High Temperature-Medated Adaptations in Plant Architecture Require the bHLH Transcription Factor PIF4
High Temperature-Medated Adaptations in Plant Architecture Require the bHLH Transcription Factor PIF4
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DOI：
10.1016/j.cub.2009.01.046
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发表时间：
2009-03-10
期刊：
影响因子：
9.2
通讯作者：
Franklin, Keara A.
中科院分区：
文献类型：
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作者：
Koini, Maria A.;Alvey, Liz;Franklin, Keara A.
拟南芥植物暴露在高温(28摄氏度)下会导致植物发育的巨大变化。对高温的反应包括植物轴的迅速延长、叶片发育不良和早花[1，2]。这些表型与植物对植物遮荫威胁的反应类似，并已被证明与激素生长素有关[1，3]。在这项工作中，我们证明了高温诱导的结构适应是通过bHLH转录调节因子光敏色素相互作用因子4(PIF4)介导的。PIF4在光信号和赤霉素(GA)信号中的作用已经确定，分别通过与光敏色素和Della蛋白的相互作用[4-6]。缺乏PIF4的突变体在转移到高温时不会表现出伸长反应或叶片发育不良。高温诱导的生长素反应基因IAA29在这些植物中也被取消。在PIF4突变体中，对高温的早期开花反应保持不变，这表明构筑反应和开花反应是通过不同的信号途径进行的。然而，PIF4在温度信号中的作用似乎并不是通过与光敏色素或Della蛋白的相互作用来实现的，这表明存在一种新的调节机制。我们认为，PIF4是植物高温信号的重要组成部分，在植物发育过程中整合了多种环境信号。
Exposure of Arabidopsis plants to high temperature (28 degrees C) results in a dramatic change in plant development. Responses to high temperature include rapid extension of plant axes, leaf hyponasty, and early flowering [1, 2]. These phenotypes parallel plant responses to the threat of vegetational shade and have been shown to involve the hormone auxin [1, 3]. In this work, we demonstrate that high temperature-induced architectural adaptations are mediated through the bHLH transcriptional regulator PHYTOCHROME INTERACTING FACTOR 4 (PIF4). Roles for PIF4 have previously been established in both light and gibberellin (GA) signaling, through interactions with phytochromes and DELLA proteins, respectively [4-6]. Mutants deficient in PIF4 do not display elongation responses or leaf hyponasty upon transfer to high temperature. High temperature-mediated induction of the auxin-responsive gene IAA29 is also abolished in these plants. An early flowering response to high temperature is maintained in pif4 mutants, suggesting that architectural and flowering responses operate via separate signaling pathways. The role of PIF4 in temperature signaling does not, however, appear to operate through interaction with either phytochrome or DELLA proteins, suggesting the existence of a novel regulatory mechanism. We conclude that PIF4 Is an important component of plant high temperature signaling and integrates multiple environmental cues during plant development.