Impact of ZnO NPs, Pi Availability and the Interaction of Pi x NaCl in Reducing the Negative Effect of Salinity and Pi Deficiency on Growth of Arabidopsis Plant

Most crop production is decreased by salinity in agriculture, which is one of the main abiotic stressors that lowers crop production. One of the detrimental effects of salinity on plant growth and productivity is known as nutritional imbalance such as phosphate (Pi). Approximately 54% of the cultivated area of Saudi Arabia suffers from salinization. While its soils characterized by low available Pi. Such regions in Saudi Arabia, the factors of soil salinity and Pi deficiency pose major challenge to agricultural production. Nowadays, zinc oxide nanoparticles (ZnO NPs) are widely used in agriculture, and many investigations were carried out to determine the impact of ZnO NPs on plants under abiotic stress. So far, few research investigated into the potential impact of ZnO NPs on the growth of Arabidopsis plants under salt and Pi deficiency, and their interaction. This study aimed to investigate the effect of ZnO NPs application (10 mg/L), Pi availability and the interaction of Pi x NaCl in reducing the negative effect of the salinity and Pi deficiency on growth of Arabidopsis. Arabidopsis plants were grown hydroponically under different treatments of Pi and NaCl, and the interaction of Pi x NaCl with/without ZnO NPs and ZnO BPs. The results indicated that salinized plants had a reduction in plant growth traits, but, the values of these traits increased with high Pi (100 and 250 μM). Pi at 10 µM is more detrimental than NaCl at 100 mM for plant growth. Salt-treated plants (50, 100 mM) exposed to high Pi (100 and 250 μM) showed higher salt tolerance. In contrast, plants subjected to NaCl (150 mM) and Pi (250 μM) exhibited reduce in the values of growth parameter. Results also showed that ZnO NPs and ZnO BPs was sufficient to protect plant against salinity and Pi deficiency, however ZnO NPs was more efficient than ZnO BPs. The Pi availability, the combined treatment of Pi x NaCl, and ZnO NPs can be a promising application to alleviate the negative impacts of salinity and Pi deficiency on plant growth.