cDNA cloning and characterization of UDP-glucose: anthocyanidin 3-O-glucosyltransferase in Freesia hybrida
cDNA cloning and characterization of UDP-glucose: anthocyanidin 3-O-glucosyltransferase in Freesia hybrida
复制标题
小苍兰 UDP-葡萄糖：花青素 3-O-葡萄糖基转移酶的 cDNA 克隆和表征
DOI：
10.1007/s00299-011-1029-7
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发表时间：
2011-07-01
影响因子：
6.2
通讯作者：
Wang, Li
中科院分区：
文献类型：
--
作者：
Sui, Xin;Gao, Xiang;Wang, Li
在天然化合物的生物合成中，催化形成第一个稳定的花青素的酶是UDP-葡萄糖：花青素3-O-葡萄糖基转移酶(UF3GT)。从小苍兰中分离到一个编码UF3GT的cDNA克隆(Fh3GT1)。系统进化树分析表明，Fh3GT1是糖基转移酶的新成员，属于单子叶亚群。半定量RT-PCR法检测到Fh3GT1在杂交小苍兰不同器官和不同颜色的小苍兰品种花瓣中均有表达，在花瓣完全开放时表达水平最高。酶活性测定结果表明，Fh3GT1在花色苷的体外生物合成中具有一定的作用。为了阐明Fh3GT1的功能，构建了RNA干扰载体Fh3GT1i，并通过农杆菌介导法将其导入矮牵牛。经聚合酶链式反应和Southern杂交证实Fh3GT1已整合到矮牵牛基因组中。SQRT-PCR结果表明，与野生型相比，转基因株系的内源Ph3GT1基因表达水平降低。转基因矮牵牛总花色素色素含量也随着mRNA转录水平的降低而降低，转基因矮牵牛的花色发生了显著变化。综上所述，本工作从小苍兰中克隆了一个UF3GT基因，并证明了一种通过重定向花青素生物合成来改变植物花色的方法。
The enzyme that catalyzes the formation of the first stable anthocyanin in the biosynthesis of natural compounds is UDP-glucose: anthocyanidin 3-O-glucosyltransferase (UF3GT). A cDNA clone (Fh3GT1) encoding UF3GT was isolated from Freesia hybrida. Phylogenetic tree analysis indicated that Fh3GT1 was a novel member of glycosyltransferase, which was classified into monocot subgroups. Semi-quantitative RT-PCR analysis detected transcripts of Fh3GT1 in different organs of F. hybrida and in petals of Freesia cultivars of different colors, and the expression level reached the maximum at the fully opened stage of petals. Characterization of the enzymatic assays indicated that Fh3GT1 had a role in anthocyanin glycoside biosyntheses in vitro. To elucidate the function of Fh3GT1, RNA interference vector (pART-Fh3GT1i) was constructed, and introduced into Petunia grandiflora by Agrobacterium-mediated transformation. Integration of the Fh3GT1 in petunia genome was confirmed by PCR and Southern blotting. SqRT-PCR revealed that the endogenous Ph3GT1 mRNA expression levels decreased in transgenic lines compared with the wild-type. The content of total anthocyanin pigments also decreased with the reduction of mRNA transcript levels, and the transgenic petunia plants had significant changes on their flower colors. In summary, this work identified a UF3GT gene from Freesia hybrida and demonstrated a method to modify plant flower color by redirecting the anthocyanin biosynthesis.