The expanding world of small RNAs in plants

Nat Rev Mol Cell Biol. 2015 Dec;16(12):727-41. doi: 10.1038/nrm4085. Epub 2015 Nov 4.


Plant genomes encode various small RNAs that function in distinct, yet overlapping, genetic and epigenetic silencing pathways. However, the abundance and diversity of small-RNA classes varies among plant species, suggesting coevolution between environmental adaptations and gene-silencing mechanisms. Biogenesis of small RNAs in plants is well understood, but we are just beginning to uncover their intricate regulation and activity. Here, we discuss the biogenesis of plant small RNAs, such as microRNAs, secondary siRNAs and heterochromatic siRNAs, and their diverse cellular and developmental functions, including in reproductive transitions, genomic imprinting and paramutation. We also discuss the diversification of small-RNA-directed silencing pathways through the expansion of RNA-dependent RNA polymerases, DICER proteins and ARGONAUTE proteins.

Publication types

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

MeSH terms

  • Arabidopsis / genetics
  • Arabidopsis / metabolism*
  • Argonaute Proteins / metabolism
  • Gene Expression Regulation, Plant
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • RNA Interference
  • RNA Replicase / metabolism
  • RNA Splicing / genetics
  • RNA, Plant / genetics
  • RNA, Plant / metabolism*
  • RNA, Small Cytoplasmic / genetics
  • RNA, Small Cytoplasmic / metabolism*
  • RNA, Small Interfering / genetics
  • RNA, Small Interfering / metabolism*
  • Ribonuclease III / metabolism


  • Argonaute Proteins
  • MicroRNAs
  • RNA, Plant
  • RNA, Small Cytoplasmic
  • RNA, Small Interfering
  • RNA Replicase
  • Ribonuclease III