title: Convergent repression of miR156 by sugar and the CDK8 module of Arabidopsis Mediator.
abstract: In Arabidopsis, leaves produced during the juvenile vegetative phase are simple, while adult leaves are morphologically complex. The juvenile to adult transition is regulated by miR156, a microRNA that promotes juvenility by impeding the function of SPL transcription factors, which specify adult leaf traits. Both leaf derived sugars, as well as the Mediator Cyclin Dependent Kinase 8 (CDK8) module genes CENTER CITY (CCT)/MED12 and GRAND CENTRAL (GCT)/MED13, act upstream of miR156 to promote the juvenile to adult transition. However, it is not known whether sugar, CCT and GCT repress miR156 independently, as part of the same pathway, or in a cooperative manner. Here we show that sugar treatment can repress MIR156 expression in the absence of CCT or GCT. Both cct and the photosynthetic mutant chlorina1 (ch1) (which decreases sugar synthesis) exhibit extended juvenile development and increased MIR156A and MIR156C expression. Compared to ch1 and cct single mutants, the ch1 cct double mutant has a stronger effect on juvenile leaf traits, higher MIR156C levels, and a dramatic increase in MIR156A. Our results show that sugar and the CDK8 module are capable of regulating MIR156 independently, but suggest they normally act together in a synergistic manner.
authors.affiliation: Laboratorio Nacional de Genómica para la Biodiversidad (Langebio), Unidad de Genómica Avanzada, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV), Irapuato, Guanajuato, Mexico.
authors.forename: Manuel
authors.initials: M
authors.lastname: Buendía-Monreal
authors.affiliation: Laboratorio Nacional de Genómica para la Biodiversidad (Langebio), Unidad de Genómica Avanzada, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV), Irapuato, Guanajuato, Mexico. Electronic address: stewart.gillmor@cinvestav.mx.
authors.forename: C Stewart
authors.initials: CS
authors.lastname: Gillmor
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002241:Carbohydrates / Q000494:pharmacology*; D056850:Cyclin-Dependent Kinase 8 / Q000378:metabolism*; D035264:Flowers / Q000187:drug effects / Q000502:physiology; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D056892:Mediator Complex / Q000378:metabolism*; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D019655:Quantitative Trait, Heritable; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism*; D012098:Reproduction / Q000187:drug effects
chemical_list: D029681:Arabidopsis Proteins; D002241:Carbohydrates; D056850:Cyclin-Dependent Kinase 8; D056892:Mediator Complex; D035683:MicroRNAs; D012333:RNA, Messenger; D012097:Repressor Proteins; C559759:Mirn156 microRNA, Arabidopsis; C522174:AT5G63610 protein, Arabidopsis
keywords: MED12; MED13; Mediator; Sugar; Vegetative phase change; miR156