Abstract
Chloroplasts exhibit light-directed movement in plant cells to optimize their photosynthetic ability. Phototropins (phot1 and phot2 in Arabidopsis) relay light-intensity information to chloroplasts, which move toward weak light and avoid from strong light. Chloroplast-actin (cp-actin) filaments are vital to chloroplast photorelocation movement. To understand the mechanism by which the chloroplast movement is regulated, we observed cp-actin filaments visualized by expressing GFP-tagged talin in different genetic backgrounds using confocal microscopy. Our observation reconfirmed the cp-actin filament behaviors reported by Kadota et al (1) and further validated the functions of phototropins in reorganization of cp-actin filaments. Furthermore, observation of cp-actin filaments in several chloroplast movement mutants suggested that factors such as CHUP1, JAC1, PMI2, etc play a role in cp-actin filament dynamics, respectively. Functional roles of the factors will be discussed in cp-actin filament dynamics.
(1) PNAS 2009 Aug 4;106(31):13106-11.
