PCH1 regulates light, temperature, and circadian signaling as a structural component of phytochrome B-photobodies in Arabidopsis
PCH1 regulates light, temperature, and circadian signaling as a structural component of phytochrome B-photobodies in Arabidopsis
复制标题
DOI：
10.1073/pnas.1818217116
复制
发表时间：
2019-04-23
影响因子：
11.1
通讯作者：
Nusinow, Dmitri A.
中科院分区：
文献类型：
--
作者：
Huang, He;McLoughlin, Katrice E.;Nusinow, Dmitri A.
光敏色素（phytochrome，phy）家族的成员是植物光形态建成的主要调节剂，其独特的能力是在生物学上无活性的吸收红光的Pr状态和活性的吸收远红光的Pfr状态之间进行光互变。虽然Pfr信号传导的初始步骤尚不清楚，但phyB亚型在光转化后的早期事件是其从细胞质重新分布到被称为光体（PB）的亚核病灶中，在Pfr通过远红外辐射或温度依赖性非光化学逆转恢复为Pr后，这些病灶消失。在这里，我们提出的证据表明，光周期控制下胚轴1（PCH1）功能作为一个重要的结构组成部分phyB含PB和作为一个直接调节器的热逆转，足以稳定phyB作为PFR在体外。通过研究组成型活性phyB（Y276 H）-YFP等位基因（YHB-YFP）和PCH1之间的遗传相互作用，我们发现PCH1的缺失阻止YHB合并成PB而不影响其核定位，而PCH1的过表达显著增加PB水平。PCH1的损失，大概是通过影响phyB-PB组装，妥协的一些事件引起的YHB-YFP植物，包括其组成的光形态发生表型，红光调节的热形态发生，并输入phyB到生物钟。相反，phyB和PCH 1水平升高会产生稳定的远红光可逆PB，持续数天。总的来说，我们的数据表明，含有PCH1的PB的组装是关键的phyB信号多个输出，并建议改变PB的动态可以用来调节植物对光和温度的反应。
The members of the phytochrome (phy) family of bilin-containing photoreceptors are major regulators of plant photomorphogenesis through their unique ability to photointerconvert between a biologically inactive red light-absorbing Pr state and an active farred light-absorbing Pfr state. While the initial steps in Pfr signaling are unclear, an early event for the phyB isoform after photoconversion is its redistribution from the cytoplasm into subnuclear foci known as photobodies (PBs), which dissipate after Pfr reverts back to Pr by far-red irradiation or by temperature-dependent nonphotochemical reversion. Here we present evidence that PHOTOPERIODIC CONTROL OF HYPOCOTYL 1 (PCH1) functions both as an essential structural component of phyB-containing PBs and as a direct regulator of thermal reversion that is sufficient to stabilize phyB as Pfr in vitro. By examining the genetic interaction between a constitutively active phyB(Y276H)-YFP allele (YHB-YFP) and PCH1, we show that the loss of PCH1 prevents YHB from coalescing into PBs without affecting its nuclear localization, whereas overexpression of PCH1 dramatically increases PB levels. Loss of PCH1, presumably by impacting phyB-PB assembly, compromises a number of events elicited in YHB-YFP plants, including their constitutive photomorphogenic phenotype, red light-regulated thermomorphogenesis, and input of phyB into the circadian clock. Conversely, elevated levels of both phyB and PCH1 generate stable, yet far-red light-reversible PBs that persisted for days. Collectively, our data demonstrate that the assembly of PCH1-containing PBs is critical for phyB signaling to multiple outputs and suggest that altering PB dynamics could be exploited to modulate plant responses to light and temperature.