The full genome sequence of the carrot is reported in a paper published online this week in Nature Genetics, representing one of the most complete vegetable genome assemblies known to date. The genome sequence sheds light on the evolutionary origin of the carrot, its distinctive orange colour and its nutritious value.
Carrots belong to the same class of plants as lettuce and celery. The genomes of such crops, which are an important component of diets worldwide, have not yet been published.
Philipp Simon and colleagues assembled a high-quality reference genome using the DNA from one carrot, identifying 32,113 genes, with 10,530 genes unique to carrot. They then sequenced 35 different carrot specimens and subspecies, both wild and cultivated, to understand domestication patterns. They compared the carrot sequence to other plant genomes and determined when carrots diverged from grape, kiwi and tomato. Finally, they found a gene responsible for the uncommonly high accumulation of beta-carotene, a vitamin A precursor, in the carrot root.
The authors suggest that this information can be used to help breeders improve the nutritional quality of not only carrots but other diverse crops as well.