Strigolactones and Brassinosteroids Antagonistically Regulate the Stability of the D53-OsBZR1 Complex to Determine FC1 Expression in Rice Tillering
Strigolactones and Brassinosteroids Antagonistically Regulate the Stability of the D53-OsBZR1 Complex to Determine FC1 Expression in Rice Tillering
复制标题
独脚金内酯和油菜素类固醇拮抗调节D53-OsBZR1复合物的稳定性以确定水稻分蘖中FC1的表达
DOI：
10.1016/j.molp.2019.12.005
复制
发表时间：
2020-04-06
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：
Fang, Zhongming;Ji, Yuanyuan;Wang, Xuelu
水稻分蘖是决定产量的一个重要结构性状，受一类新发现的植物激素独脚金内酯（SL）的高度调控。然而，从受体到下游转录因子最终抑制分蘖的整个SL信号通路仍然没有被揭示。在本研究中，我们首次发现油菜素甾醇（BR）通过促进芽的生长而强烈地增强水稻的分蘖，这与拟南芥中BR的功能有很大不同。遗传和生化分析表明，SL和BR信号途径均通过调节D53和/或水稻BR信号途径中的转录复合体OsBZR 1-RLA 1-DLT模块的稳定性来控制水稻分蘖。我们进一步发现，D53与OsBZR 1相互作用，以抑制FC 1的表达，一个分蘖的局部抑制剂，这种抑制依赖于直接DNA结合OsBZR 1，招募D53的FC 1启动子在水稻芽。综上所述，这些发现揭示了SL和BR如何通过早期反应基因FC 1协调调节水稻分蘖的机制。
Rice tillering, a key architecture trait determining grain yield, is highly regulated by a class of newly identified phytohormones, strigolactones (SLs). However, the whole SL signaling pathway from the receptor to downstream transcription factors to finally inhibit tillering remains unrevealed. In this study, we first found that brassinosteroids (BRs) strongly enhance tillering by promoting bud outgrowth in rice, which is largely different from the function of BRs in Arabidopsis. Genetic and biochemical analyses indicated that both the SL and BR signaling pathways control rice tillering by regulating the stability of D53 and/or the OsBZR1-RLA1-DLT module, a transcriptional complex in the rice BR signaling pathway. We further found that D53 interacts with OsBZR1 to inhibit the expression of FC1, a local inhibitor of tillering, and that this inhibition depends on direct DNA binding by OsBZR1, which recruits D53 to the FC1 promoter in rice buds. Taken together, these findings uncover a mechanism illustrating how SLs and BRs coordinately regulate rice tillering via the early responsive gene FC1.