title: Scavenging reactive oxygen species by rice dehydroascorbate reductase alleviates oxidative stresses in Escherichia coli.
abstract: Maintaining redox balance is one of the crucial requirements for a cell to endure stress from the outside. Dehydroascorbate reductase (DHAR; EC 1.8.5.1) plays an important role in the ascorbate-glutathione cycle; one of the major ROS scavenging systems in most known biological systems. A cDNA clone of the DHAR gene from Oryza sativa (OsDHAR) was isolated and overexpressed in Escherichia coli BL21 (DE3) strain from the pET-28a(+) expression vector. The OsDHAR transformed E. coli cells showed significantly higher DHAR activity and a lower level of ROS than the E. coli cells transformed by an empty pET-28a(+) vector. Also, the DHAR-overexpressing E. coli strain was more tolerant to oxidant- and heavy metal-mediated stress conditions than the control E. coli strain. The results suggest that the overexpressed rice DHAR gene effectively functions in a prokaryotic system and provide protection to various oxidative stresses.
authors.affiliation: Department of Biology, Kyungpook National University, Daegu 702-701, Korea.
authors.forename: Sun-Young
authors.initials: SY
authors.lastname: Shin
authors.forename: Il-Sup
authors.initials: IS
authors.lastname: Kim
authors.forename: Yul-Ho
authors.initials: YH
authors.lastname: Kim
authors.forename: Hyang-Mi
authors.initials: HM
authors.lastname: Park
authors.forename: Jang-Yong
authors.initials: JY
authors.lastname: Lee
authors.forename: Hong-Gyu
authors.initials: HG
authors.lastname: Kang
authors.forename: Ho-Sung
authors.initials: HS
authors.lastname: Yoon
mesh_terms: D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D012275:Oryza / Q000201:enzymology*; D018384:Oxidative Stress / Q000235:genetics*; D010088:Oxidoreductases / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: D017382:Reactive Oxygen Species; D010088:Oxidoreductases; C020666:glutathione dehydrogenase (ascorbate)