Synergistic application of taurine and spermidine enhances wheat tolerance to neodymium stress through redox homeostasis, metabolic adjustment, and nutrient regulation

ratio and macronutrient acquisition and improved the grain yield, protein, starch, and micronutrient density. Pearson correlation, radar, and principal component analyses confirmed coordinated recovery across soil, physiological, and grain-quality traits. These findings demonstrate that taurine and spermidine act synergistically to enhance wheat tolerance to Nd toxicity through the modulation of antioxidant defenses, osmotic adjustment, nutrient homeostasis, and metal exclusion mechanisms, highlighting their potential as sustainable biostimulants for crop production in rare-earth-element-contaminated soils.