Prominent Effects of Zinc Oxide Nanoparticles on Roots of Rice (Oryza sativa L.) Grown under Salinity Stress

The morphological plasticity of plant roots is a key factor in their ability to tolerate a wide range of edaphic stresses. There are many unanswered questions relating to nanotechnology and its potential uses for sustainable agriculture. The main purpose of this study was to examine the effects of salinity-induced morphogenic responses and zinc oxide nanoparticles (ZnO-NPs) on root characteristics, growth, MDA content, antioxidant enzymatic activity, and root ion accumulation in rice (Oryza sativa L.). The experiment was conducted in a hydroponic culture containing 50 mg/L of ZnO-NPs and different concentrations (60, 80, and 100 mM) of NaCl for 14 days. The results indicated a decrease in rice root growth due to exposure to salinity (length, fresh, and root dry weight). The results showed that salinity caused a reduction in rice root growth (length, fresh, and root dry weight). Higher root sodium (Na+) accumulation, MDA content, and potassium level decreased with increasing salinity. Root length, root fresh weight, root dry weight, root K+ content, and root antioxidant enzymatic activity were all enhanced by applying 50 mg/L ZnO-NPs often in salinity. SEM analysis revealed that ZnO-NPs treatments significantly improved root morphology. There was a notable decrease in root Na+ content as a result, which improved the K+/Na+ ratio in the rice’s root system. These findings suggest that O. sativa, when treated with ZnO-NPs, can thrive under salt-stress conditions, opening up the possibility of cultivating the plant in extreme climates.