Figure 1.

Light acclimation of photosynthesis and absolute glycine and serine contents in leaves of the wild type and the trxo1 mutant. Depicted are (a) net CO₂ uptake (A) and dark respiration (R_d) rates of wild-type and trxo1 plants grown in normal air (390 ppm CO₂) to growth stage 5.1³⁸ with a 12/12 h day/night cycle (20/18°C) and a light intensity of 150 µmol m⁻² s⁻¹. Fully expanded leaves were incubated into the measuring chamber of a Licor-6400. Then, A and R_d were determined for at least 15 min in each condition during alternating light/dark cycles as indicated. Absolute glycine and serine contents (b) were determined by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) as described previously.³¹ Plants were grown under the same conditions as indicated above and leaf-material harvested in the end of the dark phase (5 min prior onset of illumination) and 2, 5, and 30 min after light was switched on (150 µmol m⁻² s⁻¹). Shown are mean values ± SD from three independent biological replicates. Asterisks indicate significant alterations of the trxo1 mutant compared to the wild type according to Student’s t test (*p < .05, n.s. – not significant).