National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, 430070 Wuhan, China.
Institute for Interdisciplinary Research, Jianghan University, 430056 Wuhan, China.
Nucleic Acids Res. 2018 Mar 16;46(5):2356-2369. doi: 10.1093/nar/gky017.
WUSCHEL-related homeobox (WOX) genes are key regulators of meristem activity and plant development, the chromatin mechanism of which to reprogram gene expression remains unclear. Histone H3K27me3 is a chromatin mark of developmentally repressed genes. How the repressive mark is removed from specific genes during plant development is largely unknown. Here, we show that WOX11 interacts with the H3K27me3 demethylase JMJ705 to activate gene expression during shoot development in rice. Genetic analysis indicates that WOX11 and JMJ705 cooperatively control shoot growth and commonly regulate the expression of a set of genes involved in meristem identity, chloroplast biogenesis, and energy metabolism in the shoot apex. Loss of WOX11 led to increased H3K27me3 and overexpression of JMJ705 decreased the methylation levels at a subset of common targets. JMJ705 is associated with most of the WOX11-binding sites found in the tested common targets in vivo, regardless of presence or absence of the JMJ705-binding motif. Furthermore, wox11 mutation reduced JMJ705-binding to many targets genome-wide. The results suggest that recruitment of JMJ705 to specific developmental pathway genes is promoted by DNA-binding transcription factors and that WOX11 functions to stimulate shoot growth through epigenetic reprogramming of genes involved in meristem development and energy-generating pathways.
WOX 基因家族与植物发育和分生组织活性的调控密切相关，但其重塑基因表达的染色质机制尚不清楚。组蛋白 H3K27me3 是发育抑制基因的染色质标记。在植物发育过程中，如何从特定基因上去除抑制性标记，目前还知之甚少。本文中，作者发现 WOX11 与 H3K27me3 去甲基化酶 JMJ705 互作，在水稻的 Shoot 发育过程中激活基因表达。遗传分析表明，WOX11 和 JMJ705 协同控制 Shoot 生长，共同调控一组参与 Shoot 顶端分生组织身份、叶绿体生物发生和能量代谢的基因的表达。WOX11 的缺失导致 H3K27me3 增加，而 JMJ705 的过表达则降低了一组共同靶基因的甲基化水平。在体内，JMJ705 与大多数在测试的共同靶基因中发现的 WOX11 结合位点相关联，无论 JMJ705 结合基序是否存在。此外，wox11 突变减少了 JMJ705 对许多全基因组靶基因的结合。这些结果表明，JMJ705 被募集到特定的发育途径基因，是由 DNA 结合转录因子所促进的，而 WOX11 通过对参与分生组织发育和能量产生途径的基因进行表观遗传重编程来刺激 Shoot 生长。
