title: Functional analysis of metal tolerance proteins isolated from Zn/Cd hyperaccumulating ecotype and non-hyperaccumulating ecotype of Sedum alfredii Hance.
abstract: The Zn/Cd hyperaccumulating ecotype (HE) of Sedum alfredii Hance can accumulate 24- and 28-fold higher leaf and stem Zn concentrations when compared with the non-hyperaccumulating ecotype (NHE) of Sedum. Heterologous expression of a metal tolerance protein (MTP1) encoding gene from HE plants (SaMTP1) or the homologous gene from NHE plants (SnMTP1) suppressed Zn(2+) hypersensitivity in the Δzrc1 yeast mutant. In plants, SaMTP1 localized to the tonoplast. Furthermore, MTP1 transcript level in the shoot of HE plants was more than 80-fold higher than that of NHE plants. The transcript level of SaMTP1 in shoot was up-regulated 1-fold by Zn(2+) while the expression of SnMTP1 was slightly inhibited. These data suggest that SaMTP1 can play an important role in Zn accumulation in HE plants.
authors.affiliation: MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang, China.
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.forename: Takeshi
authors.initials: T
authors.lastname: Senoura
authors.forename: Xiaoe
authors.initials: X
authors.lastname: Yang
authors.forename: Naoko K
authors.initials: NK
authors.lastname: Nishizawa
mesh_terms: D000595:Amino Acid Sequence; D002104:Cadmium / Q000378:metabolism* / Q000633:toxicity; D003001:Cloning, Molecular; D018506:Gene Expression Regulation, Plant; D042541:Intracellular Space / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000166:cytology; D031963:Sedum / Q000166:cytology / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D015032:Zinc / Q000378:metabolism* / Q000633:toxicity
chemical_list: D010940:Plant Proteins; D002104:Cadmium; D015032:Zinc