Publications

the effects of gelatin on aggregation of protoplasts from higher plants.	aggregation of protoplasts of allium fistulosum l., brassica chinensis l. and daucus carota l. was induced in great frequency with gelatin and early products of gelatin degradation. the optimal gelatin concentration was 2-5%. the aggregated protoplasts fused into groups and cell walls were formed around them in culture.	1973	24458819
[relationship between anthocyanin synthesis and activity of phenylalanine ammonia-lyase (pal) in callus cells of daucus carota].	two celllines from daucus carota callus were tested for phenylalanine ammonia-lyase activity. the white callus (dcw) has only 15% of the enzyme activity of the blue callus (dcb). the enzyme activity reaches a maximum value after a cultivation period of 21 days, whereas the maximum in anthocyanin content is reached after 28 days. we can demonstrate here a good correlation between one of the enzymes and the end product of the anthocyanin biosynthesis.the crude extract from dcw cells has no inhibit ...	1974	24458301
transfer of algal chloroplasts into protoplasts of higher plants.	polyethylene-glycol treatment of mixed suspensions of isolated protoplasts and of chloroplasts induces chloroplast uptake by the protoplasts. chloroplasts of algal origin (vaucheria dichotoma (l.) ag.) were transferred with high frequency into protoplasts of daucus carota l.	1974	24442619
alkaline β-fructofuranosidases of tuberous roots: possible physiological function.	alkaline invertase of roots of carrot (daucus carota l.) did not hydrolyze raffinose while the acid invertase from the same tissue showed with this sugar ca. 60% of the activity found with sucrose. the activity of the two invertases was inhibited by fructose to a different extent, the k i value being ca. 4×10(-2) m and 3×10(-1)m, respectively, for the alkaline and the acid invertases from the roots of both carrot and turnip (brassica rapa l.). it is proposed that fructose inhibition of acid inve ...	1974	24442377
the control of glycolysis in aged slices of carrot root tissue.	the possibility that the rate of glycolysis in aged slices of carrot (daucus carota l.) is controlled by the enzyme phosphofructokinase was examined, by changing the rate of metabolism, by supplying the tissue with potassium chloride, potassium phosphate and potassium citrate and measuring the subsequent changes in levels of metabolites. potassium chloride and potassium phosphate stimulate glycolysis, potassium citrate inhibits glycolysis and the associated changes in metabolites are consistent ...	1974	24442325
the pasteur effect in carrot root tissue.	the presence of a pasteur effect in aged discs of carrot (daucus carota l.) storage tissue and its apparent absence in fresh discs was confirmed. changes in the concentration of glycolytic intermediates have been determined, following the transfer of fresh and aged discs from air to nitrogen. in addition the changes in glycolytic intermediates associated with the ageing of the discs have also been measured. the results are analysed and interpreted to indicate that in aged discs the enzyme phosph ...	1974	24442324
development of tuberous roots and sugar accumulation as related to invertase activity and mineral nutrition.	sucrose storage in tuberous roots was not observed when the tissues had very high activities of acid invertase. high activities of the enzyme were always present in the roots at early stages of their development. in species where the activity of the enzyme decreased during root development, sucrose was stored. thus, acid invertase was undetectable in mature roots of carrots (daucus carota l.) where sucrose formed almost 80% of the dry matter. conversely, radish (raphanus sativus l.) and turnip ( ...	1974	24442198
intra-population genetic diversity of cultivated carrot (daucus carota l.) assessed by analysis of microsatellite markers.	intra-population variation of 18 cultivated carrot (daucus carota l. ssp. sativus) populations of diverse origins was evaluated using codominant microsatellite (ssr) markers. using 27 genomic and est-derived ssr markers, 253 alleles were identified with a mean 9.4 alleles per marker. most of the alleles (60.5%) were rare i.e., with the frequency ≤ 0.05 while only 3.95% of alleles occurred with frequency > 0.6. est-derived ssr markers were less polymorphic than genomic ssr markers. differences in ...	2013	24432327
[changes of glyco- and phospholipid contents during leaf senescence].	the glyco- and phospholipid levels in green, green-yellow and yellow leaves of impatients balsamina l., daucus carota l. and cucurbita pepo l. were determined on a leaf area basis. in fagus silvatica l. leaves the kinetics of lipid breakdown during autumnal senescence was analysed. it was shown that yellow tissues still contain 40% to 50% of galactolipids and 50% to 60% of phospholipids present in green tissues. in the early stages of senescence of autumnal fagus leaves we found a more rapid dec ...	1976	24430693
release of hydrolytic enzymes from the cell walls of intact and disrupted carrot callus tissue.	the effect of ionic strength and ph on the solubility of acid invertase (e.c. 3.2.1.26.) and α-glucosidase (e.c. 3.2.1.20.) from carrot daucus carota l. tissue cultures is presented. the action of these two factors on disrupted tissue is contrasted with the effects of the same treatment on the solubility of these enzymes from intact tissue. the results are discussed in terms of a unified theory on the solubility behaviour of acid invertase and other hydrolytic enzymes in plant cells.	1975	24430368
on the mechanism of the uptake of vaucheria chloroplasts by carrot protoplasts treated with polyethylene glycol.	chloroplasts from the alga, vaucheria dichotoma (l.) ag., are taken up into protoplasts of carrot (daucus carota l.) during polyethylene-glycol treatment. since chloroplasts are found with equal frequency in uni- and multinucleate protoplasts, chloroplast uptake does not depend on protoplast fusion. however, higher frequencies of chloroplast uptake are observed when experimental conditions favor greater aggregation of protoplasts. the intracellular localization of chloroplasts is confirmed by el ...	1976	24424824
morphometric measurements of daucus carota suspension culture cells.	standard stereologic methods have been applied to electron micrographs of daucus carota l. suspension culture cells. the relative frequencies of the different membrane systems within the cells have been determined and compared with published data form mature leaf cells.	1977	24420523
