activation of pr gene expression.	systemic acquired resistance (sar) is a broad-spectrum resistance in plants that involves the upregulation of a battery of pathogenesis-related (pr) genes. npr1 is a key regulator in the signal transduction pathway that leads to sar. mutations in npr1 result in a failure to induce pr genes in systemic tissues and a heightened susceptibility to pathogen infection, whereas overexpression of the npr1 protein leads to increased induction of the pr genes and enhanced disease resistance. we analyzed t ...	2000	11148282
[regeneration of hnp transgenic alfalfa plants by agrobacterium mediated gene transfer].	transgenic plants regenerated from cotyledons of m. sativa l. infected using agrobacterium tumefaciens a281 with plasmid pbf649 containing a gene encoding protein of high sulfur-amino acid content (hnp) were obtained successfully. the plants grew and fertiled well in field. cotyledon explants were better recipient for transformation of m. sativa l. environment of suitable temperature (15 degrees c) and high humidity on high viability of the plants transplanted into soil were essential conditions ...	2000	11147352
competence of arabidopsis thaliana genotypes and mutants for agrobacterium tumefaciens-mediated gene transfer: role of phytohormones.	many plant species and/or genotypes are highly recalcitrant to agrobacterium-mediated genetic transformation, and yet little is known about this phenomenon. using several arabidopsis genotypes/ecotypes, the results of this study indicated that phytohormone pretreatment could overcome this recalcitrance by increasing the transformation rate in the known recalcitrant genotypes. transient expression of a t-dna encoded ss-glucuronidase (gus) gene and stable kanamycin resistance were obtained for the ...	2000	11141170
vascularization is a general requirement for growth of plant and animal tumours.	solid-tumour growth in animals as in humans depends on angiogenesis. tumours that fail to induce the formation of new blood vessels do not enlarge beyond a few millimetres in diameter. plant tumours induced by agrobacterium tumefaciens can reach diameters of more than 100 mm, thus raising the question of how they are sufficiently supplied with nutrients and water. until recently, these rapidly growing tumours were considered unorganized or partly organized masses. however, in analogy to animal a ...	2000	11141169
the use of transgenic fruit trees as a resistance strategy for virus epidemics: the plum pox (sharka) model.	sharka or plum pox, caused by plum pox virus (ppv: genus potyvirus; family potyviridae), is the most serious disease of prunus. most cultivated prunus species are highly susceptible and conventional breeding has not produced highly resistant and commercially acceptable varieties. success in developing virus-resistant herbaceous crops through genetic engineering led us to investigate this approach for resistance to ppv. our programme aims to develop a biotechnological approach to ppv control that ...	2000	11137162
limited genetic diversity of brucella spp.	multilocus enzyme electrophoresis (mlee) of 99 brucella isolates, including the type strains from all recognized species, revealed a very limited genetic diversity and supports the proposal of a monospecific genus. in mlee-derived dendrograms, brucella abortus and a marine brucella sp. grouped into a single electrophoretic type related to brucella neotomae and brucella ovis. brucella suis and brucella canis formed another cluster linked to brucella melitensis and related to rhizobium tropici. th ...	2001	11136777
metabolic engineering of plant alkaloid biosynthesis.	plant alkaloids, one of the largest groups of natural products, provide many pharmacologically active compounds. several genes in the biosynthetic pathways for scopolamine, nicotine, and berberine have been cloned, making the metabolic engineering of these alkaloids possible. expression of two branching-point enzymes was engineered: putrescine n-methyltransferase (pmt) in transgenic plants of atropa belladonna and nicotiana sylvestris and (s)-scoulerine 9-o-methyltransferase (smt) in cultured ce ...	2000	11134522
metabolic engineering of plant alkaloid biosynthesis.	plant alkaloids, one of the largest groups of natural products, provide many pharmacologically active compounds. several genes in the biosynthetic pathways for scopolamine, nicotine, and berberine have been cloned, making the metabolic engineering of these alkaloids possible. expression of two branching-point enzymes was engineered: putrescine n-methyltransferase (pmt) in transgenic plants of atropa belladonna and nicotiana sylvestris and (s)-scoulerine 9-o-methyltransferase (smt) in cultured ce ...	2000	11134522
