Characterization of carotene accumulation inUstilago violacea using high-performance liquid chromatography

Abstract

Quantitative analysis of carotene accumulation in white, pink, pumpkin, orange, and yellow haploid strains ofUstilago violacea by high-performance liquid chromatography indicated that specific patterns of carotene accumulation are primarily responsible for the white, pumpkin, orange, and yellow phenotypes. The yellow strains accumulated primarily β-zeacarotene and β-carotene. The white strains accumulated primarily the colorless carotene, phytoene, or did not accumulate any carotene at all. Carotene accumulation in pink haploid strains followed the same patterns as for the white, pumpkin, orange, or yellow strains. Pink diploid and disomic strains ofU. violacea with various parental combinations of the color mutations accumulated either cis-β-zeacarotene and β-carotene or only β-carotene. The pattern of carotene accumulation in conjunction with the available genetic information for the carotene loci inU. violacea was used as a basis for the construction of a new genetic model for carotene biosynthesis inU. violacea. The model employs three dehydrogenases and one cyclase for the synthesis of β-carotene from phytoene, and accounts for the carotene accumulation patterns of either cis-β-zeacarotene and β-carotene or lycopene, γ-carotene, and β-carotene.