Fig. 4
Pulse-amplitude modulation (PAM) fluorescence measurements of C. reinhardtii strains CC-125, Mut-5, and npq4-1 cultured at different light intensities. A Maximum photosystem II quantum yield (Fv/Fm) measurements for CC-125, Mut-5, and npq4-1 acclimated to low light (LL; 70 µmol photons m2 s−1), medium light (ML; 150 µmol photons m2 s−1), and high light (HL; 400 µmol photons m2 s−1) for 8 days. Data are represented as the mean of 3 independent replicates with error bars depicting standard deviation. For each parameter, significant differences between each strain and light condition were calculated by two-way ANOVA with a multiple comparisons test (compare cell means regardless of rows and columns) with post hoc Bonferroni correction. Means marked with the same letter are not significantly different. B–D Rise and decay kinetics of non-photochemical quenching (NPQ) in CC-125, Mut-5, and npq4-1 measured following acclimation to B LL, C ML, and D HL conditions. Dark-adapted cells were subjected to illumination with saturating white actinic light (1630 µmol photons m2 s−1) in intervals for 8 min, followed by relaxation in the dark. White and black bars above the plots represent illuminated and dark periods, respectively