An mRNA cap binding protein, ABH1, modulates early abscisic acid signal transduction in Arabidopsis

Cell. 2001 Aug 24;106(4):477-87. doi: 10.1016/s0092-8674(01)00460-3.


The plant hormone abscisic acid (ABA) regulates important stress and developmental responses. We have isolated a recessive ABA hypersensitive mutant, abh1, that shows hormone specificity to ABA. ABH1 encodes the Arabidopsis homolog of a nuclear mRNA cap binding protein and functions in a heterodimeric complex to bind the mRNA cap structure. DNA chip analyses show that only a few transcripts are down-regulated in abh1, several of which are implicated in ABA signaling. Consistent with these results, abh1 plants show ABA-hypersensitive stomatal closing and reduced wilting during drought. Interestingly, ABA-hypersensitive cytosolic calcium increases in abh1 guard cells demonstrate amplification of early ABA signaling. Thus, ABH1 represents a modulator of ABA signaling proposed to function by transcript alteration of early ABA signaling elements.

Publication types

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

MeSH terms

  • Abscisic Acid / pharmacology*
  • Arabidopsis / cytology
  • Arabidopsis / genetics*
  • Arabidopsis / physiology*
  • Arabidopsis Proteins*
  • Blotting, Northern
  • Calcium / metabolism
  • Epistasis, Genetic
  • Genes, Reporter
  • Humans
  • Molecular Sequence Data
  • Oligonucleotide Array Sequence Analysis
  • Plant Growth Regulators / pharmacology
  • RNA Cap-Binding Proteins
  • RNA Caps / metabolism
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism*
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Seeds / physiology
  • Signal Transduction / physiology*
  • Two-Hybrid System Techniques


  • ABH1 protein, Arabidopsis
  • Arabidopsis Proteins
  • Plant Growth Regulators
  • RNA Cap-Binding Proteins
  • RNA Caps
  • RNA-Binding Proteins
  • Recombinant Fusion Proteins
  • Abscisic Acid
  • Calcium

Associated data

  • GENBANK/AF272891