Soluble sugar and starch, the two components of non-structural carbohydrates (NSC), play distinct roles in ensuring physiological stabilities in plants. However, it is far from clear whether they will respond symmetrically or asymmetrically to future environmental change.
Results/Conclusions
Here, based on a comprehensive meta-analysis of 260 experiments, we show that soluble sugar and starch respond unevenly to multiple environmental changes. Elevated atmospheric CO2 concentration significantly enhanced starch storage by 71.2%, which was about six folds of sugars (+12.9%). Both experimental warming (-18.8%) and drought (-21.8%) decreased starch storage, whereas sugars storage was unchanged and increased (+11.08%) under warming and drought, respectively. Nitrogen addition significantly reduced the storage of sugars (-10.0%) but not starch. Such asymmetric responses between soluble sugar and starch to environmental changes were independent on either plant functional type or organs. In addition, the magnitude of asymmetry increased with the duration of treatment under the changes of all environmental factors. These results suggest a composition shift of NSC in plants under future global environmental changes, and we recommend photosynthesis models to consider the different activities and functions of sugars and starch instead of representing NSC as the single storage pool.