Carbon sink–source dynamics influence bud awakening under warming and defoliation

Plant metabolism largely depends on carbohydrates.Non-structural carbohydrates (NSCs; i.e., those not constituting biomass) are a key energy source and serve as the initial components of many structural and metabolic compounds, as well as they regulate cell osmotic potential (Hartmann & Trumbore 2016).The most basic NSCs are isomers glucose and fructose, which are synthesized during photosynthesis and either directly consumed or transformed into different metabolites, including structural compounds such as cellulose and reserve compounds such as sucrose or starch, as well as lipids and proteins.Soluble sugars are transported across the plant through the phloem, mainly in the form of sucrose, to be subsequently used in cell metabolism or stored as starch.In addition to sugars, polyols (i.e., chemically reduced sugars or sugar alcohols), such as d-pinitol, play an important role in plant carbon transport and