| a chromo box gene from carrot (daucus carota l.): its cdna structure and expression during somatic and zygotic embryogenesis. | a cdna clone, designated dcdb1, was isolated from a cdna library prepared from embryogenic cell clusters of carrot (daucus carota l.) and characterized. the cdna (1416 bp) encoded for a protein of 392 amino acid residues that contained a conserved chromo domain. the chromo domain is a 37 aa region found in both the polycomo gene product, which is a repressor of homeotic genes, and a heterochromatin protein 1 of drosophila. this domain is postulated to function in the binding of proteins to chrom ... | 1998 | 9602049 |
| intracellular ph in arbuscular mycorrhizal fungi. a symbiotic physiological marker | a method was developed to perform real-time analysis of cytosolic ph of arbuscular mycorrhizal fungi in culture using dye and ratiometric measurements (490/450 nm excitations). the study was mainly performed using photometric analysis, although some data were confirmed using image analysis. the use of nigericin allowed an in vivo calibration. experimental parameters such as loading time and concentration of the dye were determined so that ph measurements could be made for a steady-state period o ... | 1998 | 9536044 |
| an apparent case of nonsymmetrical and sustained strand-specific hemimethylation in the dc8 gene of carrot. | the dc8 gene of carrot (daucus carota l.) shows differential expression during embryo development. changes in methylation patterns of a segment of about 500 bp (from base +120 to base -446) of dc8 allele 6 were investigated by treating genomic dna, extracted from embryogenic callus at different stages of development, with sodium bisulfite to modify nonmethylated cytosines. following asymmetric (strand-specific) amplification, base sequences for samples from each developmental stage were determin ... | 1998 | 9549056 |
| molecular systematics of apiaceae subfamily apioideae: phylogenetic analyses of nuclear ribosomal dna internal transcribed spacer and plastid rpo c1 intron sequences. | evolutionary relationships among representatives of apiaceae (umbelliferae) subfamily apioideae have been inferred from phylogenetic analyses of nuclear ribosomal dna internal transcribed spacer (its 1 and its 2) and plastid rpoc1 intron sequences. high levels of nucleotide sequence variation preclude the use of the its region for examining relationships across subfamilial boundaries in apiaceae, whereas the rpoc1 intron is more suitably conserved for family-wide phylogenetic study but is too co ... | 1998 | 21684940 |
| characterization of storage proteins in daucus carota l.: two novel proteins display zygotic embryo specificity. | although maturation-related proteins are well known in the endosperm of albuminous seeds, an important question is whether the zygotic embryo possesses its own maturation proteins. we report on the isolation and partial characterization of storage proteins of carrot (daucus carota l. var nandor) dry achenes and isolated zygotic embryos, using one- and two-dimensional electrophoresis techniques, hplc and amino acid sequencing. the presence of a series of abundant polypeptides showing charge heter ... | 1998 | 9517000 |
| malondialdehyde and 4-hydroxy-2-nonenal in plant tissue cultures: lc-ms determination of 2,4-dinitrophenylhydrazone derivatives. | the cytologically active secondary lipid peroxidation products, malondialdehyde (mda) and 4-hydroxy-2-nonenal (hne) have been detected as their 2,4-dinitrophenylhydrazone (dnp) derivatives in plant tissue cultures using lc-ms. this paper reports, for the first time, the use of lc-ms methodology to definitively identify 4-hydroxy-2-nonenal in plants. limits of detection for the two derivatives are approximately 5 pmol (1.2 x 10(-9) g; 1 microm) and 0.1 pmol (3 x 10(-11) g; 20 nm) respectively. ma ... | 1997 | 9350430 |
| action spectrum for induction of promoter activity of phenylalanine ammonia-lyase gene by uv in carrot suspension cells. | the full-length promoter (-2335) of the carrot (daucus carota) phenylalanine ammonia-lyase gene (gdcpal1) fused to the luciferase reporter gene was transiently transformed to carrot protoplasts by electroporation, and the promoter activity induced by monochromatic uv light of various wavelengths was examined. the action spectrum constructed from the fluence-response curves showed a single peak at around 280 nm, suggesting that the activation of the gdcpal1 promoter is categorizable as one of the ... | 1997 | 9337617 |
