CINNAMIC ACID 4-HYDROXYLASE

摘要

After-cooking darkening is a gray-black discoloration of the potato tuber, formed after cooking by the oxidation of an iron-chlorogenic acid complex. Cinnamic acid 4-hydroxylase (C4H) is a key enzyme involved in the biosynthesis of chlorogenic acid. The full-length c4h gene was cloned and sequenced from both genomic DNA and cDNA of Russet Burbank tuber tissue by PCR and 5' and 3' RACE. The gene expression levels of c4h were examined by Northern hybridization in potato cultivars varying in susceptibility to after-cooking darkening. Results suggest that there is a relationship between the levels of c4h gene expression and the degree of after-cooking darkening in potato tubers.