Figure 3.

Rate of decarboxylation of ¹³C-enriched pyruvate by the TCA cycle (black bars) or pyruvate dehydrogenase (gray bars) of detached X. strumarium leaves either in the light (A) under 400 μmol mol⁻¹ CO₂, 21% O₂, 400 μmol m⁻² s⁻¹ photosynthetically active radiation, and 21°C or in the subsequent dark period (B). The experiments were done in either H₂O or D₂O. The decarboxylation rates were measured using the [¹³C]pyruvate enrichment technique and subsequent ¹³C analysis of evolved CO₂ (for details, see “Materials and Methods”).