title: Early genomic responses to salicylic acid in Arabidopsis.
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.
authors.affiliation: Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, P.O. Box 114-D, Santiago, Chile.
authors.forename: Francisca
authors.initials: F
authors.lastname: Blanco
authors.forename: Paula
authors.initials: P
authors.lastname: Salinas
authors.forename: Nicolás M
authors.initials: NM
authors.lastname: Cecchini
authors.forename: Xavier
authors.initials: X
authors.lastname: Jordana
authors.forename: Paul
authors.initials: P
authors.lastname: Van Hummelen
authors.forename: María Elena
authors.initials: ME
authors.lastname: Alvarez
authors.forename: Loreto
authors.initials: L
authors.lastname: Holuigue
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D018745:Genome, Plant; D020411:Oligonucleotide Array Sequence Analysis; D011401:Promoter Regions, Genetic; D044224:Pseudomonas syringae / Q000502:physiology; D018749:RNA, Plant / Q000235:genetics; D020156:Salicylic Acid / Q000494:pharmacology*; D036226:Seedlings / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D014157:Transcription Factors / Q000235:genetics; D014158:Transcription, Genetic; D015533:Transcriptional Activation
chemical_list: D018749:RNA, Plant; D014157:Transcription Factors; D020156:Salicylic Acid