title: Plasma membrane-localized Al-transporter from blue hydrangea sepals is a member of the anion permease family.
abstract: In hydrangea sepals, an aluminum complex of delphinidin-3-O-glucoside is responsible for the development of the blue color, and co-existing copigments mediate the solubilization and stabilization of the blue Al-anthocyanin complex which is localized in the sepal vacuole. In addition, hydrangeas are Al-hyperaccumulators and exhibit tolerance to acidic soils, in which the toxicity is due to soluble Al ion. Therefore, an Al-absorbing transport and storage system must exist in hydrangea. Recently, we cloned vacuolar and plasma membrane-localized Al-transporters, HmVALT, and HmPALT1, which are both members of the aquaporin family. However, HmPALT1 was only expressed in the sepals, indicating that a different Al-transporter should exist for absorption and long-distance transportation in the hydrangea plant. Using genetic information and microarray analysis, we identified an additional aluminum transporter gene, HmPALT2, which belongs to a member of the anion permease. The transcript was expressed in all tissues of hydrangea plants, and a transient expression study indicated that the gene product is localized to the plasma membrane. The results of an aluminum tolerance assay using yeast cells showed that the HmPALT2 is also involved in the transport of other metal(loid)s. The over-expression of HmPALT2 in Arabidopsis resulted in aluminum-hypersensitivity, suggesting that HmPALT2 should work as an aluminum transporter into cells in planta.
authors: Graduate School of Information Science, Nagoya University, Nagoya, Japan.
authors: Takashi
authors: T
authors: Negishi
authors: Kenshiro
authors: K
authors: Oshima
authors: Masahira
authors: M
authors: Hattori
authors: Kumi
authors: K
authors: Yoshida
mesh_terms: D000535:Aluminum / Q000378:metabolism*; D000838:Anions / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics; D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism*; D035264:Flowers / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D031966:Hydrangea / Q000235:genetics / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D005810:Multigene Family; D020411:Oligonucleotide Array Sequence Analysis; D030821:Plants, Genetically Modified; D021381:Protein Transport; D017422:Sequence Analysis, DNA; D013347:Subcellular Fractions / Q000201:enzymology; D013379:Substrate Specificity
chemical_list: D000838:Anions; D026901:Membrane Transport Proteins; D000535:Aluminum