中文摘要：

组蛋白共价修饰作为表观遗传修饰的重要部分，主要包括乙酰化和甲酰化、甲基化、磷酸化、泛素化和SUMO化等，它们形成一个复杂的网络共同调控基因的表达，其中组蛋白甲基化修饰成为研究的热点，甲基化主要发生在赖氨酸残基上。近年来，随着有关植物组蛋白赖氨酸甲基化修饰研究的不断深入，发现其通过改变自身赖氨酸残基的甲基化状态和甲基化程度，形成转录激活或者转录抑制标记，调控基因的表达，在植物开花和逆境胁迫的响应过程中起着至关重要的作用。H3组蛋白的赖氨酸甲基化修饰能够调控FLC基因和有关抗性基因的表达，具体表现为：H3K4的三甲基化促进FLC的表达，H3K27的三甲基化则抑制FLC的表达；H3K4me3作为转录激活标记，可激活Ptdlns5P基因的表达，启动响应干旱的脂质合成信号通路，响应干旱胁迫；相反，H3K27me3作为一种转录抑制标记，低水平的H3K27me3诱导CORl5A和ATGOLS3基因表达，它们分别编码叶绿体低温保护蛋白Corl5am和肌醇半乳糖合成酶GOLS，以抵抗寒冷胁迫。文章主要综述了植物组蛋白赖氨酸甲基化修饰参与DNA甲基化、开花过程以及应答逆境胁迫的分子机制。

英文摘要：

Histone modification is one important sort of the epigenetic modifications, including acetylation, formylation, methylation, phosphorylation, ubiquitination and SUMOylation. By forming a complicated network, these modifications control the expression of genes. Histone methylation occurs mainly on the lysine residues, and plays a key role during flowering and stress response of plants, through changing the methylation status of lysine residues and the ratio of methyla- tion. Triple-methylation of H3K4 promotes FLC expression but triple-methylation of H3K27 inhibits its expression. H3K4me3 activates the expression ofPtdlnsSP gene to initiate lipid synthesis signal pathway in response to drought stress. On the contrary, the low levels of H3K27me3 induce the expression of COR15A and ATGOLS3, which encode for low tem- perature protective proteins of chloroplast （Corl5am） and Galactional Synthase （GOLS）, in order to resist cold stress. Inthis review, we summarize the molecular mechanisms of histone lysine methylation involved in DNA methylation, plant flowering and stress response.