关键词: 柑橘, 类黄酮, 查尔酮合成酶, 多态性, 差异表达

Abstract: Chalcone synthase is one of the most important enzymes in flavonoids biosynthesis pathway. In this study，the CHS genes encoding chalcone synthase were isolated from 10 citrus species. Their expressions in different parts of plant and different time of the development were analysed by qRT-PCR. The flavonoids content at different development stages of fruits and leaves were investigated. The results indicated that in different citrus species，the CHS genes are very conservative with a high level of similarity at 98%. However，polymorphism on amino acid sequence of CHS was found among different citrus species，which demonstrated certain relationship with flavonoids content. The study reveals that expression level of CHS genes significantly different among different species，part of plant and development stages，indicating the CHS gene plays an important role in the biosynthesis of flavonoids in citrus.

Key words: citrus, flavonoids, chalcone synthase, polymorphism, differential expression