| peripheral framework of carrot cell nucleus contains a novel protein predicted to exhibit a long alpha-helical domain. | a monoclonal antibody, cml-1, raised against carrot (daucus carota l.) nuclear-matrix proteins selectively labeled the nuclear periphery of carrot protoplasts when visualized by confocal and electron microscopy. to identify the constituent proteins of higher plant cells structurally homologous to the vertebrate nuclear lamina, we cloned overlapping cdnas partially encoding a cml-1-recognized protein and determined the entire sequence including the open reading frame. when the deduced amino acid ... | 1997 | 9141634 |
| distinction between endoplasmic reticulum-type and plasma membrane-type ca2+ pumps (partial purification of a 120-kilodalton ca2+-atpase from endomembranes). | two biochemical types of ca2+-pumping atpases were distinguished in membranes that were isolated from carrot (daucus carota) suspension-cultured cells. one type hydrolyzed gtp nearly as well as atp, was stimulated by calmodulin, and was resistant to cyclopiazonic acid. this plasma membrane (pm)-type pump was associated with pms and endomembranes, including vacuolar membranes and the endoplasmic reticulum (er). another pump ("er-type") that was associated mainly with the er hydrolyzed atp prefere ... | 1997 | 12223624 |
| polyamines and pectins (i. ion exchange and selectivity). | the ion-binding and -exchange properties of putrescine, spermidine, and spermine on purified walls of carrot (daucus carota l.) cell suspensions were investigated by producing ion-exchange isotherms and comparing them with the behavior of na+, mg2+, and ca2+. the cation exchange capacity of the carrot cell walls was 0.8 equivalent kg-1 dry matter, and the ionic selectivity sequence of the walls for polyamines followed the sequence spermine4+ > spermidine3+ [almost equal to] ca2+ > putrescine2+. ... | 1997 | 12223613 |
| rhamnogalacturonan ii, a dominant polysaccharide in juices produced by enzymic liquefaction of fruits and vegetables. | rhamnogalacturonan ii (rg-ii), a small complex pectic polysaccharide, is released from apple (malus domestica), carrot (daucus carota), and tomato (solanum lycopersicum) by treatment with two commercial liquefying enzyme preparations. rg-ii was isolated by size-exclusion chromatography from apple, tomato, and carrot juices obtained by enzymic liquefaction. all the rg-iis contained the diagnostic sugars, apiose, 2-o-methyl-l-fucose, 2-o-methyl-d-xylose, aceric acid, kdo and dha. glycosyl-linkage ... | 1997 | 9060185 |
| quantification of contact oviposition stimulants for black swallowtail butterfly,papilio polyxenes, on the leaf surfaces of wild carrot,daucus carota. | ovipositing black swallowtail butterflies,papilio polyxenes, make their final host-selection decisions on the basis of compounds present on the leaf surface. little information is available, however, on the chemistry of leaf surfaces. the purpose of this study was to develop a technique to extract and quantify the concentrations of compounds from the leaf surfaces ofdaucus carota, one of the main host species forp. polyxenes, with particular reference to compounds already identified as contact o ... | 1996 | 24227308 |
| purification and characterization of neutral and alkaline invertase from carrot. | neutral and alkaline invertase were identified in cells of a suspension culture of carrot (daucus carota l.) and purified to electrophoretic homogeneity. neutral invertase is an octamer with a molecular mass of 456 kd and subunits of 57 kd, whereas alkaline invertase is a tetramer with a molecular mass of 504 kd and subunits of 126 kd. both enzymes had sharp ph profiles, with maximal activities at ph 6.8 for neutral invertase and ph 8.0 for alkaline invertase, and both hydrolyzed sucrose with ty ... | 1996 | 8972597 |
| isozyme patterns in zygotic and somatic embryogenesis of carrot. | isozyme patterns of carrot (daucus carota l.) zygotic embryos between the torpedo stage up to 5-day-old seedlings have been compared with those of the similar stages from the embryogenic cell suspension culture to the late somatic plantlet. somatic embryos blocked at the torpedo stage by β-cyclodextrine have also been analyzed. all these stages have been analyzed with respect to seven different enzyme systems: arylesterase, glucosephosphate isomerase, phosphogluconate dehydrogenase, alcohol dehy ... | 1996 | 24178665 |
