title: The microRNA regulated SBP-box genes SPL9 and SPL15 control shoot maturation in Arabidopsis.
abstract: Throughout development the Arabidopsis shoot apical meristem successively undergoes several major phase transitions such as the juvenile-to-adult and floral transitions until, finally, it will produce flowers instead of leaves and shoots. Members of the Arabidopsis SBP-box gene family of transcription factors have been implicated in promoting the floral transition in dependence of miR156 and, accordingly, transgenics constitutively over-expressing this microRNA are delayed in flowering. To elaborate their roles in Arabidopsis shoot development, we analysed two of the 11 miR156 regulated Arabidopsis SBP-box genes, i.e. the likely paralogous genes SPL9 and SPL15. Single and double mutant phenotype analysis showed these genes to act redundantly in controlling the juvenile-to-adult phase transition. In addition, their loss-of-function results in a shortened plastochron during vegetative growth, altered inflorescence architecture and enhanced branching. In these aspects, the double mutant partly phenocopies constitutive MIR156b over-expressing transgenic plants and thus a major contribution to the phenotype of these transgenics as a result of the repression of SPL9 and SPL15 is strongly suggested.
authors.affiliation: Max-Planck-Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, Cologne, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Schwarz
authors.forename: Arne V
authors.initials: AV
authors.lastname: Grande
authors.forename: Nora
authors.initials: N
authors.lastname: Bujdoso
authors.forename: Heinz
authors.initials: H
authors.lastname: Saedler
authors.forename: Peter
authors.initials: P
authors.lastname: Huijser
mesh_terms: D000483:Alleles; D020816:Amino Acid Motifs; D017360:Arabidopsis / Q000033:anatomy & histology / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D005875:Gibberellins / Q000494:pharmacology / Q000502:physiology; D035683:MicroRNAs / Q000502:physiology*; D010641:Phenotype; D010802:Phylogeny; D010937:Plant Growth Regulators / Q000494:pharmacology / Q000502:physiology; D018515:Plant Leaves / Q000033:anatomy & histology / Q000235:genetics / Q000254:growth & development; D018520:Plant Shoots / Q000033:anatomy & histology / Q000235:genetics / Q000254:growth & development; D015534:Trans-Activators; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
chemical_list: D029681:Arabidopsis Proteins; D005875:Gibberellins; D035683:MicroRNAs; D010937:Plant Growth Regulators; C531405:SPL15 protein, Arabidopsis; C531404:SPL9 protein, Arabidopsis; D015534:Trans-Activators; D014157:Transcription Factors