Fig. 1.
Biased cp-actin filament relocalization during chloroplast photorelocation movement. (A) Chloroplast avoidance response was induced by a high-intensity blue microbeam (377 μmol m−2 s−1) (10 μm in width). Arrowheads represent biased cp-actin filaments that were easily seen. (Inset) Nonbiased cp-actin filaments before chloroplast movement. (B and C) Magnified images of dynamics of cp-actin filaments in 2 chloroplasts indicated with arrows in A. Red circles, the position of moving chloroplasts; MB, the microbeam-irradiated area. (D) Movements of 4 chloroplasts during an avoidance response. Two control chloroplasts outside the irradiated area are indicated by cyan and yellow. Two chloroplasts in the irradiated area are indicated by blue and magenta. (Left Inset) shows the chloroplast positions at 5-min intervals after irradiation. Main image shows velocities. (Right Inset) shows the difference of GFP-talin fluorescence between the front and rear halves of the chloroplasts. (E) Reorganization of cp-actin filaments (indicated in black) during avoidance movement induced by continuous blue GFP excitation light irradiation. Numbers, time in seconds after irradiation. Blue and pink circles, the positions where GFP fluorescence intensities were recorded in F. (F) Change in GFP fluorescence intensity at the front and rear of the chloroplast in E. (G) Correlation between biased localization of cp-actin filaments and chloroplast speed during avoidance movements.