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Showing papers in "Plant and Cell Physiology in 1981"


Journal ArticleDOI
TL;DR: Observations confirm that the electron donor for the scavenging of hydrogen peroxide in chloroplasts is L-ascorbate and that the L-ASCorbate is regenerated from DHA by the system: photosystem I-*ferredoxin-*NADP^>glutathione and a preliminary characterization of the chloroplast peroxidase is given.
Abstract: Intact spinach chloroplasts scavenge hydrogen peroxide with a peroxidase that uses a photoreductant as the electron donor, but the activity of ruptured chloroplasts is very low [Nakano and Asada (1980) Plant & Cell Physiol. 21: 1295]. Ruptured spinach chloroplasts recovered their ability to photoreduce hydrogen peroxide with the concomitant evolution of oxygen after the addition of glutathione and dehydroascorbate (DHA). In ruptured chloroplasts, DHA was photoreduced to ascorbate and oxygen was evolved in the process in the presence of glutathione. DHA reductase (EC 1.8.5.1) and a peroxidase whose electron donor is specific to L-ascorbate are localized in chloroplast stroma. These observations confirm that the electron donor for the scavenging of hydrogen peroxide in chloroplasts is L-ascorbate and that the L-ascorbate is regenerated from DHA by the system: photosystem I-*ferredoxin-*NADP^>glutathione. A preliminary characterization of the chloroplast peroxidase is given.

8,406 citations