Mathematical modelling of diurnal regulation of carbohydrate allocation by osmo-related processes in plants

Alexandra Pokhilko, Oliver Ebenhöh

Research output: Contribution to journalArticle

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Abstract

Plants synthesize sucrose in source tissues (mainly mature leafs) and supply it for growth of sink tissues (young leafs). Sucrose is derived from photosynthesis during daytime and from starch at night. Because the diurnal regulation of sucrose fluxes is not completely understood, we built a mathematical model designed to reproduce all key experimental observations. For this, assumptions were made about the molecular mechanisms underlying the regulations, which are all motivated by experimental facts. The key regulators in our model are two kinases (SnRK1 and osmo-sensitive kinase OsmK) under the control of the circadian clock. SnRK1 is activated in the night to prepare for regularly occurring carbon-limiting conditions, whereas OsmK is activated during the day to prepare for water deficit, which often occurs in the afternoon. Decrease of SnRK1 and increase of OsmK result in partitioning of carbon towards sucrose to supply growing sink tissues. Concomitantly, increasing levels of the growth regulator trehalose-6-phosphate stimulates the development of new sink tissues and thus sink demand, which further activates sucrose supply in a positive feedback loop. We propose that OsmK acts as a timer to measure the length of the photoperiod and suggest experiments how this hypothesis can be validated.

Original languageEnglish
Article number20141357
Number of pages11
JournalJournal of the Royal Society Interface
Volume12
Issue number104
Early online date6 Mar 2015
DOIs
Publication statusPublished - Mar 2015

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Sugar (sucrose)
Carbohydrates
Sucrose
Tissue
Phosphotransferases
Carbon
Circadian Clocks
Photosynthesis
Photoperiod
Growth
Starch
Clocks
Phosphates
Theoretical Models
Mathematical models
Fluxes
Feedback
Water
Experiments

Keywords

  • mathematical modelling
  • carbohydrate metabolism
  • plant physiology
  • circadian clock
  • systems biology

Cite this

Mathematical modelling of diurnal regulation of carbohydrate allocation by osmo-related processes in plants. / Pokhilko, Alexandra; Ebenhöh, Oliver.

In: Journal of the Royal Society Interface, Vol. 12, No. 104, 20141357, 03.2015.

Research output: Contribution to journalArticle

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