13 תוצאות
Mitochondria isolated from maize plants with S-type male-sterile cytoplasms are capable of synthesizing four species of RNA at concentrations of actinomycin D that eliminate all DNA-directed RNA synthesis. No RNA synthesis occurs under the same conditions with mitochondria from plants possessing
In this study, changes in DNA transcription activity are presented during parenchymal cell differentiation of the primary cortex of roots of a species with elevated DNA content in which endomitotic polyploidization does not occur (Tulipa kaufmanniana), as well as a species with low content levels in
Five-or six-day old seedlings of corn (Zea mays L.) were exposed to 0.25 mm Ca(NO(3))(2), 1.0 mm sodium 2-[N-morpholino]-ethanesulfonate, 5 mug Mo per liter and 50 mug of chloramphenicol per ml at pH 6. Nitrate uptake was determined from depletion of the ambient solution. The pattern of nitrate
The impact of fish oil on tumour necrosis-alpha (TNF-alpha) production by macrophages stimulated by lipopolysaccharide (LPS) was examined in mice. Animals were fed high fat diets (20% fat wt/wt) rich in fish oil, corn oil or coconut oil for 4 weeks; a group of mice fed a low fat diet (5%) was
The sensitivity of the 3-methylcholanthrene (MC)-mediated induction of aryl hydrocarbon hydroxylase (AHH) activity to pretreatment with inhibitors of protein and RNA synthesis was studied. Cordycepin significantly inhibited the induction at 12 h but not at 3 h post-treatment with MC. Both
The evidence presented in this paper suggests that purified plant chromatin, similar to mammalian (SR Umansky et al., Eur J Biochem 1980 105: 117-129), has the ability to incorporate amino acids into acid precipitable material. The polypeptide-synthesizing system of chromatin seems to differ
The lifetime of the zein mRNA in a developing corn (Zea mays L.) kernel under genome transcription blockade with actinomycin D (in vivo) and in a cell-free system (in vitro) was studied. After a 10 h blockade of gene transcription with actinomycin D, only 55% of 19 kDa zein mRNA and 40% of 22 kDa
Oil feeding is known to increase the secretion of intestinal alkaline phosphatase (IAP) into serum and this phenomenon is shown to be mediated by surfactant-like particles. These lipoprotein particles are secreted by enterocytes and are rich in phosphatidyl choline and IAP. The exact mechanisms
The stimulation of ethylene production from seedling tissue of Phascolus vulgaris, Helianthus annuus and Zea mays by growth regulators was inhibited by actinomycin D and puromycin and to a lesser extent by 2-thiouracil and p-fluorophenylalanine. It is concluded that the mechanism of action of growth
Dietary supplementation with fish oil has previously been shown to enhance in vivo and in vitro (macrophage) synthesis of tumor necrosis factor-alpha (TNF-alpha) in response to bacterial lipopolysaccharide (LPS) stimulation. The studies reported here were conducted to gain insight into the molecular
The pattern of change in the activity of alcohol dehydrogenase in maize (Zea mays L.) scutellum during seed germination is not altered by 10 mug/ml cycloheximide or 50 mug/ml actinomycin D. The enzyme does not become density labeled when maize seeds are germinated in the presence of D(2)O and
The effect of light on protein synthesis during the early stages of greening of etiolated maize (Zea mays) leaves was studied using double labeling with leucine and fractionation of proteins by gel filtration and acrylamide gel electrophoresis. The incorporation of labeled leucine into a relatively
The development of amylase activity in extracts from de-embryonated and GA(3)-treated de-embryonated maize kernels (Zea mays L.) was determined during a 10-day incubation period. The increase in activity was compared with activity extracted from endosperms dissected from germinating whole kernels.