Leaf to root : soybean nodule traits monitored non

Graphic representation of the research hypothesis on the correlation between leaf spectral signatures and the underlying nodule traits (number and total weight) under abiotic stresses (salt and drought). Soybean (Glycine max) forms symbiotic root nodules with nitrogen-fixing rhizobia, converting atmospheric nitrogen into ammonia and reducing reliance on synthetic fertilizers. Nodule number and weight are key indicators of symbiotic efficiency and yield potential, yet current quantification relies on excavating roots, excising nodules, and weighing them manually. These methods are destructive, labor-intensive, and poorly suited to longitudinal monitoring or high-throughput phenotyping. Drought, salinity, and rhizobium strain identity can strongly alter nodulation, creating complex trait variation that is difficult to track over time. Based on these challenges, in-depth research is needed to develop non-destructive, scalable tools linking aboveground leaf signals to belowground nodule traits. In a study published (DOI: 10. 1016/j. plaph. 2026.