purification and substrate specifities of hydroxycinnamate: coa ligase from anthocyanin-containing and anthocyanin-free carrot cells.	callus cells of daucus carota l. have different phenylpropanoid pathways depending on the medium composition. cells propagated on a medium with gibberellic acid do not accumulate cyanidin but incorporate [(14)c]phenylalanine into chlorogenic acid at a high rate. cells grown on a medium free of gibberellic acid accumulate cyanidin in very large amounts. we here describe partial purification of hydroxycinnamate: coa ligase, and its properties in these two cell lines. the enzymes extracted from the ...	1977	24420100
synthesis of phenylalanine ammonia-lyase in anthocyanin-containing and anthocyanin-free callus cells of daucus carota l.	when callus cells of daucus carota are grown on a medium containing gibberellic acid (ga3) in a physiological concentration of 3x10(-6) m the cells cease to accumulate anthocyanins. this anthocyanin-free cell line has a very low activity of phenylalanine ammonia-lyase. after density labelling with d2o an intensive de novo synthesis of the phenylalanine ammonia-lyase (e.c. 4.3.1.5; pal) in the anthocyanin-containing cells does occur. 58% of the c-bound h-atoms are replaced by deuterium. the antho ...	1977	24419894
relation between auxin autotrophy and tryptophan accumulation in cultured plant cells.	auxin autotrophy was studied in cultured carrot (daucus carota l.), tobacco (nicotiana tabacum l.), and potato (solanum tuberosum l.) cell lines. of 10 carrot lines resistant to 5-methyltryptophan (5mt), which accumulate free tryptophan (trp) because of an altered control enzyme, 5 were auxinautotrophic while the normal parent line was not. carrot lines selected from the same parent line as resistant to other amino-acid analogs were not auxinautotrophic, like the parent. the only 5mt-resistant p ...	1977	24419686
regulation of lysine and threonine synthesis in carrot cell suspension cultures and whole carrot roots.	aspartokinase (ec 2.7.2.4), homoserine-dehydrogenase (ec 1.1.1.3) and dihydrodipicolinic-acid-synthase (ec 4.2.1.52) activities were examined in extracts from 1-year-old and 11-year-old cell suspension cultures and whole roots of garden carrot (daucus carota l.). aspartokinase activity from suspension cultures was inhibited 85% by 10 mm l-lysine and 15% by 10mm l-threonine. in contrast, aspartokinase activity from whole roots was inhibited 45% by 10 mm lysine and 55% by 10 mm threonine. this dif ...	1978	24414879
oleosomes (spherosomes) from daucus carota suspension culture cells.	isolated oleosomes from daucus carota l. cells are lipid droplets consisting mainly of triacylglycerols (>97%) and very little protein (1-2%). the boundary between the lipid phase and the cytosol, which is visible on electron micrographs, is not built up by a true phospholipid-containing unit or half unit membrane. enzymatic activities of lipid metabolism were not found to be associated with oleosomes with the exception of very low (contaminating) acyl-coa:1,2-diacylglycerol acyltransferase (ec ...	1978	24414559
lipids, lipid turnover, and phospholipase d in plant suspension culture cells (daucus carota).	the lipid pattern of daucus carota l. suspension culture cells and other plant cell strains was analyzed. phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, and triacylglycerol were the main components. the characteristic plastidal and mitochondrial lipids could also be identified. all strains tested exhibited a phospholipase d activity. several lipid precursors were found to be well utilized by the cells and to be special markers for certain lipids or parts of the lipid molecu ...	1978	24414107
isolation and identification of substances inducing formation of tracheary elements in cultured carrot-root slices.	the roots of a carrot (daucus carota l.) cultivar, kuroda-gosun, contain active substances causing formation of tracheary elements in cultured root phloem slices. in the roots of another carrot cultivar, hokkaidô-gosun, such substances could not be detected but when root-phloem slices of this cultivar were cultured in the light, active substances were produced in the tissue. from the behavior in thinlayer chromatography and data from gas chromatography and mass spectrometry, the major active sub ...	1978	24413942
the influence of gibberellic acid on reassociation kinetics of dna of daucus carota l.	carrot dna, extracted from the tap root of untreated and gibberellic acid (ga3)-treated plants and of different varieties, was analyzed by reassociation kinetics. differences due to ga3 treatment appear mainly in the intermediate repeated dna region. differences in approximately the same region are found using carrot dna of different varieties, which also show differences in the slow reassociating sequences. by hybridizing a "family" of the "unique" dna range with dna obtained from ga3-treated p ...	1978	24408253
changing fatty acid composition during somatic embryogenesis in cultures of daucus carota.	the fatty acid composition of five embryo stages following the induction of embryogenesis in cultures of daucus carota have been studied. quantitative rather than qualitative changes in fatty acid content were observed, although globular embryos do possess some fatty acids of long (c 20 and above) chain length not observed in earlier or later stages in development. the major fatty acids present were c 16:0, 18:0, 18:1, 18:2 and 18:3.	1979	24407389
transfer of organelles of the alga chlamydomonas reinhardii into carrot cells by protoplast fusion.	a mutant of chlamydomonas reinhardii which lacks a cell wall was fused with daucus carota protoplasts using polyethylene glycol and the resulting fusion products were cultured. fusion involved integration of chlamydomonas and carrot plasma membranes and the release of algal organelles into the carrot cytoplasm. chlamydomonas basal bodies, nuclei and chloroplasts were frequently observed in the fusion products. cultured fusion products regenerated cell walls and divided; most chlamydomonas organe ...	1979	24407323
effect of pectin methylesterase on carrot (daucus carota) juice cloud stability.	to determine the effect of residual enzyme activity on carrot juice cloud, 0 to 1 u/g pectin methylesterase (pme) was added to pasteurized carrot juice. cloud stability and particle diameters were measured to quantify juice cloud stability and clarification for 56 days of storage. all levels of pme addition resulted in clarification; higher amounts had a modest effect in causing more rapid clarification, due to a faster increase in particle size. the cloud initially exhibited a trimodal distribu ...	2014	24401030
inheritance and mapping of mj-2, a new source of root-knot nematode (meloidogyne javanica) resistance in carrot.	root-knot nematodes limit carrot production around the world by inducing taproot forking and galling deformities that render carrots unmarketable. in warmer climates, meloidogyne javanica and meloidogyne incognita are most prevalent. in f2 and f3 progeny from the cross between an asian carrot resistant to m. javanica, pi 652188, and a susceptible carrot, resistance response was incompletely dominant with a relatively high heritability (h (2) = 0.78) and provided evidence for a single gene, desig ...	2014	24336925
