Planta

, Volume 223, Issue 6, pp 1178–1190

Expression profiling of the Arabidopsis ferric chelate reductase (FRO) gene family reveals differential regulation by iron and copper

  • Indrani Mukherjee
  • Nathan H. Campbell
  • Joshua S. Ash
  • Erin L. Connolly
Original Article

DOI: 10.1007/s00425-005-0165-0

Cite this article as:
Mukherjee, I., Campbell, N.H., Ash, J.S. et al. Planta (2006) 223: 1178. doi:10.1007/s00425-005-0165-0

Abstract

The Arabidopsis FRO2 gene encodes the iron deficiency-inducible ferric chelate reductase responsible for reduction of iron at the root surface; subsequent transport of iron across the plasma membrane is carried out by a ferrous iron transporter (IRT1). Genome annotation has identified seven additional FRO family members in the Arabidopsis genome. We used real-time RT-PCR to examine the expression of each FRO gene in different tissues and in response to iron and copper limitation. FRO2 and FRO5 are primarily expressed in roots while FRO8 is primarily expressed in shoots. FRO6 and FRO7 show high expression in all the green parts of the plant. FRO3 is expressed at high levels in roots and shoots, and expression of FRO3 is elevated in roots and shoots of iron-deficient plants. Interestingly, when plants are Cu-limited, the expression of FRO6 in shoot tissues is reduced. Expression of FRO3 is induced in roots and shoots by Cu-limitation. While it is known that FRO2 is expressed at high levels in the outer layers of iron-deficient roots, histochemical staining of FRO3-GUS plants revealed that FRO3 is predominantly expressed in the vascular cylinder of roots. Together our results suggest that FRO family members function in metal ion homeostasis in a variety of locations in the plant.

KeywordsArabidopsis, Copper, Ferric chelate reductase, Ferric reductase oxidase, Iron deficiency

Abbreviations

FRO

Ferric reductase oxidase

IRT1

Iron-regulated transporter 1

NA

Nicotianamine

RT-PCR

Reverse transcription-polymerase chain reaction

Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  • Indrani Mukherjee
    • 1
  • Nathan H. Campbell
    • 1
  • Joshua S. Ash
    • 1
  • Erin L. Connolly
    • 1
  1. 1.Department of Biological Sciences, Coker Life SciencesUniversity of South CarolinaColumbiaUSA