Cytosolic dehydroascorbate reductase is important for ozone tolerance in Arabidopsis thaliana.
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.
Yoshida
Seiji
S
Master's Program in Biosystem Studies, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577 Japan.
Tamaoki
Masanori
M
Shikano
Takeshi
T
Nakajima
Nobuyoshi
N
Ogawa
Daisuke
D
Ioki
Motohide
M
Aono
Mitsuko
M
Kubo
Akihiro
A
Kamada
Hiroshi
H
Inoue
Yasunori
Y
Saji
Hikaru
H
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
D012333:RNA, Messenger; D010126:Ozone; D010088:Oxidoreductases; C020666:glutathione dehydrogenase (ascorbate); D005978:Glutathione; D001205:Ascorbic Acid