| evidence for opposing effects of calmodulin on cortical microtubules. | microtubule integrity within the cortical array was visualized in detergent-lysed carrot (daucus carota l.) protoplasts that were exposed to various exogenous levels of ca2+ and calmodulin (cam). cam appears to help stabilize cortical microtubules against the destabilizing action of ca2+/cam complexes at low ca2+ concentrations, but not at higher ca2+ concentrations. the hypothesis that cam interacts with microtubules at two different sites, determined by the concentration of ca2+, is supported ... | 1996 | 12226434 |
| a new protoplast culture system in daucus carota l. and its applications for mutant selection and transformation. | petiole protoplasts from in vitro-grown carrot plants are a very good alternative to traditionally obtained protoplasts from suspension cultures. high plating and regeneration efficiencies were obtained in most of the breeding lines that were tested. the embedding of the protoplasts in alginate was crucial for initiating cell division and further development. several streptomycin resistant and chlorophyll-deficient plant lines were selected for using the petiole protoplast system. maternally inh ... | 1996 | 24162412 |
| the effects of exogenous auxins on endogenous indole-3-acetic acid metabolism (the implications for carrot somatic embryogenesis). | the effect of auxin application on auxin metabolism was investigated in excised hypocotyl cultures of carrot (daucus carota). concentrations of both free and conjugated indole-3-acetic acid (iaa), [2h4]iaa, 2,4-dichlorophenoxyacetic acid, and naphthaleneacetic acid (naa) were measured by mass spectroscopy using stable-isotope-labeled internal standards. [13c1]naa was synthesized for this purpose, thus extending the range of auxins that can be assayed by stable-isotope techniques. 2,4-dichlorophe ... | 1996 | 12226408 |
| purification and characterization of a wound-inducible cell wall cationic peroxidase from carrot roots. | we have isolated a novel cell wall, cationic peroxidase (pi > 9.3) from roots of the carrot plant, daucus carota. the purified isozyme, referred to as cp > 9.3, has a molecular mass of 45 kilodaltons and an reinheitzahl value of 2.3. amino-acid composition analysis and n-terminal sequencing have been performed with cp > 9.3. the n-terminal sequence shows no homology to any sequence in the protein and nucleic acid data banks. cp > 9.3 activity is induced by wounding in carrot leaves and petioles; ... | 1996 | 8806623 |
| molecular characterization and functional analysis of sucrose-cleaving enzymes in carrot (daucus carota l.). | the amount of carbon transported into storage organs of crop plants to a large degree determines crop yield. the role of sucrose-cleaving enzymes in this process is not clear and it is the main goal of our work to tackle this question. sucrose cleavage is catalysed either by invertase or sucrose synthase both of which exist in several isoforms with different subcellular locations. carrot (daucus carota l.) contains three major isoenzymes of acid invertase, which either accumulate as soluble poly ... | 1996 | 21245247 |
| characterization of membrane properties in desiccation-tolerant and -intolerant carrot somatic embryos. | in previous studies, we have shown that carrot (daucus carota l.) somatic embryos acquire complete desiccation tolerance when they are treated with abscisic acid during culture and subsequently dried slowly. with this manipulable system at hand, we have assessed damage associated with desiccation intolerance. fast drying caused loss of viability, and all k+ and carbohydrates leached from the somatic embryos within 5 min of imbibition. the phospholipid content decreased by about 20%, and the free ... | 1996 | 12226295 |
| visualization of plant cell walls by atomic force microscopy. | atomic force microscopy has been used to visualize the ultrastructure of hydrated plant cell wall material from prepared apple (malus pumila mill; cox orange pippin), water chestnut (eleocharis dulcis l.), potato (solanum tuberosum l.; bintje), and carrot (daucus carota l.; amsterdamse bak) parenchyma. samples of cell wall material in aqueous suspension were deposited onto freshly cleaved mica. excess water was blotted away and the moist samples were imaged in air at ambient temperature and humi ... | 1996 | 8785273 |
| structural and functional characterization of the intergenic spacer region of the rdna in daucus carota. | the intergenic spacer (igs) region of rdna in daucus carota contains at least eight kinds of repeated sequence. one sequence may act as a genuine initiation site for a stable transcript and another may act as a spacer promoter that may be an entry site for proteins required for transcription. | 1996 | 8665099 |
