Manfred Tesche

Abscisic Acid and its ß-D-Glucopyranosyl Ester in Saplings of Scots Pine (Pinus sylvestris L.) in Relation to Water Stress

Summary In different shoot parts of Scots pine saplings abscisic acid (ABA) and its s-D-glucopyranosyl ester (ABA-glu) have been identified by chromatographical methods and mass spectrometry. Changes in the endogenous levels of ABA and its main metabolite ABA-glu have been determined by gas chromtography in relation to water stress (1, 2 and 4 h) and rewatering (30 min and 4 h). At the beginning of water stress ABA increased in young shoots and the needles of older parts, but decreased in the axis. Simultaneously an ABA-glu peak occurred especially in the needles indicating that both ABA biosynthesis and metabolism are stimulated by water stress. During 30 min rewatering the ABA level increased in all shoot parts, most intensively in the axis. From the results obtained it can be concluded that the increase of free ABA level at the beginning of water stress is based mainly on ABA biosynthesis, whereas during rewatering a partial re-activation of ABA-glu might be involved.

Der Einfluß von Schwefeldioxid und Frost auf Fichten (Picea abies (L.) Karst.)

Summary After fumigation with experimentally generated low concentration of sulphur dioxide and sublethal freezing during the winter season the following changes could be noted with young spruces in autumn, shortly before, and in spring, at the end of the growing season: as a consequence of immission stress a depression of the net photosynthesis occurred without the stomata regulation capability being impaired. In spring the starch content of young shoots of the last year increased much less than that of the control plants. There was an increase of the electrolyte content within the diffusate from last-year shoots and the carbohydrate exsudation from roots as well. Freezing generally enhanced the permeation of substances from young shoots and roots, especially with plants exposed to SO2. It is supposed that the increased frost sensitivity of SO2 — stressed plants is associated with a disturbance of controllability of the membrane permeability.

In vivo pH measurement in the xylem of broad-leaved trees using ion-sensitive field-effect transistors

SummaryA new method of in vivo pH determination in the xylem of broad-leaved trees using ion-sensitive field effect transistors is developed and its suitability for use is studied. In the first few hours after the sensor had been implanted in the xylem signals could be detected which were generated in response to mechanical damage; particularly strong signal changes are detectable in Populus balsamifera L., Tilia cordata Mill, and Aesculus hippocastanum L. The pH values of the xylem sap extracted from branches corresponded to the values measured by the in vivo method only at certain times. Due to sensor drift the measuring accuracy of long-term experiments lasting up to 3 weeks is restricted. The in vivo measurement of pH in the xylem of poplar branches revealed the ability of the living xylem to buffer the pH of the sap to its own characteristic value.

Streß und Decline bei Waldbäumen

ZusammenfassungStreß und Decline sind zwei Begriffe, die im Zusammenhang mit aktuellen Waldschäden in unterschiedlicher Weise verwendet werden. Es wird anhand von Beispielen dargestellt, daß- Wirkungen von komplexem Umwelstreß nicht nur vom genotypischen Reaktionsvermögen der Pflanzen und der Streßintensität sondern auch von der Kombination und Konstellation sowie von der Art und Weise des Einwirkens einzelner Stressoren abhängen,- schwache, zeitlich begrenzte Streßintensitäten einen Adaptationsreiz auf Pflanzen ausüben können, der als Eustress bezeichnet werden sollte und- komplexe Streßsituationen nicht zwangsläufig zu einer Verstärkung der Wirkung einzelner Stressoren und damit zum Distreß führen müssen. Für das Erkennen von Abwehr- bzw. Adaptationsreaktionen sind Untersuchungen während oder unmittelbar nach dem Streß (instant effects) nicht ausreichend. Nur im Langzeitexperiment können derartige Effekte (memory effects) erkannt werden.Aus den Ergebnissen ist zu folgern, daß das „decline-spiral-model” vonManion (1981) zu stark vereinfacht, indem es das Abwehr- und Adaptationspotential von Pflanzen außer acht läßt.SummaryStress and decline are two terms used in a different manner in connection with current forest damages. Using examples, it is demonstrated that- effects of complex environmental stress do not only depend upon the genotypic reaction capability of plants and the intensity of stress, but also on the combination and constellation as well as the way of influence exerted by individual stressors;- low stress intensities lasting for a limited time can result in an adaption stimulation for plants, which should be called eustress and- complex stress situations do not necessarily lead to an intensification of the effect caused by individual stressors and thus not to distress. Investigations carried out during or immediately after the impact of stress (instant effects) are not sufficient for diagnosing defence or adaptation reactions. Effects of this kind (memory effects) can only be identified in long-term experiments.From the results one can conclude that the “decline-spiral-model” byManion (1981) simplifies things too much, because it does not consider the defence and adaptation potential of plants.

Prolin in Bäumen Teil 1. Prolin in gesunden Bäumen

Summary In contrast to papers dealing with proline in herbaceous plants there is only a small number of papers describing the occurrence of proline in trees. However, as a stress indicator proline increases in importance with growing extent of damage and diseases of trees. A survey of the proline content in various organs of 20 different conifers and broad-leaved trees is given. The proline content is subjected to pronounced fluctuations in its daily and annual rhythm. In young seedlings proline varies with the individual development. The total proline content of the needle mass of old trees shows the effect of environmental stress in a particularly distinct manner. Fluctuations in the daily and annual rhythm of the proline content have necessarily to be taken into consideration just as changes occurring during the individual development when applying proline as a stress indicator.

Occurrence of Abscisic Acid and its ß-D-glucopyranosyl Ester in Shoot Parts of Scots Pine (Pinus sylvestris L.)

