Over-expression of Arabidopsis thaliana carotenoid hydroxylases individually and in combination with a β-carotene ketolase provides insight into in vivo functions

Hydroxylation of carotenoid β- and ε-rings is critical for their modification to generate a diversity of carotenoids, including ketocarotenoids. Assay of carotenoid profiles in multiple Arabidopsis thaliana lines overexpressing four carotenoid hydroxylases alone or in combination with an algal β-carotenoid ketolase provides insight into in vivo enzyme functions and pathway cross-talk.