title: The EVERSHED receptor-like kinase modulates floral organ shedding in Arabidopsis.
abstract: Plant cell signaling triggers the abscission of entire organs, such as fruit, leaves and flowers. Previously, we characterized an ADP-ribosylation factor GTPase-activating protein, NEVERSHED (NEV), that regulates membrane trafficking and is essential for floral organ shedding in Arabidopsis. Through a screen for mutations that restore organ separation in nev flowers, we have identified a leucine-rich repeat receptor-like kinase, EVERSHED (EVR), that functions as an inhibitor of abscission. Defects in the Golgi structure and location of the trans-Golgi network in nev abscission zone cells are rescued by a mutation in EVR, suggesting that EVR might regulate membrane trafficking during abscission. In addition to shedding their floral organs prematurely, nev evr flowers show enlarged abscission zones. A similar phenotype was reported for plants ectopically expressing INFLORESCENCE DEFICIENT IN ABSCISSION, a predicted signaling ligand for the HAESA/HAESA-LIKE2 receptor-like kinases, indicating that this signaling pathway may be constitutively active in nev evr flowers. We present a model in which EVR modulates the timing and region of abscission by promoting the internalization of other receptor-like kinases from the plasma membrane.
authors.affiliation: Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, NC 27599, USA.
authors.forename: Michelle E
authors.initials: ME
authors.lastname: Leslie
authors.forename: Michael W
authors.initials: MW
authors.lastname: Lewis
authors.forename: Ji-Young
authors.initials: JY
authors.lastname: Youn
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Daniels
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Liljegren
mesh_terms: D017360:Arabidopsis / Q000502:physiology; D029681:Arabidopsis Proteins / Q000502:physiology*; D035264:Flowers / Q000254:growth & development*; D020690:GTPase-Activating Proteins; D011494:Protein Kinases / Q000378:metabolism / Q000502:physiology*; D021381:Protein Transport; D011956:Receptors, Cell Surface / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D020690:GTPase-Activating Proteins; C544765:NEV protein, Arabidopsis; D011956:Receptors, Cell Surface; D011494:Protein Kinases