β-Carotene accumulation induced by the cauliflower Or gene is not due to an increased capacity of biosynthesis

The cauliflower Or gene induces a high level of β-carotene accumulation in callus cultures, showing the orange phenotype found in the Or mutant plant. An inhibition study revealed that the increased carotenoid accumulation in the Or calli does not result from an enhanced capacity of carotenoid biosynthesis.