title: A novel cis-element that is responsive to oxidative stress regulates three antioxidant defense genes in rice.
abstract: All organisms have defense systems against oxidative stress that include multiple genes of antioxidant defense. These genes are induced by reactive oxygen species under condition of oxidative stress. In this study, we found that a 28-bp motif is conserved on the promoter regions of three antioxidant defense genes in rice (Oryza sativa): cytosolic superoxide dismutase (sodCc1), cytosolic thioredoxin (trxh), and glutaredoxin (grx). We demonstrated that the 28-bp sequence acts as a cis-element responsive to oxidative stress by transient expression assay and designated it as CORE (coordinate regulatory element for antioxidant defense). The CORE was activated by methyl viologen treatment and induced a 3.1-fold increase in expression of the reporter gene, but it did not respond to hydrogen peroxide. The expressions of the sodCc1, trxh, and grx genes were coordinately induced by methyl viologen, suggesting that multiple genes involved in antioxidant defense are controlled by a common regulatory mechanism via CORE. Application of the mitogen-activated protein kinase kinase inhibitor caused the constitutive induction of the sodCc1, trxh, and grx genes and the activation of CORE without methyl viologen treatment. These results indicate that a mitogen-activated protein kinase cascade is involved in the gene regulation mediated by CORE.
authors.affiliation: Laboratory of Genetic Engineering, Graduate School of Agriculture, Kyoto Prefectural University, Shimogamo, Sakyo, Kyoto, 606-8522, Japan.
authors.forename: Shigefumi
authors.initials: S
authors.lastname: Tsukamoto
authors.forename: Shigeto
authors.initials: S
authors.lastname: Morita
authors.forename: Etsuko
authors.initials: E
authors.lastname: Hirano
authors.forename: Hideki
authors.initials: H
authors.lastname: Yokoi
authors.forename: Takehiro
authors.initials: T
authors.lastname: Masumura
authors.forename: Kunisuke
authors.initials: K
authors.lastname: Tanaka
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D001483:Base Sequence; D017124:Conserved Sequence; D018506:Gene Expression Regulation, Plant / Q000502:physiology*; D020935:MAP Kinase Signaling System / Q000502:physiology; D008969:Molecular Sequence Data; D012275:Oryza / Q000235:genetics* / Q000378:metabolism*; D018384:Oxidative Stress; D010269:Paraquat; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid
chemical_list: D000975:Antioxidants; D010269:Paraquat