Pseudo Response Regulators Regulate Photoperiodic Hypocotyl Growth by RepressingPIF4/5Transcription1[OPEN]
Pseudo Response Regulators Regulate Photoperiodic Hypocotyl Growth by RepressingPIF4/5Transcription1[OPEN]
复制标题
伪响应调节剂通过抑制 PIF4/5 转录调节光周期下胚轴生长(1)([OPEN])
DOI：
10.1104/pp.19.01599
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发表时间：
2020-06-01
期刊：
影响因子：
7.4
通讯作者：
Wang, Lei
中科院分区：
文献类型：
--
作者：
Li, Na;Zhang, Yuanyuan;Wang, Lei
生物钟测量并传递日长信息，以控制光周期条件下有节律的下胚轴生长，以实现最佳适应度，但它通过很大程度上未知的机制来运作。在这里，我们展示了伪响应调节器（PRR）与晚间复合物（EC）（时钟核心振荡器内的转录抑制复合物）协调，特异性调节拟南芥（Arabidopsis thaliana）的光周期下胚轴生长。有趣的是，不同的日长可以改变表达阶段并延长 PRR 的表达持续时间。多种证据进一步证明PRRs直接结合PHYTOCHROME-INTERACTING FACTOR4(PIF4)和PIF5的启动子来抑制其表达，因此PRRs充当正生长调节因子PIF4和PIF5的转录抑制子。重要的是，CAB EXPRESSION1 (TOC1) DNA 结合结构域的突变或截短，在不影响其与 PIF 的物理相互作用的情况下，仍然会在短日照下引起长下胚轴生长，凸显了 PRR-PIF 转录模块在光周期下胚轴生长中的重要作用。最后，遗传分析表明PIF4和PIF5在光周期下胚轴生长调节中对PRRs具有上位性。总的来说，我们认为，在感知日长信息后，PRRs与EC合作直接抑制PIF4和PIF5转录及其对PIF活性的翻译后调节，从而形成一个复杂的调节网络来介导生物钟调节的光周期生长。伪响应调节蛋白和晚间复合体通过直接抑制关键生长调节剂的转录来传递日长信息来调节光周期下胚轴生长。
The circadian clock measures and conveys daylength information to control rhythmic hypocotyl growth in photoperiodic conditions to achieve optimal fitness, but it operates through largely unknown mechanisms. Here, we show that Pseudo Response Regulators (PRRs) coordinate with the Evening Complex (EC), a transcriptional repressor complex within the clock core oscillator, to specifically regulate photoperiodic hypocotyl growth in Arabidopsis (Arabidopsis thaliana). Intriguingly, a distinct daylength could shift the expression phase and extend the expression duration of PRRs. Multiple lines of evidence have further demonstrated that PRRs directly bind the promoters ofPHYTOCHROME-INTERACTING FACTOR4(PIF4) andPIF5to repress their expression, hence PRRs act as transcriptional repressors of the positive growth regulatorsPIF4andPIF5. Importantly, mutation or truncation of the TIMING OF CAB EXPRESSION1 (TOC1) DNA binding domain, without compromising its physical interaction with PIFs, still caused long hypocotyl growth under short days, highlighting the essential role of the PRR-PIFtranscriptional module in photoperiodic hypocotyl growth. Finally, genetic analyses have demonstrated thatPIF4andPIF5are epistatic toPRRsin the regulation of photoperiodic hypocotyl growth. Collectively, we propose that, upon perceiving daylength information, PRRs cooperate with EC to directly repressPIF4andPIF5transcription together with their posttranslational regulation of PIF activities, thus forming a complex regulatory network to mediate circadian clock-regulated photoperiodic growth.Pseudo Response Regulator proteins and the Evening Complex transmit daylength information to regulate photoperiodic hypocotyl growth by directly repressing transcription of key growth regulators.