Table 1.
Growth parameters and leaf characteristics of wild-type and low PsbO plants
Wild-type plants all have greater than 0.9 µmol m–2 functional PSII centres and plants with low PsbO have less than 0.6 µmol m–2 functional PSII centres. Average relative growth rate (RGR) over the course of the growth experiment was calculated by fitting an exponential to the data points of each individual plant. Initial surface area refers to that at the start of growth measurements (10 days after transfer from sucrose-supplemented growth media to soil) and final surface area that after a further 12 days (i.e. 22 days after transfer to soil). LMA, Leaf mass per area; △A, absorbance proportional to P700 content, assuming the 810nm measuring beam path length is constant between samples; Adaxial absorptance, absorptance to the xenon projector lamp used as the actinic source for light response measurements.
| Wild type | Low PsbO | P | |||
| Mean ± SE | n | Mean ± SE | n | ||
| Relative rate of rosette area increase (m2 m–2 day–1) | 0.19±0.00 | 5 | 0.13±0.01 | 7 | <0.0001 |
| Initial surface area (cm2) | 3.29±0.16 | 5 | 2.08±0.38 | 7 | 0.0037 |
| Final surface area (cm2) | 30.81±0.84 | 5 | 9.34±2.55 | 7 | <0.0001 |
| LMA dry (g m–2) | 16.9±1.2 | 5 | 13.4±0.4 | 6 | 0.0130 |
| LMA fresh (g m–2) | 258±18 | 5 | 196±9 | 6 | 0.0101 |
| Leaf dry mass/fresh mass | 0.066±0.001 | 5 | 0.070±0.003 | 6 | 0.1893 |
| Leaf thickness of fixed sections (µm) | 214±19 | 3 | 154±10 | 3 | 0.04808 |
| Leaf transverse cell layers | 8.42±0.22 | 3 | 7.50±0.52 | 3 | 0.1802 |
| Grana per chloroplast | 34.5±2.0 | 3 | 28.8±0.7 | 3 | 0.0562 |
| Thylakoid layers per grana | 4.87±0.14 | 3 | 5.66±0.17 | 3 | 0.0236 |
| Chl a (µmol m–2) | 309±9 | 9 | 156±8 | 8 | <0.0001 |
| Chl b (µmol m–2) | 79±2 | 9 | 51±3 | 8 | <0.0001 |
| Chl a/b | 3.9±0.1 | 9 | 3.1±0.1 | 8 | <0.0001 |
| ∆A max (absorbance units × 103) | 4.3±0.2 | 6 | 2.5±0.2 | 7 | 0.0001 |
| Adaxial absorptance | 0.76±0.01 | 7 | 0.73±0.01 | 9 | 0.0216 |