Linked circadian outputs control elongation growth and flowering in response to photoperiod and temperature.
Linked circadian outputs control elongation growth and flowering in response to photoperiod and temperature.
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DOI：
10.15252/msb.20145766
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发表时间：
2015-01-19
影响因子：
9.9
通讯作者：
Halliday KJ
中科院分区：
文献类型：
--
作者：
Seaton DD;Smith RW;Song YH;MacGregor DR;Stewart K;Steel G;Foreman J;Penfield S;Imaizumi T;Millar AJ;Halliday KJ
生物钟调节的途径协调了许多发育过程对光周期和温度变化的反应。我们模拟了拟南芥中两个最容易理解的时钟输出途径，它们控制着开花和伸长生长的关键调节因子。在开花过程中，该模型预测了从时钟到循环DOF因子1 （CDF1）和黄素结合、KELCH REPEAT、F-BOX 1 （FKF1）转录的调控联系。物理相互作用数据支持这些联系，这些联系创建了从两个时钟组件到花调节因子FT的三重前馈基序。在下胚轴生长中，该模型描述了时钟调节的光敏色素相互作用因子4和5 （PIF4, PIF5）的转录，与光敏色素B （phyB）和其他光激活途径对PIF蛋白的翻译后调节相互作用。该模型预测了在数百个PIF调节的靶基因中观察到的双峰和终末PIF活性谱。在对温度的响应中，温度增强的PIF4活性解释了观察到的下胚轴生长动力学，但另外，温度依赖性调节因子与开花响应有关。将这两种途径与时钟模型相结合，突出了在变化条件下协调植物发育的分子机制。
Clock-regulated pathways coordinate the response of many developmental processes to changes in photoperiod and temperature. We model two of the best-understood clock output pathways in Arabidopsis, which control key regulators of flowering and elongation growth. In flowering, the model predicted regulatory links from the clock to CYCLING DOF FACTOR 1 (CDF1) and FLAVIN-BINDING, KELCH REPEAT, F-BOX 1 (FKF1) transcription. Physical interaction data support these links, which create threefold feed-forward motifs from two clock components to the floral regulator FT. In hypocotyl growth, the model described clock-regulated transcription of PHYTOCHROME-INTERACTING FACTOR 4 and 5 (PIF4, PIF5), interacting with post-translational regulation of PIF proteins by phytochrome B (phyB) and other light-activated pathways. The model predicted bimodal and end-of-day PIF activity profiles that are observed across hundreds of PIF-regulated target genes. In the response to temperature, warmth-enhanced PIF4 activity explained the observed hypocotyl growth dynamics but additional, temperature-dependent regulators were implicated in the flowering response. Integrating these two pathways with the clock model highlights the molecular mechanisms that coordinate plant development across changing conditions.