关键词: 苹果属, 观赏海棠, UFGT, 矢车菊色素苷, 花色素苷

Abstract: More attention has been paid to the utilities of ornamental crabapple for landscape use，because all kinds of color in leaves，flowers and fruits. Anthocyanins are a class of secondary metabolites which contribute to the coloration in higher plants，and also play a vital role in enhancing plant resistance and attracting pollinators. In phenylpropanes metabolism，UFGT（uridine diphosphate glucose flavonoid 3-O-glucosyltransferase）is a key enzyme in anthocyanins biosynthesis pathway. Using the total RNA from the leaves of Malus‘Royalty’（ever-red leaf）as the template，the cDNA of McUFGT（2 186 bp）was cloned by reverse transcription polymerase chain reaction（PCR）and rapid-amplification of cDNA end（RACE）. The gene was named as McUFGT，containing an open reading frame（1 425 bp）and encoding a protein of 475 amino acids. The expression of McUFGT and the content of anthocyanins and flavonoids was determined by real-time quantitative PCR and HPLC in the leaves of Malus‘Royalty’ （ever-red leaf），Malus‘Radiant’（red young leaf and green mature leaf），Malus‘Flame’（ever-green leaf）. Here we report that the cyanidin is the major of anthocyanins in different crabapple cultivars. The results showed that with the development of leaves，there is a significant difference exists in cyanidin contents among these three crabapple cultivars，and the accumulation of cyanidin in‘Royalty’is higher than other two cultivars. At the same time，the content of cyanidin was correlated to the expression level of McUFGT. It is supposed that McUFGT plays an important role in anthocyanins accumulation in different crabapple cultivars.

Key words: Malus, crabapple, UFGT, cyanidin, anthocyanin