| atkup1: an arabidopsis gene encoding high-affinity potassium transport activity. | because plants grow under many different types of soil and environmental conditions, we investigated the hypothesis that multiple pathways for k+ uptake exist in plants. we have identified a new family of potassium transporters from arabidopsis by searching for homologous sequences among the expressed sequence tags of the genbank database. the deduced amino acid sequences of atkup (for arabidopsis thaliana k+ uptake transporter) cdnas are highly homologous to the non-plant kup and hak1 potassium ... | 1998 | 9477571 |
| atkup1: a dual-affinity k+ transporter from arabidopsis. | plant roots contain both high- and low-affinity transport systems for uptake of k+ from the soil. in this study, we characterize a k+ transporter that functions in both high- and low-affinity uptake. using yeast complementation analysis, we isolated a cdna for a functional k+ transporter from arabidopsis (referred to as atkup1 for arabidopsis thaliana k+ uptake). when expressed in a yeast mutant, atkup1 dramatically increased k+ uptake capacity at both a low and high [k+] range. kinetic analyses ... | 1998 | 9477572 |
| analysis of t-dna-mediated translational beta-glucuronidase gene fusions. | three random translational beta-glucuronidase (gus) gene fusions were previously obtained in arabidopsis thaliana, using agrobacterium-mediated transfer of a gus coding sequence without promoter and atg initiation site. these were analysed by ipcr amplification of the sequence upstream of gus and nucleotide sequence analysis. in one instance, the gus sequence was fused, in inverse orientation, to the nos promoter sequence of a truncated tandem t-dna copy and translated from a spurious atg in thi ... | 1998 | 9484433 |
| analysis of the isopentenyl diphosphate isomerase gene family from arabidopsis thaliana. | two arabidopsis thaliana cdnas (ipp1 and ipp2) encoding isopentenyl diphosphate isomerase (ipp isomerase) were isolated by complementation of an ipp isomerase mutant strain of saccharomyces cerevisiae. both cdnas encode enzymes with an amino terminus that may function as a transit peptide for localization in plastids. at least 31 amino acids from the amino terminus of the ipp1 protein and 56 amino acids from the amino terminus of the ipp2 protein are not essential for enzymatic activity. genomic ... | 1998 | 9484444 |
| soluble, highly fluorescent variants of green fluorescent protein (gfp) for use in higher plants. | green fluorescent protein (gfp) from aequorea victoria has rapidly become a standard reporter in many biological systems. however, the use of gfp in higher plants has been limited by aberrant splicing of the corresponding mrna and by protein insolubility. it has been shown that gfp can be expressed in arabidopsis thaliana after altering the codon usage in the region that is incorrectly spliced, but the fluorescence signal is weak, possibly due to aggregation of the encoded protein. through site- ... | 1998 | 9484447 |
| molecular cloning of a novel fimbrin-like cdna from arabidopsis thaliana. | fimbrin is a 68-70 kda actin-bundling protein in animal cells and lower eukaryotes that participates in diverse morphogenetic processes by cross-linking actin filaments into bundles. here we report the cloning by degenerate polymerase chain reaction (pcr) of atfim1, a 2.3 kb cdna from arabidopsis thaliana that codes for a novel 76 kda fimbrin-like polypeptide (atfim1). the predicted sequence of atfim1 shares ca. 40% identity with nonplant fimbrins and contains two tandem repeats, each possessing ... | 1998 | 9484459 |
| structural analysis of the nit2/nit1/nit3 gene cluster encoding nitrilases, enzymes catalyzing the terminal activation step in indole-acetic acid biosynthesis in arabidopsis thaliana. | a 13.8 kb dna sequence containing the promoters and the structural genes of the arabidopsis thaliana nit2/nit1/nit3 gene cluster has been isolated and characterized. the coding regions of nit2, nit1 and nit3 spanned 1.9, 1.8 and 2.1 kb, respectively. the architecture of the three genes is highly conserved. each isoform consists of five exons separated by four introns. the introns are very similar with respect to size and position, but differ considerably in sequence composition. in contrast to t ... | 1998 | 9484465 |
| the arabidopsis aux1 gene: a model system to study mrna processing in plants. | it is advantageous for an organism to be able to remove aberrant mrnas that have either been incorrectly transcribed or processed in order to prevent the accumulation of potentially harmful proteins. the selective degradation of nonsense containing transcripts has been described in yeast. caenorhabditis elegans and plants. the ease of identification of new mutant alleles in the aux1 gene of arabidopsis thaliana has provided a useful system to study novel mutations affecting mrna stability and pr ... | 1998 | 9484486 |
| prha controls a novel regulatory pathway required for the specific induction of ralstonia solanacearum hrp genes in the presence of plant cells. | the ralstonia solanacearum hrp gene cluster is organized in five transcriptional units. expression of transcriptional units 2, 3 and 4 is induced in minimal medium and depends on the hrp regulatory gene hrpb, which belongs to unit 1. this regulatory gene also controls the expression of genes, such as popa, located to the left of the hrp cluster. here, we show that, upon co-culture with arabidopsis thaliana and tomato cell suspensions, the expression of the hrp transcriptional units 1, 2, 3 and 4 ... | 1998 | 9484898 |
| self-sufficient biosynthesis of pregnenolone and progesterone in engineered yeast. | the first two steps of the steroidogenic pathway were reproduced in saccharomyces cerevisiae. engineering of sterol biosynthesis by disruption of the delta 22-desaturase gene and introduction of the arabidopsis thaliana delta 7-reductase activity and coexpression of bovine side chain cleavage cytochrome p450, adrenodoxin, and adrenodoxin reductase, lead to pregnenolone biosynthesis from a simple carbon source. following additional coexpression of human 3 beta-hydroxysteroid dehydrogenase/isomera ... | 1998 | 9487528 |
| alteration of hormone levels in transgenic tobacco plants overexpressing the rice homeobox gene osh1. | the rice (oryza sativa l.) homeobox gene osh1 causes morphological alterations when ectopically expressed in transgenic rice, arabidopsis thaliana, and tobacco (nicotiana tabacum l.) and is therefore believed to function as a morphological regulator gene. to determine the relationship between osh1 expression and morphological alterations, we analyzed the changes in hormone levels in transgenic tobacco plants exhibiting abnormal morphology. levels of the plant hormones indole-3-acetic acid, absci ... | 1998 | 9489007 |
| chimeric arabidopsis thaliana ribulose-1,5-bisphosphate carboxylase/oxygenase containing a pea small subunit protein is compromised in carbamylation. | a cdna of pea (pisum sativum l.) rbcs 3a, encoding a small subunit protein (s) of ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco), has been expressed in arabidopsis thaliana under control of the cauliflower mosaic virus 35s promoter, and the transcript and mature s protein were detected. specific antibodies revealed two protein spots for the four arabidopsis s and one additional spot for pea s. pea s in chimeric rubisco amounted to 15 to 18% of all s, as judged by separation on two-dim ... | 1998 | 9489016 |
