Arabidopsis thaliana NADPH oxidoreductase homologs confer tolerance of yeasts toward the thiol-oxidizing drug diamide.
To isolate new plant genes involved in the defense against oxidative stress, an Arabidopsis cDNA library in a yeast expression vector was transformed into a yeast strain deficient in the YAP1 gene, which encodes a b-Zip transcription factor and regulates general stress response in yeasts. Cells from approximately 10(5) primary transformants were subjected to a tolerance screen toward the thiol-oxidizing drug diamide, which depletes the reduced glutathione in the cell. Four types of Arabidopsis cDNAs were isolated. Three of these cDNAs (P1, P2, and P4) belong to a plant zeta-crystallin family and P3 is an Arabidopsis homolog of isoflavonoid reductases. As such, all four isolated cDNAs are homologous to NADPH oxidoreductases. P1, P2, and P3 steady-state mRNAs accumulated rapidly in Arabidopsis plants under various oxidative stress conditions, such as treatment with paraquat, t-butylhydroperoxide, diamide, and menadione. The data suggested that proteins encoded by the isolated cDNAs play a distinct role in plant antioxidant defense and are possibly involved in NAD(P)/NAD(P)H homeostasis.
Babiychuk
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E
Laboratorium voor Genetica, Universiteit Gent, Belgium.
Kushnir
S
S
Belles-Boix
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E
Van Montagu
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M
Inzé
D
D
D000595:Amino Acid Sequence; D000818:Animals; D017360:Arabidopsis / Q000201:enzymology*; D001483:Base Sequence; D003001:Cloning, Molecular; D003459:Crystallins / Q000737:chemistry; D018076:DNA, Complementary; D018744:DNA, Plant / Q000737:chemistry / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics; D003958:Diamide / Q000494:pharmacology*; D004926:Escherichia coli; D017343:Genes, Plant; D006168:Guinea Pigs; D007891:Leishmania; D008969:Molecular Sequence Data; D009247:NADH, NADPH Oxidoreductases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019255:NADPH Oxidases; D016366:Open Reading Frames; D018384:Oxidative Stress; D011817:Rabbits; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics; D014170:Transformation, Genetic
D003459:Crystallins; D018076:DNA, Complementary; D018744:DNA, Plant; D004268:DNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; C086677:YAP1 protein, S cerevisiae; D003958:Diamide; D009247:NADH, NADPH Oxidoreductases; D019255:NADPH Oxidases