LHCII Populations in Different Quenching States Are Present in the Thylakoid Membranes in a Ratio that Depends on the Light Conditions.
LHCII is the major antenna complex of plants and algae, where it is involved in light harvesting and photoprotection. Its properties have been extensively studied in vitro, after isolation of the pigment-protein complex from the membranes, but are these properties representative for LHCII in the thylakoid membrane? In this work, we have studied LHCII in the cells of the green alga C. reinhardtii acclimated to different light conditions in the absence of the other components of the photosynthetic apparatus. We show that LHCII exists in the membranes in different fluorescence quenching states, all having a shorter excited-state lifetime than isolated LHCII in detergent. The ratio between these populations depends on the light conditions, indicating that the light is able to regulate the properties of the complexes in the membrane.
Department of Physics and Astronomy, Faculty of Sciences and LaserLaB Amsterdam, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
Lijin
L
Tian
Department of Physics and Astronomy, Faculty of Sciences and LaserLaB Amsterdam, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
Emine
E
Dinc
Department of Physics and Astronomy, Faculty of Sciences and LaserLaB Amsterdam, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
Roberta
R
Croce
D016825:Chlamydomonas reinhardtii / Q000378:metabolism; D008027:Light; D045342:Light-Harvesting Protein Complexes / Q000737:chemistry* / Q000378:metabolism; D010788:Photosynthesis / Q000187:drug effects / Q000528:radiation effects; D013050:Spectrometry, Fluorescence; D020524:Thylakoids / Q000187:drug effects / Q000378:metabolism*; D014815:Vitamins / Q000494:pharmacology
D045342:Light-Harvesting Protein Complexes; D014815:Vitamins
light-harvesting complexes; photosynthesis; quenching; thylakoid membrane; time-resolved fluorescence