Regulatory principles and experimental approaches to the circadian control of starch turnover

Daniel D Seaton, Oliver Ebenhoeh, Andrew J Millar, Alexandra Pokhilko*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

21 Citations (Scopus)
5 Downloads (Pure)

Abstract

In many plants, starch is synthesized during the day and degraded during the night to avoid carbohydrate starvation in darkness. The circadian clock participates in a dynamic adjustment of starch turnover to changing environmental condition through unknown mechanisms. We used mathematical modelling to explore the possible scenarios for the control of starch turnover by the molecular components of the plant circadian clock. Several classes of plausible models were capable of describing the starch dynamics observed in a range of clockmutant plants and light conditions, including discriminating circadian protocols. Three example models of these classes are studied in detail, differing in several important ways. First, the clock components directly responsible for regulating starch degradation are different in each model. Second, the intermediate species in the pathway may play either an activating or inhibiting role on starch degradation. Third, the system may include a light-dependent interaction between the clock and downstream processes. Finally, the clock may be involved in the regulation of starch synthesis. We discuss the differences among the models' predictions for diel starch profiles and the properties of the circadian regulators. These suggest additional experiments to elucidate the pathway structure, avoid confounding results and identify the molecular components involved.

Original languageEnglish
Article number20130979
Number of pages12
JournalJournal of the Royal Society Interface
Volume11
Issue number91
Early online date11 Dec 2013
DOIs
Publication statusPublished - 6 Feb 2014

Keywords

  • starch metabolism
  • circadian rhythms
  • arabidopsis thaliana
  • mathematical modelling
  • systems biology
  • biological clocks
  • ADP-glucose pyrophosphorylase
  • pseudo-response regulators
  • arabidopsis-thaliana
  • numerical-simulation
  • diurnal changes
  • metabolism
  • growth
  • clock
  • degradation
  • leaves

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