A biochemical framework for RNA silencing in plants

UMMS Affiliation

Department of Biochemistry and Molecular Pharmacology

Publication Date


Document Type



Arabidopsis; Arabidopsis Proteins; Endoribonucleases; *Gene Expression Regulation, Plant; Genes, Dominant; Homeodomain Proteins; MicroRNAs; Plant Extracts; Plant Proteins; *RNA Interference; RNA Replicase; RNA, Double-Stranded; RNA, Plant; RNA, Small Interfering; Ribonuclease III; Triticum


Life Sciences | Medicine and Health Sciences


RNA silencing phenomena were first discovered in plants, yet only the RNA interference pathway in animals has been subject to biochemical analysis. Here, we extend biochemical analysis to plant RNA silencing. We find that standard wheat germ extract contains Dicer-like enzymes that convert double-stranded RNA (dsRNA) into two classes of small interfering RNAs, as well as an RNA-dependent RNA polymerase activity that can convert exogenous single-stranded RNA into dsRNA. In this plant embryo extract, an endogenous microRNA (miRNA) that lacks perfect complementarity to its RNA targets nonetheless acts as a small interfering RNA. The miRNA guides an endonuclease to cleave efficiently wild-type Arabidopsis PHAVOLUTA mRNA, but not a dominant mutant previously shown to perturb leaf development. This finding supports the view that plant miRNAs direct RNAi and that miRNA-specified mRNA destruction is important for proper plant development. Thus, endonuclease complexes guided by small RNAs are a common feature of RNA silencing in both animals and plants.

DOI of Published Version



Genes Dev. 2003 Jan 1;17(1):49-63. Link to article on publisher's site

Journal/Book/Conference Title

Genes and development

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Link to Article in PubMed

PubMed ID