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  • 1
    Electronic Resource
    Electronic Resource
    Light-dependent net production of carbon monoxide by plants (1978)
    [s.l.] : Nature Publishing Group
    Nature 275 (1978), S. 740-741 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Fig. 1 Dependence of CO ( ) and CO2 () exchange on irradiance. Leaf temperature 28.3C; CO concentration in the gas stream supplied to the gas-exchange chamber 2.07 mm3 m-3, average CO concentration within the chamber during the experiment 4.78 mm3 m-3; CO2 concentration 250 cm3m-3; O2 concentration ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/275740a0
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  • 2
    Electronic Resource
    Electronic Resource
    Solute Uptake of Acer pseudoplatanus Cell Suspensions during Recovery from Gas Shock (1979)
    Oxford, UK : Blackwell Publishing Ltd
    Physiologia plantarum 46 (1979), S. 0 
    Details
    ISSN: 1399-3054
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: When the ambient atmosphere of Acer pseudoplatanus cells in suspension culture is rapidly changed by opening the culture flasks and gently stirring (‘mild gas-shock’) or by filtering and suspending in new medium (‘strong gas-shock’), drastic modifications of the rates of leucine, methionine, glucose, adenine, sulphate and phosphate uptake are observed. Following the gas-shock, rates of uptake rapidly decrease within a few minutes. Subsequently the rates increase again to the intial level within several hours. The uptake of potassium, which is known to be passively distributed between the medium and the interior of many plant cells, at least at high external concentrations, is apparently independent of gas-shock.The shock and recovery kinetics are similar for all solutes investigated (except K+), in particular for different solutes studied in double labelling experiments with the same batch of cells. At the maximum of the after-effect of shock, i.e. at minimum rates of uptake, uptake shows a highly reduced dependence on temperatures. Gas-shock probably inactivates, denatures, structurally alters or releases membrane macromolecules engaged in transport. These molecules are then re-synthesized and re-incorporated into the membrane during recovery.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1399-3054.1979.tb02632.x
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  • 3
    Electronic Resource
    Electronic Resource
    Electrochemical investigation of active malic acid transport at the tonoplast into the vacuoles of the CAM plantKalanchoë daigremontiana (1979)
    Springer
    The journal of membrane biology 47 (1979), S. 401-422 
    Details
    ISSN: 1432-1424
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary The membrane potential of cells in leaf slices of the CAM plantKalanchoë daigremontiana Hamet et Perrier in the light and in the dark is −200 mV on the average; it is reversibly depolarized by the metabolic inhibitors FCCP (5×10−6 m) and CN− (5×10−3 m); it shows the light-dependent transient oscillations ubiquitously observed in green cells; it is independent of the amount of malic acid accumulated in the cells (in a tested range between 30 and 140mm); and it is considerably hyperpolarized by the fungal toxin fusicoccin (30×10−6 m). Fusicoccin inhibits nocturnal malic acid accumulation in intact isolated phyllodia of the CAM plantKalanchoë tubiflora (Harv.) Hamet but does not affect remobilization of malic acid during the day. Electrochemical gradients for the various ions resulting from dissociation of malic acid, i.e., H+, Hmal− and mal2−, were calculated using the Nernst equation. With a very wide range of assumptions on cytoplasmic pH and malate concentration results of calculations suggest uphill transport of H+ and Hmal− from the cytoplasm into the vacuole, while mal2− might be passively distributed at the tonoplast. On the basis of the present data the most likely mechanism of active malic acid accumulation in the vacuoles of CAM plants appears to be an active H+ transport at the tonoplast coupled with passive movement of mal2− possibly mediated by a translocator (“catalyzed diffusion”), with subsequent formation of Hmal− (2 H++mal2−→H++Hmal−) at vacuolar pH's.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01869746
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  • 4
    Electronic Resource
    Electronic Resource
    The tonoplast functioning as the master switch for circadian regulation of crassulacean acid metabolism (2000)
    Springer
    Planta 211 (2000), S. 761-769 
    Details
    ISSN: 1432-2048
