Gene that gives carrots their colour identified

HEALTHY PICK:Carrots are loaded with beta-carotene that the body can transform into Vitamin A.— Photo: AFP

HEALTHY PICK:Carrots are loaded with beta-carotene that the body can transform into Vitamin A.— Photo: AFP  

Scientists unveiled on Monday the gene in carrots that gives rise to carotenoids, a critical source of Vitamin A and the pigment that turns some fruits and vegetables bright orange or red.

Un-poetically dubbed ‘DCAR_032551’, the star gene emerged from the first complete decoding of the carrot genome, published in the scientific journal Nature Genetics .

“Vitamin A deficiency is a global health challenge,” the study pointed out.

“Its plentiful carotenoids make carrot an important source of provitamin A in the human diet.”

Carotenoids were first discovered in carrots (hence the name), but which among the vegetable’s newly tallied 32,115 genes was most responsible for their formation remained a mystery. The researchers sequenced the genome of a bright orange variety of the vegetable called the Nantes carrot, named for the French city.

Daucus carota now joins a select club of about a dozen veggies — including the potato, cucumber, tomato and pepper — whose complete genomes have been sequenced.

Laying bare the humble carrot’s genetic secrets will make it easier to enhance disease resistance and nutritive value in other species, the researchers said.

Having identified the mechanism controlling the accumulation of carotenoid, it may be possible — through gene-editing, for example — to import it to other staple root vegetables such as the cassava, native to South American and widely grown in Africa. “These results will facilitate biological discovery and crop improvement in carrots and other crops,” said Philipp Simon, senior author and a professor at the University of Wisconsin-Madison.

Among vegetables spinach and peas are widely associated with growing up strong, but it’s hard to beat the carrot when it comes to health boosters.

Carrots are loaded with beta-carotene, a natural chemical that the body can transform into Vitamin A.

The deeper the orange colour, the more beta-carotene.

Carotenoids are also antioxidants, which are thought to protect against heart disease and some forms of cancer by neutralising so-called “free radicals”, single oxygen atoms that can damage cells.

“Some of these compounds can prevent disease,” Mr. Simon said.

“Carrots are an interesting crop to work on because of their wide range of diversity. They are familiar to everyone, and generally well-regarded by consumers, but like most familiar things, people don’t necessarily know the background stories,” said Mr. Simon, led the study published in the journal Nature Genetics .

Interestingly, carrots — along with many other plants — have about 20 per cent more genes than humans.

Looking back at the plant’s family tree, scientists have been able to determine that it split with the grape about 113 million years ago and from the kiwi about 10 million years after that, when dinosaurs still lorded over the planet.

Originally white, the wild ancestors of the carrot likely came from central Asia. The earliest record of carrots as a root crop dates from 1,100 years ago in Afghanistan, but those were yellow carrots and purple ones, not orange ones. Paintings from 16th century Spain and Germany provide the first unmistakable evidence for orange carrots. Global crop production of the root has quadrupled in the last 40 years and is today eaten everywhere in the world. — AFP/Reuters

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