Molecular Characterization of the Gene for Dihydroflavonol 4-Reductase of Japonica Rice Varieties
Molecular Characterization of the Gene for Dihydroflavonol 4-Reductase of Japonica Rice Varieties
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粳稻品种二氢黄酮醇4-还原酶基因的分子特性
DOI：
10.5511/plantbiotechnology.15.221
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发表时间：
1998
影响因子：
1.6
通讯作者：
S. Iida
中科院分区：
文献类型：
--
作者：
K. Nakai;Y. Inagaki;H. Nagata;Chikara Miykzaki;S. Iida
花青素是高等植物中最重要的色素。花青素生物合成的基因可分为两类：编码生物合成途径中的酶的结构基因和作用于结构基因的调控基因[1-3]。Dfr基因编码二氢黄酮醇4-还原酶，该酶催化二氢黄酮醇立体定向还原为相应的亮氨酸花青素。双子叶植物的DFR基因由6个外显子和5个内含子组成，而单子叶植物大麦和玉米的DFR基因由4个外显子和3个内含子组成(图1)。最近，一个水稻品种的DFR基因被报道由三个外显子和两个内含子组成。有趣的是，内含子和外显子的位置在这些植物中保存得很好。虽然大多数水稻品种的叶片和茎是绿色的，但也有一些品种的叶片和茎是紫色的，这是由于花青素的着色[5]。作为鉴定水稻花青素生物合成基因的第一步，我们对水稻品种村崎骏(紫稻)的DFR基因进行了鉴定，发现它携带一个由三个外显子和两个外显子组成的DFR基因拷贝
Anthocyanins are the most important pigments in higher plants. Genes for anthocyanin biosynthesis can be classified into two groups; structural genes encoding enzymes in the biosynthesis pathway and regulatory genes acting on the structural genes [1-3]. The DFR gene encodes the enzyme, dihydroflavonol 4 -reductase , which catalyses the stereospecific reduction of dihydroflavonols to the respective leucoanthocyanidines. The DFR genes of dicotyledonous plants consist of six exons and five introns whereas those of monocotyledonous plants barley and maize are comprised of four exons and three introns (Fig. 1). Recently, the DFR gene of a indica variety of rice was reported to consist of three exons and two introns [4] . Interestingly, the positions of the introns and exons are well conserved in these plants. Although most of japonica and indica rice varieties bear green leaves and stems, there are varieties with purple leaves and stems due to anthocyanin pigmentation [5]. As an initial step to characterize genes for anthocyanin biosynthesis in rice, we have characterized the DFR gene of a japonica variety Murasaki-ine (purple rice) and shown that it carries a single copy of the DFR gene consisting of three exons and two