identification of the nik gene cluster of brucella suis: regulation and contribution to urease activity.	analysis of a brucella suis 1330 gene fused to a gfp reporter, and identified as being induced in j774 murine macrophage-like cells, allowed the isolation of a gene homologous to nika, the first gene of the escherichia coli operon encoding the specific transport system for nickel. dna sequence analysis of the corresponding b. suis nik locus showed that it was highly similar to that of e. coli except for localization of the nikr regulatory gene, which lies upstream from the structural nikabcde ge ...	2001	11133934
effect of introns and at-rich sequences on expression of the bacterial hygromycin b resistance gene in the basidiomycete schizophyllum commune.	previously, it was shown that introns are required for efficient mrna accumulation in schizophyllum commune and that the presence of at-rich sequences in the coding region of genes can result in truncation of transcripts in this homobasidiomycete. here we show that intron-dependent mrna accumulation and truncation of transcripts are two independent events that both affect expression of the bacterial hygromycin b resistance gene in s. commune.	2001	11133486
gene cloning and functional characterization by heterologous expression of the fructosyltransferase of aspergillus sydowi iam 2544.	we have purified a fructosyltransferase from conidia of the inulin-producing fungus aspergillus sydowi iam 2544 and obtained peptide sequences from proteolytic fragments of the protein. with degenerated primers, we amplified a pcr fragment that was used to screen a cdna library. the fructosyltransferase gene from aspergillus sydowi (embl accession no. aj289046) is expressed in conidia, while no expression could be detected in mycelia by northern blot analysis of mycelial rna. the gene encodes a ...	2001	11133467
pantoea agglomerans strain eh318 produces two antibiotics that inhibit erwinia amylovora in vitro.	pantoea agglomerans (synonym: erwinia herbicola) strain eh318 produces through antibiosis a complex zone of inhibited growth in an overlay seeded with erwinia amylovora, the causal agent of fire blight. this zone is caused by two antibiotics, named pantocin a and b. using a genomic library of eh318, two cosmids, pcpp702 and pcpp704, were identified that conferred on escherichia coli the ability to inhibit growth of e. amylovora. the two cosmids conferred different antibiotic activities on e. col ...	2001	11133457
polyclonal antibodies recognizing the amob protein of ammonia oxidizers of the beta-subclass of the class proteobacteria.	a 41-kda protein of nitrosomonas eutropha was purified, and the n-terminal amino acid sequence was found to be nearly identical with the sequence of amob, a subunit of ammonia monooxygenase. this protein was used to develop polyclonal antibodies, which were highly specific for the detection of the four genera of ammonia oxidizers of the beta-subclass of proteobacteria (nitrosomonas, including nitrosococcus mobilis, which belongs phylogenetically to nitrosomonas; nitrosospira; nitrosolobus; and n ...	2001	11133435
novel tellurite-amended media and specific chromosomal and ti plasmid probes for direct analysis of soil populations of agrobacterium biovars 1 and 2.	ecology and biodiversity studies of agrobacterium spp. require tools such as selective media and dna probes. tellurite was tested as a selective agent and a supplement of previously described media for agrobacteria. the known biodiversity within the genus was taken into account when the selectivity of k(2)teo(3) was analyzed and its potential for isolating agrobacterium spp. directly from soil was evaluated. a k(2)teo(3) concentration of 60 ppm was found to favor the growth of agrobacteria and r ...	2001	11133429
occurrence of tn4371-related mobile elements and sequences in (chloro)biphenyl-degrading bacteria.	tn4371, a 55-kb transposable element involved in the degradation and biphenyl or 4-chlorobiphenyl identified in ralstonia eutropha a5, displays a modular structure including a phage-like integrase gene (int), a pseudomonas-like (chloro)biphenyl catabolic gene cluster (bph), and rp4- and ti-plasmid-like transfer genes (trb) (c. merlin, d. springael, and a. toussaint, plasmid 41:40-54, 1999). southern blot hybridization was used to examine the presence of different regions of tn4371 in a collectio ...	2001	11133426
complete nucleotide sequence and host range of south african cassava mosaic virus: further evidence for recombination amongst begomoviruses.	complete nucleotide sequences of the dna-a (2800 nt) and dna-b (2760 nt) components of a novel cassava-infecting begomovirus, south african cassava mosaic virus (sacmv), were determined and compared with various new world and old world begomoviruses. sacmv is most closely related to east african cassava mosaic virus (eacmv) in both its dna-a (85% with eacmv-mh and -mk) and -b (90% with eacmv-ug2-mld and eacmv-ug3-svr) components; however, percentage sequence similarities of less than 90% in the ...	2001	11125158
