LIGHT STRESS PHOTODYNAMICS OF CHLOROPHYLL-BINDING PROTEINS IN Arabidopsis thaliana THYLAKOID MEMBRANES REVEALED BY HIGH-RESOLUTION MASS SPECTROMETRIC STUDIES

^#Phone: 939-73-70; e-mail: ennikolaev@rambler.ru

*Institute of Biochemical Physics, Russian Academy of Sciences, 119334 Moscow, Russia;
**Department of Physiology and Plant Biochemistry, University of Konstanz, DE-78457 Konstanz, Germany;
***Institute for Energy Problems of Chemical Physics, Russian Academy of Sciences, 119334 Moscow, Russia

Received June 07, 2010; in final form, June 27, 2010

In higher plants the light energy is captured by the photosynthetic pigments that are bound to photosystem I and II and their light-harvesting complex (LHC) subunits. In this study, we examine the photodynamic changes within chlorophyll-protein complexes in the thylakoid membrane of Arabidopsis thaliana leaves adapted to low light and subsequently exposed to light stress. Chlorophyll-protein complexes were isolated using sucrose density gradient centrifugation and blue-native polyacrylamid gel electrophoresis (BN-PAGE). Proteome analysis was performed using SDS-PAGE, HPLC and high resolution mass spectrometry. We identified several rarely expressed and stress-induced chlorophyll-binding proteins, showed changes in localization of early light-induced protein family and LHC protein family members between different photosynthetic complexes and assembled/disassembled subcomplexes under light stress conditions and discuss their role in a variety of light stress-related processes.

Key words: Arabidopsis thaliana, FTICR mass spectrometry, light stress, pigment-protein complexes, thylakoid membranes.