title: Nitric oxide- and hydrogen peroxide-responsive gene regulation during cell death induction in tobacco.
abstract: Nitric oxide (NO) and hydrogen peroxide (H(2)O(2)) are regulatory molecules in various developmental processes and stress responses. Tobacco (Nicotiana tabacum) leaves exposed to moderate high light dramatically potentiated NO-mediated cell death in catalase-deficient (CAT1AS) but not in wild-type plants, providing genetic evidence for a partnership between NO and H(2)O(2) during the induction of programmed cell death. With this experimental model system, the specific impact on gene expression was characterized by either NO or H(2)O(2) alone or both molecules combined. By means of genome-wide cDNA-amplified fragment length polymorphism analysis, transcriptional changes were compared in high light-treated CAT1AS and wild-type leaves treated with or without the NO donor sodium nitroprusside. Differential gene expression was detected for 214 of the approximately 8,000 transcript fragments examined. For 108 fragments, sequence analysis revealed homology to genes with a role in signal transduction, defense response, hormone interplay, proteolysis, transport, and metabolism. Surprisingly, only 16 genes were specifically induced by the combined action of NO and H(2)O(2), whereas the majority were regulated by either of them alone. At least seven transcription factors were mutually up-regulated, indicating significant overlap between NO and H(2)O(2) signaling pathways. These results consolidate significant cross-talk between NO and H(2)O(2), provide new insight into the early transcriptional response of plants to increased NO and H(2)O(2) levels, and identify target genes of the combined action of NO and H(2)O(2) during the induction of plant cell death.
authors.affiliation: Department of Plant Systems Biology, Flanders Interuniversity Institute for Biotechnology, Ghent University, B-9052 Ghent, Belgium.
authors.forename: Elisa
authors.initials: E
authors.lastname: Zago
authors.forename: Stijn
authors.initials: S
authors.lastname: Morsa
authors.forename: James F
authors.initials: JF
authors.lastname: Dat
authors.forename: Philippe
authors.initials: P
authors.lastname: Alard
authors.forename: Alberto
authors.initials: A
authors.lastname: Ferrarini
authors.forename: Dirk
authors.initials: D
authors.lastname: Inzé
authors.forename: Massimo
authors.initials: M
authors.lastname: Delledonne
authors.forename: Frank
authors.initials: F
authors.lastname: Van Breusegem
mesh_terms: D001483:Base Sequence; D016923:Cell Death; D017931:DNA Primers; D018076:DNA, Complementary; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008969:Molecular Sequence Data; D009569:Nitric Oxide / Q000378:metabolism*; D018515:Plant Leaves / Q000166:cytology / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014026:Nicotiana / Q000166:cytology / Q000235:genetics / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D009569:Nitric Oxide; D006861:Hydrogen Peroxide