Nitrite as the major source of nitric oxide production by Arabidopsis thaliana in response to Pseudomonas syringae

FEBS Lett. 2005 Jul 4;579(17):3814-20. doi: 10.1016/j.febslet.2005.05.078.

Abstract

The origin of nitric oxide (*NO) in plants is unclear and an *NO synthase (NOS)-like enzyme and nitrate reductase (NR) are claimed as potential sources. Here we used wild-type and NR-defective double mutant plants to investigate *NO production in Arabidopsis thaliana in response to Pseudomonas syringae pv maculicola. NOS activity increased substantially in leaves inoculated with P. syringae. However, electron paramagnetic resonance experiments showed a much higher *NO formation that was dependent on nitrite and mitochondrial electron transport rather than on arginine or nitrate. Overall, these results indicate that NOS, NR and a mitochondrial-dependent nitrite-reducing activity cooperate to produce *NO during A. thaliana-P. syringae interaction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / enzymology*
  • Arabidopsis / genetics
  • Arabidopsis / microbiology*
  • Electron Spin Resonance Spectroscopy
  • Mutation
  • Nitrate Reductase
  • Nitrate Reductases / genetics
  • Nitrate Reductases / metabolism*
  • Nitric Oxide / biosynthesis*
  • Nitric Oxide Synthase / genetics
  • Nitric Oxide Synthase / metabolism*
  • Nitrites / metabolism*
  • Plant Leaves / enzymology
  • Plant Leaves / genetics
  • Plant Leaves / microbiology
  • Pseudomonas syringae / physiology*

Substances

  • Nitrites
  • Nitric Oxide
  • Nitric Oxide Synthase
  • Nitrate Reductases
  • Nitrate Reductase