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71.
72.
Antti Huunan-Seppälä 《Journal of bioenergetics and biomembranes》1971,2(3-4):197-207
The effect of the polybasic substances Polybrene and spermine on the passive and active transport of monovalent cations in mitochondria was studied. These agents were found to stimulate the low amplitude swelling of mitochondria. Volume oscillations were induced by addition of substrate in the presence of spermine. In conditions where weak oscillations were obtained without these substances, oscillations were stimulated and their frequencies increased in the presence of Polybrene and spermine. Their effects were maximal with 100–300 moles spermine per litre and 3–5 mg Polybrene per litre. These results are discussed in relation to an interaction of the agents studied with membrane negative charges which may be important regulators of ion transport. 相似文献
73.
Incompatibility in Podospora anserina: Comparative Properties of the Antagonistic Cytoplasmic Factors of a Nonallelic System 下载免费PDF全文
In the fungus Podospora anserina, the interaction between the nonallelic incompatible R and V genes has two consequences: a lytic reaction due to the synthesis of specific proteolytic enzymes, and a quenching in protein and ribonucleic acid synthesis. The incompatibility reaction when vegetative or sexual R and V cells fuse is asymmetric: it is induced only in the R protoplasm. The cessation in ribonucleic acid and protein synthesis was investigated in heterokaryotic strains carrying the antagonistic R and V genes and their "neutral" r and v alleles. Asymmetry between R and V genes lies in the fact that the strains homozygous for the R genes are the only strains that cannot grow. From these results it is postulated that the V-gene product is a diffusible cytoplasmic factor and that the R-gene product, which is nonautonomous, is a ribosomal component. 相似文献
74.
75.
The virus origin of a Czechoslovak isolate of potato witches' broom disease is discounted: electron micrographs of ultrathin section of phloem tissues from plants infected with potato witches' broom disease demonstratedMycoplasma-like bodies, spherical or elongated showing binary fission and fragmentation. The minute corpuscles have a diameter of about 50–60 nm, the largest bodies of 1000 nm. The width of elongated filamentous structures is about 200 nm, most oval bodies have a diameter of 250 nm. A weak tetracycline treatment of diseased plants causes a delay of symptom development; a strong dose of tetracycline (applied by means of the wick method into the stem) inhibits symptom appearance completely. Tetracycline produces a phytotoxic effect inhibiting the growth of tomato plants and causing (at higher concentrations) necrosis and death of these plants. There is a note in the paper dealing with the term “mycoplasma”. The word mycoplasma in the sense ofEriksson (1897) or ofMereschkowsky (1910) does not correspond to the genus nameMycoplasma Nowak (1929). 相似文献
76.
Henri Saëz 《Mycopathologia》1970,41(3-4):383-395
Résumé Chez 44 Babouins,Papio papio (Desm.), appartenant à la collection du Parc zoologique de Paris, distingués en trois groupes, en fonction de l'âge, nous avons pratiqué 101 prélèvements aux niveaux suivants du tube digestif: intestin grêle gros intestin et rectum.C'est chez les animaux les plus âgés que nous avons obtenu les valeurs les plus élevées pour les deux critères étudiés, le pourcentage de positivité et la richesse spécifique des prélèvements et ce, aussi bien en ce qui concerne l'ensemble des levures identifiées que pour les seuls constituants de la flore probable. La fréquence de ces champignons aux divers étages du tube digestif, ainsi que l'incidence saisonnière sur les isolements ont été abordés.
In 44 Baboons,Papio papio (Desm.), of the Zoological Park of Paris, 101 samples have been taken at three levels of the alimentary tract: small intestine, large intestine and rectum. Three groups of subjects have been recognized according to age. The yeasts or the yeast-like flora, have been found with maximum of frequency and diversity in the oldest animals. The variations of the isolation in the three levels of this Mammal's gut and the seasonal influence have been discussed.相似文献
77.
The course of biosynthesis of fatty acids in the seeds of winter rape (Brassica napus L. ssp.oleifera, f.biennis cv. T?ebí?ská) was investigated. After the termination of flowering seed samples were taken at five intervals, the seeds were divided into 4 fractions according to size, and their weight, water content, oil content and fatty acid composition were determined. The oil content was found to increase in all size categories with time, with the exception of a minute drop when complete maturity is reached. Larger seeds contained more oil. The fatty acid composition changes with time in the individual size fractions almost continuously. The same holds for differences between seed sizes of the same sample. The main change in oil composition consists in the decrease of C18 acids in favour of C22 acids. Greatest decrements during maturation were found with oleic acid, less with linoleic acid. In absolute amounts the quantity of all synthesized acids rises, the greatest rise being observed with C22 acids (i.e. predominantly erucic acid). It follows from the mean rates of synthesis of the individual groups (C16, C18, C20, C22) of fatty acids that the fraction of C22 rate of synthesis increases, while that of the C18 acids decreases with the same speed. The results indicate that the fatty acid synthesis is most intense during the second half of seed maturation, the main role being played by accelerating the synthesis of higher acids, especially of erucic acid. 相似文献
78.
Ribosomal precursor RNA in Saccharomyces carlsbergensis 总被引:9,自引:0,他引:9
79.
Lubomír Scháněl 《Biologia Plantarum》1966,8(4):292-298
Mycelium of white-rot fungi secretes laccase into the medium. It was found by cultivation on malt-agar plates that the mycelium does not produce laccase equally in all its parts. The youngest hyphae at the margins of the colony represent usually the maximum producers, whereas older hyphae produce less or none at all. An exception here isCollybia velutipes which is the weakest producer of laccase of all the fungi studied and where only the older hyphae begin to secrete it. Manometric estimation of laccase showed that maximum specific activity of laccase is achieved at the boundary between the phases of initial and linear growth and i11 some cases during the first half of linear growth. Ageing of the mycelium characterized by certain changes in its metabolism is reflected in changes of enzyme production by fungal hypha of different age. 相似文献
80.