title: Overexpression of Elsholtzia haichowensis metallothionein 1 (EhMT1) in tobacco plants enhances copper tolerance and accumulation in root cytoplasm and decreases hydrogen peroxide production.
abstract: To evaluate the functional roles of metallothionein (MT) in copper tolerance, we generated transgenic tobacco plants overexpressing EhMT1 from the Cu-accumulator Elsholtzia haichowensis Sun. Overexpression of EhMT1 in tobacco plants imparted increased copper (Cu) tolerance based on seedling dry biomass when compared to wild-type plants. Plants expressing EhMT1 accumulated more Cu in roots, which was mainly attributable to an increase of the soluble fraction. Levels of lipid peroxidation and production of hydrogen peroxide were lower in roots of transgenic tobacco than in wild-type plants. EhMT1 was suggested to bind Cu in the cytoplasm, thereby decreasing activity of free Cu(2+) ions and blocking Cu(2+) from interacting with cytoplasmic components, which in turn decreases the production of reactive oxygen species. In addition, our results also indicate that EhMT1-overexpressing tobacco has a more efficient antioxidant system, with improved peroxidase activity to better cope with oxidative stress.
authors: College of Life Sciences, Nanjing Agricultural University, Nanjing, PR China.
authors: Yan
authors: Y
authors: Xia
authors: Ying
authors: Y
authors: Qi
authors: Yuxiang
authors: Y
authors: Yuan
authors: Guiping
authors: G
authors: Wang
authors: Jin
authors: J
authors: Cui
authors: Yahua
authors: Y
authors: Chen
authors: Hongsheng
authors: H
authors: Zhang
authors: Zhenguo
authors: Z
authors: Shen
mesh_terms: D003300:Copper / Q000494:pharmacology*; D003593:Cytoplasm / Q000187:drug effects / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D006861:Hydrogen Peroxide / Q000378:metabolism*; D019686:Lamiaceae; D008668:Metallothionein / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D018520:Plant Shoots / Q000187:drug effects / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D014026:Nicotiana / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*
chemical_list: D018076:DNA, Complementary; D010940:Plant Proteins; D003300:Copper; D008668:Metallothionein; D006861:Hydrogen Peroxide