title: Acquisition of aluminium tolerance by modification of a single gene in barley.
abstract: Originating from the Fertile Crescent in the Middle East, barley has now been cultivated widely on different soil types including acid soils, where aluminium toxicity is a major limiting factor. Here we show that the adaptation of barley to acid soils is achieved by the modification of a single gene (HvAACT1) encoding a citrate transporter. We find that the primary function of this protein is to release citrate from the root pericycle cells to the xylem to facilitate the translocation of iron from roots to shoots. However, a 1-kb insertion in the upstream of the HvAACT1 coding region occurring only in the Al-tolerant accessions, enhances its expression and alters the location of expression to the root tips. The altered HvAACT1 has an important role in detoxifying aluminium by secreting citrate to the rhizosphere. Thus, the insertion of a 1-kb sequence in the HvAACT1 upstream enables barley to adapt to acidic soils.
authors.affiliation: Institute of Plant Science and Resources, Okayama University, Kurashiki 710-0046, Japan.
authors.forename: Miho
authors.initials: M
authors.lastname: Fujii
authors.forename: Kengo
authors.initials: K
authors.lastname: Yokosho
authors.forename: Naoki
authors.initials: N
authors.lastname: Yamaji
authors.forename: Daisuke
authors.initials: D
authors.lastname: Saisho
authors.forename: Miki
authors.initials: M
authors.lastname: Yamane
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Takahashi
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Sato
authors.forename: Mikio
authors.initials: M
authors.lastname: Nakazono
authors.forename: Jian Feng
authors.initials: JF
authors.lastname: Ma
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D000535:Aluminum / Q000378:metabolism / Q000633:toxicity*; D001483:Base Sequence; D001692:Biological Transport; D002352:Carrier Proteins / Q000235:genetics*; D019343:Citric Acid / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D001467:Hordeum / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000378:metabolism; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D018517:Plant Roots / Q000378:metabolism; D030821:Plants, Genetically Modified; D058441:Rhizosphere; D017422:Sequence Analysis, DNA; D012987:Soil / Q000737:chemistry; D052584:Xylem / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D012987:Soil; C020723:citrate-binding transport protein; D019343:Citric Acid; D000535:Aluminum; D007501:Iron