Reference : An original adaptation of photosynthesis in the marine green alga Ostreococcus.
Scientific journals : Article
Life sciences : Phytobiology (plant sciences, forestry, mycology...)
Life sciences : Biochemistry, biophysics & molecular biology
http://hdl.handle.net/2268/36011
An original adaptation of photosynthesis in the marine green alga Ostreococcus.
English
[fr] Une adaptation originale de la photosynthèse chez l'algue marine Ostreococcus.
Cardol, Pierre mailto [Université de Liège - ULg > Département des sciences de la vie > Génétique >]
Bailleul, Benjamin [> > > >]
Rappaport, Fabrice [> > > >]
Derelle, Evelyne [> > > >]
Beal, Daniel [> > > >]
Breyton, Cecile [> > > >]
Bailey, Shaun [> > > >]
Wollman, Francis Andre [> > > >]
Grossman, Arthur [> > > >]
Moreau, Herve [> > > >]
Finazzi, Giovanni [> > > >]
2008
Proceedings of the National Academy of Sciences of the United States of America
National Academy of Sciences
105
22
7881-6
Yes (verified by ORBi)
International
0027-8424
1091-6490
Washington
DC
[en] Acclimatization/radiation effects ; Algae, Green/enzymology/physiology/radiation effects ; Cytochrome b6f Complex/metabolism ; Electron Transport ; Light ; Oxygen/metabolism ; Photosynthesis/radiation effects ; Photosystem I Protein Complex/metabolism ; Photosystem II Protein Complex/metabolism ; Seawater
[en] Adaptation of photosynthesis in marine environment has been examined in two strains of the green, picoeukaryote Ostreococcus: OTH95, a surface/high-light strain, and RCC809, a deep-sea/low-light strain. Differences between the two strains include changes in the light-harvesting capacity, which is lower in OTH95, and in the photoprotection capacity, which is enhanced in OTH95. Furthermore, RCC809 has a reduced maximum rate of O(2) evolution, which is limited by its decreased photosystem I (PSI) level, a possible adaptation to Fe limitation in the open oceans. This decrease is, however, accompanied by a substantial rerouting of the electron flow to establish an H(2)O-to-H(2)O cycle, involving PSII and a potential plastid plastoquinol terminal oxidase. This pathway bypasses electron transfer through the cytochrome b(6)f complex and allows the pumping of "extra" protons into the thylakoid lumen. By promoting the generation of a large DeltapH, it facilitates ATP synthesis and nonphotochemical quenching when RCC809 cells are exposed to excess excitation energy. We propose that the diversion of electrons to oxygen downstream of PSII, but before PSI, reflects a common and compulsory strategy in marine phytoplankton to bypass the constraints imposed by light and/or nutrient limitation and allow successful colonization of the open-ocean marine environment.
http://hdl.handle.net/2268/36011
10.1073/pnas.0802762105
http://www.pnas.org/content/105/22/7881.long
The National Academy of Sciences copyright is acknowledged

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