| extracellular calmodulin-binding proteins in plants: purification of a 21-kda calmodulin-binding protein. | a 21-kda calmodulin (cam)-binding protein and a 19-kda calmodulin-binding protein were detected in 0.1 m cacl2 extracts of angelica dahurica l. suspension-cultured cells and carrot (daucus carota l.) suspension-cultured cells, respectively, using a biotinylated cauliflower cam gel-overlay technique in the presence of 1 mm ca(2+). no bands, or very weak bands, were shown on sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels overlayed with biotinylated cauliflower cam when 1 mm ca(2+) ... | 1996 | 28321660 |
| variations in the structure of neutral sugar chains in the pectic polysaccharides of morphologically different carrot calli and correlations with the size of cell clusters. | carrot (daucus carota l.) embryogenic callus (ec) loses its embryogenic competence and becomes non-embryogenic callus (nc) during long-term culture. with the loss of embryogenic competence, the cell clusters become smaller and the extent of intercellular attachments is reduced. pectic fractions prepared from ec and nc were separated into two subfractions by gel filtration. a difference in sugar composition between ec and nc was found only in the high-molecular-mass (ca. 1300 kda) subfraction, an ... | 1996 | 8727449 |
| purification and characterization of glycosyltransferases involved in anthocyanin biosynthesis in cell-suspension cultures of daucus carota l. | the major anthocyanins accumulated by an afghan cultivar of daucus carota l. are cyanidin 3-(xylosylglucosylgalactosides) acylated with sinapic or ferulic acid. the formation of the branched triglycoside present as a common structural element requires an ordered sequence of glycosylation events. two of these enzymic glycosylation reactions have been detected in protein preparations from carrot cell-suspension cultures. the first step is a galactosyl transfer catalyzed by udp-galactose: cyanidin ... | 1996 | 8717136 |
| physiological aspects of genome variability in tissue culture. ii. growth phase-dependent quantitative variability of repetitive bstni fragments of primary cultures of daucus carota l. | systematic investigations on the occurrence of differential dna replication in carrot cultures, expressed at the total genome level, were performed. the genome of daucus carota l. could be characterized by a pattern of repetitive bstni fragments that was independent of tissue specificity or cultivar differences. characterization of the genomic dna of the secondary phloem of carrot roots, in comparison to the dna of the induced primary cultures at different growth phases, revealed dramatic differ ... | 1995 | 24169922 |
| physiological aspects of genome variability in tissue culture. i. growth phase-dependent differential dna methylation of the carrot genome (daucus carota l.) during primary culture. | investigations were performed on growth phase-dependent ecorii site-specific dna methylation of the carrot genome during primary culture to elucidate physiological aspects of genome dna variability in tissue culture. while dna methylation of the root cambium and the secondary phloem and petioles of carrot leaves were strikingly different, the methylation level of the secondary phloem seemed to be independent of cultivar origin, the age of the plants and the extent of secondary root growth. as wa ... | 1995 | 24169921 |
| callose synthesis in spirostanol treated carrot cells is not triggered by cytosolic calcium, cytosolic ph or membrane potential changes. | carrot (daucus carota l.) cell suspensions were treated with a spirostanol saponin from yucca. this saponin is an elicitor of callose synthesis. irrespectively of the mode of action of spirostanol on the callose synthase activity itself, the spirostanol-induced callose synthesis in carrot is not preceded by changes in membrane potential, cytosolic free calcium or cytosolic ph. the inability of modulators of cytosolic free calcium content (verapamil, nifedipine and br-a23187), egta and a proton p ... | 1995 | 8564297 |
| inheritance of chloroplast and mitochondrial dna in alloplasmic forms of the genus daucus. | the inheritance of mitochondrial (mt) and chloroplast (ct) dna in the progeny from interspecific crosses between the cultivated carrot (daucus carota sativus) and wild forms of the genus daucus was investigated by analysis of mt and ct rflps in single plants of the parental and filial generations. we observed a strict maternal inheritance of the organellar dnas in all interspecific crosses examined. previous studies on putative f2 plants from a cross between daucus muricatus x d. carota sativus ... | 1995 | 24169891 |
