GSNOR provides plant tolerance to iron toxicity via preventing iron-dependent nitrosative and oxidative cytotoxicity

Nat Commun. 2019 Aug 29;10(1):3896. doi: 10.1038/s41467-019-11892-5.


Iron (Fe) is essential for life, but in excess can cause oxidative cytotoxicity through the generation of Fe-catalyzed reactive oxygen species. It is yet unknown which genes and mechanisms can provide Fe-toxicity tolerance. Here, we identify S-nitrosoglutathione-reductase (GSNOR) variants underlying a major quantitative locus for root tolerance to Fe-toxicity in Arabidopsis using genome-wide association studies and allelic complementation. These variants act largely through transcript level regulation. We further show that the elevated nitric oxide is essential for Fe-dependent redox toxicity. GSNOR maintains root meristem activity and prevents cell death via inhibiting Fe-dependent nitrosative and oxidative cytotoxicity. GSNOR is also required for root tolerance to Fe-toxicity throughout higher plants such as legumes and monocots, which exposes an opportunity to address crop production under high-Fe conditions using natural GSNOR variants. Overall, this study shows that genetic or chemical modulation of the nitric oxide pathway can broadly modify Fe-toxicity tolerance.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / embryology*
  • Arabidopsis / genetics
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Cell Death
  • Drug Tolerance / physiology*
  • Genetic Loci
  • Genome-Wide Association Study
  • Glutathione Reductase / genetics
  • Glutathione Reductase / metabolism*
  • Haplotypes
  • Hydrogen Peroxide / metabolism
  • Hydrogen Peroxide / toxicity
  • Iron / metabolism*
  • Iron / toxicity*
  • Meristem / metabolism
  • Nitric Oxide / metabolism
  • Nitric Oxide / toxicity
  • Nitrosation
  • Oxidative Stress
  • Plant Roots / drug effects
  • Plant Roots / growth & development
  • Plant Roots / metabolism
  • Plants, Genetically Modified


  • Arabidopsis Proteins
  • Nitric Oxide
  • Hydrogen Peroxide
  • Iron
  • Glutathione Reductase
  • S-nitrosoglutathione reductase, Arabidopsis