Open AccessAlgae displaying the diadinoxanthin cycle also possess the violaxanthin cycle
Author(s) -
Martin Lohr,
Christian Wilhelm
Publication year - 1999
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.96.15.8784
Subject(s) - violaxanthin , xanthophyll , photoprotection , phaeodactylum tricornutum , fucoxanthin , antheraxanthin , biology , carotenoid , photosynthesis , botany , biochemistry , algae , zeaxanthin , lutein
According to general agreement, all photosynthetic organisms using xanthophyll cycling for photoprotection contain either the violaxanthin (Vx) cycle or the diadinoxanthin (Ddx) cycle instead. Here, we report the temporal accumulation of substantial amounts of pigments of the Vx cycle under prolonged high-light stress in several microalgae thought to possess only the Ddx cycle. In the diatomPhaeodactylum tricornutum , used as a model organism, these pigments also participate in xanthophyll cycling, and their accumulation depends onde novo synthesis of carotenoids and on deepoxidase activity. Furthermore, our data strongly suggest a biosynthetic sequence from Vx via Ddx to fucoxanthin inP. tricornutum . This gives experimental support to the long-stated hypothesis that Vx is a common precursor of all carotenoids with an allenic or acetylenic group, including the main light-harvesting carotenoids in most chlorophyll a/c-containing algae. Thus, another important function for xanthophyll cycling may be to optimize the biosynthesis of light-harvesting xanthophylls under fluctuating light conditions.