Identification of ergosterol in vesicular-arbuscular mycorrhizae   总被引：1，自引：0，他引：1  

B. Frey  H. R. Buser  H. Schüepp 《Biology and Fertility of Soils》1992,13(4):229-234

Summary Ergosta-5,7,22-tri-3-enol (ergosterol) was identified by gas chromatography-mass spectrometry in roots of berseem (Trifolium alexandrinum L., cv. Landsorte) and sweet corn (Zea mays L., cv. Honeycomb-F1) infected with the vesicular-arbuscular mycorrhizal (VAM) fungus Glomus intraradices. The fungal-derived compound ergosterol was determined quantitatively in root extracts using reverse-phase high performance liquid chromatography. The concentrations of ergosterol in VAM-infected roots reached 72 g^-1 dry material in berseem and 52 g^-1 in sweet corn after 80 days of growth, whereas concentrations in non-infected roots remained below 8 g^-1 dry weight. Additionally, phytosterols such as -sitosterol, campesterol, and stigmasterol were detected in both infected and non-infected roots. Ergosterol, as a characteristic fungal substance, is proposed as an indicator of fungal biomass in the early stages of VAM infection.  相似文献   

Effect of chemical composition on the release of nitrogen from agricultural plant materials decomposing in soil under field conditions   总被引：2，自引：0，他引：2  

M. M. Müller  V. Sundman  O. Soininvaara  A. Meriläinen 《Biology and Fertility of Soils》1988,6(1):78-83

Summary In two field experiments, plant materials labelled with ¹⁵N were buried separately within mesh bags in soil, which was subsequently sown with barley. In the first experiment, different parts of white clover (Trifolium repens), red clover (T. pratense), subterranean clover (T. subterraneum), field bean (Vicia faba), and timothy (Phleum pratense) were used, and in the second, parts of subterranean clover of different maturity. The plant materials were analysed for their initial concentrations of total N, ¹⁵N, C, ethanol-soluble compounds, starch, hemicellulose, cellulose, lignin, and ash. After the barley had been harvested, the bags were collected and analysed for their total N and ¹⁵N. In the first experiment the release of N was highest from white clover stems + petioles (86%) and lowest from field bean roots (20%). In stepwise regression analysis, the release of N was explained best by the initial concentrations of lignin, cellulose, hemicellulose, and N (listed according to decreasing partial correlations). Although the C/N ratio of the plant materials varied widely (11–46), statistically the release of N was not significantly correlated with this variable. The results of the second experiment using subterranean clover of different maturity confirmed those of the first experiment.  相似文献   

Taxonomy and evolution of cultivated plants: Literature review 1985/1986     

Jürgen Schultze-Motel  Reinhard Fritsch  Karl Hammer  Peter Hanelt  Joachim Kruse  Helga I. Maas  Harald Ohole  Klaus Pistrick 《Genetic Resources and Crop Evolution》1987,35(2):421-439

Summary Important papers on taxonomy and evolution of cultivated plants published in 1985 and 1986 were compiled and briefly discussed.

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Taxonomie und Evolution der Kulturpflanzen: Literaturübersicht 1985/1986

Zusammenfassung Wichtige Arbeiten über Taxonomie und Evolution der Kulturpflanzen aus den Jahren 1985 und 1986 wurden zusammengestellt und kurz kommentiert.

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¶rt; : 1985–1986

¶rt; , 1985 1986 . .

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Growth and interactions of arbuscular mycorrhizal fungi in soils from limestone and acid rock habitats     

Ingrid M. van AarleBengt Söderström  Pål Axel Olsson 《Soil biology & biochemistry》2003,35(12):1557-1564

Arbuscular mycorrhizal (AM) development in different soil types, and the influence of AM fungal hyphae on their original soil were investigated. Plantago lanceolata, which can grow in soils of a very wide pH range, was grown in two closely related limestone soils and an acid soil from rock habitats. Plants were colonised by the indigenous AM fungal community. The use of compartmented systems allowed us to compare soil with and without mycorrhizal hyphae. Root colonisation of P. lanceolata was markedly higher in the limestone soils (30-60%) than in the acid soil (5-20%), both in the original habitat and in the experimental study. Growth of extraradical AM fungal hyphae was detected in the limestone soils, but not in the acid soil, using the signature fatty acid 16:1ω5 as biomass indicator. Analysis of signature fatty acids demonstrated an increased microbial biomass in the presence of AM fungal hyphae as judged for example from an increased amount of NLFA 16:0 with 30 nmol g⁻¹ in one of the limestone soils. Bacterial activity, but not soil phosphatase activity, was increased by around 25% in the presence of mycorrhizal hyphae in the first harvest of limestone soils. AM fungal hyphae can thus stimulate microorganisms. However, no effect of AM hyphae was observed on the soil pH or organic matter content in the limestone soils and the available P was not depleted.  相似文献   

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

Conrad Polter  Wolfgang R. Müller-Stoll 《Genetic Resources and Crop Evolution》1968,16(1):111-125

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 / -; . «» , , , . , , ( ).

