Phosphatidylglycerol Depletion Induces an Increase in Myxoxanthophyll Biosynthetic Activity in Synechocystis PCC6803 Cells

Author： Domonkos Ildiko

Publisher： Oxford University Press

ISSN： 0032-0781

Source： Plant and Cell Physiology, Vol.50, Iss.2, 2009-02, pp. : 374-382

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

Phosphatidylglycerol (PG) depletion suppressed the oxygen-evolving activity of Synechocystis PCC6803 pgsA mutant cells. Shortage of PG led to decreased photosynthetic activity, which, similar to the effect of high light exposure, is likely to generate the production of reactive oxygen species (ROS) or free radicals. Protection of the PG-depleted cells against light-induced damage increased the echinenone and myxoxanthophyll content of the cells. The increased carotenoid content was localized in a soluble fraction of the cells as well as in isolated thylakoid and cytoplasmic membranes. The soluble carotenoid fraction contained carotene derivatives, which may bind to proteins. These carotene–protein complexes are similar to orange carotenoid protein that is involved in yielding protection against free radicals and ROS. An increase in the content of myxoxanthophyll and echinenone upon PG depletion suggests that PG depletion regulates the biosynthetic pathway of specific carotenoids.