a collection of target mimics for comprehensive analysis of microrna function in arabidopsis thaliana一组目标模拟综合分析拟南芥的微rna的功能.pdfVIP

A Collection of Target Mimics for Comprehensive Analysis of MicroRNA Function in Arabidopsis thaliana 1. 1. 2 1 Marco Todesco , Ignacio Rubio-Somoza , Javier Paz-Ares , Detlef Weigel * ¨ 1 Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tubingen, Germany, 2 Department of Plant Molecular Genetics, Centro Nacional de ´ ´ Biotecnologıa–Consejo Superior de Investigaciones Cientıficas, Madrid, Spain Abstract Many targets of plant microRNAs (miRNAs) are thought to play important roles in plant physiology and development. However, because plant miRNAs are typically encoded by medium-size gene families, it has often been difficult to assess their precise function. We report the generation of a large-scale collection of knockdowns for Arabidopsis thaliana miRNA families; this has been achieved using artificial miRNA target mimics, a recently developed technique fashioned on an endogenous mechanism of miRNA regulation. Morphological defects in the aerial part were observed for ,20% of analyzed families, all of which are deeply conserved in land plants. In addition, we find that non-cleavable mimic sites can confer translational regulation in cis. Phenotypes of plants expressing target mimics directed against miRNAs involved in development were in several cases consistent with previous reports on plants expressing miRNA–resistant forms of individual target genes