title: Dysregulation of cell-to-cell connectivity and stomatal patterning by loss-of-function mutation in Arabidopsis chorus (glucan synthase-like 8).
abstract: Patterning of stomata, valves on the plant epidermis, requires the orchestrated actions of signaling components and cell-fate determinants. To understand the regulation of stomatal patterning, we performed a genetic screen using a background that partially lacks stomatal signaling receptors. Here, we report the isolation and characterization of chorus (chor), which confers excessive proliferation of stomatal-lineage cells mediated by SPEECHLESS (SPCH). chor breaks redundancy among three ERECTA family genes and strongly enhances stomatal patterning defects caused by loss-of-function in TOO MANY MOUTHS. chor seedlings also exhibit incomplete cytokinesis and growth defects, including disruptions in root tissue patterning and root hair cell morphogenesis. CHOR encodes a putative callose synthase, GLUCAN SYNTHASE-LIKE 8 (GSL8), that is required for callose deposition at the cell plate, cell wall and plasmodesmata. Consistently, symplastic macromolecular diffusion between epidermal cells is significantly increased in chor, and proteins that do not normally move cell-to-cell, including a fluorescent protein-tagged SPCH, diffuse to neighboring cells. Such a phenotype is not a general trait caused by cytokinesis defects. Our findings suggest that the restriction of symplastic movement might be an essential step for the proper segregation of cell-fate determinants during stomatal development.
authors.affiliation: Department of Biology, University of Washington, Seattle, WA 98195, USA.
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Guseman
authors.forename: Jin Suk
authors.initials: JS
authors.lastname: Lee
authors.forename: Naomi L
authors.initials: NL
authors.lastname: Bogenschutz
authors.forename: Kylee M
authors.initials: KM
authors.lastname: Peterson
authors.forename: Rebecca E
authors.initials: RE
authors.lastname: Virata
authors.forename: Bo
authors.initials: B
authors.lastname: Xie
authors.forename: Masahiro M
authors.initials: MM
authors.lastname: Kanaoka
authors.forename: Zonglie
authors.initials: Z
authors.lastname: Hong
authors.forename: Keiko U
authors.initials: KU
authors.lastname: Torii
mesh_terms: D017360:Arabidopsis / Q000196:embryology / Q000201:enzymology / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000502:physiology*; D019521:Body Patterning / Q000235:genetics*; D002450:Cell Communication / Q000235:genetics*; D002455:Cell Division / Q000235:genetics; D019070:Cell Lineage / Q000235:genetics; D047108:Embryonic Development / Q000235:genetics / Q000502:physiology; D005964:Glucosyltransferases / Q000235:genetics* / Q000502:physiology*; D020125:Mutation, Missense / Q000502:physiology*; D054046:Plant Stomata / Q000196:embryology*; D030821:Plants, Genetically Modified; D012639:Seeds
chemical_list: D029681:Arabidopsis Proteins; D005964:Glucosyltransferases; C549616:chorus protein, Arabidopsis; C020570:1,3-beta-glucan synthase