Electron paramagnetic resonance study of the electron transfer reactions in photosystem II membrane preparations from Arabidopsis thaliana

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• 作者：Guiying Chen ; Yagut Allahverdiyeva ; Eva-Mari Aro ; Stenbjö ; rn Styring ; Fikret Mamedov
• 关键词：Photosystem II ; Electron paramagnetic resonance ; Arabidopsis thaliana
• 刊名：Biochimica et Biophysica Acta (BBA)/Bioenergetics
• 出版年：2011
• 出版时间：February 2011
• 年：2011
• 卷：1807
• 期：2
• 页码：205-215
• 全文大小：770 K

文摘

Arabidopsis thaliana is widely used as a model organism in plant biology as its genome has been sequenced and transformation is known to be efficient. A large number of mutant lines and genomic resources are available for Arabidopsis. All this makes Arabidopsis a useful tool for studies of photosynthetic reactions in higher plants. In this study, photosystem II (PSII) enriched membranes were successfully isolated from thylakoids of Arabidopsis plants and for the first time the electron transfer cofactors in PSII were systematically studied using electron paramagnetic resonance (EPR) spectroscopy. EPR signals from both of the donor and acceptor sides of PSII, as well as from auxiliary electron donors were recorded. From the acceptor side of PSII, EPR signals from Q_Aˉ Fe²⁺ and Pheˉ Q_Aˉ Fe²⁺ as well as from the free Pheˉ radical were observed. The multiline EPR signals from the S₀- and S₂-states of CaMn₄O_x-cluster in the water oxidation complex were characterized. Moreover, split EPR signals, the interaction signals from Y_Z and CaMn₄O_x-cluster in the S₀-, S₁-, S₂-, and the S₃-state were induced by illumination of the PSII membranes at 5 K and characterized. In addition, EPR signals from auxiliary donors Y_D, Chl⁺ and cytochrome b₅₅₉ were observed. In total, we were able to detect about 20 different EPR signals covering all electron transfer components in PSII. Use of this spectroscopic platform opens a possibility to study PSII reactions in the library of mutants available in Arabidopsis.