PHYTOCHROME-INTERACTING FACTOR 4/HEMERA-mediated thermosensory growth requires the Mediator subunit MED14.
PHYTOCHROME-INTERACTING FACTOR 4/HEMERA-mediated thermosensory growth requires the Mediator subunit MED14.
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DOI：
10.1093/plphys/kiac412
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发表时间：
2022-11-28
期刊：
影响因子：
7.4
通讯作者：
Qiu, Yongjian
中科院分区：
文献类型：
--
作者：
Bajracharya, Abhishesh;Xi, Jing;Grace, Karlie F.;Bayer, Eden E.;Grant, Chloe A.;Clutton, Caroline H.;Baerson, Scott R.;Agarwal, Ameeta K.;Qiu, Yongjian
虽然适度升高的环境温度不会引发植物的应激反应，但它们确实通过称为热形态发生的过程显着刺激特定器官的生长。基本的螺旋-环-螺旋转录因子植物色素相互作用因子 4 (PIF4) 在调节各种植物物种的热形态发生下胚轴伸长中发挥着核心作用，包括拟南芥 (Arabidopsis thaliana)。尽管众所周知，PIF4及其共激活剂HEMERA (HMR)通过激活参与植物激素生长素生物合成和信号传导的基因来促进植物热感生长，但这种转录激活的详细分子机制尚不清楚。在本报告中，我们研究了介导复合物在 PIF4/HMR 介导的热响应基因表达中的作用。通过对介体复合体各种突变体的表征，一个名为 MED14 的尾亚基被确定为热形态发生下胚轴生长的重要因子。 MED14 是 PIF4 靶基因热诱导所必需的，但对 PIF4 和 HMR 的水平具有边际影响。进一步的转录组分析证实，许多 PIF4/HMR 依赖性、生长素相关基因的表达在温暖的温度下需要 MED14。此外，PIF4 和 HMR 与 MED14 发生物理相互作用，对于 MED14 与这些热响应基因的启动子的关联都是不可或缺的。虽然 PIF4 不调节 MED14 水平，但 HMR 是 MED14 转录本丰度所必需的。总而言之，这些结果揭示了一种重要的热形态发生机制，其中当植物感知到环境温度适度升高时，PIF4 和 HMR 招募介体复合物来激活与生长素相关的生长促进基因。介体亚基 MED14 通过与 PHYTOCHROME 相互作用因子 4 和 HEMERA 相互作用来促进热形态发生，从而诱导生长促进基因在高温下的表达。
While moderately elevated ambient temperatures do not trigger stress responses in plants, they do substantially stimulate the growth of specific organs through a process known as thermomorphogenesis. The basic helix–loop–helix transcription factor PHYTOCHROME-INTERACTING FACTOR 4 (PIF4) plays a central role in regulating thermomorphogenetic hypocotyl elongation in various plant species, including Arabidopsis (Arabidopsis thaliana). Although it is well known that PIF4 and its co-activator HEMERA (HMR) promote plant thermosensory growth by activating genes involved in the biosynthesis and signaling of the phytohormone auxin, the detailed molecular mechanism of such transcriptional activation is not clear. In this report, we investigated the role of the Mediator complex in the PIF4/HMR-mediated thermoresponsive gene expression. Through the characterization of various mutants of the Mediator complex, a tail subunit named MED14 was identified as an essential factor for thermomorphogenetic hypocotyl growth. MED14 was required for the thermal induction of PIF4 target genes but had a marginal effect on the levels of PIF4 and HMR. Further transcriptomic analyses confirmed that the expression of numerous PIF4/HMR-dependent, auxin-related genes required MED14 at warm temperatures. Moreover, PIF4 and HMR physically interacted with MED14 and both were indispensable for the association of MED14 with the promoters of these thermoresponsive genes. While PIF4 did not regulate MED14 levels, HMR was required for the transcript abundance of MED14. Taken together, these results unveil an important thermomorphogenetic mechanism, in which PIF4 and HMR recruit the Mediator complex to activate auxin-related growth-promoting genes when plants sense moderate increases in ambient temperature. The Mediator subunit MED14 promotes thermomorphogenesis by interacting with PHYTOCHROME-INTERACTING FACTOR 4 and HEMERA to induce the expression of growth-promoting genes at elevated temperatures.
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影响因子：
5.6
作者：
Lee M;Dominguez-Ferreras A;Kaliyadasa E;Huang WJ;Antony E;Stevenson T;Lehmann S;Schäfer P;Knight MR;Ntoukakis V;Knight H
通讯作者：
Knight H
影响因子：
5.6
作者：
Dalton JC;Bätz U;Liu J;Curie GL;Quail PH
通讯作者：
Quail PH
影响因子：
11.6
作者：
Dolan, Whitney L.;Dilkes, Brian P.;Chapple, Clint
通讯作者：
Chapple, Clint
影响因子：
8.8
作者：
Ding, Lan;Wang, Shuo;Liu, Jian-Xiang
通讯作者：
Liu, Jian-Xiang
DOI：
10.1111/tpj.12639
发表时间：
2014-11
期刊：
The Plant journal : for cell and molecular biology
影响因子：
--
作者：
Gookin TE;Assmann SM
通讯作者：
Assmann SM