Karl Egle

Zur Kenntnis des Lichtfeldes der Pflanze und der Blattfarbstoffe

Einleitung. Durch eine Reihe von Untersuchungen der letzten Jahre ist die schon so lange aufgeworfene Frage, welche Beziehungen zwischen den Blatt pigmenten und der Lichteinstrahlung bestehen, mehr und mehr in den Mittelpunkt der Lichtphysiologie geruckt. Die verbesserte Mestechnik des Standortlichtes (Seybold 1934a, 1934b; Lauscher und Schwabl 1934; Pettersen 1936 u. a.) und die verfeinerten Methoden der Pig mentanalyse (Kuhn, Winterstein, Spohn 1935 u. a.) konnten erfolg reich fur die Klarung der zwischen Lichtfeld und Blattfarbstoffe be stehenden Zusammenhange eingesetzt werden. Wie wichtig .die Beant wortung dieser Frage fur die Kohlensaureassimilation, Stomataregulation und ein gutes Dutzend damit in Zusammenhang stehender Probleme ist, bedarf wohl keiner weiteren Begrundung. Die Mannigfaltigkeit physiologischer Differenzierung der Pflanzen und die qualitativen und quantitativen Unterschiede der einzelnen Lichtfelder am naturlichen Pflanzenstandort bringen es mit sich, das wir zunachst keine allen Tatsachen gerecht werdende Theorie aufbauen konnen, wie sie etwa von Stahl (1909) versucht wurde. Die vorliegende Arbeit bescheidet sich daher bewust mit der Erweiterung unserer Kennt nisse.

Der Einfluss der Temperatur Auf die Lage des CO2-Kompensationspunktes

ZusammenfassungDer Begriff „CO2-Kompensationspunkt” wird im Vergleich zum Begriff „Licht-Kompensationspunkt” an Hand von Meßergebnissen erläutert. Die Lage des CO2-Kompensationspunktes ist von der Temperatur abhängig derart, daß sich bei höherer Temperatur das Gleichgewicht zwischen CO2-Aufnahme und-abgabe im belichteten Gewebe bei einem höheren CO2-Partialdruck der Umgebung einstellt. Die Temperaturkoeffizienten für die Dunkelatmung, die apparente und die gesamte Photosynthese werden in Form vonQ10-Werten wiedergegeben. Da diese Werte bei der photosynthetischen CO2 Verarbeitung wesentlich kleiner sind wie die bei photochemischen und chemischen Reaktionen beobachteten Temperaturkoeffizienten, wurde vermutet, daß der mit zunehmender Temperatur beobachtete steile Abfall der apparenten Photosynthese sowie die Temperaturabhängigkeit der Gesamtphotosynthese in Form einer Optimumkurve auf eine temperaturabhängige Veränderung der Reaktionsbedingungen zurückzuführen ist. Solche temperaturbedingten Veränderungen sind in bezug auf das CO2-Diffusionsgefälle zwischen der die Pflanze umgebenden Luft und den Reaktionsorten für die Bindung und photosynthetische Verarbeitung des Kohlendioxyds im Gewebe gegeben, so daß anzunehmen ist, daß die beobachteten Temperaturwirkungen in erster Linie auf temperaturbedingte Veränderungen physikalisch-physiologischer Größen bei dem vor der eigentlichen photochemischen und chemischen CO2-Verarbeitung stattfindenden Diffusionsvorgang zurückzuführen sind.

