Early genomic responses to salicylic acid in Arabidopsis

Plant Mol Biol. 2009 May;70(1-2):79-102. doi: 10.1007/s11103-009-9458-1. Epub 2009 Feb 7.

Abstract

Salicylic acid (SA) is a stress-induced hormone involved in the activation of defense genes. Here we analyzed the early genetic responses to SA of wild type and npr1-1 mutant Arabidopsis seedlings, using Complete Arabidopsis Transcriptome MicroArray (CATMAv2) chip. We identified 217 genes rapidly induced by SA (early SAIGs); 193 by a NPR1-dependent and 24 by a NPR1-independent pathway. These two groups of genes also differed in their functional classification, expression profiles and over-representation of cis-elements, supporting differential pathways for their activation. Examination of the expression patterns for selected early SAIGs from both groups indicated that their activation by SA required TGA2/5/6 subclass of transcription factors. These genes were also activated by Pseudomonas syringae pv. tomato AvrRpm1, suggesting that they might play a role in defense against bacteria. This study gives a global idea of the early response to SA in Arabidopsis seedlings, expanding our knowledge about SA function in plant defense.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / drug effects
  • Arabidopsis / genetics*
  • Arabidopsis / metabolism
  • Arabidopsis / microbiology
  • Gene Expression Profiling
  • Gene Expression Regulation, Plant
  • Genes, Plant
  • Genome, Plant*
  • Oligonucleotide Array Sequence Analysis
  • Promoter Regions, Genetic
  • Pseudomonas syringae / physiology
  • RNA, Plant / genetics
  • Salicylic Acid / pharmacology*
  • Seedlings / drug effects
  • Seedlings / genetics*
  • Seedlings / metabolism
  • Seedlings / microbiology
  • Transcription Factors / genetics
  • Transcription, Genetic
  • Transcriptional Activation

Substances

  • RNA, Plant
  • Transcription Factors
  • Salicylic Acid