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gene expression during induction of somatic embryogenesis in carrot cell suspensions.we report the identification, via their cdnas, of genes which are temporarily transcribed during the initiation of somatic embryogenesis in carrot (daucus carota l.) cells cultured in an auxin-free medium. their expression is roughly associated with the first morphogenetic, or globular, stage. a cdna library (λ gt 10) was established using poly(a)(+) -rich rnas from cells deprived of auxin for 8 d. by differential screening a number of clones corresponding to early-induced embryogenic genes were ...199124193528
calcium-pumping atpases in vesicles from carrot cells : stimulation by calmodulin or phosphatidylserine, and formation of a 120 kilodalton phosphoenzyme.ca(2+)-atpases keep cytoplasmic [ca(2+)] low by pumping ca(2+) into intracellular compartments or out of the cell. the transport properties of ca(2+)-pumping atpases from carrot (daucus carota cv danvers) tissue culture cells were studied. atp-dependent ca(2+) transport in vesicles that comigrated with an endoplasmic reticulum marker, was stimulated three- to fourfold by calmodulin. cyclopiazonic acid (a specific inhibitor of the sarcoplasmic/endoplasmic reticulum ca(2+)-atpase) partially inhibi ...199116668581
initiation and proliferation of carrot callus using a combination of antibiotics.calli were initiated from carrot (daucus carota l. subsp. sativus hoffm.) root expiants and grown on media supplemented with a combination of carbenicillin at 0.3 mg/ml and vancomycin at 0.1 mg/ml in the absence of plant hormones or hormone analogs. the growth rate was about half of that obtained with a combination of α-naphthaleneacetic acid and n(6)-benzyladenine at 1 mg/l each. carbenicillin in the combination with vancomycin could be replaced by penicillin g; other penicillins tested in this ...199124186530
rapid purification and thermostability of the cytoplasmic aspartate aminotransferase from carrot suspension cultures.several isoenzymic forms of aspartate aminotransferase (aat) have been identified in protein extracts from carrot (daucus carota) cell suspension cultures. the cellular location of the major form (form i) of aat in carrot suspension cultures was determined by heat inactivation, subcellular fractionation, and amino acid sequence analysis. in mammalian systems, there are two forms of aat, a heat-stable cytoplasmic form and a heat-labile form in the mitochondria. the thermostability of three isoenz ...199116668442
a simple procedure for the isolation of pure nuclei from carrot embryos in synchronized cultures.a simple method is presented for the isolation of nuclei from somatic embryos of carrot (daucus carota l.), which is applicable to small amounts of material in synchronized culture. the method employs buffers containing a high concentration of glycerol to stabilize the structure of the nuclei. purification was carried out by centrifugation using preformed percoll gradients. treatment with cell wall-degrading enzymes prior to homogenization improved the efficiency of isolation and permitted a rep ...199124221667
variable methylation and differential replication of genomic dna in cultured carrot root expiants during growth induction as influenced by hormonal treatments.the methylation and amplification pattern of genomic dna of carrot root expiants (daucus carota l.) undergoes transitory changes during the cultural cycle. a high degree of variation was observed as early as 36 h after the incubation of fresh expiants in the nutrient medium and, depending on the hormonal treatment significant modifications occurred during 14 days of culture. proliferative tissue conditioned by kinetin showed an extensive reduction in dna methylation. changes in the dna amplifica ...199124213171
immunohistochemical localization of a glycoprotein, gp80, in the outermost layer of the developing endosperm of immature seeds of carrot.a glycoprotein (gp80) from the immature fruits of carrot (daucus carota l.) plants was purified through the sequential application of salt extraction, (nh4)2so4 precipitation, chromatography on columns of concanavalin a-sepharose, hydroxylapatite, and boronate, and electroelution, with subsequent sodium dodecylsulfate-polyacrylamide gel electrophoresis (sds-page). its apparent relative molecular mass (mr) was estimated to be 80 k by both sds-page and gel filtration at high ionic strength. the mr ...199124186342
modulation of auxin-binding proteins in cell suspensions : i. differential responses of carrot embryo cultures.this paper shows that the level of 2,4-dichlorophenoxyacetic acid (2,4-d) in the medium determines the level of auxin-binding proteins in the membranes of carrot, daucus carota, cells grown in suspension. this induction takes slightly more than 2 hours to complete and can be elicited by natural as well as synthetic auxins. the auxin binding sites thus generated, which are pronase-sensitive, bind 2,4-d, indoleacetic acid, and naphthalene-acetic acid (naa) equally well. however both alpha- and bet ...199116668416
the impact of domestication on the genetic variability in the orange carrot, cultivated daucus carota ssp. sativus and the genetic homogeneity of various cultivars.isozyme analysis of wild and domesticated accessions indicated that domestication of the cultivated carrot daucus carota ssp. sativus resulted in an insignificant reduction of all genetic variability and genetic distance estimates. although they are less variable genetically, cultivated forms maintain a high proportion of observed heterozygosity. relative to the overall genetic variability of the species, samples from four common cultivars 'red cored chantenay', 'scarlet nantes', 'danvers half l ...199124213074
heterogeneity and cell type-specific localization of a cell wall glycoprotein from carrot suspension cells.ep1, an extracellular protein from carrot (daucus carota) cell suspensions, has been partially characterized by means of an antiserum and a cdna clone. in both embryo and suspension cultures different molecular mass ep1 proteins were detected, some of which (31, 32, 52, and 54 kilodaltons) were bound to the cell wall and released into the medium, whereas others (49, 60, and 62 kilodaltons) were more firmly bound to the cell wall and could be extracted with a salt solution. immunoprecipitation of ...199116668246
biochemical differences between carrot inbreds differing in plant regeneration potential.cultures derived from domestic carrot (daucus carota l.) inbreds were found to vary with respect to regeneration potential as measured by the production of somatic embryos in suspension cultures. a number of biochemical parameters previously reported to distinguish embryogenic from non-embryogenic cultures of other species were measured in these carrot cell lines. ethylene production was found to be inversely related to regeneration potential. the cell line producing the greatest number of somat ...199124221496
extracts of marine cyanobacteria stimulated somatic embryogenesis of daucus carota l.twenty five strains of marine cyanobacteria were screened for their ability to promote carrot somatic embryogenesis. hot water extracts prepared from 21 of these strains promoted plantlet formation. extracts from four strains increased plantlet numbers to an average of over 3.7-fold. dialysates and nondialysates of each of these extracts also increased plantlet formation. for extracts from filamentous cyanobacteria, nostoc sp. and anabaena sp., dialysate was more effective (4.2-fold increase) th ...199124213686
