Abstract
<jats:p> Plants acclimate to low temperature by remodeling carbohydrate metabolism. Permanent cold at 4/5 °C induces well-characterized cold acclimation in plants, including accumulation of starch and soluble sugars. In natural environments, however, annual plants in their vegetative phase more frequently experience chilling nights (0-6 °C nights followed by days at least 12 °C warmer), whose metabolic consequences remain poorly understood. We investigated Col-0 <jats:italic>Arabidopsis thaliana</jats:italic> exposed to one or seven chilling nights and quantified central carbohydrate metabolites, starch, photosynthetic parameters, and maximal activities of enzymes linking sucrose synthesis and cleavage. We integrated these time-series data into a biologically constrained augmented neural ordinary differential equation (ANODE) model to infer diurnal reaction-rate dynamics. Chilling nights induced strong accumulation of sucrose, glucose, and fructose, particularly after seven nights. Both measured sucrose phosphate synthase (SPS) capacity and ANODE-predicted SPS rates increased. In contrast to permanent cold acclimation, daytime starch over-accumulation was absent. Thus, lacking starch over-accumulation together with increased SPS rates, chilling nights invoke distinct carbohydrate‑partitioning patterns towards sucrose, indicating a fundamentally different acclimation strategy compared to well described permanent cold. </jats:p>