先锋TFs：Pioneer transcription factors (TFs) are a special category of TFs with the capacity to bind to closed chromatin regions in which DNA is wrapped around histones and may be highly methylated. Subsequently, pioneer TFs are able to modify the chromatin state to initiate gene expression. 

LEAFY：In plants, LEAFY (LFY) is a master floral regulator and has been suggested to act as a pioneer TF in Arabidopsis. 

结果1-体外试验：Here, we demonstrate that LFY is able to bind both methylated and non-methylated DNA using a combination of in vitro genome-wide binding experiments and structural modeling. 

结果2-体内试验：Comparisons between regions bound by LFY in vivo and chromatin accessibility data suggest that a subset of LFY bound regions is occupied by nucleosomes. 

结果3-验证：We confirm that LFY is able to bind nucleosomal DNA in vitro using reconstituted nucleosomes. 

结果4-LFY调控开花基因：Finally, we show that constitutive LFY expression in seedling tissues is sufficient to induce chromatin accessibility in the LFY direct target genes, APETALA1 and AGAMOUS. 

结论：Taken together, our study suggests that LFY possesses key pioneer TF features that contribute to launch the floral gene expression program.

 摘 要 

先锋转录因子是一类特别的转录因子，可以结合到还未开放的染色质上，此时的DNA仍旧缠绕在组蛋白上，并且可能被高度甲基化。随后，先锋转录因子能够改变染色质状态，从而起始基因的转录。在植物中，LEAFY是一个促进开花的主要转录因子，被认为在拟南芥中发挥着先锋转录因子的功能。本文中，作者结合体外全基因组结合试验和结构模拟，揭示了LFY能够结合到甲基化和非甲基化的DNA。通过比较体内LFY结合区域和染色质可及性数据，作者发现LFY结合的区域很大一部分被核小体占据着。作者通过重组的核小体，进一步确认了LFY能够在体内结合到核小体DNA上。最终，作者的研究显示LEAFY在幼苗中组成型的表达能够诱导LFY直接靶基因AP1和AG的染色质开放。综上，本文的研究揭示了LFY就有先锋转录因子的关键特征，作用于启动成花基因的表达程序。