IbERF71, withIbMYB340andIbbHLH2, coregulates anthocyanin accumulation by binding to theIbANS1promoter in purple-fleshed sweet potato (Ipomoea batatasL.)
IbERF71, withIbMYB340andIbbHLH2, coregulates anthocyanin accumulation by binding to theIbANS1promoter in purple-fleshed sweet potato (Ipomoea batatasL.)
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IbERF71 与 IbMYB340 和 IbbHLH2 一起通过与紫肉甘薯 (Ipomoea batatas L.) 中的 IbANS1 启动子结合来共同调节花青素积累
DOI：
10.1007/s00299-020-02621-0
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发表时间：
2020-10-21
影响因子：
6.2
通讯作者：
Zhang, Hua
中科院分区：
文献类型：
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作者：
Ning, Zhiyuan;Hu, Kangdi;Zhang, Hua
转录因子IbERF 71形成一个新的复合物IbERF 71-IbMYB 340-IbbHLH 2，通过与紫肉甘薯IbANS 1启动子结合来共同调节花青素苷的生物合成。紫肉甘薯（Ipomoea batatasL.）花色苷是一种具有多种生理功能的天然色素，因其含量丰富而倍受青睐。已经在许多植物中鉴定出参与调控花青素苷生物合成的转铁蛋白。然而，紫肉甘薯花色素苷生物合成的分子机制却很少被研究。本研究通过生物信息学和RT-qPCR技术对TFIbERF 71及其配偶体进行了筛选。结果表明，IbERF 71及其伴侣IbMYB 340和IbbHLH 2在紫肉甘薯中的表达量高于其他颜色甘薯，且表达量与花色苷含量呈正相关。瞬时表达实验表明IbMYB 340 + IbbHLH 2共转化导致了烟草叶片和草莓花托中花青素的积累，另外IbERF 71显著增加了视觉外观。此外，三种转铁蛋白的组合显著提高了草莓花托花青素合成和转运相关基因FvAN和FvGST的表达水平。双荧光素酶报告系统证实，三种转录因子共转化可增强IbANS 1的转录活性。此外，酵母双杂交和萤火虫荧光素酶互补实验表明，IbMYB 340与IbbHLH 2和IbERF 71相互作用，而IbERF 71与IbbHLH 2不相互作用。总之，我们的研究结果提供了新的证据，IbERF 71和IbMYB 340-IbbHLH 2形成的调节复合物IbERF 71-IbMYB 340-IbbHLH 2，通过结合到紫肉甘薯中的IbANS 1启动子来共调节花青素的积累。因此，本研究提供了一个新的调控网络的花青素的生物合成和强大的洞察紫肉甘薯的颜色发展。
Key message The transcription factor (TF)IbERF71forms a novel complex,IbERF71-IbMYB340-IbbHLH2, to coregulate anthocyanin biosynthesis by binding to theIbANS1promoter in purple-fleshed sweet potatoes. Purple-fleshed sweet potato (Ipomoea batatasL.) is very popular because of its abundant anthocyanins, which are natural pigments with multiple physiological functions. TFs involved in regulating anthocyanin biosynthesis have been identified in many plants. However, the molecular mechanism of anthocyanin biosynthesis in purple-fleshed sweet potatoes has rarely been examined. In this study, TFIbERF71and its partners were screened by bioinformatics and RT-qPCR analysis. The results showed that the expression levels ofIbERF71and partnersIbMYB340andIbbHLH2were higher in purple-fleshed sweet potatoes than in other colors and that the expression levels positively correlated with anthocyanin contents. Moreover, transient expression assays showed that cotransformation ofIbMYB340+IbbHLH2resulted in anthocyanin accumulation in tobacco leaves and strawberry receptacles, and additionalIbERF71significantly increased visual aspects. Furthermore, the combination of the three TFs significantly increased the expression levels ofFvANSandFvGST, which are involved in anthocyanin biosynthesis and transport of strawberry receptacles. The dual-luciferase reporter system verified that cotransformation of the three TFs enhanced the transcription activity ofIbANS1.In addition, yeast two-hybrid and firefly luciferase complementation assays revealed that IbMYB340 interacted with IbbHLH2 and IbERF71 but IbERF71 could not interact with IbbHLH2 in vitro. In summary, our findings provide novel evidence that IbERF71 and IbMYB340-IbbHLH2 form the regulatory complex IbERF71-IbMYB340-IbbHLH2 that coregulates anthocyanin accumulation by binding to theIbANS1promoter in purple-fleshed sweet potatoes. Thus, the present study provides a new regulatory network of anthocyanin biosynthesis and strong insight into the color development of purple-fleshed sweet potatoes.