Histone H3K9 demethylase JMJ25 epigenetically modulates anthocyanin biosynthesis in poplar
Histone H3K9 demethylase JMJ25 epigenetically modulates anthocyanin biosynthesis in poplar
复制标题
组蛋白 H3K9 去甲基化酶 JMJ25 表观遗传调节杨花青素生物合成
DOI：
10.1111/tpj.14092
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发表时间：
2018-12-01
期刊：
影响因子：
7.2
通讯作者：
Luo, Keming
中科院分区：
文献类型：
--
作者：
Fan, Di;Wang, Xianqiang;Luo, Keming
花色苷参与白杨的生长发育和防御过程。虽然在过去的几十年里，在揭示这些花青素的生物合成和调控机制方面取得了重大进展，但对该途径中的表观遗传调控的基本理解仍然很不清楚。本研究从杨属植物中克隆了一个组蛋白H3 K9脱甲基酶基因JMJ 25，并通过遗传学和生物化学方法研究了该基因在花青素合成中的作用。JMJ 25通过连续黑暗处理诱导。过量表达JMJ 25导致转基因白杨花青苷生物合成基因的表达下调，导致花青苷含量显著降低。ChIP-qPCR检测结果显示JMJ 25可以直接与MYB 182染色质结合，并在H3 K9 me 2处动态去甲基化。此外，JMJ 25还影响MYB 182的DNA甲基化水平。相比之下，通过CRISPR/Cas9敲除JMJ 25导致在黑暗条件下异位花青素积累，并增加花青素生物合成基因的表达。我们的研究结果支持了一个模型，其中JMJ 25通过改变其染色质和DNA甲基化的组蛋白甲基化状态直接影响MYB 182的表达，导致花青素积累的抑制。本研究揭示了调控白杨花色素苷生物合成的表观遗传机制。
Anthocyanins are involved in several aspects of development and defence in poplar (Populus spp.). Although, over the past decades, significant progress has been made in uncovering these anthocyanin biosynthetic and regulatory mechanisms, the fundamental understanding of the epigenetic regulation in this pathway is still largely unclear. Here, we isolated a histone H3K9 demethylase gene JMJ25 from Populus and characterized its role in anthocyanin biosynthesis by genetic and biochemical approaches. JMJ25 was induced by continuous dark treatment. Overexpression of JMJ25 led to downregulated expression of anthocyanin biosynthetic genes in transgenic poplar, resulting in a significant reduction in anthocyanin content. ChIP-qPCR assays showed that JMJ25 could directly associate with MYB182 chromatin and dynamically demethylate at H3K9me2. Furthermore, JMJ25 also affected the DNA methylation levels of MYB182. By contrast, knockout of JMJ25 by CRISPR/Cas9 resulted in ectopic anthocyanin accumulation under dark condition and increased expression of anthocyanin biosynthetic genes. Our results support a model in which JMJ25 directly affects MYB182 expression by altering the histone methylation status of its chromatin and DNA methylation, resulting in repression of anthocyanin accumulation. This study uncovered an epigenetic mechanism that modulates anthocyanin biosynthesis in poplar.