Elucidating the impact of titanium dioxide nanopriming on germination and growth of Zea mays under salinity stress

Soil salinization is a major constraint to agricultural productivity, particularly in arid and semi-arid regions such as Haryana, India. This study evaluated green-synthesized anatase-phase titanium dioxide nanoparticles (TiO2 NPs) as a seed nanopriming agent to improve salinity tolerance in maize (Zea mays L.). TiO2 NPs were characterized by FTIR, XRD, FESEM, EDX, HRTEM and Malvern Zetasizer analyses. Seeds primed with 20, 40 and 60 ppm TiO2 NPs were exposed to 0, 50 and 100 mM NaCl. Salinity reduced germination, seedling growth, water uptake, photosynthetic pigments and membrane stability while increasing oxidative stress. Nanopriming with 40 ppm TiO2 NPs significantly enhanced germination, seedling vigor, shoot and root growth, photosynthetic pigments, antioxidant enzyme activities, osmotic adjustment and membrane integrity compared with unprimed salt-stressed plants. AAS confirmed Ti accumulation in seed, root and shoot tissues, indicating nanoparticle uptake and translocation. Overall, 40 ppm TiO2 nanopriming effectively improved maize tolerance to salinity stress.