Plant Physiol. Drug Metab Dispos
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Plant Physiology 86:688-692 (1988)
© 1988 American Society of Plant Biologists

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Web of Science (60)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Weger, H. G.
Right arrow Articles by Turpin, D. H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Weger, H. G.
Right arrow Articles by Turpin, D. H.
Agricola
Right arrow Articles by Weger, H. G.
Right arrow Articles by Turpin, D. H.
Metabolism and Enzymology

Ammonium Assimilation Requires Mitochondrial Respiration in the Light 1

A Study with the Green Alga Selenastrum minutum

Harold G. Weger, Douglas G. Birch, Ivor R. Elrifi and David H. Turpin

Department of Biology, Queen's University, Kingston, Ontario, Canada K7L 3N6

Mass spectrometric analysis of O2 and CO2 exchange in the green alga Selenastrum minutum (Naeg. Collins) provides evidence for the occurrence of mitochondrial respiration in light. Stimulation of amino acid synthesis by the addition of NH4Cl resulted in nearly a 250% increase in the rate of TCA cycle CO2 efflux in both light and dark. Ammonium addition caused a similar increase in cyanide sensitive O2 consumption in both light and dark. Anaerobiosis inhibited the CO2 release caused by NH4Cl. These results indicated that the cytochrome pathway of the mitochondrial electron transport chain was operative and responsible for the oxidation of a large portion of the NADH generated during the ammonium induced increase in TCA cycle activity. In the presence of DCMU, ammonium addition also stimulated net O2 consumption in the light. This implied that the Mehler reaction did not play a significant role in O2 consumption under our conditions. These results show that both the TCA cycle and the mitochondrial electron transport chain are capable of operation in the light and that an important role of mitochondrial respiration in photosynthesizing cells is the provision of carbon skeletons for biosynthetic reactions.

1 Supported by the Natural Sciences and Engineering Research Council of Canada.




This article has been cited by other articles:


Home page
 Plant Physiol.Home page
J. M. Martínez-Rivas and J. M. Vega
Purification and Characterization of NAD-Isocitrate Dehydrogenase from Chlamydomonas reinhardtii
Plant Physiology, September 1, 1998; 118(1): 249 - 255.
[Abstract] [Full Text]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
ASPB Publications PLANT PHYSIOLOGY® THE PLANT CELL
Copyright © 1988 by the American Society of Plant Biologists