combating photooxidative stress in green hairy roots of daucus carota cultivated under light irradiation.	the light-dependent generation of active oxygen species, which can disrupt normal metabolic process of plant, is termed as photo-oxidative stress. plants are equipped with enzymatic and non-enzymatic antioxidative defence system to reduce the effect of such stress. hairy root culture of daucus carota when cultivated under continuous illumination (250 μmol m(-2)s(-1)) turned green. to know the reason behind that and photo-oxidative stress response in green hairy roots, activities of several antio ...	2014	24331434
variation of the chemical composition and antimicrobial activity of the essential oils of natural populations of tunisian daucus carota l. (apiaceae).	the essential oils of daucus carota l. (apiaceae) seeds sampled from ten wild populations spread over northern tunisia were characterized by gc-fid and gc/ms analyses. in total, 36 compounds were identified in the d. carota seed essential oils, with a predominance of sesquiterpene hydrocarbons in most samples (22.63-89.93% of the total oil composition). the main volatile compounds identified were β-bisabolene (mean content of 39.33%), sabinene (8.53%), geranyl acetate (7.12%), and elemicin (6.26 ...	2013	24327447
biosynthesis of myo-inositol and its role as a precursor of cell-wall polysaccharides in suspension cultures of wild-carrot cells.	the biosynthesis of myo-inositol (mi) and its role as a precursor of cell-wall polysaccharides was studied in supension cultures of wild carrot (daucus carota l.) cells. suspension cultures, grown in the presence or absence of 2,4-dichlorophenoxyacetic acid for 7 and 14d were incubated with [u-(14)c]glucose and [2-(3)h]mi in the presence of different concentrations of unlabeled mi. synthesis of [(14)c]mi from [u-(14)c]glucose occurred under all conditions. the amount of mi synthesized from gluco ...	1979	24317946
biosynthesis of cell-wall polysaccharides in cultured carrot cells.	biosynthesis of the cell wall in carrot cells (daucus carota l.) cultured in a synthetic liquid medium was studied by measuring the incorporation of radioactive glucose and myo-inositol (mi). when the cells were fed with [(14)c]glucose in the presence of 0.01% mi, the label soon appeared in the neutral sugars in the cell wall but little radioactivity was found in the uronic-acid residues even after a prolonged incubation. on the other hand, radioactivity derived from [(3)h]mi was found to be dis ...	1979	24317945
relationship of indole-3-acetic acid and tryptophan concentrations in normal and 5-methyltryptophan-resistant cell lines of wild carrots.	a 5-methyltryptophan(5-mt)-resistant cell line of wild carrot (daucus carota l.), w001, that exhibited auxin-independent callus growth, was found to accumulate indole-3-acetic acid (iaa) and tryptophan (trp). anthranilate-synthetase activity in w001 cell extract was less sensitive to feedback inhibition by trp than in the original 5-mt-sensitive cell lines. it is hypothesized that the resistant enzyme allowed more trp synthesis and accumulation which, in turn, affected the iaa concentration in t ...	1979	24317760
somatic hybridisation of daucus carota and d. capillifolius by protoplast fusion.	protoplasts isolated from cultured cells of albino carrot (daucus carota) and normal green d. capillifolius were fused by polyethylene glycol. selection of somatic hybrid plants was based on the restoration of photosynthetic function in hybrids. green plantlets selected from embryo cultures were characterized on the basis of leaf morphology. the interspecific protoplast fusion resulted in green plants with leaves which were intermediate between those of the parents. the somatic hybrids between o ...	1977	24317689
liposome-mediated transfer of bacterial rna into carrot protoplasts.	the uptake of liposome-encapsulated e. coli [(3)h]rna by carrot (daucus carota l.) protoplasts was examined. [(3)h]rna extracted from protoplasts that had been incubated with [(3)h]rna-containing, large, unilamellar lipid vesicles (liposomes) obtained by ether infusion, and examined by sucrose gradient centrifugation and formamide-polyacrylamide gel electrophoresis, appeared substantially degraded, with a total elimination of 23s rna and a partial loss of 16s rna. in contrast, no breakdown of th ...	1979	24317562
quantitative studies of embryogenesis in normal and 5-methyltryptophan-resistant cell lines of wild carrot : the effects of growth regulators.	the frequency of embryo formation was determined in normal and 5-methyltryptophan-resistant (5-mt(r)) cell lines of wild carrot (daucus carota l.) grown in the presence or absence of 2-isopentenyladenine (2-ip) and 2,4-dichlorophenoxyacetic acid (2,4-d). 2-ip stimulated the intitation of embryo formation and also accelerated embryo development. 2.4-d inhibited embryo differentiation at several stages: at 0.1 mg/l, it stopped regeneration at the earliest stage, resulting in callus growth instead ...	1979	24311038
composition of suberin-associated waxes from the subterranean storage organs of seven plants : parsnip, carrot, rutabaga, turnip, red beet, sweet potato and potato.	the waxes associated with the suberin in the periderm of the underground storage organs of parsnip (pastinaca sativa l.), carrot (daucus carota l.), rutabaga (brassica napobrassica mill.), turnip (brassica rapa l.), red beet (beta vulgaris l.), sweet potato (ipomoea batatas l.) and potato (solanum tuberosum l.) were isolated, fractionated into hydrocarbon, wax ester, free fatty alcohol and free fatty acid fractions, and analyzed by combined gas chromatography and mass spectrometry. the amount of ...	1980	24310190
5-fluorouracil resistance in carrot cell cultures : its use in studying the interaction of the pyrimidine and arginine pathways.	physiological studies of 5-fluorouracil (5-fu)-resistant cell line of wild carrot (daucus carota l.), f5, showed that this variant is also resistant to 5-fluorouridine, but is as sensitive to 6-azauracil as the 5-fu-sensitive parent line, woo1c. high levels of exogenous uracil, uridine, and thymine are slightly toxic to f5, but not to woo1c. 5-fu sensitivity in woo1c cannot be reversed by bases and nucleosides; bases like uracil and thymine even increase 5-fu toxicity. no substantial differences ...	1980	24310143
identification of hairy root loci in the t-regions of agrobacterium rhizogenes ri plasmids.	agrobacterium rhizogenes induces root formation at the wound site of inoculation in plants and inserts a fragment of its plasmid (ri) into the plant nuclear dna. parts of the transferred region (t-region) of the ri plasmid of a. rhizogenes strain a4 or 8196 are cloned in escherichia coli. insertions of the e. coli lacz coding region into the hybrid plasmids were made in vivo using transduction by minimu. twenty insertions localized in the tl-dna of pria4 (or pri1855) and 2 inserts in the t-dna o ...	1986	24307326
