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Ilík P, Pavlovič A, Kouřil R, Alboresi A, Morosinotto T, Allahverdiyeva Y, Aro EM, Yamamoto H, Shikanai T. Alternative electron transport mediated by flavodiiron proteins is operational in organisms from cyanobacteria up to gymnosperms. New Phytol 2017; 214:967-972. [PMID: 28304077 DOI: 10.1111/nph.14536] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 02/28/2017] [Indexed: 05/09/2023]
Abstract
Photo-reduction of O2 to water mediated by flavodiiron proteins (FDPs) represents a safety valve for the photosynthetic electron transport chain in fluctuating light. So far, the FDP-mediated O2 photo-reduction has been evidenced only in cyanobacteria and the moss Physcomitrella; however, a recent phylogenetic analysis of transcriptomes of photosynthetic organisms has also revealed the presence of FDP genes in several nonflowering plant groups. What remains to be clarified is whether the FDP-dependent O2 photo-reduction is actually operational in these organisms. We have established a simple method for the monitoring of FDP-mediated O2 photo-reduction, based on the measurement of redox kinetics of P700 (the electron donor of photosystem I) upon dark-to-light transition. The O2 photo-reduction is manifested as a fast re-oxidation of P700. The validity of the method was verified by experiments with transgenic organisms, namely FDP knock-out mutants of Synechocystis and Physcomitrella and transgenic Arabidopsis plants expressing FDPs from Physcomitrella. We observed the fast P700 re-oxidation in representatives of all green plant groups excluding angiosperms. Our results provide strong evidence that the FDP-mediated O2 photo-reduction is functional in all nonflowering green plant groups. This finding suggests a major change in the strategy of photosynthetic regulation during the evolution of angiosperms.
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Affiliation(s)
- Petr Ilík
- Department of Biophysics, Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University, 783 71, Olomouc, Czech Republic
| | - Andrej Pavlovič
- Department of Biophysics, Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University, 783 71, Olomouc, Czech Republic
| | - Roman Kouřil
- Department of Biophysics, Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University, 783 71, Olomouc, Czech Republic
| | | | | | - Yagut Allahverdiyeva
- Department of Biochemistry, Molecular Plant Biology, University of Turku, 20014, Turku, Finland
| | - Eva-Mari Aro
- Department of Biochemistry, Molecular Plant Biology, University of Turku, 20014, Turku, Finland
| | - Hiroshi Yamamoto
- Department of Botany, Graduate School of Science, Kyoto University, 606-8502, Kyoto, Japan
- CREST, Japan Science and Technology Agency, Chiyoda-ku, 102-0076, Tokyo, Japan
| | - Toshiharu Shikanai
- Department of Botany, Graduate School of Science, Kyoto University, 606-8502, Kyoto, Japan
- CREST, Japan Science and Technology Agency, Chiyoda-ku, 102-0076, Tokyo, Japan
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