Bridging Photosynthesis and Crop Yield Formation with a Mechanistic Model of Whole Plant Carbon-Nitrogen Interaction

Abstract Crop yield is determined by potential harvest organ size, source photosynthesis and carbohydrate partitioning. Filling the efficiently remains a challenge. Here, we developed kinetic model of rice grain filling, which scales from primary biochemical biophysical processes to whole-plant carbon nitrogen dynamics. The reproduces formation process under different environmental genetic perturbations. In silico screening identified range post-anthesis targets—both established novel—that can be manipulated enhance yield. Remarkably, pinpointed stability grain-filling rate flowering as critical factor for maximizing This finding was further validated in two independent super-high-yielding cultivars, each yielding approximately 21 t ha−1 rough at 14% moisture content. Furthermore, revealed that stabilizing could lead increase 30–40% an elite cultivar. Notably, instantaneous rates around 15- 38-day post-flowering significantly influence yield; introduced innovative situ approach using ear respiratory precise quantification these rates. We finally derived equation predict maximum dried brown (Y, ha−1) cultivar based on its gross photosynthetic accumulation (Apc, CO2 ha−1): Y = 0.74 × Apc + 1.9. Overall, this work establishes framework quantitatively dissecting crop physiology designing high-yielding ideotypes.