Mdm-miR858 targets MdMYB9 and MdMYBPA1 to participate anthocyanin biosynthesis in red-fleshed apple
Mdm-miR858 targets MdMYB9 and MdMYBPA1 to participate anthocyanin biosynthesis in red-fleshed apple
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DOI：
10.1111/tpj.16111
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发表时间：
2023-02-02
期刊：
影响因子：
7.2
通讯作者：
Wang，Nan
中科院分区：
文献类型：
--
作者：
Li，Zhiqiang;Liu，Wenjun;Wang，Nan
花青素是植物重要的次生代谢产物。它们对人类健康很重要，因为它们具有抗氧化活性，而且从饮食中摄入它们可以减少心脑血管疾病和肿瘤的发病率。水果和蔬菜中花青素的生物合成及其调控是全球研究的热点。与人工栽培的苹果相比，红瓤苹果在市场上是一种相对较新的、受欢迎的商品。以往对红果肉苹果的研究主要集中在高花青素含量和花青素合成的转录调控基础上。在本研究中，我们主要研究了microRNA介导的红肉苹果花青素合成的转录后调控机制。我们鉴定了一个microRNA (miRNA)，命名为mdm‐miR858，它在苹果果肉中特异性表达。miR858在红肉苹果中的表达量显著低于白肉苹果。在STTM858转基因苹果愈伤组织中，过表达mdm‐miR858可显著抑制花青素的积累，而沉默mdm‐miR858可促进花青素的合成。进一步分析表明，mdm‐miR858靶向转录因子mdmyb9和mdmybpa1参与苹果花青素积累。我们的研究结果还表明，光信号通路中的转录因子MdHY5可以结合mdm - miR858的启动子抑制其转录，从而调节花青素的合成。基于我们的研究结果，我们描述了一个新的参与花青素生物合成调节的HY5‐miR858‐MYB环。这些发现为植物mirna如何调控花青素合成代谢提供了新的信息，并为培育富含花青素的红肉苹果新品种提供了基础。
Anthocyanins are important secondary metabolites in plants. They are important for human health because of their antioxidant activities and because their dietary intake reduces the incidence of cardiovascular and cerebrovascular diseases and tumors. The biosynthesis of anthocyanins and its regulation in fruits and vegetables is a global research hotspot. Compared with cultivated apples, the red‐fleshed apple is a relatively new and popular commodity in the market. Previous studies on red‐fleshed apples have focused on the basis for the high anthocyanin content and the transcriptional regulation of anthocyanin synthesis. In the present study, we focused on the mechanism of microRNA‐mediated post‐transcriptional regulation of anthocyanin synthesis in red‐fleshed apples. We identified a microRNA (miRNA), designated mdm‐miR858, that is specifically expressed in the flesh of apple fruit. The expression level of miR858 was significantly lower in red‐fleshed apples than in white‐fleshed apples. The overexpression of mdm‐miR858 significantly inhibited anthocyanin accumulation, whereas the silencing of mdm‐miR858 promoted anthocyanin synthesis in STTM858 transgenic apple calli. Further analyses showed that mdm‐miR858 targets the transcription factor genesMdMYB9andMdMYBPA1to participate anthocyanin accumulation in apple. Our results also show that MdHY5, a transcription factor in the light signaling pathway, can bind to the promoter of mdm‐miR858 to inhibit its transcription, thereby regulating anthocyanin synthesis. Based on our results, we describe a novel HY5‐miR858‐MYB loop involved in the modulation of anthocyanin biosynthesis. These findings provide new information about how plant miRNAs regulate anthocyanin anabolism and provide a basis for breeding new anthocyanin‐rich, red‐fleshed apple varieties.