Journal Article

Nitric Oxide Production Mediated by Nitrate Reductase in the Green Alga <i>Chlamydomonas reinhardtii</i>: an Alternative NO Production Pathway in Photosynthetic Organisms

Yasuko Sakihama, Soichi Nakamura and Hideo Yamasaki

in Plant and Cell Physiology

Published on behalf of Japanese Society of Plant Physiologists

Volume 43, issue 3, pages 290-297
Published in print March 2002 | ISSN: 0032-0781
Published online March 2002 | e-ISSN: 1471-9053 | DOI: http://dx.doi.org/10.1093/pcp/pcf034
Nitric Oxide Production Mediated by Nitrate Reductase in the Green Alga Chlamydomonas reinhardtii: an Alternative NO Production Pathway in Photosynthetic Organisms

More Like This

Show all results sharing these subjects:

  • Biochemistry
  • Molecular and Cell Biology
  • Plant Sciences and Forestry

GO

Show Summary Details

Preview

Biological activity of nitric oxide (NO) production was investigated in the unicellular green alga Chlamydomonas reinhardtii. An NO specific electrode detected a rapid increase in signal when nitrite (NO2) was added into a suspension of C. reinhardtii intact cells in the dark. The addition of KCN or the NO quencher bovine hemoglobin completely abolished the signal, verifying that the nitrite-dependent increase in signal is due to enzymatic NO production. l-arginine, the substrate for NO synthase, did not induce detectable NO production and the NOS inhibitor Nω-nitro-l-arginine showed no inhibitory effect on the nitrite-dependent production of NO. Illuminating cells showed a significant suppressive effect on NO production. When the photosynthetic electron transport inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea was present in the suspension, C. reinhardtii cells produced NO after the addition of nitrite even under illumination. Kinetic and microscopic observations, using the intracellular fluorescent NO probe 4,5-diaminofluorescein-2 diacetate, both demonstrated that NO was produced within the cells in response to the addition of nitrite. The Chlamydomonas mutant cc-2929, which lacks nitrate reductase (NR) activity, did not display any of the responses observed in the wild-type cells. The results presented here provide direct in vivo evidence to confirm that NR is involved in the nitrite-dependent NO production in the green alga.

Keywords: Key words: Chlamydomonas — Nitrate reductase — Nitric oxide — Nitric oxide synthase — Nitrogen assimilation — Photosynthesis.; Abbreviations: DAF-2DA; 4,5-diaminofluorescein-2 diacetate, l-NNA; Nω-nitro-l-arginine, NR; nitrate reductase, NO; nitric oxide, NOS; NO synthase.

Journal Article.  6009 words.  Illustrated.

Subjects: Biochemistry ; Molecular and Cell Biology ; Plant Sciences and Forestry

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.