Table II. Quantification of mesophyll cell size and layers.
Measurements were taken from hand-cut cross sections of fully expanded adult leaves of different leaf widths. Leaf thickness represents the mean of three measurements taken at three points across the mediolateral axis: at a vein, directly adjacent to a vein, and midway between two veins. To cover the normal range seen in the wild type (WT), leaves with widths between 9 and 13 mm were chosen for measurements. Mesophyll cell sizes represent means of six cell size measurements in one leaf. For cell number between veins, measurements were taken between three or four pairs of intermediate veins for each leaf. Values represent means ± se. Significance was tested using a one-way ANOVA. There was a significantly lower number of mesophyll cell layers between line 20730 and the wild type (***, P < 0.0005) and between line 20731 and the wild type (*, P < 0.05). Leaf thickness, mesophyll cell size, and mesophyll cell number between veins were not significantly different between transgenic lines and the wild type.
| Line | Leaf Width | Leaf Thickness | No. of Mesophyll Cell Layers | Mesophyll Cell Size | Mesophyll Cell No. between Veins |
|---|---|---|---|---|---|
| mm | µm | µm2 | |||
| WT1a | 11 | 91.7 ± 4.3 | 6 | 240.5 ± 35.3 | 8–9 |
| WT1b | 11 | 94.3 ± 5.0 | 5 | 186. 33 ± 45.8 | 8–9 |
| WT1c | 11 | 88.3 ± 2.8 | 5 | 172.7 ± 46 | 8 |
| WT2a | 12 | 88.7 ± 8.8 | 6 | 218.3 ± 20.5 | 7–8 |
| WT2b | 12 | 91 ± 1.0 | 6 | 205.7 ± 30.2 | 7–9 |
| WT2c | 12 | 82 ± 2.6 | 5 | 210.5 ± 25.1 | 7 |
| WT3a | 13 | 85.6 ± 5.6 | 6 | 251.8 ± 33.9 | 7–9 |
| WT3b | 13 | 82.6 ± 2.6 | 5 | 241.8 ± 32.9 | 7–9 |
| WT3c | 13 | 76 ± 5.1 | 5 | 195.3 ± 30.1 | 7–9 |
| WT4a | 10 | 79.7 ± 4.9 | 4 | 205.2 ± 12.4 | 8 |
| WT4b | 10 | 80.7 ± 4.1 | 4 | 229.8 ± 30.9 | 7 |
| WT4c | 10 | 80 ± 5.1 | 3 | 190.7 ± 20.2 | 8 |
| WT5a | 9 | 77.5 ± 4.3 | 4 | 205.8 ± 23.3 | 8 |
| WT5b | 9 | 82 ± 6.0 | 4 | 197.5 ± 37 | 8 |
| WT5c | 9 | 69.3 ± 9.2 | 3 | 172.8 ± 37.2 | 7 |
| WT total | 83.3 ± 1.7 | 4.7 ± 0.3 | 205.3 ± 6.1 | 7–9 | |
| 207_29-1a | 9 | 71.7 ± 6.0 | 5 | 131.2 ± 34.3 | 11 |
| 207_29-1b | 9 | 67 ± 4.0 | 4 | 186.5 ± 43.2 | 8 |
| 207_29-1c | 9 | 78 ± 2.1 | 5 | 229.7 ± 63.7 | 7 |
| 207_29-2a | 10 | 91 ± 7.5 | 4 | 233.3 ± 58.8 | 7 |
| 207_29-2b | 10 | 77 ± 7.1 | 4 | 191.2 ± 16.5 | 7 |
| 207_29-2c | 10 | 74.3 ± 9.7 | 4 | 185.7 ± 41 | 9 |
| 207_29-3a | 12 | 84.7 ± 12.3 | 4 | 224.2 ± 29.9 | 8–9 |
| 207_29-3b | 12 | 90.3 ± 11.8 | 4 | 200.3 ± 40.3 | 8 |
| 207_29-3c | 12 | 84.7 ± 12.9 | 3 | 209 ± 27.9 | 7 |
| 207_29 total | 79.9 ± 2.8 | 4.1 ± 0.2 | 199 ± 10.4 | 7–11 | |
| 207_30-1a | 10 | 78 ± 4.2 | 3 | 261 ± 44.9 | 6–8 |
| 207_30-1b | 10 | 81.3 ± 3.7 | 3 | 188.8 ± 26.3 | 8 |
| 207_30-1c | 10 | 85 ± 5.7 | 3 | 220 ± 48.5 | 7 |
| 207_30-2a | 11 | 79 ± 3.1 | 3 | 200.4 ± 30.6 | 6 |
| 207_30-2b | 11 | 88.3 ± 7.5 | 3 | 210.5 ± 51.8 | 7 |
| 207_30-2c | 11 | 78.7 ± 9.9 | 3 | 251.3 ± 39.8 | 6 |
| 207_30 total | 81.7 ± 1.7 | 3 ± 0*** | 222 ± 11.7 | 6–8 | |
| 207_31-1a | 10 | 80 ± 9.1 | 4 | 158 ± 40.3 | 9 |
| 207_31-1b | 10 | 81.7 ± 4.1 | 4 | 227.3 ± 51.7 | 7 |
| 207_31-1c | 10 | 81.7 ± 3.5 | 3 | 147 ± 10.9 | 8 |
| 207_31-2a | 11.5 | 84.3 ± 3.2 | 4 | 271.7 ± 27.8 | 8 |
| 207_31-2b | 11.5 | 79.7 ± 3.9 | 4 | 230.3 ± 22.5 | 7 |
| 207_31-2c | 11.5 | 74.3 ± 5.2 | 3 | 198.2 ± 28.8 | 8 |
| 207_31 total | 80.3 ± 1.4 | 3.6 ± 0.2* | 205.4 ± 19.3 | 7–9 |