purification and immunohistochemical detection of an embryogenic cell protein in carrot.an embryogenic cell protein from carrot (daucus carota l.), designated ecp31 for embryogenic cell protein and with a relative mass of 31,000, was purified by sequential column chromatographies. its apparent relative mass was estimated to be 120,000 by gel filtration. immunoblotting and immunohistochemical studies showed that ecp31 was preferentially localized in the peripheral cells of clusters of embryogenic cells in the presence of 2,4-dichlorophenoxyacetic acid (2,4-d) and disappeared during ...199116668093
selective sensitivity to methylmercury of specific cell aggregates and validity of the "nurse" cell concept.meristematic cells of carrot (daucus carota--ca68-10) were grown in a heterogeneous suspension culture in the absence of (2,4-dichlorophenoxy)acetic acid in 71-v medium in the dark. freshly inoculated cell cultures were treated daily with methyl mercury for the first 4 days and harvested on day 7. the cultures were separated (by selective filtration) into groups of aggregates varying in size from 44 to 900 microns. methyl mercury severely decreased the cell mass of the dominant (300-microns) fra ...19912065632
ethanol-induced injuries to carrot cells : the role of acetaldehyde.carrot (daucus carota l.) cell cultures show high sensitivity to ethanol since both unorganized cell growth and somatic embryogenesis are strongly inhibited by ethanol at relatively low concentrations (10-20 millimolar). the role of acetaldehyde on ethanol-induced injuries to suspension cultured carrot cells was evaluated. when ethanol oxidation to acetaldehyde is prevented by adding an alcohol-dehydrogenase (ec 1.1.1.1) inhibitor (4-methylpyrazole) to the culture medium, no ethanol toxicity was ...199116668049
the role of glutamate dehydrogenase in plant nitrogen metabolism.in vivo nuclear magnetic resonance spectroscopy, in vitro gas chromatography-mass spectrometry, and automated (15)n/(13)c mass spectrometry have been used to demonstrate that glutamate dehydrogenase is active in the oxidation of glutamate, but not in the reductive amination of 2-oxogiutarate. in cell suspension cultures of carrot (daucus carota l. cv chantenay), primary assimilation of ammonium occurs via the glutamate synthase pathway. glutamate dehydrogenase is derepressed in carbonlimited cel ...199116668014
specific levels of dna methylation in various tissues, cell lines, and cell types of daucus carota.the level of dna methylation in daucus carota was found to be tissue specific, but no simple correlation between developmental stage or age of tissue and the level of dna methylation was found. among three different suspension culture lines from the same variety grown under identical conditions, large differences in the level of dna methylation were observed. the highest and lowest levels were found in two embryogenic cell lines originating from the same clone. suspension cells from one of the e ...199116667947
tunicamycin-inhibited carrot somatic embryogenesis can be restored by secreted cationic peroxidase isoenzymes.somatic embryogenesis of carrot (daucus carota l.) is inhibited by the glycosylation inhibitor tunicamycin. this inhibition is reversible by the addition of correctly glycosylated glycoproteins which have been secreted into the culture medium. to identify the proteins responsible for complementation, glycoproteins present in the medium of embryo cultures were purified and tested for their activity in the tunicamycin inhibition/ complementation assay. a 38-kda glycoprotein was purified that could ...199124194238
volatiles identified from five stages of embryo development separated from a heterogeneous suspension culture of daucus carota.five stages of embryo development were fractionated from a mature culture of daucus carota (gelbe rheinsche), using a series of metal sieves. the composition of the population of embryos in each fraction was determined quantitatively from microscopic investigations. volatiles from samples of tissue from six stages of development were trapped on activated charcoal cartridges. these volatiles, some of which may play a significant role in the interaction of the plant with the carrot root fly (psila ...199124221846
plant cell growth under different levels of oxygen and carbon dioxide.an experimental system, in which gases of known composition were passed through flasks, was used to systematically study the effects of oxygen and carbon dioxide on plant cell growth. as expected, oxygen limiting conditions resulted in suppressed growth of catharanthus roseus cultures. oxygen limitations did not alter the amount of cell mass produced per gram of sugar consumed which suggests that the production of fermentative metabolites was limited. varying levels of carbon dioxide were observ ...199124226158
metabolic changes in carrot cells in response to simultaneous treatment with ultraviolet light and a fungal elicitor.ultraviolet light induces anthocyanin biosynthesis in cell cultures of an afghan cultivar of daucus carota (daucus carota l. ssp. sativus). simultaneous treatment with a fungal elicitor from pythium aphanidermatum results in an inhibition of the catalytic activity of chalcone synthase (chs), which in turn correlates with an inhibition of anthocyanin biosynthesis. on immunoblots, one isoenzyme (40 kda) of chs disappears upon elicitor treatment. on an mrna level, only the mrna for the 40-kda-chs i ...199124194154
levels of p34(cdc2)-like protein in dividing, differentiating and dedifferentiating cells of carrot.p34(cdc2) is a key cell-cycle protein in fission yeast that is necessary for progress in the cell cycle from the g1 to the s phase and from g2 through mitosis. homologues of p34(cdc2) have been found in all eukaryotes that have been investigated. levels of p34(cdc2)-like protein were studied by quantitative western blotting in developing cotyledons of daucus carota l. (carrot) seedlings, in expiants from the same seedlings transferred to tissueculture media with and without 2,4-dichlorophenoxyac ...199124186410
conditions favorable for the somatic embryogenesis in carrot cell culture enhance expression of the roic promoter-gus fusion gene.we obtained carrot (daucus carota) cells possessing the 5'-noncoding sequence of the orf12 gene (roic) of tl-dna of the ri plasmid and a structural gene of bacterial beta-glucuronidase by agrobacterium-mediated transformation. when such cells were cultured in medium containing 2,4-dichlorophenoxyacetic acid, substantial reduction in beta-glucuronidase activity was observed. upon transferring the cells from a 2,4-d-containing medium to one devoid of 2,4-dichlorophenoxyacetic acid, enhanced expres ...199116667958
bifunctional protein in carrot contains both aspartokinase and homoserine dehydrogenase activities.we have purified homoserine dehydrogenase to homogeneity and subjected polypeptide fragments derived from digests of the protein to amino acid sequencing. the amino acid sequence of homoserine dehydrogenase from carrot (daucus carota) indicates that in carrot both aspartokinase and homoserine dehydrogenase activities reside on the same protein. additional evidence that aspartokinase and homoserine dehydrogenase reside on a bifunctional protein is provided by coelution of activities during purifi ...199116668550
induced plant responses to pathogen attack. analysis and heterologous expression of the key enzyme in the biosynthesis of phytoalexins in soybean (glycine max l. merr. cv. harosoy 63).in soybean (glycine max l.), pathogen attack induces the formation of glyceollin-type phytoalexins. the biosynthetic key enzyme is a reductase which synthesizes 4,2', 4'-trihydroxychalcone in co-action with chalcone synthase. screening of a soybean cdna library from elicitor-induced rna in lambda gt11 yielded two classes of reductase-specific clones. the deduced proteins match to 100% and 95%, respectively, with 229 amino acids sequenced in the purified plant protein. four clones of class a were ...19911840523
