Figure 1.

Chlorophagy occurs in pub4-6 mutant leaves. A, Confocal images of wild-type (WT), pub4-6, and atg5 mesophyll cells expressing chloroplast stroma-targeted (CT)-GFP from either nontreated control plants or plants 2 d after HL (2,000 µmol m⁻² s⁻¹) exposure for 2 h at 10°C. Chlorophyll (magenta) and CT-GFP (green) signals are shown. In the merged images, overlapping regions of chlorophyll and GFP appear white. Only merged images are shown for atg5 plants. Arrowheads indicate CT-GFP-deficient chloroplasts. Bars = 10 µm. B, F_v/F_m ratios measured before (Cont.) and immediately after HL treatment for 2 h at 23°C (HL) or at LT (HL+LT; 10°C). Error bars indicate se (n = 4). C, Proportions of cells with stromal CT-GFP-deficient chloroplasts in a fixed region, measured 2 d after HL treatment. Error bars indicate se (n = 4). D, Confocal images of wild-type, pub4-6, and atg5 mesophyll cells expressing the tonoplast marker VHP1-mGFP from either nontreated control plants or plants 2 d after HL treatment for 2 h at 10°C. Chlorophyll (magenta) and VHP1-mGFP (green) signals are shown. Only merged images are shown. Arrowheads indicate vacuole-enclosed chloroplasts. Bars = 10 µm. E, Proportions of cells with vacuole-enclosed chloroplasts in the fixed region, measured 2 d after HL treatment for 2 h at 10°C. Error bars indicate se (n = 4). In B, C, and E, different letters denote significant differences based on Tukey’s test (P < 0.05).