中文摘要：

黄酮醇合成酶（flavonol synthase,FLS）是类黄酮合成分支路口重要的节点酶。FLS基因的表达不仅影响着黄酮醇合成,也影响着花青素苷积累和花色呈现。本研究采用PCR技术从葡萄风信子‘白丽人’中克隆到一条FLS基因（MaFLS1）。序列分析表明,MaFLS1cDNA全长1 152bp,编码383个氨基酸。同源比对及进化分析表明,MaFLS1属于2-酮戊二酸与Fe^＋2依赖型双加氧酶蛋白,具有典型的FLS蛋白功能域、DHQ底物特异结合位点、Fe^2＋和2-酮戊二酸绑定位点;MaFLS1与海枣、油棕的FLS同源性最高,可达74%~75%,与拟南芥、矮牵牛等模式植物亲缘关系较远。荧光定量PCR分析发现,MaFLS1基因在葡萄风信子中为非组织特异性表达模式,其根中表达量最高,鳞茎及花中的表达量其次,叶片中表达量最低;MaFLS1在3个不同花色的葡萄风信子品种5个不同花发育时期表达差异显著,在白色品种‘白丽人’花发育的早期（S1和S2）时期表达较高,粉色品种‘粉日出’和蓝色品种‘亚美尼亚’晚期（S3和S4）表达量最高。本研究为进一步探讨葡萄风信子FLS基因在花色呈现中的功能及黄酮醇支路的分流竞争对花色的影响提供基因资源和依据。

英文摘要：

Flavonol synthase （FLS） is a key node enzyme in flavonol synthesis pathway. The expression of FLS gene affects the syntheses of flavonol,anthocyanin and flower color. In this study, we cloned one FLS gene （designated as MaFLS1） from one white cultivar of grape hyacinth ＇White Beauty＇, using the PCR technique. The full length eDNA of MaFLS1 was 1 152 bp,which coded a 383-amino-acid protein. MaFLS1 belonged to the 2-oxoglutarate iron-dependent oxygenase family, it had FLS functional domains, the residues binded with the DHQ substrate, ferrous iron and 2-oxoglutarate was similar with other FLSs. MaFLS1 shared 74%--75% identity with date palm and oil palm, showing the distant relationship with model plants, like Arabidopsis and Petunia. Expression analysis indicated that MaFLS1 expresses in roots, blubs,leaves,and flowers,with particularly high expression in roots and low expression in leaves. Expression analysis during five different floral developmental stages in three different cultivars showed significant differences. MaFLS1 had the highest expression at stage 2 in ＇White Beauty＇, stage 3 in ＇Pink Surprise＇ and stage 4 in Muscari armeniacum. This research would provide theoretical supports for functional study of MaFLS1 gene,and competition between different branches of the flavonoid pathway in grape hyacinth.