Genetic Secrets of the Pink Tomato

REHOVOT, IsraelResearchers at the Weizmann Institutes Plant Sciences Department have traced the secret of the pink tomato to a mutation on a single gene known as SIMYB12, which acts as a master switch that regulates the activities of a whole network of other genes, controlling the amounts of yellow pigments as well as a host of other substances in the tomato.

Researchers identified about 400 genes whose activity levels are quite a bit higher or lower in the mutant tomatoes. The largest changes, appearing in both the plant cuticle and the fruit covering, were in the production of substances in the flavonoid family. The pink tomato also has less lycopene, a red pigment known to be a strong antioxidant thats been shown to be associated with reduced risk of cancer, heart disease and diabetes. In addition, alterations in the fatty composition of the pink tomatos outer layer caused its cuticle to be both thinner and less flexible that a regular tomato skin.

Since identifying the gene, we found we could use it as a marker to predict the future color of the fruit in the very early stages of development, even before the plant has flowered. This ability could accelerate efforts to develop new, exotic tomato varieties, a process that can generally take over 10 years, wrote the lead researcher.