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

Giardini Naxos, Italy - 18/21 September, 2002

ISBN 88-900622-3-1

Poster Abstract - 2.03

SUNFLOWER SUSPENSION CULTURES FOR THE BIOTECHNOLOGICAL PRODUCTION OF VITAMIN E

FACHECHI C., GALA R., D’AMICO L., CARETTO S.

Istituto di Scienze delle Produzioni Alimentari – CNR , Sezione di Lecce, Via Monteroni, 73100 Lecce, Italy

Vitamin E, in vitro production, tocopherol biosynthesis, sunflower

Essential micronutrients in the human diet include several vitamins known to promote clear benefits to human health. Tocopherols (vitamin E) are a class of lipid-soluble antioxidants synthesized only by photosynthetic organisms. Epidemiological studies indicate that vitamin E dietary supplementation results in decreased risk for cardiovascular disease and cancer, and prevents or slows a number of degenerative diseases associated with aging. Tocopherols can be produced by chemical synthesis, but racemic mixtures which are less efficacious than the natural isomers are obtained. Plant cell cultures have proven to be successful tools for the production of specific metabolites, such as natural food ingredients. Nevertheless, they represent powerful tools for investigating the metabolic pathways of these molecules.

We started an in vitro system for the production of a-tocopherol by means of sunflower cell cultures. Optimal growth conditions were established and several green suspension cultures were obtained and analysed for their growth ability and tocopherol yields. Here the characterization of some sunflower suspension cultures has been carried out: high variability in the tocopherol biosynthetic capability (up to 3-fold differences) was observed between the cultures. The analysis of the tocopherol isoforms (a, b, g and d) showed that the differences were due to the a-form, which was more than 90% of the total tocopherols in all the analysed cultures. On the other hand, the growth curves of such cultures were always very similar. The effects of feeding the cultures with tocopherol precursors like homogentisic acid and phytol have been also investigated. The results suggest that the administration of these molecules only increased the tocopherol yields of the cultures characterised by high levels of tocopherol production.