Plant Physiol. Tips for Better Browsing
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Plant Physiology 65:703-706 (1980)
© 1980 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 CrossRef
Right arrow Citing Articles via Web of Science (8)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Marsho, T. V.
Right arrow Articles by MacKay, A. B.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Marsho, T. V.
Right arrow Articles by MacKay, A. B.
Agricola
Right arrow Articles by Marsho, T. V.
Right arrow Articles by MacKay, A. B.
Articles

Regulation of Photosynthetic Electron Transport in Intact Spinach Chloroplasts

I. INFLUENCE OF EXOGENOUS SALTS ON OXALOACETATE REDUCTION 1,2

Thomas V. Marsho, Patricia M. Sokolove and A. Bryan MacKay

Department of Biological Sciences, University of Maryland Baltimore County, (UMBC) Catonsville, Maryland 21228

Relatively high concentrations of monovalent salts (150 millimolar) stimulated light-saturated uncoupled rates of O2 evolution linked to oxaloacetic acid (OAA) reduction by intact chloroplasts 2-to 3-fold. In contrast, monovalent salts partially inhibited light-saturated rates of O2 evolution coupled to CO2 fixation and uncoupled rates of nitrite reduction. In the presence of high salt concentration, light-saturated rates of electron transport were about equivalent for all three terminal electron acceptors. It is inferred that exogenous monovalent salts have at least two effects on photosynthetic electron transport, independent of photophosphorylation and CO2 metabolism: a partial inhibitory effect common to OAA, NO2– and CO2 reduction and a marked stimulatory effect unique to the photoreduction of OAA.

The stimulation of electron transport to OAA was effected by certain exogenous monovalent salts (KCl or NaCl, but not LiCl). Divalent salts (MgCl2 or CaCl2) and high osmotic strength were ineffective. The salt-induced stimulation was eliminated by low concentrations of phosphate or sulfate (≥ millimolar) and by higher concentrations of magnesium (≥30 millimolar). These results suggest that the ion content of the medium (or cytosol) is potentially important in modulating photosynthetic electron transport events in intact chloroplasts.

1 This research was supported in part by grants from the National Science Foundation (GB-38237) and the Science and Education Administration of the United States Department of Agriculture under Grant 7801019 from the Competitive Research Grants Office.

2 This paper is dedicated to Bessel Kok, an imaginative researcher, an inspiring teacher, and a good friend (T. V. M.).






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
ASPB Publications PLANT PHYSIOLOGY® THE PLANT CELL
Copyright © 1980 by the American Society of Plant Biologists