The first dedicated step in plant xanthophyll biosynthesis is carotenoid hydroxylation. In Arabidopsis thaliana, this reaction is performed by both heme (LUT1 and LUT5) and non-heme (CHY1 and CHY2) hydroxylases. No mutant completely abolishing α- or β-carotene hydroxylation has been described to date. We constructed double and triple mutant combinations in CHY1, CHY2, LUT1, LUT5 and LUT2 (lycopene epsilon-cyclase). In chy1chy2lut2, 80% of leaf carotenoids is represented by β-carotene. In chy1chy2lut5, β-carotene hydroxylation is completely abolished, while hydroxylation of the β-ring of α-carotene is still observed. The data are consistent with a role of LUT5 in β-ring hydroxylation, and with the existence of an additional hydroxylase, acting on the β-ring of α-, but not β-carotene. © 2006.
All Science Journal Classification (ASJC) codes
- Structural Biology
- Molecular Biology
- Cell Biology
Fiore, A., Dall'Osto, L., Fraser, P. D., Bassi, R., & Giuliano, G. (2006). Elucidation of the β-carotene hydroxylation pathway in Arabidopsis thaliana. FEBS Letters, 580(19), 4718 - 4722. https://doi.org/10.1016/j.febslet.2006.07.055