Skip to main content
padlock icon - secure page this page is secure

Free Content A specific transporter for iron(III)–phytosiderophore in barley roots

Download Article:
 Download
(PDF 616.8 kb)
 
Summary

Iron acquisition of graminaceous plants is characterized by the synthesis and secretion of the iron-chelating phytosiderophore, mugineic acid (MA), and by a specific uptake system for iron(III)–phytosiderophore complexes. We identified a gene specifically encoding an iron–phytosiderophore transporter (HvYS1) in barley, which is the most tolerant species to iron deficiency among graminaceous plants. HvYS1 was predicted to encode a polypeptide of 678 amino acids and to have 72.7% identity with ZmYS1, a first protein identified as an iron(III)–phytosiderophore transporter in maize. Real-time RT-PCR analysis showed that the HvYS1 gene was mainly expressed in the roots, and its expression was enhanced under iron deficiency. In situ hybridization analysis of iron-deficient barley roots revealed that the mRNA of HvYS1 was localized in epidermal root cells. Furthermore, immunohistological staining with anti-HvYS1 polyclonal antibody showed the same localization as the mRNA. HvYS1 functionally complemented yeast strains defective in iron uptake on media containing iron(III)–MA, but not iron–nicotianamine (NA). Expression of HvYS1 in Xenopus oocytes showed strict specificity for both metals and ligands: HvYS1 transports only iron(III) chelated with phytosiderophore. The localization and substrate specificity of HvYS1 is different from those of ZmYS1, indicating that HvYS1 is a specific transporter for iron(III)–phytosiderophore involved in primary iron acquisition from soil in barley roots.
No References
No Citations
No Supplementary Data
No Article Media
No Metrics

Keywords: YS1 gene; epidermal cells of barley roots; iron(III)–phytosiderophore transporter; mugineic acid; nicotianamine; tolerance of iron deficiency

Document Type: Research Article

Affiliations: 1: Research Institute for Bioresources, Okayama University, Chuo 2-20-1, Kurashiki 710-0046, Japan 2: Faculty of Life Sciences, Toyo University, 1-1-1 Izumino, Itakura, Ora, Gunma 374-0113, Japan 3: Suntory Institute for Bioorganic Research, 1-1-1 Wakayamadai, Shimamoto-cho, Mishima-gun, Osaka 618-8503, Japan

Publication date: May 1, 2006

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more