Xibei zhiwu xuebao (Nov 2024)
Effects of zinc oxide nanoparticles pretreatment on physiological response of Lycium barbarum seedlings under salt and alkali stress
Abstract
[Objective] The study aims to investigate the effects of zinc oxide nanoparticles (ZnO NPs) on wolfberry seedlings under saline-alkali stress, evaluate its physiological mechanism for alleviating saline-alkali stress, and explore its application potential and suitable concentrations. [Methods] One-year-old ‘Ningqi No. 10’ wolfberry seedlings in pots were used as materials. The roots were irrigated with ZnO NPs solutions of different concentrations (50, 100, and 150 mg/L), followed by 100 mmol/L saline-alkali stress treatment. Samples were collected after 15 and 30 days of stress treatments to measure seedling biomass, photosynthetic pigments, osmoregulatory substances, Na+ , K+ , and reactive oxygen species (ROS) content, antioxidant enzyme activity, and AsA-GSH cycle-related indicators. A comprehensive evaluation of the treatments was conducted. [Results] ZnO NPs pretreatment significantly promoted the accumulation of biomass in wolfberry seedlings under saline-alkali stress, increased leaf chlorophyll content, enhanced the content of antioxidant substances and related enzyme activities in the AsA-GSH cycle, as well as SOD, POD, and CAT activities. It significantly reduced cell membrane damage and lipid peroxidation, significantly increased the accumulation of soluble sugar, proline, and soluble protein, and regulated the Na+/K+ balance. Among the tested concentrations, 100 mg/L ZnO NPs treatment showed the best mitigation effect. [Conclusion] Root application of ZnO NPs effectively alleviates the growth inhibition of wolfberry seedlings under saline-alkali stress by promoting chlorophyll accumulation, regulating the AsAGSH cycle and antioxidant enzyme activity to efficiently scavenge excessive ROS, enhancing osmotic adjustment capacity, and maintaining Na+/K+ balance.
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