Figure 5.

Light-Dependent O₂ Exchange Measured Using a MIMS in Wild-Type and pgrl1 Cells Grown under Different Light and CO₂ Conditions and Effect of Respiratory Inhibitors.

Cells were grown photoautotrophically under LL (50 μmol photons m⁻² s⁻¹) or HL (200 μmol photons m⁻² s⁻¹) in batch cultures in the presence of air or 2% CO₂ in air. O₂ exchange rates were measured using a MIMS in the presence of [¹⁸O]-enriched O₂, first during a 5-min dark period and then during a 10-min light period (600 μmol photons m⁻² s⁻¹).

(A) Net O₂ production in the light.

(B) Light-dependent O₂ uptake.

(C) and (D) Inhibition ratios of net O₂ production (C) and of light-dependent O₂ uptake (D) following incubation of cells with inhibitors of mitochondrial respiration (0.4 mM SHAM and 2 μM myxothiazol). Wild type (dark bars); pgrl1 (white bars). Shown are means ± sd (n = 3).