Figure 4.

Effect of Respiratory Inhibitors on Photosynthetic Activity of C. reinhardtii Wild-Type and pgrl1 Lines Measured by Chlorophyll Fluorescence.

(A) Wild-type progenitor (black) and pgrl1 (red) lines were grown photoautotrophically in 1-liter photobioreactors operated as turbidostats at a constant biomass concentration (≈1.5 × 10⁶ cells mL⁻¹) at a light intensity of 120 μmol photons m⁻² s⁻¹ in the presence air enriched with 2% CO₂. Chlorophyll fluorescence measurements were performed under a light intensity of 150 μmol photons m⁻² s⁻¹ in the presence of 5 mM NaHCO₃. When indicated by arrows, respiratory inhibitors SHAM and myxothiazol were sequentially added at respective concentrations of 0.4 mM and 2 μM.

(B) and (C) Chlorophyll fluorescence parameter (1-qP) related to the reduction of Q_A.

(D) and (E) PSII yield in the light measured as (Fm’-Fs)/Fm’; wild-type progenitor (dark bars) and pgrl1 (white bars) lines. Shown are means ± sd (n = 3).