Journal Article

Regulation of MIR165/166 by class II and class III homeodomain leucine zipper proteins establishes leaf polarity

Heisler, Marcus G., Ott, Felix, Cho, Seok Keun, Yang, Seong Wook, Ohno, Carolyn, Wenkel, Stephan, Ram, Hathi, Merelo, Paz, Straub, Daniel, Graeff, Moritz, Caggiano, Monica Pia

2016

Overview

A defining feature of plant leaves is their flattened shape. This shape depends on an antagonism between the genes that specify adaxial (top) and abaxial (bottom) tissue identity; however, the molecular nature of this antagonism remains poorly understood. Class III homeodomain leucine zipper (HD-ZIP) transcription factors are key mediators in the regulation of adaxial–abaxial patterning. Their expression is restricted adaxially during early development by the abaxially expressed microRNA (MIR)165/166, yet the mechanism that restricts MIR165/166 expression to abaxial leaf tissues remains unknown. Here, we show that class III and class II HD-ZIP proteins act together to repress MIR165/166 via a conserved cis-element in their promoters. Organ morphology and tissue patterning in plants, therefore, depend on a bidirectional repressive circuit involving a set of miRNAs and its targets.

• Publisher: National Academy of Sciences
• Subject: Amino acids / Arabidopsis - genetics / Arabidopsis - metabolism / Arabidopsis Proteins - genetics / Biological Sciences / Biomarkers / Conserved Sequence / Flowers & plants / Gene expression / Gene Expression Regulation, Plant / Genes / Homeodomain Proteins - chemistry / Homeodomain Proteins - genetics / Homeodomain Proteins - metabolism / Leaves / Leucine Zippers - genetics / MicroRNAs - genetics / Models, Biological / Plant Biology / Plant Development - genetics / Plant Leaves - genetics / Plant tissues / Plants / Protein Binding / Quantitative Trait, Heritable / Response Elements / Ribonucleic acid / RNA