title: WOX4 and WOX14 act downstream of the PXY receptor kinase to regulate plant vascular proliferation independently of any role in vascular organisation.
abstract: In plants, the cambium and procambium are meristems from which vascular tissue is derived. In contrast to most plant cells, stem cells within these tissues are thin and extremely long. They are particularly unusual as they divide down their long axis in a highly ordered manner, parallel to the tangential axis of the stem. CLAVATA3-LIKE/ESR-RELATED 41 (CLE41) and PHLOEM INTERCALATED WITH XYLEM (PXY) are a multifunctional ligand-receptor pair that regulate vascular cell division, vascular organisation and xylem differentiation in vascular tissue. A transcription factor gene, WUSCHEL HOMEOBOX RELATED 4 (WOX4) has been shown to act downstream of PXY. Here we show that WOX4 acts redundantly with WOX14 in the regulation of vascular cell division, but that these genes have no function in regulating vascular organisation. Furthermore, we identify an interaction between PXY and the receptor kinase ERECTA (ER) that affects the organisation of the vascular tissue but not the rate of cell division, suggesting that cell division and vascular organisation are genetically separable. Our observations also support a model whereby tissue organisation and cell division are integrated via PXY and ER signalling, which together coordinate development of different cell types that are essential for normal stem formation.
authors.affiliation: University of Manchester, Faculty of Life Sciences, Manchester M13 9PT, UK.
authors.forename: J Peter
authors.initials: JP
authors.lastname: Etchells
authors.forename: Claire M
authors.initials: CM
authors.lastname: Provost
authors.forename: Laxmi
authors.initials: L
authors.lastname: Mishra
authors.forename: Simon R
authors.initials: SR
authors.lastname: Turner
mesh_terms: D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D058506:Cambium / Q000502:physiology*; D002455:Cell Division; D002462:Cell Membrane / Q000378:metabolism; D003433:Crosses, Genetic; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology*; D008024:Ligands; D009154:Mutation; D010641:Phenotype; D052585:Phloem / Q000378:metabolism; D011494:Protein Kinases / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism / Q000502:physiology*; D011956:Receptors, Cell Surface / Q000378:metabolism / Q000502:physiology*; D015398:Signal Transduction; D052584:Xylem / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D018398:Homeodomain Proteins; D008024:Ligands; D011956:Receptors, Cell Surface; C581876:WOX14 protein, Arabidopsis; C581875:WOX4 protein, Arabidopsis; D011494:Protein Kinases; C457763:ER protein, Arabidopsis; C524131:PXY protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases