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61.
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63.
Zusammenfassung In Nährlösung nach Bonner und Addicott (1937) wurde der Einfluß hoher Konzentrationen von Penicillin G (1,5 · 10–3 bis 6 · 10–3 g/ml) auf Aufnahme und Einbau von35S-Methionin in das Eiweiß verschiedener Entwicklungsabschnitte isolierter Wurzeln von Erbsenkeimlingen untersucht. Die Methionin-Aufnahme wurde bei den drei Wurzelsegmenten übereinstimmend durch 6 · 10–3 g Penicillin je ml Nährlösung leicht gehemmt und durch 1,5 und 3 · 10–3 g/ml gefördert, und zwar durch die schwächere Konzentration am stärksten. Die absolute Größe des Methionin-Einbaus in das Eiweiß der Wurzelzellen und die darin erreichte spezifische Methionin-Markierung werden durch das Penicillin noch weniger beeinflußt als die Stoffaufnahme. Bei Einwirkung von Penicillinmengen, die das Wurzelwachstum stark herabsetzen, weicht die Intensität des Stoffeinbaus von den unbehandelten Kontrollen (ohne Penicillin) nur unerheblich ab.
Summary In nutrient solutions (Bonner and Addicott 1937) the influence of high concentrations of penicillin G (1,5 · 10–3 up to 6 · 10–3 g/ml) was investigated upon uptake and incorporation of35S-methionine into the proteins in segments of different developmental stage of isolated roots of pea seedlings. In all three root segments uptake of methionine was slightly depressed by 6 · 10–3 g penicillin per ml nutrient solution, and stimulated by 1,5 · 10–3 and 3 · 10–3 g/ml, most strongly by the weaker concentration. The absolute quantity of methionine incorporation into proteins of root cells and the specific methionine activity reached within these cells are less influenced by penicillin than the uptake. In solutions with penicillin quantities strongly inhibiting root growth the intensity of methionine incorporation differs but insignificantly from that of tests without penicillin.
(1937) G ( 1,5 · 10–3 6 · 10–3 / 35S- . : 6 · 10–3 , 1,5 3 · 10–3 / -; . «» , , , . , , ( ).相似文献
64.
Phosphorus NMR spectra were recorded of the A horizons of a soil catena under vital stands of Liberian tropical high forest. Organic P compounds play a major part in the total P reserves (ca. 1/2 of total extractable P which is 1/5 of total soil P). Thereof, between 3.3 and 5.3 kg orthophosphate diester P per hectare participate in the plant available nutrient pool; similar amounts were calculated for the calcium acetate-lactate soluble fraction. Persistent orthophosphate monoester P makes up an even greater percentage of soil P (10 to 25 kg ha?1). Mineral fertilizer requirements are in the range of 25 to 50 kg per hectare for 10 cm depth (based on a 48 hrs. adsorption experiment) when a soil solution concentration of 0.02 mg L?1 is considered adequate for the P supply of plants. P sorption can be explained by the amorphous fractions of Al and Fe hydroxides and the percentage of clay. The apparent vitality and absence of P deficiency symptoms of forest trees suggest the existence of an intact, however delicate, natural P cycle. 相似文献
65.
Uptake of foliar applied copper and manganese by young wheat plants in the course of time Efficiency of foliar applied nutrients depends strongly on the influence of time on the rate of uptake. Rates of uptake of applied elements were determined by dipping shoots of young wheat plants into Cu or Mn sulphate solutions (0,02% Cu; 0,1% Mn) and subsequent washing off the nutrient film in intervals. Initial influx of nutrients was found to be very high, followed by a period of slow uptake after few hours. 28% Cu, but 80% Mn of the applied amounts were absorbed during the 7-day study. 11% of the absorbed Cu and 14% of the Mn were transferred from shoots to roots within two weeks. 相似文献
66.
Wolfgang Thomas 《Water, air, and soil pollution》1984,22(4):351-371
Concentrations of PAH (1.12-benzoperylene, 3.4-benzopyrene, fluoranthene), chlorinated hydrocarbons (α-BHC, lindane, PCB) and trace metals (Zn, Pb, Cu) in bulk precipitation, as well as PAH and trace metal concentrations in atmospheric dust samples from 14 sites in Bavaria, F.R.G. are presented for two vegetation periods (1979 and 1980). The same substances were also analyzed in epiphytic moss (Hypnum cupressiforme var. filiforme) sampled from tree trunks in October 1979 and 1980. Using mean immission values and the amount of precipitation as predictors and concentrations of pollutants in moss samples as criteria, a number of multiple regression models were computed in order to quantify the relationships between absolute air pollution data and accumulated trace substance values. Beta values of all variables help to determine whether bulk precipitation or atmospheric particulate matter has dominant influence on the uptake of trace substances by mosses. The study shows that epiphytic mosses can be used to monitor both heavy-metal, PAH and chlorinated hydrocarbons. 相似文献
67.
