NCP1/AtMOB1A Plays Key Roles in Auxin-Mediated Arabidopsis Development.
NCP1/AtMOB1A Plays Key Roles in Auxin-Mediated Arabidopsis Development.
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DOI：
10.1371/journal.pgen.1005923
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发表时间：
2016-03
期刊：
影响因子：
4.5
通讯作者：
Cheng Y
中科院分区：
文献类型：
--
作者：
Cui X;Guo Z;Song L;Wang Y;Cheng Y
MOB1蛋白是动物Hippo信号通路的核心组分，参与控制组织生长和肿瘤抑制。植物MOB1蛋白序列与动物MOB1蛋白具有较高的同源性，但其在植物生长发育中的作用尚不清楚。本文中，我们报道了拟南芥中MOB1 （AtMOB1A）在生长素介导的拟南芥发育中的关键作用。我们发现，当AtMOB1A的功能缺失突变与PINOID （PID）的突变结合时，完全消除了子叶的形成，PINOID编码参与生长素信号传导和运输的丝氨酸/苏氨酸蛋白激酶。我们发现atmob1a完全被果蝇的对应物拯救，这表明功能守恒。atmob1a pid双突变体表型上表现出几个在生长素生物合成或运输方面有缺陷的突变体组合。此外，我们证明了atmob1a极大地增强了其他几种已知的生长素突变体，这表明atmob1a在生长素介导的植物发育中起着关键作用。与野生型相比，atmob1a单突变体在早期胚胎发生中表现出缺陷，根短，花小。在胚胎发生过程中，AtMOB1A在胚胎和胚柄细胞中均有表达，这与其在胚胎发育中的作用是一致的。AtMOB1A蛋白定位于细胞核、细胞质，并与质膜相关，提示其在这些亚细胞定位中发挥作用。此外，我们发现AtMOB1A的破坏导致对外源性生长素的敏感性降低。我们的研究结果表明，AtMOB1A通过促进生长素信号传导在拟南芥发育中发挥重要作用。MOB1蛋白是动物Hippo信号通路的关键组分，在器官大小控制中起关键作用。植物激素生长素调节植物生长发育的许多方面，包括器官发生。在这项工作中，我们发现与动物MOB1蛋白高度同源的AtMOB1A在植物器官发生中发挥重要作用。此外，我们证明了AtMOB1A与生长素的生物合成、运输和信号通路协同作用，以调节拟南芥的发育。我们进一步证明AtMOB1A可能通过促进生长素信号传导来控制植物发育。本研究发现了生长素介导植物发育的新机制，为进一步研究生长素调控植物器官发生的机制奠定了基础。
MOB1 protein is a core component of the Hippo signaling pathway in animals where it is involved in controlling tissue growth and tumor suppression. Plant MOB1 proteins display high sequence homology to animal MOB1 proteins, but little is known regarding their role in plant growth and development. Herein we report the critical roles of Arabidopsis MOB1 (AtMOB1A) in auxin-mediated development in Arabidopsis. We found that loss-of-function mutations in AtMOB1A completely eliminated the formation of cotyledons when combined with mutations in PINOID (PID), which encodes a Ser/Thr protein kinase that participates in auxin signaling and transport. We showed that atmob1a was fully rescued by its Drosophila counterpart, suggesting functional conservation. The atmob1a pid double mutants phenocopied several well-characterized mutant combinations that are defective in auxin biosynthesis or transport. Moreover, we demonstrated that atmob1a greatly enhanced several other known auxin mutants, suggesting that AtMOB1A plays a key role in auxin-mediated plant development. The atmob1a single mutant displayed defects in early embryogenesis and had shorter root and smaller flowers than wild type plants. AtMOB1A is uniformly expressed in embryos and suspensor cells during embryogenesis, consistent with its role in embryo development. AtMOB1A protein is localized to nucleus, cytoplasm, and associated to plasma membrane, suggesting that it plays roles in these subcellular localizations. Furthermore, we showed that disruption of AtMOB1A led to a reduced sensitivity to exogenous auxin. Our results demonstrated that AtMOB1A plays an important role in Arabidopsis development by promoting auxin signaling. MOB1 protein is a key component of the Hippo signaling pathway in animals, and it plays critical roles in organ size control. The plant hormone auxin regulates many aspects of plant growth and development including organogenesis. In this work, we showed that AtMOB1A, which is highly homologous to animal MOB1 proteins, plays an important role in plant organogenesis. Furthermore, we demonstrated that AtMOB1A synergistically interacts with auxin biosynthesis, transport, and signaling pathways to regulate Arabidopsis development. We further showed that AtMOB1A likely controls plant development by promoting auxin signaling. This work identified a new player in auxin-mediated plant development and lays a foundation for further dissection of the mechanisms by which auxin regulates organogenesis.