Anthocyanin Formation in the Petals of Hibiscus mutabilis L.

Abstract

When opening in the morning flowers of Hibiscus mutabilis L. appear white or ivory. The flower colour changes to red by late afternoon due to the accumulation of the anthocyanin cyanidin-3-sambubioside. At the onset, and during the rapid phase of pigment accumulation, phenylalanine ammonia-lyase (PAL) activity in the petals increases rapidly to seven times its initial level and then decreases while the flower senesces. In excised petals, the PAL inhibitor L-a-aminooxy-P-phenylpropionic acid (AOPP) suppresses pigment formation and causes the accumulation of phenylalanine. Anthocyanin synthesis depends, therefore, on the de novo production of cinnamic acid. © 1989, Walter de Gruyter. All rights reserved.