Table 2.
Balance sheet showing the fates of EA supplied to transgenic tobacco plants expressing spinach PEAMT
| Metabolites | −EA, μmol per plant | +EA, μmol per plant | Difference,* μmol per plant |
|---|---|---|---|
| EA | 0.7 | 14.5 | +13.8 |
| Monomethylethanolamine | 3.3 | 2.4 | −0.9 |
| Cho | 20.6 | 34.1 | +13.5 |
| Phosphoethanolamine | 1.6 | 2.6 | +1.0 |
| Phosphomonomethylethanolamine | 12.1 | 9.6 | −2.5 |
| Phosphocholine | 1.5 | 2.7 | +1.2 |
| Phosphatidylethanolamine | 2.6 | 3.4 | +0.8 |
| Phosphatidylmonomethylethanolamine | 0.7 | 1.3 | +0.6 |
| Phosphatidylcholine | 4.2 | 5.3 | +1.1 |
| GlyBet | 1.0 | 1.6 | +0.6 |
| Totals | 48.3 | 77.5 | +29.2 |
| EA lost from medium† | 100 | ||
Individual plants were cultured for 4 weeks on 50 ml of medium with or without 5 mM EA; the EA dose was thus 250 μmol per plant. Each plant then was harvested and assayed for EA metabolites, and the quantity of EA left in the medium was determined. Data are means for duplicate plants. Dimethylethanolamine and its esters were undetectable.
*
Metabolite level in the +EA treatment minus that in the −EA treatment.
†
EA loss from the medium after incubation for 4 weeks with no plant present was insignificant.