Abscisic acid regulation of heterophylly in Marsilea quadrifolia L. : effects of R-(-) and S-(+) isomers
The plant hormone abscisic acid (ABA) induces a developmental switch in the aquatic fern Marsilea quadrifolia, causing the formation of aerial type characteristics, including the elongation of petioles and roots, a change in leaf morphology, the expansion of leaf surface area, and the shortening of...
| Veröffentlicht in: | Journal of experimental botany. - 1985. - 56(2005), 421 vom: 01. Nov., Seite 2935-48 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , |
| Format: | Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2005
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| Zugriff auf das übergeordnete Werk: | Journal of experimental botany |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Plant Growth Regulators Abscisic Acid 72S9A8J5GW |
| Zusammenfassung: | The plant hormone abscisic acid (ABA) induces a developmental switch in the aquatic fern Marsilea quadrifolia, causing the formation of aerial type characteristics, including the elongation of petioles and roots, a change in leaf morphology, the expansion of leaf surface area, and the shortening of the internodes. A number of ABA-responsive heterophylly (ABRH) genes are induced early during the transition. Using optically pure isomers of ABA, it was found that both the natural S-(+)-ABA and the unnatural R-(-)-ABA are capable of inducing a heterophyllous switch and regulating ABRH gene expression. When dose responses are compared, the unnatural ABA gives stronger morphogenic effects than the natural ABA at the same concentration, it is effective at lower concentrations, and its optimal concentration is also lower compared with the natural ABA. Deuterium-labelled ABA enantiomers were used to trace the fate of applied ABA and to distinguish the applied compound and its metabolites from the endogenous counterparts. In tissues, the supplied (+)-ABA was metabolized principally to dihydrophaseic acid, while the supplied (-)-ABA was converted at a slower rate to 7'-hydroxy abscisic acid. Treatment with either enantiomer resulted in increased biosynthesis of ABA, as reflected in the accumulation of endogenous dihydrophaseic acid. Taken together, these results suggest two distinct mechanisms of action for (-)-ABA: either (-)-ABA is intrinsically active, or its activity is due to the stimulation of ABA biosynthesis |
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| Beschreibung: | Date Completed 10.01.2006 Date Revised 10.03.2022 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1460-2431 |