dihydrofolate reductase from daucus carota cell suspension cultures: purification, molecular and kinetic characterization.	the purification of dihydrofolate reductase (5, 6, 7, 8 tetrahydrofolate: nadp(+) oxidoreductase, e.c.: 1.5.1.3) from daucus carota to apparent homogeneity, is described. the enzyme is a soluble protein with a molecular weight of 183 000±2 500, composed of identical subunits of 58 400±1 000. the enzyme is only weakly recognized by antibodies against human dhfr. the carrot dhfr is characterized by a ph optimum of 5.9, km values for dihydrofolate and nadph of 3.7 μm and 2.2 μm, respectively and a ...	1985	24306990
role of auxin and sucrose in the differentiation of sieve and tracheary elements in plant tissue cultures.	the differentiation of sieve and tracheary elements was studied in callus culture of daucus carota l., syringa vulgaris l., glycine max (l.) merr., helianthus annuus l., hibiscus cannabinus l. and pisum sativum l. by the lacmoid clearing technique it was found that development of the phloem commenced before that of the xylem. in not one of the calluses was differentiation of tracheary elements observed in the absence of sieve elements. the influence of indole-3-acetic acid (iaa) and sucrose was ...	1980	24306691
binding of colchicine to a soluble fraction of carrot cells grown in suspension culture.	the binding of [(3)h]colchicine to soluble component prepared from carrot (daucus carota l.) cells in suspension culture was assayed by the diethylaminoethyl(deae)-cellulose powder method. the binding activity was very labile and the time course of the binding indicated that the colchicine-bound complex was also unstable. the reaction was enhanced by vinblastine but lumicolchicine had no effect. the optimum temperature for the reaction was 30° c, and the colchicine binding constant was calculate ...	1980	24306371
a clonal analysis of anthocyanin accumulation by cell cultures of wild carrot.	the accumulation of anthocyanin by clones and subclones from a cell suspension culture of wild carrot (daucus carota l.) has been measured under standard conditions. clones which accumulate low amounts of anthocyanin were shown, by recloning after maintenance by serial passage, to have become heterogenous and to contain cells with increased accumulation of anthocyanin. there appears to be a maximum amount of anthocyanin that clones can accumulate. clones which accumulate the maximum amount of an ...	1980	24306302
anthocyanin accumulation and pal activity in a suspension culture of daucus carota l. : inhibition by l-α-aminooxy-β-phenylpropionic acid and t-cinnamic acid.	cells of daucus carota grown in a liquid medium produced large amounts of cyanidin as the only flavonoid aglycon. after inoculation in fresh medium a maximum activity of phenylalanine ammonia lyase (pal; ec 4.3.1.5) was observed within 24 h. l-α-aminooxy-β-phenylpropionic acid (l-aopp), thought to be a competitive inhibitor of pal, inhibited cyanidin accumulation up to 80%. in order to study the regulatory role of pal, the effects of l-aopp and t-cinnamic acid, the product of the deamination of ...	1980	24306300
increase in anthocyanin yield from wild-carrot cell cultures by a selection system based on cell-aggregate size.	wild-carrot (daucus carota l.) cell cultures were screened to yield small (less than 63 μm) or large (greater than 170 μm) cell aggregates which were then subcultured. cultures of the small-size class had a higher, those of the large-size class a lower anthocyanin yield than the unscreened culture. this relationship became accentuated with an increasing number of passages with screening prior to subculture. at the end of six months (12 passages), the pigment yield of the small-size class was tri ...	1980	24306253
formation of norisoprenoid flavor compounds in carrot (daucus carota l.) roots: characterization of a cyclic-specific carotenoid cleavage dioxygenase 1 gene.	carotenoids are isoprenoid pigments that upon oxidative cleavage lead to the production of norisoprenoids that have profound effect on flavor and aromas of agricultural products. the biosynthetic pathway to norisoprenoids in carrots (daucus carota l.) is still largely unknown. we found the volatile norisoprenoids farnesylacetone, α-ionone, and β-ionone accumulated in nairobi, rothild, and purple haze cultivars but not in yellowstone and creme de lite in a pattern reflecting their carotenoid cont ...	2013	24289159
daucus carota cells contain a dihydrofolate reductase: thymidylate synthase bifunctional polypeptide.	dihydrofolate reductase (dhfr) and thymidylate synthase (ts) activities from cell suspension cultures of daucus carota were shown to copurify on (nh4)2so4 fractionation, deae sephadex and methotrexate-sepharose affinity chromatography and to share approximately the same mr(183 kda and 185 kda respectively) as judged by gel filtration on sephacryl s-200.the copurified protein migrated as a single band on polyacrylamide gel electrophoresis under denaturing conditions.both activities could be elute ...	1988	24277564
liposome-mediated delivery of dna to carrot protoplasts.	the encapsulation of dna within liposomes and subsequent fusion of the liposomes with carrot (daucus carota l.) protoplasts were examined to determine optimum conditions for effective liposome-mediated delivery of dna to protoplasts. escherichia coli [(3)h]dna could be encapsulated with 50% efficiency using encapsulation volumes as low as 0.5 ml. incorporation of liposome-encapsulated [(3)h]dna by carrot protoplasts increased linearly for 2.5 h, and increasing the ratio of protoplasts to liposom ...	1981	24276711
quantitation of gibberellins and the metabolism of [(3)h]gibberellin a 1 during somatic embryogenesis in carrot and anise cell cultures.	in a carrot (daucus carota l.) cell line lacking the ability to undergo somatic embryogenasis, and in carrot and anise (pimpinella anisum l.) cell lines in which embryogenesis could be regulated by presence or absence of 2,4-dichlorophen-oxyacetic acid (2,4-d), in the medium (+2,4-d=no embryogenesis,-2,4-d=embryo differentiation and development), the levels of endogenous gibberellin(s) (ga) were determined by the dwarfrice bioassay, and the metabolism of [(3)h]ga1 was followed. embryos harvested ...	1982	24271967
changes in non-cellulosic cell-wall polysaccharides during the growth of carrot cells in suspension cultures.	the cell-wall composition of carrot (daucus carota l.) cells has been studied during their growth in suspension culture. pectic and hemicellulosic polymers were fractionated according to molecular size by a sepharose 4b column. polyuronides in the pectic fraction were resolved into high- and low-molecular-weight components. the low-molecular-weight polyuronides were relatively free of neutral sugars and showed a marked increase during the growth of the cell wall. hemicellulosic polysaccharides w ...	1983	24264546
