We're bored to tears with ordinary green limes. Fortunately, we don't have to suffer much longer. New, transgenic limes are on the horizon, taking their hues from blood oranges and red seedless grapes.
Credit: Manjul Dutt
The Journal of the American Society for Horticultural Science has published the first pictures of transgenic Mexican limes (above). Developed by researchers at the University of Florida, these limes have an abundance of anthocyanins, responsible for a lot of pigmentation in foliage. They contribute to fall leaf colours, red cabbages, and black berries. Some scientists believe that they may be a plant's response to environmental stressors like drought or cold temperatures — and the citrus fruits known as "blood oranges" only develop anthocyanins after being exposed to cold during their growth.
It's the genes of the Moro, or blood, orange that are responsible for the pink colour in the center lime pictured above. The darker lime on the left has genes from the the red seedless grape. The plants themselves also show some pigmentation in both the young leaves — which have a reddish cast which fades over time — and the flowers.
Right now, their beauty is all they have to offer; these are ornamental plants. Although the genes come from other food plants, and anthocyanins are associated with health benefits, the researchers want to test these transgenic limes before they're offered as food. If successful, researchers might try the same trick with oranges and other fruit grown in tropical and subtropical climates — to give us more variety at the store, and more anthocyanins in our diet.