title: Cytosolic dehydroascorbate reductase is important for ozone tolerance in Arabidopsis thaliana.
abstract: Dehydroascorbate reductase (DHAR) is a key component of the ascorbate recycling system. Three functional DHAR genes are encoded in the Arabidopsis genome. Ozone exposure increased the expression of the cytosolic DHAR (cytDHAR) gene alone. We characterized an Arabidopsis mutant with a deficient cytDHAR. The mutant completely lacked cytDHAR activity and was highly ozone sensitive. The amounts of total ascorbate and glutathione were similar in both lines, but the amount of apoplastic ascorbate in the mutant was 61.5% lower. These results indicate that the apoplastic ascorbate, which is generated through the reduction of DHA by cytDHAR, is important for ozone tolerance.
authors.affiliation: Master's Program in Biosystem Studies, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577 Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Yoshida
authors.forename: Masanori
authors.initials: M
authors.lastname: Tamaoki
authors.forename: Takeshi
authors.initials: T
authors.lastname: Shikano
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Nakajima
authors.forename: Daisuke
authors.initials: D
authors.lastname: Ogawa
authors.forename: Motohide
authors.initials: M
authors.lastname: Ioki
authors.forename: Mitsuko
authors.initials: M
authors.lastname: Aono
authors.forename: Akihiro
authors.initials: A
authors.lastname: Kubo
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kamada
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Inoue
authors.forename: Hikaru
authors.initials: H
authors.lastname: Saji
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000502:physiology; D001205:Ascorbic Acid / Q000378:metabolism; D003600:Cytosol / Q000201:enzymology*; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005978:Glutathione / Q000378:metabolism; D009154:Mutation; D010088:Oxidoreductases / Q000378:metabolism*; D010126:Ozone; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics
chemical_list: D012333:RNA, Messenger; D010126:Ozone; D010088:Oxidoreductases; C020666:glutathione dehydrogenase (ascorbate); D005978:Glutathione; D001205:Ascorbic Acid