The effect of biosynthesized silver nanoparticles on some physiological and biochemical parameters of viola tricolor (Viola tricolor L.)

Employing biosynthesized nanoparticles plays an important role in increasing efficiency of agricultural practices. In recent years, the use of nanoparticles in plants has been considered as pesticides, protective agents, and nutrients. Viola tricolor belongs to the Violaceae family, which has antibacterial, anticancer, and antiviral properties. In this study, silver nanoparticles were synthesized using silver nitrate and Viola tricolor extract to investigate the effect of different concentrations of silver nanoparticles on the physiologic and biochemical indexes of Viola tricolor. Results showed that different growth parameters including root and stem fresh weight, root and shoot length, and protein content significantly increased under AgNPs. The highest levels of these indices were observed at 0, 10, 50 and 100 ppm silver nanoparticles, respectively. Proline and carbohydrates also increased under different concentrations of AgNPs compared with the control and the highest values of these indices were observed under 100 ppm silver nanoparticles. The contents of secondary metabolites, including phenol and flavonoids, were affected under 100 ppm AgNP showing the highest increase. The maximum increase in the anthocyanin content was observed at 10 ppm AgNPs. Analysis of the antioxidant enzyme activities showed that they increased under all AgNPs concentrations of the study. Increases in the activities of antioxidant enzymes (catalase and glutathione reductase) under AgNPs treatments led to a decrease in MDA content. Based on the results of the current study, silver nanoparticles are suggested as proper stimulants for increased growth and production of antioxidant properties.