title: Copper-induced hydrogen peroxide upregulation of a metallothionein gene, OsMT2c, from Oryza sativa L. confers copper tolerance in Arabidopsis thaliana.
abstract: Metallothioneins (MTs) are low-molecular-weight, cysteine-rich metal-binding proteins found in numerous genera and species, but their functions in abiotic stress tolerance remain unclear. Here, a MT gene from Oryza sativa, OsMT2c, was isolated and characterized, encoding a type 2 MT, and observed expression in the roots, leaf sheathes, and leaves, but only weak expression in seeds. OsMT2c was upregulated by copper (Cu) and hydrogen peroxide (H2O2) treatments. Excessive Cu elicited a rapid and sustained production and release of H2O2 in rice, and exogenous H2O2 scavengers N,N'-dimethylthiourea (DMTU) and ascorbic acid (Asc) decreased H2O2 production and OsMT2c expression. Furthermore, the expression of OsMT2c increased in the osapx2 mutant in which the H2O2 levels were higher than in wild-type (WT) plants. These results showed that Cu increased MT2c expression through the production and accumulation of Cu-induced H2O2 in O. sativa. In addition, the transgenic OsMT2c-overexpressing Arabidopsis displayed improved tolerance to Cu stress and exhibited increased reactive oxygen species (ROS) scavenging ability compared to WT and empty-vector (Ev) seedlings.
authors: College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, People's Republic of China.
authors: Jia
authors: J
authors: Liu
authors: College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, People's Republic of China.
authors: Xiaoting
authors: X
authors: Shi
authors: College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, People's Republic of China.
authors: Meng
authors: M
authors: Qian
authors: College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, People's Republic of China.
authors: Luqing
authors: L
authors: Zheng
authors: Asian Natural Environmental Science Center, The University of Tokyo, Tokyo 188-0002, Japan.
authors: Chunlan
authors: C
authors: Lian
authors: College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, People's Republic of China. Electronic address: yxia@njau.edu.cn.
authors: Yan
authors: Y
authors: Xia
authors: College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, People's Republic of China. Electronic address: zgshen@njau.edu.cn.
authors: Zhenguo
authors: Z
authors: Shen
mesh_terms: D017360:Arabidopsis / Q000187:drug effects* / Q000235:genetics; D003300:Copper / Q000494:pharmacology / Q000633:toxicity*; D017343:Genes, Plant; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008668:Metallothionein / Q000235:genetics*; D012275:Oryza / Q000235:genetics*; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics*; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D012639:Seeds / Q000187:drug effects / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D010940:Plant Proteins; D017382:Reactive Oxygen Species; D003300:Copper; D008668:Metallothionein; D006861:Hydrogen Peroxide
keywords: Copper stress; Hydrogen peroxide; ROS scavenging; Transgenic Arabidopsis