Simultaneous production of nitric oxide and peroxynitrite by plant nitrate reductase: in vitro evidence for the NR-dependent formation of active nitrogen species

FEBS Lett. 2000 Feb 18;468(1):89-92. doi: 10.1016/s0014-5793(00)01203-5.


We examined the ability of plant nitrate reductase (NR) to produce nitric oxide (NO) using in vitro assays. Electrochemical and fluorometric measurements both showed that NO is produced by corn NR in the presence of nitrite and NADH at pH 7. The NO production was inhibited by sodium azide, a known inhibitor for NR. During the reaction, absorbance of 2',7'-dichlorodihydrofluorescein increased markedly. This change was completely suppressed by sodium azide, glutathione or depletion of oxygen. We conclude that plant NR produces both NO and its toxic derivative, peroxynitrite, under aerobic conditions when nitrite is provided as the substrate for NR.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aerobiosis
  • Cell-Free System
  • Fluoresceins
  • Fluorescent Dyes
  • Glutathione / pharmacology
  • NAD / metabolism
  • Nitrate Reductases / antagonists & inhibitors
  • Nitrate Reductases / metabolism*
  • Nitrates / metabolism*
  • Nitric Oxide / analysis
  • Nitric Oxide / biosynthesis*
  • Nitrites / metabolism
  • Oxidants / biosynthesis*
  • Sodium Azide / pharmacology
  • Zea mays / enzymology*


  • 4,5-diamino-2-(3,6-dihydroxy-9H-xanthen-9-yl)benzoic acid
  • Fluoresceins
  • Fluorescent Dyes
  • Nitrates
  • Nitrites
  • Oxidants
  • NAD
  • 2',7'-dichlorodihydrofluorescein
  • peroxynitric acid
  • Nitric Oxide
  • Sodium Azide
  • Nitrate Reductases
  • Glutathione