Summary In different shoot parts of Scots pine (needles, buds, wood, and bark) the contents of ABA and its s-D-glucopyranosyl ester were determined by gas chromatography and bioassay at summer and winter time. In summer the levels of ABA surmount those of ABA-glu in all parts, but at winter time the ratio of free to conjugated ABA changed. Needles contained always the highest amounts of free ABA, and the content of ABA-glu was highest in winter buds.

Fungistatische Wirksamkeit phenolischer Inhaltsstoffe der Fichte Picea abies (L.) Karst. und Einfluß von SO 2

ZusammenfassungPhenolische Inhaltsstoffe wurden aus verschiedenen Geweben von Fichte (Picea abies) extrahiert und fungistatisch wirkende Komponenten auf dem Dünnschichtchromatogramm mit Hilfe von Cladosporium cucumerinum lokalisiert. Die Substanz mit der stärksten fungistatischen Wirkung wurde isoliert und mit Hilfe von UV-, Massen-und 1H-NMR-Spektren als Isorhapontin identifiziert. Die höchsten Isorhapontingehalte in einer 15jährigen Fichte wurden in der äußeren Wurzelrinde mit 1,3%, in Stammrinde mit 0,4% und in Feinwurzeln mit 0,3% gemessen. Die Gehalte im Splintholz lagen zwischen 0,001% und 0,01% (alle Werte bezogen auf Frischmasse).Die BraunfäuleerregerPhaeolus schweinitzii undFomitopsis pinicola wurden durch Isorhapontin in vitro konzentrationsabhängig gehemmt (50%ige Wachstumshemmung bei Konzentrationen von 1,25 mM bzw. 3 mM). Die Weißfäulepilze Trametes versicolor, Heterobasidion annosum und Armillaria ostoyae wurden durch Isorhapontin nur geringfügig im Wachstum beeinträchtigt.Erste Untersuchungen 6 Monate nach Langzeitbegasung mit SO2 (0,28–0,34 ppm) ergaben im Vergleich zu unbehandelten Kontrollpflanzen eine Verringerung fungistatischer Stilbene in Feinwurzeln und Rinde (indirekter Effekt).SummaryThe paper deals with fungistatic phenols in Norway spruce (Picea abies). Phenolic substances were isolated from several tissues and chromatographed by TLC.Detected by bioassay using Cladosporium cucumerinum, the most fungistatic compound was isolated and identified by UV-, mass- and NMR-spectra as the stilbenglucoside isorhapontin. The highest amounts of isorhapontin were found in a 15-year-old spruce in the bark of root (1.3%) and stem (0.4%), and also in fine roots (0.3%). Sapwood contained between 0.001 and 0.01 % of this stilbene (all values related to green weight).The brown-rot fungi Phaeolus schweinitzii and Fomitopsis pinicola showed a depression of growth related to the concentration of isorhapontin on malt agar. Growth reduction of 50% was reached at a concentration of 1.25 mM (F. pinicola) and 3 mM (P. schweinitzii). The white-rot fungi Trametes versicolor, Heterobasidion annosum, and Armillaria ostoyae were not inhibited. First investigation results 6 months after long-term SO2-treatment (0.28–0.34 ppm) of cloned spruces showed a reduction of fungistatic stilbenes in fine roots and bark compared with untreated controls (indirect effect).

Identification techniques for Armillaria spp. and Heterobasidion annosum root and butt rot diseases

The need for a rapid and definite diagnosis of the Armillaria spp. and Heterobasidion annosum root and butt rot diseases as well as general requirements expected of a test to detect the pathogens are reviewed. As a spin‐off from more fundamental molecular biological research there has been a remarkable increase in newer methods for diagnosis (i.e., detection and identification) in recent years. These newer methods all have in common that they use structural elements of the target organisms such as proteins, polysaccharides, glycoproteins, nucleic acids, etc. for the construction of antibodies, probes and primers for detection, or to produce electrophoretic patterns to be used for classification and identification. The article presents a short description of principles, advantages, disadvantages and some perspectives of the new methods also developed for Armillaria spp. and H. annosum diagnosis compared with conventional ones, such as interfertility testing or visual inspection of the pathogens in situ and...

Peroxidaseaktivität von Fichte bei Hallimaschbefall bzw. unter Immissionseinfluß — Versuch einer Differenzierung der Streßindikation

Summary Investigations of peroxidase activity (POD) in needles, roots and cortex tissue of the root-collar of Picea abies and Picea omorika infected by Armillaria mellea s.l. revealed highly increased POD, especially in the cortex-tissue of the root collar. The increase of POD in the root-collar-tissue showed dependence on the degree of damage and on the season of the year. In spruce stressed by immissions, the POD was in needles and in root-collar-tissue likewise highly increased or in needles more increased than in the cortex of the root collar. In spruce stressed by Armillaria, the increase of POD in the cortex tissue of the root collar was always remarkably higher than in needles. Thus the possibility of a differentiation of stress-indication concerning the cause of the stress is suggested.

Ausscheidung von Kohlenhydraten und anderen Stoffen durch die Wurzeln von Koniferenjungpflanzen (quantitativer Aspekt)

Summary A quantitative analysis was made of the exudates produced by the roots of young Picea abies plants of different age and of two-year old Pseudotsuga menziesii, Larix decidua, Larix gmelinii var . japonica, Pinus nigra, Pinus sylvestris and Picea omorika seedlings after varying duration of exudation . All investigated conifer species exude carbohydrates and u. v. light absorbing substances in considerable quantities. The quantity of the exuded carbohydrates and u. v. light absorbing substances depends upon 6.1. species 6.2. age of plant, and 6.3, duration of exudation. Exemplified by spruce it is shown that depending on age of plant phosphorus compounds are also exuded. The large scatter of the trial results indicates an influence by further exogenous and endogenous factors.