title: Endogenous and synthetic microRNAs stimulate simultaneous, efficient, and localized regulation of multiple targets in diverse species.
abstract: Recent studies demonstrated that pattern formation in plants involves regulation of transcription factor families by microRNAs (miRNAs). To explore the potency, autonomy, target range, and functional conservation of miRNA genes, a systematic comparison between plants ectopically expressing pre-miRNAs and plants with corresponding multiple mutant combinations of target genes was performed. We show that regulated expression of several Arabidopsis thaliana pre-miRNA genes induced a range of phenotypic alterations, the most extreme ones being a phenocopy of combined loss of their predicted target genes. This result indicates quantitative regulation by miRNA as a potential source for diversity in developmental outcomes. Remarkably, custom-made, synthetic miRNAs vectored by endogenous pre-miRNA backbones also produced phenocopies of multiple mutant combinations of genes that are not naturally regulated by miRNA. Arabidopsis-based endogenous and synthetic pre-miRNAs were also processed effectively in tomato (Solanum lycopersicum) and tobacco (Nicotiana tabacum). Synthetic miR-ARF targeting Auxin Response Factors 2, 3, and 4 induced dramatic transformations of abaxial tissues into adaxial ones in all three species, which could not cross graft joints. Likewise, organ-specific expression of miR165b that coregulates the PHABULOSA-like adaxial identity genes induced localized abaxial transformations. Thus, miRNAs provide a flexible, quantitative, and autonomous platform that can be employed for regulated expression of multiple related genes in diverse species.
authors.affiliation: Department of Plant Sciences, Weizman Institute of Science, Rehovot, 76100, Israel.
authors.forename: John Paul
authors.initials: JP
authors.lastname: Alvarez
authors.forename: Irena
authors.initials: I
authors.lastname: Pekker
authors.forename: Alexander
authors.initials: A
authors.lastname: Goldshmidt
authors.forename: Eyal
authors.initials: E
authors.lastname: Blum
authors.forename: Ziva
authors.initials: Z
authors.lastname: Amsellem
authors.forename: Yuval
authors.initials: Y
authors.lastname: Eshed
mesh_terms: D017360:Arabidopsis / Q000033:anatomy & histology / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D015536:Down-Regulation; D018506:Gene Expression Regulation, Plant; D018551:Solanum lycopersicum / Q000033:anatomy & histology / Q000235:genetics / Q000378:metabolism; D035683:MicroRNAs / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D009154:Mutation; D009690:Nucleic Acid Conformation; D010641:Phenotype; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012319:RNA Polymerase II / Q000502:physiology; D018749:RNA, Plant / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D014026:Nicotiana / Q000033:anatomy & histology / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D035683:MicroRNAs; D010940:Plant Proteins; D018749:RNA, Plant; D012319:RNA Polymerase II