Foliar Application of ZnO-NPs Influences Chlorophyll Fluorescence and Antioxidants Pool in Capsicum annum L. under Salinity

Zinc oxide nanoparticles (ZnO-NPs) have been proven to helpfully improve plant tolerance several abiotic stresses. However, no information has reported concerning the role of ZnO-NPs on pepper plants under salinity stress. Hence, this research aimed evaluate growth and physiological responses (Capsicum annum L.) ZnO-NP foliar application salinity. Plants were subjected 0 (control), 25 (S1), 50 (S2), 75 mM (S3) NaCl with a spray 0, 1000, 2000 ppm ZnO-NPs. Significant reductions recorded in chlorophyll index (SPAD) fluorescence parameters, activity and/or ratios reduced ascorbate (AsA), ascorbate/dehydroascorbic acid (AsA/DHA), glutathione (GSH), glutathione/oxidized (GSH/GSSG), K+ content. There was significant increase proline content, electrolyte leakage (EL), H2O2 guaiacol peroxidase (GPX), (APX), superoxide dismutase (SOD), reductase (GR), dehydroascorbic (DHA), oxidized (GSSG) activities, Na+ content Na+/K+ ratio. Foliar treatments improved by fortifying antioxidant defense system, leaf K+, contrast, decreasing EL, Na+, levels. treatment efficiently plants’ Considering overall results, 1000 would be advisable for amelioration depression promote potential. at higher levels, nanoparticle showed toxicity symptoms that limited its reliable applications.