Document Type : Research Paper
Authors
Department of Genetics and Plant Breeding, Faculty of Agriculture and Natural Resources, Imam Khomeini International University, Qazvin, Iran
Abstract
Introduction
Japanese barberry (Berberis thunbergii) is a perennial and woody shrub that grows in different regions of Iran and the world. The Berberidaceae family has a high potential in food and pharmaceutical industries due to its antioxidant, antimicrobial and anticancer activities. Elicitors are biotic or abiotic stimulators can induce responses in plants. Abiotic elicitors are used to increase secondary metabolites in plants. Nanoparticles have minimum dimensions between one and 100 nanometers, which have specific physical and chemical properties. Like many nanoparticles, zinc oxide and cerium dioxide nanoparticles are toxic to living organisms. The mechanism of toxicity of nanoparticles is generally caused by the induction of oxidative stress caused by the formation of free radicals. Nanoparticles of zinc oxide and cerium dioxide can increase the antioxidant capacity of plants by stimulating oxidative stress.
Material and methods
In order to study the changes in the physiological and biochemical characteristics of Japanese barberry under the influence of abiotic elicitors, an experiment was conducted in the form of a completely randomized design in the greenhouse and laboratory of the Faculty of Agriculture and Natural Resources of Imam Khomeini International University in 2019. Treatments including zinc oxide elicitors (0.1 g/L) and cerium dioxide nanoparticles (0.0002 g/L) and control (no elicitor) were investigated in three replicates. In this research, the amounts of protein, antioxidant enzymes and photosynthetic pigments in tissues of Japanese barberry were extracted and measured. Data analysis was done with SAS 9.1.3 statistical software. Comparison of means was done with Duncan's multiple range test and graphs were drawn using Excel software.
Results and Discussion
The results of the data analysis of variance showed that the effect of treatment with cerium dioxide and zinc oxide nanoparticle elicitors on the amount of leaf protein, antioxidant activity and also the amount of photosynthetic pigments was significant. Comparison of the means showed that these two elicitors increased the leaf protein content by 26.2% and 12.4%, respectively, compared to the control, but they did not have a significant effect on the root protein content. Cerium dioxide decreased the activity of guaiacol peroxidase enzyme by 77.1% in the root; But in leaves, the activity of this enzyme increased by 134.8% due to treatment with zinc oxide. The highest activity of leaf superoxide dismutase enzyme (25.2% increase compared to control) was related to zinc oxide treatment. The lowest content of catalase enzyme in leaves and roots was obtained with cerium dioxide and zinc oxide. Zinc oxide increased the activity of leaf ascorbate peroxidase enzyme by 111.8%; In the root, the highest and lowest activity levels of this enzyme were obtained from the control and cerium dioxide treatments, respectively. Both elicitors significantly increased the leaf peroxidase enzyme activity compared to the control (128.6% and 157.1%, respectively); However, only the treatment with zinc oxide caused a significant increase of 25.5% in the activity of this enzyme in the root. The highest activity of glutathione reductase enzyme in leaf and root was observed in zinc oxide treatment (23.3% and 12.5% increase compared to control). Nano zinc oxide increased the amount of total chlorophyll and carotenoid in the leaves compared to the control by 93.4 and 67.5%, respectively.
Conclusion
It was concluded that zinc oxide nanoparticles elicitor had the greatest effect in increasing the amount of photosynthetic pigments and enzyme activity. By using this elicitor in Japanese barberry culture, the amount of antioxidant enzymes can be increased and the extract can be used as a strong antioxidant in pharmaceutical products.
Keywords
Main Subjects
)