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标题：Zeaxanthin-dependent nonphotochemical quenching does not occur in photosystem I in the higher plant Arabidopsis thaliana
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作者：Lijin Tian ; Pengqi Xu ; Volha U. Chukhutsina 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2017
卷号：114
期号：18
页码：4828-4832
DOI：10.1073/pnas.1621051114
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Nonphotochemical quenching (NPQ) is the process that protects the photosynthetic apparatus of plants and algae from photodamage by dissipating as heat the energy absorbed in excess. Studies on NPQ have almost exclusively focused on photosystem II (PSII), as it was believed that NPQ does not occur in photosystem I (PSI). Recently, Ballottari et al. [Ballottari M, et al. (2014) Proc Natl Acad Sci USA 111:E2431–E2438], analyzing PSI particles isolated from an Arabidopsis thaliana mutant that accumulates zeaxanthin constitutively, have reported that this xanthophyll can efficiently induce chlorophyll fluorescence quenching in PSI. In this work, we have checked the biological relevance of this finding by analyzing WT plants under high-light stress conditions. By performing time-resolved fluorescence measurements on PSI isolated from Arabidopsis thaliana WT in dark-adapted and high-light–stressed (NPQ) states, we find that the fluorescence kinetics of both PSI are nearly identical. To validate this result in vivo, we have measured the kinetics of PSI directly on leaves in unquenched and NPQ states; again, no differences were observed. It is concluded that PSI does not undergo NPQ in biologically relevant conditions in Arabidopsis thaliana . The possible role of zeaxanthin in PSI photoprotection is discussed.
关键词：photosystem I ; NPQ ; time-resolved fluorescence ; LHCI ; light stress