Carrot confidential: Scientists reveal vegetable's genetic blueprint
Scientists have crunched more than 400 megabytes of data to produce the first near-complete genetic blueprint of the carrot.
Using DNA extracted from one "Nantes" variety carrot, they identified a total of 32,113 genes, including 10,530 unique to the vegetable.
One, known as DCAR_032551, is thought to regulate levels of the orange beta-carotene pigment that gives the carrot its colour and is converted to vitamin A in the body.
Although carrots are a famously rich source of beta-carotene, the way they accumulate the pigment in their roots is still not well understood.
Early domesticated carrots dating back around 1,100 years were reportedly yellow and purple.
Orange-coloured carrots were not reliably documented until the 16th century in Europe. Their popularity proved "fortuitous" because the pigment helps to combat vitamin A deficiency, said the scientists whose work is reported in the journal Nature Genetics.
Pinpointing the origins of beta-carotene in the carrot could pave the way to improving the nutritional quality of other plants, they added.
The team, led by Dr Philipp Simon, from the University of Wisconsin-Madison in the US, wrote: "These results provide the foundation for new genetic mechanisms regulating carotene accumulation in plants, with potential application to several crops."
The carrot, Daucus carota, belongs to the same large family of plants as lettuce and celery.
Comparing the carrot genome to those of other plants enabled the scientists to trace the vegetable's evolutionary journey through time.
They found that the carrot diverged from the potato and tomato around 90.5 million years ago, from the kiwi fruit 101 million years ago, and from the grape 113 million years ago.
In addition to the "generic" carrot genome, the researchers also sequenced DNA from 35 different wild and cultivated specimens and sub-species to shed light on domestication patterns.
The carrot genome would assist the identification of other candidate genes behind "healthy" plant compounds such as flavonoids, as well as mechanisms involved in stress resistance, growth, flowering, seed production and regeneration, said the scientists.
All these properties were said to be "important traits for sustained agricultural production and improved human health".