Figure 7.

The responses of the apparent K_m for CO₂ (A) and the maximal carboxylation rate (V_cmax) (B) of the Val-335 Rubisco to pO₂ inferred from gas-exchange data. The data were calculated from CO₂-response curves similar to those in Figure 6A measured at different pO₂ as described by von Caemmerer et al. (1994). An infinite conductance for CO₂ transfer between the intercellular air spaces and the sites of carboxylation was assumed. The solid line in A is a linear fit to the data for one transformant plant (▪). For comparison, the dashed line shows the in vivo response of the wild-type Rubisco (Leu-335) calculated from the data of von Caemmerer et al. (1994) for Rubisco-deficient anti-rbcS tobacco.