the role of the t-pilus in horizontal gene transfer and tumorigenesis.	the t-pilus is a flexuous filamentous appendage that is essential for agrobacterium tumefaciens virulence. t-pilus subunits are derived from a virb2-processing reaction that generates cyclized polypeptide subunits. the t-pilus filament has a diameter of 10 nm and contains a lumen approximately 2 nm in diameter. biogenesis of the t-pilus requires all 11 virb proteins, but not the vird4 protein, which is used in conjugal plasmid transfer. virb4 and virb11 are two atpases that may form homohexameri ...	2000	11121787
structure-function analysis of the tobacco mosaic virus resistance gene n.	the tobacco n gene is a member of the toll-interleukin-1 receptor/nucleotide-binding site/leucine-rich repeat (tir-nbs-lrr) class of plant resistance (r) genes and confers resistance to tobacco mosaic virus (tmv). we investigated the importance of specific domains of n in inducing tmv resistance, by examining various n deletion and point mutations that introduce single amino acid substitution mutants in vivo. our deletion analysis suggests that the tir, nbs, and lrr domains play an indispensable ...	2000	11121079
shigella flexneri luxs quorum-sensing system modulates virb expression but is not essential for virulence.	quorum-sensing systems regulate the expression of virulence factors in a wide variety of plant and animal pathogens, including members of the enterobacteriaceae. studies of shigella virulence gene expression have demonstrated that maximal expression of genes encoding the type iii secretion system and its substrates and maximal activity of this virulence organelle occur at high cell density. in these studies, we demonstrate that the expression of ipa, mxi, and spa invasion operons is maximal in s ...	2001	11119484
[study of the integral toxicity of aqueous media, polluted by petroleum and petroleum products using bacterial tests].	a biotest kit was used to assess the integral toxicity level of aquatic medium contamination with petroleum and petroleum-based products. the integral toxicity dynamics was also monitored during biodegradation of petroleum and petroleum-based products by an association of petroleum-degrading strains including acinetobacter sp., mycobacterium flavescens, and rhodococcus sp. the following bacterial tests were used: the bioluminescence (bl) test based on photobacterium leiognathi; electro-orientati ...	2000	11116909
overexpression of the arabidopsis cbf3 transcriptional activator mimics multiple biochemical changes associated with cold acclimation.	we further investigated the role of the arabidopsis cbf regulatory genes in cold acclimation, the process whereby certain plants increase in freezing tolerance upon exposure to low temperature. the cbf genes, which are rapidly induced in response to low temperature, encode transcriptional activators that control the expression of genes containing the c-repeat/dehydration responsive element dna regulatory element in their promoters. constitutive expression of either cbf1 or cbf3 (also known as dr ...	2000	11115899
regulation and function of the arabidopsis aba-insensitive4 gene in seed and abscisic acid response signaling networks.	we have characterized developmental, environmental, and genetic regulation of abscisic acid-insensitive (abi)4 gene expression in arabidopsis. although expressed most strongly in seeds, abi4 transcripts are also present at low levels in vegetative tissue; vegetative expression is not induced by abscisic acid (aba) or stress treatments. comparison of transcript levels in mature seeds of aba-insensitive, aba-hypersensitive, aba-deficient, or heterochronic mutants indicates that abi4 expression is ...	2000	11115891
the rib1 mutant is resistant to indole-3-butyric acid, an endogenous auxin in arabidopsis.	the presence of indole-3-butyric acid (iba) as an endogenous auxin in arabidopsis has been recently demonstrated. however, the in vivo role of iba remains to be elucidated. we present the characterization of a semi-dominant mutant that is affected in its response to iba, but shows a wild-type response to indole-3-acetic acid (iaa), the predominant and most studied form of auxin. we have named this mutant rib1 for resistant to iba. root elongation assays show that rib1 is specifically resistant t ...	2000	11115890
