MicroRNA828 negatively regulates lignin biosynthesis in stem of Populus tomentosa through MYB targets
MicroRNA828 negatively regulates lignin biosynthesis in stem of Populus tomentosa through MYB targets
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MicroRNA828通过MYB靶标负调控毛白杨茎中的木质素生物合成
DOI：
10.1093/treephys/tpac023
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发表时间：
2022
期刊：
影响因子：
4
通讯作者：
Di Fan
中科院分区：
文献类型：
--
作者：
Xianqiang Wang;Shu Yao;Win Pa Pa Myo Htet;Yuchen Yue;Zhuanzhuan Zhang;Kuan Sun;Sijie Chen;Keming Luo;Di Fan
抽象的。厚壁组织细胞中木质素的生物合成受到一个复杂的遗传和环境信号网络的严格控制。在过去的几十年里，木本植物木质素合成的转录调控已经建立起来。然而，microRNA介导的转录后调控在次生细胞壁生物合成中的作用仍然知之甚少。在这里，我们鉴定了一个microRNA，miR828，参与调控毛白杨茎发育过程中木质素的生物合成。MiR828在茎发育过程中优先在次生维管组织中表达。通过降解组分析和绿色荧光蛋白信号检测，证实两个MYB基因(MYB171和MYB011)是miR828的直接靶点。在杨树中过表达miR828下调了木质素生物合成的基因，导致细胞壁木质素含量减少。相反，通过短串联靶标模拟抑制植物中的miR828可以提高木质素生物合成基因的表达，增加木质素的沉积。我们进一步揭示了杨树MYB171作为茎中含量最丰富的miR828靶标，是木质素生物合成的正调控因子。瞬时表达分析表明，MYB171和MYB011都激活了PAL1和CCR2的转录，而miR828的引入显著抑制了MYB171或MYB011诱导的PAL1和CCR2的表达。综上所述，我们的结果表明miR828-MYBS模块通过转录和转录后方式精确调控毛白杨茎发育过程中木质素的生物合成。
Abstract. Lignin biosynthesis in the sclerenchyma cells is strictly controlled by a complex network of genetic and environmental signals. In the last decades, the transcriptional regulation of lignin synthesis in woody species has been established. However, the role of microRNA-mediated post-transcriptional modulation in secondary cell wall biosynthesis remains poorly understood. Here, we identified a microRNA, miR828, involved in the regulation specific to lignin biosynthesis during stem development in Populus tomentosa Carr. miR828 is preferentially expressed in the secondary vascular tissues during stem development. Two MYB genes (MYB171 and MYB011) were validated as direct targets of miR828 by degradome analysis and green fluorescent protein signal detection. Overexpression of miR828 in poplar downregulated genes for lignin biosynthesis, resulting in reduced lignin content in cell walls. Conversely, suppression of miR828 in plants by the short tandem target mimics elevated the expression of lignin biosynthetic genes and increased lignin deposition. We further revealed that poplar MYB171, as the most abundant miR828 target in the stem, is a positive regulator for lignin biosynthesis. Transient expression assays showed that both MYB171 and MYB011 activated PAL1 and CCR2 transcription, whereas the introduction of miR828 significantly suppressed their expression that was induced by MYB171 or MYB011. Collectively, our results demonstrate that the miR828-MYBs module precisely regulates lignin biosynthesis during the stem development in P. tomentosa through transcriptional and post-transcriptional manners.