title: Identification of NPR1-dependent and independent genes early induced by salicylic acid treatment in Arabidopsis.
abstract: Salicylic acid (SA) plays a crucial role in stress resistance in plants by modifying the expression of a battery of genes. In this paper, we report the identification of a group of early SA-regulated genes of Arabidopsis (activated between 0.5-2.5 h), using the cDNA-amplified fragment length polymorphism technique (cDNA-AFLP). Using 128 different primer combinations, we identified several genes based on their differential expression during SA treatment. Among these, we identified 12 genes up-regulated by SA whose patterns of induction were confirmed by Northern analysis. The identified genes can be grouped into two functional groups: Group 1: genes involved in cell protection (i.e. glycosyltransferases, glutathion S-transferases), and Group 2: genes involved in signal transduction (protein kinases and transcription factors). We also evaluated NPR1 requirement for the induction of the 12 up-regulated genes, and found that only those belonging to Group 2 require this co-activator for their expression. In silico analysis of the promoter sequences of the up-regulated genes, allowed us to identify putative cis-elements over-represented in these genes. Interestingly, as-1-like elements, previously characterized as SA-responsive elements, were specifically over-represented in Group 1 genes. The identification of early SA-regulated genes is an important step towards understanding the complex role of this hormone in plant stress resistance.
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: Virginia
authors.initials: V
authors.lastname: Garretón
authors.forename: Nicolas
authors.initials: N
authors.lastname: Frey
authors.forename: Calixto
authors.initials: C
authors.lastname: Dominguez
authors.forename: Tomás
authors.initials: T
authors.lastname: Pérez-Acle
authors.forename: Dominique
authors.initials: D
authors.lastname: Van der Straeten
authors.forename: Xavier
authors.initials: X
authors.lastname: Jordana
authors.forename: Loreto
authors.initials: L
authors.lastname: Holuigue
mesh_terms: D020816:Amino Acid Motifs; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism*; D015152:Blotting, Northern; D003517:Cyclopentanes / Q000378:metabolism; D017931:DNA Primers / Q000737:chemistry; D018076:DNA, Complementary / Q000378:metabolism; D005786:Gene Expression Regulation; D018506:Gene Expression Regulation, Plant; D005982:Glutathione Transferase / Q000378:metabolism; D016695:Glycosyltransferases / Q000378:metabolism; D007700:Kinetics; D009841:Oligonucleotides / Q000737:chemistry; D054883:Oxylipins; D012150:Polymorphism, Restriction Fragment Length; D011401:Promoter Regions, Genetic; D012313:RNA / Q000378:metabolism; D017382:Reactive Oxygen Species; D020156:Salicylic Acid / Q000378:metabolism; D015398:Signal Transduction; D013696:Temperature; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D017931:DNA Primers; D018076:DNA, Complementary; C105496:NPR1 protein, Arabidopsis; D009841:Oligonucleotides; D054883:Oxylipins; D017382:Reactive Oxygen Species; D014157:Transcription Factors; D012313:RNA; C011006:jasmonic acid; D016695:Glycosyltransferases; D005982:Glutathione Transferase; D020156:Salicylic Acid