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101.
Ferredoxins were isolated from the freshwater red alga Porphyridium aerugineut, and from Porphyridium cruentum, a related marine species. A sin 相似文献
102.
In petals of Silene dioica, gene P controls the 3′-hydroxylation of the anthocyanin B-ring and the hydroxylation pattern of the hydroxycinnamoyl acyl group bound to the 4″'-hydroxyl group of rhamnose of anthocyanidin 3-rhamnosyl(1→6)glucoside-5-glucoside. In this paper, experiments are presented which show that gene P is involved in the hydroxylation of p-coumaroyl-CoA to caffeoyl-CoA, which is then used both as a precursor in anthocyanin biosynthesis and as a substrate for the final acylation. 相似文献
103.
Abstract. A brief high temperature treatment (45 C) promoted anthocyanin synthesis in 2-d-old dark-grown red cabbage seedlings. The increased effectiveness of a temperature/red light treatment as opposed to the reverse sequence suggests that an elevated temperature 'induces' some component which facilitates the phytochrome response. 相似文献
104.
In the wing disks of Drosophila slowly dividing cells of Minute mutations are progressively eliminated from Minute/Minute+ mosaic compartments by a process known as cell competition. From a study of two different Minutes we show here that the intensity of competition is greater in the more extreme Minute with the slowest rate of cell division. The way in which the more rapidly growing Minute+ clones grow and overcome the surrounding Minute cells is described and cell competition is shown to be a result of local interactions between slow- and faster-growing cells. 相似文献
105.
J Michelot B Dastugue N Defer G Meyniel 《Biochemical and biophysical research communications》1979,88(4):1368-1374
In vitro incubations of cytosol proteins from human red blood cells with [125I] labelled L-3,5,3′ triiodothyronine demonstrated the existence of high affinity and limited capacity binding sites for T3. At 4°C, the rate constant of association was 3 × 107 M?1h?1, and the rate constant of dissociation was 9.10?3h?1. The dissociation constant Kd was calculated from these data or measured by Scatchard analysis and found to be between 3 and 7.10?10M. The maximum binding capacity was 1.4 f moles of L-3,5,3′ triiodothyronine per mg cytosol proteins. A close parallel between the biological pontency of the analogs of L-T3 was observed. 相似文献
106.
Kazuaki Goriki Richard E. Tashian Sharon K. Stroup Ya-Shiou L. Yu Dag M. Henriksson 《Biochemical genetics》1979,17(5-6):449-460
A new inherited variant of carbonic anhydrase I (CA I), designated CA INagasaki 1 (CA INGS 1), was discovered during a survey of hemolysates from 5852 individuals from the cities of Hiroshima and Nagasaki in Japan. Analysis of the amino acid composition of a tryptic peptide from the CA INGS 1 variant indicated that a glutaminyl residue was substituted for an arginyl residue at position 76. Heat degradation studies showed that the CA INGS 1 variant was less stable than normal CA I. The CO2 hydrase and esterase activities of the normal and variant carbonic anhydrases I, as well as the relative amounts of the two enzymes in heterozygotes, were similar.This work was supported in part by Contract E(11-1)-1552 with the Energy Research and Development Administration, Washington, D.C. (to J. V. Neel), and by U.S. Public Health Service Grant GM-24681. 相似文献
107.
A new species of the dinoflagellate genus Cachonina, C. illdefina sp. nov., was isolated from a red tide off El Capitan State Park, Santa Barbara County, California, in October 1973. The organism is light yellowgreen in color with deeply incised girdle and sulcal grooves. Electron microscopy of the organism, revealed a typical dinokaryotic nucleus. The chloroplasts of the organism are connected, and often contain microtubule-like elements, 25 nm diam. The pyrenoids are characterized as excluding chloroplast thylakoids and ribosomes, although containing an amorphous matrix and numerous tubular invaginations from the cytoplasm. The pyrenoids become detached from the chloroplasts and degenerate into small vesicles. C. illdefina is not bioluminescent. 相似文献
108.
The promotion of anthocyanin synthesis in red-cabbage seedlings by 5 min exposure to R light is inhibited by subsequent application of CaCl2. The stimulation of dark synthesis of anthocyanin by n-PrOH and by kinetin is also reduced by Ca2+ and by cholesterol, both of which are well known to stabilize cell membranes. By contrast, EDTA, which chelates Ca2+, promotes dark synthesis of anthocyanin. Assay of native Ca2+ extractable from seedlings immersed in EDTA demonstrates that R light exposure promotes a highly significant increase in extractable Ca2+. It is suggested that the molecular configuration of the phytochrome molecule affects the ability of a membrane to bind Ca2+ and that this in turn affects the permeability to substrates which are required for anthocyanin biosynthesis. 相似文献
109.
C. M. Karssen 《Physiologia plantarum》1982,54(3):258-266
During temporary incubation at 25°C in buffered solutions (pH 4.0) of abscisic acid (ABA) seeds of lettuce ( Lactuca sativa L. cv. Olof) lost the red-light initiated ability to germinate in buffer. The development of secondary dormancy required an inhibitory ABA content in the seeds during a number of days. A temporary incubation in ABA during 24 h met these requirements only if the solution was about 100-fold more concentrated than during continuous incubation. Studies with 2-14 C-ABA showed that the amount of ABA which had penetrated in 24 h was reduced by a factor 100 within 3 to 4 days during subsequent incubation in buffer. Both leaching and metabolic changes were involved in the reduction process. The nature of the metabolic products remained obscure. A shift to 2°C after incubation in ABA prevented the induction of secondary dormancy, but inhibited ABA metabolism. ABA did not interfere with the induction rate of secondary dormancy, and it was not required to maintain the state of dormancy. The sole function of ABA was the non-specific inhibition of germination, which indirectly facilitated the development of an ABA independent secondary dormancy. – The level of endogenous ABA was compared to the amount of ABA found in the embryo during and after incubation in ABA solutions marked with 2-14 C-ABA. The level of endogenous ABA in air-dry seeds (0.11 ng/mg dry weight) corresponded to the minimal level at which penetrated ABA inhibited germination. This level had to be present at least during 4 to 5 days to inhibit the effect of red light. Since endogenous ABA was quickly reduced upon imbibition, a regulatory function of endogenous ABA in the inhibition of red light induced germination can be ruled out. A function in the temporary inhibition of dark germination and, consequently, in the development of secondary light irresponsiveness cannot be excluded, however. 相似文献
110.
《Bioscience, biotechnology, and biochemistry》2013,77(3):704-710
Recent studies indicate that some raphidophycean red tide flagellates produce substances able to scavenge superoxide, whereas there have been no reports on superoxide scavenger production by dinophycean red tide flagellates. In this study, we examined the superoxide-scavenging activity of aqueous extracts from dinophycean red tide flagellates, Gymnodinium spp., Scrippsiella trochoidea, and Karenia sp., by a luminol analog L-012-dependent chemiluminescence (CL) method and an electron spin resonance (ESR)-spin trapping method, and compared the activity to that of raphidophycean red tide flagellates, Chattonella spp., Heterosigma akashiwo, and Fibrocapsa japonica. In the experiment applying the L-012-dependent CL method, only the aqueous extracts from raphidophycean red tide flagellates showed superoxide-scavenging activity. On the other hand, applying the ESR-spin trapping method, we found that the aqueous extracts from dinophycean red tide flagellates also showed superoxide-scavenging activity. This is the first report on the production of a superoxide-scavenger by dinophycean red tide flagellates. 相似文献