春化是促进冬性植物开花的重要途径，在拟南芥中春化可导致FLC基因发生沉默。目前已知这一过程需要多种成分参与，包括长链非编码RNA COOLAIR、 COLDAIR以及多梳族蛋白复合体PHD-PRC2等。它们通过调节H3K36me3和H3K27me3修饰水平发挥作用。已知春化过程中最早发生的事件包括H3K36me3修饰水平下降和COOLAIR表达水平上调，但启动春化的具体调控机理尚不清楚。本项目将通过分析1）组蛋白H3K36me3甲基转移酶活性在春化早期是否被抑制；2）寻找在春化早期发挥作用的H3K36me3去甲基化酶；和3）COOLAIR如何协助春化早期H3K36me3去甲基化过程来控制FLC基因的沉默等三方面来解析春化早期H3K36me3去甲基化的发生机制并寻找这一过程中新的作用因子。实施本项目将在植物表观遗传学包括组蛋白修饰和长链非编码RNA调控机理方面产生新理论，并可望指导农业生产。

For winter annual plants, the exposure to a prolonged cold is essential to flower in the spring. This process is called as vernalization, which involves the traditional epigenetic gene silencing mechanism. In Arabidopsis, the main target of vernalization is the FLC gene, and the silencing mechanism requires the long non-coding RNAs (lncRNAs) COOLAIR and COLDAIR, and the Polycomb Repressive Complex PHD-PRC2 for quantitatively decreasing of H3K36me3 and increasing of H3K27me3 levels. It has been reported that the earliest events for proper vernalization initiation are the reduction of H3K36me3 level and the induction of COOLAIR RNA expression. However, the regulatory mechanism for vernalization initiation, like how the H3K36me3 demethylation process regulated, have not been investigated. This project will: 1) analyze the H3K36me3 methyltransferases activities during vernalization initiation; 2) identify the H3K36me3 demethylases that function in vernalization initiation; and 3) how lncRNA COOLAIR involved in initiation of vernalization. Results obtained from this project will reveal the mechanism of vernalization initiation and identify new components involved in this process. I believe that this project will achieve a significant progress and breakthrough in plant epigenetics like histone modifications regulation and lncRNA functions; and may guide for better crop production.