Characterization of OfWRKY3, a transcription factor that positively regulates the carotenoid cleavage dioxygenase gene OfCCD4 in Osmanthus fragrans
Characterization of OfWRKY3, a transcription factor that positively regulates the carotenoid cleavage dioxygenase gene OfCCD4 in Osmanthus fragrans
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OfWRKY3（一种正调节桂花中类胡萝卜素裂解双加氧酶基因 OfCCD4 的转录因子）的表征
DOI：
10.1007/s11103-016-0483-6
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发表时间：
2016-07-01
影响因子：
5.1
通讯作者：
Shang, Fude
中科院分区：
文献类型：
--
作者：
Han, Yuanji;Wu, Miao;Shang, Fude
桂花类胡萝卜素裂解双加氧酶4（OfCCD 4）裂解类胡萝卜素如β-胡萝卜素和玉米黄质以产生β-紫罗兰酮。OfCCD 4是CCD基因家族的成员，其启动子含有一个W盒回文序列和两个TGAC重复序列，这两个重复序列是WRKY转录因子的结合位点。我们从桂花花瓣中分离到三个WRKY基因。其中之一，OfWRKY 3，编码含有两个WRKY结构域和两个锌指基序的蛋白质。OfWRKY 3和OfCCD 4在“丹桂”和“银桂”不同花期的花瓣中的表达谱几乎相同，在水杨酸、茉莉酸和脱落酸处理的花瓣中的表达谱也相似。在共渗透的烟草叶中检测到OfWRKY 3对OfCCD 4（pro）：GUS的激活，并且在对照组织中检测到非常弱的GUS活性，表明OfWRKY 3可以与OfCCD 4启动子相互作用。酵母单杂交和电泳迁移率变动分析表明，OfWRKY 3能够结合到OfCCD 4启动子中存在的W-box回文基序。这些结果表明，OfWRKY 3是OfCCD 4基因的正调控因子，并可能部分解释桂花中β-紫罗兰酮的生物合成。
The sweet osmanthus carotenoid cleavage dioxygenase 4 (OfCCD4) cleaves carotenoids such as beta-carotene and zeaxanthin to yield beta-ionone. OfCCD4 is a member of the CCD gene family, and its promoter contains a W-box palindrome with two reversely oriented TGAC repeats, which are the proposed binding sites of WRKY transcription factors. We isolated three WRKY cDNAs from the petal of Osmanthus fragrans. One of them, OfWRKY3, encodes a protein containing two WRKY domains and two zinc finger motifs. OfWRKY3 and OfCCD4 had nearly identical expression profile in petals of 'Dangui' and 'Yingui' at different flowering stages and showed similar expression patterns in petals treated by salicylic acid, jasmonic acid and abscisic acid. Activation of OfCCD4(pro):GUS by OfWRKY3 was detected in coinfiltrated tobacco leaves and very weak GUS activity was detected in control tissues, indicating that OfWRKY3 can interact with the OfCCD4 promoter. Yeast one-hybrid and electrophoretic mobility shift assay showed that OfWRKY3 was able to bind to the W-box palindrome motif present in the OfCCD4 promoter. These results suggest that OfWRKY3 is a positive regulator of the OfCCD4 gene, and might partly account for the biosynthesis of beta-ionone in sweet osmanthus.