| cloning of a tobacco apoplasmic invertase inhibitor. proof of function of the recombinant protein and expression analysis during plant development. | higher plants express several isoforms of vacuolar and cell wall invertases (cwi), some of which are inactivated by inhibitory proteins at certain stages of plant development. we have purified an apoplasmic inhibitor (inh) of tobacco (nicotiana tabacum) cwi to homogeneity. based on sequences from tryptic fragments, we have isolated a full-length inh-encoding cdna clone (nt-inh1) via a reverse transcriptase-polymerase chain reaction. southern-blot analysis revealed that inh is encoded by a single ... | 1998 | 9489020 |
| metabolic compartmentation of plastid prenyllipid biosynthesis--evidence for the involvement of a multifunctional geranylgeranyl reductase. | the addition of phytyl side chain to chlorophylls, tocopherols and phylloquinone is prerequisite to their integration into plastid membranes. we have cloned a cdna encoding a pre-geranylgeranyl reductase from arabidopsis thaliana. the deduced primary structure predicts a mature size with a molecular mass of 47 kda and displays a characteristic dinucleotide binding domain. geranylgeranyl reductase expressed in escherichia coli sequentially catalyzes the reduction of geranylgeranyl-chlorophyll a i ... | 1998 | 9492312 |
| cyp86a1 from arabidopsis thaliana encodes a cytochrome p450-dependent fatty acid omega-hydroxylase. | the a. thaliana est database was screened using consensus motifs derived from p450 families cyp52 and cyp4 catalyzing the omega-hydroxylation of fatty acids and alkanes in candida and in mammals. one est cdna fragment was detected in this way and the corresponding full-length cdna was cloned from a cdna library of a. thaliana. this cdna coded the first member of a new plant p450 family and was termed cyp86a1. the deduced peptide sequence showed highest homology with p450s from families 4 and 52. ... | 1998 | 9500987 |
| the transposition frequency of tag1 elements is increased in transgenic arabidopsis lines. | tag1 was identified as a highly active endogenous transposable element in transgenic arabidopsis thaliana landsberg erecta plants carrying the maize transposable element activator (ac). here, we describe experiments designed to determine the basis for the high activity of tag1. the frequency of transposition of tag1 elements was compared in lines containing or lacking ac transposase to assess the effect of ac transposase on tag1 activity. three populations of nontransgenic plants, including nont ... | 1998 | 9501115 |
| characterization of skt1, an inwardly rectifying potassium channel from potato, by heterologous expression in insect cells. | a cdna encoding a novel, inwardly rectifying k+ (k+in) channel protein, skt1, was cloned from potato (solanum tuberosum l.). skt1 is related to members of the akt family of k+in channels previously identified in arabidopsis thaliana and potato. skt1 mrna is most strongly expressed in leaf epidermal fragments and in roots. in electrophysiological, whole-cell, patch-clamp measurements performed on baculovirus-infected insect (spodoptera frugiperda) cells, skt1 was identified as a k+in channel that ... | 1998 | 9501121 |
| an embryo-defective mutant of arabidopsis disrupted in the final step of biotin synthesis | auxotrophic mutants have played an important role in the genetic dissection of biosynthetic pathways in microorganisms. equivalent mutants have been more difficult to identify in plants. the bio1 auxotroph of arabidopsis thaliana was shown previously to be defective in the synthesis of the biotin precursor 7, 8-diaminopelargonic acid. a second biotin auxotroph of a. thaliana has now been identified. arrested embryos from this bio2 mutant are defective in the final step of biotin synthesis, the c ... | 1998 | 9501126 |
| the chloroplast small heat-shock protein oligomer is not phosphorylated and does not dissociate during heat stress in vivo. | plants synthesize several classes of small (15- to 30-kd monomer) heat-shock proteins (shsps) in response to heat stress, including a nuclear-encoded, chloroplast-localized shsp (hsp21). cytosolic shsps exist as large oligomers (approximately 200-800 kd) composed solely or primarily of shsps. phosphorylation of mammalian shsps causes oligomer dissociation, which appears to be important for regulation of shsp function. we examined the native structure and phosphorylation of chloroplast hsp21 to u ... | 1998 | 9501148 |
| in vivo functional discrimination between plant thioredoxins by heterologous expression in the yeast saccharomyces cerevisiae. | whereas vertebrates possess only two thioredoxin genes, higher plants present a much greater diversity of thioredoxins. for example, arabidopsis thaliana has five cytoplasmic thioredoxins (type h) and at least as many chloroplastic thioredoxins. the abundance of plant thioredoxins leads to the question whether the various plant thioredoxins play a similar role or have specific functions. because most of these proteins display very similar activities on artificial or biological substrates in vitr ... | 1998 | 9501259 |
| cell morphogenesis in arabidopsis. | cell morphogenesis encompasses all processes required to establish a three-dimensional cell shape. cells acquire the architecture specific to their developmental context by using the spatial information provided by internal or external cues. as a response to these signals, cells become reorganized and establish functionally distinct subcellular domains that ultimately lead to morphological changes. in its simplest form, cell morphogenesis results in the establishment of asymmetry along one axis, ... | 1998 | 9504044 |
| roles of conserved residues in the arginase family. | arginases and related enzymes metabolize arginine or similar nitrogen-containing compounds to urea or formamide. in the present report a sequence alignment of 31 members of this family was generated. the alignment, together with the crystal structure of rat liver arginase, allowed the assignment of possible functional or structural roles to 32 conserved residues and conservative substitutions. two of these residues were previously identified as functionally essential by analysis of inherited def ... | 1998 | 9507056 |
| an arabidopsis cdna encodes an apparent polyprotein of two non-identical thylakoid membrane proteins that are associated with photosystem ii and homologous to algal ycf32 open reading frames. | we have characterised an arabidopsis thaliana cdna homologous to the ycf32 open reading frames present in the synechocystis genome and the plastid genomes of several eukaryotic algae. the predicted protein is also homologous to a novel protein reported to be associated with photosystem ii. the protein is synthesised as a 23 kda precursor with an n-terminal presequence that appears to be bipartite in structure, and the protein is targeted into the thylakoid membrane of pea chloroplasts. although ... | 1998 | 9512354 |
| molecular cloning and characterization of the gene encoding glutathione reductase in brassica campestris. | we have isolated the brassica campestris cdna encoding glutathione reductase of 502 amino acid residues with molecular mass of 54.5 kda. the deduced amino acid sequences were 92.2%, and 79.5% identical to those of arabidopsis thaliana, and pea, respectively. as expected, it exhibited a high degree of conservation within the region responsible for the redox reaction and for the binding of gssg or nadph. the gene was highly inducible by ozone fumigation or by paraquat treatment. | 1998 | 9512665 |
| molecular cloning of plant spermidine synthases. | four cdnas for spermidine synthase (spds), which converts the diamine putrescine to the higher polyamine spermidine using decarboxylated s-adenosylmethionine as the co-factor, were isolated from nicotiana sylvestris, hyoscyamus niger, and arabidopsis thaliana. when the n.sylvestris spds cdna was expressed in a spds-deficient e. coli mutant, the recombinant protein showed high spds activity, but did not have any spermine synthase activity. the plant spdss have molecular masses of about 34 kda, po ... | 1998 | 9517003 |
