Abscisic Acid Signaling Inhibits Brassinosteroid Signaling through Dampening the Dephosphorylation of BIN2 by ABI1 and ABI2
Abscisic Acid Signaling Inhibits Brassinosteroid Signaling through Dampening the Dephosphorylation of BIN2 by ABI1 and ABI2
复制标题
脱落酸信号传导通过抑制 ABI1 和 ABI2 对 BIN2 的去磷酸化来抑制油菜素类固醇信号传导
DOI：
10.1016/j.molp.2017.12.013
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发表时间：
2018-02-05
期刊：
影响因子：
27.5
通讯作者：
Wang, Xuelu
中科院分区：
文献类型：
--
作者：
Wang, Haijiao;Tang, Jie;Wang, Xuelu
脱落酸（阿坝）和油菜素类固醇（BR）拮抗调节植物生长发育的许多方面。以前的生理研究表明，阿坝对BR信号的抑制在很大程度上依赖于ABI 1和ABI 2。然而，ABI 1和ABI 2如何参与抑制BR信号传导的遗传和分子基础仍不清楚。虽然已知在BR信号传导途径中ABA-BR串扰发生在BR受体复合物的下游但在BR信号传导的负调节因子BIN 2激酶的上游，但是充当直接介导其串扰的枢纽的组分仍然是一个很大的谜。在这里，我们发现ABI 1和ABI 2与BIN 2相互作用并使其去磷酸化，以调节其对BES 1磷酸化的活性。通过体外模拟阿坝信号转导，我们发现阿坝可以通过阿坝受体抑制ABI 2，从而促进BIN 2的磷酸化。RNA测序分析进一步表明，阿坝抑制BR信号通过阿坝的主要信号成分，包括其受体和ABI 2，和阿坝和GSK 3s共调节一组共同的压力响应基因。由于BIN 2可以与SnRK 2s相互作用并磷酸化以激活其激酶活性，我们的研究还揭示了阿坝信号通路中存在PP 2Cs-BIN 2-SnRK 2s模块。总的来说，这些研究结果提供了重要的见解，植物如何平衡生长和生存协调调节促进生长的信号通路和非生物胁迫下的胁迫反应。
Abscisic acid (ABA) and brassinosteroid (BR) antagonistically regulate many aspects of plant growth and development. Previous physiological studies have revealed that the inhibition of BR signaling by ABA is largely dependent on ABI1 and ABI2. However, the genetic and molecular basis of how ABI1 and ABI2 are involved in inhibiting BR signaling remains unclear. Although it is known that in the BR signaling pathway the ABA-BR crosstalk occurs in the downstream of BR receptor complex but upstream of BIN2 kinase, a negative regulator of BR signaling, the component that acts as the hub to directly mediate their crosstalk remains a big mystery. Here, we found that ABI1 and ABI2 interact with and dephosphorylate BIN2 to regulate its activity toward the phosphorylation of BES1. By in vitro mimicking ABA signal transduction, we found that ABA can promote BIN2 phosphorylation by inhibiting ABI2 through ABA receptors. RNA-sequencing analysis further demonstrated that ABA inhibits BR signaling through the ABA primary signaling components, including its receptors and ABI2, and that ABA and GSK3s co-regulate a common set of stress-responsive genes. Because BIN2 can interact with and phosphorylate SnRK2s to activate its kinase activity, our study also reveals there is a module of PP2Cs-BIN2-SnRK2s in the ABA signaling pathway. Collectively, these findings provide significant insights into how plants balance growth and survival by coordinately regulating the growth-promoting signaling pathway and stress responses under abiotic stresses.