inhibition of flavonoid biosynthesis by gibberellic acid in cell suspension cultures of daucus carota l.	in carrot cells (daucus carota l.), cultured in the presence of gibberellic acid, anthocyanin synthesis is blocked at the level of chalcone synthase. by feeding suitable precursors for anthocyanins (naringenin, eriodictyol, dihydroquercetin) biosynthesis of cyanidin glycosides can be restored. after addition of these substrates to the culture medium in the presence of gibberellic acid, the activity of chalcone synthase remained as low as in the control without precursors. the highest increase in ...	1984	24258782
pectic polysaccharides in carrot cells growing in suspension culture.	pectic polysaccharides in the cell wall of suspension-cultured carrot cells (daucus carota l.) were fractionated into high- and low-molecular-weight components by molecular-sieve chromatography with a sepharose 4b column. during the phase of cell-wall expansion, the relative content of low-molecular-weight polymers rapidly increased. electrophoretic analyses of these fractions showed that the high-molecular-weight components were largely composed of neutral and weakly acidic polymers while the l ...	1984	24258676
inactivation of aphidicolin by plant cells.	plant cells are endowed with an aphidicolin inactivating activity. data on cultured cells show that the rate of inactivation depends on the cell type, daucus carota cells being the most effective among the other tested materials (oryza sativa and nicotiana plumbaginifolia). also germinating seedling of haplopappus gracilis and of citrullus vulgaris inactivate aphidicolin.inactivation, which may lead to unexpected results when a prolonged incubation with the drug is required, as in the case of th ...	1983	24258125
inhibition of cultured cell growth by tungstate and molybdate.	the growth of suspension cultured cells of nicotiana tabacum (tobacco) was inhibited completely by 100 μm tungstate. even though molybdate reversed the tungstate inactivation of nitrate reductase activity, the growth inhibition was not reversed. the growth inhibition of n. tabacum, daucus carota, glycine max and solanum tuberosum suspension cultured cells by tungstate was similar in media with or without amino acids as a source of reduced nitrogen. only in the case of g. max was a slight reversa ...	1983	24257847
comparative studies of the phytochrome system in cell cultures from different plants.	phytochrome contents have been assayed in vivo in cell suspension cultures of petroselinum hortense, daucus carota and glycine max. after transferring the cells to fresh medium phytochrome increased in parallel with the increase in cell number, whereas the amount of phytochrome per cell remained constant. the rate of phytochrome reaccumulation after pretreatment with 15 h red light was very similar in all three systems (2.8-3.6 δ(δe) 10(-5)/h). dark reversion and a fast and slow pfr destruction ...	1982	24257714
influence of a loblolly pine (pinus taeda l.). culture medium and its components on growth and somatic embryogenesis of the wild carrot (daucus carota l.).	a new culture medium, originally designed and shown to grow cell suspensions from a variety of loblolly pine (pinus taeda l.) explants, was used to study growth and somatic embryogenesis of the wild carrot (daucus carota l.) in cell suspensions. the new loblolly pine medium (lm) differed from the standard wild carrot medium (wcm) in having very low ca(2+), very high mg(2+), and enrichment with po inf4 (sup3-) and microelements. when wcm was altered to contain levels of ca(2+) or ca(2+) and mg(2+ ...	1985	24254074
effect of brassinosteroid on cell division and enlargement in cultured carrot (daucus carota l.) cells.	when added at 3.10(-6) mm to auxin-starved suspension cultured carrot (daucus carota l.) cells, the steroid hormone 24-epibrassinolide (br) induces cell enlargement but not cell division.this is at variance from the effect of 2,4-d which, in the same experimental conditions, restores cell division without having any effect on cell enlargement.furthermore, in the tested experimental conditions, the effect of br is dominant over the effect of 2,4-d when the two hormones are simultaneously supplied ...	1985	24253747
benomyl: a broad spectrum fungicide for use in plant cell and protoplast culture.	the systemic fungicide methyl-1-(butylcarbamoyl)-2-benzimidazole carbamate (benomyl), is a broad spectrum fungicide. benomyl at concentrations up to 50 mg/l does not inhibit the growth of suspension cultures ofnicotiana tabacum, datura innoxia, daucus carota, glycine canescens, andsolanum tuberosum nor growth ofn. tabacum orn. plumbaginifolia protoplasts if benomyl is dissolved by autoclaving or boiling. addition of benomyl dissolved in dimethyl sulfoxide results in a visible toxicity. benomyl, ...	1985	24253743
immobilization of plant protoplasts: viability studies.	protoplasts of daucus carota ca68 and catharanthus roseus have been immobilized by entrapment in gelforming polysaccharides (kappa-carrageenan, agarose and alginate). uniform spherical beads of carrageenan and agarose containing the protoplasts have been prepared by utilizing an inert hydrophobic phase (vegetable oil). the entrapped protoplasts are viable and stabilized towards osmotic shock by the polymeric backbone. standard methods have been used to study the viability and integrity of the en ...	1985	24253638
use of an electrochemical technique to study plasmamembrane redox reactions in cultured cells of daucus carota l.	by exploiting the electron transfer reactions of ferricyanide-ferrocyanide at a gold electrode, an electrochemical technique was devised and successfully employed for the measurement of extracellular ferricyanide reduction or ferrocyanide oxidation by carrot (daucus carota l.) cells grown in suspension culture. this technique eliminated problems of cell damage and insensitivity encountered when these activities are measured spectrophotometrically in magnetically stirred cell suspensions. cells h ...	1984	24253577
stimulation of carrot somatic embryogenesis by proline and serine.	serine and proline, when added in a wide range of concentrations to daucus carota cultures during pre-growth in the presence of 2,4-d(2,4-dichlorophenoxyacetic acid), extended in time and quantity the mitotic divisions and stimulated significantly the number of embryos regenerated when the hormone subsequently was omitted from the medium. a specific effect of these amino acids on regeneration is suggested, since proline (as hydroxyproline) and serine are the two major constituents of the cell wa ...	1984	24253519
