Arabidopsis RNA-binding Protein FCA Regulates MicroRNA172 Processing in Thermosensory Flowering
Arabidopsis RNA-binding Protein FCA Regulates MicroRNA172 Processing in Thermosensory Flowering
复制标题
DOI：
10.1074/jbc.m111.337485
复制
发表时间：
2012-05-04
影响因子：
4.8
通讯作者：
Park, Chung-Mo
中科院分区：
文献类型：
--
作者：
Jung, Jae-Hoon;Seo, Pil Joon;Park, Chung-Mo
环境温度有日变化和季节变化。它深刻地影响着植物开花的时间。花整合子FLOWERLOCUS T（FT）通过拟南芥开花中的温度传感途径介导环境温度信号。microRNA 172（miR 172）通过诱导FT促进开花，也响应环境温度的变化。然而，miR 172是如何将环境温度信号整合到开花遗传网络中的，这在很大程度上是未知的。在这里，我们表明，拟南芥RNA结合蛋白FCA促进初级microRNA 172转录（pri-miR 172）的加工，以响应环境温度的变化。环境温度主要在pri-miR 172加工步骤调节miR 172生物发生。miR 172丰度在23 ℃升高，但在16 ℃不升高。23 ℃下的miR 172积累需要功能性FCA。FCA通过RNA识别基序与pri-miR 172转录物中茎环的侧翼序列结合。FCA还结合其他温度响应性miRNA的初级转录物，如miR 398和miR 399。值得注意的是，FCA mRNA和蛋白质的水平在23 ℃时增加，但在16 ℃时保持较低水平，这支持了FCA在温度感知中的作用。我们的数据表明，FCA调控的miR 172处理是一个早期事件的热敏开花途径。我们认为FCA-miR 172调节子提供了一种自适应策略，可以在波动的环境温度条件下微调开花的开始。
Ambient temperature fluctuates diurnally and seasonally. It profoundly influences the timing of flowering in plants. The floral integrator FLOWERING LOCUS T (FT) mediates ambient temperature signals via the thermosensory pathway in Arabidopsis flowering. microRNA172 (miR172), which promotes flowering by inducing FT, also responds to changes in ambient temperature. However, it is largely unknown how miR172 integrates ambient temperature signals into the flowering genetic network. Here, we show that Arabidopsis RNA-binding protein FCA promotes the processing of primary microRNA172 transcripts (pri-miR172) in response to changes in ambient temperature. Ambient temperature regulates miR172 biogenesis primarily at the pri-miR172 processing step. miR172 abundance is elevated at 23 degrees C but not at 16 degrees C. miR172 accumulation at 23 degrees C requires functional FCA. FCA binds to the flanking sequences of the stem-loop within the pri-miR172 transcripts via the RNA recognition motif. FCA also binds to the primary transcripts of other temperature-responsive miRNAs, such as miR398 and miR399. Notably, levels of FCA mRNAs and proteins increase at 23 degrees C but remain low at 16 degrees C, supporting the role of FCA in temperature perception. Our data show that FCA regulation of miR172 processing is an early event in the thermosensory flowering pathway. We propose that the FCA-miR172 regulon provides an adaptive strategy that fine tunes the onset of flowering under fluctuating ambient temperature conditions.