Table I.

Parameters of the photosynthesis model of Farquhar et al. (1980) fitted to the relationships shown in Figure 4 between net CO2 A and ci

Values of the parameters Γ* and K′ (photorespiratory compensation point and effective Km for Rubisco, respectively) were calculated from expressions given by Farquhar et al. (1980) using values of Rubisco Km and turnover rates for carboxylation and oxygenation given by de Pury and Farquhar (1997) for 25°C.

ParameterSymbolUnitsPFD/[O2]
300/21,000/2300/211,000/21
μE m−2 s−1/%
Maximum velocity of carboxylationVc,maxμmol m−2 s−168 ± 690 ± 6105 ± 38109 ± 6
Potential electron transport rateJμmol e m−2 s−140 ± 184 ± 339 ± 7105 ± 5
Mitochondrial respiration rateRdμmol m−2 s−10.7 ± 0.10.9 ± 0.11.0 ± 0.41.1 ± 0.1
Intercellular CO2 mole fraction at transition pointciμmol mol−179 ± 10145 ± 2035.9181 ± 33
Photorespiratory compensation pointΓ*μmol mol−13.435.9
Effective Km for carboxylationKμmol mol−1502.3811.9