背景回顾：Arabidopsis (Arabidopsis thaliana) FLOWERING LOCUS C (FLC) acts as a key flowering regulator by repressing the expression of the floral integrator FLOWERING LOCUS T (FT). Prolonged exposure to cold (vernalization) induces flowering by reducing FLC expression. The long noncoding RNAs (lncRNAs) COOLAIR and COLDAIR, which are transcribed from the 3’ end and the first intron of FLC, respectively, are important for FLC repression under vernalization. 

提出问题：However, the molecular mechanism of how COOLAIR and COLDAIR are transcriptionally activated remains elusive. 

主要发现：In this study, we found that the group-III WRKY transcription factor WRKY63 can directly activate FLC. 

结果1-wrky63突变体表型：wrky63 mutant plants display an early flowering phenotype and are insensitive to vernalization. 

结果2-WRKY63转录激活COOLAIR和COLDAIR：Interestingly, we found that WRKY63 can activate the expression of COOLAIR and COLDAIR by binding to their promoters. 

结果3-WRKY63结合DNA能力：Furthermore, genome-wide occupancy profile analyses indicated that the binding of WRKY63 to vernalization-induced genes increases after vernalization. In addition, WRKY63 binding is associated with decreased levels of the repressive marker Histone H3 Lysine 27 trimethylation (H3K27me3). 

结论：Collectively, our results indicate that WRKY63 is an important flowering regulator involved in vernalization-induced transcriptional regulation.

 摘 要 

拟南芥FLC通过抑制开花基因FT的表达，从而调控开花。持续的低温即春化处理会通过降低FLC基因的表达，从而诱导开花。长链非编码RNA（lncRNA）COOLAIR和COLDAIR是分别从FLC基因的3’端和第一个内含子转录形成，对于FLC基因在春化处理后的表达调控至关重要。但是，COOLAIR和COLDAIR两个lncRNAs是如何被转录激活的还不清楚。本文中，作者发现WRKY家族group-III的WRKY63能够直接激活FLC基因。wrky63突变体表现出早花的表型，且对于春化处理不敏感。有趣的是，作者发现WRKY63能够通过结合到COOLAIR和COLDAIR的启动子上，激活其表达。此外，通过对WRKY63在全基因组范围上的结合谱分析显示，在春化处理后WRKY63结合到春化诱导基因上的能力得到增强。另外，WRKY63的结合与抑制性标记H3K27me3的水平降低相关。综上，本文的研究结果揭示了WRKY63参与了春化诱导的转录调控，从而在植物开花中发挥重要调控作用。