The Chromatin-Remodeling Factor PICKLE Antagonizes Polycomb Repression of FT to Promote Flowering
The Chromatin-Remodeling Factor PICKLE Antagonizes Polycomb Repression of FT to Promote Flowering
复制标题
染色质重塑因子 PICKLE 拮抗多梳蛋白对 FT 的抑制，促进开花
DOI：
10.1104/pp.19.00596
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发表时间：
2019-10-01
期刊：
影响因子：
7.4
通讯作者：
Lin, Rongcheng
中科院分区：
文献类型：
--
作者：
Jing, Yanjun;Guo, Qiang;Lin, Rongcheng
昼长（或光周期）的变化是许多植物用来调整其花过渡时间以确保繁殖成功的季节性线索。诱导长日光周期触发开花位点T（开花位点T）的表达，促进开花。FT编码花原的主要成分，在黄昏时通过光周期途径在叶脉中产生；然而，在响应光周期线索时，FT表达的调节仍然知之甚少。在这里，我们报道了Polycomb组（PcG）和Trithorax组（TrxG）蛋白之间的平衡决定了拟南芥（Arabidopsis thaliana）长时间中适当的FT表达。在PcG突变系中，FT被高度抑制，但在染色质重塑因子PICKLE （PKL）和拟南芥TRITHORAX1同源物（ATX1）的额外破坏后，FT的表达下降到几乎野生型的水平和模式，而光周期途径组分的破坏则不受影响。PKL与ATX1相互作用，介导FT位点赖氨酸-4上组蛋白H3的三甲基化，导致PKL和ATX1对PcG蛋白的拮抗作用，调控FT表达。因此，trxg样蛋白PKL阻止pcg介导的沉默，以确保FT的特异性和适当表达，从而决定适当的开花反应。
Changing daylength (or photoperiod) is a seasonal cue used by many plants to adjust the timing of their floral transition to ensure reproductive success. An inductive long-day photoperiod triggers the expression of FLOWERING LOCUS T (FT), which promotes flowering. FT, encoding a major component of florigen, is induced in leaf veins specifically at dusk through the photoperiod pathway; however, the modulation of FT expression in response to photoperiod cues remains poorly understood. Here, we report that the balance between Polycomb group (PcG) and Trithorax group (TrxG) proteins sets appropriate FT expression in long days in Arabidopsis (Arabidopsis thaliana). In PcG mutant lines, FT was highly derepressed, but FT expression was decreased to an almost wild-type level and pattern upon the additional disruption of chromatin-remodeling factors PICKLE (PKL) and ARABIDOPSIS HOMOLOG OF TRITHORAX1 (ATX1), but not by disruption of photoperiod pathway components. PKL interacts with ATX1 to mediate trimethylation of histone H3 on lysine-4 at the FT locus, leading to antagonistic effects of PKL and ATX1 on PcG proteins in the regulation of FT expression. Therefore, the TrxG-like protein PKL prevents PcG-mediated silencing to ensure specific and appropriate expression of FT, thereby determining the proper flowering response.