title: HvZIP7 mediates zinc accumulation in barley (Hordeum vulgare) at moderately high zinc supply.
abstract: High expression of zinc (Zn)-regulated, iron-regulated transporter-like protein (ZIP) genes increases root Zn uptake in dicots, leading to high accumulation of Zn in shoots. However, none of the ZIP genes tested previously in monocots could enhance shoot Zn accumulation. In this report, barley (Hordeum vulgare) HvZIP7 was investigated for its functions in Zn transport. The functions of HvZIP7 in planta were studied using in situ hybridization and transient analysis of subcellular localization with a green fluorescent protein (GFP) reporter. Transgenic barley lines overexpressing HvZIP7 were also generated to further understand the functions of HvZIP7 in metal transport. HvZIP7 is strongly induced by Zn deficiency, primarily in vascular tissues of roots and leaves, and its protein was localized in the plasma membrane. These properties are similar to its closely related homologs in dicots. Overexpression of HvZIP7 in barley plants increased Zn uptake when moderately high concentrations of Zn were supplied. Significantly, there was a specific enhancement of shoot Zn accumulation, with no measurable increase in iron (Fe), manganese (Mn), copper (Cu) or cadmium (Cd). HvZIP7 displays characteristics of low-affinity Zn transport. The unique function of HvZIP7 provides new insights into the role of ZIP genes in Zn homeostasis in monocots, and offers opportunities to develop Zn biofortification strategies in cereals.
authors.affiliation: Australian Centre for Plant Functional Genomics, The University of Adelaide, Hartley Grove, Urrbrae, SA, 5064, Australia.
authors.forename: Jingwen
authors.initials: J
authors.lastname: Tiong
authors.affiliation: School of Agriculture, Food and Wine, University of Adelaide, Glen Osmond, SA, 5064, Australia.
authors.forename: Glenn K
authors.initials: GK
authors.lastname: McDonald
authors.affiliation: School of Agriculture, Food and Wine, University of Adelaide, Glen Osmond, SA, 5064, Australia.
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Genc
authors.affiliation: Plant and Soil Science Section, Department of Agriculture and Ecology, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Pai
authors.initials: P
authors.lastname: Pedas
authors.affiliation: Australian Centre for Plant Functional Genomics, The University of Adelaide, Hartley Grove, Urrbrae, SA, 5064, Australia.
authors.forename: Julie E
authors.initials: JE
authors.lastname: Hayes
authors.affiliation: Australian Centre for Plant Functional Genomics, The University of Adelaide, Hartley Grove, Urrbrae, SA, 5064, Australia.
authors.forename: John
authors.initials: J
authors.lastname: Toubia
authors.affiliation: Australian Centre for Plant Functional Genomics, The University of Adelaide, Hartley Grove, Urrbrae, SA, 5064, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Langridge
authors.affiliation: Australian Centre for Plant Functional Genomics, The University of Adelaide, Hartley Grove, Urrbrae, SA, 5064, Australia.
authors.forename: Chun Y
authors.initials: CY
authors.lastname: Huang
mesh_terms: D001692:Biological Transport; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D027682:Cation Transport Proteins / Q000235:genetics* / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D015870:Gene Expression; D017343:Genes, Plant; D006706:Homeostasis; D001467:Hordeum / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D018520:Plant Shoots / Q000378:metabolism; D015032:Zinc / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D027682:Cation Transport Proteins; D010940:Plant Proteins; C017800:zinc-binding protein; D015032:Zinc
keywords: Hordeum vulgare (barley); ZIP; accumulation; low affinity; translocation; transporter; uptake; zinc (Zn)
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