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Regulation of photosystem I light harvesting by zeaxanthin [electronic resource].

Published
Washington, D.C. : United States. Dept. of Energy. Office of Basic Energy Sciences, 2014.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy
Physical Description
pages E2,431-E2,438 : digital, PDF file
Additional Creators
Lawrence Berkeley National Laboratory, United States. Department of Energy. Office of Basic Energy Sciences, European Union, and United States. Department of Energy. Office of Scientific and Technical Information
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Summary
In oxygenic photosynthetic eukaryotes, the hydroxylated carotenoid zeaxanthin is produced from preexisting violaxanthin upon exposure to excess light conditions. Zeaxanthin binding to components of the photosystem II (PSII) antenna system has been investigated thoroughly and shown to help in the dissipation of excess chlorophyll-excited states and scavenging of oxygen radicals. However, the functional consequences of the accumulation of the light-harvesting complex I (LHCI) proteins in the photosystem I (PSI) antenna have remained unclarified so far. In this paper we investigated the effect of zeaxanthin binding on photoprotection of PSI–LHCI by comparing preparations isolated from wild-type Arabidopsis thaliana (i.e., with violaxanthin) and those isolated from the A. thaliana nonphotochemical quenching 2 mutant, in which violaxanthin is replaced by zeaxanthin. Time-resolved fluorescence measurements showed that zeaxanthin binding leads to a previously unrecognized quenching effect on PSI–LHCI fluorescence. The efficiency of energy transfer from the LHCI moiety of the complex to the PSI reaction center was down-regulated, and an enhanced PSI resistance to photoinhibition was observed both in vitro and in vivo. Thus, zeaxanthin was shown to be effective in inducing dissipative states in PSI, similar to its well-known effect on PSII. Finally, we propose that, upon acclimation to high light, PSI–LHCI changes its light-harvesting efficiency by a zeaxanthin-dependent quenching of the absorbed excitation energy, whereas in PSII the stoichiometry of LHC antenna proteins per reaction center is reduced directly.
Report Numbers
E 1.99:1407239
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Note
Published through SciTech Connect.
05/28/2014.
"ark:/13030/qt5q16t7ph"
Proceedings of the National Academy of Sciences of the United States of America 111 23 ISSN 0027-8424 AM
Matteo Ballottari; Marcelo J. P. Alcocer; Cosimo D'Andrea; Daniele Viola; Tae Kyu Ahn; Annamaria Petrozza; Dario Polli; Graham R. Fleming; Giulio Cerullo; Roberto Bassi.
Univ. of Verona (Italy)
Polytechnic Univ. of Milan (Italy)
Ministry of Agriculture, Food and Forestry (Italy)
Ministry for Education, Higher Education and Future Research (Italy)
Korean Rural Development Agency (Republic of Korea)
Funding Information
AC02-05CH11231
316427
RBFR08XH0H
PJ00910603201
View MARC record | catkey: 23500280