title: Highly specific gene silencing by artificial miRNAs in rice.
abstract: BACKGROUND
  Endogenous microRNAs (miRNAs) are potent negative regulators of gene expression in plants and animals. Artificial miRNAs (amiRNAs)-designed to target one or several genes of interest-provide a new and highly specific approach for effective post-transcriptional gene silencing (PTGS) in plants.
  
  
  METHODS
  We devised an amiRNA-based strategy for both japonica and indica type strains of cultivated rice, Oryza sativa. Using an endogenous rice miRNA precursor and customized 21mers, we designed amiRNA constructs targeting three different genes (Pds, Spl11, and Eui1/CYP714D1). Upon constitutive expression of these amiRNAs in the varieties Nipponbare (japonica) and IR64 (indica), the targeted genes are down-regulated by amiRNA-guided cleavage of the transcripts, resulting in the expected mutant phenotypes. The effects are highly specific to the target gene, the transgenes are stably inherited and they remain effective in the progeny.
  
  
  CONCLUSIONS
  Our results not only show that amiRNAs can efficiently trigger gene silencing in a monocot crop, but also that amiRNAs can effectively modulate agronomically important traits in varieties used in modern breeding programs. We provide all software tools and a protocol for the design of rice amiRNA constructs, which can be easily adapted to other crops. The approach is suited for candidate gene validation, comparative functional genomics between different varieties, and for improvement of agronomic performance and nutritional value.
authors: Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany. norman@warthmann.com
authors: Norman
authors: N
authors: Warthmann
authors: Hao
authors: H
authors: Chen
authors: Stephan
authors: S
authors: Ossowski
authors: Detlef
authors: D
authors: Weigel
authors: Philippe
authors: P
authors: Hervé
mesh_terms: D020868:Gene Silencing; D017343:Genes, Plant; D035683:MicroRNAs / Q000737:chemistry / Q000502:physiology*; D009690:Nucleic Acid Conformation; D012275:Oryza / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D035683:MicroRNAs