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  • 1
    Electronic Resource
    Electronic Resource
    Lipids and lipolytic enzymes in the trunkwood of Robinia pseudoacacia L . during heartwood formation (1996)
    Springer
    Trees 10 (1996), S. 376-381 
    Details
    ISSN: 0931-1890
    Keywords: Key words Acylesterhydrolase ; Heartwood formation ; Lipase ; Robinia pseudoacacia L. ; Phospholipases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract  The radial profile of lipase and phospholipase activities was determined in the trunkwood of Robinia pseudoacacia L. The trees were felled in November at the time of heartwood formation and alterations in the enzymatic activities were investigated across the sapwood and heartwood. Methods employed include gaschromatographic, colorimetric and enzymatic assays. On a dry weight basis, the hydrolysis of the artificial substrate p-nitrophenylpalmitate shows a maximum activity in growth ring 4; however, the assay has proved not to be specific for lipase. In contrast, lipase analyses (triacylglycerol acylhydrolase; E.C. 3.1.1.3) with an authentic substrate show activity peaks in growth rings 1 and 4. With protein as a reference the highest activity is found in growth ring 5. A similar tendency is observed for phospholipase A1 (E.C. 3.1.1.32) and phospholipase A2 (E.C. 3.1.1.4). Phospholipase C (E.C. 3.1.4.3) activity decreases towards the sapwood-heartwood boundary; negligible traces of activity are detected in the heartwood, whereas, based on the protein content, growth ring 4 yields maximal activity. Phospholipase D (3.1.4.4) exhibits the same radial pattern with regard to protein content as a reference. On a dry weight basis there is a significant increase within the sapwood area, while in the heartwood the activity drastically decreases. The enzyme activities are discussed in relation to degradative processes within the plasma membranes and the hydrolysis of reserve lipids during heartwood formation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02185641
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  • 2
    Electronic Resource
    Electronic Resource
    Lipids and lipolytic enzymes in the trunkwood of Robinia pseudoacacia L . during heartwood formation (1996)
    Springer
    Trees 10 (1996), S. 366-375 
    Details
    ISSN: 0931-1890
    Keywords: Key words Acyllipids ; Heartwood formation ; Phospholipids ; Robinia pseudoacacia L. ; Sterols
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract  The radial distribution of membrane and storage lipids was determined in the trunkwood of Robinia pseudoacacia L. The trees were felled in November at the time of heartwood formation and fluctuations in the amount and composition of phospholipids, free sterols, steryl esters, di- and triacylglycerols, and free fatty acids were investigated across the sapwood-heartwood boundary. The individual compounds were identified and quantified by thin layer chromatography, enzymatic and colorimetric assays, and by capillary gas chromatography. Phospholipids show a significant decrease towards the boundary area, and in the heartwood only trace amounts can be detected. The same pattern is observed for free sterols in the sapwood; in the heartwood, however, they reach maximum values with increasing depth of the trunk. Steryl esters exhibit a complementary behaviour by accumulating at the periphery of the heartwood. No concentration changes are found in the total amounts of diacylglycerols and free fatty acids. In contrast, the triacylglycerol concentration declines steadily across the trunk. With regard to qualitative composition, free fatty acids and the fatty acid moieties of the esterified constituents vary in their chain length from 14 to 24 carbon atoms and have up to three double bonds. A radial gradient in the ratio saturated/unsaturated fatty acids can be observed: except for the phospholipid fraction the relative amounts of unsaturated fatty acids increase in centripetal direction. Seven phospholipids were identified: phosphatidylcholine, phosphatidylserine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, diphosphatidylglycerol, and phosphatidic acid, which constitutes the major proportion. In the sterol group, sitosterol is the most abundant component. The composition of the esterified sterols remains constant across the trunk cross-section, whereas the relative frequencies of individual free sterols change markedly.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02185640
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  • 3
    Electronic Resource
    Electronic Resource
