Figure 5

(A) Photostability of Chl a (black squares) or Chlide a (green inverted triangles) reconstituted WSCP and of LHCII (orange triangles) in comparison to Chl a in 2% (w/v) OG (red circles). The samples were illuminated with 500 µmol of photons m⁻² s⁻¹ for 0–60 min. before fluorescence measurements (excitation at 410 nm, emission F detected at the maximum of the emission spectrum). Emission before illumination: F₀. Data are expressed as means (n = 3). Mono-exponential fits are shown as continuous lines (fitting parameters in Table S1), LHCII data were not satisfactorily fit and the connecting line is reported in dash. (B) Singlet oxygen production of Chl a (black squares) or Chlide a (green inverted triangles) reconstituted WSCP and LHCII (orange triangles) in comparison to Chl a in 2% (w/v) OG (red circles). The samples were illuminated with 500 µmol red (λ > 590 nm) photons m⁻² s⁻¹ for 0–60 min before SOSG emission detection (excitation 480 nm, emission 530 nm). Data are expressed as means (n = 3), with the connecting lines in dash. (C) Spin-trap EPR measurements of ¹O₂ production in Chl a reconstituted WSCP complexes (black) and LHCII (orange). TEMPO-formation detected after illumination at 150 μmol of photons m⁻² s⁻¹ for 60 min. Background signals were subtracted.