characterization of the response of the arabidopsis response regulator gene family to cytokinin.	we examined the expression of a family of arabidopsis response regulators (arr) and found that the steady-state levels of rna for most are elevated very rapidly by cytokinin. using nuclear run-on assays we demonstrated that this increase in arr transcript levels in response to cytokinin is due, at least in part, to increased transcription. the start site of transcription for the arr5 gene was identified using primer extension analysis. a dna fragment comprised of 1.6 kb upstream of the arr5 tran ...	2000	11115887
regulation of etioplast pigment-protein complexes, inner membrane architecture, and protochlorophyllide a chemical heterogeneity by light-dependent nadph:protochlorophyllide oxidoreductases a and b.	the etioplast of dark-grown angiosperms is characterized by the prolamellar body (plb) inner membrane, the absence of chlorophyll, and the accumulation of divinyl and monovinyl derivatives of protochlorophyll(ide) a [pchl(ide) a]. either of two structurally related, but differentially expressed light-dependent nadph:pchlide oxidoreductases (pors), pora and porb, can assemble the plb and form dark-stable ternary complexes containing enzymatically photoactive pchlide-f655. here we have examined in ...	2000	11115885
chloroplast division and morphology are differentially affected by overexpression of ftsz1 and ftsz2 genes in arabidopsis.	in higher plants, two nuclear gene families, ftsz1 and ftsz2, encode homologs of the bacterial protein ftsz, a key component of the prokaryotic cell division machinery. we previously demonstrated that members of both gene families are essential for plastid division, but are functionally distinct. to further explore differences between ftsz1 and ftsz2 proteins we investigated the phenotypes of transgenic plants overexpressing atftsz1-1 or atftsz2-1, arabidopsis members of the ftsz1 and ftsz2 fami ...	2000	11115884
profilin plays a role in cell elongation, cell shape maintenance, and flowering in arabidopsis.	profilin (pfn) is an ubiquitous, low-m(r), actin-binding protein involved in the organization of the cytoskeleton of eukaryotes including higher plants. pfns are encoded by a multigene family in arabidopsis. we have analyzed in vivo functions of arabidopsis pfn by generating transgenic plants carrying a 35s-pfn-1 or 35s-antisense pfn-1 transgene. etiolated seedlings underexpressing pfn (pfn-u) displayed an overall dwarf phenotype with short hypocotyls whose lengths were 20% to 25% that of wild t ...	2000	11115881
quorum sensing in vibrio fischeri: analysis of the luxr dna binding region by alanine-scanning mutagenesis.	luxr is the transcriptional activator for quorum-sensing control of luminescence in vibrio fischeri. a series of alanine-scanning mutants spanning a predicted helix-turn-helix region in the dna binding domain of luxr was constructed, and the activity of each of the luxr mutant proteins in recombinant escherichia coli was investigated. the region covered by the mutagenesis spanned residues 190 to 224. about half of the alanine-scanning mutants showed activities similar to that of the wild-type lu ...	2001	11114939
renaturation of bacillus thermoglucosidasius hrca repressor by dna and thermostability of the hrca-dna complex in vitro.	hrca, a negative control repressor for chaperone expression from the obligate thermophile bacillus thermoglucosidasius kp1006, was purified in a his-tagged form in the presence of 6 m urea but hardly renatured to an intact state due to extreme insolubility. renaturation trials revealed that the addition of dna to purified b. thermoglucosidasius hrca can result in solubilization of hrca free from the denaturing agent urea. results from band shift and light scattering assays provided three new fin ...	2001	11114912
the chvh locus of agrobacterium encodes a homologue of an elongation factor involved in protein synthesis.	the virulence of agrobacterium tumefaciens depends on both chromosome- and ti plasmid-encoded gene products. in this study, we characterize a chromosomal locus, chvh, previously identified by tnphoa mutagenesis and shown to be required for tumor formation. through dna sequencing and comparison of the sequence with identified sequences in the database, we show that this locus encodes a protein similar in sequence to elongation factor p, a protein thought to be involved in peptide bond synthesis i ...	2001	11114898
arabidopsis nac1 transduces auxin signal downstream of tir1 to promote lateral root development.	auxin plays a key role in lateral root formation, but the signaling pathway for this process is poorly understood. we show here that nac1, a new member of the nac family, is induced by auxin and mediates auxin signaling to promote lateral root development. nac1 is a transcription activator consisting of an n-terminal conserved nac-domain that binds to dna and a c-terminal activation domain. this factor activates the expression of two downstream auxin-responsive genes, dbp and air3. transgenic pl ...	2000	11114891
