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


     

This Article
Right arrow Full Text
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 (30)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Eichelmann, H.
Right arrow Articles by Laisk, A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Eichelmann, H.
Right arrow Articles by Laisk, A.
Agricola
Right arrow Articles by Eichelmann, H.
Right arrow Articles by Laisk, A.

Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase Content, Assimilatory Charge, and Mesophyll Conductance in Leaves1

Hillar Eichelmann and Agu Laisk*

Tartu Ülikooli Molekulaar-ja Rakubioloogia Instituut, Riia tn 23, Tartu, 51010, Estonia

The content of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) (Et; EC 4.1.1.39) measured in different-aged leaves of sunflower (Helianthus annuus) and other plants grown under different light intensities, varied from 2 to 75 µmol active sites m-2. Mesophyll conductance (µ) was measured under 1.5% O2, as well as postillumination CO2 uptake (assimilatory charge, a gas-exchange measure of the ribulose-1,5-bisphosphate pool). The dependence of µ on Et saturated at Et = 30 µmol active sites m-2 and µ = 11 mm s-1 in high-light-grown leaves. In low-light-grown leaves the dependence tended toward saturation at similar Et but reached a µ of only 6 to 8 mm s-1. µ was proportional to the assimilatory charge, with the proportionality constant (specific carboxylation efficiency) between 0.04 and 0.075 µM-1 s-1. Our data show that the saturation of the relationship between Et and µ is caused by three limiting components: (a) the physical diffusion resistance (a minor limitation), (b) less than full activation of Rubisco (related to Rubisco activase and the slower diffusibility of Rubisco at high protein concentrations in the stroma), and (c) chloroplast metabolites, especially 3-phosphoglyceric acid and free inorganic phosphate, which control the reaction kinetics of ribulose-1,5-bisphosphate carboxylation by competitive binding to active sites.

1   This work was supported by the Estonian Science Foundation (grant no. 1808).
*   Corresponding author; e-mail alaisk{at}ut.ee; fax 372-7-477-250.

Plant Physiol. (1999) 119: 179-190
Copyright Clearance Center:   0032-0889/99/119//12
© 1999 American Society of Plant Physiologists




This article has been cited by other articles:


Home page
 J Exp BotHome page
Y. Li, Y. Gao, X. Xu, Q. Shen, and S. Guo
Light-saturated photosynthetic rate in high-nitrogen rice (Oryza sativa L.) leaves is related to chloroplastic CO2 concentration
J. Exp. Bot., May 1, 2009; 60(8): 2351 - 2360.
[Abstract] [Full Text] [PDF]

Home page
 Plant Cell PhysiolHome page
A. Laisk, H. Eichelmann, V. Oja, E. Talts, and R. Scheibe
Rates and Roles of Cyclic and Alternative Electron Flow in Potato Leaves
Plant Cell Physiol., November 1, 2007; 48(11): 1575 - 1588.
[Abstract] [Full Text] [PDF]

Home page
 ANN BOT (LOND)Home page
I. TERASHIMA, T. ARAYA, S.-I. MIYAZAWA, K. SONE, and S. YANO
Construction and Maintenance of the Optimal Photosynthetic Systems of the Leaf, Herbaceous Plant and Tree: an Eco-developmental Treatise
Ann. Bot., February 1, 2005; 95(3): 507 - 519.
[Abstract] [Full Text] [PDF]

Home page
 Plant Physiol.Home page
C. J. Bernacchi, A. R. Portis, H. Nakano, S. von Caemmerer, and S. P. Long
Temperature Response of Mesophyll Conductance. Implications for the Determination of Rubisco Enzyme Kinetics and for Limitations to Photosynthesis in Vivo
Plant Physiology, December 1, 2002; 130(4): 1992 - 1998.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
ASPB Publications PLANT PHYSIOLOGY® THE PLANT CELL
Copyright © 1999 by the American Society of Plant Biologists