Interplay among RNA polymerases II, IV and V in RNA-directed DNA methylation at a low copy transgene locus in Arabidopsis thaliana

Interplay among RNA polymerases II, IV and V in RNA-directed DNA methylation at a low copy... RNA-directed DNA methylation (RdDM) is an epigenetic process whereby small interfering RNAs (siRNAs) guide cytosine methylation of homologous DNA sequences. RdDM requires two specialized RNA polymerases: Pol IV transcribes the siRNA precursor whereas Pol V generates scaffold RNAs that interact with siRNAs and attract the methylation machinery. Recent evidence also suggests the involvement of RNA polymerase II (Pol II) in recruiting Pol IV and Pol V to low copy, intergenic loci. We demonstrated previously that Pol V-mediated methylation at a transgene locus in Arabidopsis spreads downstream of the originally targeted region by means of Pol IV/RNA-DEPENDENT RNA POLYMERASE2 (RDR2)-dependent 24-nt secondary siRNAs. Here we show that these secondary siRNAs can not only induce methylation in cis but also in trans at an unlinked target site, provided this sequence is transcribed by Pol II to produce a non-coding RNA. The Pol II transcript appears to be important for amplification of siRNAs at the unlinked target site because its presence correlates not only with methylation but also with elevated levels of 24-nt siRNAs. Potential target sites that lack an overlapping Pol II transcript and remain unmethylated in the presence of trans-acting 24-nt siRNAs can nevertheless acquire methylation in the presence of 21–24-nt hairpin-derived siRNAs, suggesting that RdDM of non-transcribed target sequences requires multiple size classes of siRNA. Our findings demonstrate that Pol II transcripts are not always needed for RdDM at low copy loci but they may intensify RdDM by facilitating amplification of Pol IV-dependent siRNAs at the DNA target site. Plant Molecular Biology Springer Journals

Interplay among RNA polymerases II, IV and V in RNA-directed DNA methylation at a low copy transgene locus in Arabidopsis thaliana

Loading next page...
Springer Netherlands
Copyright © 2013 by The Author(s)
Life Sciences; Plant Sciences; Biochemistry, general; Plant Pathology
Publisher site
See Article on Publisher Site


You’re reading a free preview. Subscribe to read the entire article.

DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

Monthly Plan

  • Read unlimited articles
  • Personalized recommendations
  • No expiration
  • Print 20 pages per month
  • 20% off on PDF purchases
  • Organize your research
  • Get updates on your journals and topic searches


Start Free Trial

14-day Free Trial

Best Deal — 39% off

Annual Plan

  • All the features of the Professional Plan, but for 39% off!
  • Billed annually
  • No expiration
  • For the normal price of 10 articles elsewhere, you get one full year of unlimited access to articles.



billed annually
Start Free Trial

14-day Free Trial