Brassinosteroid Signaling Regulates Leaf Erectness in Oryza sativa via the Control of a Specific U-Type Cyclin and Cell Proliferation
Brassinosteroid Signaling Regulates Leaf Erectness in Oryza sativa via the Control of a Specific U-Type Cyclin and Cell Proliferation
复制标题
油菜素类固醇信号通过控制特定的 U 型细胞周期蛋白和细胞增殖来调节水稻叶片的直立度
DOI：
10.1016/j.devcel.2015.05.019
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发表时间：
2015-07-27
影响因子：
11.8
通讯作者：
Wang, Xuelu
中科院分区：
文献类型：
--
作者：
Sun, Shiyong;Chen, Donghong;Wang, Xuelu
叶片的直立性是决定植物结构和产量的关键，尤其是谷类作物。油菜素内酯（BRs）在单子房植物的这一特性中起着独特的控制作用，但其潜在的细胞和分子机制仍是一个谜。本研究发现，水稻叶片节理（lamina joint, LJs）的背面厚壁组织细胞数量与叶片的直立性密切相关，而BR信号则对其增殖有着密切的调控作用。我们鉴定了一个水稻u型细胞周期蛋白CYC U4；1在水稻LJ中富集，其表达伴随着LJ的发育。遗传和生化研究表明，CYC U4；1通过控制叶片背面厚壁组织细胞的增殖，起到促进叶片直立的积极作用。此外，BR信号通过协调调节cycu4抑制下壁厚组织细胞分裂；1通过BES1和CYC U4表达；1蛋白活性通过GSK3激酶。这些结果支持细胞周期蛋白cycu4的关键作用；1介导br调控的细胞分裂控制叶片直立。
Leaf erectness is key in determining plant architecture and yield, particularly in cereal crops. Brassinosteroids (BRs) play a unique role in controlling this trait in monocots, but the underlying cellular and molecular mechanisms remain big mysteries. Here we report that the abaxial sclerenchyma cell number of rice lamina joints (LJs) is closely related to leaf erectness, and BR signaling tightly regulates their proliferation. We identified a rice U-type cyclin CYC U4;1 enriched in rice LJs, with its expression accompanying LJ development. Genetic and biochemical studies demonstrated that CYC U4; 1 plays a positive role in promoting leaf erectness by controlling the abaxial sclerenchyma cell proliferation. Furthermore, BR signaling inhibits the abaxial sclerenchyma cell division by coordinately regulating CYC U4; 1 expression through BES1 and CYC U4; 1 protein activity through GSK3 kinases. These results support a key role of the cyclin CYC U4; 1 in mediating BR-regulated cell division to control leaf erectness.