characterization of three agrobacterium tumefaciens avirulent mutants with chromosomal mutations that affect induction of vir genes.three agrobacterium tumefaciens mutants with chromosomal mutations that affect bacterial virulence were isolated by transposon mutagenesis. two of the mutants were avirulent on all hosts tested. the third mutant, ivr-211, was a host range mutant which was avirulent on bryophyllum diagremontiana, nicotiana tabacum, n. debneyi, n. glauca, and daucus carota but was virulent on zinnia elegans and lycopersicon esculentum (tomato). that the mutant phenotype was due to the transposon insertion was dete ...19911846853
proteolytic and partial sequencing studies of the bifunctional dihydrofolate reductase-thymidylate synthase from daucus carota.the bifunctional dihydrofolate reductase-thymidylate synthase (dhfr-ts) of daucus carota has been further characterized as regards molecular weight, amino acid composition, protease digestion and microsequencing of proteolytic peptides. data reported in this paper demonstrate that the carrot protein has a calculated mr of 124,000 thus indicating that, contrarily to what has previously been suggested, it occurs as a dimer of identical subunits. results of partial amino acid microsequencing show t ...19911863769
molecular cloning, induction and taxonomic distribution of caffeoyl-coa 3-o-methyltransferase, an enzyme involved in disease resistance.trans-caffeoyl-coa 3-o-methyltransferase is involved in the reinforcement of the plant cell wall under conditions that trigger the disease resistance response (pakusch, a.-e., kneusel, r.e., and matern, u. (1989) arch. biochem. biophys. 271, 488-494). partial amino acid sequences of the enzyme from cultured parsley cells that had been treated with a crude elicitor were identified (pakusch, a.-e., matern, u., and schiltz, e. (1991) plant physiol. 95, 137-143), and corresponding degenerated oligon ...19911894629
detection and prevalence of listeria monocytogenes in the agricultural ecosystem.the sensitivity of four different enrichment procedures to detect listeria monocytogenes in the presence of high levels of streptococcus faecalis was investigated. defined mixed cultures of strep. faecalis and l. monocytogenes gave better results with one-stage enrichment techniques. for manure samples, however, two-stage enrichment techniques gave the best performance. the so-called cold enrichment techniques were found to be unsatisfactory for samples from natural environments. the following m ...19911955415
[production of xanthan gum in immobilized cultures of xanthomonas campestris].the efficiency of xanthan production through surface processes was evaluated. the best porous material was selected first. thereafter, a comparative study was performed using submerged agitated process vs other without agitation but containing the selected porous material. the culture medium used was white potatoes infusion, buffered with k2hpo4 and supplemented with glucose in diverse concentrations. besides, to evaluate a different type of surface process, three vegetables were valued: ipomaea ...19921298018
isolation and genetic analysis of an agrobacterium tumefaciens avirulent mutant with a chromosomal mutation produced by transposon mutagenesis.a transposon 5 (tn5) insertion was introduced into the genome of a. tumefaciens (a-208 strain harboring a nopaline type ti-plasmid) using a conjugative pjb4ji plasmid containing tn5. five thousand transconjugants were assayed for virulence on carrot (daucus carota l.) disks; 54 isolates were avirulent or very attenuated. the cellular localization (plasmid or chromosome) of the tn5 insertion in those isolates were identified by southern hybridization analysis. an avirulent mutant (b-90 strain) wi ...19921369092
spatial and temporal expression patterns directed by the agrobacterium tumefaciens t-dna gene 5 promoter during somatic embryogenesis in carrot.we have analysed the patterns of expression of a gene encoding beta-glucuronidase (gus) fused to the promoter of the agrobacterium tumefaciens t-dna gene 5 during embryogenesis in carrot, daucus carota l. gene expression was monitored by a histochemical assay of beta-glucuronidase activity. the gene 5 promoter, although of bacterial origin, conferred expression upon the marker gene in all stages of embryo development. the patterns of expression however, differed between embryos in different stag ...19921558941
release of carrot plasma membrane-associated phosphatidylinositol kinase by phospholipase a2 and activation by a 70 kda protein.plasma membranes were isolated from carrot (daucus carota l.) cells grown in suspension culture and treated with phospholipase a2 from snake or bee venom for 10 min. as a result of this treatment, phosphatidylinositol kinase activity was recovered in the soluble fraction. there was no detectable diacylglycerol kinase or phosphatidylinositol monophosphate kinase activity released from the membranes after the phospholipase a2 treatment. treating the plasma membranes with phospholipase c or d did n ...19921311960
biosynthesis of p-hydroxybenzoic acid in elicitor-treated carrot cell cultures.carrot (daucus carota l.) cells respond to treatment with fungal elicitors by synthesizing wallbound p-hydroxybenzoic acid (p-hba). the biosynthetic pathway to p-hba is still hypothetical. tracer experiments with l-phenylalanine indicate the involvement of the general phenylpropanoid pathway. 3,4 (methylenedioxy) innamic acid, an inhibitor of hydrocycinnamate coa ligase, inhibits the accumulation of anthocyanins in carrot, while it does not interfere with p-hba synthesis. thus p-hba biosynthesis ...199224178394
identification and localisation of a nucleoporin-like protein component of the plant nuclear matrix.salt-detergent extraction of purified plant nuclei yields a fraction enriched in putative structural proteins known as the "nuclear matrix". compared with mammalian nuclear matrices, which contain three major proteins, plant nuclear matrices are complex, containing at least 100 polypeptides. in order to characterise more fully the plant nuclear matrix we have used antibodies raised against both yeast (saccharomyces cerevisiae) and mammalian (rat) nuclear pore proteins. we have shown that the nuc ...199224178083
effects of cropping sequences on population densities of meloidogyne hapla and carrot yield in organic soil.the influence of various cropping sequences on population densities of meloidogyne hapla and carrot yield was studied in organic soil under microplot-and field conditions. spinach, radish, barley, oat, and wheat were poor or nonhosts for m. hapla. population densities of m. hapla were maintained or increased on cabbage, celery, lettuce, leek, marigold, and potato. marketable percent-age and root weight of carrots were greater following spinach, oat, radish, and fallow-onion than those following ...199219283022
distribution of heterodera carotae and meloidogyne hapla in michigan carrot production.during 1986 and 1988, selected farms in all of the major carrot-growing counties of michigan were surveyed to determine the extent of infestation by heterodera carotae and meloidogyne hapla. both species were found in all eight counties surveyed, but not on all farms. heterodera carotae was recovered from 67.4% of the fields surveyed. meloidogyne hapla was detected in 24.8% of the samples and from 69.8% of the fields. in most cases, h. carotae and m. hapla occurred in the same field.199219283061