| the influences of two plant nuclear matrix attachment regions (mars) on gene expression in transgenic plants. | nuclear matrix attachment regions (mars) are thought to influence gene expression by anchoring active chromatin to the proteinaceous nuclear matrix. in this study, two plant dna fragments with strong mar activity were selected and tested for their effects on expression of a linked reporter gene in transgenic tobacco. one mar was isolated from the 5' flanking region of a pea vicilin gene previously reported to be expressed in a copy number-dependent manner in transgenic tobacco. a second mar was ... | 1998 | 9517008 |
| isolation and characterisation of the rad51 and dmc1 homologs from arabidopsis thaliana. | by using rt-pcr and degenerate oligonucleotides based on the sequence homology between the yeast rad51 and dmc1 genes, two genes belonging to the rad51 and dmc1 families were isolated from arabidopsis thaliana ecotype columbia. a rad51 genomic dna was also sequenced which is almost identical to its landsberg erecta counterpart, except for a few translationally silent substitutions and for the presence of a 527-bp element downstream of the polyadenylation site. this element is repeated in the gen ... | 1998 | 9520262 |
| the yeast clc chloride channel functions in cation homeostasis. | a defect in the yeast gef1 gene, a clc chloride channel homolog leads to an iron requirement and cation sensitivity. the iron requirement is due to a failure to load cu2+ onto a component of the iron uptake system, fet3. this process, which requires both gef1 and the menkes disease cu2+-atpase yeast homolog ccc2, occurs in late- or post-golgi vesicles, where gef1 and ccc2 are localized. the defects of gef1 mutants can be suppressed by the introduction of torpedo marmorata clc-0 or arabidopsis th ... | 1998 | 9520490 |
| molecular cloning and characterization of two phosphatase 2a catalytic subunit genes from arabidopsis thaliana. | the plant arabidopsis thaliana contains five isoforms of the catalytic subunit of protein phosphatase 2a (pp2a) that can be grouped into two families, one composed by isoforms pp2a-1, -2 and -5 and the other composed by isoforms pp2a-3 and pp2a-4. an arabidopsis genomic library was screened and several clones corresponding to genes pp2a-3 and pp2a-4 were isolated and analysed. both genes span over approximately 4.5kbp and are composed of 11 exons and 10 introns that show identical organization. ... | 1998 | 9524239 |
| cloning of a cdna from arabidopsis thaliana homologous to the human xpb gene. | the human gene xpb, defective in xeroderma pigmentosum patients complementation group b, encodes a dna helicase involved in several dna metabolic pathways, including dna repair and transcription. the high conservation of this gene has allowed the cloning of homologs in various species, such as mouse, yeast and drosophila. not much information on the molecular basis of nucleotide excision repair in plants is available, but these organisms may have similar mechanisms to other eukaryotes. a homolog ... | 1998 | 9524267 |
| high-level expression of a viscotoxin in arabidopsis thaliana gives enhanced resistance against plasmodiophora brassicae. | viscotoxins are a group of toxic thionins found in several mistletoe species. the constitutive camv-omega promoter was used to drive the expression of the viscotoxin a3 cdna from viscum album in transgenic arabidopsis thaliana c24. lines with high viscotoxin a3 levels in all parts of the plant were selected and tested for resistance against the clubroot pathogen plasmodiophora brassicae. the transgenic lines were more resistant to infection by this pathogen than the parental line. | 1998 | 9526499 |
| nad(+)-dependent isocitrate dehydrogenase from arabidopsis thaliana. characterization of two closely related subunits. | two cdna clones which appear to encode different subunits of nad(+)-dependent isocitrate dehydrogenase (idh; ec 1.1.1.41) were identified by homology searches from the arabidopsis est database. these cdna clones were obtained and sequenced; both encoded full-length messages and displayed 82.7% nucleotide sequence identity over the coding region. the deduced amino acid sequences revealed preprotein lengths of 367 residues, with an amino acid identity of 86.1%. genomic southern blot analysis showe ... | 1998 | 9526501 |
| a heat-sensitive arabidopsis thaliana kinase substitutes for human p70s6k function in vivo. | in mammalian cells, mitogen-induced phosphorylation of ribosomal protein s6 by p70s6k has been implicated in the selective translational upregulation of 5'top mrnas. we demonstrate here that the homologous arabidopsis thaliana protein, ats6k2, ectopically expressed in human 293 cells or isolated from plant cells, phosphorylates specifically mammalian and plant s6 at 25 degrees c but not at 37 degrees c. when arabidopsis suspension culture cells are shifted from 25 to 37 degrees c, the kinase bec ... | 1998 | 9528776 |
| tonoplast intrinsic proteins from cauliflower (brassica oleracea l. var. botrytis): immunological analysis, cdna cloning and evidence for expression in meristematic tissues. | the vacuolar membrane (tonoplast) of plant cells contains aquaporins, protein channels that facilitate the selective transport of water. these tonoplast intrinsic proteins (tips) of 23-29 kda belong to the ancient major intrinsic protein (mip) family. a monospecific polyclonal antiserum directed against a 26 kda intrinsic protein from the tonoplast of meristematic cells from cauliflower (brassica oleracea l. var. botrytis) was used to screen a cdna library. two distinct cdnas have been isolated. ... | 1998 | 9530877 |
| arabidopsis skp1, a homologue of a cell cycle regulator gene, is predominantly expressed in meristematic cells. | the yeast skp1 gene and its human homolog p19skp1 encode a kinetochore protein required for cell cycle progression at both the dna synthesis and mitosis phases of the cell cycle. in orchids we identified a cdna (o 108) that is expressed in early stages of ovule development and is homologous to the yeast skp1. based on the orchid o 108 cdna clone, we identified and characterized an arabidopsis thaliana (l.) heynh. cdna designated atskp1 that also has high sequence similarity to yeast skp1. the ar ... | 1998 | 9530878 |
| cystathionine gamma-synthase from arabidopsis thaliana: purification and biochemical characterization of the recombinant enzyme overexpressed in escherichia coli. | cystathionine gamma-synthase catalyses the first reaction specific for methionine biosynthesis in plants, the gamma-replacement of the phosphoryl substituent of o-phosphohomoserine by cysteine. a cdna encoding cystathionine gamma-synthase from arabidopsis thaliana has been cloned and used to overexpress the enzyme in escherichia coli. the native recombinant enzyme is a homotetramer composed of 53 kda subunits, each being tightly associated with one molecule of pyridoxal 5'-phosphate that binds a ... | 1998 | 9531508 |
| recombinant expression, purification, and characterization of three isoenzymes of aspartate aminotransferase from arabidopsis thaliana. | five different genes encoding isoenzymes of aspartate aminotransferase (aat) have been identified in the plant arabidopsis thaliana. cdna sequences encoding three of these aat isoenzymes, asp1 (mitochondrial), asp2 (cytosolic), and asp5 (plastid), were manipulated into bacterial expression vectors and the recombinant proteins expressed were purified from liquid culture using conventional methods. yields of the purified isoenzymes varied from 11.5 mg/g wet wt cells (aat5) to 0.95 mg/g wet wt cell ... | 1998 | 9535706 |
