The cold-induced switch in direction of chloroplast relocation occurs independently of changes in endogenous phototropin levels
Fig 2
Chloroplasts avoid weak blue light under cold conditions.
(A) Diagram of the experimental conditions used to induce the cold-avoidance response with vertical or horizontal irradiation of blue light. After incubation under 25 μmol photons m-2 s-1 of blue light (BL25) with vertical irradiation at 5°C for 24 h, the WT gemmalings were irradiated by horizontal BL25. (B) Chlorophyll fluorescence images after irradiation of vertical or horizontal BL25 as shown in (A). The arrow indicates the light direction. (C) Diagram of the experimental conditions used to induce the accumulation response at 22°C and cold-avoidance response at 5°C with horizontal irradiation of vertically vibrating polarized weak BL. Ten-day-old WT sporelings were irradiated by the polarized weak BL (BL25) at 22°C for 12 h. The cells were transferred to 5°C, followed by incubation for 24 h and 60 h. (D) Chlorophyll fluorescence images after irradiation of the polarized weak BL as shown in (C). (E) P/A ratios calculated from chlorophyll fluorescence images shown in (D). Error bars indicate standard deviations.