20840506
not annotated - annotated - LINNAEUS only
OsHMA3, a P1B-type of ATPase affects root-to-shoot cadmium translocation in rice by mediating efflux into vacuoles.
* The cadmium (Cd) over-accumulating rice (Oryza sativa) cv Cho-Ko-Koku was previously shown to have an enhanced rate of root-to-shoot Cd translocation. This trait is controlled by a single recessive allele located at qCdT7. * In this study, using positional cloning and transgenic strategies, heavy metal ATPase 3 (OsHMA3) was identified as the gene that controls root-to-shoot Cd translocation rates. The subcellular localization and Cd-transporting activity of the gene products were also investigated. * The allele of OsHMA3 that confers high root-to-shoot Cd translocation rates (OsHMA3mc) encodes a defective P(1B) -ATPase transporter. OsHMA3 fused to green fluorescent protein was localized to vacuolar membranes in plants and yeast. An OsHMA3 transgene complemented Cd sensitivity in a yeast mutant that lacks the ability to transport Cd into vacuoles. By contrast, OsHMA3mc did not complement the Cd sensitivity of this yeast mutant, indicating that the OsHMA3mc transport function was lost. * We propose that the root cell cytoplasm of Cd-overaccumulating rice plants has more Cd available for loading into the xylem as a result of the lack of OsHMA3-mediated transportation of Cd to the vacuoles. This defect results in Cd translocation to the shoots in higher concentrations. These data demonstrate the importance of vacuolar sequestration for Cd accumulation in rice.
Ann file
T1 Species 76 80 rice
N1 Reference T1 Taxonomy:4530
T2 Species 155 159;175 189 rice cv Cho-Ko-Koku
N2 Reference T2 Taxonomy:4530
T3 Species 161 173 Oryza sativa
N3 Reference T3 Taxonomy:4530
T5 Out-of-scope 852 857 yeast
T6 Out-of-scope 912 917 yeast
T7 Out-of-scope 1047 1052 yeast
T8 Species 1184 1188 rice
N8 Reference T8 Taxonomy:4530
T9 Species 1493 1497 rice
N9 Reference T9 Taxonomy:4530
N5 Reference T5 Taxonomy:147537 Saccharomycotina
N6 Reference T6 Taxonomy:147537 Saccharomycotina
N7 Reference T7 Taxonomy:147537 Saccharomycotina