Journal
NITRIC OXIDE-BIOLOGY AND CHEMISTRY
Volume 5, Issue 3, Pages 261-270Publisher
ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1006/niox.2001.0353
Keywords
alternative oxidase; ATP synthesis; cytochrome oxidase; mitochondria; nitric oxide
Categories
Ask authors/readers for more resources
Plant nitrate reductase (NR) produces nitric oxide (NO) when nitrite is provided as the substrate in the presence of NADH [H. Yamasaki and Y. Sakihama (2000) FEBS Lett. 468, 89-92]. Using a NR-dependent NO producing system, we investigated the effects of NO on the energy transduction system in plant mitochondria isolated from mung bean (Vigna radiata). Plant mitochondria are known to possess two respiratory electron transport pathways-the cytochrome and alternative pathways. When the alternative pathway was inhibited by n-propyl gallate, the addition of NR strongly suppressed respiratory O-2 consumption driven by the cytochrome pathway. In contrast, the alternative pathway measured in the presence of antimycin A was not affected by NO. The extent of the steady-state membrane potential (Delta psi) generated by respiratory electron transport rapidly declined in response to NO production. The addition of bovine hemoglobin, a quencher of NO, resulted in the recovery of Delta psi to the uninhibited level. Consistent with its inhibition of Delta psi, NO produced by NR strongly suppressed ATP synthesis in the mitochondria. These results provide substantial evidence to confirm that the plant alternative pathway is resistant to NO and support the idea that the alternative pathway may lower respiration-dependent production of active oxygens under conditions where NO is overproduced, (C) 2001 Academic Press
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available