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Alternative electron transport mediated by flavodiiron proteins is operational in organisms from cyanobacteria up to gymnosperms
Author(s) -
Ilík Petr,
Pavlovič Andrej,
Kouřil Roman,
Alboresi Alessandro,
Morosinotto Tomas,
Allahverdiyeva Yagut,
Aro EvaMari,
Yamamoto Hiroshi,
Shikanai Toshiharu
Publication year - 2017
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.14536
Subject(s) - physcomitrella patens , photosynthesis , p700 , photosystem i , arabidopsis , cyanobacteria , botany , electron transport chain , biology , chloroplast , redox , photosystem , biophysics , chemistry , photosystem ii , gene , mutant , biochemistry , genetics , bacteria , organic chemistry
Summary Photo‐reduction of O 2 to water mediated by flavodiiron proteins ( FDP s) represents a safety valve for the photosynthetic electron transport chain in fluctuating light. So far, the FDP ‐mediated O 2 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 O 2 photo‐reduction is actually operational in these organisms. We have established a simple method for the monitoring of FDP ‐mediated O 2 photo‐reduction, based on the measurement of redox kinetics of P700 (the electron donor of photosystem I) upon dark‐to‐light transition. The O 2 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 FDP s 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 O 2 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.