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 - 1.47

USING FUNCTIONAL GENOMICS TOOLS TO EXPLOIT STILBENS AND FLAVONOIDS PATHWAYS OF GRAPEVINE

P. GATTO*^,**, J. MUTH**, D. PRUEFER**, L. ZULINI*, C. MOSER*, M. S. GRANDO*, F. MATTIVI*, R. VELASCO*

*) Istituto Agrario San Michele all’Adige (IASMA), 38010 San Michele all’Adige, Italy

**) Fraunhofer Institut (IME) fuer Molekularbiologie und angewandte Oekologie, 52074 Aachen, Germany

grapevine, resveratrol, phenolic compounds, subtracted libraries, gene expression analysis

Grapevine contains many phenolic substances, most of which originate in the berry. These compounds, which include the phenolics acids, trihydroxy stilbenes and flavonoids, have a number of important oenological functions: they affect the tastes of bitterness and astringency of the wine, determine its colour, especially of the red wine, and they are the key wine preservative and the basis of long aging. In the last years a new interest has surfaced regarding to the natural antioxidant properties of phenols which seem to have beneficial effects against cancer and protective effects on the cardiovascular system. Among these phenolic substances, a hydroxylated stilben, known as resveratrol, has attracted much interest because relatively high quantities are found in grapes and wine, which are considered to be the most important dietary sources of this compounds. Besides the beneficial health effects, resveratrol is known to present an important antifungal feature which may be of interest in wine production technology: resveratrol is a phytoalexin produced by grape in response to microbial attack by the grapevine pathogen Botrytis cinerea. In order to get new information about the factor regulating the synthesis of phenolic compounds in grape, with particular attention to resveratrol, gene expression analysis will be carried out with array technologies. Starting point was the isolation of high quality total RNA from three different grapevine tissues (Vitis vinifera): leaf, root (cv. Pinot noir) and berry (a mix of four cultivars characterized by different resveratrol content: cv. Pinot noir, Teroldego, Friburg, Moscato bianco). The corresponding cDNAs were subjected to cDNA subtraction in order to be enriched for tissue specific differentially expressed genes. The subtracted cDNA pools were then cloned and about 10000 clones of each library picked into 384-well microtiterplates to generate three tissue-specific libraries. The inserts of 4000 clones of each library were then amplified. Next step will be the arraying of the PCR products on Nylon filters, which will be used first to investigate the expression of genes involved in the grape defense mechanisms against grey mould (B. cinerea). For this aim, the cDNA arrays will be hybridized with cDNA probes from healthy and infected leaves, collected at different time points, of two grape cultivars, Friburg and Teroldego, which are resistant and susceptible to the disease. Further hybridizations aiming to the identification of genes regulating the synthesis of phenolic compounds under different conditions such as in developing grape berries, will be performed. The expression profiles derived by array hybridisations will be compared with biochemical analysis of resveratrol and other phenolic compounds content in selected cultivars under different agronomic conditions. The coupling of genomic analysis and biochemical approaches will lead to a better knowledge of the biosynthetic pathways of grape phenols, which could be exploited for commercial applications.