Abstract
Chloroplasts change their positions in the cell depending on light condition. In the fern, Adiantum capillus-veneris prothallia, chloroplasts locate along the periclinal wall when the light comes vertically to the surface of the prothallus (Light position). In contrast, chloroplasts locate on the anticlinal wall in the dark (Dark position). In the photorelocation movement of chloroplasts, phy3/neo1 is assigned as the red light receptor. Nevertheless, we found chloroplasts in phy3/neo1 mutants (rap mutants) still relocate from dark position to light position under red light. We tested several rap mutants (rap2, rap7 and rap31) and all of those showed the red light-induced chloroplast relocation. Further, it was found that the light-positioning of chloroplasts occurred independent from the direction of red light. Photosynthesis inhibitor, DCMU, blocked this movement. These results indicate that chloroplast relocation under red light in rap mutants occurs through photosynthesis-dependent, non-directional movement of chloroplasts.
