Alternative electron transport mediated by flavodiiron proteins is operational in organisms from cyanobacteria up to gymnosperms
Language English Country Great Britain, England Media print-electronic
Document type Journal Article
PubMed
28304077
DOI
10.1111/nph.14536
Knihovny.cz E-resources
- Keywords
- O2 photo-reduction, alternative electron transport, dark-to-light transition, evolution of green plants, flavodiiron proteins, photosystem I, redox changes of P700,
- MeSH
- Cycadopsida metabolism radiation effects MeSH
- Flavoproteins metabolism MeSH
- Photosynthesis radiation effects MeSH
- Phylogeny MeSH
- Kinetics MeSH
- Oxidation-Reduction MeSH
- Cyanobacteria metabolism radiation effects MeSH
- Light MeSH
- Electron Transport MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Flavoproteins MeSH
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.
CREST Japan Science and Technology Agency Chiyoda ku 102 0076 Tokyo Japan
Department of Biochemistry Molecular Plant Biology University of Turku 20014 Turku Finland
Department of Biology University of Padova 35131 Padova Italy
Department of Botany Graduate School of Science Kyoto University 606 8502 Kyoto Japan
References provided by Crossref.org
Photosystems under high light stress: throwing light on mechanism and adaptation
