Invertase in cultured Daucus carota cells

Invertase activity of cultured carrot cells was distributed between cell wall and supernatant fractions of the cell homogenate. The enzyme associated with the cell wall fraction was solubilized by alkaline NaCl solution and the proportions found in the cell wall and soluble fractions depended on the concentration of NaCl. Formation of protoplasts by the action of cellulase and pectinase was accompanied by release of 50–60% of the invertase activity from the cells.     

Lipids of Daucus carota cell suspension cultures

In carrot cell suspension cultures greater amounts of phospholipid were detected than in carrot root material, but the major phospholipid classes were the same in both materials, and their fatty acid composition was very similar. In contrast to the cultured cells, no significant amounts of free fatty acids and monoglycerides, as well as diglycerides, could be detected in the carrot root. The fatty acid composition of the major lipid classes from cell cultures is reported for the first time in this report. The degree of unsaturation was higher in triglycerides and phospholipids than in free fatty acids. In a study of phospholipid biosynthesis, [³H]-glycerol was shown to be incorporated into 4-phospholipids (PE, PC, PG, PS⁷) to different extents. The highest specific activity was observed in PC and PG. Five molecular species were isolated from each of the 4 phospholipids and analyzed by GC-MS and LSC.     

Lipid composition of Daucus carota roots

Lipids extracted from Daucus carota roots were analyzed and the fatty acid composition of the triglycerides and phospholipids determined. Compariso     

Differentiation of metabolic pathways in the umbel of Daucus carota

The extractable activities of PAL, chalcone synthase and chalcone isomerase of white and coloured petals of the inflorescence of the umbel of wild carr     

Changes in chromatin of Daucus carota cells during embryogenesis

Cells of carrot (Daucus carota var. Rote Riesen) were cultured on media inductive and non-inductive for embryogenesis and analyzed for differences in their chromosomal proteins and chromatin template activity. Non-histone proteins were prepared from dehistonized chromatin and their properties were investigated. Non-histone proteins proved to be acidic and associated easily with calf thymus histone. Non-histone proteins were able to counteract the inhibitory effect of histone on DNA-directed RNA synthesis in vitro. Almost the same rate of restoration occurred regardless of the interaction between DNA and protein, when sufficient amounts of non-histone proteins were added. However, once the histone-DNA complex was established, the restoration by non-histone proteins at comparably lower concentration was poor. Another acidic protein, bovine serum albumin, had no effect on histone inhibited RNA synthesis. Also non-histone proteins enhanced the chromatin directed RNA synthesis more than 100%. The template activity of chromatin changed after the inductive treatment of embryo formation and induced cells showed higher template activity than non-indiiced controls after embryo cells were formed. Histone components were the same in inductive and non-inductive cells. On the other hand, there was a correlation between template activity and the stimulation by non-histone proteins of histone-inhibited RNA synthesis.     

A Unique pattern of anthocyanins in Daucus carota and other umbelliferae

Three cyanidin glycosides have been identified in the black carrot: the known 3-lathyroside and two new pigments, a 3-xylosylglucosylgalactoside and its ferulyl derivative. The same pigments, together with the sinapyl derivative of the triglycoside, occur variously in other tissues of Daucus carota. Ferulyl and sinapyl derivatives of cyanidin 3-glucosylgalactoside occur exceptionally in stem of one subspecies, maritimus. One or other of the same pigments have been found to occur variously in 20 of 22 other umbellifer species surveyed. Both ferulyl and sinapyl derivatives occur in stem of Conium maculatum and Foeniculum vulgare. A further novel acylated pigment based on p-coumaric acid was found in wild celery, Apiurn graveolens. The systematic significance of these various findings is discussed.     

Phytochelatins govern zinc/copper homeostasis and cadmium detoxification in Cuscuta campestris parasitizing Daucus carota

Cuscuta sp., known with the common name of “dodder”, is an obligate parasite capable of invading stems and leaves of a wide range of host plants. Dodder stem usually coils counterclockwise around the host and, within a few days, develops haustorial structures at each point of contact. As soon as dodder haustoria reach host vascular bundles, they start tapping water, photosynthates and minerals. Metal ions such as zinc (Zn) and copper (Cu) are essential for dodder growth and metabolism, although an exceedingly high (over-homeostatic) supply of these micronutrients can result in growth inhibition and cellular toxicity. Even more so, non-essential metals such as cadmium (Cd), if transferred from the host to the parasite, need to be neutralized by timely detoxification mechanisms. In this work, we showed that Cuscuta campestris Yuncker establishes effective haustorial connections with leaf petioles and blades of Daucus carota L. (carrot), with the consequent transfer of Cd and essential metals (such as Zn and Cu) from the host vascular bundles to the parasite. Following up to this point, we detected the presence in the parasite of significant amounts of glutathione and phytochelatins, even in the absence of Cd exposure. This suggests that thiol peptides in dodder might be particularly important for Zn and Cu homeostasis as well as for Cd detoxification. Finally, we demonstrated that dodder is capable of synthesizing phytochelatins on its own, rather than massively importing them from the host, and also provided evidence for the existence of an endogenous, constitutively expressed, dodder's phytochelatin synthase.     

