State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, China.
MOE Key Laboratory of Crop Heterosis and Utilization, College of Agronomy and Biotechnology, China Agricultural University, Beijing, China.
EMBO J. 2020 Jul 1;39(13):e103630. doi: 10.15252/embj.2019103630. Epub 2020 May 25.
Light and temperature are two core environmental factors that coordinately regulate plant growth and survival throughout their entire life cycle. However, the mechanisms integrating light and temperature signaling pathways in plants remain poorly understood. Here, we report that CBF1, an AP2/ERF-family transcription factor essential for plant cold acclimation, promotes hypocotyl growth under ambient temperatures in Arabidopsis. We show that CBF1 increases the protein abundance of PIF4 and PIF5, two phytochrome-interacting bHLH-family transcription factors that play pivotal roles in modulating plant growth and development, by directly binding to their promoters to induce their gene expression, and by inhibiting their interaction with phyB in the light. Moreover, our data demonstrate that CBF1 promotes PIF4/PIF5 protein accumulation and hypocotyl growth at both 22°C and 17°C, but not at 4°C, with a more prominent role at 17°C than at 22°C. Together, our study reveals that CBF1 integrates light and temperature control of hypocotyl growth by promoting PIF4 and PIF5 protein abundance in the light, thus providing insights into the integration mechanisms of light and temperature signaling pathways in plants.
光是植物生长和存活的主要环境因素之一，而温度则是另外一个主要的环境因素，这两个因素在植物的整个生命周期中协同调节植物的生长和存活。然而，将光和温度信号通路整合在一起的机制在植物中仍然知之甚少。在这里，我们报道了 CBF1，它是植物冷驯化所必需的 AP2/ERF 家族转录因子，它促进拟南芥在环境温度下的下胚轴生长。我们表明，CBF1 通过直接结合到它们的启动子上诱导它们的基因表达，并通过在光下抑制它们与 phyB 的相互作用，增加了 PIF4 和 PIF5 的蛋白丰度，PIF4 和 PIF5 是两个参与调节植物生长和发育的光受体相互作用的 bHLH 家族转录因子。此外，我们的数据表明，CBF1 在 22°C 和 17°C 下促进 PIF4/PIF5 蛋白积累和下胚轴生长，但在 4°C 下则没有，在 17°C 下的作用比在 22°C 下更显著。总之，我们的研究揭示了 CBF1 通过在光下促进 PIF4 和 PIF5 蛋白丰度来整合光和温度对下胚轴生长的控制，从而为植物中光和温度信号通路的整合机制提供了新的见解。