| the ga2 locus of arabidopsis thaliana encodes ent-kaurene synthase of gibberellin biosynthesis. | the ga2 mutant of arabidopsis thaliana is a gibberellin-deficient dwarf. previous biochemical studies have suggested that the ga2 mutant is impaired in the conversion of copalyl diphosphate to ent-kaurene, which is catalyzed by ent-kaurene synthase (ks). overexpression of the previously isolated ks cdna from pumpkin (cucurbita maxima) (cmks) in the ga2 mutant was able to complement the mutant phenotype. a genomic clone coding for ks, atks, was isolated from a. thaliana using cmks cdna as a heter ... | 1998 | 9536043 |
| effect of atp sulfurylase overexpression in bright yellow 2 tobacco cells. regulation of atp sulfurylase and so4(2-) transport activities. | to determine if the atp sulfurylase reaction is a regulatory step for the so4(2-)-assimilation pathway in plants, an arabidopsis thaliana atp sulfurylase cdna, aps2, was fused to the 35s promoter of the cauliflower mosaic virus and introduced by agrobacterium tumefaciens-mediated transformation into isolated bright yellow 2 tobacco (nicotiana tabacum) cells. the atp sulfurylase activity in transgenic cells was 8-fold that in control cells, and was correlated with the expression of a specific pol ... | 1998 | 9536047 |
| cloning and characterization of atrgp1. a reversibly autoglycosylated arabidopsis protein implicated in cell wall biosynthesis. | a reversibly glycosylated polypeptide from pea (pisum sativum) is thought to have a role in the biosynthesis of hemicellulosic polysaccharides. we have investigated this hypothesis by isolating a cdna clone encoding a homolog of arabidopsis thaliana, reversibly glycosylated polypeptide-1 (atrgp1), and preparing antibodies against the protein encoded by this gene. polyclonal antibodies detect homologs in both dicot and monocot species. the patterns of expression and intracellular localization of ... | 1998 | 9536051 |
| characterization of a gene for spinach cap160 and expression of two spinach cold-acclimation proteins in tobacco. | the cdna sequence for cap160, an acidic protein previously linked with cold acclimation in spinach (spinacia oleracea l.), was characterized and found to encode a novel acidic protein of 780 amino acids having very limited homology to a pair of arabidopsis thaliana stress-regulated proteins, rd29a and rd29b. the lack of similarity in the structural organization of the spinach and arabidopsis genes highlights the absence of a high degree of conservation of this cold-stress gene across taxonomic b ... | 1998 | 9536054 |
| cloning and characterization of the human rna polymerase i subunit hrpa40. | the cloning of the human rna polymerase i 40 kda subunit, and the comparison of its amino acid sequence to other related rna polymerase subunits are described. the amino acid sequence of hrpa40 has high homology to the mouse rna polymerase i 40 kda subunit (93%), to two arabidopsis thaliana subunits (47%), the yeast rpc40 subunit (46%) and the human rna polymerase ii hrpb33 subunit (40%). southern blot analysis shows that this gene is single copy and northern blot analysis indicates that the mrn ... | 1998 | 9540830 |
| expression of a plastidic atp/adp transporter gene in escherichia coli leads to a functional adenine nucleotide transport system in the bacterial cytoplasmic membrane. | recently, a second type of eucaryotic adenine nucleotide transporter located in the inner envelope membrane of higher plants has been identified at the molecular level (neuhaus, h. e., thom, e., möhlmann, t., steup, m., and kampfenkel, k. (1997) plant j. 11, 73-82). here we have analyzed the biochemical properties of this atp/adp transporter from arabidopsis thaliana (aatp1, at). this analysis was carried out by expressing a cdna encoding this carrier as a histidine-tagged chimeric protein heter ... | 1998 | 9545295 |
| interaction of quinones with arabidopsis thaliana thioredoxin reductase. | in view of the ubiquitous role of the thioredoxin/thioredoxin reductase (trx/tr) system in living cells, the interaction of arabidopsis thaliana nadph-thioredoxin reductase (ec 1.6.4.5) with quinones, an important class of redox cycling and alkylating xenobiotics, was studied. the steady-state reactions of a. thaliana tr with thioredoxin (trx) and reaction product nadp+ inhibition patterns were in agreement with a proposed model of e. coli enzyme (b.w. lennon, c.h. williams, jr., biochemistry, v ... | 1998 | 9546049 |
| occurrence of two plastidic atp/adp transporters in arabidopsis thaliana l.--molecular characterisation and comparative structural analysis of similar atp/adp translocators from plastids and rickettsia prowazekii. | recently, we sequenced a cdna clone from arabidopsis thaliana l. encoding an atp/adp transporter protein (aatp1) located in the plastid envelope membrane. the deduced amino acid sequence of aatp1 exhibits a high degree of similarity (> 66%) to the atp/adp transporter from the obligate intracellular gram-negative bacterium rickettsia prowazekii. here we report a second plastidic atp/adp carrier from a. thaliana (aatp2). as deduced from the amino acid sequence, aatp2 exhibits 77.6% identity to aat ... | 1998 | 9546649 |
| detection of abscisic-acid-binding proteins in the microsomal protein fraction of arabidopsis thaliana with abscisic-acid-protein conjugates used as affinity probes. | a family of affinity probes has been generated to detect and purify abscisic-acid (aba)-binding proteins, by coupling aba onto carrier proteins (ovalbumin or bsa) through the c1 carboxyl group or the c4' carbonyl group of aba. elisa detection showed that these aba-protein conjugates bound efficiently to the solubilized microsomal protein fraction of arabidopsis thaliana, but not to the soluble protein fraction. heat or proteolytic treatments inhibited the binding of the conjugates, indicating th ... | 1998 | 9546653 |
| collinearity between a 30-centimorgan segment of arabidopsis thaliana chromosome 4 and duplicated regions within the brassica napus genome. | arabidopsis thaliana (the model dicotyledonous plant) is closely related to brassica crop species. genome collinearity, or conservation of marker order, between brassica napus (oilseed rape) and a. thaliana was assessed over a 7.5-mbp region of the long arm of a. thaliana chromosome 4, equivalent to 30 cm. estimates of copy number indicated that sequences present in a single copy in the haploid genome of a. thaliana (n = 5) were present in 2-8 copies in the haploid genome of b. napus (n = 19), w ... | 1998 | 9549059 |
| a novel arabidopsis thaliana protein protects tumor cells from tumor necrosis factor-induced apoptosis. | recently we have cloned and characterized a novel, oxidative stress-induced arabidopsis thaliana gene (oxy5), and showed that expression of oxy5 protects bacterial cells from death caused by oxidative stress. as oxidative stress is one pathway of tnf cytotoxicity, we investigated whether the encoded protein could also protect human tumor cells from tnf killing. we stably transfected the oxy5 gene into tnf-sensitive hela d98 cells (d98/o.5), and found that all examined transfectants were highly t ... | 1998 | 9551087 |
| identification and characterization of a novel cap-binding protein from arabidopsis thaliana. | cap-binding proteins specifically bind to the 7-methyl guanosine (m7g) functional group at the 5' end of eukaryotic mrnas. a novel arabidopsis thaliana protein has been identified that has sequence similarity to cap-binding proteins but is clearly a different form of the protein. the most obvious primary sequence difference is the substitution of two of the eight conserved tryptophan residues with other aromatic amino acids in the novel protein. analogous forms of this novel protein appear to be ... | 1998 | 9553087 |
