Foliar Spray of Biosynthesized Zinc Oxide Nanoparticles Alleviate Salinity Stress Effect on Vicia faba Plants

Abstract Previous studies recorded positive impact of ZnO NPs on plants stressed with salinity. The current work was performed to study the effect two different concentrations biosynthesized (50 and 100 mg L ?1 ) faba bean under salinity stress. zinc oxide nanoparticles (ZnO NPs) were synthesized using Mentha extract, their shape size characterized X-ray diffraction transmission electron microscope while diffuse reflectance spectra measured UV–Vis spectrophotometer. generated spherical a particle 9.4 nm had rod form 15.2 in length 3.5 width. response been foliar spray (0, 50, alone combination salt stress at 150 mM NaCl studied. Salinity induced reduction root shoot dry/fresh weights, an enhancement treatment 50 either presence or absence highest amounts chlorophyll a, b, carotenoids, total pigments received compared alternative control. Secondary metabolites (phenols, flavonoids, tannins) accumulated salinity-stressed further accumulation noticed. Amino acids, proline, glycine betaine, soluble sugars, as well enzymatic non-enzymatic antioxidant contents, increased almost onefold control resulted higher previously mentioned substances. In contrast, oxidative reduced treatments. nitrogen, phosphorus, potassium, calcium, zinc, iron contents applied NPs. Faba MN showed growth decline that may be attributed osmotic low water availability imposed by plant antioxidants, osmolytes, secondary could help overcome negative effects