Über den Einfluß niedriger und hoher O2-Partialdrucke auf den Sauerstoff- und Kohlendioxidumsatz von Amaranthus und Phaseolus während der Lichtphase

SummaryCarbon dioxide and oxygen gas exchange of illuminated Amaranthus and Phaseolus leaves was measured from 0–600 ppm of CO2 in an open system.At low oxygen concentration (2% O2) the ratio of CO2 uptake to O2 evolution came close to 1.At high oxygen partial pressure (42% O2) the O2 compensation point of an Amaranthus leaf was increased and oxygen evolution was depressed. Accordingly the CO2/O2 quotients were variable; the lowest value of 1,9 differed significantly from 1,0.The oxygen and carbon dioxide compensation points of a Phaseolus leaf were increased at high oxygen concentration (42% O2) and oxygen evolution as well as carbon dioxide uptake were reduced. Therefore the ratios CO2 over O2 varied and differed greatly from 1,0.It was concluded that the nature of photosynthates is regulated by the gas composition around the leaves.Carbon dioxide and oxygen gas exchange of illuminated Amaranthus and Phaseolus leaves was measured from 0-600 ppm of CO2 in an open system.At low oxygen concentration (2% O2) the ratio of CO2 uptake to O2 evolution came close to 1.At high oxygen partial pressure (42% O2) the O2 compensation point of an Amaranthus leaf was increased and oxygen evolution was depressed. Accordingly the CO2/O2 quotients were variable; the lowest value of 1,9 differed significantly from 1,0.The oxygen and carbon dioxide compensation points of a Phaseolus leaf were increased at high oxygen concentration (42% O2) and oxygen evolution as well as carbon dioxide uptake were reduced. Therefore the ratios CO2 over O2 varied and differed greatly from 1,0.It was concluded that the nature of photosynthates is regulated by the gas composition around the leaves.

Kohlendioxid- und Sauerstoff-Gaswechsel belichteter Blätter und die CO2/O2-Quotienten bei normalen und niedrigen O2-Partialdrucken

SummaryThe O2- and CO2-exchange of detached, illuminated leaves from 18 species of plants grown in the Botanical Garden at the University of Frankfurt was measured at 22° C in an open gas stream (400 ppm CO2 supplied to the assimilation chamber) at both 2% O2 and 21% O2.At a low partial pressure of oxygen (2%) the ratios of CO2 uptake to O2 evolution were in all cases near unity, with a mean of 0.93±0.01. In normal atmosphere (21% O2) the CO2/O2 ratios were higher than those in 2% O2 and averaged 1.26±0.01.The results are interpreted as showing that oxygen is involved in the regulation of metabolism and may cause a shift in the direction of carbon flow in photosynthesizing tissue.The O2- and CO2-exchange of detached, illuminated leaves from 18 species of plants grown in the Botanical Garden at the University of Frankfurt was measured at 22° C in an open gas stream (400 ppm CO2 supplied to the assimilation chamber) at both 2% O2 and 21% O2.At a low partial pressure of oxygen (2%) the ratios of CO2 uptake to O2 evolution were in all cases near unity, with a mean of 0.93±0.01. In normal atmosphere (21% O2) the CO2/O2 ratios were higher than those in 2% O2 and averaged 1.26±0.01.The results are interpreted as showing that oxygen is involved in the regulation of metabolism and may cause a shift in the direction of carbon flow in photosynthesizing tissue.

Über das Pigment von Anthurus aseroëformis Mac Alpine

ZusammenfassungVon einem Exemplar der in der Nähe, von Heidelberg vereinzelt auftretenden tropischen ClathraceeAnthurus aseroëformis wurde eine Pigmentanalyse durchgeführt. Auf spektroskopischem, spektrographischem und chromatographischem Wege konnte der Nachweis erbracht werden, daß in diesem Basidiomyceten Lycopin als Hauptpigment vorkommt.

[O2- and CO2-exchange of illuminated leaves and the CO2/O 2 ratios at normal and low CO 2 partial pressure].

