title: Combined SHOOT MERISTEMLESS and WUSCHEL trigger ectopic organogenesis in Arabidopsis.
abstract: Almost all aerial parts of plants are continuously generated at the shoot apical meristem (SAM). To maintain a steady pool of undifferentiated cells in the SAM while continuously generating new organs, it is necessary to balance the rate of cell division with the rate of entrance into differentiation pathways. In the Arabidopsis meristem, SHOOT MERISTEMLESS (STM) and WUSCHEL (WUS) are necessary to keep cells undifferentiated and dividing. Here, we tested whether ectopic STM and WUS functions are sufficient to revert differentiation and activate cell division in differentiating tissues. Ectopic STM and WUS functions interacted non-additively and activated a subset of meristem functions, including cell division, CLAVATA1 expression and organogenesis, but not correct phyllotaxy or meristem self-maintenance. Our results suggest that WUS produces a non-cell autonomous signal that activates cell division in combination with STM and that combined WUS/STM functions can initiate the progression from stem cells to organ initiation.
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, UK.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Gallois
authors.forename: Claire
authors.initials: C
authors.lastname: Woodward
authors.forename: G Venugopala
authors.initials: GV
authors.lastname: Reddy
authors.forename: Robert
authors.initials: R
authors.lastname: Sablowski
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics*; D029681:Arabidopsis Proteins; D001483:Base Sequence; D002454:Cell Differentiation / Q000235:genetics; D002455:Cell Division / Q000235:genetics; D003907:Dexamethasone / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D018398:Homeodomain Proteins / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D018519:Meristem / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D011965:Receptors, Glucocorticoid / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D018398:Homeodomain Proteins; D010940:Plant Proteins; D011965:Receptors, Glucocorticoid; D011994:Recombinant Proteins; C097496:STM protein, Arabidopsis; C116421:WUSCHEL protein, Arabidopsis; D003907:Dexamethasone