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Inhibitory effects of plant phenols on the activity of selected enzymes   总被引：3，自引：0，他引：3  

Rohn S  Rawel HM  Kroll J 《Journal of agricultural and food chemistry》2002,50(12):3566-3571

Selected enzymes (alpha-amylase, trypsin, and lysozyme) were allowed to react with some simple phenolic and related compounds (caffeic acid, chlorogenic acid, ferulic acid, gallic acid, m-, o-, and p-dihydroxybenzenes, quinic acid, and p-benzoquinone). The derivatized enzymes obtained were characterized in terms of their activity. In vitro experiments showed that the enzymatic activity of the derivatives was adversely affected. This enzyme inhibition depended on the reactivity of the phenolic and related substances tested as well as on the kind of substrate applied. The decrease in the activity was accompanied by a reduction in the amount of free amino and thiol groups, as well as tryptophan residues, which resulted from the covalent attachment of the phenolic and related compounds to these reactive nucleophilic sites in the enzymes. The enzyme inhibition correlates well with the blocking of the mentioned amino acid side chains.  相似文献   

Effects of rhodium heterogeneous catalyst and isomerization conditions on linoleic acid conjugation of soybean oil     

Pakdeechanuan P  Intarapichet KO  Fernando LN  Grün IU 《Journal of agricultural and food chemistry》2005,53(4):923-927

Rhodium heterogeneous catalyst was used to catalyze isomerization of linoleic acid in soybean oil to conjugated linoleic acid (CLA). A central composite rotatable design with five levels of three variables, namely, reaction temperature, stirring speed, and reaction time, was used to determine the maximum CLA yield. The formation of CLA during isomerization was greatly dependent on the reaction temperature and time. The CLA content of soybean oil increased from 0.63 to 202.42 mg/g oil when isomerization was done at 200 degrees C, with a stirring speed of 200 rpm for 49 min. Analysis of triacylglycerol positions showed that linoleic acid at any position in a triacylglyceride could possibly be isomerized to CLA.  相似文献   

Mass spectrometric detection and formation of D-amino acids in processed plant saps, syrups, and fruit juice concentrates     

Pätzold R  Brückner H 《Journal of agricultural and food chemistry》2005,53(25):9722-9729

Liquid and syrupy dietary saps and juices of plant origin, characterized by the presence of large quantities of saccharides (glucose, fructose, or sucrose) and containing amino acids, were analyzed for the presence of D-amino acids using enantioselective gas chromatography-mass spectrometry. D-amino acids were detected in processed saps and juices of trees (maple, palm, birch), fruits (grape, apple, pear, pomegranate, date), and various other plants (agave, beetroot, sugar cane, carob). D-Ala was detected in all plant products and amounted to approximately 34% D-Ala (relative to L-Ala + D-Ala) in Canadian maple syrups, to approximately 13% in palm saps, and to 48 and 13% D-Ala, respectively, in concentrated grape juices (Spanish Arrope and Turkish Pekmez). Varying amounts and kinds of other D-amino acids were also detected. To test the hypothesis that racemization, that is, partial conversion of L-amino acids into their corresponding D-enantiomers, occurs at reversible stages of the Maillard reaction, the Amadori compound fructose-L-phenylalanine was synthesized. On heating at 200 degrees C for 5 (20) min, release of 10.8% (24.2%) D-Phe was detected. From the data it is concluded that the Amadori compounds formed in the course of the Maillard reaction are pecursors of D-amino acids in foodstuffs.  相似文献   

Mercury contamination in the Brazilian Amazon. Environmental and occupational aspects     

A. C. Barbosa  A. A. Boischio  G. A. East  I. Ferrari  A. Gonçalves  P. R. M. Silva  T. M. E. da Cruz 《Water, air, and soil pollution》1995,80(1-4):109-121

Mercury (Hg) contamination of miners, riparian and Indian populations and fish in the Amazon region, due to gold extracting activities, has been studied. Samples of hair, urine, and blood of Indians and prospectors, and hair from riparian fish-eating population and fishes from Madeira river, respectively, were collected and analyzed by Cold Vapor, Atomic Absorption Spectrometry (CV-AAS) techniques. The results obtained showed that the aquatic food chains in the Amazonian ecosystems are contaminated by methylmercury (MeHg), exposing Indians, prospectors and riverines to thr risk of severe health hazard. The highest levels of contamination, based upon hair analysis, were found in riparian of the Madeira river, followed by Cuniã Lake population, Indians (Fresco river) and prospectors, in that order. Blood analysis showed 59% of the samples from Indians and 33% from prospectors with Hg contents above 10 ng mL^?1. Analysis of urine, on the other hand, showed 44% of Indians with Hg levels below the detection limit (d.l.), and 30% above 20 ng mL^?1, whereas 38% of the prospectors presented Hg concentrations over 20 ng mL^?1, and 20% below the d.l. These results prove that prospectors, who hardly ever eat fish but are badly exposed to inorganic Hg vapor, are ocupationally contaminated, while the rest of the populations under survey are exposed to environmental contamination by Hg, through polluted fish ingestion.  相似文献   

Die urgeschichtlichen Reste des Schlafmohns (Papaver somniferum L.) und die Entstehung der Art     

Dr. Jürgen Schultze-Motel 《Genetic Resources and Crop Evolution》1979,27(2):207-215

Zusammenfassung Botanische und archäologische Befunde lassen erkennen, daß der Schlafmohn (Papaver somniferum L.) im westlichen Mittelmeergebiet entstanden ist.

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The prehistoric remains of the opium poppy (Papaver somniferum L.) and the origin of the species

Summary Botanical and archaeological data suggest the origin of the opium poppy (Papaver somniferum L.) in the Western Mediterranean region.

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(Papaver somniferum L.)

, (Papaver somniferum L). .

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