Table II. Summary of leaf gas exchange and photosynthetic enzyme activity

Data represent averages of at least three replicates ± se. Statistical significance tests were conducted using a one-way ANOVA (*P > 0.05). NM, Not measured.

ParameterWild TypeUBIRBCSPEPC (H)PEPC (h)bsd2 Mutant
Rubisco content (µmol catalytic sites m−2)9.6 ± 19.3 ± 0.98.1 ± 19.2 ± 0.7NM0.47 ± 0.2
Rubisco activity (µmol CO2 m−2 s−1)31.3 ± 626.3 ± 626.7 ± 631.0 ± 2NM1.08
PEPC activity (µmol CO2 m−2 s−1)165.1 ± 30151.5 ± 17135.1 ± 2150.7 ± 9NM141.25
NADP-ME activity (µmol CO2 m−2 s−1)74.4 ± 585.8 ± 871.8 ± 9108.6 ± 6*NM54.86
PEPC:Rubisco5.8 ± 25.0 ± 15.4 ± 14.6 ± 0.6NM130.6
NADP-ME:Rubisco2.8 ± 0.72.7 ± 0.32.8 ± 0.33.3 ± 0.05NM50.7
Rubisco activation status75.5 ± 492.0 ± 1172.7 ± 1884.4 ± 4NMNM
Stomatal conductance0.319 ± 0.0030.233 ± 0.0090.366 ± 0.020.212 ± 0.010.167 ± 0.007NM