Fig. 3.

Average photosynthetic rates (A, μmol m⁻² s⁻¹) of the wild-type (WT) and bifunctional FBP/SBPase-expressing (FS) plants in comparison. Morning (A), midday (B), and afternoon (C) in situ gas exchange measurements were pooled for all four treatments (ambient/elevated CO₂, control/heated plots) and for all sampling days in the respective years. Temperature, reference [CO₂], and light (photosynthetic active radiation, PAR) in the LI-6400XT leaf chamber were set to match ambient conditions at the beginning of the measurements and the values were maintained throughout the course of all measurements at the respective time point. Relative humidity (RH) was kept between 50% and 70% during the measurements. Environmental conditions during the in situ measurements are presented in Table 2. Error bars are ±SE of the LS means estimate as derived from a repeated measures ANOVA (Supplementary Table S1). Symbols mark significant differences between WT (empty bars) and FS (gray bars) (• <0.1, * <0.05, ** <0.01, *** <0.001). Note that the y-axis does not start at zero.