Dissipation of excess energy triggered by blue light in cyanobacteria with CP43' (isiA)

Jean-Charles Cadoret (1) , Raphaël Demoulière , Johann Lavaud (2, 3) , Hans J. van Gorkom , Jean Houmard (4) , Anne-Lise Etienne

1 IJM (UMR_7592) - Institut Jacques Monod
2 LIENSs - LIttoral ENvironnement et Sociétés
3 CNRS - Centre National de la Recherche Scientifique
4 REG - Régulation de l'expression génétique

The chlorophyll-protein CP43V(isiA gene) induced by stress conditions in cyanobacteria is shown to serve as an antenna for Photosystem II (PSII), in addition to its known role as an antenna for Photosystem I (PSI). At high light intensity, this antenna is converted to an efficient trap for chlorophyll excitations that protects system II from photo-inhibition. In contrast to the denergy-dependent non-photochemical quenchingT (NPQ) in chloroplasts, this photoprotective energy dissipation in cyanobacteria is triggered by blue light. The induction is proportional to light intensity. Induction and decay of the quenching exhibit the same large temperature-dependence.

Mots clés: Photosystems; Chlorophyll antenna; Photoprotection; Non-photochemical quenching; Iron-stress

Domaines: Biologie végétale; Sciences de l'environnement

Jean-Charles Cadoret, Raphaël Demoulière, Johann Lavaud, Hans J. van Gorkom, Jean Houmard, et al.. Dissipation of excess energy triggered by blue light in cyanobacteria with CP43' (isiA). Biochimica biophysica acta (BBA) - Bioenergetics, 2004, 1659, pp.100-104. ⟨10.1016/j.bbabio.2004.08.001⟩. ⟨hal-01097847⟩