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Published online: 24 October 2007 | doi:10.1038/nchina.2007.224

siRNA silencing: Rice dicer

Wei Zeng

Introduction

© (2007) American Society of Plant Biologists

Dicer or dicer-like (DCL) proteins can recognize specific sequences on RNAs for cleavage, which they snip to form shorter strands with 21–24 nucleotides, known as small interfering RNAs (siRNAs). Plants are known to use siRNAs to silence gene expression during development. Xiaofeng Cao at the Chinese Academy of Sciences in Beijing and co-workers¹ have investigated how rice uses Oryza sativa (Os) DCL-4 protein to regulate siRNAs for silencing.

Scientists have known about the specialized functions of each of the four DCL proteins in the plant Arabidopsis thaliana. However, the six DCL proteins in rice, including DCL-4, are not well understood.

Using biochemical and genetic analysis, the researchers demonstrated that Os DCL-4 is a major dicer responsible for generating the 21-nucleotide siRNAs from two RNA families — inverted repeat transgenes and TAS3. They found that rice lacking Os DCL-4 has vegetative growth abnormalities and severe developmental defects (see image). Os DCL-4 can also cleave RNAs, which are used to create microRNAs (another class of small regulatory RNAs), suggesting an evolutionary link between siRNAs and microRNAs.

The authors of this work are from:
State Key Laboratory of Plant Genomics, Laboratory of Molecular and Developmental Biology and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China; Graduate University of the Chinese Academy of Sciences, Beijing, China; National Institute of Biological Science, Beijing, China; Department of Molecular, Cellular, and Development Biology, Yale University, New Haven, Connecticut, USA.

Reference

1. Liu, B.et al. Oryza sativa dicer-like4 reveals a key role for small interfering RNA silencing in plant development. Plant Cell doi: 10.1105/tpc.107.052209 (2007). | Article |