Generation of Hydrogen Peroxide in Chloroplasts of Arabidopsis Overexpressing Glycolate Oxidase as an Inducible System to Study Oxidative Stress

• Published in: Plant physiology (Bethesda) 2008-10, Vol.148 (2), p.719-729
• Main Authors: Fahnenstich, Holger, Scarpeci, Telma E, Valle, Estela M, Flügge, Ulf-Ingo, Maurino, Verónica G
• Format: Article
• Language: English
• Subjects: Alcohol Oxidoreductases - genetics; Alcohol Oxidoreductases - metabolism; Anthocyanins - metabolism; Antioxidants - metabolism; Arabidopsis - enzymology; Arabidopsis - genetics; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Biochemical Processes and Macromolecular Structures; Biological and medical sciences; Chloroplasts; Chloroplasts - enzymology; Chloroplasts - genetics; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Plant; Genes, Plant; Genetic Vectors; Glycolates; Glyoxylates; Glyoxylates - metabolism; Hydrogen; Hydrogen Peroxide - metabolism; Leaves; Light; Oxidative Stress; Phenotype; Phenotypes; Plant growth; Plant physiology and development; Plants; Plants, Genetically Modified - enzymology; Plants, Genetically Modified - genetics; Reactive oxygen species; Recombinant Proteins - genetics; Recombinant Proteins - metabolism; RNA, Plant - genetics; Starch - metabolism; Transgenes
• ISSN: 0032-0889; 1532-2548; 1532-2548
• DOI: 10.1104/pp.108.126789

Arabidopsis (Arabidopsis thaliana) overexpressing glycolate oxidase (GO) in chloroplasts accumulates both hydrogen peroxide (H₂O₂) and glyoxylate. GO-overexpressing lines (GO plants) grown at 75 μmol quanta m⁻² s⁻¹ show retarded development, yellowish rosettes, and impaired photosynthetic performance, while at 30 μmol quanta m⁻² s⁻¹, this phenotype virtually disappears. The GO plants develop oxidative stress lesions under photorespiratory conditions but grow like wild-type plants under nonphotorespiratory conditions. GO plants coexpressing enzymes that further metabolize glyoxylate but still accumulate H₂O₂ show all features of the GO phenotype, indicating that H₂O₂ is responsible for the GO phenotype. The GO plants can complete their life cycle, showing that they are able to adapt to the stress conditions imposed by the accumulation of H₂O₂ during the light period. Moreover, the data demonstrate that a response to oxidative stress is installed, with increased expression and/or activity of known oxidative stress-responsive components. Hence, the GO plants are an ideal noninvasive model system in which to study the effects of H₂O₂ directly in the chloroplasts, because H₂O₂ accumulation is inducible and sustained perturbations can reproducibly be provoked by exposing the plants to different ambient conditions.