Fig. 3.

Reorganization of cp-actin filaments during chloroplast photomovement in phot1, phot2, and phot1phot2 mutants. (A–F) Chloroplast movement was induced by continuous irradiation with a microbeam (MB; 10 μm in width). Cp-actin filament behaviors under high-intensity blue light (377 μmol m⁻² s⁻¹) were observed every 5 min (A–C). Those under low-intensity blue light (3.8 μmol m⁻² s⁻¹) were observed every 10 min (D–F). Red circles indicate moving chloroplasts. Blue circles indicate lack of transient disappearance of cp-actin filaments in phot2 mutant under high-intensity blue light. (G–J) Disappearance of cp-actin filaments after 5 min of high-intensity blue microbeam irradiation (30 μm in width) (G) and increase after 10 min of low-intensity blue microbeam irradiation (the same width) (H) occurred in the WT but not in the phot1phot2 double mutant. Motility of chloroplasts located inside the microbeam area was determined as the integrated distance traveled for 60 min under high-intensity (I) or low-intensity (J) blue light. Data of G–J are presented as means and SEs derived from 7 independent experiments.