| isolation of mutants of the arabidopsis thaliana alternative oxidase (ubiquinol:oxygen oxidoreductase) resistant to salicylhydroxamic acid. | the plant-type ubiquinol:oxygen oxidoreductase, commonly called the alternative oxidase, is a respiratory enzyme thought to contain non-heme iron at its active site. to explore the structure of the enzyme by identifying amino acids involved in inhibitor-binding, a library of random mutants of the arabidopsis thaliana alternative oxidase was constructed using error-prone polymerase chain reaction and expressed in the heme-deficient escherichia coli sasx41b. selection for resistance to salicylhydr ... | 1998 | 9554960 |
| characterization of delta 9 acyl-lipid desaturase homologues from arabidopsis thaliana. | two cdnas, ads1 and ads2, were isolated from arabidopsis. these cdnas encoded proteins homologous to delta 9 acyl-lipid desaturases of cyanobacteria and acyl-coa desaturases of yeast and mammals. the expression of ads1 and ads2 was organ-dependent. cold temperature up-regulated the ads2 expression, whereas it down-regulated the ads1 expression. | 1998 | 9559566 |
| a distinct cyclin-dependent kinase-activating kinase of arabidopsis thaliana. | the activation of cyclin-dependent kinases (cdks) requires phosphorylation of a threonine residue within the t-loop catalyzed by cdk-activating kinases (caks). thus far no functional cak homologue has been reported in plants. we screened an arabidopsis cdna expression library for complementation of a budding yeast cak mutant. a cdna, cak1at, was isolated that suppressed the cak mutation in budding yeast, and it also complemented a fission yeast cak mutant. cak1at encodes a protein related to ani ... | 1998 | 9560221 |
| association of the arabidopsis ctr1 raf-like kinase with the etr1 and ers ethylene receptors. | in arabidopsis thaliana, signal transduction of the hormone ethylene involves at least two receptors, etr1 and ers, both of which are members of the two-component histidine protein kinase family that is prevalent in prokaryotes. the pathway also contains a negative regulator of ethylene responses, ctr1, which closely resembles members of the raf protein kinase family. ctr1 is thought to act at or downstream of etr1 and ers based on double mutant analysis; however, the signaling mechanisms leadin ... | 1998 | 9560288 |
| isolation of a mutant of arabidopsis thaliana carrying two simultaneous mutations affecting tobacco mosaic virus multiplication within a single cell. | tobacco mosaic virus strain cg (tmv-cg) infects a. thaliana systemically. in order to identify host factors involved in the multiplication of tmv-cg, we isolated mutant of a. thaliana from an m2 population mutagenized by fast neutron irradiation, in which the accumulation of the coat protein in upper systemic leaves was reduced to low levels. the phenotype of the mutant, ys241, was controlled primarily by a single nuclear recessive mutation named tom2-1, which was distinct from tom1, a separate ... | 1998 | 9568044 |
| identification of non-heme diiron proteins that catalyze triple bond and epoxy group formation. | acetylenic bonds are present in more than 600 naturally occurring compounds. plant enzymes that catalyze the formation of the delta12 acetylenic bond in 9-octadecen-12-ynoic acid and the delta12 epoxy group in 12,13-epoxy-9-octadecenoic acid were characterized, and two genes, similar in sequence, were cloned. when these complementary dnas were expressed in arabidopsis thaliana, the content of acetylenic or epoxidated fatty acids in the seeds increased from 0 to 25 or 15 percent, respectively. bo ... | 1998 | 9572738 |
| cloning, expression in escherichia coli, and characterization of arabidopsis thaliana ump/cmp kinase. | a cdna encoding the arabidopsis thaliana uridine 5'-monophosphate (ump)/cytidine 5'-monophosphate (cmp) kinase was isolated by complementation of a saccharomyces cerevisiae ura6 mutant. the deduced amino acid sequence of the plant ump/cmp kinase has 50% identity with other eukaryotic ump/cmp kinase proteins. the cdna was subcloned into pgex-4t-3 and expressed as a glutathione s-transferase fusion protein in escherichia coli. following proteolytic digestion, the plant ump/cmp kinase was purified ... | 1998 | 9576794 |
| isolation of the ornithine-delta-aminotransferase cdna and effect of salt stress on its expression in arabidopsis thaliana. | to evaluate the relative importance of ornithine (orn) as a precursor in proline (pro) synthesis, we isolated and sequenced a cdna encoding the orn-delta-aminotransferase (delta-oat) from arabidopsis thaliana. the deduced amino acid sequence showed high homology with bacterial, yeast, mammalian, and plant sequences, and the n-terminal residues exhibited several common features with a mitochondrial transit peptide. our results show that under both salt stress and normal conditions, delta-oat acti ... | 1998 | 9576796 |
| nucleosome assembly on telomeric sequences. | the organization of telomeric chromatin differs from that of bulk chromatin in some peculiar features, such as the unusually short nucleosomal spacing found in vertebrates. telomeric dnas are straight, since they consist mostly of 6-8-bp repeated sequences, therefore out of phase with the b dna period. this feature should be of relevance in nucleosome formation, suggesting the usefulness of studying simple model systems of nucleosome assembly. we reconstituted nucleosomes in vitro, by using puri ... | 1998 | 9578556 |
| intron loss and gain during evolution of the catalase gene family in angiosperms. | angiosperms (flowering plants), including both monocots and dicots, contain small catalase gene families. in the dicot, arabidopsis thaliana, two catalase (cat) genes, cat1 and cat3, are tightly linked on chromosome 1 and a third, cat2, which is more similar to cat1 than to cat3, is unlinked on chromosome 4. comparison of positions and numbers of introns among 13 angiosperm catalase genomic sequences indicates that intron positions are conserved, and suggests that an ancestral catalase gene comm ... | 1998 | 9584109 |
| characterization of a dead box atpase/rna helicase protein of arabidopsis thaliana. | we have isolated cdnas encoding a novel member of the dead box rna helicase family from arabidopsis. the protein, named atdrh1, is composed of 619 amino acids and the central portion has high similarity with the helicase core region of a prototypic rna helicase, the human nuclear protein p68. the n- and c-terminal regions are considerably diverged from the animal and yeast p68 homologs at the amino acid sequence level, but like the p68 subfamily members, an rgg box-like domain is present near th ... | 1998 | 9592148 |
| site-specific integration of agrobacterium t-dna in arabidopsis thaliana mediated by cre recombinase. | in this study agrobacterium tumefaciens transferred dna (t-dna) was targeted to a chromosomally introduced lox site in arabidopsis thaliana by employing the cre recombinase system. to this end, arabidopsis target lines were constructed which harboured an active chimeric promoter-lox-cre gene stably integrated in the plant genome. a t-dna vector with a promoterless lox -neomycin phosphotransferase (nptii) fusion was targeted to this genomic lox site with an efficiency of 1.2-2.3% of the number of ... | 1998 | 9592161 |
| generation of broad-spectrum disease resistance by overexpression of an essential regulatory gene in systemic acquired resistance. | the recently cloned npr1 gene of arabidopsis thaliana is a key regulator of acquired resistance responses. upon induction, npr1 expression is elevated and the npr1 protein is activated, in turn inducing expression of a battery of downstream pathogenesis-related genes. in this study, we found that npr1 confers resistance to the pathogens pseudomonas syringae and peronospora parasitica in a dosage-dependent fashion. overexpression of npr1 leads to enhanced resistance with no obvious detrimental ef ... | 1998 | 9601001 |
