Figure 7.
Composition of the components of the photosynthetic electron transport chain (A), antenna organization (B), and thylakoid membrane energization (C) in Arabidopsis wild type (WT) and DGD-deficient mutants. Plants were grown under normal light conditions (120 μmol m−2 s−1). A, The contents of PSII, the cytochrome b6f complex, and PSI were determined by difference absorption spectroscopy in isolated thylakoids and then normalized to the leaf area. B, 77K chlorophyll a fluorescence emission spectra were normalized to the emission maximum of PSII-LHCII. The shifts in the emission maxima of PSII-LHCII (around 685-nm wavelength) as well as of the emission maximum of PSI-LHCI (around 730-nm wavelength) are indicative for the presence of uncoupled light-harvesting complexes in the DGD-deficient mutants. C, The generation of the proton motive force across the thylakoid membrane, measured as the amplitude of the total electrochromic absorption shift (ECST), is unaffected by DGD deficiency.