Foliar application of graphene oxide, nano-Fe, and selenium mitigates salinity depression on Ocimum basilicum

: An experiment was conducted to investigate the effects of salinity stress and foliar applications of graphene oxide, nano-Fe, and selenium on basil’s growth and physiological responses. The results revealed that the treatments affected plant dry weight, essential oil, and malondialdehyde content, relative water content as well as hydrogen peroxide, proline, sodium, iron, and phosphorus content, and sodium to potassium ratio. The highest plant dry weight and essential oil content were recorded under no-salinity and 50 mM salinity × iron nanoparticle foliar use, while 100 mM salinity stress with no foliar spraying increased the levels of malondialdehyde, sodium content, and sodium-to-potassium ratio. The experimental treatments independently affected catalase activity and chlorophyll, calcium, nitrogen, potassium, manganese, zinc, and magnesium content. Foliar treatment of nanoparticles improved chlorophyll b, potassium, manganese and nitrogen content, and catalase activity. Under the control conditions and 50 mM salinity, the magnesium, calcium, and chlorophyll contents were enhanced. Graphene oxide and selenium foliar applications enhanced the calcium and magnesium content of plants. The foliar treatments were partially effective in mitigating the salinity defects under mild-stress conditions. Otherwise, with exposure to the salinity of 100 mM, the foliar treatments could not control the adverse effects of salt stress on the plant.