Betalains are a group of water-soluble natural pigments found only in plants of the order Caryophyllales, including the red-purple betalains and the yellow-brown betalains. Recent studies have found that betalains also have many health functions such as antibacterial, anticancer, anti-inflammatory, hypolipidemic and neuroprotective. However, the limited natural sources of betalains have limited their development and application.

 

Carrot is an important root vegetable crop widely cultivated worldwide, which is highly adaptable and productive, and is an ideal recipient for genetic transformation. The synthesis of betalains in carrots helps to improve their nutritional quality on the one hand, and on the other hand, their fleshy roots, above-ground parts or residues after processing can be used for betalains extraction to increase their economic value.

 

This study demonstrates that synthetic biology techniques can reconstruct the betalains biosynthesis pathway in carrots, providing theoretical and technical support for cultivating new carrot germplasm with high betalains content and expanding the biological sources of betalains.