Figure 5.

mes16 mutants retain FCCs in the vacuoles. A, Protoplasts and vacuoles were isolated from mes16-1, and colorless catabolites were separated by HPLC as described in “Materials and Methods.” For clarity, only a part of the HPLC traces is shown. For identification and peak numbering of FCCs and NCCs, see Table I. B, Palisade mesophyll of dark-induced leaves (4 d) of Col-0 and mes16-1 observed with a laser scanning confocal microscope. FCC fluorescence was induced with an excitation wavelength of 355 nm, and the emission signal (blue) was recovered between 430 and 470 nm. Red is Chl autofluorescence. Bars = 50 μm. C, FCC-to-NCC isomerization assays performed with pFCC (black squares) or O13⁴-desmethyl pFCC (black circles). Relative concentrations of FCCs and corresponding NCCs are plotted for pH 5 and 6. For more details, see “Materials and Methods.” Calculated half-lives of FCCs are listed in Table II.