Abstract
Anthocyanins and betacyanins, two types of red pigment, have never been found to occur together in plants. Although anthocyanins are widely distributed in higher plants, betacyanins have replaced anthocyanins in the Caryophyllales. The accumulation of flavonols in the Caryophyllales suggests that the step(s) of anthocyanin biosynthesis from dihydroflavonols to anthocyanins could be blocked in the Caryophyllales. So far, anthoacyanidin synthase (ANS) cDNA was isolated from plants of the Caryophyllales and an enzyme activity assay showed that the Caryophyllales possess functional ANS. However, the expression profile revealed that ANS are not expressed in most tissues and organs except the seeds in Spinacia oleracea, suggesting the transcriptional regulation might cause the lack of anthocyanin in the Caryophyllales. Therefore, we are trying to reveal the transcriptioal mechanics of ANS from two aspects of their regulatory elements, cis and trans.
We first analyzed the expression of Caryophyllales ANS in Arabidopsis transformed with ANS promoter::GUS constructs. Furthermore, we have tried to find transcription factors which activte Spinacia ANS promoter.
