Foliar Application of Cerium Oxide-Salicylic Acid Nanoparticles (CeO2:SA Nanoparticles) Influences the Growth and Physiological Responses of Portulaca oleracea L. under Salinity.

Abstract

In the present study, the effects of foliar application of salicylic acid (100 μM), cerium oxide (50 mg L−1), and cerium oxide:salicylic acid nanoparticles (CeO2: SA-nanoparticles, 50 mg L−1 + 100 μM) on the growth and physiological responses of purslane (Portulaca oleracea L.) were examined in non-saline and saline conditions (50 and 100 mM NaCl salinity). Foliar applications mitigated salinity-induced adverse effects, and the highest plant height and N, P, Mg, and Mn content were recorded in the variant with non-saline × foliar use of CeO2: SA-nanoparticles. The highest values of fresh and dry weight were noted in the treatment with no-salinity × foliar use of CeO2:SA-nanoparticles. The highest number of sub-branches was observed in the foliar treatments with CeO2-nanoparticles and CeO2:SA-nanoparticles without salinity stress, while the lowest number was noted in the 100 mM NaCl treatment. Moreover, the foliar application of CeO2:SA-nanoparticles and cerium-oxide nanoparticles improved the total soluble solid content, K, Fe, Zn, Ca, chlorophyll a, and oil yield in the plants. The salinity of 0 and 50 mM increased the K content, 1000-seed weight, total soluble solid content, and chlorophyll b content. The use of 100 mM NaCl with no-foliar spray increased the malondialdehyde, Na, and H2O2 content and the Na+/K+ ratio. No-salinity and 50 mM NaCl × CeO2: SA-nanoparticle interactions improved the anthocyanin content in plants. The phenolic content was influenced by NaCl100 and the foliar use of CeO2:SA-nanoparticles. The study revealed that the foliar treatment with CeO2:SA-nanoparticles alleviated the side effects of salinity by improving the physiological responses and growth-related traits of purslane plants.