title: NCP1/AtMOB1A Plays Key Roles in Auxin-Mediated Arabidopsis Development.
abstract: 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.
authors.affiliation: Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China.|University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Xiaona
authors.initials: X
authors.lastname: Cui
authors.affiliation: Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China.
authors.forename: Zhiai
authors.initials: Z
authors.lastname: Guo
authors.affiliation: Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China.
authors.forename: Lizhen
authors.initials: L
authors.lastname: Song
authors.affiliation: Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China.|University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China.
authors.forename: Youfa
authors.initials: Y
authors.lastname: Cheng
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000096:biosynthesis* / Q000235:genetics; D018797:Cell Cycle Proteins / Q000096:biosynthesis* / Q000235:genetics; D035264:Flowers / Q000235:genetics / Q000254:growth & development; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism* / Q000494:pharmacology; D009154:Mutation; D063245:Plant Development / Q000235:genetics*; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; D018797:Cell Cycle Proteins; D007210:Indoleacetic Acids; C000589223:Mob1A protein, Arabidopsis thaliana