Abstract
Two types of red pigments, anthocyanins and betacyanins, never occur together in the same plant. 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. We have shown that the Caryophyllales had genes encoding functional DFR and ANS and the genes are not expressed in most tissues and organs in Spinacia oleracea.
To clarify the regulatory mechanism of DFR and ANS expression, we have analyzed promoter region of DFR and ANS in the Caryophyllales. The promoter region contains several motifs, which a transcriptional factor could bind. Yeast one-hybrid assay showed that PhAN2 and PhJAF13, which were anthocyanin regulators, could bind to the DFR and ANS promoters of spinach. The transient assay in Phytolacca americana cells showed that the promoters were not activated by PhAN2 and PhJAF13.
