Dynamical feedback between circadian clock and carbohydrate availability explains adaptive response of starch metabolism to longer night

Abstract

We study the regulation of sucrose level by shifting the internal circadian related rates of sucrose export, and synthesis and degradation of starch in a leaf. We allow these shifts to change dynamically in order to reduce sucrose starvation in several light/dark cycle conditions. The model successfully reduces starvation in the leaf and show many features similar to observations. Finally we include the leaf model in a phloem network containing a root and a meristem, the three of them connected and exchanging sucrose by osmotic pressure driven flow. The global model allows sucrose sharing among organs and an overall lower starvation level.