In a recent study published in the journal Horticulture Research, researchers from Nanjing Agricultural University have shed light on the gene DcCYP97A3, which controls the carotenoid content and colour of carrots.
Through genetic editing and overexpression experiments, the study revealed how this gene influences the conversion of α-carotene into lutein, altering the colour of carrot taproots from orange to yellow and impacting the overall carotenoid content.
Carrots are rich in carotenoids, which are essential for human health and also provide important compounds such as vitamin A.
The colour of carrot taproots varies according to the types and levels of carotenoids, including α-carotene, β-carotene and lutein.
The DcCYP97A3 gene is a key player in this process, as it catalyses the conversion of α-carotene to lutein, a vital xanthophyll.
However, the role of this gene in regulating carotenoid biosynthesis across carrot varieties had remained unclear — until now.
The research focused on two carrot varieties, Kurodagosun (KRD) (orange) and Yellowstone (YST) (yellow), comparing their carotenoid profiles and expression levels of the DcCYP97A3 gene.
The scientists found that the YST variety had higher levels of DcCYP97A3 transcripts, resulting in a greater accumulation of lutein and reduced α-carotene levels.
By overexpressing the DcCYP97A3 gene from YST into the orange KRD carrot, the researchers observed a significant shift in carotenoid content, with lutein content increasing and α-carotene decreasing.
This shift was further confirmed by gene editing in YST carrots, which showed a reduction in lutein and β-carotene when DcCYP97A3 was knocked out.
These findings underscore the role of DcCYP97A3 in shaping carotenoid diversity in carrots, offering insights into how genetic modifications could enhance the nutritional profile of crops.
Dr Ai-Sheng Xiong, a senior researcher involved in the study, commented: "Our findings provide a clearer understanding of how specific genes such as DcCYP97A3 influence carotenoid content, which is critical not only for the colour of carrots but also for their nutritional value."
"This research could lead to the development of carrot varieties with higher nutritional content, catering to the growing demand for healthy food options.”
The implications of this study are significant for both agriculture and nutrition.
By manipulating the DcCYP97A3 gene, it may be possible to breed carrots with optimised carotenoid profiles, making them more beneficial for human health.
Moreover, these findings can be applied to other crops where carotenoid accumulation affects colour and nutritional quality.
The research lays the groundwork for future genetic studies aimed at improving vegetable breeding strategies and increasing the nutritional value of staple crops globally.