关键词: 菊花, 花青素苷, 基因表达, 花色表型, 白花突变体

Abstract: To illustrate the effect of expression patterns of structural and regulatory genes on anthocyanin biosynthesis in chrysanthemum（Chrysanthemum × morifolium Ramat.），we took a single flower cut chrysanthemum‘Pink’（‘DF-3’）and its white flower mutant（‘MD’）as materials. HPLC analysis results showed that ray florets of the pink cut chrysanthemum cultivars‘DF-3’containing two cyanidin glycosides derivatives，cyanidin 3-O-（6"-O-monomalonyl-β-glucopyranoside）and cyanidin 3-O-（3"，6"- O-dimalonyl-β-glucopyranoside），while no anthocyanin was detected in that of the mutant‘MD’. Semi-quantitative RT-PCR results showed that，CHI，F3H，F3'H with similar expression patterns，expressed in the LⅠstage，increased with the development of inflorescence，and peaked at HⅡstage，then decreased gradually. However，there was little expression signal of CHS，DFR and ANS at bud stage，but peaked at HⅡ，then decreased gradually. ANS and DFR were floral tissue-specific genes. Regulatory genes WD40 and bHLH were strongly expressed in the LⅢ stage before the structural genes expression，and MYB was not expressed at the bud stage，then began to express at HⅠstage，and peaked at HⅢ stage. The expressions of all structural genes were reduced at various developmental stages in white flower mutant（‘MD’）than wild type（‘DF-3’）. In‘MD’，there was very weak expression of F3H and ANS，and no expression of DFR. Expression of bHLH was very weak，and expression of WD40 and MYB had a slight decrease than in wild type. These results indicated that the expression of key structural genes，such as CHS，CHI，F3H，F3'H，DFR，and ANS resulted in the accumulation of cyanidin in ray florets of chrysanthemum. While the mechanism of reduced expression of regulatory genes MYB and bHLH in white flower mutant（‘MD’）may be closely related with the formation of the white flower.

Key words: Chrysanthemum ×, morifolium；anthocyanin biosynthesis；gene expression；color phenotype；white mutant