Positive effects of cerium oxide nanoparticles on growth and biochemical parameters of Moldavian balm under salinity stress

Salinity is one of the most common abiotic stresses with negative impacts on soils and plants. Substantial disorders in morphologic and physiologic characterizations of plants including decrease in shoots and leaves growth, photosynthetic pigments and membrane permeability could be an important salinity effect. Over recent years, application of engineered nanoparticles (NPs) has been increased to lessen the impacts of salinity stress in modern agriculture. The current study aimed to evaluate the effects of synthesized cerium oxide NPs (CeO۲ NPs) (at ۲۵, ۵۰ and ۱۰۰ mg L-۱ concentrations) under salinity stress conditions (۵۰ and ۱۰۰ mM NaCl) on Moldavian balm (Dracocephalum moldavica L.). A complexly randomized design (CRD) was used with three replications. Salinity stress was daily imposed until the harvest, three weeks later to imposing salinity, four levels of CeO۲ NPs (۸-۱۵ nm) were applied through foliar spraying over aerial parts, then, physiological and morphological traits were measured. Salinity decreased agronomic traits such as leaves and shoots fresh and dry weights, chl a, b and carotenoid and SPAD and increased MDA, H۲O۲, EL, Pro, antioxidant enzyme activities (SOD, APX and GP). Besides positive effect of CeO۲ NPs under non-stress condition, CeO۲ NPs application decreased the negative impacts of salinity through significant increase in agronomic traits, photosynthetic pigments, SPAD, Pro, antioxidant enzymes. In addition, CeO۲ NPs decreased MDA, H۲O۲ and EL under salinity condition. ۵۰ mg L-۱ concentration of CeO۲ NPs could be considered as the best treatment under both non-stress and salt-stress conditions. In conclusion, CeO۲ NPs treatments on Moldavian balm improved the plant performance under salinity and could be considered as a promising treatment to alleviate salt stress condition.

کلیدواژه ها:

Lamiaceae ، abiotic stress ، nanotechnology ، secondary metabolite