title: Regulation and possible function of the violaxanthin cycle.
abstract: This paper discusses biochemical and regulatory aspects of the violaxanthin cycle as well as its possible role in photoprotection. The violaxanthin cycle responds to environmental conditions in the short-term and long-term by adjusting rates of pigment conversions and pool sizes of cycle pigments, respectively. Experimental evidence indicating a relationship between zeaxanthin formation and non-photochemical energy dissipation is reviewed. Zeaxanthin-associated energy dissipation appears to be dependent on transthylakoid ΔpH. The involvement of light-harvesting complex II in this quenching process is indicated by several studies. The current hypotheses on the underlying mechanism of zeaxanthin-dependent quenching are alterations of membrane properties, including conformational changes of the light-harvesting complex II, and singlet-singlet energy transfer from chlorophyll to zeaxanthin.
authors.affiliation: Institut für Pflanzengenetik und Kulturpflanzenforschung, Corrensstraße 3, D-06466, Gatersleben, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Pfündel
authors.forename: W
authors.initials: W
authors.lastname: Bilger