Abstract:

To study different structural genes expression pattern in anthocyanin biosynthesis pathway of cineraria with different flower color, internal segments of five structural genes, chalcone synthase (CHS), chalcone isomerase (CHI), flavanone 3-hydroxylase (F3H), flavonoid 3'-hydroxylase (F3'H) and dihydroflavonol 4-reductase (DFR), were isolated from cineraria petals using RT-PCR. Using semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR), the expression patterns of CHS, CHI, F3H, F3'H, DFR, flavonoid 3',5'-hydroxylase (F3'5'H) and anthocyanin 3-O-glucoside-6"-O-malonyltransferase (3MaT) in five developmental stages of cineraria with different flower colors were determined for the first time. The results indicated that there is no CHS transcript in white flowers. In red flowers, F3'H mRNA was expressed at high level. But no F3'5'H transcript was found. F3'5'H was highly expressed in Stage I but no F3'H mRNA was observed in blue flowers. And the transcripts of F3'H and F3'5'H were found in purple petals. In addition, these genes were expressed at high level in early stage and underwent moderate decreases in expression. Interestingly, genes expression level increased again in Stage IV. However, in Stage V, there is little expression level could be detected in petals.

Key words: cineraria, Senecio cruentus, flower color, anthocyanin biosynthesis, gene isolation, gene expression