Einfluß von Penicillin in hoher Konzentration auf Aufnahme und Einbau von35S-Methionin in isolierte Wurzeln vonPisum sativum

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.

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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.

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(1937) G ( 1,5 · 10^–3 6 · 10^–3 / ³⁵S- . : 6 · 10^–3 , 1,5 3 · 10^–3 / -; . «» , , , . , , ( ).

     

Phosphorus Status of a Soil Catena under Liberian Evergreen Rain Forest: Results of 31P NMR Spectroscopy and Phosphorus Adsorption Experiments

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.     

Der zeitliche Verlauf der Aufnahme von Kupfer und Mangan durch den Sproß junger Weizenpflanzen

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.     

Statistical models for the accumulation of PAH,chlorinated hydrocarbons and trace metals in epiphytic Hypnum cupressiforme

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.     

Effects of Foliar Fertilization on Incidence of Berry Shrivel and Bunch Stem Necrosis in Vitis vinifera L. CVS ‘Pinot Blanc’ and ‘Zweigelt’

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.     

Schwefelformen in Waldböden SO2-belasteter Standorte des Fichtelgebirges

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 S_t fluctuates between 37 to 943 ppm; 11–84% of S_t is S_p. Layers rich in clay contain up to 79%-S_E, whereas in sandy to silty substrates organic bound C?S-S dominates. The organic surface layers show 1.0–2.9‰ S_t, maximum in the Oh. 69–90% of S_t are C?S-S. S_p is low with a maximum in the L-horizons (9–19% of S_t). S_E is vice versa, because values increase from L (0–8% of S_t) to Oh (7–22% of S_t). 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.     

Inherent interreplicate variability during small-scale rainfall simulations

Purpose

The validity of soil erosion data is often questioned because of the variation between replicates. This paper aims to evaluate the relevance of interreplicate variability to soil and soil organic carbon (SOC) erosion over prolonged rainfall.

Materials and methods

Two silty loams were subjected to simulated rainfall of 30 mm h^?1 for 360 min. The entire rainfall event was repeated ten times to enable statistical analysis of the variability of the runoff and soil erosion rates.

Results and discussion

The results show that, as selective removal of depositional particles and crust formation progressively stabilized the soil surface, the interreplicate variability of runoff and soil erosion rates declined considerably over rainfall time. Yet, even after the maximum runoff and erosion rates were reached, the interreplicate variability still remained between 15 and 39 %, indicating the existence of significant inherent variability in soil erosion experiments.

Conclusions

Great caution must be paid when applying soil and SOC erosion data after averaging from a small number of replicates. While not readily applicable to other soil types or rainfall conditions, the great interreplicate variability observed in this study suggests that a large number of replicates is highly recommended to ensure the validity of average values, especially when extrapolating them to assess soil and SOC erosion risk in the field.

     

The influence of nitrate and ammonium fertilization on N2O release and CH4 uptake of a well-drained topsoil demonstrated by a soil microcosm experiment

The effects of the application of KNO₃ and NH₄Cl (100 kg N ha^?1) on N₂O release and CH₄ uptake by a well-aerated topsoil (porosity: 55%, water-filled pore space: 67% of the total pore space) were studied in a laboratory incubation experiment over 50 days using a soil microcosm system with an automated registration of N₂O and CH₄ fluxes. The total N₂O-N losses over 50 days were low for all treatments and amounted to 0.9 mg m^?2 for the control, 1.2 mg m^?2 for the soil columns fertilized with KNO3, and 7.3 mg m^?2 for the soil columns fertilized with NH₄Cl. The slightly elevated N₂O release after the application Of NH₄Cl was associated with the nitrification of NH₄⁺ added. Only ?0.06% of the fertilized NH₄?N was lost as N₂O. This nitrogen fertilization reduced the CH₄ uptake of the soil columns by 43% (NH₄Cl) and 21% (KNO₃), respectively.     

Huminstoffbildung während der Kompostierung

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.     

Ozone Biomonitoring with Bel-W3 Tobacco Plants in the City of Valencia (Spain)

A biomonitoring study using the ozone-sensitive bioindicator plant Nicotiana tabacum cv. Bel-W3 was conducted in the city of Valencia (eastern Spain) and surrounding areas in 2002. Plants were exposed to ambient air at seven sites, including four traffic-exposed urban sites, a large urban garden and a suburban and a rural station, for six consecutive 2-week periods using highly standardised methods. Foliar injury was registered at all stations in at least one of the exposure periods. The urban stations submitted to intense traffic showed lower ozone injury than the less traffic-exposed stations. Strong changes in the intensity of ozone injury were observed for the different exposure periods. Leaf injury was significantly related to both mean ozone values (24 and 12 h means) and cumulative exposure indices (AOT20, AOT40). However, correlation strength was moderate (r _s?=?0.39 to 0.58), suggesting that the plant response to ozone was modified by environmental factors. The use of sensitive bioindicators like tobacco Bel-W3 in cities provides complementary information to that of continuously operating air quality monitors, as the impact of ambient ozone levels is directly measured.