a novel two-component hybrid molecule regulates vascular morphogenesis of the arabidopsis root.	the developmental ontogeny of the vascular system (consisting of xylem, phloem and [pro]cambium) is poorly understood despite its central role in plant physiology. we show that in the arabidopsis root meristem, xylem cell lineages are specified early, whereas phloem and procambium are established through a set of asymmetric cell divisions. these divisions require the wooden leg (wol) gene. the wol gene encodes a novel two-component signal transducer with an unusual tandem arrangement of two rece ...	2000	11114883
an alternative cytokinin biosynthesis pathway.	studies of de novo cytokinin biosynthesis in isopentenyltransferase (ipt)-transformed arabidopsis thaliana, involving in vivo deuterium labeling and mass spectrometry, showed that the biosynthetic rate of zeatinriboside-5'-monophosphate was around 66-fold higher than that of isopentenyladenosine-5'-monophosphate (ipmp), the proposed primary product of the agrobacterium ipt. double tracer analysis, using [(2)h(6)] isopentenyladenosine and deuterium oxide, provided evidence for an alternative, ipm ...	2000	11114204
negative regulation of defense responses in plants by a conserved mapkk kinase.	the enhanced disease resistance 1 (edr1) mutation of arabidopsis confers resistance to powdery mildew disease caused by the fungus erysiphe cichoracearum. resistance mediated by the edr1 mutation is correlated with induction of several defense responses, including host cell death. double mutant analysis revealed that all edr1-associated phenotypes are suppressed by mutations that block salicylic acid (sa) perception (nim1) or reduce sa production (pad4 and eds1). the nahg transgene, which lowers ...	2001	11114160
negative regulation of defense responses in plants by a conserved mapkk kinase.	the enhanced disease resistance 1 (edr1) mutation of arabidopsis confers resistance to powdery mildew disease caused by the fungus erysiphe cichoracearum. resistance mediated by the edr1 mutation is correlated with induction of several defense responses, including host cell death. double mutant analysis revealed that all edr1-associated phenotypes are suppressed by mutations that block salicylic acid (sa) perception (nim1) or reduce sa production (pad4 and eds1). the nahg transgene, which lowers ...	2001	11114160
[sterilization of phacoemulsification and vitrectomy instruments. contamination and evaluation].	contamination of automated surgical equipment is widely disregarded as a potential source of perioperative infection. we investigated the possibility of contamination of the aspiration fluid by the vacuum control manifold (vcm). the normal, unsterile internal vcm was compared with a modified external vcm that was regularly disinfected.	2000	11105548
virulence factors of helicobacter pylori responsible for gastric diseases in mongolian gerbil.	helicobacter pylori infection induces various gastroduodenal diseases. we examined the role of two genes, vaca and cage, in the gastric pathogenesis induced by h. pylori using a long-term (62 wk) animal model. reportedly, both genes are associated with the virulence of h. pylori: vaca encodes vacuolating cytotoxin, and cage, with other genes in the cag pathogenicity islands, encodes a type iv secretion system. mongolian gerbils were challenged in this study by a wild-type tn2 strain and its isog ...	2000	11104802
overexpression of mitochondrial citrate synthase in arabidopsis thaliana improved growth on a phosphorus-limited soil.	the gene for mitochondrial citrate synthase (cs) was isolated from daucus carota (dccs) and introduced into arabidopsis thaliana (strain ws) using agrobacterium tumefaciens-mediated transformation. characteristics of citrate excretion were compared between t3 transgenic plants, which were derived from the initial transgenic plants by self-fertilization and homozygous for dccs, and the control plants that had no dccs. the highest cs activity 0.78 micromol protein min(-1) exhibited by the transgen ...	2000	11100775
control of expression of divergent pseudomonas putida put promoters for proline catabolism.	pseudomonas putida kt2440 uses proline as the sole c and n source. utilization of this amino acid involves its uptake, which is mediated by the putp protein, and its conversion into glutamate, mediated by the puta protein. sequence analysis revealed that the puta and putp genes are transcribed divergently. expression from the putp and puta genes was analyzed at the mrna level in different host backgrounds in the absence and presence of proline. expression from the put promoters was induced by pr ...	2000	11097893
