Small RNA metabolism in Arabidopsis

Trends Plant Sci. 2008 Jul;13(7):368-74. doi: 10.1016/j.tplants.2008.03.008. Epub 2008 May 22.


The Arabidopsis genome encodes two major classes of 20-24-nucleotide riboregulators: microRNAs and small interfering RNAs. These small RNAs act as sequence-specific repressors of target gene expression, either at the transcriptional level through DNA and/or histone methylation or at the post-transcriptional level through transcript cleavage or translational inhibition. Small RNAs are processed from precursor RNAs by one or more of the four DICER-LIKE RNase III enzymes, modified by HUA ENHANCER 1, a small RNA methyltransferase, and loaded onto an argonaute protein-containing RNA-induced silencing complex. Here, we review the biogenesis of small RNAs, and we discuss the major outstanding questions in small RNA metabolism and function.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Review

MeSH terms

  • Arabidopsis / genetics*
  • Arabidopsis / metabolism
  • Arabidopsis / physiology
  • MicroRNAs / genetics*
  • MicroRNAs / metabolism
  • Models, Biological
  • RNA, Plant / genetics*
  • RNA, Plant / metabolism
  • RNA, Small Interfering / genetics
  • Signal Transduction / genetics
  • Signal Transduction / physiology


  • MicroRNAs
  • RNA, Plant
  • RNA, Small Interfering