Schematic carotenoid biosynthesis pathways: the alpha- and beta-carotenoid routes to the major metabolites lutein and neoxanthin.
Activity of P450 enzymes (CYP97A3, CYP97B3, CYP97C1), deduced from mutant phenotype analysis, heterologously expressed enzymes or biochemical analysis of over-expression lines are indicated at the pathway step (1Tian et al. (2004); 2Fiore at al. (2006); 3Kim and DellaPenna (2006); 4Kim et al. (2010)). anon-heme β-carotene-ring hydroxylase.