title: The Arabidopsis Receptor Kinase ZAR1 Is Required for Zygote Asymmetric Division and Its Daughter Cell Fate.
abstract: Asymmetric division of zygote is critical for pattern formation during early embryogenesis in plants and animals. It requires integration of the intrinsic and extrinsic cues prior to and/or after fertilization. How these cues are translated into developmental signals is poorly understood. Here through genetic screen for mutations affecting early embryogenesis, we identified an Arabidopsis mutant, zygotic arrest 1 (zar1), in which zygote asymmetric division and the cell fate of its daughter cells were impaired. ZAR1 encodes a member of the RLK/Pelle kinase family. We demonstrated that ZAR1 physically interacts with Calmodulin and the heterotrimeric G protein Gβ, and ZAR1 kinase is activated by their binding as well. ZAR1 is specifically expressed micropylarly in the embryo sac at eight-nucleate stage and then in central cell, egg cell and synergids in the mature embryo sac. After fertilization, ZAR1 is accumulated in zygote and endosperm. The disruption of ZAR1 and AGB1 results in short basal cell and an apical cell with basal cell fate. These data suggest that ZAR1 functions as a membrane integrator for extrinsic cues, Ca2+ signal and G protein signaling to regulate the division of zygote and the cell fate of its daughter cells in Arabidopsis.
authors.affiliation: State Key Laboratory of Molecular Developmental Biology, National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Tian-Ying
authors.initials: TY
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Molecular Developmental Biology, National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Dong-Qiao
authors.initials: DQ
authors.lastname: Shi
authors.affiliation: State Key Laboratory of Molecular Developmental Biology, National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Peng-Fei
authors.initials: PF
authors.lastname: Jia
authors.affiliation: State Key Laboratory of Molecular Developmental Biology, National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Tang
authors.affiliation: State Key Laboratory of Molecular Developmental Biology, National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Hong-Ju
authors.initials: HJ
authors.lastname: Li
authors.affiliation: State Key Laboratory of Molecular Developmental Biology, National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Molecular Developmental Biology, National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Wei-Cai
authors.initials: WC
authors.lastname: Yang
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D060049:Asymmetric Cell Division / Q000235:genetics*; D020013:Calcium Signaling; D002147:Calmodulin / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics; D047108:Embryonic Development / Q000235:genetics*; D056625:Endosperm / Q000235:genetics / Q000378:metabolism; D044387:GTP-Binding Protein beta Subunits / Q000235:genetics* / Q000378:metabolism; D015053:Zygote / Q000254:growth & development; D047908:Intracellular Signaling Peptides and Proteins
chemical_list: D029681:Arabidopsis Proteins; D002147:Calmodulin; D002352:Carrier Proteins; D044387:GTP-Binding Protein beta Subunits; C089590:AGB1 protein, Arabidopsis; C551312:ZAR1 protein, Arabidopsis; D047908:Intracellular Signaling Peptides and Proteins