identification and expression of a cdna clone encoding aspartate aminotransferase in carrot.a full-length cdna clone encoding aspartate aminotransferase (aat) has been identified from a carrot root cdna library. degenerate oligo primers were synthesized from the known amino acid sequence of aat form i from carrot (daucus carota l. cv danvers). these primers were utilized in a polymerase chain reaction to amplify a portion of a carrot aat gene from first strand cdna synthesized from poly(a)(+) rna isolated from 5-d-old cell suspension cultures. the resulting 750-bp fragment was cloned, ...199216652971
the effect of exposure to microgravity on the development and structural organisation of plant protoplasts flown on biokosmos 9.preparatory experiments for the iml-1 (international microgravity laboratory) mission to be flown on the space shuttle in january, 1992, were performed on a 14 day flight on biokosmos 9 (kosmos 2044) in september 1989. the purpose of the experiment was to study the effect of weightlessness on protoplast regeneration. problems with late access to the space vehicle meant that the newly isolated protoplasts from hypocotyl cells of rapeseed (brassica napus l. cv niklas) and suspension cultures of ca ...199211541143
structural and functional organisation of regenerated plant protoplasts exposed to microgravity on biokosmos 9.preparatory experiments for the iml-1 mission using plant protoplasts, were flown on a 14-day flight on biokosmos 9 in september 1989. thirty-six hours before launch of the biosatellite, protoplasts were isolated from hypocotyl cells of rapeseed (brassica napus) and suspension cultures of carrot (daucus carota). ultrastructural and fluorescence analysis of cell aggregates from these protoplasts, cultured under microgravity conditions, have been performed. in the flight samples as well as in the ...199211536948
association of phosphatidylinositol kinase, phosphatidylinositol monophosphate kinase, and diacylglycerol kinase with the cytoskeleton and f-actin fractions of carrot (daucus carota l.) cells grown in suspension culture : response to cell wall-degrading enzymes.phosphatidylinositol kinase (pi), phosphatidylinositol monophosphate (pip) kinase, and diacylglycerol (dag) kinase activities were detected in the cytoskeletal fraction isolated from microsomes and plasma membranes of carrot (daucus carota l.) cells grown in suspension culture. the lipid kinase activities were associated with the actin filament fraction (f-actin fraction) isolated from the cytoskeleton. the pi and pip kinase activity in the f-actin fraction significantly increased after cells we ...199216653250
dynamics of nitrogenous assimilate partitioning between cytoplasmic and vacuolar fractions in carrot cell suspension cultures.bulk vacuole isolation, gas chromatography-mass spectrometry,, and high-performance liquid chromatography have been used to investigate the accumulation and partitioning of assimilated nitrogen supplied as (15)nh(4)cl between vacuolar and extravacuolar (cytoplasmic) fractions of protoplasts from suspension cultures of carrot (daucus carota l. cv chantenay). glutamine was the most abundant amino acid in the vacuole of protoplasts from late-exponential phase cells, whereas alanine, glutamate, and ...199216653201
bioreactor studies on the effect of dissolved oxygen concentrations on growth and differentiation of carrot (daucus carota l.) cell cultures.a bioreactor control system was used to investigate the effects of two dissolved oxygen concentrations (10% and 100%) on the growth and differentiation of daucus carota l. cell cultures. the strategy used allowed the dissolved oxygen concentration to be controlled without the need for changing either the agitator speed or the total gas flow rate. during the proliferation phase, reducing oxygen resulted in a lower growth rate and in a delay in sugar uptake kinetics. nonetheless, varying levels of ...199224213361
cdna cloning of an extracellular dermal glycoprotein of carrot and its expression in response to wounding.suspension-cultured cells of carrot (daucus carota l.) synthesize and secrete a glycoprotein that is normally found only in dermal tissues (epidermis, endodermis and periderm). this protein, previously called gp57, is now referred to as edgp (e xtracellular d ermal g lyco p rotein). we purified sufficient quantities of edgp to obtain amino-acid sequences on two internal tryptic peptides and screened a cdna library of young carrot roots with antiserum to edgp and with oligonucleotides correspondi ...199224178334
synthesis and accumulation of calmodulin in suspension cultures of carrot (daucus carota l.) : evidence for posttranslational control of calmodulin expression.the expression of calmodulin mrna and protein were measured during a growth cycle of carrot (daucus carota l.) cells grown in suspension culture. a full-length carrot calmodulin cdna clone isolated from a lambdagt10 library was used to measure steady-state calmodulin mrna levels. during the exponential phase of culture growth when mitotic activity and oxidative respiration rates were maximal, calmodulin mrna levels were 4- to 5-fold higher than they were during the later stages of culture growth ...199216653062
a gene expressed preferentially in the globular stage of somatic embryogenesis encodes elongation-factor 1 alpha in carrot.we have isolated cdna of genes that are preferentially expressed during somatic embryogenesis of carrot (daucus carota l.) by differential screening of globular embryos and cells that are dividing in an unorganized manner. as a result of northern-blot analysis, one of the genes identified in this way, which we refer to as cem1, was found to be expressed at high levels in somatic embryos at the globular and heart-shaped stages. in-situ hybridization using globular embryos revealed that the mrna t ...19921396695
differential accumulation of biotin enzymes during carrot somatic embryogenesis.the activities of four biotin enzymes, acetyl-coenzyme a (coa) carboxylase, 3-methylcrotonyl-coa carboxylase, pyruvate carboxylase, and propionyl-coa carboxylase, and the accumulation of six biotin-containing polypeptides were determined during development of somatic embryos of carrot (daucus carota). acetyl-coa carboxylase activity increased more than sevenfold, whereas the activities of 3-methylcrotonyl-coa carboxylase, pyruvate carboxylase, and propionyl-coa carboxylase were relatively unalte ...199216669096
a wound-inducible glycine-rich protein from daucus carota with homology to single-stranded nucleic acid-binding proteins.a cdna clone was isolated that encodes a wound-inducible glycine-rich protein. the homology of the carrot (daucus carota) protein with the a1 protein of the heterogeneous ribonucleoprotein complex suggests that the polypeptide plays a role in the biosynthesis and processing of heterogeneous nuclear rna and in the maturation of specific mrnas in response to wounding.199216669093
modulation of auxin-binding proteins in cell suspensions : ii. isolation and initial characterization of carrot cell variants impaired in somatic embryogenesis.cultured cell lines from carrot (daucus carota l.) with little or no embryogenic potential were examined for the auxin-binding capacity of their membranes. the lines belonged to different classes: (a) wild-type lines kept in culture for different periods (the longer the period, the lower being their embryogenic potential); (b) variants, isolated after mutagenesis, showing normal growth but a lack of embryogenic response; (c) auxin-resistant lines, isolated as colonies on solid media containing 4 ...199224203204
the effect of growth retardants on anthocyanin production in carrot cell suspension cultures.the effect of growth retardants on anthocyanin production was studied in wild carrot (daucus carota) cell suspension cultures. paclobutrazol [(2rs,3rs) - 1 - (4-chlorophenyl) - 4,4 -dimethyl-2-(1,2,4-triazol-1-yl) pentan-3-ol], uniconazole [(e)-1-(4-chlorophenyl-4,4 -) dimethyl-2-(1,2,4-triazol-1-yl)-1-penten-3-ol], tetcyclacis [5-(4-chloro-phenyl) -3,4,5,9,10-pentaaza-tetracyclo-5, 4, 10(2,6), o(8,11) - dodeca-3, 9-diene], ancymidol [α-cyclopropyl - 4 - methoxy-α(pyrimidine-5-yl)benzyl alcohol] ...199224203145
