EXPRESSION OF ANTHOCYANIN BIOSYNTHESIS PATHWAY GENES IN RED AND WHITEGRAPES

The expression of seven genes from the anthocyanin biosynthesis pathwa y was determined in different tissues of Shiraz grapevines. All of the tissues contained proanthocyanidins, but only the berry skin accumula ted anthocyanins. In most tissues, all of the flavonoid genes except U DP glucose-flavonoid 3-o-glucosyl transferase (UFGT) were expressed, b ut UFGT expression was only detected in berry skin. Similar patterns o f expression were observed in the skin of other red grapes. In white g rapes, UFGT expression was not detected. White grape cultivars appear to lack anthocyanins because they lack UFGT, although they also had de creased expression of other flavonoid pathway genes.