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


     

Plant Physiology 55:799-802 (1975)
© 1975 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 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 Google Scholar
Google Scholar
Right arrow Articles by Peavey, D. G.
Right arrow Articles by Gibbs, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Peavey, D. G.
Right arrow Articles by Gibbs, M.
Agricola
Right arrow Articles by Peavey, D. G.
Right arrow Articles by Gibbs, M.
Articles

Photosynthetic Enhancement Studied in Intact Spinach Chloroplasts 1

Dwight G. Peavey2 and Martin Gibbs

a Department of Biology, Brandeis University, Waltham, Massachusetts 02154

The Emerson enhancement effect was evaluated in the intact spinach (Spinacia oleracea var. Long Standing Bloomsdale) chloroplast by monitoring the uptake of 14CO2 during illumination by 640 nm and 720 nm lights. Low levels (about 10 µM) of fructose 1,6-diphosphate, ribose 5-phosphate, and glycerate 3-phosphate stimulated the rate of photosynthesis and abolished enhancement values observed in their absence. Concentrations of the two sugar phosphates at levels of 1 mM responded similarly. In contrast, 1 mM glycerate 3-phosphate inhibited the rate of photosynthesis and increased enhancement. The exchange of glycerate 3-phosphate for glyceraldehyde 3-phosphate was speculated to be a factor underlying the decrease in photosynthesis and the increase in enhancement. Glucose 6-phosphate, NADPH, and L-malate did not influence photosynthesis or enhancement.

The uncoupler, p-trifluoromethoxyphenylhydrazone, decreased the rate of photosynthesis but did not change the enhancement values. ATP (0.2 to 1 mM) had an occasional stimulating effect on CO2 fixation but no effect on enhancement. Magnesium ions inhibited photosynthesis and decreased the enhancement values. It was concluded that the enhancement phenomenon reflects events of the photosynthetic carbon reduction cycle as well as the photochemical act.

2 This study represents part of a thesis submitted by D. G. P. in partial fulfillment of the requirements for the M.A. degree in Biology at Brandeis University.

1 This research was supported generously by the National Science Foundation Grant GB 29126X.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
ASPB Publications PLANT PHYSIOLOGY THE PLANT CELL
Copyright © 1975 by the American Society of Plant Biologists