Fig. 5

Photosynthetic activity of WT and std1 Chlamydomonas cells during mixotrophic or photoautotrophic N deprivation. PSII yields were determined at different light intensities in the std1 mutant, in the WT and in two complemented mutant lines by measuring pulse amplitude-modulated chlorophyll fluorescence. Cells were grown under a light intensity of 100 µmol photons m⁻² s⁻¹ under a Photoautotrophic conditions (i.e., MM supplemented with 2 % CO₂) or b Mixotrophic conditions (i.e., TAP). At t ₀, cells were resuspended in an N-free medium and fluorescence measurements were performed at t₀ (N-replete) and after 2 and 3 days of N deprivation. Data are means ± SD (n = 6 for a, and n = 4 for b)