developmental regulation of polyamine metabolism in growth and differentiation of carrot culture.	polyamine levels and the activities of two polyamine biosynthetic enzymes, arginine decarboxylase (ec 4.1.1.19) and s-adenosylmethionine decarboxylase (ec 4.1.1.50), were determined during somatic embryogenesis of carrot (daucus carota l.) cell cultures. embryogenic cultures showed severalfold increases in polyamine levels over nondifferentiating controls. a mutant cell line that failed to form embryos but grew at the same rate as the wild-type line also failed to show increases in polyamine lev ...	1984	24253270
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
a parenchymatic medium solidifier for plant in vitro culture.	a new material for the solidification of liquid culture media was prepared from plant parenchyma tissues by mechanical subdivision, solute extration and dessication from ethanol. it is suitable for in vitro culture and propagation of callus as well as shoot tip cultures. the following plant materials have been grown by means of the new medium solidifier: shoot cultures of betula pendula roth, gerbera jamesonii h. bolus ex hook and floribunda rose "triumph", callus tissues of daucus carota l. and ...	1987	24248936
factors affecting protoplast electrofusion efficiency.	the electrofusion efficiency of protoplasts isolated from a carrot (daucus carota) suspension culture was increased by treatment with 0.1 mg/ml lysolecithin, 2.5% dimethylsulfoxide (dmso), or 0.5 mm ca(2+). the lysolecithin and dmso treatments substantially increased protoplast lysis, whereas calcium treatment did not. the enzymes used for protoplast isolation were also found to have a dramatic effect on the efficiency of fusion. a mixture of cellulysin and driselase led to a two-fold enhancemen ...	1987	24248839
transient expression of electroporated dna in monocotyledonous and dicotyledonous species.	transient expression of electroporated dna was monitored in protoplasts of several monocot and dicot species by assaying for expression of chimeric chloramphenicol acetyltransferase (cat) gene constructions. expression was obtained in the dicot species of daucus carota, glycine max and petunia hybrida and the monocot species of triticum monococcum, pennisetum purpureum, panicum maximum, saccharum officinarum, and a double cross, trispecific hybrid between pennisetum purpureum, p. americanum, and ...	1987	24248756
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
methotrexate and aminopterin effects on growth and regeneration in daucus carota.	daucus carota l., callus was cultured on various levels of the folate analogs, methotrexate (4-amino-10-methylfolic acid, amethopterin) and aminopter in (4-aminofolic acid). callus growth was inhibited as analog concentrations were increased from 0.01 μm to 10 μm. methotrexate concentrations in excess of 10 μm were lethal. in contrast, concentrations of aminopterin in the range of 10 to 100 μm resulted in renewed growth and somatic embryogenesis leading to plant regeneration. this plant regenera ...	1987	24248451
marker proteins for embryogenic differentiation patterns in pea callus.	polypeptide pattern alterations during somatic embryogenesis were investigated using callus cultures of two pisum sativum genotypes. both genotypes show the formation of two different callus lines from the same explant after six to eight weeks in culture: a nodular yellowish callus line, which forms somatic embryoids in suspension cultures (e(+)) and a white compact callus line with no regenerative capacity (e(-)). the cytosol proteins of the two different callus lines were separated in a semi-p ...	1987	24248449
the effect of fluorescent labeling on calcium-induced fusion of fusogenic carrot protoplasts.	various fluorescent compounds - carboxyfluorescein, scopoletin, fluorescein isothiocyanate (fitc), rhodamine b isothiocyanate (ritc), rhodamine 123, and rhodamine b ethyl ester - were used to study their effects on calcium-induced fusion of fusogenic carrot (daucus carota l.) protoplasts. these protoplasts normally fused at a high percentage (50-60%) in response to 10 mm calcium, ph 6.0; however, if cells had been labeled with scopoletin, fitc, or ritc, fusion was greatly reduced. in contrast, l ...	1986	24248239
selection of daucus carota somatic hybrids using drug resistance markers and characterization of their mitochondrial genomes.	protoplasts from different daucus carota l. cell strains carrying resistance to glyphosate, 5-methyltryptophan, sodium selenate or selenocystine were fused in three combinations using dextran. clones were selected for both of the resistances carried by the individual parental strains in medium with both inhibitors. no doubly resistant colonies formed from unfused controls or from protoplasts from each individual parental strain alone. suspension cultures from the selected clones contained predom ...	1986	24248022
measurement of endogenous aba levels in chilled somatic embryos of carrot by immunoassay.	somatic embryos of carrot, daucus carota l. 'royal chantenay', were chilled at 4°c for the last 3 days of development in order to harden torpedo stage embryos to increase embryo survival during desiccation. aba levels in chilled and non-chilled embryos were measured using a polyclonal radioimmunoassay and a monoclonal enzyme-linked immunosorbent assay (elisa). the monoclonal elisa is the preferred technique due to superior sensitivity and specificity. aba levels, measured by either technique, we ...	1988	24241882
a rapid method for purification of organelles for dna isolation: self-generated percoll gradients.	self-generated percoll gradients have been used for rapid purification of crude chloroplasts and mitochondria, obtained by common differential centrifugation techniques. such purified organelles were used for isolating dna from safflower (carthamus tinctorius l.), carrot (daucus carota l.), various solanaceae, and numerous somatic hybrids. the method is simple, has the advantage of not requiring dnase, and is particularly well suited when only limited amounts of aseptically grown shoots are avai ...	1988	24241541
t-dna length variability in mannopine hairy root: more than 50 kilobasepairs of pri t-dna can integrate in plant cells.	independent carrot (daucus carota) hairy root lines were established by inoculation of discs taken from the same carrot with agrobacterium rhizogenes 8196 and a. tumefaciens c58c1(pri8196) carrying pri8196. several lines were compared with respect to t-dna length. one of them was found to have integrated sequences covering more than 50 kbp of the ri plasmid.	1988	24241540
