Proceedings of the XLVII Italian Society of Agricultural Genetics - SIGA Annual Congress

Verona, Italy - 24/27 September, 2003

ISBN 88-900622-4-X

Poster Abstract - 1.49

PARADOX EFFECTS OF CAROTENOID METABOLIC ENGINEERING IN tomato (Lycopersicon esculentum L.) FRUITS

G. Diretto*, C. Rosati**, P. Pallara**, B. Camara***, G. Giuliano*

*) Ente per le Nuove tecnologie, l'Energia e l'Ambiente (ENEA), Biotechnology Unit, Casaccia Research Centre, PO Box 2400, Roma 00100AD, Italy

**) Ente per le Nuove tecnologie, l'Energia e l'Ambiente (ENEA), Biotechnology Unit, Trisaia Research Centre, 75026 Rotondella (MT), Italy

***) CNRS, Plant Molecular Biology Institute, 67084 Strasbourg Cedex, France

tomato, beta-carotene

Plant carotenoids are 40-carbon isoprenoid compounds involved in many physiological and biochemical functions, such as light harvesting and photoprotection from excess light energy; additionally, they colour many flowers and fruits, probably to attract animals and to protect reproductive structures by high light intensity. Carotenoids also play a crucial role in human health by improving normal vision and by preventing degenerative diseases like cancer. Animals do not produce carotenoids and therefore they must get them by a nutrient supplementation, as for Beta-carotene, the major dietary precursor of vitamin A. In this context we began a metabolic engineering approach on tomato (Lycopersicon esculentum L.) fruits, which, in their wild-type form, contain almost pure lycopene. In this work, the pepper Beta-carotene hydroxylase cDNA, cloned in sense orientation under the control of tomato fruit-specific PDS promoter, was introduced, via Agrobacterium tumefaciens, in tomato plants (cv MoneyMaker) and transformed plants were checked by PCR assay. Phenotypic analyses revealed that, contrary to expectations, the colour of the ripe fruits varied from the complete red of wild-type cv Moneymaker to red-orange to complete orange of several transgenic lines. Further studies are in progress in order to characterize transgenic fruits at the biochemical (by HPLC analyses) and molecular (by Real Time PCR and DNA microarray) levels.

References

- Giuliano, G., Aquilani, R. and Dharmapuri, S. (2000) Metabolic engineering of plant carotenoids. Trends Plant Sci 5 (10), 406-409

- Rosati, C., Aquilani, R., Dharmapuri, S., Pallara, P., Marusic, C., Tavazza, R., Bouvier, F., Camara, B. and Giuliano, G. (2000) Metabolic engineering of beta-carotene and lycopene content in tomato fruit. Plant J 24 (3), 413-419

- Hirschberg, J. (2001) Carotenoid biosynthesis in flowering plants. Curr Opin in Plant Biol 4, 210-218

- Dharmapuri S., Rosati C., Pallara P., Aquilani R., Bouvier F., Camara B. and Giuliano G. (2002) Metabolic engineering of xanthophyll content in tomato fruits. FEBS Lett 519, 30-34.