| functional expression in yeast and characterization of a clofibrate-inducible plant cytochrome p-450 (cyp94a1) involved in cutin monomers synthesis. | the chemical tagging of a cytochrome p-450-dependent lauric acid omega-hydroxylase from clofibrate-treated vicia sativa seedlings with [1-14c]11-dodecynoic acid allowed the isolation of a full-length cdna designated cyp94a1. we describe here the functional expression of this novel p-450 in two saccharomyces cerevisiae strains overproducing their own nadph-cytochrome p-450 reductase or a reductase from arabidopsis thaliana. the results show a much higher efficiency of the yeast strain overproduci ... | 1998 | 9601090 |
| molecular cloning and expression of gdp-d-mannose-4,6-dehydratase, a key enzyme for fucose metabolism defective in lec13 cells. | subsets of mammalian cell surface oligosaccharides contain specific fucosylated moieties expressed in lineage- and/or temporal-specific patterns. the functional significance of these fucosylated structures is incompletely defined, although there is evidence that subsets of them, represented by the sialyl lex determinant, are important participants in leukocyte adhesion and trafficking processes. genetic deletion of these fucosylated structures in the mouse has been a powerful tool to address fun ... | 1998 | 9603974 |
| major chromosomal rearrangements induced by t-dna transformation in arabidopsis. | we show that major chromosomal rearrangements can occur upon t-dna transformation of arabidopsis thaliana. in the acl4 line, two t-dna insertion loci were found; one is a tandem t-dna insert in a head-to-head orientation, and the other is a truncated insert with only the left part of the t-region. the four flanking dna regions were isolated and located on the arabidopsis chromosomes; for both inserts, one side of the t-dna maps to chromosome 2, whereas the other side maps to chromosome 3. both c ... | 1998 | 9611180 |
| members of the arabidopsis actin gene family are widely dispersed in the genome. | plant genomes are subjected to a variety of dna turnover mechanisms that are thought to result in rapid expansion and presumable contraction of gene copy number. the evolutionary history of the 10 actin genes in arabidopsis thaliana is well characterized and can be traced to the origin of vascular plant genomes. knowledge about the genomic position of each actin gene may be the key to tracing landmark genomic duplication events that define plant families or genera and facilitate further mutant i ... | 1998 | 9611182 |
| molecular organization of the 20s proteasome gene family from arabidopsis thaliana. | the 20s proteasome is the proteolytic complex in eukaryotes responsible for degrading short-lived and abnormal intracellular proteins, especially those targeted by ubiquitin conjugation. the 700-kd complex exists as a hollow cylinder comprising four stacked rings with the catalytic sites located in the lumen. the two outer rings and the two inner rings are composed of seven different alpha and beta polypeptides, respectively, giving an alpha7/beta7/beta7/alpha7 symmetric organization. here we de ... | 1998 | 9611183 |
| characterization of the putative transposase mrna of tag1, which is ubiquitously expressed in arabidopsis and can be induced by agrobacterium-mediated transformation with dtag1 dna. | tag1 is an autonomous transposable element of arabidopsis thaliana. tag1 expression was examined in two ecotypes of arabidopsis (columbia and no-0) that were transformed with camv 35s-tag1-gus dna. these ecotypes contain no endogenous tag1 elements. a major 2.3-kb and several minor transcripts were detected in all major organs of the plants. the major transcript encoded a putative transposase of 84.2 kd with two nuclear localization signal sequences and a region conserved among transposases of t ... | 1998 | 9611184 |
| agrobacterium tumefaciens transformation and cotransformation frequencies of arabidopsis thaliana root explants and tobacco protoplasts. | in view of the recent finding that different t-dnas tend to ligate and integrate as repeats at single chromosomal positions, the frequency of transformation and cotransformation was determined during cocultivation of arabidopsis thaliana root explants and nicotiana tabacum protoplasts with two agrobacterium strains. the transformation frequency of unselected a. thaliana shoots was lower than 1% whereas that of cocultivated tobacco protoplasts was approximately 18%. the cotransformation frequenci ... | 1998 | 9612943 |
| differential induction of the arabidopsis thaliana thi2.1 gene by fusarium oxysporum f. sp. matthiolae. | the arabidopsis thaliana thi2.1 gene is inducible by necrotrophic fungi through a signal transduction pathway different from that for pathogenesis-related (pr) proteins. we have identified three ecotypes that are susceptible (col-2, ler, and ws) and two ecotypes that are resistant (mt-0 and uk-4) to spray inoculation with fusarium oxysporum f. sp. matthiolae. the thi2.1 transcript level after infection correlates with resistance, being 5 to 10 times higher in the resistant than in the susceptibl ... | 1998 | 9612950 |
| entry of xanthomonas campestris pv. campestris into hydathodes of arabidopsis thaliana leaves: a system for studying early infection events in bacterial pathogenesis. | xanthomonas campestris pv. campestris (xcc) is a vascular pathogen of cruciferous plants that normally gains entry to plants via hydathodes. in order to study the basis of the preference for this protal of entry we have developed an arabidopsis thaliana model with attached or detached leaves partially immersed in a bacterial suspension. entry of bacteria into leaves, assessed by resistance to surface sterilization, could be detected after 1 h. dissection of leaves and histochemical staining for ... | 1998 | 9612952 |
| analysis of plastid dna-like sequences within the nuclear genomes of higher plants. | a wide-ranging examination of plastid (pt)dna sequence homologies within higher plant nuclear genomes (promiscuous dna) was undertaken. digestion with methylation-sensitive restriction enzymes and southern analysis was used to distinguish plastid and nuclear dna in order to assess the extent of variability of promiscuous sequences within and between plant species. some species, such as gossypium hirsutum (cotton), nicotiana tabacum (tobacco), and chenopodium quinoa, showed homogenity of these se ... | 1998 | 9615455 |
| molecular cloning and characterization of aldehyde oxidases in arabidopsis thaliana. | using degenerate primers designed by deduced amino acid sequences of known aldehyde oxidases (ao) from maize and bovine, two independent cdna fragments were amplified by reverse transcription-polymerase chain reaction (pcr). the two corresponding full-length cdnas (atao-1 and atao-2; 4,484 and 4,228 bp long, respectively) were cloned by screening the arabidopsis cdna library followed by rapid amplification of cdna end-pcr. these cdnas are highly homologous at both the nucleotide and amino acid s ... | 1998 | 9615466 |
| functional analysis of the promoter region of a maize (zea mays l.) h3 histone gene in transgenic arabidopsis thaliana. | a 1023 bp fragment and truncated derivatives of the maize (zea mays l.) histone h3c4 gene promoter were fused to the beta-glucuronidase (gus) gene and introduced via agrobacterium tumefaciens into the genome of arabidopsis thaliana. gus activity was found in various meristems of transgenic plants as for other plant histone promoters, but unexplained activity also occurred at branching points of both stems and roots. deletion of the upstream 558 bp of the promoter reduced its activity to an almos ... | 1998 | 9617800 |
