The Arabidopsis circadian clock protein PRR5 interacts with and stimulates ABI5 to modulate abscisic acid signaling during seed germination.
The Arabidopsis circadian clock protein PRR5 interacts with and stimulates ABI5 to modulate abscisic acid signaling during seed germination.
复制标题
拟南芥生物钟蛋白 PRR5 与 ABI5 相互作用并刺激 ABI5 在种子萌发过程中调节脱落酸信号传导
DOI：
10.1093/plcell/koab168
复制
发表时间：
2021-09-24
期刊：
影响因子：
--
通讯作者：
Hu Y
中科院分区：
文献类型：
--
作者：
Yang M;Han X;Yang J;Jiang Y;Hu Y
种子萌发和萌发后的生长需要多种内在和环境信号的精确协调。植物激素脱落酸（阿坝）抑制拟南芥中的这些过程，昼夜节律钟有助于阿坝信号的调节。然而，昼夜节律钟介导的阿坝信号转导的分子机制在很大程度上仍然未知。在这里，我们发现，核心生物钟蛋白质PRR5和PRR7与阿坝信号传导的关键转录因子ABI5物理相关。PRR5和PRR7在种子萌发过程中冗余地正向调节阿坝信号。同时破坏PRR5和PRR7使萌发的种子对阿坝不敏感，而PRR5的过表达增强阿坝信号，抑制种子萌发。与此相一致的是，几个ABA反应基因的表达被PRR蛋白上调。遗传分析表明PRR5主要依赖ABI5促进阿坝信号传导。进一步的机制研究表明PRR5刺激ABI5的转录功能而不影响其稳定性。总的来说，我们的研究结果表明，这些PRR蛋白的功能与ABI5协同激活阿坝反应在种子萌发过程中，从而提供了一个机械的理解阿坝信号和昼夜节律钟是如何直接集成通过转录复合物，涉及ABI5和中央昼夜节律钟组件。
Abstract Seed germination and postgerminative growth require the precise coordination of multiple intrinsic and environmental signals. The phytohormone abscisic acid (ABA) suppresses these processes in Arabidopsis thaliana and the circadian clock contributes to the regulation of ABA signaling. However, the molecular mechanism underlying circadian clock-mediated ABA signaling remains largely unknown. Here, we found that the core circadian clock proteins PSEUDO-RESPONSE REGULATOR5 (PRR5) and PRR7 physically associate with ABSCISIC ACID-INSENSITIVE5 (ABI5), a crucial transcription factor of ABA signaling. PRR5 and PRR7 positively modulate ABA signaling redundantly during seed germination. Disrupting PRR5 and PRR7 simultaneously rendered germinating seeds hyposensitive to ABA, whereas the overexpression of PRR5 enhanced ABA signaling to inhibit seed germination. Consistent with this, the expression of several ABA-responsive genes is upregulated by PRR proteins. Genetic analysis demonstrated that PRR5 promotes ABA signaling mainly dependently on ABI5. Further mechanistic investigation revealed that PRR5 stimulates the transcriptional function of ABI5 without affecting its stability. Collectively, our results indicate that these PRR proteins function synergistically with ABI5 to activate ABA responses during seed germination, thus providing a mechanistic understanding of how ABA signaling and the circadian clock are directly integrated through a transcriptional complex involving ABI5 and central circadian clock components.
登录
查看更多内容
影响因子：
7.4
作者：
Brocard, IM;Lynch, TJ;Finkelstein, RR
通讯作者：
Finkelstein, RR
影响因子：
5.1
作者：
Finkelstein, R;Gampala, SSL;Rock, CD
通讯作者：
Rock, CD
影响因子：
7.2
作者：
FINKELSTEIN, RR
通讯作者：
FINKELSTEIN, RR
影响因子：
12.3
作者：
Covington, Michael F.;Maloof, Julin N.;Straume, Marty;Kay, Steve A.;Harmer, Stacey L.
通讯作者：
Harmer, Stacey L.
影响因子：
9.4
作者：
Adams, Sally;Grundy, Jack;Carre, Isabelle A.
通讯作者：
Carre, Isabelle A.