Plant Physiol. email content delivery
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
QUICK SEARCH:   [advanced]


     

Plant Physiology Preview
Published on May 12, 2006; 10.1104/pp.106.081174

This Article
Right arrow Full Text (Plant Physiology Preview (PDF))
Right arrow All Versions of this Article:
141/3/879    most recent
pp.106.081174v1
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 (9)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Weise, S. E.
Right arrow Articles by Sharkey, T. D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Weise, S. E.
Right arrow Articles by Sharkey, T. D.
Agricola
Right arrow Articles by Weise, S. E.
Right arrow Articles by Sharkey, T. D.

Received March 29, 2006
Returned for revision April 17, 2006
Accepted May 7, 2006

Carbon balance and circadian regulation of hydrolytic and phosphorolytic breakdown of transitory starch

Sean E. Weise , Stephen M. Schrader , Kyle R. Kleinbeck , and Thomas D. Sharkey *

University of Wisconsin-Madison, Department of Botany, 430 Lincoln Dr., Madison, WI 53726, USA

* Corresponding author; email: tsharkey{at}wisc.edu.

Transitory starch is formed in chloroplasts during the day and broken down at night. Transitory starch degradation could be regulated by light, circadian rhythms, or by carbon balance. To test the role of these potential regulators, starch breakdown rates and metabolites were measured in bean (Phaseolus vulgaris) and Arabidopsis thaliana plants. In continuous light, starch and maltose levels oscillated in a circadian manner. Under photorespiratory conditions transitory starch breakdown occurred in the light faster than at night and glucose 6-phosphate (G6P) was elevated. Nonaqueous fractionation showed that the increase in G6P occurred in the chloroplast. When Arabidopsis plants lacking the plastidic starch phosphorylase enzyme were placed under photorespiratory conditions, G6P levels remained constant indicating that the increased chloroplastic G6P resulted from phosphorolytic starch degradation. Maltose was increased under photorespiratory conditions in both wild type and plants lacking starch phosphorylase, indicating that regulation of starch breakdown may occur at a point preceding the division of the hydrolytic and phosphorolytic pathways. When bean leaves were held in N2 to suppress photosynthesis and sucrose synthesis without increasing photorespiration, starch breakdown did not occur and maltose and G6P levels remained constant. The redox status of the chloroplasts was found to be oxidized under conditions favoring starch degradation.




This article has been cited by other articles:


Home page
 J Exp BotHome page
A. M. Borland, H. Griffiths, J. Hartwell, and J. A. C. Smith
Exploiting the potential of plants with crassulacean acid metabolism for bioenergy production on marginal lands
J. Exp. Bot., July 1, 2009; 60(10): 2879 - 2896.
[Abstract] [Full Text] [PDF]

Home page
 Plant CellHome page
D. C. Fulton, M. Stettler, T. Mettler, C. K. Vaughan, J. Li, P. Francisco, M. Gil, H. Reinhold, S. Eicke, G. Messerli, et al.
{beta}-AMYLASE4, a Noncatalytic Protein Required for Starch Breakdown, Acts Upstream of Three Active {beta}-Amylases in Arabidopsis Chloroplasts
PLANT CELL, April 1, 2008; 20(4): 1040 - 1058.
[Abstract] [Full Text] [PDF]

Home page
 Proc. Natl. Acad. Sci. USAHome page
S. Aluri and M. Buttner
Identification and functional expression of the Arabidopsis thaliana vacuolar glucose transporter 1 and its role in seed germination and flowering
PNAS, February 13, 2007; 104(7): 2537 - 2542.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
ASPB Publications PLANT PHYSIOLOGY® THE PLANT CELL
Copyright © 2006 by the American Society of Plant Biologists