isolation and characterization of a cdna that encodes ecp31, an embryogenic-cell protein from carrot.a full-length cdna for ecp31, an embryogenic cell protein from carrot (daucus carota l.) with a m(r) of 31,000 (kiyosue t, satoh s, kamada h, harada h (1991) plant physiol 95: 1077-1083), was isolated from a cdna library prepared from embryogenic cells using pcr-amplified dna as a probe. the genomic southern blot analysis revealed that there are two or three genes for ecp31 in the carrot genome. the transcripts of ecp31 accumulated in the peripheral regions of clusters of embryogenic cells and d ...19921535801
anthocyanins from cell suspension cultures of daucus carota.six anthocyanins were isolated from cell suspension cultures of an afghan cultivar of daucus carota by pc or hplc. the structures of these compounds were elucidated by spectroscopic methods as cyanidin 3-o-lathyroside, cyanidin 3-o-(2''-o-beta-d-xylopyranosyl-6''-o-beta-d-glucopyranosyl-beta-d- galactopyranoside), and the latter acylated with 4-coumaric, ferulic, 4-hydroxybenzoic or sinapic acid. unusual 1h nmr chemical shifts and 1h noe data indicate an intramolecular copigmentation of the agly ...19921368363
transgenic plants containing the phosphinothricin-n-acetyltransferase gene metabolize the herbicide l-phosphinothricin (glufosinate) differently from untransformed plants.l-phosphinothricin (l-pt)-resistant plants were constructed by introducing a modified phosphinothricin-n-acetyl-transferase gene (pat) via agrobacterium-mediated gene transfer into tobacco (nicotiana tabacum l), and via direct gene transfer into carrot (daucus carota l). the metabolism of l-pt was studied in these transgenic, pt-resistant plants, as well as in the untransformed species. the degradation of l-pt, (14)c-labeled specifically at different c-atoms, was analysed by measuring the releas ...199224177979
intermediate filament antigens of 60 and 65 kda in the nuclear matrix of plants: their detection and localization.although the presence of a matrix in plant nuclei has been reported, major questions remain about its structural and biochemical features. we have used an intermediate filament antibody of broad specificity to explore whether daucus carota (carrot) nuclei and nuclear matrices contain intermediate filament/lamin antigens and, if so, where specifically they are localized. sds-page and western blotting revealed two bands, at 60 and 65 kda, that were highly immunoreactive with the intermediate filam ...19921544367
glyphosate selected amplification of the 5-enolpyruvylshikimate-3-phosphate synthase gene in cultured carrot cells.car and c1, two carrot (daucus carota l.) suspension cultures of different genotypes, were subjected to stepwise selection for tolerance to the herbicide glyphosate [(n-phosphonomethyl)glycine]. the specific activity of the target enzyme, 5-enolpyruvylshikimate-3-phosphate synthase (epsps), as well as the mrna level and copy number of the structural gene increased with each glyphosate selection step. therefore, the tolerance to glyphosate is due to stepwise amplification of the epsps genes. duri ...19921375313
promotion of plantlet formation from somatic embryos of carrot treated with a high molecular weight extract from a marine cyanobacterium.somatic embryos of daucus carota l. developed into plantlets at high frequency after addition of an extract from a marine cyanobacterium, synechococcus sp. nkbg 042902. high molecular weight, nondialyzing fraction, separated from the extract, possessed enhanced plantlet formation promoting activity. plantlet formation frequency was 60 % after addition of nondialysate (100 mg/l) compared to 28 % without addition. embryos treated with the nondialysate contained five times more chlorophyll than non ...199224213486
acylation of anthocyanins with hydroxycinnamic acids via 1-o-acylglucosides by protein preparations from cell cultures of daucus carota l.protein preparations from cell-suspension cultures of an afghan cultivar of daucus carota (carrot) catalyzed the formation of acylated anthocyanins from a cyanidin triglycoside isolated from the carrot cultures using (1-o-sinapoyl-, 1-o-feruloyl-) and 1-o-(p-coumaroyl)-β-glucose as acyl donors. the enzyme activities can be classified as 1-o-hydroxycinnamoyl-β-glucose: cyanidin 3-o-(2″-o-xylosyl-6″-o-glucosylgalactoside) 6‴-o-hydroxycinnamoyltransferases (ec 2.3.1.-).199224186789
immunological detection of acetaldehyde-protein adducts in ethanol-treated carrot cells.polyclonal antibodies able to recognize protein-acetaldehyde conjugates were produced and characterized. the antibodies react with sodium cyanoborohydride-reduced schiff's bases between acetaldehyde and a protein, independently of the nature of the macromolecule binding the acetaldehyde moiety. only conjugates between acetaldehyde or propionaldehyde and a protein are recognized; conjugates obtained with other aldehydes are not reactive. results concerning the formation of acetaldehyde adducts wi ...199216668764
regulation of glutamate dehydrogenase activity in relation to carbon limitation and protein catabolism in carrot cell suspension cultures.glutamate dehydrogenase (gdh) specific activity and function have been studied in cell suspension cultures of carrot (daucus carota l. cv chantenay) in response to carbon and nitrogen supply in the culture medium. the specific activity of gdh was derepressed in sucrose-starved cells concomitant with protein catabolism, ammonium excretion, and the accumulation of metabolically active amino acids. the addition of sucrose led to a rapid decrease in gdh specific activity, an uptake of ammonium from ...199216668745
purification and characterization of a soluble beta-fructofuranosidase from daucus carota.soluble beta-fructofuranosidase with an intracellular location and an isoelectric point of 3.8 (isoenzyme i) was purified and characterized from dry seeds and seedlings of carrot (daucus carota). the enzyme hydrolyzed sucrose with a km of 5 mm and a broad ph optimum around 5.0. the purified protein, which was n-glycosylated with high-mannose-containing and high-xylose-containing complex glycans, eluted as a monomeric polypeptide with a molecular mass of 68,000 from a gel-filtration column. on sd ...19921541302
unique patterns of mitochondrial genes, transcripts and proteins in different male-sterile cytoplasms of daucus carota.restriction fragment analysis of mitochondrial and chloroplast dnas from a brown anther and a petaloid cytoplasmic male-sterile (cms) line revealed unique patterns for each cms line distinct from those of normal fertile cytoplasms, but identical restriction fragments for all chloroplast dnas. the restauration of fertility through the introduction of nuclear restorer genes had no effect on the overall mitochondrial dna (mtdna) structure. the genomic environment and transcription patterns of sever ...199224202587
partial amino-acid sequence of ecp31, a carrot embryogenic-cell protein, and enhancement of its accumulation by abscisic acid in somatic embryos.ecp31, an embryogenic-cell protein from carrot (daucus carota l.), was purified by sequential column-chromatographic steps and digested by v8 protease on a nitrocellulose membrane. the resultant peptides were separated by reverse-phased column chromatography and sequenced. the sequences obtained were 70-80% homologous to those of a late-embryogenesis-abundant protein (d34) from cotton (baker et al, 1988, plant mol. biol. 11, 227-291). the level of ecp31 in somatic embryos of carrot was increased ...199224186729
