title: Implication of the oep16-1 mutation in a flu-independent, singlet oxygen-regulated cell death pathway in Arabidopsis thaliana.
abstract: Singlet oxygen is a prominent form of reactive oxygen species in higher plants. It is easily formed from molecular oxygen by triplet-triplet interchange with excited porphyrin species. Evidence has been obtained from studies on the flu mutant of Arabidopsis thaliana of a genetically determined cell death pathway that involves differential changes at the transcriptome level. Here we report on a different cell death pathway that can be deduced from the analysis of oep16 mutants of A. thaliana. Pure lines of four independent OEP16-deficient mutants with different cell death properties were isolated. Two of the mutants overproduced free protochlorophyllide (Pchlide) in the dark because of defects in import of NADPH:Pchlide oxidoreductase A (pPORA) and died after illumination. The other two mutants avoided excess Pchlide accumulation. Using pulse labeling and polysome profiling studies we show that translation is a major site of cell death regulation in flu and oep16 plants. flu plants respond to photooxidative stress triggered by singlet oxygen by reprogramming their translation toward synthesis of key enzymes involved in jasmonic acid synthesis and stress proteins. In contrast, those oep16 mutants that were prone to photooxidative damage were unable to respond in this way. Together, our results show that translation is differentially affected in the flu and oep16 mutants in response to singlet oxygen.
authors.affiliation: Université Joseph Fourier, Grenoble cedex 9, France.
authors.forename: Iga
authors.initials: I
authors.lastname: Samol
authors.forename: Frank
authors.initials: F
authors.lastname: Buhr
authors.forename: Armin
authors.initials: A
authors.lastname: Springer
authors.forename: Stephan
authors.initials: S
authors.lastname: Pollmann
authors.forename: Abder
authors.initials: A
authors.lastname: Lahroussi
authors.forename: Claudia
authors.initials: C
authors.lastname: Rossig
authors.forename: Diter
authors.initials: D
authors.lastname: von Wettstein
authors.forename: Christiane
authors.initials: C
authors.lastname: Reinbothe
authors.forename: Steffen
authors.initials: S
authors.lastname: Reinbothe
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics*; D016923:Cell Death; D007473:Ion Channels / Q000235:genetics*; D009154:Mutation; D026082:Singlet Oxygen / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D007473:Ion Channels; C512221:OEP16-L protein, Arabidopsis; D026082:Singlet Oxygen