SummaryThe O2- and CO2-exchange of detached, illuminated leaves from 18 species of plants grown in the Botanical Garden at the University of Frankfurt was measured at 22° C in an open gas stream (400 ppm CO2 supplied to the assimilation chamber) at both 2% O2 and 21% O2.At a low partial pressure of oxygen (2%) the ratios of CO2 uptake to O2 evolution were in all cases near unity, with a mean of 0.93±0.01. In normal atmosphere (21% O2) the CO2/O2 ratios were higher than those in 2% O2 and averaged 1.26±0.01.The results are interpreted as showing that oxygen is involved in the regulation of metabolism and may cause a shift in the direction of carbon flow in photosynthesizing tissue.The O2- and CO2-exchange of detached, illuminated leaves from 18 species of plants grown in the Botanical Garden at the University of Frankfurt was measured at 22° C in an open gas stream (400 ppm CO2 supplied to the assimilation chamber) at both 2% O2 and 21% O2.At a low partial pressure of oxygen (2%) the ratios of CO2 uptake to O2 evolution were in all cases near unity, with a mean of 0.93±0.01. In normal atmosphere (21% O2) the CO2/O2 ratios were higher than those in 2% O2 and averaged 1.26±0.01.The results are interpreted as showing that oxygen is involved in the regulation of metabolism and may cause a shift in the direction of carbon flow in photosynthesizing tissue.

Die Größe der photosynthetischen Einheit und ihre Variabilität

Even under unsaturated conditions of light a yellow green Chlorella mutant shows a higher photosynthetic efficiency than the normal form on the basis of chlorophyll. This difference in photosynthesis is not influenced by irradiation with red light although in the mutant the ratio carotenoids:chlorophyll is four times higher than in the normal green cells. Therefore we conclude that in the mutant the efficiency of excitation transfer from carotenoids to chlorophyll is reduced. As a result of the smaller photosynthetic units fewer carotenoid molecules are in the vicinity of the chlorophyll. The average increase in the distance between the molecules of the two pigment groups results in the reduction of the excitation transfer to chlorophyll.SummaryEven under unsaturated conditions of light a yellow green Chlorella mutant shows a higher photosynthetic efficiency than the normal form on the basis of chlorophyll. This difference in photosynthesis is not influenced by irradiation with red light although in the mutant the ratio carotenoids:chlorophyll is four times higher than in the normal green cells. Therefore we conclude that in the mutant the efficiency of excitation transfer from carotenoids to chlorophyll is reduced. As a result of the smaller photosynthetic units fewer carotenoid molecules are in the vicinity of the chlorophyll. The average increase in the distance between the molecules of the two pigment groups results in the reduction of the excitation transfer to chlorophyll.

Kohlendioxid- und Sauerstoff-Gaswechsel belichteter Bltter und die CO2/O2-Quotienten bei normalen und niedrigen O2-Partialdrucken@@@O2- and CO2-exchange of illuminated leaves and the CO2/O2 ratios at normal and low CO2 partial pressure

SummaryThe O2- and CO2-exchange of detached, illuminated leaves from 18 species of plants grown in the Botanical Garden at the University of Frankfurt was measured at 22° C in an open gas stream (400 ppm CO2 supplied to the assimilation chamber) at both 2% O2 and 21% O2.At a low partial pressure of oxygen (2%) the ratios of CO2 uptake to O2 evolution were in all cases near unity, with a mean of 0.93±0.01. In normal atmosphere (21% O2) the CO2/O2 ratios were higher than those in 2% O2 and averaged 1.26±0.01.The results are interpreted as showing that oxygen is involved in the regulation of metabolism and may cause a shift in the direction of carbon flow in photosynthesizing tissue.The O2- and CO2-exchange of detached, illuminated leaves from 18 species of plants grown in the Botanical Garden at the University of Frankfurt was measured at 22° C in an open gas stream (400 ppm CO2 supplied to the assimilation chamber) at both 2% O2 and 21% O2.At a low partial pressure of oxygen (2%) the ratios of CO2 uptake to O2 evolution were in all cases near unity, with a mean of 0.93±0.01. In normal atmosphere (21% O2) the CO2/O2 ratios were higher than those in 2% O2 and averaged 1.26±0.01.The results are interpreted as showing that oxygen is involved in the regulation of metabolism and may cause a shift in the direction of carbon flow in photosynthesizing tissue.

