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Functional Control of Photosynthetic Nitrogen in Heterogeneous Plant Canopies

Publikation: Qualifikations-/Studienabschlussarbeit › Dissertation

Autorschaft

  • Yi-Chen Pao

Organisationseinheiten

Details

OriginalspracheEnglisch
QualifikationDoctor rerum horticulturarum
Gradverleihende Hochschule
Betreut von
  • Hartmut Stützel, Betreuer*in
Datum der Verleihung des Grades23 Sept. 2021
ErscheinungsortHannover
PublikationsstatusVeröffentlicht - 2021

Abstract

Die Akklimatisierung der photosynthetischen Eigenschaften der Blätter an schwankende Umgebungen ist ein Schlüsselmechanismus zur Maximierung der Fitness der Pflanze. Die Wahrnehmung der Lichtumgebung ist entscheidend für Arten mit kontinuierlicher Blattbildung, wie z. B. die Gewächshausgurke (Cucumis sativus L.). Um die Akklimatisierungsdynamik zu erfassen, wird angenommen, dass die Lichtinterzeption und die Ontogenese des Blattes die Akklimatisierungsprozesse prägen. Durch die Stickstoffinvestition in die Lichtaufnahme- und Lichtnutzungsfunktionen wird der ratenlimitierende Schritt in der photosynthetischen Maschinerie bestimmt. Basierend auf diesem Konzept wurde ein dynamisches Modell des Proteinumsatzes (Synthese und Abbau) implementiert. Die Stickstoffinvestition in drei photosynthetisch funktionelle Pools wurde in Abhängigkeit von Licht, Stickstoffversorgung und Blattalter simuliert mittels eines 1D-Lichtmodells (Multilayer-Modell, MLM) und eines 3D-Lichtmodells (funktionell-strukturelles Modell, FSM). Mit der Lichtabhängigkeit der Proteinsynthese war die photosynthetische Akklimatisationsreaktion auf schwankendes Licht zu erklären und die Bestandesphotosynthese mit vergleichbarer Genauigkeit sowohl mit dem MLM als auch dem FSM vorherzusagen. Unter Verwendung des MLM wurde die Optimalität der photosynthetischen Stickstoffnutzung zur Maximierung der täglichen Bestandesphotosynthese durch Manipulation der Proteinsyntheseraten quantifiziert. Die photosynthetische Stickstoffverteilung zwischen den Blättern erwies sich bei der Gewächshaussorte „Aramon“ als optimal, mit der Ausnahme, dass die Bestandesphotosynthese durch eine verstärkte akropetale Reallokation unter stickstofflimitierenden Bedingungen verbessert werden konnte. Die photosynthetische Stickstoffpartitionierung innerhalb des einzelnen Blattes war für die Sorte „Aramon“ optimal, aber nicht für die Freilandsorte „SC-50“, wenn sie in einer Einzelstammstruktur angebaut wurde, was wahrscheinlich auf die während der Züchtung entwickelte Koordination von Funktion und Struktur zurückzuführen ist. Im Gegensatz zu „Aramon“ hat „SC-50“ weniger photosynthetischen Gesamtstickstoff, doch dafür eine lichtempfindlichere Partitionierungsstrategie. Der vorgeschlagene Modellierungsrahmen liefert eine Interpretation für Akklimatisierungsmechanismen unter schwankendem Licht und ermöglicht In-silico-Manipulationen und -Tests der photosynthetischen Akklimatisierung in heterogenen Pflanzenbeständen. Mögliche Erweiterungen des Modellierungsrahmens werden diskutiert.

Zitieren

Functional Control of Photosynthetic Nitrogen in Heterogeneous Plant Canopies. / Pao, Yi-Chen.
Hannover, 2021. 177 S.

Publikation: Qualifikations-/Studienabschlussarbeit › Dissertation

Pao, Y-C 2021, 'Functional Control of Photosynthetic Nitrogen in Heterogeneous Plant Canopies', Doctor rerum horticulturarum, Gottfried Wilhelm Leibniz Universität Hannover, Hannover. https://doi.org/10.15488/11344
Pao, Y.-C. (2021). Functional Control of Photosynthetic Nitrogen in Heterogeneous Plant Canopies. [Dissertation, Gottfried Wilhelm Leibniz Universität Hannover]. https://doi.org/10.15488/11344
Pao YC. Functional Control of Photosynthetic Nitrogen in Heterogeneous Plant Canopies. Hannover, 2021. 177 S. doi: 10.15488/11344
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