Abnormal metabolites produced by Daucus carota roots stored under conditions of stress

The formation of dihydroisocoumarins (I and II), the chromones (III and IV) and scopoletin (V) is induced in carrot roots by storage in the presence of low concentrations of ethylene and by inoculation with various fungi. There has been concern over possible toxic effects of dihydroisocoumarins and some preliminary toxicological data on (I), (II) and (IV) are included.     

Location and density labelling of acid invertase in aging discs of Daucus carota storage tissue

Cell walls prepared from aged discs by extraction in 0·1 M acetate buffer, pH 4·8, possess ionically bound acid invertase which can be removed from the wall by incubation in 1 M sodium chloride in 0·1 M acetate buffer, pH 4·8, and more firmly attached enzyme which is not removed. Cell walls prepared in 0·195 M phosphate-0·003 M citrate-buffer, pH 8·0, do not possess ionically bound enzyme. Ionically bound invertase is density labelled when discs are aged in 90% deuterium oxide suggesting that at least part of the increase in activity observed during aging is due to de novo protein synthesis.     

Genetic variation for volatile terpenoids in roots of carrot, Daucus carota, backcrosses and F2 generations

Volatile terpenoid levels were measured in segregating carrot populations. Genetic analysis suggested dominance and multigenic control for low total volatile terpenoids, and low terpinolene quantities. The inheritance of caryophyllene quantities differed in different populations. Percent (E)-γ-bisabolene exhibited simple genetic control in several carrot populations with dominance for high levels. Compensatory shifts between the major volatile terpenes indicates an inter-relationship between the mono- and sesquiterpenoid biosynthetic pools.     

Genetic variation for volatile terpenoids in roots of carrot, Daucus carota, inbreds and F1 hybrids

Volatile terpenoid levels were determined in eight carrot inbreds and ten F₁ hybrids. Genetic variation between inbreds spanned a 5-10-fold range f     

5'-Nucleotidases: specific assays for five different enzymes in cell extracts

Several mammalian 5'-nucleotidases (5-NTs), attached to membranes or present in the cytosol or in mitochondria, remove the phosphate from ribo- and deoxyribonucleotides with different specificities for the sugar and base moieties. Some enzymes probably participate in signaling functions by producing adenosine from AMP. A more general function may be to prevent overproduction of deoxyribonucleotides. 5-NTs may affect the pharmacological activity of nucleoside analogs and also be involved in their mitochondrial toxicity. Here we describe for five cloned 5-NT specific assays that largely rely on new inhibitors for some of the enzymes. The assays can be used to quantitate each enzyme in crude cell extracts. To ascertain their validity we applied each assay to extracts from genetically modified cells that overproduce separately each of the five enzymes. The methodology should be useful in further studies of the physiological function of 5-NTs and their influence on the clinical use of nucleoside analogs.     

Biotransformation of tetrahydroberberine to berberine by enzymes prepared from cultured coptis japonica cells

Crude enzymes were extracted from cultured Coptis japonica cells producing large amounts of berberine. One of the enantiomers of tetrahydroberberine, (S)-(?)-tetrahydroberberine, was dehydrogenated to berberine by the enzyme system.     

Starch gel electrophoresis of certain enzymes from five species of Fomes

The electrophoretic banding patterns of five enzymes (esterase, catechol oxidase, peroxidase, alkaline phosphatase, and acid phosphatase) from eleven isolates of five species of the wood-rotting basidiomycete, Fomes, were subjected to mathematical analysis in order to examine taxonomic relationships. Generally, greater similarity was observed between the banding patterns for isolates of the same species than between those for isolates of different species. The experimental and analytical technique used in this study could be an aid for the determination of taxonomic relationships among these and other fungi.     

RNA extracts of lymphoid cells sensitized to DNP-oligolysines convert nonresponder lymphoid cells to responder cells which release migration inhibition factor

Strain 13 nonresponder peritoneal exudate cells were converted to responder status to α or ?,DNP-oligolysines after incubation of the cells with RNA extracts prepared from responder guinea pigs skin test sensitive to these synthetic antigens. The conversion of nonresponder strain 13 cells was assessed by the direct cell migration inhibition correlate of delayed hypersensitivity. Nonresponder cells were not converted by RNA extracts prepared from unimmunized responder guinea pigs or from non-responder strain 13 guinea pigs previously injected with DNP-oligolysines. Thus, it seems possible to correct immunological unresponsiveness in vitro in spite of a specific genetically determined deficiency of the immune response related to the Ir gene.     

The accumulation of five fluorescent compounds in the cotton leaf induced by cell-free extracts of Aspergillus flavus

(?)-Cryptocaryalactone (6-[2-acetoxy-4-phenyl-3-butenyl]-5,6-dihydro-2-pyranone) and (?)-deacetylcryptocaryalactone (6-[2-hydroxy-4-phenyl-3-butenyl]-5,6-dihydro-2-pyranone) isolated from Cryptocarya moschata seeds are natural germination inhibitors. Applied at 0.004 M, the second compound completely arrested germination of velvetleaf (Abutilon theophrasti) and decreased the germination rate of soybeans, but did not appear to affect corn. The first compound was not as effective; 0.004 M reduced velvetleaf germination 50%.