Mohammad Shahid, Sajad Ali
ABSTRACT This study reported the synergistic role of zinc oxide nanoparticles (ZnO‐NPs; 100 mg L −1 ) and salicylic acid (SA; 0.2 mM) in mitigating the adverse effects of salinity (NaCl) stress in greengram. The combined (ZnO‐NPs + SA) treatment improves diverse morphological, physiological, and biochemical traits in greengram during salt stress. For instance, ZnO‐NPs + SA treatment increased root biomass (40.6%), chlorophyll a (25%), and carotenoid contents (31.5%) under 50 mM NaCl stress. ZnO‐NPs + SA also showed a remarkable reduction in hydrogen peroxide (67.7%) and lipid peroxidation (68.7%), indicating improved redox stability. Notably, the combined treatment restored ion homeostasis by reducing Na + accumulation in roots and shoots by 76.3% and 69.7%, and enhancing K + levels by 56.2% and 54%, in greengram at 50 mM NaCl concentration. Additionally, ZnO‐NPs + SA treatment improved the antioxidant defense responses in salt‐stressed greengram, as seen by the increased accumulation of enzymes such as CAT, APX, GPOX, SOD, and GR and their expression. The combined treatment further boosted the non‐enzymatic antioxidants, including PAL, TAL activity, total phenol, flavonoids, DPPH and FRAP in salinity‐stressed greengram plants. The synergistic nanoparticle–phytohormone interaction improved the yield attributes of salinity‐stressed greengram, underscoring its agronomic value. Overall, the current study reveals a novel, integrated physiological–molecular mechanism by which ZnO‐NPs and SA jointly enhance salinity tolerance, offering a promising strategy for cultivating greengram and other legumes in salt‐affected soils. These findings provide a practical, scalable bio‐stimulant strategy for improving legume productivity in salinity‐affected agricultural systems.