背景回顾：Plants use seasonal temperature cues to time the transition to reproduction. In Arabidopsis thaliana, winter cold epigenetically silences the floral repressor locus FLOWERING LOCUS C (FLC) through POLYCOMB REPRESSIVE COMPLEX 2 (PRC2). This vernalization process aligns flowering with spring. 

提出问题：A prerequisite for silencing is transcriptional downregulation of FLC, but how this occurs in the fluctuating temperature regimes of autumn is unknown. 

研究基础：Transcriptional repression correlates with decreased local levels of histone H3 trimethylation at K36 (H3K36me3) and H3 trimethylation at K4 (H3K4me3), which are deposited during FRIGIDA (FRI)-dependent activation of FLC. 

结果1-低温诱导FRI核凝聚：Here we show that coldrapidly promotes the formation of FRI nuclear condensates that do not colocalize with an active FLC locus. This correlates with reduced FRI occupancy at the FLC promoter and FLC repression. 

结果2-温暖的温度缓冲FLC沉默：Warm temperature spikes reverse this process, buffering FLC shutdown to prevent premature flowering. 

结果3-低温诱导凝聚积累的调控子：The accumulation of condensates in the cold is affected by specific co-transcriptional regulators and cold induction of a specific isoform of the antisense RNA COOLAIR. 

结论：Our work describes the dynamic partitioning of a transcriptional activator conferring plasticity in response to natural temperature fluctuations, thus enabling plants to effectively monitor seasonal progression.

 摘 要 

植物利用季节性温度信号来确定何时向生殖生长发育转变。在拟南芥中，冬季低温会通过PRC2表观沉默开花抑制因子FLC。该春化过程使得拟南芥能够在春季开花。基因沉默的一个先决条件是FLC的转录下调，但是该过程在秋季波动的温度下是如何发生的还不清楚。转录抑制与H3K36me3和H3K4me3水平的降低有关，这两种组蛋白修饰是在FRI依赖性的FLC激活过程中沉积的。本文中，作者发现低温能够迅速促进FRI核凝聚的形成，但并不与活跃的FLC位点共定位。这与FLC启动子区上的FRI占据减少和FLC抑制相关联。温暖的温度峰会逆转这一进程，缓冲FLC的转录沉默，以防止过早开花。低温下的凝聚积累受到特定共表达调控子和反义RNA COOLAIR特定异构体低温诱导的影响。本文的研究揭示了一种转录激活子的动态分隔，赋予其在响应自然温度波动时的可塑性，从而使得植物能够有效地监测季节变化。