Mesophyll conductance (gm) and
chloroplast CO2 concentrations (Cc)
Leaf g m to CO2 and C c were
calculated from the combined gas exchange and other parameters (Harley
et al., 1992). The g m in VC was 0.05 mol
CO2 m–2 s–1bar–1 and C c was substantially
lower than C i (173 μmol CO2mol–1 at 319 μmol CO2mol–1). In the two transgenics,g m increased to 0.069 or 0.073 mol
CO2 m–2 s–1bar–1 which led to significantly higherC c (8% - 10%) than in the VC. Although we had
problems in accurately measuring g m andC c because of the small size ofArabidopsis leaves, yet, we consistently observed small increases
in C c for FbβCA3 overexpressors over the
VC.