RNA-directed de novo methylation of genomic sequences in plants

Cell. 1994 Feb 11;76(3):567-76. doi: 10.1016/0092-8674(94)90119-8.


One monomeric and three oligomeric potato spindle tuber viroid (PSTVd) cDNA units were introduced into the tobacco genome via the Agrobacterium-mediated leaf-disc transformation. Southern analysis of the integrates revealed that only their PSTVd-specific sequences become fully methylated, whereas the flanking T-DNA and the genomic plant DNA remain unaltered. Viroid cDNA methylation could only be observed after autonomous viroid RNA-RNA replication had taken place in these plants. These findings demonstrate that a mechanism of de novo methylation of genes might exist that can be induced and targeted in a sequence-specific manner by their own mRNA.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Blotting, Northern
  • Blotting, Southern
  • DNA / metabolism*
  • DNA, Viral / metabolism*
  • Genes, Plant*
  • Methylation
  • Molecular Sequence Data
  • Plants, Genetically Modified
  • Plants, Toxic*
  • RNA, Viral / metabolism*
  • Restriction Mapping
  • Rhizobium / genetics
  • Rhizobium / physiology*
  • Tobacco / genetics
  • Tobacco / metabolism*
  • Viroids / physiology
  • Virus Replication


  • DNA, Viral
  • RNA, Viral
  • DNA