Chalcone synthase (CHS) catalyzes the committed enzymatic step in flavonoid biosynthesis. In parsley (Petroselinum crispum), CHS is encoded by a single gene locus. Transcriptional activation of the gene in response to UV-containing white light has been demonstrated. Analysis of the CHS gene promoter by in vivo footprinting revealed four short sequences, designated Boxes I, II, III, and IV, whic...