    Keywords: Key words: Circadian rhythm – Crassulacean acid metabolism – Minimal model (CAM rhythm) – Oscillator – Non-linear dynamics (CAM model) – Patchiness (leaf photosynthesis)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract. From the initial discovery of free-running endogenous circadian oscillations of Crassulacean acid metabolism (CAM) under constant conditions in the light and in air, it has been disputed whether the underlying oscillator is enzymic or biophysical. The hypothesis of a biophysical hysteresis switch or beat oscillator started from osmotic considerations of malate accumulation and remobilisation, indicating a tonoplast tension/relaxation mechanism. It then advanced to application of non-linear dynamics theory for the analysis of rhythmic and arrhythmic time series of CO2 exchange under the regime of external control parameters, mainly temperature, and the implementation of models for computer simulations of CAM rhythms. This provided strong evidence for the tonoplast functioning as a master switch for circadian regulation of CAM. Conversely, the hypothesis of an enzymic beat oscillator strongly developed on the experimental basis of phosphorylation/dephosphorylation of phosphoenolpyruvate carboxylase (PEPC) regulating the enzyme activity, and hence CO2 fixation and malate synthesis via this enzyme. It was much supported by the discovery that PEPC-kinase gene-transcription was under circadian control. However, biochemical and molecular analysis, as well as model simulation, strongly suggests that this is a secondary and not the primary oscillator. The synchronisation/de-synchronisation of leaf patches has revealed spatio-temporal characteristics of circadian rhythmicity that may open new ways for understanding biological clocks.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004250000408
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  • 5
    Electronic Resource
    Electronic Resource
    Die Salzdrüsen von Limonium vulgare (1967)
    Springer
    Planta 74 (1967), S. 1-17 
    Details
    ISSN: 1432-2048
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Durch eine Kombination von mikroautoradiographischem Chloridnachweis und elektronenoptischer Lokalisierung von Silberfällungen wurde versucht, die intracelluläre Verteilung des Chlorids und den Weg des Ions im Blatt zu verfolgen. Dabei ergaben sich unter anderem folgende Ergebnisse: 1. Es konnte ein Auftreten des Chlorids in Chloroplasten sichergestellt, im Zellkern wahrscheinlich gemacht werden. 2. Es ergaben sich Hinweise für einen apoplastischen und eine symplastischen Chloridtransport. 3. Für einen Konzentrationshub des Ions zwischen dem Plasma der Parenchymzellen und dem der Drüsenzellen konnten keine Anhaltspunkte erhalten werden.
    Notes: Summary Using a combination of microautoradiographic detection of chloride and an electronmicroscopic localisation of silver precipitation an attempt was made to elaborate the intracellular distribution of chloride and the pathway of this ion in the leaf. The main results were as follows: 1. It was shown that chloride occurs in the chloroplasts and probably also in the nuclei. 2. There are indications for an apoplastic and a symplastic transport of the chloride. 3. The findings do not suggest a rise of the chloride concentration in the cytoplasm between the parenchyma and the gland cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00385168
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  • 6
    Electronic Resource
    Electronic Resource
    Absorption and long distance transport by isolated stele of maize roots in relation to the dual mechanisms of ion absorption (1967)
    Springer
    Planta 74 (1967), S. 173-187 
    Details
    ISSN: 1432-2048
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die Ionenaufnahme durch intakte Wurzeln, isolierte Rinde und isolierte Zentralzylinder und der Ferntransport durch intakte und entrind ete Wurzeln wurden verglichen, und zwar kurz nach der Isolierung und nach Altern der Gewebe. Frisch isolierte Zentralzylinder akkumulieren Io nen nur in ganz geringem Maße oder überhaupt nicht. Von den beiden Systemen der metabolischen Ionenaufnahme, die in einem niedrigen (System 1: bis 0,5 meq/l) und in einem hohen Konzentrationsbereich (System 2: 1-50 meq/l) die Geschwindigkeit der Ionenaufnahme durch intakte Wurzeln und isolierte Wurzelrinde bestimmen, entwickelt sich während des Alterungsprozesses in isolierten Zentralzylindern System 1, nicht aber System 2. In Übereinstimmung mit diesem Befund zeigt die Analyse der Einzelfluxe am Plasmalemma und am Tonoplasten, daß nur der Influx aus der Außenlösung in das Cytoplasma beim Altern der Zentralzylinder beträchtlich ansteigt. Veränderungen beim Altern von abgeschnittenen, intakten Wurzeln und isolierter Rinde sind viel weniger ausgeprägt. Obwohl die Ionenaufnahme beim Altern isolierter Zentralzylinder steigt, verringert sich der Ferntransport, der bei frisch isolierten Zentralzylindern rein passiv ist. Die mitgeteilten Ergebnisse zeigen die ausgeprägte Permeabilität frisch isolierter Zentralzylinder und demonstrieren die Bedeutung der Wurzelrinde als ein Gewebe, das Ionen für den Ferntransport “sammelt”. Auf diese Weise werden neue Anhaltspunkte für die Theorie des symplasmatischen Transportes der Ionen in die Gefäße gewonnen.
