Fig. 2.

Changes in activity of photorespiration and its related pathways in mitochondria during diurnal cycle in Arabidopsis shoot. A, oxygen consumption dependent on glycine as substrate and supplemented with appropriate cofactors was measured. B, the catalytic activity of FDH and OAS-TL and the formate-dependent oxygen consumption rate were measured. Enzyme activity profiles are plotted with respect to 0 h (100%), and glycine- and formate-dependent oxygen consumption measurements are presented as nmol min⁻¹ mg⁻¹ of protein. Data were compared using a one-way ANOVA cutoff of p < 0.05 with an asterisk (*) indicating significant differences between 10 data points. A Tukey analysis is shown in supplemental Table 3. The results are shown as means of biological replicates and error bars are S.E. (n = 3). The day/night cycle is indicated at the top of the plot by a white (day) and a black (night) bar.