title: STIMPY mediates cytokinin signaling during shoot meristem establishment in Arabidopsis seedlings.
abstract: The establishment of the primary meristems through proliferation after germination is essential for plant post-embryonic development. Cytokinins have long been considered a key regulator of plant cell division. Here we show that cytokinins are essential for early seedling development of Arabidopsis. Loss of cytokinin perception leads to a complete failure of meristem establishment and growth arrest after germination. We also present evidence that cytokinin signaling is involved in activation of the homeobox gene STIMPY (STIP or WOX9) expression in meristematic tissues, which is essential for maintaining the meristematic fate. Cytokinin-independent STIP expression is able to partially compensate for the shoot apical meristem growth defects in mutants that cannot sense cytokinin. These findings identify a new branch of the cytokinin signaling network, linking cytokinin to the process of meristem and seedling establishment.
authors.affiliation: Molecular and Computational Biology, University of Southern California, Los Angeles, CA 90089, USA.
authors.forename: Anna
authors.initials: A
authors.lastname: Skylar
authors.forename: Fangxin
authors.initials: F
authors.lastname: Hong
authors.forename: Joanne
authors.initials: J
authors.lastname: Chory
authors.forename: Detlef
authors.initials: D
authors.lastname: Weigel
authors.forename: Xuelin
authors.initials: X
authors.lastname: Wu
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000502:physiology*; D001483:Base Sequence; D003583:Cytokinins / Q000502:physiology*; D017931:DNA Primers / Q000235:genetics; D025461:Feedback, Physiological; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D005801:Genes, Homeobox; D017343:Genes, Plant; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology*; D018519:Meristem / Q000254:growth & development; D008954:Models, Biological; D009154:Mutation; D030821:Plants, Genetically Modified; D036226:Seedlings / Q000254:growth & development; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; D003583:Cytokinins; D017931:DNA Primers; D018398:Homeodomain Proteins; C500834:STIMPY protein, Arabidopsis