组蛋白赖氨酸甲基转移酶SDG8基因参与植物春化途径的开花调控，但是它如何调节开花期的早晚还是一个未知。我们在研究白菜、甘蓝和甘蓝型油菜三个物种SDG8基因的过程中，偶然发现在SDG8的N端未知功能区，存在一段由39个氨基酸残基组成的保守序列（暂命名为VHE基序）；且白菜BraSDG8中只有1个VHE；甘蓝BolSDG8中有2个连续的VHE；甘蓝型油菜A/C组的SDG8分别含1个和2个VHE。进一步分析发现VHE只存在于十字花科的SDG8中；而SDG8参与春化途径的开花调控，相同条件下，越冬后三种油菜的开花期为白菜早于甘蓝型油菜，甘蓝型油菜早于甘蓝。综合分析后，我们推测VHE的数量可能与SDG8调控植物进入开花期的早晚有关。为此，本项目拟通过表观遗传学、分子生物学等技术手段，揭示SDG8蛋白中新发现VHE的作用，这对人们深入认识春化条件下油菜花期形成的精细表观调控机制具有积极意义。

One of the main biological functions of histone lysine methyl transferase SDG8 gene is to control flowering, but it is still unknown how to regulate the time of flowering. The Arabidopsis SDG8, with a variety of physiological functions, has four known functional domains close to its C-terminal. But the function of its more than 350 amino acid residues N-terminal is still unknown. The full-length CDS of the SDG8 genes had been cloned from Brassica rapa, Brassica oleracea and Brassica napus, respectively. During the SNP primer-designing progress, we occasionally found that, in the function-unknown more than 350 amino acids sequence, there is a conserved protein domain, consisting of 39 amino acids, temporarily named VHE domain. What’s more, there are two successive VHE domains in the SDG8 protein of Brassica oleracea, and only one in the SDG8 proteins of Brassica rapa and Arabidopsis. According to statistical flowering time after the winter, Brassica rapa boltings earlier than Brassica napus and Brassica napus boltings earlier than Brasicca oleracea. Combining the bioinformatics analysis, by.which we found that the VHE domain only exits in the protein SDG8 involved in flowering control, and statistical analysis of the time to bolting in the three species of rape, we infered that the new VHE domain is likely to be associated with the time to bolting of plants in Cruciferae. Therefor, by dint of the epigenetics, molecular biology techniques and so on, this project aim is to uncover the function of the novel VHE domain of the SDG8 proteins, which will have positive significance for deeply insight of the epigenetic regultion mechnism of flowering in Brassicaceae.