Introduction

Increasing ambient temperature within the physiological, nonstressful, range promotes the growth of the hypocotyl (Gray et al., 1998) and of the primary root (Hanzawa et al., 2013), whilst reducing the expansion of the cotyledons (Hahm et al., 2020) of Arabidopsis thaliana seedlings.

We currently know three thermosensors, phytochrome B (phyB) (Jung et al., 2016; Legris et al., 2016), EARLY FLOWERING 3 (ELF3) (Jung et al., 2020) and PHYTOCHROME INTERACTING FACTOR 7 (PIF7) (Chung et al., 2020), which were uncovered by their role in the control of hypocotyl growth. phyB is a photosensory receptor, activated by red light and inactivated by far-red light, and a thermosensor by virtue of the instability of its active form, undergoing thermal reversion to its inactive conformer accelerated by warmth (Jung et al., 2016; Legris et al., 2016; Burgie et al., 2021). ELF3 is a transcriptional regulator that integrates the evening complex; warm temperatures reduce the association of this complex to the target gene promoters (Box et al., 2015; Ezer et al., 2017; Silva et al., 2020) by eliciting ELF3 phase transition from the active to the inactive state (Jung et al., 2020). PIF7 is a transcription factor and warm temperatures modify the structure of the RNA hairpin present at the 5′-untranslated region of the PIF7 transcript, increasing its rate of translation and therefore increasing PIF7 protein abundance (Chung et al., 2020; Fiorucci et al., 2020). In summary, warm temperatures reduce the activities of phyB and ELF3, whilst increasing that of PIF7. Both phyB and ELF3 repress hypocotyl growth and are active at control temperatures; therefore, the phyB and elf3 mutants have elongated hypocotyls at control temperatures. Conversely, PIF7 promotes hypocotyl growth and its activity increases at warm temperatures; therefore, the pif7 mutant has a short hypocotyl at warm temperatures.

The root captures water and nutrients and provides an anchorage to the soil. Given these crucial functions, there is a growing interest in understanding the mechanisms involved in the control of primary root elongation by temperature (Hanzawa et al., 2013; Wang et al., 2016; Ibañez et al., 2017; Martins et al., 2017; Yang et al., 2017; Zhu et al., 2018; Fei et al., 2019; Feraru et al., 2019; Gaillochet et al., 2020; Fonseca de Lima et al., 2021; Lee et al., 2021). The aim of this work was to investigate whether the shoot thermosensors phyB, EFL3 and PIF7 fulfil the same function in the root.

中文翻译：

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射击温度传感器在根部不具备相同的功能

介绍

在生理、无压力范围内提高环境温度可促进下胚轴 (Gray et al .,  1998 ) 和初生根 (Hanzawa et al .,  2013 ) 的生长，同时减少子叶的扩张 (Hahm et al ., 2013) 。 ,  2020 )拟南芥幼苗。

我们目前知道三种热传感器，光敏色素 B (phyB) (Jung et al ., 2016 ; Legris et al ., 2016 ), EARLY FLOWERING 3 (ELF3) (Jung et al ., 2020 ) 和 PHYTOCHROME INTERACTING FACTOR 7 (PIF7) ( Chung et al .,  2020 )，发现它们在控制下胚轴生长中的作用。phyB 是一种光感应受体，被红光激活，被远红光灭活，并且是一种热传感器，由于其活性形式的不稳定性，在温度的作用下经历热恢复到其非活性构象体（Jung等人，  2016 年；Legris等人， 2016 年；Burgie等人，  2021 年）。ELF3是整合晚间复合物的转录调节剂；温暖的温度通过引发ELF3从活性状态到非活性状态的相变（Jung等人， 2017 年；Silva等人，  2020 年）减少了这种复合物与靶基因启动子的关联 等，  2020 年）。PIF7 是一种转录因子，温暖的温度会改变存在于PIF7 5'-非翻译区的 RNA 发夹结构转录本，提高其翻译率，从而增加 PIF7 蛋白丰度（Chung等人，  2020 年；Fiorucci等人，  2020 年）。总之，温暖的温度会降低 phyB 和 ELF3 的活性，同时增加 PIF7 的活性。phyB 和 ELF3 都抑制下胚轴生长并在控制温度下活跃；因此，phyB和elf3突变体在控制温度下具有伸长的下胚轴。相反，PIF7 促进下胚轴生长，其活性在温暖的温度下增加；因此，pif7突变体在温暖的温度下具有短的下胚轴。

根部捕获水分和养分，并为土壤提供锚固。鉴于这些关键功能，人们越来越有兴趣了解温度控制主根伸长所涉及的机制（Hanzawa等人，  2013 年；Wang等人，  2016 年；Ibañez等人，  2017 年；Martins等人。 ,  2017 ; Yang等人, 2017 ; Zhu等人, 2018 ; Fei等人, 2019 ; Feraru等人, 2019 ; Gaillochet等人., 2020 ; 丰塞卡德利马等人，2021 年；李等人，  2021 年）。这项工作的目的是调查芽热传感器 phyB、EFL3 和 PIF7 是否在根中发挥相同的功能。