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  • 1
    Electronic Resource
    Electronic Resource
    Effect of potassium deficiency on the plasma membrane H+-ATPase of the wood ray parenchyma in poplar (2004)
    Oxford, UK : Blackwell Science Ltd
    Plant, cell & environment 27 (2004), S. 0 
    Details
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The effect of K+ deficiency on the plasma membrane (PM) H+-ATPase was studied in young stems of poplar plants (Populus tremula × tremuloides) grown with low or full-strength K+ supply. Immunological assays using different antibodies were applied to test if K+ deficiency affects the amount of immunodetectable PM H+-ATPases in the stem tissue. The monoclonal antibody clone 46 E5 B11 revealed an increased abundance of PM H+-ATPases under conditions of low K+ supply, and immunolabelling experiments showed that this increase was restricted to vessel-associated cells (VACs) of the wood ray parenchyma. Replacement of the monoclonal antibody by a polyclonal antibody against PM H+-ATPase gave a specific immunoreactivity on blots as well as tissue sections too, but the labelling intensity showed no difference between plants with low or full-strength K+ supply. Measurements of extracellular H+ concentrations using non-invasive, H+-selective microelectrodes revealed a lowering of the pH at the surface of VACs and an enhancement of net efflux of H+ in plants grown with low K+ supply. The present results indicate an up-regulation of specific isoforms of the PM H+-ATPase in VACs under K+-deficient conditions and suggest a key role for these PM H+-ATPases in unloading K+ from the xylem stream.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-3040.2004.01236.x
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  • 2
    Electronic Resource
    Electronic Resource
    Hormonal physiology of wood growth in willow (Salix viminalis L.): effects of spermine and abscisic acid (1997)
    Springer
    Wood science and technology 31 (1997), S. 119-130 
    Details
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Willow cuttings from two-year-old twigs were grown in nutrient solution alone, nutrient solution with 0.1 mM abscisic acid or with the spermine. Roots and leaves emerged within three weeks and the cambium was activated in the shoot. In most cases earlywood was generated, even when the seedlings were made in late summer. In contrast to plantlets grown in regular nutrient solution, those treated with hormones either inhibited (ABA) or advanced (spermine) the formation of roots, leaves and wood. In addition, SEM observations of wood were combined with autoradiographic studies and metabolite analysis.14C-labeled photoassimilates from the leaves were unloaded from the phloem of the shoots and transported via the rays into the cambial zone and the xylem. In spermine treated plants labeled assimilates were highly concentrated in all cells of the newly built xylem. However, cells from plants treated with abscisic acid appeared only weakly labeled. Quantitative analysis of the assimilates after two-dimensional thin-layer chromatography showed that wood from spermine-treated plants accumulated 19% more assimilates than the control, while xylem from ABA-treated plants imported 81% less labeled compounds from the phloem. Thus, the results strongly support the view that hormones play a key role in wood formation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00705927
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    THz-imaging: a new method for density mapping of wood (1998)
    Springer
    Wood science and technology 32 (1998), S. 421-427 
    Details
    ISSN: 1432-5225
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary This paper presents a new technique for fast and non-intrusive density mapping of wood based on far-infrared spectroscopy. The transmission of a piece of beech 1.7 mm thick is investigated between 0.1 and 2.5 THz. In this spectral range we find wood to be fairly transparent, but density inhomogeneities and structural details such as annual rings become visible in the transmission profile. The measured absorption correlates well with the wood density independently obtained by the gravitometric-volumetric method. Thus it finally becomes possible to transform the THz images into 2-dimensional density maps.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00702799
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  • 4
    Electronic Resource
    Electronic Resource
    Histochemical localization of nucleoside triphosphatase activity in assimilate conducting plant tissue (1992)
    Springer
    Protoplasma 167 (1992), S. 145-151 
    Details
    ISSN: 1615-6102
    Keywords: ATPase ; UTPase ; Electron microscopy ; Energy-dispersive X-ray microanalysis ; Gomphrena globosa ; Histochemistry ; Hordeum distichon ; Monstera deliciosa ; Phloem
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary For the histochemical localization of nucleoside triphosphatases at the electron microscopic level, prefixed tissues were incubated with lead nitrate in addition to substrate (GOMORI reaction). While ATP and UTP as substrates gave electron-dense reaction products at the plasmalemma of sieve tubes, companion cells and phloem parenchyma cells, and at plasmodesmata in primary pitfields, AMP gave reaction products only at the tonoplast of parenchyma cells. Since electron-dense deposits also occur in cell walls and vacuoles, energy dispersive X-ray microanalysis was used to distinguish between lead deposits and lead-phosphate deposits. The latter were restricted to the symplast. Among the three plant species used, the leaf bundle phloem ofHordeum distichon showed ATPase activity largely restricted to the phloem cells, except for the thickwalled sieve tubes. Some activity also bordered the chloroplasts of the bundle sheath cells. In the C4 plantGomphrena globosa, ATPase and UTPase activities appeared to be the greater in phloem parenchyma cells than in sieve tubes. In the phloem of youngMonstera deliciosa roots, ATPase occurred not only at the plasmalemma of sieve tubes, but also around sieve-tube plastids. When compared with AMP as substrate, it appears that nucleoside triphosphates are the natural substrates of the enzyme(s) in the plasmalemma of sieve tubes and phloem parenchyma cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01403377
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  • 5
    Electronic Resource
    Electronic Resource
    High-voltage photography: a new method for optical detection of moisture distribution in wood and wood-based panel products (1998)
    Springer
    Holz als Roh- und Werkstoff 56 (1998), S. 437-444 
    Details
    ISSN: 1436-736X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Picea abies bei verschiedenen Feuchtegehalten (60, 43, 19, 0%) analysiert, wobei die Holzfeuchte jeweils nach den Aufnahmen gravimetrisch bestimmt wurde. Die Fotografien zeigen deutliche Feuchteunterschiede zwischen Kern- und Splintholz, das sich bei Reifholzbäumen gewöhnlich nicht farblich unterscheiden läßt. Außerdem traten Feuchteunterschiede zwischen Druckholz und normalem Holz klar hervor. Bezüglich des Feuchtegehalts verschiedener Holzwerkstoffe konnten Unterschiede zwischen Platten mit verschiedenem Feuchtegehalt deutlich mit der Spannungsfotografie gezeigt werden. Ebenso konnte der unterschiedliche Feuchtegehalt einzelner Plattenkomponenten klar dargestellt werden.
