Brassinosteroids regulate organ boundary formation in the shoot apical meristem of Arabidopsis
Brassinosteroids regulate organ boundary formation in the shoot apical meristem of Arabidopsis
复制标题
DOI：
10.1073/pnas.1210799110
复制
发表时间：
2012-12-18
影响因子：
11.1
通讯作者：
Wang, Zhi-Yong
中科院分区：
文献类型：
--
作者：
Gendron, Joshua M.;Liu, Jiang-Shu;Wang, Zhi-Yong
顶端分生组织(SAM)中干细胞生态位对器官原基和器官边界形成的时空控制决定了植物的构型和构型，但其潜在的信号机制仍然知之甚少。在这里，我们表明油菜素类固醇(BRs)通过抑制器官边界识别基因在器官边界形成中发挥关键作用。BR-超敏突变体表现为器官融合表型，而bR-不敏感突变体表现为器官边界增强。BR激活的转录因子BZR1直接抑制器官边界识别基因的杯状子叶(CUC)家族。在WT植物中，BZR1在中央分生组织和器官原基的细胞核中高水平积累，但在器官边界细胞中低水平积累，从而允许CUC基因的表达。BR信号的激活抑制了CUC基因的表达，并导致器官融合表型。这项研究揭示了BR在SAM中器官边界形成和形态发生的时空控制中的作用。
Spatiotemporal control of the formation of organ primordia and organ boundaries from the stem cell niche in the shoot apical meristem (SAM) determines the patterning and architecture of plants, but the underlying signaling mechanisms remain poorly understood. Here we show that brassinosteroids (BRs) play a key role in organ boundary formation by repressing organ boundary identity genes. BR-hypersensitive mutants display organ-fusion phenotypes, whereas BR-insensitive mutants show enhanced organ boundaries. The BR-activated transcription factor BZR1 directly represses the CUP-SHAPED COTYLEDON (CUC) family of organ boundary identity genes. In WT plants, BZR1 accumulates at high levels in the nuclei of central meristem and organ primordia but at a low level in organ boundary cells to allow CUC gene expression. Activation of BR signaling represses CUC gene expression and causes organ fusion phenotypes. This study uncovers a role for BR in the spatiotemporal control of organ boundary formation and morphogenesis in the SAM.