Characterization of acylated anthocyanin and anthocyanin p-coumaroyltransferase in Japanese garden, Iris ensata Thunb

点击翻译按钮获取中文摘要

In this study, acylated anthocyanins and anthocyanin p-coumaroyltransferase of Iris ensata Thunb. were characterized, and the following results were obtained.1. The anthocyanins of 130 cultivars and 13 lines and 3 wild forms were analyzed by HPLC, and these plants were classified into 16 types of major anthocyanins. Among these types, petunidin 3RG5G-malvidin 3RG5G, malvidin 3RG5G-peonidin 3RG5G, peonidin 3RG5G-cyanidin 3RG5G and peonidin 3RG-cyanidm 3RG were obtained new non-acylated types.2. The fading of flower color in acylated anthocyanin type cultivars and non-acylated anthocyanin ones and the in vitro stability of malvidin 3RGac5G, 3RG5G, petunidin 3RGac5G and 3RG5G due to different pH conditions and copigmentation with isovitexin were examined. The acylated anthocyanin cultivars exhibited higher flower color stability than the non-acylated anthocyanin ones. Malvidin 3RGac5G, 3RG5G, petunidin 3RGac5G and 3RG5G were not stable except at the lowest pH 3.2, although the acylated anthocyanins showed slightly more stable than the non-acylated ones.3. Enzyme extracts from flower buds of the acylated anthocyanin cultivar catalyzed in transfer of the p-coumaroyl moiety from p-coumaroyl-CoA to both the anthocyanidins 3RG and 3RG5G. In contrast, anthocyanidin 3G did not serve as acyl acceptors at all. Moreover, anthocyanin p-coumaroyltransferase was controlled by dominant gene, which is symbolized as Ac.