    Notes: Picea abies under different water conditions (60, 43, 19, 0%), determined gravimetrically by oven-drying at 103 °C after having taken the photographs. The voltage photographs show significant moisture differences between heartwood and sapwood which are usually not visible in trees with colourless heartwood. Moreover, moisture differences between compression wood and normal wood were clearly shown to exist. With regard to wood-based panel products moisture variations between different products as well as between the different components of one product were significantly observed by voltage photography and correlated to gravimetric measurements.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001070050348
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    Paper (German National Licenses)
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  • 6
    Electronic Resource
    Electronic Resource
    THz-imaging: a new method for density mapping of wood (1998)
    Springer
    Wood science and technology 32 (1998), S. 421-427 
    Details
    ISSN: 0043-7719
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary This paper presents a new technique for fast and non-intrusive density mapping of wood based on far-infrared spectroscopy. The transmission of a piece of beech 1.7 mm thick is investigated between 0.1 and 2.5 THz. In this spectral range we find wood to be fairly transparent, but density inhomogeneities and structural details such as annual rings become visible in the transmission profile. The measured absorption correlates well with the wood density independently obtained by the gravitometric-volumetric method. Thus it finally becomes possible to transform the THz images into 2-dimensional density maps.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00702799
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    Paper (German National Licenses)
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  • 7
    Electronic Resource
    Electronic Resource
    Extended iterative scheme for QCD: three-point vertices (1999)
    Springer
    The European physical journal 4 (1999), S. 381-400 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract: In the framework of a generalized iterative scheme introduced previously to account for the non-analytic coupling dependence associated with the renormalization-group invariant mass scale Λ, we establish the self-consistency equations of the extended Feynman rules (Λ-modified vertices of zeroth perturbative order) for the three-gluon vertex, the two ghost vertices, and the two vertices of massless quarks. Calculations are performed to one-loop-order, in Landau gauge, and at the lowest approximation level (r=1) of interest for QCD. We discuss the phenomenon of compensating poles inherent in these equations, by which the formalism automatically cancels unphysical poles on internal lines, and the role of composite-operator information in the form of equation-of-motion condensate conditions. The observed near decoupling of the four-gluon conditions permits a solution to the 2-and-3-point conditions within an effective one-parameter freedom. There exists a parameter range in which one solution has all vertex coefficients real, as required for a physical solution, and a narrower range in which the transverse-gluon and massless-quark propagators both exhibit complex-conjugate pole pairs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s100500050246
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    Paper (German National Licenses)
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  • 8
    Electronic Resource
    Electronic Resource
    Hormonal physiology of wood growth in willow (Salix viminalis L.): effects of spermine and abscisic acid (1997)
    Springer
    Wood science and technology 31 (1997), S. 119-130 
    Details
    ISSN: 0043-7719
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Willow cuttings from two-year-old twigs were grown in nutrient solution alone, nutrient solution with 0.1 mM abscisic acid or with the spermine. Roots and leaves emerged within three weeks and the cambium was activated in the shoot. In most cases earlywood was generated, even when the seedlings were made in late summer. In contrast to plantlets grown in regular nutrient solution, those treated with hormones either inhibited (ABA) or advanced (spermine) the formation of roots, leaves and wood. In addition, SEM observations of wood were combined with autoradiographic studies and metabolite analysis. 14C-labeled photoassimilates from the leaves were unloaded from the phloem of the shoots and transported via the rays into the cambial zone and the xylem. In spermine treated plants labeled assimilates were highly concentrated in all cells of the newly built xylem. However, cells from plants treated with abscisic acid appeared only weakly labeled. Quantitative analysis of the assimilates after two-dimensional thin-layer chromatography showed that wood from spermine-treated plants accumulated 19% more assimilates than the control, while xylem from ABA-treated plants imported 81% less labeled compounds from the phloem. Thus, the results strongly support the view that hormones play a key role in wood formation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00705927
    Library Location Call Number Volume/Issue/Year Availability
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    Paper (German National Licenses)
    Fulltext
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