As the weather warms up, a lot of us start thinking about watermelon. Few people know that watermelon is more than a refreshing summer snack. It contains carotenoids, pigments that human health depends on. Our bodies can’t make them, so we get them from fruits and vegetables, and watermelon is one of the richest sources.
A team of Chinese scientists used precision breeding and genetic mapping to pinpoint a gene, named Clpf, that is responsible for pink flesh. A protein linked to it, ClPPR5, regulates how much carotenoid builds up in the flesh.
To see how ClPPR5 affects pigment levels, the researchers compared two watermelons, one with red flesh and one with pink. The pink one had less lycopene, the main carotenoid behind the red color of fruit. It also had fewer chromoplasts, the organelles where carotenoids are stored.
The scientists then moved on to tomatoes, which also accumulate high levels of carotenoids as they ripen. When they silenced the matching gene in tomatoes, carotenoid content dropped. That confirmed the gene controls how much pigment the fruit produces.
The researchers hope breeders can use the results to develop varieties with more carotenoids, which would make watermelons more nutritious.