xyloglucan endotransglycosylase activity in carrot cell suspensions during cell elongation and somatic embryogenesis.xyloglucan endotransglycosylase (xet) has been proposed to contribute to cell elongation through wall loosening. to explore this relationship further, we assayed this enzyme activity in suspensions of carrot (daucus carota l.) cells exhibiting various rates of cell elongation. in one cell line, elongation was induced by dilution into dichlorophenoxyacetic acid (2,4-d)-free medium. during this elongation, 93% of the xet activity was found in the culture medium; in nonelongating controls, by contr ...199312231995
novel o-d-galacturonoyl esters in the pectic polysaccharides of suspension-cultured plant cells.driselase digestion of uronate-6-14c-labeled primary walls of cultured spinach (spinacia oleracea l.) cells yielded about 18 novel uronate-containing compounds, most of which could be hydrolyzed by cold dilute alkali to yield oligo-[14c]galacturonides. one typical driselase digestion product (compound 17) yielded alpha-(1-->4)-d-[14c]galacturonotriose(gala3) upon very mild treatment with alkali (50% yield of gala3 in 7.2 min at ph 11 and 25 degrees c). one of the three galacturonate residues in ...19938022945
a cdna differentially expressed between embryogenic and nonembryogenic carrot (daucus carota l.) cells. 19938022926
flavonoids released by carrot (daucus carota) seedlings stimulate hyphal development of vesicular-arbuscular mycorrhizal fungi in the presence of optimal co2 enrichment.carbon dioxide has been previously identified as a critical volatile factor that stimulates hyphal growth ofgigaspora margarita, a vesiculararbuscular mycorrhizal fungus, and we determined the optimal concentration at 2.0%. the beneficial effect of co2 on fungal development is also visible in the presence of stimulatory (quercetin, myricetin) or inhibitory (naringenin) flavonoids. sterile root exudates from carrot seedlings stimulate the hyphal development ofg. margarita in the presence of optim ...199324248578
changes in phosphatidylinositol metabolism in response to hyperosmotic stress in daucus carota l. cells grown in suspension culture.carrot (daucus carota l.) cells plasmolyzed within 30 s after adding sorbitol to increase the osmotic strength of the medium from 0.2 to 0.4 or 0.6 osmolal. however, there was no significant change in the polyphosphorylated inositol phospholipids or inositol phosphates or in inositol phospholipid metabolism within 30 s of imposing the hyperosmotic stress. maximum changes in phosphatidylinositol 4-monophosphate (pip) metabolism were detected at 5 min, at which time the cells appeared to adjust to ...19938029337
a novel hydroxyproline-deficient arabinogalactan protein secreted by suspension-cultured cells of daucus carota (purification and partial characterization).arabinogalactan proteins (agps) are secreted or membrane-associated glycoproteins that have been operationally defined as binding to [beta]-glucosyl yariv artificial antigen, being rich in arabinose and galactose, and containing high levels of alanine, serine, and hydroxyproline. using an anti-agp monoclonal antibody (mac 207) bound to cyanogen bromide-activated sepharose 4b, we have purified by immunoaffinity chromatography an extracellular agp from the culture medium of suspension-cultured cel ...199312231918
purification and characterization of 3-methylcrotonyl-coa carboxylase from somatic embryos of daucus carota.3-methylcrotonyl-coa carboxylase, a biotin enzyme, was purified from embryos of daucus carota. polyethylene glycol precipitation and monomeric avidin affinity chromatography were used to purify all biotin enzymes from cell-free extracts of embryos. the resulting 3-methylcrotonyl-coa carboxylase preparation had a specific activity of 745 nmol/min.mg protein, representing a 3725-fold purification of the enzyme and a 135% recovery of activity. fractionation of the purified biotin-containing protein ...19938393642
a plasma membrane-type ca2+-atpase of 120 kilodaltons on the endoplasmic reticulum from carrot (daucus carota) cells (properties of the phosphorylated intermediate).cytosolic ca2+ levels are regulated in part by ca2+-pumping atpases that export ca2+ from the cytoplasm; however, the types and properties of ca2+ pumps in plants are not well understood. we have characterized the kinetic properties of a 120-kd phosphoenzyme (pe) intermediate formed during the reaction cycle of a ca2+-atpase from suspension-cultured carrot (daucus carota) cells. only one ca2+-dependent phosphoprotein was formed when carrot membrane vesicles were incubated with [[gamma]-32p]atp ( ...199312231855
oviposition stimulants for the black swallowtail butterfly: identification of electrophysiologically active compounds in carrot volatiles.headspace volatiles were collected from undamaged foliage of carrot,daucus carota, a host-plant species of the black swallowtail butterfly,papilio polyxenes. the volatiles were fractionated over silica on an open column, and the fractions were tested in behavioral assays withp. polyxenes females in laboratory experiments. the polar fractions, as well as the total mixture of volatiles, increased the landing frequency and the number of eggs laid on model plants with leaves bearing contact-oviposit ...199324249074
effect of intracellular glutathione level on the production of 6-methoxymellein in cultured carrot (daucus carota) cells.to produce phytoalexin, 6-methoxymellein (6-mm) was induced in suspension cultures of carrot (daucus carota) by buthionine sulfoximine (bso) and cucl2. addition of bso (a specific inhibitor of glutathione [gsh] synthesis) to the cultures lowered the cellular gsh levels. this depletion of gsh was bso-concentration dependent, and the extent of 6-mm accumulation was dependent on the gsh depletion. the accumulation of 6-mm induced by bso was suppressed by exogenous gsh. exogenous h2o2 stimulated the ...199312231796
characterization of a gene that is expressed early in somatic embryogenesis of daucus carota.the emb-1 mrna of carrot (daucus carota) was isolated as an embryo abundant cdna clone (t.h. ulrich, e.s. wurtele, b.j. nikolau [1990] nucleic acids res 18: 2826). northern analyses of rna isolated from embryos, cultured cells, and a variety of vegetative organs indicate that the emb-1 mrna specifically accumulates in embryos, beginning at the early stages of embryo development. in situ hybridization with both zygotic and somatic embryos show that the emb-1 mrna begins to accumulate at low level ...19938108498
population and biomass kinetics in fed-batch cultures of daucus carota l. somatic embryos.the population dynamics of developing somatic embryos of carrot (daucur carota l.) was investigated in batch and fed-batch cultures using modified murashige and skoog medium. these substrate limitations coincided not only with stoppage of biomass increase, but also with the increase in total concentration of embryos as well as the advancement of the embryo into a more mature stage. both glucose and ammonium were depleted from the culture. restoring either glucose, or ammonium and nitrate, as to ...199318609625
stimulation of calcium influx and calcium cascade by cyclic amp in cultured carrot cells.treatment of cultured carrot (daucus carota l.) cells with activators of adenylate cyclase, forskolin, and cholera toxin induced the biosynthesis of an antifungal isocoumarin, 6-methoxymellein, in the cells. addition of dibutyryl cyclic amp to carrot cell culture also stimulated the accumulation of the compound. the cyclic amp-evoked 6-methoxymellein production was significantly depressed in the presence of certain inhibitors of calcium cascade such as ca2+ channel blockers and inhibitors of cal ...19938385897