novel approaches to oral vaccines: delivery of antigens by edible plants.	advances in genetic engineering in the past decade have accelerated the expression, in plants, of foreign proteins with industrial and pharmaceutical value. antigens from infectious bacterial or viral diseases have been introduced into plants through plant virus-mediated infection or agrobacterium tumefaciens-mediated stable transformation methods. oral immunization with transgenic plant tissues that contain vaccine antigen proteins stimulates both systemic and mucosal immune responses in animal ...	2000	11095841
molecular evolution of virulence in natural field strains of xanthomonas campestris pv. vesicatoria.	the avrbs2 avirulence gene of the bacterial plant pathogen xanthomonas campestris pv. vesicatoria triggers disease resistance in pepper plants containing the bs2 resistance gene and contributes to bacterial virulence on susceptible host plants. we studied the effects of the pepper bs2 gene on the evolution of avrbs2 by characterizing the molecular basis for virulence of 20 x. campestris pv. vesicatoria field strains that were isolated from disease spots on previously resistant bs2 pepper plants. ...	2000	11092868
transcriptional control of the hydrogen cyanide biosynthetic genes hcnabc by the anaerobic regulator anr and the quorum-sensing regulators lasr and rhlr in pseudomonas aeruginosa.	virulence factors of pseudomonas aeruginosa include hydrogen cyanide (hcn). this secondary metabolite is maximally produced at low oxygen tension and high cell densities during the transition from exponential to stationary growth phase. the hcnabc genes encoding hcn synthase were identified on a genomic fragment complementing an hcn-deficient mutant of p. aeruginosa pao1. the hcna promoter was found to be controlled by the fnr-like anaerobic regulator anr and by the quorum-sensing regulators las ...	2000	11092854
evidence for horizontal gene transfer in evolution of elongation factor tu in enterococci.	the elongation factor tu, encoded by tuf genes, is a gtp binding protein that plays a central role in protein synthesis. one to three tuf genes per genome are present, depending on the bacterial species. most low-g+c-content gram-positive bacteria carry only one tuf gene. we have designed degenerate pcr primers derived from consensus sequences of the tuf gene to amplify partial tuf sequences from 17 enterococcal species and other phylogenetically related species. the amplified dna fragments were ...	2000	11092850
a rab1 gtpase is required for transport between the endoplasmic reticulum and golgi apparatus and for normal golgi movement in plants.	we describe a green fluorescent protein (gfp)-based assay for investigating membrane traffic on the secretory pathway in plants. expression of atrab1b(n121i), predicted to be a dominant inhibitory mutant of the arabidopsis rab gtpase atrab1b, resulted in accumulation of a secreted gfp marker in an intracellular reticulate compartment reminiscent of the endoplasmic reticulum. this accumulation was alleviated by coexpressing wild-type atrab1b but not atrab8c. when a golgi-targeted and n-glycosylat ...	2000	11090219
tobacco vdl gene encodes a plastid dead box rna helicase and is involved in chloroplast differentiation and plant morphogenesis.	the recessive nuclear vdl (for variegated and distorted leaf) mutant of tobacco was obtained by t-dna insertion and characterized by variegated leaves and abnormal roots and flowers. affected leaf tissues were white and distorted, lacked palisadic cells, and contained undifferentiated plastids. the variegation was due to phenotypic, rather than genetic, instability. genomic and cdna clones were obtained for both the mutant and wild-type vdl alleles. three transcripts, resulting from alternate in ...	2000	11090214
ta single amino acid difference distinguishes resistant and susceptible alleles of the rice blast resistance gene pi-ta.	the rice blast resistance (r) gene pi-ta mediates gene-for-gene resistance against strains of the fungus magnaporthe grisea that express avirulent alleles of avr-pita. using a map-based cloning strategy, we cloned pi-ta, which is linked to the centromere of chromosome 12. pi-ta encodes a predicted 928-amino acid cytoplasmic receptor with a centrally localized nucleotide binding site. a single-copy gene, pi-ta shows low constitutive expression in both resistant and susceptible rice. susceptible r ...	2000	11090207
