Fig. 7.

Chlamydomonas cells integrate two light inputs to cope with light stress. (A–C) Photosystem II capacity, as determined by Fv/Fm values over the diurnal cycle, in cultures exposed to 200 µmol photons/m²/s with abrupt (A) or gradual 2-h transition at dawn (B), or exposed to 60 µmol photons/m²/s with abrupt transition at dawn (C). Relative (rel) mRNA abundance for LHCSR3.1 (D–F) and PSBS2 (G–I) by quantitative RT-PCR, in samples collected from cells grown under diurnal conditions with 200 µmol photons/m²/s with abrupt transition at dawn (D and G), 200 µmol photons/m²/s with gradual transition at dawn (E and H), or 60 µmol photons/m²/s with abrupt transition at dawn (F and I). All data are shown as average ± SD (n = 3). rel, relative.