RRC ID 47244
Author Wu D, Yamaji N, Yamane M, Kashino-Fujii M, Sato K, Feng Ma J.
Title The HvNramp5 Transporter Mediates Uptake of Cadmium and Manganese, But Not Iron.
Journal Plant Physiol
Abstract The Natural Resistance Associated Macrophage Protein (Nramp) represents a transporter family for metal ions in all organisms. Here, we functionally characterized a member of Nramp family in barley (Hordeum vulgare), HvNramp5. This member showed different expression patterns, transport substrate specificity, and cellular localization from its close homolog in rice (Oryza sativa), OsNramp5, although HvNramp5 was also localized to the plasma membrane. HvNramp5 was mainly expressed in the roots and its expression was not affected by Cd and deficiency of Zn, Cu, and Mn, but slightly up-regulated by Fe deficiency. Spatial expression analysis showed that the expression of HvNramp5 was higher in the root tips than that in the basal root regions. Furthermore, analysis with laser microdissection revealed higher expression of HvNramp5 in the outer root cell layers. HvNramp5 showed transport activity for both Mn2+ and Cd2+, but not for Fe2+ when expressed in yeast. Immunostaining with a HvNramp5 antibody showed that this protein was localized in the root epidermal cells without polarity. Knockdown of HvNramp5 in barley resulted in a significant reduction in the seedling growth at low Mn supply, but this reduction was rescued at high Mn supply. The concentration of Mn and Cd, but not other metals including Cu, Zn, and Fe, was decreased in both the roots and shoots of knockdown lines compared with the wild-type barley. These results indicate that HvNramp5 is a transporter required for uptake of Mn and Cd, but not for Fe, and that barley has a distinct uptake system from rice.
Volume 172(3)
Pages 1899-1910
Published 2016-11-1
DOI 10.1104/pp.16.01189
PII pp.16.01189
PMID 27621428
PMC PMC5100758
MeSH Biological Transport Cadmium / metabolism* Gene Expression Regulation, Plant Gene Knockdown Techniques Hordeum / genetics Hordeum / metabolism* Iron / metabolism* Manganese / metabolism* Membrane Transport Proteins / genetics Membrane Transport Proteins / metabolism* Oryza / metabolism Phenotype Phylogeny Plant Proteins / genetics Plant Proteins / metabolism* Plants, Genetically Modified RNA Interference Saccharomyces cerevisiae / metabolism Subcellular Fractions / metabolism
IF 6.902
Times Cited 62
Barley オオムギ系統