The tomato is perhaps rivalled only by the fire engine for its iconic redness. Carotenoids are the chemical dyes responsible, but different dyes called betalains colour many other plants, fruit and vegetables. The luscious red tomato appears on the left here, unripe at the top and ripe beneath. Scientists genetically engineered another tomato to produce a type of betalain called betacyanin, giving it a deep purple colour (2nd from left). Similar treatment with a yellowish dye (betaxanthin) produced the tommy on the middle right. But this is not just about livening up salads – each of these chemicals has potential health benefits, from antioxidant to anti-inflammatory properties – and the tomato on the right contains all of them. In the future, tomatoes and other plants might act as sources for healthy betalains, which may also make the plants themselves more resistant to diseases.
BPoD stands for Biomedical Picture of the Day. Managed by the MRC Laboratory of Medical Sciences until Jul 2023, it is now run independently by a dedicated team of scientists and writers. The website aims to engage everyone, young and old, in the wonders of biology, and its influence on medicine. The ever-growing archive of more than 4000 research images documents over a decade of progress. Explore the collection and see what you discover. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.
BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.