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171.
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173.
Agents known to influence Ca2+ homeostasis affected significantly the vegetative growth and starvation-induced conidiation ofTrichoderma viride. Ca2+ in millimolar concentrations stimulated both growth and conidiation; a Ca2+ deprivation of the fungus by the chelation of extracellular Ca2+ (not Mg2+ or divalent trace metals) with EGTA (ethyleneglycolbis(2-aminoethylether)-N,N,N′,N′-tetraacetic acid) restricted both the
vegetative growth rate and starvation-induced conidiation. Both processes were affected by either Ca2+ or EGTA with different efficiencies. Divalent cations (Sr2+, Ba2+, Co2+, Ni2+, Mg2+, Cd2+, Cu2+, Mn2+) and La3+ (inorganic Ca2+ blockers) in millimolar concentrations exerted complex (stimulatory, inhibitory, or biphasic) effects on growth and conidiation.
In general, their effects on the two processes were mutually different either qualitatively, or quantitatively, or both. Organic
Ca2+ antagonists (verapamil and dihydropyridines) inhibited the vegetative growth. The results show that Ca2+ is required for vegetative growth and conidiation, and that different Ca2+-dependent mechanisms may be involved in the two processes. Divalent cations could serve as a tool for investigating the relationship
between growth and conidiation. 相似文献
174.
A. S. Buchalo V. Šašek V. P. Kaczurovskaya A. F. Griganski N. Yu. Mitropolskaya O. A. Zakordonec 《Folia microbiologica》1996,41(2):187-192
Using scanning electron microscopy it was possible to describe structures on the mycelia of macromycetous fungi that possess both taxonomic and functional importance. For taxonomic characteristization of 11 studied species, the presence and distribution of clamps on hyphæ represent an, important feature; in the case ofLyophyllum decastes the form of clamps may be useful for identifying cultures. Formation and types of anamorhps inPleurotus calyptratus, Montagnea arenaria andLyophyllum decastes are also of taxonomic importance. For additional taxonomic characterization of cultures ofTricholoma mongolicum the formation of “coils” might be exploited. Formation of anastomoses and crystals has predominantly a physiological role. However, in our view, production of crystals under certain culture conditions may serve as a diagnostic parameter. 相似文献
175.
Vanadate (NaVO3) in concentrations between 0.1–3.0 mmol/L inhibited the production of secondary metabolites (SMs) of strains of the following
species:Trichoderma viride, Penicillium purpurogenum, Penicillium citrinum, Talaromyces avellaneus, andVerticillium psalliotœ. Growth was either not affected by NaVO3, or the inhibition of the SM production occurred at lower NaVO3, concentrations than that of the growth. Thus, at some NaVO3 concentration the SM production was inhibited but the growth remained unaffected. The results suggest that NaVO3 exerts a specific action either on the SM biosynthetic pathway(s) or on the export of SMs from cells. 相似文献
176.
177.
The mutagenic activity of more than 120 antimicrobial agents and protective components was investigated. Only Kathon showed
a consistent increase in revertant counts in the Ames test onSalmonella typhimurium. The hereditary bleaching test onEuglena gracilis used for detecting extranuclear mutations, showed positive results for Kathon, triethanolamine and diamine silver tetraborate. 相似文献
178.
A methodology is proposed for assessing the ecological value of streams in the catchment of the Moravská Dyje River. It is concluded that by using a wide range of parameters that a more objective assessment is achieved than if only one were used. The landscape of the catchment studied contains excessive amounts of nutrients and, in comparison to its natural state, has become too uniform. 相似文献
179.
R. Socha J. Šula 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1996,166(6):382-387
Three different cultures of dimorphic bug,Pyrrhocoris apterus, were analyzed concerning diapause and its relation to wing morph pattern. The proportion of macropterous bugs was considerably
higher (36%) in the Mediterranean culture from Israel than that (1.3%) in the temperate culture from the Czech Republic. The
macropterous morph- and brachypterous morphrelated types of reproduction arrest, differing by the length of pre-oviposition
period, were distinguished in cultures analyzed. The reproduction arrest with an average pre-oviposition period of 38.2 days
in Mediterranean macropters and 18.5 days in macropters from selected macropterous strain, was found to be typical for macropterous
morph. Two different photoperiodic conditions induced macropterous morph-related reproduction arrest, the long-day (18 h light-6
h dark) photoperiod in macropterous strain macropters and the short-day (12 h light-12 h dark) photoperiod in Mediterranean
macropters. The brachypterous morph-related reproduction arrest, characterized by pre-oviposition period longer than 90 days,
occurred predominantly in diapausing brachypterous bugs. While the hibernal diapause of brachypterous bugs was characterized
by a very high level of the 78- and 82-kDa proteins in haemolymph, their content in haemolymph of macropters during macropterous
morph-related reproduction arrest was almost as low as in the reproductive adults. The variation of reproduction arrest in
relation to wing dimorphism represents an important feature in the life strategy ofP. apterus. 相似文献
180.
Miodrag Petrović Ilijana Grigorov Tanja Milosavljević Desanka Bogojević Snežana Ŝekularac Ljiljana Ševaljević 《Molecular biology reports》1996,23(2):79-85
A 29 kD soluble rat liver nucleoprotein (p29) has increased binding affinity for the hormone responsive element (RE) of the rat haptoglobin (Hp) gene during the acute-phase reaction. In this work the possibility of its structural and functional homology to the high mobility group 1 (HMG1) nonhistone protein constituent of chromatin was examined. The results of two-dimensional gel electrophoresis, Southwestern and Western immunoblot analyses, showed that p29 and HMG1 are homologous protein species. On the basis of in vitro and in vivo phosphorylation/dephosphorylation experiments, we discuss the modulatory role of phosphate groups in view of the structure and function of p29. 相似文献