Table 3.
Photosynthetic performance of wild type and transgenic plants.
| Wild type | GMK3-1 | GMK3-3 | |
|---|---|---|---|
| CO2 assimilation rate, A (μmol m−2 s−1) | 11.5 ± 0.28 | 12.0 ± 0.46 | 10.4 ± 0.56 |
| Stomatal conductance (mol m−2 s−1) | 0.255 ± 0.043 | 0.247 ± 0.032 | 0.187 ± 0.021 |
| Intercellular CO2, Ci (μbar) | 240 ± 16 | 258 ± 8 | 252 ± 5 |
| Ambient CO2, Ca (μbar) | 347 ± 1.0 | 347 ± 0.6 | 349 ± 0.9 |
| Dark respiration rate, Rd (μmol m−2 s−1) | 1.89 ± 0.14 | 2.09 ± 0.36 | 1.91 ± 0.16 |
| RubisCO (μmol sites/m−2) | 17.66 ± 0.35 | 16.35 ± 1.8 | 13.3 ± 1.0 |
| Chlorophyll (μmol m−2) | 0.42 ± 0.02 | 0.31 ± 0.01 | 0.28 ± 0.09 |
| Chlorophyll a/b ratio | 3.61 ± 0.48 | 3.62 ± 0.105 | 3.68 ± 0.08 |
| Leaf mass per area, LMA (g m−2) | 18.9 ± 0.6 | 16.4 ± 0.4 | 15.4 ± 0.5 |
| A (μmol g−1 s−1) | 0.61 ± 0.03 | 0.74 ± 0.2 | 0.676 ± 0.03 |
| A (mmol mol chl−1 s−1) | 27.6 ± 1.5 | 38.4 ± 2.9 | 37.0 ± 1.7 |
| A [mol (mol RubisCO sites)−1 s−1] | 0.65 ± 0.01 | 0.754 ± 0.06 | 0.79 ± 0.037 |
| CO2 compensation point, Γ at 21% (μbar) | 42.7 ± 0.6 | 43.9 ± 0.9 | 44.2 ± 1.4 |
| Slope of O2 dependence of Γ (mbar/bar) | 0.206 ± 0.02 | 0.212 ± 0.03 | 0.207 ± 0.03 |
| Intercept of O2 dependence of Γ (μbar) | 0.78 ± 0.17 | 0.03 ± 0.14 | 1.05 ± 0.0.54 |
GMK3-1 and GMK3-3 are GMK3 plants of the first and third generation, respectively. Gas exchange measurements were performed as described in the Section “Materials and Methods” at a leaf temperature of 25°C and an irradiance of 1000 μmol quanta m−2 s−1. The values presented are the means ± SE of four replicates. The values set in bold case indicate significant differences to wild type values.