Premium
ENERGY DISSIPATION AND PHOTOPROTECTION MECHANISMS DURING CHLOROPHYLL PHOTOBLEACHING IN THYLAKOID MEMBRANES
Author(s) -
Miller Nathalie,
Carpentier Robert
Publication year - 1991
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1991.tb02042.x
Subject(s) - photoinhibition , thylakoid , photosystem ii , photoprotection , photobleaching , photosystem i , photochemistry , light harvesting complexes of green plants , p700 , biophysics , chemistry , photosynthesis , chlorophyll , chloroplast , biology , biochemistry , fluorescence , optics , physics , organic chemistry , gene
The kinetics of chlorophyll photobleaching were followed in whole thylakoid membranes as well as in photosystem I and photosystem II submembrane fractions. The onset of photobleaching was characterized by a slow rate which indicated the presence of energy traps implicated in the photoprotection of the bulk pigments. The pigments in photosystem I submembrane fractions bleached at a faster rate than those in photosystem II counterparts, the latter being more sensitive towards photoinhibition. An analysis of the pigment‐protein complexes isolated from whole thylakoid membranes during the course of a photobleaching experiment has shown that the core‐antenna complexes, including CP29, are more sensitive to illumination than the peripheral complexes. The absorption spectra of the CPI and CP29 complexes presented a blue shift of the red absorption maximum after partial photobleaching, indicative of a non‐homogeneous bleaching of the holochromes in these complexes. An analysis of these data points towards the involvement of CP29 in a photoprotection mechanism at the level of photosystem II. The weaker resistance of photosystem I to photobleaching relative to photosystem II and its stronger resistance to photoinhibition is discussed in terms of an energy dissipation pathway in thylakoid membranes.