cdna cloning of ecp40, an embryogenic-cell protein in carrot, and its expression during somatic and zygotic embryogenesis.a cdna of 1.2 kb was isolated from a cdna library of embryogenic cells of carrot (daucus carota l.) by use of nucleotide sequences that encode two internal amino-acid sequences of ecp40 (an embryogenic-cell protein with a relative molecular mass of 40,000). a genomic southern blot using the cdna as probe suggested that there are at least two genes for ecp40 in the carrot genome. the cdna encoded an open reading frame of 306 amino acids, and the deduced amino-acid sequence was found to share two ...19938490126
density dependence of anaphes sordidatus (hymenoptera: mymaridae) parasitism on eggs of listronotus oregonensis (coleoptera: curculionidae).listronotus oregonensis (leconte) (coleoptera: curculionidae) oviposits in carrot leaves and the larvae feed in carrot roots. its eggs are parasitized by anaphes sordidatus (girault) (hymenoptera: mymaridae) throughout its oviposition period. this parasitoid is the major biotic mortality factor for l. oregonensis. parasitism by a. sordidatus was studied for three years in sequentially sown plots of carrots, daucus carota var. sativa. over the scason, significantly fewer l. oregonensis eggs were ...199328313777
rapid changes in amplification and methylation pattern of genomic dna in cultured carrot root explants (daucus carota l.).rapid genomic dna variation due to methylation and copy number alteration was observed in carrot root explants 6 h after inoculation and during a 36-h period of exponential callus growth. de novo methylation and amplification of restricted bspni fragments of low molecular weight occurred before cell cycle activation and should, therefore, be independent of progression through the s-phase of the cell cycle. growth regulators seemed to influence the amplification pattern indirectly by regulating c ...199324196052
solubilized proteins from carrot (daucus carota l.) membranes bind calcium channel blockers and form calcium-permeable ion channels.calcium channels have been suggested to play a major role in the initiation of a large number of signal transduction processes in higher plant cells. however, molecular components of higher plant ca2+ channels remain unidentified to date. calcium channel blockers of the phenylalkylamine family and bepridil specifically inhibit ca2+ influx into carrot (daucus carota l.) cells. by using a phenylalkylamine azido derivative, a 75-kda carrot membrane protein has been previously identified. here we ha ...199311607356
expression of dcprp1 is linked to carrot storage root formation and is induced by wounding and auxin treatment.a carrot (daucus carota, l.) genomic clone (dcprp1) was isolated on the basis of its homology to previously described cdnas encoding a wound-inducible, proline-rich cell wall protein. dna sequence analysis showed that dcprp1 contains a single open-reading frame encoding a 235-amino acid protein that is colinear with that predicted from the cdna sequence with the exception of four amino acids at the n terminus and a 60-nucleotide insertion present within the genomic clone. genomic southern hybrid ...19938278498
nitrogen and carbohydrate storage in biennials originating from habitats of different resource availability.four biennial species (arctium tomentosum, cirsium vulgare, dipsacus sylvester and daucus carota) which originate from habitats of different nutrient availability were investigated in a 2-year experiment in a twofactorial structured block design varying light (natural daylight versus shading) and fertilizer addition. the experiment was designed to study storage as reserve formation (competing with growth) or as accumulation (see chapin et al. 1990). we show that (i) the previous definitions of s ...199328313438
damage to italian crops caused by cyst-forming nematodes.investigations were undertaken in 1982-88 to estimate yield losses of carrot, sugarbeet, wheat, and potato caused by cyst-forming nematodes (heterodera and globodera species) in several provinces of italy. soil samples were collected at planting in 0.5-ha sampling areas distributed in each crop's major production area. yield loss estimates were based on nematode population estimates and on curves derived earlier relating nematode densities with crop yields in italy. estimated yield loss values w ...199319279850
complementary immunolocalization patterns of cell wall hydroxyproline-rich glycoproteins studied with the use of antibodies directed against different carbohydrate epitopes.antisera raised against the major hydroxyproline-rich glycoprotein (hrgp) in carrot (daucus carota l.) taproot, extensin-1, and a minor hrgp, extensin-2, were characterized by western blot analysis, enzyme-linked immunosorbent assay, and periodate oxidation and found to be directed against carbohydrate epitopes shared by both glycoproteins. the anti-extensin-1 antibodies (ge1) target periodate-sensitive epitopes and may recognize the terminal alpha-1,3-arabinoside of extensin-1. the anti-extensi ...19937506427
isolation and characterization of a cdna clone for plant nuclear antigen 21d7 associated with cell division.a cdna clone was isolated from a carrot (daucus carota l.) cdna expression library using monoclonal antibody 21d7, which recognizes a nuclear antigen associated with cell division in plant cells. to show that the isolated cdna encodes the 21d7 antigen, a polyclonal antiserum was raised against a recombinant fusion protein specified by the cdna. both the polyclonal antiserum and the monoclonal antibody 21d7 recognized the same plant protein on immunoblots, in immunoprecipitation experiments, and ...19938310059
molecular cloning and analysis of a cdna coding for the bifunctional dihydrofolate reductase-thymidylate synthase of daucus carota.molecular cloning of dihydrofolate reductase-thymidylate synthase (dhfr-ts) of daucus carota was achieved by immunoscreening of a cdna library obtaining a 2 kbp clone which contains an open reading frame of 1528 bp. comparison of the deduced amino acid sequence with those from other sources revealed the presence of motifs typical of dhfr and ts thus confirming the bifunctional nature of the carrot protein. as in other organisms, a higher degree of conservation was observed in the ts domain. anal ...19938329682
[granulated carrots (daucus carota) in dog nutrition].in feeding and balance trials with dogs (4) dried, ground carrots were tested in addition (30%) to a basic dry food (rice, corn gluten, fish meal and supplements). the palatability of both mixtures was good: fecal water losses were increased after feeding the carrots. apparent digestibilities of organic and inorganic matter, especially sodium and potassium (not phosphorus), decreased. digestibility of carrots was calculated to reach 70% with 1.2 mj of digestible energy per 100 g dry matter. redu ...19938430292
peptide splicing in the vacuolar atpase subunit a from candida tropicalis.subunit a of the vacuolar proton pump appears to be responsible for the atp hydrolysis which is coupled to the pumping of protons into a variety of intracellular acid compartments, including the fungal vacuole. we report here the cloning and sequence determination of the gene encoding subunit a from candida tropicalis. southern blot hybridization analysis indicates that there is a single gene which encodes this protein. the gene contains a single intron at the extreme 5'-end of the coding region ...19938463270
isolation and characterization of a new chromosomal virulence gene of agrobacterium tumefaciens.a mutant (strain b119) of agrobacterium tumefaciens with a chromosomal mutation was isolated by transposon (tn5) mutagenesis. the mutant exhibited growth rates on l agar and minimal medium (ab) plates similar to those of the parent strain (strain a208 harboring a nopaline-type ti plasmid). the mutant was avirulent on all host plants tested: daucus carota, cucumis sativus, and kalanchoe diagremontiana. the mutant was not impaired in attachment ability to carrot cells. the mutant had one insertion ...19938491736