    Notes: Summary Ion absorption and transport by intact roots, isolated cortex and isolated stele were compared shortly after tissue isolation and after aging. Absorption isotherms in the low and in the high concentration range show that in stripped-stele, which absorbs at a very low rate immediately after isolation, the capacity of system 1 but not system 2 is built up with aging. In agreement with this result analysis of individual fluxes across plasmamembrane and tonoplast reveals that only the influx from the medium into the cytoplasm increases considerably with aging of stele. Changes observed in aging excised roots and in isolated cortex are much less significant. In spite of the increase of absorption with aging by isolated stele, long distance transport, which is essentially passive through freshly stripped stele, decreases with aging. The reported results reflect the marked permeability of the plasmamembrane of fresh isolated stele, and demonstrate the importance of the cortex as a tissue “collecting” ions for long distance transport. New evidence for the theory of symplasmatic transport of ions into the xylem vessels is thus provided.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00388327
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  • 7
    Electronic Resource
    Electronic Resource
    Untersuchungen zur Physiologie der Carnivoren-Drüsen (1966)
    Springer
    Planta 68 (1966), S. 269-285 
    Details
    ISSN: 1432-2048
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die Sekretion von 36Cl- durch Gewebescheiben, die aus dem drüsentragenden Teil von Nepenthes-Kannen ausgestanzt worden waren, wurde mikroautoradiographisch untersucht. Nach der Applikation von 1–10 mM Chloridlösungen von der der Kannenaußenseite entsprechenden Fläche her waren die Drüsenzellen, die Zellgrenzen im Mesophyll (also die Zellwände einschließlich des dünnen Plasmabelags), Plasmaansammlungen und die Leitbündel besonders stark markiert. Die Drüsenzellen sind dicht mit Plasma erfüllt und wenig vacuolisiert. Die Kornzählungen zeigen, daß die Radioaktivität der verschiedenen plasmareichen Bereiche (der Drüsenzellen, der Zellgrenzen und der Plasmaansammlungen) nicht statistisch signifikant verschieden ist, während die Vacuolen viel weniger markiert sind. Diese Befunde werden im Lichte von Arisz' Theorie des symplasmatischen Transportes diskutiert. Eine artefizielle Übertragung der in den großen Vacuolen der Mesophyllzellen enthaltenen Radioaktivität auf das Cytoplasma während der Präparation kann allerdings nicht völlig ausgeschlossen werden.
    Notes: Summary The secretion of 36Cl- by tissue isolated from Nepenthes pitchers was investigated with microautoradiographic techniques. The tissue was transferred into ether at-30°C or embedded in the vacuum, following procedures described earlier (Lüttge and Weigl, 1965). The microautoradiographs which we obtained after application of 1–10 mM chloride solutions to the surface corresponding to the outside of the pitchers showed a high labelling of the gland cells, the cell borders in the mesophyll (i.e. the cell walls including the thin plasmatic layers), plasmatic particles and the conductive tissue. The gland cells have only very small vacuoles and are densely filled with cytoplasm. The grain counts show that the radioactivity in the parts of the tissue which are rich in cytoplasm (glands, cell borders, plasmatic particles) did not differ within the statistical error. The activity of the vacuoles, however, was much less. These findings are discussed in the light of Arisz' theory of symplasmatic transport. However, an artificial transfer of the radioactivity contained in the large vacuoles of the mesophyll cells to the cytoplasm during the preparation can not be entirely excluded.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00385287
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  • 8
    Electronic Resource
    Electronic Resource
    Untersuchungen zur Physiologie der Carnivoren-Drüsen (1966)
    Springer
    Planta 68 (1966), S. 44-56 
    Details
    ISSN: 1432-2048
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Der Cl--Transport durch isolierte Gewebescheiben aus dem die überdachten Drüsen tragenden Teil von Nepenthes-Kannen wurde untersucht. An der der Kannenaußenseite entsprechenden Fläche, deren cutinisierte Epidermis durch oberflächliches Anschneiden mit einer Rasierklinge entfernt wurde, nehmen die Gewebescheiben aus den Versuchslösungen Cl- durch metabolischen Trägertransport auf, während die Cl--Abgabe passiv ist. Die Cl--Sekretion durch die drüsentragende Oberfläche hängt von der Bereitstellung energiereicher Phosphate durch den Stoffwechsel ab. Zwischen dem Chloridgehalt und der caseinspaltenden Aktivität des Kannensekretes konnte eine Korrelation nachgewiesen werden.