a telomeric avirulence gene determines efficacy for the rice blast resistance gene pi-ta.	genetic mapping showed that the rice blast avirulence gene avr-pita is tightly linked to a telomere on chromosome 3 in the plant pathogenic fungus magnaporthe grisea. avr-pita corresponds in gene-for-gene fashion to the disease resistance (r) gene pi-ta. analysis of spontaneous avr-pita(-) mutants indicated that the gene is located in a telomeric 6.5-kb bglii restriction fragment. cloning and dna sequencing led to the identification of a candidate gene with features typical of metalloproteases. ...	2000	11090206
mutants of arabidopsis defective in a sequence-specific mrna degradation pathway.	one of the ways a cell can rapidly and tightly regulate gene expression is to target specific mrnas for rapid decay. a number of mrna instability sequences that mediate rapid mrna decay have been identified, particularly from multicellular eukaryotes, but pinpointing the cellular components that play critical roles in sequence-specific decay in vivo has been more difficult. in contrast, general pathways of mrna degradation in yeast have been well established through the analysis of mutants affec ...	2000	11087822
transgenic apple (malus x domestica) shoot showing low browning potential.	transgenic apple shoots were prepared from leaf disks by using agrobacterium tumefaciens carrying the kanamycin (km) resistance gene and antisense polyphenol oxidase (ppo) dna. four transgenic apple lines that grew on the medium containing 50 microgram/ml km were obtained. they contained the km resistance gene and grew stably on the medium for >3 years. two transgenic shoot lines containing antisense ppo dna in which ppo activity was repressed showed a lower browning potential than a control sho ...	2000	11087467
fbpabc gene cluster in neisseria meningitidis is transcribed as an operon.	the neisserial fbpabc locus has been proposed to constitute a single transcriptional unit. to confirm this operonic arrangement, transcription assays using reverse transcriptase pcr amplification were conducted with neisseria meningitidis. the presence of fbpab and fbpbc transcripts obtained by priming cdna synthesis with an fbpc-sequence-specific oligonucleotide indicates that fbpabc is organized as a single expression unit. the ratio of fbpa to fbpabc mrna was approximately between 10- to 20-f ...	2000	11083849
dna sequence and comparison of virulence plasmids from rhodococcus equi atcc 33701 and 103.	the virulence plasmids of the equine virulent strains rhodococcus equi atcc 33701 and 103 were sequenced, and their genetic structure was analyzed. p33701 was 80,610 bp in length, and p103 was 1 bp shorter; their sequences were virtually identical. the plasmids contained 64 open reading frames (orfs), 22 of which were homologous with genes of known function and 3 of which were homologous with putative genes of unknown function in other species. putative functions were assigned to five orfs based ...	2000	11083803
regulation of the porphyromonas gingivalis fima (fimbrillin) gene.	in common with many bacterial virulence genes, the fimbrillin (fima) gene of porphyromonas gingivalis is modulated in response to environmental fluctuation. the trans-acting components that comprise the regulatory system for transcriptional activity of the fima gene in p. gingivalis were investigated. three major proteins were found to bind to the upstream region of the fima promoter. one of these proteins was fimbrillin itself, and the other two were a major arginine protease (rgp) and lysine p ...	2000	11083767
overexpression of auxin-binding protein enhances the sensitivity of guard cells to auxin.	to explore the role of auxin-binding protein (abp1) in planta, a number of transgenic tobacco (nicotiana tabacum) lines were generated. the wild-type kdel endoplasmic reticulum targeting signal was mutated to hdel, another common retention sequence in plants, and to keql or kdelgl to compromise its activity. the auxin-binding kinetics of these forms of abp1 were found to be similar to those of abp1 purified from maize (zea mays). to test for a physiological response mediated by auxin, intact gua ...	2000	11080299
antisense inhibition of the nr gene restores normal ripening to the tomato never-ripe mutant, consistent with the ethylene receptor-inhibition model.	the hormone ethylene regulates many aspects of plant growth and development, including fruit ripening. in transgenic tomato (lycopersicon esculentum) plants, antisense inhibition of ethylene biosynthetic genes results in inhibited or delayed ripening. the dominant tomato mutant, never-ripe (nr), is insensitive to ethylene and fruit fail to ripen. the nr phenotype results from mutation of the ethylene receptor encoded by the nr gene, such that it can no longer bind the hormone. nr has homology to ...	2000	11080285