Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P30044 (antioxidant enzyme)
 8,037 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hydrogen peroxide (H(2)O(2)) plays a key role in the regulation of plant responses to various environmental stresses and modulates the expression of related genes including those encoding antioxidant enzymes. A wheat oxalate oxidase (OxO) gene was transformed and expressed in tobacco for production of H(2)O(2). The transgenic plants exhibited enhanced OxO activities and H(2)O(2) concentrations, which was blocked by inhibitors of OxO. The transgenic plants showed increased tolerance to methyl viologen (MV) or high light-induced oxidative stress in both short-time and long-time tests by measuring their maximal photochemical efficiency of PSII (F(v)/F(m)), ion leakage and malondialdehyde. Higher activities and transcripts of antioxidant enzymes (superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase) were observed in the transgenic plants compared to their wild-type controls under normal growth conditions. Pretreatments with inhibitors of OxO and scavenger of H(2)O(2) blocked the increase of tolerance to MV-induced or high light-induced oxidative stress, as well as the induction of antioxidant enzyme activities. Pretreatments with H(2)O(2) increased tolerance to oxidative stresses and antioxidant enzyme activities. It is suggested that H(2)O(2) produced by OxO in the transgenic tobacco plants triggers the signaling pathways to upregulate expressions of antioxidant enzyme genes, which in turn results in the increase of tolerance to MV-induced and high light-induced oxidative stresses.
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PMID:Increased tolerance to oxidative stress in transgenic tobacco expressing a wheat oxalate oxidase gene via induction of antioxidant enzymes is mediated by H2O2. 1950 66

Abscisic acid (ABA), H2O2 and nitric oxide (NO) are important signals in gene expression and physiological responses during plant adaptation to environmental stresses. The essential role of NR-derived NO production in ABA and H2O2 induced antioxidant enzymes were studied using transgenic tobacco plants over-expressing Stylosanthes guianensis 9-cis-epoxycartenoid dioxygenase gene (SgNCED1) for elevated ABA level, or over-expressing wheat oxalate oxidase gene (OxO) for elevated H2O2 level in comparison to the wild type. Compared to the wild type, higher levels of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and nitrate reductase (NR) activities and NO production were observed in all transgenic plants. For investigating the relationship of ABA, H2O2, and NR-produced NO in the induction of antioxidant enzyme activities, an inhibitor of ABA biosynthesis, scavengers of H2O2 and NO, and an inhibitor of NR were used in the experiments. The results indicate that H2O2-induced activities of SOD, CAT, and APX depends on NR-derived NO in OxO transgenic plants, while ABA-induced activities depends on H2O2 and NR-derived NO in SgNCED1 transgenic plants. Compared to unaltered nitrate reductase 2 (NIA2), NIA1 transcript was induced in both types of transgenic plants. It is suggested NR-derived NO is essential for ABA- or H2O2-induced antioxidant enzyme activities.
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PMID:Nitrate reductase (NR)-dependent NO production mediates ABA- and H2O2-induced antioxidant enzymes. 2424 69