| mitochondrial dna diversity and male sterility in natural populations of daucus carota ssp carota. | mitochondrial variability was investigated in natural populations of wild carrot (daucus carota ssp carota) in different regions: south of france, greece, and various sites in the mediterranean basin and asia. total dna was digested with two restriction endonucleases (ecorv and hindiii) and probed with three mitochondrial dma-specific genes (coxi, atp6, and coxii). twenty-five different mitochondrial types were found in 80 analyzed individuals. thirteen mitotypes were found among the 7 french po ... | 1995 | 24169681 |
| association of multiple gtp-binding proteins with the plant cytoskeleton and nuclear matrix. | several types of gtp-binding proteins exist in plant cells. these include the ras-related low-molecular-weight monomeric gtp-binding proteins and the multi-subunit group which more closely resembles members of the mammalian heterotrimeric g-protein family. proteins belonging to both of these families are known to be involved in cell signalling events and have until recently been assumed to be associated predominantly with membranes. we have investigated the possibility that gtp-binding proteins ... | 1995 | 7741751 |
| biochemical, physiological, and molecular characterization of sucrose synthase from daucus carota. | sucrose synthase (ec 2.4.1.13) from carrot (daucus carota) is a tetramer with a molecular mass of 320 kd and subunits of 80 kd. the enzyme has a ph optimum of 7.0 (cleavage direction). maximal activities were measured at 55 degrees c. the km for suc was estimated as 87 mm and for udp as 0.39 mm. fructose acts as a noncompetitive inhibitor with an inhibition constant of 17.2 mm. in contrast, glucose inhibits carrot sucrose synthase uncompetitively with an inhibition constant of 4.3 mm. cdna clone ... | 1995 | 7784526 |
| the effects of mastoparan on the carrot cell plasma membrane polyphosphoinositide phospholipase c. | when [3h]inositol-labeled carrot (daucus carota l.) cells were treated with 10 or 25 microm wasp venom peptide mastoparan or the active analog mas-7 there was a rapid loss of more than 70% of [3h]phosphatidylinositol-4-monophosphate (pip) and [3h]phosphatidylinositol-4,5-bisphosphate (pip2) and a 3- and 4-fold increase in [3h]inositol-1,4-p2 and [3h]inositol-1,4,5-p3, respectively. the identity of [3h]inositol-1,4,5-p3 was confirmed by phosphorylation with inositol-1,4,5-p3 3-kinase and co-migra ... | 1995 | 7716245 |
| inositol(1,4,5)trisphosphate production in plant cells: stimulation by the venom peptides, melittin and mastoparan. | the ability of the amphiphilic peptides, melittin and mastoparan, to modulate the production of inositol(1,4,5)trisphosphate in cultured plant (daucus carota l.) cells was investigated. when added to intact cells melittin and mastoparan caused a rapid and dose-dependent increase in inositol(1,4,5)trisphosphate concentrations. in isolated protoplasts, inositol(1,4,5)trisphosphate levels were 12- to 16-fold higher than in the corresponding cells and neither melittin nor mastoparan was able to sign ... | 1994 | 7999106 |
| production and analysis of asymmetric hybrid plants between monocotyledon (oryza sativa l.) and dicotyledon (daucus carota l.). | asymmetric hybrid plants were obtained from fused protoplasts of a monocotyledon (oryza sativa l.) and a dicotyledon (daucus carota l.). x-ray-irradiated protoplasts isolated from a cytoplasmic malesterile (cms) carrot suspension culture were fused with iodoacetoamide-treated protoplasts isolated from a 5-methyltryptophan (5mt)-resistant rice suspension culture by electrofusion. the complementary recovered cells divided and formed colonies, which were then cultivated on regeneration medium suppl ... | 1994 | 24177855 |
| ammonium assimilation and the role of [gamma]-aminobutyric acid in ph homeostasis in carrot cell suspensions. | in vivo 15n nmr spectroscopy was used to monitor the assimilation of ammonium by cell-suspension cultures of carrot (daucus carota l. cv chantenay). the cell suspensions were supplied with oxygen in the form of either pure oxygen ("oxygenated cells") or air ("aerated cells"). in contrast to oxygenated cells, in which ammonium assimilation had no effect on cytoplasmic ph, ammonium assimilation by aerated cells caused a decrease in cytoplasmic ph of almost 0.2 ph unit. this led to a change in nitr ... | 1994 | 12232346 |
