| Abstract Detail
Secondary Metabolism - Afternoon Diretto, Gianfranco [1], Tavazza, Raffaela [1], Al-Babili, Salim [2], Welsch, Ralf [2], Pizzichini, Daniele [1], Papacchioli, Velia [1], Morgues, Fabienne [3], Puglia, Giuseppe [1], Beyer, Peter [2], Giuliano, Giovanni [1]. Metabolic Engineering Of Beta-Carotene In Potato (S. Tuberosum L.) Tubers. CAROTENOIDS are a class of pigments which are essential for photosynthesis and metabolic functions. Animals do not produce carotenoids and therefore they must get them by a nutrient supplementation; these molecules are fundamental for human health: beta-carotene is, in fact, the dietary precursor of vitamin A and other dietary carotenoids like lycopene and zeaxanthin have preventive effects on age-related illnesses, such as prostate cancer or eye macular degeneration. In order to increase beta-beta-carotenoid content, we produced transgenic plants with the antisense fragment of lycopene epsilon-cyclase (e-lcy) cloned between the tuber-specific Patatin promoter and the Nos terminator. Transgenic tubers were characterized through HPLC analysis which revealed in different lines, an increase of 3-14 fold of ß carotene and important modifications of xanthophyll content. Real-time PCR proved endogenous e-lcy gene silencing as well as perturbations of transcript levels of CrtIso and b-lcy which were overexpressed in transgenic tubers. No alterations were observed in tuber yield, leaf chlorophyll and carotenoid contents as well as leaf transcript levels of endogenous genes. In a different approach, we transformed potato plants with erwinia uredovora genes, encoding for phytoene synthase (CrtB), phytoene desaturase (CrtI) and lycopene cyclase (CrtY) introduced in sense orientation under the control of constitutive (CAMV 35S) or tuber-specific (Patatin) promoter. Spectrophotometric analyses revealed, in several transgenic lines, increases up to 40 fold in total carotenoids. Further analyses (HPLC, real-time pcr) are in progress to characterize these transgenic plants and to identify genes which are regulated by carotenoid levels. References - Giuliano, G., Aquilani, R. and Dharmapuri, S. (2000) Metabolic engineering of plant carotenoids. Trends Plant Sci 5 (10), 406-409. - Ducreux L., Morris W., Hedley P., Shepherd T., Davies H., Millam S. and Taylor M. (2004) Metabolic engineering of high carotenoid potato tubers containing enhanced levels of b-carotene and lutein. J. Exp. Bot. 10, 1-9
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1 - Ente per le Nuove tecnologie, l\'Energia e l\'Ambiente (ENEA), Casacci, Biotechnology Unit, Via Anguillarese N.301, PO Box 2400, Rome, 00060, Italy
2 - Albert-Ludwigs University of Freiburg, Center for Applied Biosciences, Schaenzlestr. 1, Freiburg, 79014, Germany
3 - ENEA,Trisaia Research Center, 75026 Rotondella (MT), biotecnology unit, s.s.106, km 419+500 Rotondella (MT), Rotondella (MT), 75026, Italy
Keywords:
beta-carotene
Potato
transgenic.
Session: Poster-66
Location: Ballroom CD/Monona Terrace
Date: Tuesday, July 25th, 2006
Time: 8:00 AM
Abstract ID:203 |
