title: The metallothionein gene, TaMT3, from Tamarix androssowii confers Cd2+ tolerance in tobacco.
abstract: Cadmium (Cd) is a nonessential microelement and low concentration Cd2+ has strong toxicity to plant growth. Plant metallothioneins, a class of low molecular, cystein(Cys)-rich and heavy-metal binding proteins, play an important role in both metal chaperoning and scavenging of reactive oxygen species (ROS) with their large number of cysteine residues and therefore, protect plants from oxidative damage. In this study, a metallothionein gene, TaMT3, isolated from Tamarix androssowii was transformed into tobacco (Nicotiana tobacum) through Agrobacterium-mediated leaf disc method, and correctly expressed under the control of 35S promoter. Under Cd2+ stress, the transgenic tobacco showed significant increases of superoxide dismutase (SOD) activity and chlorophyll concentration, but decreases of peroxidase (POD) activity and malondialdehyde (MDA) accumulation when compared to the non-transgenic tobacco. Vigorous growth of transgenic tobacco was observed at the early development stages, resulting in plant height and fresh weight were significantly larger than those of the non-transgenic tobacco under Cd2+ stress. These results demonstrated that the expression of the exogenous TaMT3 gene increased the ability of ROS cleaning-up, indicating a stronger tolerance to Cd2+ stress.
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China. boruzhou@yahoo.com.
authors.forename: Boru
authors.initials: B
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China. wenjingyao20140408@gmail.com.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Yao
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China. shengjinefu@gmail.com.
authors.forename: Shengji
authors.initials: S
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China. wlywing@yahoo.com.
authors.forename: Xinwang
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China. tbjiang@yahoo.com.
authors.forename: Tingbo
authors.initials: T
authors.lastname: Jiang
mesh_terms: D060054:Agrobacterium / Q000235:genetics; D000595:Amino Acid Sequence; D001483:Base Sequence; D002104:Cadmium / Q000633:toxicity*; D002734:Chlorophyll / Q000378:metabolism; D008315:Malondialdehyde / Q000378:metabolism; D008668:Metallothionein / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D010544:Peroxidases / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D032363:Tamaricaceae / Q000378:metabolism*; D014026:Nicotiana / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D017382:Reactive Oxygen Species; D002104:Cadmium; D002734:Chlorophyll; D008315:Malondialdehyde; D008668:Metallothionein; D010544:Peroxidases; D013482:Superoxide Dismutase