| high-performance liquid chromatographic determination of dietary fibre in raw and processed carrots. | an hplc method was developed to determine dietary fibre in carrots (daucus carota l.). primary hydrolysis of dietary fibre residue was performed with 12 m h2so4 for 2 h at 40 degrees c and secondary hydrolysis with 0.414 m h2so4 for 3 h at 100 degrees c. for the neutralization step prior to injection, ag4-x4 resin (bio-rad) was used. neutral monosaccharides were separated using an hpx-87p column (bio-rad). this method was applied for evaluation of the quantitative variation of dietary fibre cont ... | 1994 | 7921187 |
| chlorsulfuron resistance in daucus carota cell lines and plants:involvement of gene amplification. | daucus carota l. cell lines stably resistant to the herbicide chlorsulfuron (cs) have been isolated according to a stepwise selection. studies carried out during different selection steps show that the specific activity of the target enzyme acetohydroxyacid synthase (ahas) increases along with cs resistance. southern hybridization analysis performed with abrassica napus ahas probe in a cs highly-resistant cell line reveals the presence of a greatly amplifiedecori fragment of genomic dna. this in ... | 1994 | 24186104 |
| voltage-dependent calcium-permeable channels in the plasma membrane of a higher plant cell. | numerous biological assays and pharmacological studies on various higher plant tissues have led to the suggestion that voltage-dependent plasma membrane ca2+ channels play prominent roles in initiating signal transduction processes during plant growth and development. however, to date no direct evidence has been obtained for the existence of such depolarization-activated ca2+ channels in the plasma membrane of higher plant cells. carrot suspension cells (daucus carota l.) provide a well-suited s ... | 1994 | 8039493 |
| production of somatic hybrids between daucus carota l. and nicotiana tabacum. | protoplasts of a kanamycin-resistant (kr, nuclear genome), streptomycin-resistant (sr, chloroplast genome) and chlorophyll-deficient (a1, nuclear genome) nicotiana tabacum (kr-sa) cell suspension cultures or x-ray-irradiated mesophyll protoplasts of kanamycin- and streptomycin-resistant green plants (kr-sr) were fused with protoplasts of a cytoplasmic male-sterile (cms) daucus carota l. cell suspension cultures by electrofusion. somatic hybrid plants were selected for kanamycin resistance and th ... | 1994 | 24185885 |
| 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 ... | 1993 | 12231995 |
| 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 ... | 1993 | 8022945 |
| a cdna differentially expressed between embryogenic and nonembryogenic carrot (daucus carota l.) cells. | | 1993 | 8022926 |
| 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 ... | 1993 | 24248578 |
| 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 ... | 1993 | 8029337 |
| 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 ... | 1993 | 12231918 |
| 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 ... | 1993 | 8393642 |
| characterization of the non-specific lipid transfer protein ep2 from carrot (daucus carota l.). | the extracellular protein ep2 was previously identified as non-specific lipid transfer protein based on its cdna-derived amino acid sequence. here, the purification of the ep2 protein from the medium of somatic embryo cultures is described. after two cycles of ion-exchange and gel permeation chromatography, a single silver-stained protein band with an apparent molecular mass of 10 kda was observed on sds-page. this protein band was recognized by the antiserum raised against a ep2-beta-galactosid ... | 2006 | 8232259 |
| 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 ( ... | 1993 | 12231855 |
| 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 ... | 1993 | 24249074 |
| 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 ... | 1993 | 12231796 |
| 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 ... | 1993 | 8108498 |
| 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 ... | 1993 | 18609625 |
| 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 ... | 1993 | 8385897 |
| 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 ... | 1993 | 8490126 |
| 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 ... | 1993 | 28313777 |
| 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 ... | 1993 | 24196052 |
