USING ANTISENSE RNA TO STUDY GENE-FUNCTION - INHIBITION OF CAROTENOID BIOSYNTHESIS IN TRANSGENIC TOMATOES

Transgenic tomato plants expressing antisense RNA to a ripening related gene (pTOM5) have yellow ripening fruit and pale colored flowers. The yellow fruit color is correlated with a severe reduction in the level of the pTOM5 gene mRNA during fruit ripening. The level of carotenoids in ripening fruit from selected transgenic plants showing yellow fruit was reduced by more than 97 percent. In addition, the carotenoid lycopene, which is primarily responsible for the red color of ripening fruit, was reduced to undetectable levels (< 0.1%). These data indicate that the pTOM5 gene is crucial to tomato fruit carotenoid biosynthesis.