A ferric-chelate reductase for iron uptake from soils

Nature. 1999 Feb 25;397(6721):694-7. doi: 10.1038/17800.

Abstract

Iron deficiency afflicts more than three billion people worldwide, and plants are the principal source of iron in most diets. Low availability of iron often limits plant growth because iron forms insoluble ferric oxides, leaving only a small, organically complexed fraction in soil solutions. The enzyme ferric-chelate reductase is required for most plants to acquire soluble iron. Here we report the isolation of the FRO2 gene, which is expressed in iron-deficient roots of Arabidopsis. FRO2 belongs to a superfamily of flavocytochromes that transport electrons across membranes. It possesses intramembranous binding sites for haem and cytoplasmic binding sites for nucleotide cofactors that donate and transfer electrons. We show that FRO2 is allelic to the frd1 mutations that impair the activity of ferric-chelate reductase. There is a nonsense mutation within the first exon of FRO2 in frd1-1 and a missense mutation within FRO2 in frd1-3. Introduction of functional FRO2 complements the frd1-1 phenotype in transgenic plants. The isolation of FRO2 has implications for the generation of crops with improved nutritional quality and increased growth in iron-deficient soils.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Arabidopsis
  • Biological Transport
  • Cloning, Molecular
  • FMN Reductase*
  • Genes, Plant
  • Iron / metabolism*
  • Membrane Glycoproteins / metabolism
  • Molecular Sequence Data
  • Mutation
  • NADH, NADPH Oxidoreductases / genetics*
  • NADH, NADPH Oxidoreductases / metabolism
  • NADPH Oxidase 2
  • NADPH Oxidases*
  • Plant Proteins / genetics*
  • Plant Proteins / metabolism
  • Plant Roots / metabolism
  • Plants, Genetically Modified
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sequence Homology, Amino Acid
  • Soil

Substances

  • Membrane Glycoproteins
  • Plant Proteins
  • Soil
  • Iron
  • FMN Reductase
  • NADH, NADPH Oxidoreductases
  • CYBB protein, human
  • NADPH Oxidase 2
  • NADPH Oxidases
  • ferric citrate iron reductase

Associated data

  • GENBANK/Y09851