Table IV.
13C enrichment studies in 5-week-old mature root tips of FL and mMDH antisense transgenic lines
Root tips were segmented in 5-mm lengths and incubated for 3 and 5 h in [U-13C]Glc. Values are presented as means ± se of six individual plants per line; values in boldface were determined by the t test to be significantly different (P < 0.05) from the wild type. Negligible enrichment is indicated by “nd.”
| Metabolite | Wild Type | mMDH7 | mMDH8 | mMDH21 | FL11 | FL41 | FL63 |
|---|---|---|---|---|---|---|---|
| μmol fractional carbon enrichment g−1 fresh weight h−1 | |||||||
| Ala (×102) | 3.0 ± 1.0 | 5.0 ± 1.0 | 8.0 ± 3.0 | 3.0 ± 1.0 | 5.0 ± 1.0 | 9.0 ± 2.0 | 4.0 ± 1.0 |
| Asp (×102) | 18.0 ± 8.0 | 4.0 ± 2.0 | 23.0 ± 7.0 | 1.0 ± 1.0 | 20.0 ± 10.0 | 5.0 ± 1.0 | 3.0 ± 1.0 |
| Citrate | 31.7 ± 10.3 | 15.6 ± 4.7 | 69.1 ± 21.5 | 7.3 ± 2.7 | 7.5 ± 2.0 | 5.2 ± 2.6 | 26.1 ± 12.6 |
| Fru | 33.1 ± 15.8 | 53.9 ± 18.3 | 40.7 ± 11.2 | 58.4 ± 20.1 | 50.3 ± 16.8 | 20.3 ± 14.4 | 47.0 ± 15.0 |
| Fumarate | 0.7 ± 0.1 | 0.2 ± 0.2 | 1.1 ± 0.6 | 0.2 ± 0.1 | 0.3 ± 0.2 | 0.5 ± 0.1 | 0.2 ± 0.1 |
| Glu (×102) | 329.0 ± 135.0 | 19.0 ± 8.0 | 95.0 ± 33.0 | 20.0 ± 10.0 | 18.0 ± 8.0 | 7.0 ± 2.0 | 3.0 ± 1.0 |
| Malate | 4.7 ± 0.9 | 3.3 ± 1.8 | 8.9 ± 1.6 | 2.6 ± 0.8 | 0.9 ± 0.3 | 0.5 ± 0.2 | 4.0 ± 1.3 |
| Quinate | 2.0 ± 0.7 | 0.8 ± 0.3 | 1.7 ± 0.5 | 1.4 ± 0.9 | 1.3 ± 0.4 | 0.8 ± 0.3 | 0.9 ± 0.2 |
| Ser | 0.5 ± 0.3 | 0.5 ± 0.2 | 0.8 ± 0.4 | 0.2 ± 0.1 | 0.2 ± 0.1 | 0.2 ± 0.2 | 0.1 ± 0.0 |
| Val | 0.7 ± 0.4 | 2.3 ± 1.5 | nd | nd | nd | 0.3 ± 0.2 | 0.1 ± 0.0 |