Publication Date:
2012-02-07
Description:
A numerical model describing xanthophyll dynamics in phytoplankton has been developed and used to investigate cellular photoprotective response. The model assumes that, under the transition from limiting to supra-saturating light, the xanthophyll cycling pigments (PX) synthesis implies first (on a time scale of tens of minutes) a stoichiometric conversion of the already existing fucoxanthin (FUCO) and then (on time scales of an hour onwards) an up-regulation of the investment of newly synthesized carbon to PX. The latter is concomitant with a reduction in the new carbon invested in FUCO production, which down-regulates the light-harvesting apparatus. We hypothesize that these dynamics play a major role in those phytoplankton species adapted to live in highly dynamic environments requiring rapid photoprotective response. In fact, under high light-induced stress, the conversion between photosynthetic and photoprotective compounds may be a metabolically efficient photoprotective mechanism not requiring the use of newly assimilated (and then energetically expensive) carbon.
Print ISSN:
0142-7873
Electronic ISSN:
1464-3774
Topics:
Biology
