They appear somewhat bashfully for the first time in European art history in the early modern period, right on the edge of a market stall that the Dutch painter Pieter Aertsen (1509-1575) probably painted in 1567. A market woman proudly presents grapes and cabbages, small cucumbers and apples, with a magnificent cauliflower in the center. However, it is easy to miss the three, perhaps four, clearly orange carrots, slightly cut off, on the right edge of the painting. Who would have thought back then that Germany alone – fifth in the world rankings – would produce almost a million tonnes of these vegetable plants in 2021? Cauliflower, on the other hand, is currently at a distant 127,000 tonnes.
A marginal phenomenon for a long time: the orange carrot.
(Photo: Gemäldegalerie, Berlin State Museums/Painting Gallery, Staatliche Musee)
The success story of the carrot may also be one of its color. Originally white in the Mediterranean region, yellow and red-violet in Afghanistan, the most widespread signal orange forms today were probably bred by farmers in the Netherlands, as the painters testify. But only now has a team led by plant scientists Massimo Iorizzo and Kevin Coe from North Carolina State University decoded the genetic causes behind these color pigments. Like the researchers in the specialist magazine Nature Plants report that three specific genes are responsible for the color of carrots. However, surprisingly, these must be recessive, so to speak: switched off.
“Usually you need genes to be switched on for them to perform a function,” says Massimo Iorizzo in a statement from NC State University about the new one NatureStudy: “In the case of the orange carrot, the genes that regulate orange carotenoids – the precursor to vitamin A that has been shown to be beneficial to health – must be switched off.”
NC State scientists have been researching the history and domestication of the carrot for years in collaboration with colleagues at the University of Wisconsin-Madison. In total, they sequenced the genomes of 630 plant species. In 2016, the working group published the first carrot genome ever.
There are surprisingly few carrots to be found in modern art galleries and museums today
In the previous studies, the researchers carried out structural analyzes on five different groups of carrots in order to find, among other things, those areas of the genome that are important for the sensory quality of the root. For example, genes that delay the flowering process have proven to be important, because flowering causes carrots to become woody and inedible. What few people know: If you let carrots grow in peace during their natural, two-year growth cycle, the above-ground flower stalks grow up to 1.50 meters tall.
The new data can also be used to better reconstruct the domestication history of the carrot. They confirm that it was first domesticated in Western and Central Asia in the ninth and tenth centuries. Modern orange carrots are thought to come from a cross between white and yellow roots. Their sweet taste and possibly also the attractive color led to their spread in Western Europe from the 15th or 16th century. In the 16th and 17th centuries, additional types were bred, as can still be seen today in relevant pictures in the picture galleries: Shades of orange.
It was only in the late 19th and early 20th centuries that nutritional physiologists realized that orange carrots also contain a particularly large amount of the carotenoids that were later named after them, as well as relatively high proportions of vitamin C, potassium and iron. Carrots are therefore particularly important in the diet of babies and small children as well as in dietary cuisine in general. Depictions of carrots are now rarely found in modern art galleries.