The genes responsible for the orange color in carrots have finally been discovered, giving biologists a deeper understanding of their nutritional value.
The earliest cultivated carrots in the 10th century were purple or yellow. It wasn’t until the 1400s in western Europe that orange carrots appeared, possibly resulting from the hybridization of yellow and white carrots.
Since then, orange carrots have become popular due to their vibrant color and sweet taste. In the early 1900s, it was recognized that orange carrot juice had medicinal properties, contributing to carrots’ reputation as a healthy vegetable.
Researchers, led by Massimo Iorizzo at North Carolina State University, have now unraveled the science behind the distinct orange color of carrots. They conducted genome sequencing on 630 carrot varieties and identified gene variants associated with specific traits.
Three genes were found in orange carrots where the variants resulted in the genes being deactivated. In purple, yellow, or white carrots, at least one of these three genes remained active.
These genes regulate the levels of alpha-carotene and beta-carotene, which are carotenoids responsible for the orange pigment in carrots. These carotenoids are converted into vitamin A in the human body, crucial for eye health, the immune system, and other bodily functions.
When these genes are switched off, carrots produce more of these pigments, giving them their distinctive orange color and making them a rich source of vitamin A. Other carrot varieties have higher levels of different carotenoids that do not convert into vitamin A.
Furthermore, many orange carrots also possess gene variants that delay flowering, resulting in a tougher and inedible crop. It turns out that farmers have unintentionally selected these desirable traits for centuries.
Iorizzo and his team believe that a comprehensive understanding of carrot genetics can lead to the development of even better carrots in the future.
