MdMYB1 Regulates Anthocyanin and Malate Accumulation by Directly Facilitating Their Transport into Vacuoles in Apples
MdMYB1 Regulates Anthocyanin and Malate Accumulation by Directly Facilitating Their Transport into Vacuoles in Apples
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MdMYB1 通过直接促进花青素和苹果酸转运至苹果液泡中来调节花青素和苹果酸的积累
DOI：
10.1104/pp.15.01333
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发表时间：
2016-03-01
期刊：
影响因子：
7.4
通讯作者：
Hao, Yu-Jin
中科院分区：
文献类型：
--
作者：
Hu, Da-Gang;Sun, Cui-Hui;Hao, Yu-Jin
液泡膜转运体，包括质子泵和次生转运体，对于植物细胞功能和肉质果实和观赏植物的优质形成是必不可少的。花青素、苹果酸和其他代谢产物的液泡运输直接或间接依赖于液泡H+-ATPase(VHA)和/或液泡H+-焦磷酸酶的H+泵活性，但这些质子泵是如何调节液泡运输的在很大程度上是未知的。在这里，我们报道了苹果中的一个转录因子MdMYB1，它与编码VHA B亚基的两个基因的启动子结合，通过转录激活其表达，从而增强VHA的活性。对苹果的一系列转基因分析表明，MdMYB1/10部分通过调节MdVHA-B1和MdVHA-B2来控制细胞pH和花青素的积累。此外，还鉴定了MdMYB10的其他几个直接靶基因，包括MdVHA-E2、MdVHP1、MdMATE-like 1和MdtDT，它们参与了H+泵或花青素和苹果酸向液泡的运输。最后，我们证明了MYB控制苹果中苹果酸和花青素积累的机制也在拟南芥中起作用。这些发现为MYB转录因子如何直接调节液泡运输系统以及花青素的生物合成，从而控制植物的器官着色和细胞pH提供了新的见解。
Tonoplast transporters, including proton pumps and secondary transporters, are essential for plant cell function and for quality formation of fleshy fruits and ornamentals. Vacuolar transport of anthocyanins, malate, and other metabolites is directly or indirectly dependent on the H+-pumping activities of vacuolar H+-ATPase (VHA) and/or vacuolar H+-pyrophosphatase, but how these proton pumps are regulated in modulating vacuolar transport is largely unknown. Here, we report a transcription factor, MdMYB1, in apples that binds to the promoters of two genes encoding the B subunits of VHA, MdVHA-B1 and MdVHA-B2, to transcriptionally activate its expression, thereby enhancing VHA activity. A series of transgenic analyses in apples demonstrates that MdMYB1/10 controls cell pH and anthocyanin accumulation partially by regulating MdVHA-B1 and MdVHA-B2. Furthermore, several other direct target genes of MdMYB10 are identified, including MdVHA-E2, MdVHP1, MdMATE-LIKE1, and MdtDT, which are involved in H+-pumping or in the transport of anthocyanins and malates into vacuoles. Finally, we show that the mechanism by which MYB controls malate and anthocyanin accumulation in apples also operates in Arabidopsis (Arabidopsis thaliana). These findings provide novel insights into how MYB transcription factors directly modulate the vacuolar transport system in addition to anthocyanin biosynthesis, consequently controlling organ coloration and cell pH in plants.