| 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 ... | 1993 | 11607356 |
| 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 ... | 1993 | 8278498 |
| 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 ... | 1992 | 16653250 |
| 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 ... | 1992 | 16653201 |
| 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 ... | 1992 | 24213361 |
| 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 ... | 1992 | 24178334 |
| 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 ... | 1992 | 16653062 |
| 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 ... | 1992 | 1396695 |
| 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 ... | 1992 | 16669096 |
| 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. | 1992 | 16669093 |
| 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 ... | 1992 | 24203204 |
| 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] ... | 1992 | 24203145 |
| 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 ... | 1992 | 1535801 |
| 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 ... | 1992 | 1368363 |
| 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 ... | 1992 | 24177979 |
| 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 ... | 1992 | 1544367 |
| 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 ... | 1992 | 1375313 |
| 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 ... | 1992 | 24213486 |
| 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.-). | 1992 | 24186789 |
| 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 ... | 1992 | 16668764 |
| 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 ... | 1992 | 16668745 |
| 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 ... | 1992 | 1541302 |
| 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 ... | 1992 | 24202587 |
| 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 ... | 1992 | 24186729 |
| 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 ... | 1991 | 24193528 |
| 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 ... | 1991 | 16668581 |
| 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 ... | 1991 | 24186530 |
| 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 ... | 1991 | 16668442 |
| 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 ... | 1991 | 24221667 |
| 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 ... | 1991 | 24213171 |
| 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 ... | 1991 | 24186342 |
| 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 ... | 1991 | 16668416 |
| 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 ... | 1991 | 24213074 |
| 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 ... | 1991 | 16668246 |
| 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 ... | 1991 | 24221496 |
| 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 ... | 1991 | 24213686 |
| 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 ... | 1991 | 16668093 |
| 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 ... | 1991 | 2065632 |
| 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 ... | 1991 | 16668049 |
| 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 ... | 1991 | 16668014 |
| 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 ... | 1991 | 16667947 |
| short-term treatment with cell wall degrading enzymes increases the activity of the inositol phospholipid kinases and the vanadate-sensitive atpase of carrot cells. | treating carrot (daucus carota l.) suspension culture cells with a mixture of cell wall degrading enzymes, driselase, resulted in an increase in the percentage of [(3)h]phosphatidylinositol bisphosphate. analysis of the lipid kinase activities in the isolated plasma membranes after whole cell treatment indicated that treatment with driselase (2% weight/volume; the equivalent of 340 units per milliliter of hemicellulase and 400 units per milliliter of cellulase activity) or treatment with hemicel ... | 1990 | 16667922 |
| somatic embryogenesis of carrot in hormone-free medium: external ph control over morphogenesis. | cultures of preglobular stage proembryos (pgsps) were initiated from mechanically wounded mature zygotic embryos of carrot, daucus carota, on a hormone-free, semisolid medium. these pgsps have been maintained and multiplied for extended periods without their progression into later embryo stages on the same hormone-free medium containing 1 mm nh4+ as the sole nitrogen source. sustained maintenance of cultures comprised exclusively of pgsps was dependent on medium ph throughout the culture period. ... | 1990 | 11541515 |