| agrobacterium vird2 protein interacts with plant host cyclophilins. | agrobacterium tumefaciens induces crown gall tumors on plants by transferring a nucleoprotein complex, the t-complex, from the bacterium to the plant cell. the t-complex consists of t-dna, a single-stranded dna segment of the tumor-inducing plasmid, vird2, an endonuclease covalently bound to the 5' end of the t-dna, and perhaps vire2, a single-stranded dna binding protein. the yeast two-hybrid system was used to screen for proteins interacting with vird2 and vire2 to identify components in arabi ... | 1998 | 9618535 |
| identification of a family of zinc transporter genes from arabidopsis that respond to zinc deficiency. | millions of people worldwide suffer from nutritional imbalances of essential metals like zinc. these same metals, along with pollutants like cadmium and lead, contaminate soils at many sites around the world. in addition to posing a threat to human health, these metals can poison plants, livestock, and wildlife. deciphering how metals are absorbed, transported, and incorporated as protein cofactors may help solve both of these problems. for example, edible plants could be engineered to serve as ... | 1998 | 9618566 |
| the biosynthetic pathway of vitamin c in higher plants. | vitamin c (l-ascorbic acid) has important antioxidant and metabolic functions in both plants and animals, but humans, and a few other animal species, have lost the capacity to synthesize it. plant-derived ascorbate is thus the major source of vitamin c in the human diet. although the biosynthetic pathway of l-ascorbic acid in animals is well understood, the plant pathway has remained unknown-one of the few primary plant metabolic pathways for which this is the case. l-ascorbate is abundant in pl ... | 1998 | 9620799 |
| a single amino acid change in turnip crinkle virus movement protein p8 affects rna binding and virulence on arabidopsis thaliana. | comparison of the symptoms caused by turnip crinkle virus strain m (tcv-m) and tcv-b infection of a resistant arabidopsis thaliana line termed di-17 demonstrates that tcv-b has a greater ability to spread in planta. this ability is due to a single amino acid change in the viral movement protein p8 and inversely correlates with p8 rna binding affinity. | 1998 | 9621099 |
| an arabidopsis vps45p homolog implicated in protein transport to the vacuole. | the sec1p family of proteins is required for vesicle-mediated protein trafficking between various organelles of the endomembrane system. this family includes vps45p, which is required for transport to the vacuole in yeast (saccharomyces cerevisiae). we have isolated a cdna encoding a vps45 homolog from arabidopsis thaliana (atvps45). the cdna is able to complement both the temperature-sensitive growth defect and the vacuolar-targeting defect of a yeast vps45 mutant, indicating that the two prote ... | 1998 | 9625693 |
| function and substrate specificity of the gibberellin 3beta-hydroxylase encoded by the arabidopsis ga4 gene. | cdna corresponding to the ga4 gene of arabidopsis thaliana l. (heynh. ) was expressed in escherichia coli, from which cell lysates converted [14c]gibberellin (ga)9 and [14c]ga20 to radiolabeled ga4 and ga1, respectively, thereby confirming that ga4 encodes a ga 3beta-hydroxylase. ga9 was the preferred substrate, with a michaelis value of 1 microm compared with 15 microm for ga20. hydroxylation of these gas was regiospecific, with no indication of 2beta-hydroxylation or 2,3-desaturation. the capa ... | 1998 | 9625708 |
| identification and characterization of a locus (rtm1) that restricts long-distance movement of tobacco etch virus in arabidopsis thaliana. | screens of arabidopsis thaliana for susceptibility to tobacco etch virus (tev) revealed that each of 10 ecotypes were able to support genome replication and cell-to-cell movement in inoculated leaves. however, only four ecotypes, including c24 and la-er, supported complete infections in which tev was able to replicate and move from cell to cell and long distances through the vasculature. the rates of cell-to-cell movement of a reporter-tagged tev strain (tev-gus) in inoculated leaves of c24 and ... | 1998 | 9628015 |
| cloning and functional expression of atcoq3, the arabidopsis homologue of the yeast coq3 gene, encoding a methyltransferase from plant mitochondria involved in ubiquinone biosynthesis. | a mutant of saccharomyces cerevisiae deleted for the coq3 gene was constructed. coq3 encodes a 3,4-dihydroxy-5-hexaprenylbenzoate (dhhb) methyltransferase that catalyses the fourth step in the biosynthesis of ubiquinone from p-hydroxybenzoic acid. a full length cdna encoding a homologue of dhhb-methyltransferase was cloned from an arabidopsis thaliana cdna library by functional complementation of a yeast coq3 deletion mutant. the arabidopsis thaliana cdna (atcoq3) was able to restore the respira ... | 1998 | 9628017 |
| six arabidopsis thaliana homologues of the human respiratory burst oxidase (gp91phox). | an nadph oxidase analogous to that in mammalian phagocytes has been hypothesized to produce reactive oxygen species (ros) in the plant defence response. a. thaliana contains at least six gp91phox homologues, designated atrboha-f (a. thaliana respiratory burst oxidase homologues), which map to different positions. transcripts of three of these genes can be detected in healthy plants by rna gel blot analyses. the atrboh gene products are closely related to gp91phox and the intron locations suggest ... | 1998 | 9628030 |
| a calcium sensor homolog required for plant salt tolerance. | excessive sodium (na+) in salinized soils inhibits plant growth and development. a mutation in the sos3 gene renders arabidopsis thaliana plants hypersensitive to na+-induced growth inhibition. sos3 encodes a protein that shares significant sequence similarity with the calcineurin b subunit from yeast and neuronal calcium sensors from animals. the results suggest that intracellular calcium signaling through a calcineurin-like pathway mediates the beneficial effect of calcium on plant salt tolera ... | 1998 | 9632394 |
| mutations in the human sterol delta7-reductase gene at 11q12-13 cause smith-lemli-opitz syndrome. | the smith-lemli-opitz syndrome (slos; also known as "rsh syndrome" [mim 270400]) is an autosomal recessive multiple malformation syndrome due to a defect in cholesterol biosynthesis. children with slos have elevated serum 7-dehydrocholesterol (7-dhc) levels and typically have low serum cholesterol levels. on the basis of this biochemical abnormality, it has been proposed that mutations in the human sterol delta7-reductase (7-dhc reductase; e.c.1.3.1.21) gene cause slos. however, one could also p ... | 1998 | 9634533 |
| gene-for-gene disease resistance without the hypersensitive response in arabidopsis dnd1 mutant. | the cell death response known as the hypersensitive response (hr) is a central feature of gene-for-gene plant disease resistance. a mutant line of arabidopsis thaliana was identified in which effective gene-for-gene resistance occurs despite the virtual absence of hr cell death. plants mutated at the dnd1 locus are defective in hr cell death but retain characteristic responses to avirulent pseudomonas syringae such as induction of pathogenesis-related gene expression and strong restriction of pa ... | 1998 | 9636234 |
