MicroRNA binding sites in Arabidopsis class III HD-ZIP mRNAs are required for methylation of the template chromosome

Dev Cell. 2004 Nov;7(5):653-62. doi: 10.1016/j.devcel.2004.10.003.


Dominant mutations in the Arabidopsis PHABULOSA (PHB) and PHAVOLUTA (PHV) transcription factor genes cause transformation of abaxial to adaxial leaf fates by altering a microRNA complementary site present in processed PHB and PHV mRNAs but not in the corresponding genomic DNA. phb-1d mutants accumulate excess PHB transcript throughout the leaf primordium, indicating defective regulation of PHB transcript synthesis and/or stability. We show that PHB and PHV coding sequences are heavily methylated downstream of the microRNA complementary site in most wild-type plant cells and that methylation is reduced in phb-1d and phv-1d mutants. Decreased methylation is limited to the chromosome bearing the dominant mutant allele in phb-1d heterozygotes. Low levels of methylation are detected in wt PHB DNA isolated from undifferentiated tissues. These results suggest a model in which the microRNA interacts with nascent, newly processed PHB mRNA to alter chromatin of the corresponding PHB template DNA predominantly in differentiated cells.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alleles
  • Arabidopsis / genetics
  • Arabidopsis / growth & development
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / chemistry
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Base Sequence
  • Binding Sites
  • Chromosome Mapping
  • Chromosomes, Plant*
  • CpG Islands
  • DNA Methylation*
  • DNA, Plant / drug effects
  • Exons
  • Genes, Dominant
  • Genes, Plant
  • Heterozygote
  • MicroRNAs / chemistry
  • MicroRNAs / metabolism*
  • Models, Biological
  • Molecular Sequence Data
  • Mutation
  • RNA, Messenger / classification
  • RNA, Messenger / metabolism*
  • RNA, Plant / chemistry
  • RNA, Plant / isolation & purification
  • RNA, Plant / metabolism
  • Sequence Homology, Nucleic Acid
  • Sulfites / toxicity
  • Templates, Genetic
  • Transcription Factors / genetics


  • Arabidopsis Proteins
  • DNA, Plant
  • MicroRNAs
  • RNA, Messenger
  • RNA, Plant
  • Sulfites
  • Transcription Factors