title: Temporal control of leaf complexity by miRNA-regulated licensing of protein complexes.
abstract: The tremendous diversity of leaf shapes has caught the attention of naturalists for centuries. In addition to interspecific and intraspecific differences, leaf morphologies may differ in single plants according to age, a phenomenon known as heteroblasty. In Arabidopsis thaliana, the progression from the juvenile to the adult phase is characterized by increased leaf serration. A similar trend is seen in species with more complex leaves, such as the A. thaliana relative Cardamine hirsuta, in which the number of leaflets per leaf increases with age. Although the genetic changes that led to the overall simpler leaf architecture in A. thaliana are increasingly well understood, less is known about the events underlying age-dependent changes within single plants, in either A. thaliana or C. hirsuta. Here, we describe a conserved miRNA transcription factor regulon responsible for an age-dependent increase in leaf complexity. In early leaves, miR319-targeted TCP transcription factors interfere with the function of miR164-dependent and miR164-independent CUC proteins, preventing the formation of serrations in A. thaliana and of leaflets in C. hirsuta. As plants age, accumulation of miR156-regulated SPLs acts as a timing cue that destabilizes TCP-CUC interactions. The destabilization licenses activation of CUC protein complexes and thereby the gradual increase of leaf complexity in the newly formed organs. These findings point to posttranslational interaction between unrelated miRNA-targeted transcription factors as a core feature of these regulatory circuits.
authors.affiliation: Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Rubio-Somoza
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200032 Shanghai, China.
authors.forename: Chuan-Miao
authors.initials: CM
authors.lastname: Zhou
authors.affiliation: Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Confraria
authors.affiliation: Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal.
authors.forename: Claudia
authors.initials: C
authors.lastname: Martinho
authors.affiliation: Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany.
authors.forename: Patrick
authors.initials: P
authors.lastname: von Born
authors.affiliation: Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal.
authors.forename: Elena
authors.initials: E
authors.lastname: Baena-Gonzalez
authors.affiliation: Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany; National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 200032 Shanghai, China. Electronic address: jwwang@sibs.ac.cn.
authors.forename: Jia-Wei
authors.initials: JW
authors.lastname: Wang
authors.affiliation: Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany. Electronic address: weigel@weigelworld.org.
authors.forename: Detlef
authors.initials: D
authors.lastname: Weigel
mesh_terms: D017360:Arabidopsis / Q000033:anatomy & histology / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D035683:MicroRNAs / Q000378:metabolism; D063245:Plant Development / Q000235:genetics; D018515:Plant Leaves / Q000033:anatomy & histology / Q000254:growth & development / Q000378:metabolism; D013045:Species Specificity; D013997:Time Factors
chemical_list: D029681:Arabidopsis Proteins; D035683:MicroRNAs