FHY3 and FAR1 Integrate Light Signals with the miR156-SPL Module-Mediated Aging Pathway to Regulate Arabidopsis Flowering
FHY3 and FAR1 Integrate Light Signals with the miR156-SPL Module-Mediated Aging Pathway to Regulate Arabidopsis Flowering
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FHY3 和 FAR1 将光信号与 miR156-SPL 模块介导的衰老途径整合以调节拟南芥开花
DOI：
10.1016/j.molp.2020.01.013
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发表时间：
2020-03-02
期刊：
影响因子：
27.5
通讯作者：
Wang, Haiyang
中科院分区：
文献类型：
--
作者：
Xie, Yurong;Zhou, Qin;Wang, Haiyang
为了应对来自邻居的光竞争，不耐荫的植物早熟开花以确保繁殖成功和生存。然而，这一关键发育开关背后的分子机制还不清楚。在这里，我们表明，一对对光敏色素A信号传导至关重要的拟南芥转录因子，远红伸长下胚轴3（FHY 3）和远红受损反应1（FAR 1），通过将环境光信号与miR 156-SPL模块介导的衰老途径整合来调节开花时间。我们发现FHY 3和FAR 1直接与三种促进开花的鳞状细胞启动子结合蛋白样（SPL）转录因子SPL 3、SPL 4和SPL 5相互作用，并抑制它们与几个关键开花调控基因的启动子的结合，这些基因包括FRUITFUL（FUL）、LEAFY（LFY）、APETALA 1（AP 1）和MIR 172 C，从而下调它们的转录水平并延迟开花。在模拟的遮荫条件下，SPL 3/4/5蛋白的水平增加，而FHY 3和FAR 1蛋白的水平下降，从而使SPL 3/4/5从FHY 3/FAR 1抑制中释放，以允许FUL、LFY、AP 1和MIR 172 C的激活，从而提早开花。总之，这些结果揭示了一种新的机制，即植物通过整合环境线索（如光照条件）和内部发育程序（miR 156-SPL模块介导的衰老途径）来调节开花时间。
In response to competition for light from their neighbors, shade-intolerant plants flower precociously to ensure reproductive success and survival. However, the molecular mechanisms underlying this key developmental switch are not well understood. Here, we show that a pair of Arabidopsis transcription factors essential for phytochrome A signaling, FAR-RED ELONGATED HYPOCOTYL3 (FHY3) and FARRED IMPAIRED RESPONSE1 (FAR1), regulate flowering time by integrating environmental light signals with the miR156-SPL module-mediated aging pathway. We found that FHY3 and FAR1 directly interact with three flowering-promoting SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE (SPL) transcription factors, SPL3, SPL4, and SPL5, and inhibit their binding to the promoters of several key flowering regulatory genes, including FRUITFUL (FUL), LEAFY (LFY),APETALA1 (AP1), and MIR172C, thus downregulating their transcript levels and delaying flowering. Under simulated shade conditions, levels of SPL3/4/5 proteins increase, whereas levels of FHY3 and FAR1 proteins decline, thus releasing SPL3/4/5 from FHY3/FAR1 inhibition to allow activation of FUL, LFY, AP1, and MIR172C and, consequently, early flowering. Taken together, these results unravel a novel mechanism whereby plants regulate flowering time by integrating environmental cues (such as light conditions) and an internal developmental program (the miR156-SPL module-mediated aging pathway).