title: Genome-wide analysis of hydrogen peroxide-regulated gene expression in Arabidopsis reveals a high light-induced transcriptional cluster involved in anthocyanin biosynthesis.
abstract: In plants, reactive oxygen species and, more particularly, hydrogen peroxide (H(2)O(2)) play a dual role as toxic by-products of normal cell metabolism and as regulatory molecules in stress perception and signal transduction. Peroxisomal catalases are an important sink for photorespiratory H(2)O(2). Using ATH1 Affymetrix microarrays, expression profiles were compared between control and catalase-deficient Arabidopsis (Arabidopsis thaliana) plants. Reduced catalase levels already provoked differences in nuclear gene expression under ambient growth conditions, and these effects were amplified by high light exposure in a sun simulator for 3 and 8 h. This genome-wide expression analysis allowed us to reveal the expression characteristics of complete pathways and functional categories during H(2)O(2) stress. In total, 349 transcripts were significantly up-regulated by high light in catalase-deficient plants and 88 were down-regulated. From this data set, H(2)O(2) was inferred to play a key role in the transcriptional up-regulation of small heat shock proteins during high light stress. In addition, several transcription factors and candidate regulatory genes involved in H(2)O(2) transcriptional gene networks were identified. Comparisons with other publicly available transcriptome data sets of abiotically stressed Arabidopsis revealed an important intersection with H(2)O(2)-deregulated genes, positioning elevated H(2)O(2) levels as an important signal within abiotic stress-induced gene expression. Finally, analysis of transcriptional changes in a combination of a genetic (catalase deficiency) and an environmental (high light) perturbation identified a transcriptional cluster that was strongly and rapidly induced by high light in control plants, but impaired in catalase-deficient plants. This cluster comprises the complete known anthocyanin regulatory and biosynthetic pathway, together with genes encoding unknown proteins.
authors.affiliation: Department of Plant Systems Biology, Flanders Interuniversity Institute for Biotechnology, Ghent University, Belgium.
authors.forename: Sandy
authors.initials: S
authors.lastname: Vanderauwera
authors.forename: Philip
authors.initials: P
authors.lastname: Zimmermann
authors.forename: Stéphane
authors.initials: S
authors.lastname: Rombauts
authors.forename: Steven
authors.initials: S
authors.lastname: Vandenabeele
authors.forename: Christian
authors.initials: C
authors.lastname: Langebartels
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Gruissem
authors.forename: Dirk
authors.initials: D
authors.lastname: Inzé
authors.forename: Frank
authors.initials: F
authors.lastname: Van Breusegem
mesh_terms: D000872:Anthocyanins / Q000096:biosynthesis* / Q000235:genetics; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism* / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics; D002374:Catalase / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant; D006360:Heat-Shock Proteins / Q000235:genetics; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008027:Light; D005810:Multigene Family; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D014158:Transcription, Genetic / Q000528:radiation effects
chemical_list: D000872:Anthocyanins; D029681:Arabidopsis Proteins; D006360:Heat-Shock Proteins; D006861:Hydrogen Peroxide; D002374:Catalase