Genetic mechanisms of pigment accumulation in carrot colours

Authors: Simon, Philipp

Submitted to: Open Access Government
Publication Type: Literature Review
Publication Acceptance Date: 6/2/2023
Publication Date: 6/12/2023
Citation: Simon, P.W. 2023. Genetic mechanisms of pigment accumulation in carrot colours . Open Access Government. https://doi.org.10.56367/OAG-039-10810.
DOI: https://doi.org/10.56367/OAG-039-10810

Interpretive Summary: Orange carrots are familiar to consumers around the world, but were only first described around 500 years ago. Purple and yellow were the first colors of carrots during its domestication history, reported 1100 years ago. The pigments responsible for carrot colors are carotenoids, for orange, yellow, and red carrots, and anthocyanins, for purple carrots. The vibrant colors of carrots are an important visual cue to stimulate consumer interest which has important positive nutritional consequences. Most important of these are the orange carotenoids which are sources of vitamin A while red, yellow, and purple pigments also provide key nutrients as antioxidants contributing to eye health and to reduced incidence of cardiovascular disease and certain forms of cancer. Carrot colors have also attracted an interest in the scientific research community as they provide insights into the historical development and domestication of carrot as a root crop, they provide a foundation for a better understanding of the molecular and biochemical mechanisms underlying carotenoid and anthocyanin biosynthesis. The sequencing of the carrot genome is a significant stimulus in providing insights in the development of high-pigment carrots and this story is only beginning to unfold.

Technical Abstract: Most consumers in the Western world today are only familiar with orange carrots, and while orange is the color of most carrots grown globally today, red carrots are widely grown in Asia. Furthermore, the predominant color of carrots was not always orange. In fact, yellow and purple were the original colors of carrots in Central Asia (especially Afghanistan) over 1000 years ago, where carrots were likely first widely grown as a root crop. Through genetic analysis of carrot we identified a gene controlling carotenoid accumulation in the carrot root that is an important domestication trait, the foundation to the orange color of modern carrots, and a model for the discovery of regulatory mechanisms underlying carotenoid accumulation in plants. This review tracks that history and recent progress in understanding the colors of carrots.