title: Molecular characterization of a rice metal tolerance protein, OsMTP1.
abstract: Rice (Oryza sativa L. 'Nipponbare') cDNA subtractive suppression hybridization (SSH) libraries constructed using cadmium (Cd)-treated seedling roots were screened to isolate Cd-responsive genes. A cDNA clone, encoding the rice homolog of Metal Tolerance Protein (OsMTP1), was induced by Cd treatment. Plant MTPs belong to cation diffusion facilitator (CDF) protein family, which are widespread in bacteria, fungi, plants, and animals. OsMTP1 heterologous expression in yeast mutants showed that OsMTP1 was able to complement the mutant strains' hypersensitivity to Ni, Cd, and Zn, but not other metals including Co and Mn. OsMTP1 expression increased tolerance to Zn, Cd, and Ni in wild-type yeast BY4741 during the exponential growth phase. OsMTP1 fused to green fluorescent protein was localized in onion epidermal cell plasma membranes, consistent with an OsMTP1 function in heavy metal transporting. OsMTP1 dsRNAi mediated by transgenic assay in rice seedlings resulted in heavy metal sensitivity and changed the heavy metal accumulation in different organs of mature rice under low-concentration heavy metal stress. Taken together, our results show that OsMTP1 is a bivalent cation transporter localized in the cell membrane, which is necessary for efficient translocation of Zn, Cd and other heavy metals, and maintain ion homeostasis in plant.
authors: Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, People's Republic of China.
authors: Lianyu
authors: L
authors: Yuan
authors: Songguang
authors: S
authors: Yang
authors: Baoxiu
authors: B
authors: Liu
authors: Mei
authors: M
authors: Zhang
authors: Keqiang
authors: K
authors: Wu
mesh_terms: D001692:Biological Transport; D002104:Cadmium / Q000378:metabolism / Q000494:pharmacology; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D003035:Cobalt / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant; D005816:Genetic Complementation Test; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D008345:Manganese / Q000494:pharmacology; D008670:Metals / Q000378:metabolism; D019216:Metals, Heavy / Q000378:metabolism / Q000494:pharmacology; D009154:Mutation; D009532:Nickel / Q000378:metabolism / Q000494:pharmacology; D019697:Onions / Q000378:metabolism; D012275:Oryza / Q000187:drug effects / Q000502:physiology*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism*; D030821:Plants, Genetically Modified; D036226:Seedlings / Q000187:drug effects / Q000235:genetics; D015003:Yeasts / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D015032:Zinc / Q000378:metabolism / Q000494:pharmacology
chemical_list: D027682:Cation Transport Proteins; D008670:Metals; D019216:Metals, Heavy; D010940:Plant Proteins; D002104:Cadmium; D049452:Green Fluorescent Proteins; D003035:Cobalt; D008345:Manganese; D009532:Nickel; D015032:Zinc