Reference : Light-induced photosynthetic electron transfer upon anaerobiosis in Chlamydomonas : k...
Scientific congresses and symposiums : Unpublished conference/Abstract
Life sciences : Biochemistry, biophysics & molecular biology
Life sciences : Phytobiology (plant sciences, forestry, mycology...)
http://hdl.handle.net/2268/151470
Light-induced photosynthetic electron transfer upon anaerobiosis in Chlamydomonas : kinetics, electron sinks and setup of a fluorescence screen to identify new players.
English
Godaux, Damien mailto [Université de Liège - ULiège > Département des sciences de la vie > Génétique >]
Emonds-Alt, Barbara mailto [Université de Liège - ULiège > Département des sciences de la vie > Génétique >]
alric, Jean []
Ghysels, Bart mailto [Université de Liège - ULiège > > Labo de Bioénergétique >]
Remacle, Claire mailto [Université de Liège - ULiège > Département des sciences de la vie > Génétique >]
Cardol, Pierre mailto [Université de Liège - ULiège > Département des sciences de la vie > Génétique >]
6-Jun-2012
In Chlamydomonas reinhardtii, prolonged anaerobiosis leads to the expression of various fermentative pathways. Among them, oxygen-sensitive hydrogenases (hyd) catalyze the reduction of protons from reduced ferredoxin resulting in the production of molecular hydrogen. In this work, light-induced photosynthetic electron transfer after a prolonged dark-anaerobiosis period was studied by following the kinetics of chlorophyll fluorescence emission, P700 oxidation and proton-motive force formation and consumption during the first 3 seconds of illumination. We show that during the induction of photosynthesis, an hyd-dependent photosynthetic electron transfer operates at a maximal rate of 110 electrons per photosystem per second, that is about half the one measured in aerobiosis. The implication in this process of components of the linear, cyclic and chlororespiratory electron transfer pathways, as well as of various electron sinks, are investigated thanks to the availability of mutants. In a next step, we screen an insertional mutant library (~3000 clones) on the basis of the fluorescence induction kinetics upon a shift from dark-anaerobiosis to light. Five mutants display the
signature of mutants deficient for NADPH:PQ oxidoreductase or hyd activities. In particular, one is defective for
hydrogenase HydG assembly factor. This mutant behaves exactly has the hydEF mutant, thus confirming that in vivo both the assembly factors are required for an efficient hydrogenase activity.
Yes
No
International
15th Conference on the Cell & Molecular Biology of Chlamydomonas
du 5 au 10 juin 2012
Potsdam
Germany
http://hdl.handle.net/2268/151470

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