identification and expression of a cdna from daucus carota encoding a bifunctional aspartokinase-homoserine dehydrogenase.aspartokinase (ec 2.7.2.4) and homoserine dehydrogenase (ec 1.1.1.3) catalyze steps in the pathway for the synthesis of lysine, threonine, and methionine from aspartate. homoserine dehydrogenase was purified from carrot (daucus carota l.) cell cultures and portions of it were subjected to amino acid sequencing. oligonucleotides deduced from the amino acid sequences were used as primers in a polymerase chain reaction to amplify a dna fragment using dna derived from carrot cell culture mrna as tem ...19938507831
elicitor-induced changes in ca2+ influx, k+ efflux, and 4-hydroxybenzoic acid synthesis in protoplasts of daucus carota l.suspension-cultured carrot cells (daucus carota) and their protoplasts respond to a fungal elicitor prepared from the culture medium of pythium aphanidermatum by accumulating 4-hydroxybenzoic acid (4-hba). protoplasts release the compound into the culture medium. using 45cacl2 as a tracer, we were able to demonstrate that the secretion of 4-hba is preceded by a rapid increase in the ca2+ influx and a concomitant k+ efflux. if the increased ca2+ influx was prevented by ethyleneglycol-bis([beta]-a ...199312231948
calcium levels affect the ability to immunolocalize calmodulin to cortical microtubules.calcium affects the stability of cortical microtubules (mts) in lysed protoplasts. this calmodulin (cam)-mediated interaction may provide a mechanism that serves to integrate cellular behavior with mt function. to test the hypothesis that cam associates with these mts, monoclonal antibodies were produced against cam, and one (designated mab1d10) was selected for its suitability as an immunocytochemical reagent. it is shown that cam associates with the cortical mts of cultured carrot (daucus caro ...199312231960
the metabolites of the herbicide l-phosphinothricin (glufosinate) (identification, stability, and mobility in transgenic, herbicide-resistant, and untransformed plants).the metabolism of the herbicide l-phosphinothricin (l-pt) was analyzed in tobacco (nicotiana tabacum), alfalfa (medicago sativa), and carrot (daucus carota). in transgenic, pt-resistant plants expressing the pt-n-acetyltransferase gene (pat), l-pt was acetylated, resulting in two forms of n-acetyl-pt (ac-pt). in transgenic plants expressing only low pat-encoded acetylating activity as well as in genetically unmodified plants, three metabolic compounds 4-methylphosphinico-2-oxo-butanoic acid, 3-m ...199412232195
molecular genetics of the maize (zea mays l.) aspartate kinase-homoserine dehydrogenase gene family.aspartate kinase (ak) and homoserine dehydrogenase (hsdh) are enzymes in the aspartate-derived amino acid biosynthetic pathway. recent biochemical evidence indicates that an ak-hsdh bifunctional enzyme exists in maize (zea mays l.). in this report, we characterize three genes that encode subunits of ak-hsdh. two cdnas, pakhsdh1 and pakhsdh2, containing the full-coding sequence, and one partial cdna, pakhsdh3, encode amino acid sequences similar to the reported monofunctional ak and hsdh enzymes ...19947846152
the highly edited orf206 in oenothera mitochondria may encode a component of a heme transporter involved in cytochrome c biogenesis.a highly transcribed region in oenothera mitochondria codes for a reading frame (orf206) which shows high homology to the marchantia encoded mitochondrial open reading frame orf277 and is also conserved in the mitochondrial genomes of arabidopsis thaliana and daucus carota. transcripts of orf206 are modified by cytidine to uridine changes in 46 positions by rna editing, affecting 30% of all cytidines and 15% of the total encoded amino acids. this orf is cotranscribed with an upstream reading fra ...19948003696
cdna cloning of carrot (daucus carota) soluble acid beta-fructofuranosidases and comparison with the cell wall isoenzyme.carrot (daucus carota), like most other plants, contains various isoenzymes of acid beta-fructofuranosidase (beta f) (invertase), which either accumulate as soluble polypeptides in the vacuole (isoenzymes i and ii) or are ionically bound to the cell wall (extracellular beta f). using antibodies against isoenzyme i of carrot soluble beta f, we isolated several cdna clones encoding polypeptides with sequences characteristic of beta fs, from bacteria, yeast, and plants. the cdna-derived polypeptide ...19948016265
[the in vitro action of plants on vibrio cholerae].natural products of several plants, according to the geographic location, are used by peruvian people in the popular treatment of diarrhea, with good success. when cholerae cases appeared in peru, we were interested to know the "in vitro" effect against vibrio cholerae 01, of these useful plants to treat diarrhea. the following plants were tested: cichorium intybus, althaea officinalis, psorela glandulosa, geranium maculatum, punica granatum, malus sativa, cydonia oblonga, chenopodium ambrosoide ...19948018898
a trna gene mapping within the chloroplast rdna cluster is differentially expressed during the development of daucus carota.in vivo analysis of expression of the chloroplast rdna cluster during somatic embryogenesis of daucus carota (d.carota) was performed by northern-blot analysis with different dna probes, spanning both the 16s rrna gene, the 16s-23s rrna spacer, which contains the two mosaic trna genes trna(ile) and trna(ala), and the region upstream of the 16s rrna gene, where a trna(val) maps. we show that expression both of the spacer trnas trna(ile) and trna(ala) is not significantly regulated during developm ...19948202376
analysis of the rolc promoter region involved in somatic embryogenesis-related activation in carrot cell cultures.in cell cultures of carrot (daucus carota l.), somatic embryogenesis can be induced by transferring cells from a medium containing 2,4-dichlorophenoxyacetic acid (2,4-d) to one devoid of 2,4-d. previous analysis of transgenic carrot cells containing the 5' non-coding sequence of the ri plasmid rolc and a structural gene for bacterial beta-glucuronidase (uida) has shown that the chimeric gene is actively expressed after induction of somatic embryogenesis. in this study, we demonstrate that activa ...19948016259
fourier-transform raman and fourier-transform infrared spectroscopy (an investigation of five higher plant cell walls and their components).infrared and raman spectra of sequentially extracted primary cell walls and their pectic polymers were obtained from five angiosperm plants. fourier-transform raman spectrometry was shown to be a powerful tool for the investigation of primary cell-wall architecture at a molecular level, providing complementary information to that obtained by fourier-transform infrared microspectroscopy. the use of an extraction procedure using imidazole instead of cyclohexane trans-1,2-n,n,n[prime],n[prime]-diam ...199412232436
mechanisms of the proliferation and differentiation of plant cells in cell culture systems.plant cell functions have been investigated in various cell culture systems. in this review, we summarize results obtained from investigations of gene expression during the cell cycle in synchronized cultures of catharanthus roseus during somatic embryogenesis in suspension cultures of daucus carota, during organogenesis in tissue cultures of arabidopsis thaliana and during the transdifferentiation of isolated mesophyll cells to tracheary elements in single-cell cultures of zinnia elegans.19947981037
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