【摘要】 四季秋海棠(Begonia semperflorens)是重要的园林观赏植物，其花朵成簇开放，花色艳丽。为了研究四季秋海棠花色形成机理，本研究根据前期获得的四季秋海棠转录组数据，克隆花青素合成途径的关键酶UDP-葡萄糖：类黄酮糖基转移酶(UDP-glycose:flavonoid glycosyltransferase, UFGT)基因，通过荧光定量PCR技术检测其在四季秋海棠不同组织中的表达量，并将其转化烟草(Nicotiana tabacum’NC89’)进行功能验证。结果显示，成功克隆了1条cDNA全长为1 536 bp、编码511个氨基酸的基因序列，将其命名为BsUFGT (GenBank No. OL329828)。BsUFGT相对分子量为56 385.34 D，理论等电点(pI)为5.25，含有UDPGT结构域，定位于细胞膜及细胞核中。qRT-PCR分析显示，四季秋海棠花中的BsUFGT表达量显著高于叶和茎的表达量(P<0.05)。转化烟草发现，转基因烟草花冠中的花青素苷含量高于野生型烟草花冠中的花青素苷含量，表明BsUFGT基因能够促进花青素苷的合成和积累，本研究为四季秋海棠花青素苷合成的分子调节机制提供了理论依据。更多还原

【Abstract】 Begonia semperflorens are considered as an important garden ornamental plant, with its flowers open in clusters and gorgeous colors. In order to study the mechanism of the flower color formation of B.semperflorens, in this study, the anthocyanin synthesis pathway key enzyme flavonoid glycosyltransferase gene(UDP-glycose flavonoid glycosyltransferase, UFGT), were cloned and analyzed using B. semperflorens as materials, according to the previous stage of B. semperflorens transcriptome data. Differences in the expression of BsUFGT gene in different tissues of B. semperflorens were detected by fluorescence quantitative PCR and transformed into Nicotiana tabacum ’NC89’ for functional verification. The results showed that a cDNA of 1536 bp and 511 amino acids gene sequence was successfully cloned and named BsUFGT(GenBank No.OL329828). The molecular weight was 56 385.34 D, the theoretical isoelectric point(pI) was 5.25. Domain analysis showed that the UFGT protein encoded by BsUFGT gene had a UDPGT domain. Subcellular localization results showed that BsUFGT was mainly localized in cell membrane and nucleus.The q RT-PCR analysis showed that BsUFGT expression in B. semperflorens flowers was significantly higher than that in leaves and stems(P<0.05). BsUFGT of B. semperflorens were transformed into N. tabacum ’NC89’ for functional verification. The anthocyanin content of anthocyanins in transgenic tobacco corolla was higher than that in wild-type tobacco corolla. This study provides a theoretical basis for the molecular regulation mechanism of anthocyanin synthesis in B. semperflorens.更多还原