Overexpression of a bacterial 1-deoxy-D-xylulose 5-phosphate synthase gene in potato tubers perturbs the isoprenoid metabolic network : implications for the control of the tuber life cycle

Potato tubers were engineered to express a bacterial gene encoding 1-deoxy-D-xylulose 5-phosphate synthase (DXS) in order to investigate the effects of perturbation of isoprenoid biosynthesis. Twenty-four independent transgenic lines out of 38 generated produced tubers with significantly elongated s...

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Veröffentlicht in:Journal of experimental botany. - 1985. - 57(2006), 12 vom: 15., Seite 3007-18
1. Verfasser: Morris, Wayne L (VerfasserIn)
Weitere Verfasser: Ducreux, Laurence J M, Hedden, Peter, Millam, Steve, Taylor, Mark A
Format: Aufsatz
Sprache:English
Veröffentlicht: 2006
Zugriff auf das übergeordnete Werk:Journal of experimental botany
Schlagworte:Journal Article Research Support, Non-U.S. Gov't Bacterial Proteins Cytokinins Gibberellins Plant Growth Regulators Plant Proteins Terpenes Carotenoids 36-88-4 mehr... Abscisic Acid 72S9A8J5GW Oxidoreductases EC 1.- phytoene dehydrogenase EC 1.14.99.- Transferases EC 2.- deoxyxylulose-5-phosphate synthase EC 2.2.1.- Alkyl and Aryl Transferases EC 2.5.- Geranylgeranyl-Diphosphate Geranylgeranyltransferase EC 2.5.1.32
Beschreibung
Zusammenfassung:Potato tubers were engineered to express a bacterial gene encoding 1-deoxy-D-xylulose 5-phosphate synthase (DXS) in order to investigate the effects of perturbation of isoprenoid biosynthesis. Twenty-four independent transgenic lines out of 38 generated produced tubers with significantly elongated shape that also exhibited an early tuber sprouting phenotype. Expression analysis of nine transgenic lines (four exhibiting the phenotype and five showing a wild-type phenotype) demonstrated that the phenotype was strongly associated with dxs expression. At harvest, apical bud growth had already commenced in dxs-expressing tubers whereas in control lines no bud growth was evident until dormancy was released after 56-70 d of storage. The initial phase of bud growth in dxs tubers was followed by a lag period of approximately 56 d, before further elongation of the developing sprouts could be detected. Thus dxs expression results in the separation of distinct phases in the dormancy and sprouting processes. In order to account for the sprouting phenotype, the levels of plastid-derived isoprenoid growth regulators were measured in transgenic and control tubers. The major difference measured was an increase in the level of trans-zeatin riboside in tubers at harvest expressing dxs. Additionally, compared with controls, in some dxs-expressing lines, tuber carotenoid content increased approximately 2-fold, with most of the increase accounted for by a 6-7-fold increase in phytoene
Beschreibung:Date Completed 08.12.2006
Date Revised 10.03.2022
published: Print-Electronic
Citation Status MEDLINE
ISSN:1460-2431