FIGURE 3.

The FdC1 protein is imported into A. thaliana chloroplasts and has increased abundance on PSI acceptor limitation. A, import of FdC1 pre-protein into chloroplasts. Isolated protoplasts were transformed and after an overnight incubation in darkness, GFP expression and localization were visualized by fluorescence microscopy. Chlorophyll autofluorescence, fluorescence of GFP-FdC1 proteins, merged image of chlorophyll, and GFP fluorescence and a bright field image of the same (typical) protoplast are shown. B, increased FdC1 abundance in conditions of PSI acceptor limitation. Western blots were performed with protein extracts from WT and fd2 plants, either treated for 6 h with high light (HL+) or left in growth light conditions (HL−). Lanes were loaded with 25 μg of protein, and detection was performed using antisera raised against FdC1 (then purified against the recombinant protein). Identical blots were challenged with antisera raised against the small subunit of Rubisco (SSU) as a loading control. 10 ng of recombinant FdC1 was loaded as a control. Blots are typical of two independent experiments.