detoxification of n-(phosphonoacetyl)-l-aspartate by carrot cells in suspension culture.	in bacterial and mammalian cells, n-(phosphonoacetyl)-l-aspartate (pala) suppresses growth by strongly inhibiting aspartate transcarbamoylase (atcase; ec 2.1.3.2), a key enzyme of the pyrimidine biosynthetic pathway. at a concentration that would suppress growth in mammalian or bacterial cells, and that is nearly a million-fold greater than the inhibition constant (k i ) for atcase in carrot (daucus carota) seedling extracts, pala does not suppress growth of carrot cells in suspension culture. t ...	1985	24241524
effect of exogenous amino acids on the intracellular content of proline and other amino acids in daucus carota cells.	the effect of tryptophan on the biosynthesis of proline has been investigated. cells of daucus carota grown in b5 medium supplemented with 5×10(-4)m tryptophan acquired the ability to grow in the presence of inhibitory concentrations of azetidine-2-carboxylic acid, an analog of proline. when trp was added to carrot cell cultures at sub-growth inhibiting concentrations, overproduction of intracellular free proline was observed. an increase was also observed for lys, his, ala, leu and phe. likewis ...	1989	24233368
carrot (daucus carota) hypocotyl transformation usingagrobacterium tumefaciens.	daucus carota hypocotyl sections were transformed withagrobacterium tumefaciens lba4404 containing camv 35s promoter, β-glucuronidase coding sequence and the nopaline synthase (nos) poly adenylation sequences in bin 19. sliced sterile seedling hypocotyl segments were preincubated for 2 days, co-cultivated withagrobacterium for an additional 2 days, and then transferred to medium containing 100ug/ml of kanamycin and 400ug/ml carbenicillin. in 6 weeks kanamycin resistant calli were obtained in 5.8 ...	1989	24233274
stimulation ofdaucus carota somatic embryogenesis by inhibitors of ethylene synthesis: cobalt and nickel.	the effects of co(2+) and ni(2+) on ethylene production and somatic embryogenesis by carrot (daucus carota l.) cell cultures were studied. at concentrations of 10 μm to 50 μm, cocl2 effectively inhibited ethylene production by embryogenic cultures and significantly stimulated somatic embryogenesis. the observed increase of embryo number was proportional to the inhibition level of ethylene production. however, cocl2 had no effect when ethephon was supplied. nickel also reduced ethylene production ...	1989	24233099
the uptake of acylated anthocyanin into isolated vacuoles from a cell suspension culture of daucus carota.	anthocyanin-containing vacuoles were isolated from protoplasts of a cell suspension culture of daucus carota. the vacuoles were stable for at least 2 h as demonstrated by the fact that they showed no efflux of anthocyanin. the uptake of radioactively labelled anthocyanin was time-dependent with a ph optimum at 7.5, and could be inhibited by the protonophore carbonylcyanide m-chlorophenylhydrazone. furthermore, the transport was specific, since vacuoles from other plant species showed no uptake o ...	1987	24232844
analysis of chloroplast and mitochondrial dnas in asymmetric somatic hybrids between tobacco and carrot.	chloroplast and mitochondrial dnas have been examined by comparison of restriction enzyme patterns in asymmetric hybrid plants, resulting from the fusion between leaf mesophyll protoplasts of nicotiana tabacum (solanaceae), and irradiated cell culture protoplasts of daucus carota (umbellifereae). these somatic hybrids with normal tobacco morphology were selected as a consequence of the transfer of methotrexate and 5-methyltryptophan resistance from carrot to tobacco. the restriction patterns of ...	1989	24232795
embryogenic and non-embryogenic cell lines of daucus carota cloned from meristematic cell clusters: relation with cell ploidy determined by flow cytometry.	the presence of totipotent and non-totipotent cells in embryogenic carrot cell suspension cultures was examined by cloning of cell microclusters. forty clones were isolated and the distribution of their embryogenic potential was studied. nonembryogenic, weakly and highly embryogenic cell lines were selected. after one year of subculture a second cloning round showed that the highly embryogenic and the non-embryogenic cell lines were homogenous and stable. a measurement of ploidy levels of clones ...	1990	24232682
mitochondrial genome diversity among cultivars of daucus carota (ssp. sativus) and their wild relatives.	restriction fragment patterns of mitochondrial dnas (mtdnas) from 13 carrot cultivars (daucus carota ssp. sativus), wild carrot (ssp. carota), ssp. gummifer, and d. capillifolius were compared with each other using four restriction endonucleases. the mtdnas of the 13 carrot cultivars could be classified into three distinct types - i, ii and iii - and were also clearly distinguishable from the mtdnas of wild carrot (type iv), gummifer (v) and d. capillifolius (vi). the proportions of common restr ...	1989	24232471
transfer of the cms trait in daucus carota l. by donor-recipient protoplast fusion.	x-irradiated protoplasts of daucus carota l., 28a1, carrying cytoplasmic male sterile (cms) cytoplasm and iodoacetamide-treated protoplasts of a fertile carrot cultivar, 'k5', were fused with polyethylene glycol (peg), and 73 plants were regenerated. twenty-six randomly chosen regenerated plants had non-parental mitochondrial dna (mtdna) as revealed by xbai restriction fragment patterns, and all of the plants investigated had diploid chromosome numbers. of the 11 cybrid plants that showed mtdna ...	1988	24232395
microcallus formation from maize protoplasts prepared from embryogenic callus.	conditions have been developed that induce maize (zea mays l.) protoplasts to re-synthesize cell walls and to initiate cell divisions. two types of embryogenic maize callus were used as a source of protoplasts: a heterogeneous callus (type i) derived from immature embryos after three weeks in culture, and a friable, rapidly growing callus (type ii) selected from portions of the type i callus. many variables in the growth conditions of the donor tissue (type of medium, transfer schedule, age of c ...	1986	24232151
developmental modulation of tubulin protein and mrna levels during somatic embryogenesis in cultured carrot cells.	the number of cortical microtubules (mts) increases considerably as cultured carrot (daucus carota l.) cells initiate and progress through somatic embryogenesis. the basis for this increase in mt number was investigated. a radioimmune assay was used to show that tubulin-protein per cell first decreased as the undifferentiated cells initiated embryonic development, but subsequently increased approximately fivefold between the globular and torpedo/plantlet stages. the increase during the torpedo/p ...	1987	24227436
