Scientists at the Institute of Agricultural Genomics in Shenzhen have made an unexpected discovery: the modern potato appeared about 9 million years ago as a result of hybridization between wild tomatoes and a little-known plant called Etuberosum.
The key was the interaction of two genes: SP6A (inherited from the tomato) and IT1 (contributed by Etuberosum). Each of them on its own is useless for forming tubers, but together they gave the plant the ability to accumulate starch underground — and, in essence, made the potato into a potato.
The above-ground part of the plant still resembles its wild ancestor, but the tubers are an evolutionary innovation. They not only store energy, but also allow the plant to reproduce without seeds, which gave the potato a chance to survive in the harsh conditions of the Andes.
Today, biologists are trying to reverse this trick — by introducing tuber-forming genes into tomatoes. If it works, we will have tomatoes with mini-tubers. Admit it, that is an interesting twist for gardeners.
