Integrating remote sensing and metabolomics to assess synergistic effects of phosphate deficiency, drought, and AMF symbiosis in soybean

Authors: HASSAN, MUHAMMAD - Oak Ridge Institute For Science And Education (ORISE); KIBBE, RUSSELL - North Carolina State University; MUDDIMAN, DAVID - North Carolina State University; Chang, Christine

Submitted to: Physiologia Plantarum
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/26/2025
Publication Date: 1/19/2026
Citation: Hassan, M.A., Kibbe, R., Muddiman, D.C., Chang, C.Y. 2026. Integrating remote sensing and metabolomics to assess synergistic effects of phosphate deficiency, drought, and AMF symbiosis in soybean. Physiologia Plantarum. https://doi.org/10.1111/ppl.70679.
DOI: https://doi.org/10.1111/ppl.70679

Interpretive Summary: Drought has been one of the leading causes of global soybean yield loss during the last half century. Biofertilizers such as symbiotic fungi enhance plant-soil interactions and can improve soybean drought resilience, but their effectiveness varies in different soil environments and among cultivars. Interactions among two soybean cultivars differing in fungal biofertilizer association, soil phosphate availability, and their impact on drought resilience were evaluated using root fungal colonization, photosynthesis, metabolites and remote sensing. Soybean plants grown under phosphate deficiency had reduced growth but increased interactions with fungal biofertilizers and showed improved drought resilience, with one cultivar outperforming the other. The findings provide useful insights on soil conditions for growers looking to improve biofertilizer effectiveness, and identifies drought-responsive vegetation indices and metabolite markers that may be useful for soybean breeders seeking to enhance crop drought resilience.

Technical Abstract: Soybean is highly sensitive to abiotic stresses such as phosphate (P) deficiency and drought, which significantly constrain growth and yield. Symbiotic association of plant roots with arbuscular mycorrhizal fungi (AMF) can enhance nutrient acquisition and improve water uptake, thereby increasing plant resilience under stress conditions. This study integrates physiological, remote sensing, and metabolomic analyses to investigate the interactive effects of P availability and drought on AMF symbiosis in two soybean genotypes. Under P deficiency (P-), AMF colonization significantly (P<0.05) increased, enhancing root hair development and maintaining lower leaf water potential (') in drought stress especially in S-81 cultivar. However, drought was the dominant factor driving declines in photosynthetic activity, and metabolite accumulation compared to P treatment. A significant (p < 0.05) decline in all physiological and remotely sensed vegetation indices (VIs) was observed under drought in both P treatments. However, P sufficient (P+) plants showed overall high biomass at harvest. Among VIs, CIgreen and CIrededge710 and PRI were more responsive to P treatment during drought than NDVI and PSRI. A significant reduction in blue light-induced chlorophyll fluorescence R:FR ratio was also observed under drought. Several metabolites involved in carbohydrate metabolism, jasmonic acid biosynthesis, and amino acid metabolism exhibited significant variations among genotypes and P treatment under drought stress. Interestingly, a metabolite involved in vitamin K1 biosynthesis (C11H12O6) also showed significant upregulation under drought in P- plants with a strong correlation (r = 0.72) to '. These findings highlight the critical role of P availability in increasing the AMF symbiosis and drought resistance under water stress and demonstrate the value of high-throughput phenotyping for advancing stress resilient research in soybean.