    Radioactivity in mushrooms, mosses and soil samples of defined biotops in SW Bavaria-two years after “Chernobyl” (1989)
    Springer
    Oecologia 80 (1989), S. 173-177 
    Details
    ISSN: 1432-1939
    Keywords: Cesium isotopes ; Chernobyl ; 40K ; Mushrooms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Mushrooms, the moos/grass layer and soil samples have been collected in autumn 1987 from two sites in SW-Bavaria in continuation of a former investigation (Elstner et al. 1987). There were still relatively high amounts of 137Cs and 134Cs in all samples. The ratio 137Cs/134Cs changed according to the different half-life times of the two radioisotopes, indicating in nearly all cases the Chernobyl accident as source. The distribution of the radioisotopes within the mushroom populations shows considerable variation, even within the same species and location. Besides 137Cs, 134Cs and 40K no other radioisotopes were detected.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00380147
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  • 4
    Electronic Resource
    Electronic Resource
    Buchbesprechungen (1975)
    Springer
    Naturwissenschaften 62 (1975), S. 143-143 
    Details
    ISSN: 1432-1904
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00623286
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  • 5
    Electronic Resource
    Electronic Resource
    Natural and Chernobyl-caused radioactivity in mushrooms, mosses and soil-samples of defined biotops in SW Bavaria (1987)
    Springer
    Oecologia 73 (1987), S. 553-558 
    Details
    ISSN: 1432-1939
    Keywords: 137Cesium ; Cesium uptake ; Chernobyl accident ; 40K ; Mushrooms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Different mushrooms, mosses and corresponding soil samples have been collected mainly from two sites in the alpine region of southwestern Bavaria. At the end of the growthseason, September 1986, gamma spectroscopic analysis showed that the moss-, mould, and needle-layer contained considerably more 134Cs and 137Cs activity per unit fresh weight than eight different species of mushroom. These two isotopes were carried into the biotop mainly as a consequence of the Chernobyl accident. 131J could not be found any more in the samples ca. 5–6 months after the catastrophe. The activity of the cesium isotopes decreased with increasing soil depth. In the mushrooms the activity was relatively high in Xerocomus badius and surprisingly low in Boletus edulis; samples of the latter and of Cantharellus cibarius collected in September 1985 (before the accident) and kept deep frozen contained almost identical amounts of 137Cs as those collected from August to October 1986. Mushrooms contained considerably more of the natural isotope 40K than the needlelayers and the soil samples in the neighbourhood. In all mushrooms except Xerocomus badius the activity of 40K was generally higher than the 137Cs activity. The results indicate that except Xerocomus badius the analyzed mushrooms do not actively take up Cs from the soil, in contrast to K.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00379415
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  • 6
    Electronic Resource
    Electronic Resource
    Concentration gradients of free sterols, steryl esters and lipid phosphorus in the trunkwood of Scot's pine (Pinus sylvestris L.) (1987)
    Springer
    Trees 1 (1987), S. 79-81 
    Details
    ISSN: 1432-2285
    Keywords: Free sterols ; Heartwood ; Pinus sylvestris L ; Sapwood ; Steryl esters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The amounts of free sterols, steryl esters and lipid phosphorus were determined in the sapwood and heartwood of mature, and in the outer and inner sapwood of young Pinus sylvestris trees. In the mature trees (up to 70 years old) the heartwood contains significantly higher amounts of free sterols than the sapwood. No radial gradient can be demonstrated in the amounts of steryl esters. Lipids extracted from the sapwood contain higher amounts of phosphorus than those from the heartwood. Stems of young Pinus sylvestris trees (up to 13 years old) show in the inner sapwood higher amounts of both free sterols and steryl esters than the peripheral younger wood zone. The inner sapwood of the young stems shows slightly higher amounts of lipid phosphorus than the outer sapwood. The results indicate that Pinus sylvestris accumulates both free sterols and steryl esters in the stems at a very early stage of the life cycle. Sterol accumulation in the innermost parts of the stems seems not to depend on heartwood formation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00203574
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