| root colonization by agrobacterium tumefaciens is reduced in cel, attb, attd, and attr mutants. | root colonization by agrobacterium tumefaciens was measured by using tomato and arabidopsis thaliana roots dipped in a bacterial suspension and planted in soil. wild-type bacteria showed extensive growth on tomato roots; the number of bacteria increased from 10(3) bacteria/cm of root length at the time of inoculation to more than 10(7) bacteria/cm after 10 days. the numbers of cellulose-minus and nonattaching attb, attd, and attr mutant bacteria were less than 1/10,000th the number of wild-type ... | 1998 | 9647796 |
| genetic characterization of rrs1, a recessive locus in arabidopsis thaliana that confers resistance to the bacterial soilborne pathogen ralstonia solanacearum. | the soilborne, vascular pathogen ralstonia solanacearum, the causative agent of bacterial wilt, was shown to infect a range of arabidopsis thaliana accessions. the pathogen was capable of infecting the col-5 accession in an hrp-dependent manner, following root inoculation. elevated bacterial population levels were found in leaves of col-5, 4 to 5 days after root inoculation by the gmi1000 strain. bacteria were found predominantly in the xylem vessels and spread systematically throughout the plan ... | 1998 | 9650298 |
| role of the agrobacterium tumefaciens vird2 protein in t-dna transfer and integration. | vird2 is one of the key agrobacterium tumefaciens proteins involved in t-dna processing and transfer. in addition to its endonuclease domain, vird2 contains a bipartite c-terminal nuclear localization sequence (nls) and a conserved region called omega that is important for virulence. previous results from our laboratory indicated that the c-terminal, bipartite nls and the omega region are not essential for nuclear uptake of t-dna, and further suggested that the omega domain may be required for e ... | 1998 | 9650299 |
| identification of an arabidopsis thaliana mutation (vsm1) that restricts systemic movement of tobamoviruses. | following inoculation, many plant viruses spread locally from cell to cell until they reach the vascular system, through which they then move to other parts of the plant, resulting in systemic infection. to isolate host genes involved in systemic transport of plant viruses, ethyl methanesulfonate-mutagenized arabidopsis thaliana plants were screened for significant delays in the systemic movement of turnip vein clearing virus (tcvc). one such mutant, designated vsm1 (virus systemic movement), wa ... | 1998 | 9650300 |
| the defense-related rice gene pir7b encodes an alpha/beta hydrolase fold protein exhibiting esterase activity towards naphthol as-esters. | acquired resistance of rice to pyricularia oryzae, the causing agent of rice blast, can be induced by inoculation with the non-host pathogen pseudomonas syringae pv. syringae. we have previously cloned a cdna and a corresponding gene (pir7b) whose transcripts accumulate upon infiltration with the resistance-inducing bacteria. the putative encoded product pir7b exhibits significant sequence similarity to two recently cloned hydroxynitrile lyases from manihot esculenta (cassava) and hevea brasisli ... | 1998 | 9652390 |
| prt1 of arabidopsis thaliana encodes a component of the plant n-end rule pathway. | mutants in the prt1 gene of arabidopsis thaliana are impaired in the degradation of a normally short-lived intracellular protein that contains a destabilizing n-terminal residue. proteins bearing such residues are the substrates of an ubiquitin-dependent proteolytic system called the n-end rule pathway. the chromosomal position of prt1 was determined, and the prt1 gene was isolated by map-based cloning. the 45-kda prt1 protein contains two ring finger domains and one zz domain. no other proteins ... | 1998 | 9653113 |
| rice (oryza sativa) centromeric regions consist of complex dna. | rice bacterial artificial chromosome clones containing centromeric dna were isolated by using a dna sequence (psau3a9) that is present in the centromeres of gramineae species. seven distinct repetitive dna elements were isolated from a 75-kilobase rice bacterial artificial chromosome clone. all seven dna elements are present in every rice centromere as demonstrated by fluorescence in situ hybridization. six of the elements are middle repetitive, and their copy numbers range from approximately 50 ... | 1998 | 9653153 |
| glutaredoxin function for the carboxyl-terminal domain of the plant-type 5'-adenylylsulfate reductase. | 5'-adenylylsulfate (aps) reductase (ec 1.8.99.-) catalyzes the reduction of activated sulfate to sulfite in plants. the evidence presented here shows that a domain of the enzyme is a glutathione (gsh)-dependent reductase that functions similarly to the redox cofactor glutaredoxin. the apr1 cdna encoding aps reductase from arabidopsis thaliana is able to complement the cysteine auxotrophy of an escherichia coli cysh [3'-phosphoadenosine-5'-phosphosulfate (paps) reductase] mutant, only if the e. c ... | 1998 | 9653199 |
| a plant surface protein sharing structural properties with animal integrins. | using a polyclonal antibody (p23) generated against the human platelet integrin aiib beta3 and a fitc-conjugate secondary antibody, fluorescence is observed at the surface of protoplasts isolated from arabidopsis thaliana and rubus fruticosus. arabidopsis thaliana cells grown in suspension culture containing p23 and glycylarginylglycylaspartylserine (grgds), a synthetic peptide containing the rgd sequence found in many extracellular matrix adhesive proteins demonstrated aberrant cell wall/plasma ... | 1998 | 9654050 |
| an arabidopsis cdna encoding a bifunctional glutamine amidotransferase/cyclase suppresses the histidine auxotrophy of a saccharomyces cerevisiae his7 mutant. | a cdna encoding a glutamine amidotransferase and cyclase catalyzing the fifth and sixth steps of the histidine (his) biosynthetic pathway has been isolated from arabidopsis thaliana. the n- and c-terminal domains of the primary structure deduced from a full-length arabidopsis hishf (at-hf) cdna showed significant homology to the glutamine amidotransferase and cyclase of microorganisms, respectively. effective suppression of the his auxotrophy of a saccharomyces cerevisiae his7 mutant with the at ... | 1998 | 9654139 |
| evolutionary relationships among putative rna-dependent rna polymerases encoded by a mitochondrial virus-like rna in the dutch elm disease fungus, ophiostoma novo-ulmi, by other viruses and virus-like rnas and by the arabidopsis mitochondrial genome. | the nucleotide sequence (2617 nucleotides) of virus-like double-stranded (ds) rna 3a in a diseased isolate, log1/3-8d2 (ld), of the ascomycete fungus ophiostoma novo-ulmi has been determined. one strand of the dsrna contains an open reading frame (orf) with the potential to encode a protein of 718 amino acids, and the complementary strand contains two smaller orfs with the potential to encode proteins of 178 and 182 amino acids, respectively. the large orf contains 12 uga codons which code for t ... | 1998 | 9657003 |
| from mosquito to man: identification of a novel protein kinase, hshpk, which is highly expressed in human hepatoma tissues. | protein kinases play an important role in the signaling pathway of growth factors in most of the higher organisms. during the study of protein kinase profiles of mosquitoes using rt-pcr and degenerate primers for consensus catalytic domain motifs to amplify protein kinase genes, we have noticed that a novel mosquito kinase, aapk-38, shares a stretch of amino acids identical to the corresponding domain in tousled gene of arabidopsis thaliana that is required for leaf and flower development. a 2.1 ... | 1998 | 9662073 |
| transformation of arabidopsis thaliana c24 leaf discs by agrobacterium tumefaciens. | | 1998 | 9664430 |
| in planta agrobacterium-mediated transformation of adult arabidopsis thaliana plants by vacuum infiltration. | | 1998 | 9664431 |