Identification and characterization of zinc-starvation-induced ZIP transporters from barley roots

Plant Physiol Biochem. 2009 May;47(5):377-83. doi: 10.1016/j.plaphy.2009.01.006. Epub 2009 Feb 7.

Abstract

Zinc (Zn) is an essential element for plants but limited information is currently available on the molecular basis for Zn(2+) transport in crop species. To expand the knowledge on Zn(2+) transport in barley (Hordeum vulgare L.), a cDNA library prepared from barley roots was expressed in the yeast (Saccharomyces cerevisiae) mutant strain Deltazrt1/Deltazrt2, defective in Zn(2+) uptake. This strategy resulted in isolation and identification of three new Zn(2+) transporters from barley. All of the predicted proteins have a high similarity to the ZIP protein family, and are designated HvZIP3, HvZIP5 and HvZIP8, respectively. Complementation studies in Deltazrt1/Deltazrt2 showed restored growth of the yeast cells transformed with the different HvZIPs, although with different efficiency. Transformation into Fe(2+) and Mn(2+) uptake defective yeast mutants showed that the HvZIPs were unable to restore the growth on Fe(2+) and Mn(2+) limited media, respectively, indicating a specific role in Zn(2+) transport. In intact barley roots, HvZIP8 was constitutively expressed whereas HvZIP3 and HvZIP5 were mainly expressed in -Zn plants. These results suggest that HvZIP3, HvZIP5 and HvZIP8 are Zn(2+) transporters involved in Zn(2+) homeostasis in barley roots. The new transporters may facilitate breeding of barley genotypes with improved Zn efficiency and Zn content.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Carrier Proteins / classification
  • Carrier Proteins / genetics*
  • Carrier Proteins / metabolism
  • Cation Transport Proteins / genetics*
  • Cation Transport Proteins / metabolism
  • Gene Expression Regulation, Plant
  • Genetic Complementation Test
  • Hordeum / genetics*
  • Hordeum / metabolism
  • Ion Transport
  • Iron / metabolism
  • Manganese / metabolism
  • Molecular Sequence Data
  • Mutation
  • Phylogeny
  • Plant Proteins / genetics*
  • Plant Proteins / metabolism
  • Plant Roots / genetics*
  • Plant Roots / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism
  • Sequence Homology, Amino Acid
  • Zinc / metabolism*

Substances

  • Carrier Proteins
  • Cation Transport Proteins
  • Plant Proteins
  • zinc-binding protein
  • Manganese
  • Iron
  • Zinc

Associated data

  • GENBANK/FJ208991
  • GENBANK/FJ208992
  • GENBANK/FJ208993