thioredoxin and nadp-thioredoxin reductase from cultured carrot cells.	dark-grown carrot (daucus carota l.) tissue cultures were found to contain both protein components of the nadp/thioredoxin system-nadp-thioredoxin reductase and the thioredoxin characteristic of heterotrophic systems, thioredoxin h. thioredoxin h was purified to apparent homogeneity and, like typical bacterial counterparts, was a 12-kdalton (kda) acidic protein capable of activating chloroplast nadp-malate dehydrogenase (ec 1.1.1.82) more effectively than fructose-1,6-bisphosphatase (ec 3.1.3.11 ...	1987	24227431
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
secretion and membrane recycling in plant cells: novel intermediary structures visualized in ultrarapidly frozen sycamore and carrot suspension-culture cells.	freeze-fracture electron microscopy of propane-jet-frozen samples has been employed to investigate vesicle-mediated secretion and membrane recycling events in carrot (daucus carota l.) and sycamore maple (acer pseudoplatanus l.) suspension-culture cells. stabilization of the cells by means of ultrarapid freezing has enabled us to preserve the cells in a turgid state and to visualize new intermediate membrane configurations related to these events. indeed, many of the observed membrane configurat ...	1987	24227269
variation in endoplasmic-reticulum-associated glycoproteins of carrot cells cultured in vitro.	glycoproteins extracted from microsomes of in-vitro-cultured cells of daucus carota l. cv. us-harumakigosun were analysed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and detected by peroxidase-conjugated concanavalin a. the appearance of a glycoprotein with mr 31 000 (gp 31) was correlated with the ability of cells to form somatic embryos. gp 31 appeared in embryogenic cells cultured in 2,4-dichlorophenoxyacetic acid (2,4-d)-containing medium, but not in somatic embryos and non- ...	1988	24226550
ethanol production and toxicity in suspension-cultured carrot cells and embryos.	the process of carrot (daucus carota l.) somatic embryogenesis is highly sensitive to exogenously added ethanol, since 5 mm ethanol inhibits this process by 50%, whereas the growth of proliferating carrot cells is inhibited to the same extent by 20 mm ethanol. this is consistent with the fact that proliferating cultures produce ethanol and release it into the medium at concentrations up to 20 mm, whereas embryogenic culture medium contains less than 1 mm ethanol. data are presented showing the i ...	1988	24226539
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 ...	1991	24226158
purification of an autocatalytic protein-glycosylating enzyme from cell suspensions of daucus carota l.	a glycosyltransferase was identified in the 174 000 · g membrane pellet and the supernatant from extracts of cell suspensions of daucus carota l. the enzyme from the supernatant was enriched 475-fold, and sodium dodecyl sulfate-gel electrophoresis and fluorography of this purified sample showed that the only enriched protein band (40 000 da) was simultaneously an enzyme and a glucose-acceptor. gel filtration and electrophoresis under non-denaturing conditions proved that in vivo this protein pro ...	1987	24225709
purification of gp57, and auxin-regulated extracellular glycoprotein of carrots, and its immunocytochemical localization in dermal tissues.	a glycoprotein (gp57) was purified by ion-exchange and hydroxylapatite column chromatography from the 70%-ethanol precipitate of culture medium of non-embryogenic carrot cells (daucus carota l.) grown with 2,4-dichlorophen-oxyacetic acid (2,4-d). its apparent molecular mass (m r) was estimated to be 57000 by sodium dodecylsulfate-polyacrylamide gel electrophoresis and 50000 by gel filtration. gp57 contained 14% (w/w) carbohydrate; the m r of the peptide portion was estimated to be 55000 after de ...	1988	24221874
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 ...	1991	24221846
ionic basis of currents in somatic embryos of daucus carota.	a vibrating probe was used to measure extracellular electrical currents around developing somatic embryos in two lines (rcc27, rcc48) of cultured cells of daucus carota l. at the heart and torpedo stages. at ph 5.5, an inward current of 1.2±0.1 μa·cm(-2) (n=23) was detected at the cotyledon, and an outward current of 1.0±0.1 μa·cm(-2) (n=22) was found at the radicle in torpedostage embryos from the rcc27 line. at a ph of 5.75 the currents increased by 0.2-0.3 μa·cm(-2) (n=60-62). in a few cases ...	1988	24221723
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
a nuclear protein associated with cell divisions in plants.	a nuclear protein, present in carrot meristems and rapidly proliferating cultured cells of carrot (daucus carota l.) has been identified by the use of a monoclonal antibody (mab 21d7). by combining the techniques of two-dimensional polyacrylamide gel analysis and blotting separated proteins onto nitrocellulose sheets, it was shown that the antibody detected a single polypeptide of apparent molecular mass (m r) of 45000 and an isoelectric focusing point (pi) of 6.7. this protein was found by subc ...	1988	24221561
antibody localization of extensin in cell walls of carrot storage roots.	the accumulation and cross-linking of hydroxyproline-rich glycoproteins (hrgps) in cell walls of dicotyledonous plants has been correlated with a number of wall-strengthening phenomena. polyclonal antibodies raised against glycosylated extensin-1, the most abundant hrgp in carrot (daucus carota l.) cell walls, recognize this antigen on gel and dot blots and on thin sections of epoxy-embedded carrot-root cell walls. since wall labeling can be largely reduced by preincubating the antibodies with p ...	1988	24221513
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
gene-expression programs in embryogenic and non-embryogenic carrot cultures.	somatic embryogenesis can be synchronized by enriching carrot (daucus carota l.) suspension cultures for small, dense clusters of cells termed proembryogenic masses (pems). gene-expression programs of pems were compared with those of embryonic and mature tissues by in-vitro translation of representative mrna populations and by nucleic-acid hybridization. analysis of invitro-translated polypeptides by two-dimensional polyacrylamide gel electrophoresis revealed striking similarities between the mr ...	1988	24220774
acquisition of embryogenic potential in carrot cell-suspension cultures.	embryogenic suspension cultures of domesticated carrot (daucus carota l.) are characterized by the presence of proembryogenic masses (pems) from which somatic embryos develop under conditions of low cell density in the absence of phytohormones. a culture system, referred to as starting cultures, was developed that allowed analysis of the emergence of pems in newly initiated hypocotyl-derived suspension cultures. embryogenic potential, reflected by the number of fems present, slowly increased in ...	1988	24220773
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
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
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