Saclay Plant Science, Institut de Biologie des Plantes, Université Paris-Sud 11 Orsay, France.
Saclay Plant Science, Institut de Biologie des Plantes, Université Paris-Sud 11 Orsay, France ; UMR 8618, CNRS Orsay, France.
Front Plant Sci. 2014 Jun 24;5:290. doi: 10.3389/fpls.2014.00290. eCollection 2014.
Histone H3 lysine 4 trimethylation (H3K4me3) has been shown to be involved in stress-responsive gene expression and gene priming in plants. However, the role of H3K4me3 resetting in the processes is not clear. In this work we studied the expression and function of Arabidopsis H3K4 demethylase gene JMJ15. We show that the expression of JMJ15 was relatively low and was limited to a number of tissues during vegetative growth but was higher in young floral organs. Over-expression of the gene in gain-of-function mutants reduced the plant height with accumulation of lignin in stems, while the loss-of-function mutation did not produce any visible phenotype. The gain-of-function mutants showed enhanced salt tolerance, whereas the loss-of-function mutant was more sensitive to salt compared to the wild type. Transcriptomic analysis revealed that over-expression of JMJ15 down-regulated many genes which are preferentially marked by H3K4me3 and H3K4me2. Many of the down-regulated genes encode transcription regulators involved in stress responses. The data suggest that increased JMJ15 levels may regulate the gene expression program that enhances stress tolerance.
组蛋白 H3 赖氨酸 4 三甲基化（H3K4me3）已被证明参与植物中应激响应基因表达和基因启动。然而，H3K4me3 重置在这些过程中的作用尚不清楚。在这项工作中，我们研究了拟南芥 H3K4 去甲基化酶基因 JMJ15 的表达和功能。我们发现，JMJ15 的表达水平相对较低，在营养生长过程中仅限于少数组织，但在年轻的花器官中表达水平较高。该基因在功能获得性突变体中的过表达导致植物高度降低，同时茎干中木质素积累，而功能丧失性突变体则没有产生任何可见的表型。功能获得性突变体表现出增强的耐盐性，而与野生型相比，功能丧失性突变体对盐更敏感。转录组分析表明，JMJ15 的过表达下调了许多被 H3K4me3 和 H3K4me2 优先标记的基因。许多下调的基因编码参与应激反应的转录调节剂。数据表明，JMJ15 水平的增加可能调节增强应激耐受性的基因表达程序。