ber den Einflu niedriger und hoher O2-Partialdrucke auf den Sauerstoff- und Kohlendioxidumsatz von Amaranthus und Phaseolus whrend der Lichtphase@@@The influence of low and high oxygen concentrations on oxygen and carbon dioxide gas exchange of Amaranthus and Phaseolus leaves during illumination

SummaryCarbon dioxide and oxygen gas exchange of illuminated Amaranthus and Phaseolus leaves was measured from 0–600 ppm of CO2 in an open system.At low oxygen concentration (2% O2) the ratio of CO2 uptake to O2 evolution came close to 1.At high oxygen partial pressure (42% O2) the O2 compensation point of an Amaranthus leaf was increased and oxygen evolution was depressed. Accordingly the CO2/O2 quotients were variable; the lowest value of 1,9 differed significantly from 1,0.The oxygen and carbon dioxide compensation points of a Phaseolus leaf were increased at high oxygen concentration (42% O2) and oxygen evolution as well as carbon dioxide uptake were reduced. Therefore the ratios CO2 over O2 varied and differed greatly from 1,0.It was concluded that the nature of photosynthates is regulated by the gas composition around the leaves.Carbon dioxide and oxygen gas exchange of illuminated Amaranthus and Phaseolus leaves was measured from 0-600 ppm of CO2 in an open system.At low oxygen concentration (2% O2) the ratio of CO2 uptake to O2 evolution came close to 1.At high oxygen partial pressure (42% O2) the O2 compensation point of an Amaranthus leaf was increased and oxygen evolution was depressed. Accordingly the CO2/O2 quotients were variable; the lowest value of 1,9 differed significantly from 1,0.The oxygen and carbon dioxide compensation points of a Phaseolus leaf were increased at high oxygen concentration (42% O2) and oxygen evolution as well as carbon dioxide uptake were reduced. Therefore the ratios CO2 over O2 varied and differed greatly from 1,0.It was concluded that the nature of photosynthates is regulated by the gas composition around the leaves.

The influence of low and high oxygen concentrations on oxygen and carbon dioxide gas exchange of Amaranthus and Phaseolus leaves during illumination

SummaryCarbon dioxide and oxygen gas exchange of illuminated Amaranthus and Phaseolus leaves was measured from 0–600 ppm of CO2 in an open system.At low oxygen concentration (2% O2) the ratio of CO2 uptake to O2 evolution came close to 1.At high oxygen partial pressure (42% O2) the O2 compensation point of an Amaranthus leaf was increased and oxygen evolution was depressed. Accordingly the CO2/O2 quotients were variable; the lowest value of 1,9 differed significantly from 1,0.The oxygen and carbon dioxide compensation points of a Phaseolus leaf were increased at high oxygen concentration (42% O2) and oxygen evolution as well as carbon dioxide uptake were reduced. Therefore the ratios CO2 over O2 varied and differed greatly from 1,0.It was concluded that the nature of photosynthates is regulated by the gas composition around the leaves.Carbon dioxide and oxygen gas exchange of illuminated Amaranthus and Phaseolus leaves was measured from 0-600 ppm of CO2 in an open system.At low oxygen concentration (2% O2) the ratio of CO2 uptake to O2 evolution came close to 1.At high oxygen partial pressure (42% O2) the O2 compensation point of an Amaranthus leaf was increased and oxygen evolution was depressed. Accordingly the CO2/O2 quotients were variable; the lowest value of 1,9 differed significantly from 1,0.The oxygen and carbon dioxide compensation points of a Phaseolus leaf were increased at high oxygen concentration (42% O2) and oxygen evolution as well as carbon dioxide uptake were reduced. Therefore the ratios CO2 over O2 varied and differed greatly from 1,0.It was concluded that the nature of photosynthates is regulated by the gas composition around the leaves.