Table 1.
Estimated Cytosolic and Plastidic Concentrations of Metabolites Involved in the Pathway of Suc to Starch
| Metabolite | Attached Tubers | Detached Tubers |
|---|---|---|
| Cytosol | ||
| Suc | 82.4 ± 22.9 | 47.9 ± 4 |
| Fru | 1.37 ± 0.72 | 1.79 ± 0.38 |
| UDP-Glc | 571 ± 17 | 627 ± 54 |
| Glc-1-P | 42.7 ± 13 | 115 ± 79 |
| Glc-6-P | 510 ± 18 | 1212 ± 177 |
| Fru-6-P | 147 ± 12 | 299 ± 85 |
| ATP | 292 ± 9 | 151 ± 39 |
| ADP | 87.3 ± 7 | 77 ± 47 |
| UTP | 238 ± 8 | 121 ± 8 |
| UDP | 52.4 ± 3 | 37.1 ± 4 |
| PPi | 12.0 ± 0.7 | 6.9 ± 2.9 |
| Pi | 2400 ± 1120 | 2200 ± 620 |
| 3PGA | 296 ± 43 | 324 ± 72 |
| Plastid | ||
| Glc-6-P | 379 ± 108 | 822 ± 155 |
| Glc-1-P | 17.4 ± 6.7 | 64 ± 22 |
| ADP-Glc | 21.5 ± 2 | 11.2 ± 1 |
| ATP | 179 ± 7 | 279 ± 31 |
| ADP | 149 ± 14 | 148 ± 27 |
| PPi | 2.36 ± 1.43 | 0.68 ± 0.68 |
| Pi | 870 ± 350 | 500 ± 260 |
| 3PGA | 198 ± 33 | 244 ± 95 |
The cytosolic and plastidic metabolite levels, obtained after nonaqueous fractionation, were divided by the fractional volumes of the cytosolic (0.606 mL/g dry wt) and plastidic compartments (0.747 mL/g dry wt) to derive the respective cytosolic and plastidic concentrations (Farré et al., 2001). Data are means ± se (n = 3) and are expressed in μM, except for Suc and Fruc, which are expressed in mM.