title: Roles of the middle domain-specific WUSCHEL-RELATED HOMEOBOX genes in early development of leaves in Arabidopsis.
abstract: During leaf development in flowering plants, adaxial (upper) and abaxial (lower) side-specific genes are responsible for blade outgrowth, which takes places predominantly in the lateral direction, and for margin development as well as differentiation of adaxial and abaxial tissues. However, the underlying mechanisms are poorly understood. Here, we show that two WUSCHEL-RELATED HOMEOBOX (WOX) genes, PRESSED FLOWER (PRS)/WOX3 and WOX1, encoding homeobox transcription factors, act in blade outgrowth and margin development downstream of adaxial/abaxial polarity establishment. The expression of PRS and WOX1 defines a hitherto undescribed middle domain, including two middle mesophyll layers and the margin, as a center that organizes the outgrowth of leaf blades. The expression of PRS and WOX1 is repressed in the abaxial leaf domain by the abaxial-specific transcription factor KANADI. Furthermore, PRS and WOX1 coordinate adaxial/abaxial patterning together with adaxial- and abaxial-specific genes. Our data suggest a model of blade outgrowth and adaxial/abaxial patterning via the middle domain-specific WOX genes in Arabidopsis thaliana leaves.
authors.affiliation: National Institute for Basic Biology, Myodaiji-cho, Okazaki Aichi 444-8585, Japan.
authors.forename: Miyuki
authors.initials: M
authors.lastname: Nakata
authors.forename: Noritaka
authors.initials: N
authors.lastname: Matsumoto
authors.forename: Ryuji
authors.initials: R
authors.lastname: Tsugeki
authors.forename: Enno
authors.initials: E
authors.lastname: Rikirsch
authors.forename: Thomas
authors.initials: T
authors.lastname: Laux
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Okada
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D005801:Genes, Homeobox; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D016254:Mutagenesis, Insertional; D018515:Plant Leaves / Q000166:cytology / Q000254:growth & development*
chemical_list: D029681:Arabidopsis Proteins; D018398:Homeodomain Proteins; C568610:WOX1 protein, Arabidopsis