Transcriptional regulation by an NAC (NAM-ATAF1,2-CUC2) transcription factor attenuates ABA signalling for efficient basal defence towards Blumeria graminis f. sp. hordei in Arabidopsis

Plant J. 2008 Dec;56(6):867-80. doi: 10.1111/j.1365-313X.2008.03646.x. Epub 2008 Oct 4.


ATAF1 is a member of a largely uncharacterized plant-specific gene family encoding NAC transcription factors, and is induced in response to various abiotic and biotic stimuli in Arabidopsis thaliana. Previously, we showed that a mutant allele of ATAF1 compromises penetration resistance in Arabidopsis with respect to the non-host biotrophic pathogen Blumeria graminis f. sp. hordei (Bgh). In this study, we have used genome-wide transcript profiling to characterize signalling perturbations in ataf1 plants following Bgh inoculation. Comparative transcriptomic analyses identified an over-representation of abscisic acid (ABA)-responsive genes, including the ABA biosynthesis gene AAO3, which is significantly induced in ataf1 plants compared to wild-type plants following inoculation with Bgh. Additionally, we show that Bgh inoculation results in decreased endogenous ABA levels in an ATAF1-dependent manner, and that the ABA biosynthetic mutant aao3 showed increased penetration resistance to Bgh compared to wild-type plants. Furthermore, we show that ataf1 plants show ABA-hyposensitive phenotypes during seedling development and germination. Our data support a negative correlation between ABA levels and penetration resistance, and identify ATAF1 as a new stimuli-dependent attenuator of ABA signalling for the mediation of efficient penetration resistance in Arabidopsis upon Bgh attack.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abscisic Acid / metabolism*
  • Aldehyde Oxidase / genetics
  • Aldehyde Oxidase / metabolism
  • Arabidopsis / genetics*
  • Arabidopsis / metabolism
  • Arabidopsis / microbiology
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Ascomycota / pathogenicity*
  • Cluster Analysis
  • Gene Expression Profiling
  • Gene Expression Regulation, Plant
  • Mutation
  • Oligonucleotide Array Sequence Analysis
  • Phenotype
  • Plant Stomata / metabolism
  • RNA, Plant / metabolism
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*


  • ATAF1 protein, Arabidopsis
  • Arabidopsis Proteins
  • RNA, Plant
  • Repressor Proteins
  • Transcription Factors
  • Abscisic Acid
  • AAO3 protein, Arabidopsis
  • Aldehyde Oxidase