title: A variant of LEAFY reveals its capacity to stimulate meristem development by inducing RAX1.
abstract: In indeterminate inflorescences, floral meristems develop on the flanks of the shoot apical meristem, at positions determined by auxin maxima. The floral identity of these meristems is conferred by a handful of genes called floral meristem identity genes, among which the LEAFY (LFY) transcription factor plays a prominent role. However, the molecular mechanism controlling the early emergence of floral meristems remains unknown. A body of evidence indicates that LFY may contribute to this developmental shift, but a direct effect of LFY on meristem emergence has not been demonstrated. We have generated a LFY allele with reduced floral function and revealed its ability to stimulate axillary meristem growth. This role is barely detectable in the lfy single mutant but becomes obvious in several double mutant backgrounds and plants ectopically expressing LFY. We show that this role requires the ability of LFY to bind DNA, and is mediated by direct induction of REGULATOR OF AXILLARY MERISTEMS1 (RAX1) by LFY. We propose that this function unifies the diverse roles described for LFY in multiple angiosperm species, ranging from monocot inflorescence identity to legume leaf development, and that it probably pre-dates the origin of angiosperms.
authors: Laboratoire Physiologie Cellulaire et Végétale, CEA (Commissariat à l'Energie Atomique et aux Energies Alternatives), iRTSV (Institut de Recherches en Technologies et Sciences pour le Vivant), Grenoble, F-38054, France.
authors: Hicham
authors: H
authors: Chahtane
authors: Gilles
authors: G
authors: Vachon
authors: Marie
authors: M
authors: Le Masson
authors: Emmanuel
authors: E
authors: Thévenon
authors: Sophie
authors: S
authors: Périgon
authors: Nela
authors: N
authors: Mihajlovic
authors: Anna
authors: A
authors: Kalinina
authors: Robin
authors: R
authors: Michard
authors: Edwige
authors: E
authors: Moyroud
authors: Marie
authors: M
authors: Monniaux
authors: Camille
authors: C
authors: Sayou
authors: Vojislava
authors: V
authors: Grbic
authors: Francois
authors: F
authors: Parcy
authors: Gabrielle
authors: G
authors: Tichtinsky
mesh_terms: D000483:Alleles; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D003461:Crystallography; D004268:DNA-Binding Proteins; D035264:Flowers / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D018519:Meristem / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D008954:Models, Biological; D009154:Mutation; D059372:Nucleotide Motifs; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D030821:Plants, Genetically Modified; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary; D036226:Seedlings / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D020798:Two-Hybrid System Techniques
chemical_list: D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; C074747:LFY protein, Arabidopsis; C510420:RAX1 protein, Arabidopsis; D014157:Transcription Factors