Kristina Bachteler Monika Riedel Nikolaus Merkt Wolfgang Schies Jutta Fröhlin Jens Wünsche 《Journal of plant nutrition》2015,38(6):839-853
Berry shrivel and bunch stem necrosis are the economically most important physiological disorders of grapevine. The nutritional status of the plant is considered as one of the main elicitors for the occurrence of these disorders. For foliar fertilization trials, two vineyards that had previously been affected by both diseases were selected in Southwest Germany, one with the variety ‘Zweigelt’ and one with Pinot Blanc. By the use of potassium, magnesium, and calcium foliar fertilizers, a rapid increase of different nutrients in the plants should be caused and the effects on the diseases observed. In 2010, no significant differences in the fertilization treatments were found for both varieties. In ‘Pinot Blanc’, significantly more berries were affected by berry shrivel in 2011 in plots treated with calcium fertilizer compared to those treated with potassium and magnesium. Plots with magnesium fertilizer showed significantly less berries affected by berry shrivel than the untreated control. 相似文献
68.
Sulfur fractions in forest soils of the SO2-polluted Fichtelgebirge The sulfur status of a soil sequence (two Dystric Cambisols, Haplic Podzol, Eutric Cambisol) in SO2-polluted coniferous and hardwood forests of the Fichtelgebirge (North-East Bavaria) is investigated. In the mineral soil layers St fluctuates between 37 to 943 ppm; 11–84% of St is Sp. Layers rich in clay contain up to 79%-SE, whereas in sandy to silty substrates organic bound C?S-S dominates. The organic surface layers show 1.0–2.9‰ St, maximum in the Oh. 69–90% of St are C?S-S. Sp is low with a maximum in the L-horizons (9–19% of St). SE is vice versa, because values increase from L (0–8% of St) to Oh (7–22% of St). The characterization of the sulfur status in a forest ecosystem by investigation of organic layers presumably is more reliable than the results of needle and mineral soil analyses. 相似文献
69.
Formation of Humic Substances during Composting Wheat Straw During composting straw (with and without N-addition) in a model-compostreactor with continuous progress of rotting it comes to an increase of the fraction of humic acids under simultaneousness decrease of their prestages. The synthesis of humic acids is strongly marked in the thermophilic area. Compared with the untreated variant up to 30% more of the humic acids are formed in the N-treated plots. After the maximum temperature the formation of humic acids break down. A direct relation exists between the microbiological decomposition of the organic matter and the formation of humic acids. IR-spectroscopic measurements show no qualitative differences either between or within the compost variants. 相似文献
70.
The photochemical reactions of phosmet, an organophosphorus insecticide used for plant protection and for control of ectoparasites on productive livestock, were studied in the presence of wool wax. Induced by UV light, phosmet features numerous degradation pathways as well as photoaddition reactions with lipid structure moieties. In model irradiation experiments of phosmet in mixtures of solvents (cyclohexane, cyclohexene, 2-propanol) and fatty acid methyl esters (methyl stearate, methyl oleate, 12-hydroxymethyl stearate), both adjusted to the hydroxyl and iodine values of wool wax, half-lives were determined to be approximately 7 and 16 h, respectively. Irradiation of phosmet on crude sheep wool resulted in a degradation rate of 65% after 24 h. In tracer studies with stable isotope labeled phosmet ([15N]phosmet) in commercial lanolin and on raw sheep wool, employing a sunlight simulator and natural sunlight, wool wax bound phosmet was formed. After extraction and measurement by elemental analyzer/isotope ratio mass spectrometry, delta15N values of the phosmet-free wool wax fractions were notably increased as compared to the value of natural lanolin. Calculated from the delta15N values, an average of 13.9/15.6% (sunlight simulator/natural sunlight) was bound to wool wax lipids after irradiation of thin films of commercial lanolin. In experiments with sheep wool, 13.2 and 15.4%, respectively, were detected as wax-bound. 相似文献