    Notes: Summary The transport of chloride in isolated tissue from Nepenthes pitchers was investigated using 36Cl-, an Aminco-Cotlove chloride-titrator for the determinations of Cl- concentrations, and KCN and AsO 4 - -as metabolic inhibitors. The tissue was brought in contact with different experimental solutions (=medium). The surface corresponding to the outside of the pitchers was cut with a razor blade to remove the cutinized epidermal layer. At this surface the Cl- uptake from the medium is a metabolic process which depends on the Cl--concentration of the medium in a manner that corresponds to the Michaelis-Menten kinetics. The Michaelis-constant of this transport step was 3×10-2M. The Cl--efflux into the medium, however, is a passive process. The opposite surface of the tissue slices (corresponding to the inside of the pitchers) carries the glands. The chloride secretion taking place here is also dependent on metabolism. In vitro it occurs even when a high gradient of chloride concentration has been set up between the medium and the solution which is in contact with the glands. In vivo the Cl--concentration of the pitcher fluid and the amount of Cl- per gram of tissue water are almost equal. The rôle of chloride in the physiology of Nepenthes is still under investigation, A correlation between the chloride content of the pitcher fluid and its enzymatic activity (Casein-test), however, could already be demonstrated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00385370
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  • 9
    Electronic Resource
    Electronic Resource
    Evaluation of ion uptake isotherms and analysis of individual fluxes of ions (1968)
    Springer
    Planta 80 (1968), S. 52-64 
    Details
    ISSN: 1432-2048
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Mit Hilfe der von Pitman (1963) beschriebenen Methode wurde die Abhängigkeit der einzelnen Ionenfluxe am Plasmalemma und am Tonoplasten und des Ionengehaltes im Plasma und in der Vacuole von der Außenkonzentration untersucht. Die erhaltenen Kurven wurden mit Ionenaufnahmeisothermen aus der Literatur verglichen. Dabei zeigte sich, daß der Flux aus der Außenlösung in das Cytoplasma dem sogenannten System 1 und der Flux aus dem Cytoplasma in die Vacuole dem System 2 der Isothermenkinetik entspricht. Dies ist ein weiterer Beleg für die Richtigkeit der Theorie von Torii und Laties (1966a) über die Lokalisierung von System 1 und System 2 innerhalb der Zelle. Die Veränderung der im Cytoplasma und in der Vacuole enthaltenen Ionenmenge mit steigender Außenkonzentration läßt deutlich werden, daß das Plasmalemma seine Barrierenfunktion bei Konzentrationen über 1 mM verliert. Es wird diskutiert, welche Aussagen über Transportprozesse mit den beiden Methoden der Isothermenkinetik und der Effluxanalyse gemacht werden können.
    Notes: Summary The dependence of individual ion fluxes at the plasmalemma and at the tonoplast and of the amounts of ions in the cytoplasmic and vacuolar phases on external concentration was investigated using the method outlined by Pitman (1963). The results are compared with ion uptake isotherms from the literature. It is concluded that flux from the solution into the cytoplasm corresponds to system 1 and flux from the cytoplasm to the vacuole is congruent with system 2. The hypothesis of Torii and Laties (1966a) regarding the location of system 1 and system 2 within the cell is thus reemphazised. The changes of the amounts of internal ions with external concentration clearly demonstrate that the plasmalemma loses its function as a barrier at concentrations above 1 mM. The conclusions which can be drawn from investigations of isotherm kinetics and flux analysis are examined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00387189
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  • 10
    Electronic Resource
    Electronic Resource
    Phytochromabhängige Veränderungen des Wachstums und der Ionenaufnahme etiolierter Erbsenkeimlinge (1968)
    Springer
    Planta 83 (1968), S. 35-48 
    Details
    ISSN: 1432-2048
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Inhibition of internodial growth of pea seedlings by light is compensated for by increased growth of leaves. At a given time the sum of fresh weight of internodes plus the product of fresh weight of leaves times a certain factor is constant in darkness or with different periods of light. This correlation may reflect a competition of internodes and leaves for materials delivered at a lightindependent rate from the cotyledons. This hypothesis was tested by immersing roots of pea seedlings into 86Rb labelled K-solutions for one day in darkness, removing the plants from the solutions, exposing the seedlings to near or far red light and measuring the radioactivity and fresh weights of leaves and internodes separately. Radioactivity and fresh-weight were both dependent on phytochrome; i.e. inhibition of ion uptake and of growth in internodes and promotion of both processes in leaves by near red light as compared to dark or far red controls are mediated by phytochrome. Short time experiments of ion uptake by the roots show that K transport into the shoot organs is promoted by light after a lag phase of somewhat more than one hour. This interval corresponds well to the lag phase of the light induced growth inhibition of internodes. Seedlings deprived of cotyledons and roots grow well in water but exhibit no difference in growth rate of leaves and internodes in light and darkness. Light dependence is restored if the seedlings are submersed in approximately 3% sucrose solutions. This result seems to indicate that the influence of light on growth rates of leaves and internodes is dependent on the uptake of material by the cell. It seems possible that in the etiolated pea seedling light promotes growth of leaves by promoting uptake and hampers growth of internodes by inhibiting uptake of essential growth material delivered from the cotyledons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00385133
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