| | The xanthophyll cycle pool size controls the kinetics of non-photochemical quenching in Arabidopsis thalianaEdited by Peter Brzezinski Received 16 November 2007; received in revised form 5 December 2007; accepted 5 December 2007. published online 14 December 2007. Abstract Arabidopsis plants overexpressing β-carotene hydroxylase 1 accumulate over double the amount of zeaxanthin present in wild-type plants. The final amplitude of non-photochemical quenching (NPQ) was found to be the same in these plants, but the kinetics were different. The formation and relaxation of NPQ consistently correlated with the de-epoxidation state of the xanthophyll cycle pool and not the amount of zeaxanthin. These data indicate that zeaxanthin and violaxanthin antagonistically regulate the switch between the light harvesting and photoprotective modes of the light harvesting system and show that control of the xanthophyll cycle pool size is necessary to optimize the kinetics of NPQ. Abbreviations: DES, de-epoxidation state of the xanthophyll cycle pool, DTT, dithiotheitol, LHCII, the main light harvesting complex of photosystem II, NPQ, Non-photochemical quenching, ΔpH, pH difference across the thylakoid membrane, qE, the ΔpH-component of NPQ, wt, wild-type plants a Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, United Kingdom b School of Biological and Chemical Sciences, Queen Mary University of London, Mile End, Bancroft Road, London E1 4NS, United Kingdom  Corresponding author.
PII: S0014-5793(07)01275-6 doi:10.1016/j.febslet.2007.12.016 © 2007 Federation of European Biochemical Societies | |
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ABSTRACT
