The effects of zinc oxide nanoparticles on sterilization, establishment, and proliferation of lemon balm (Melissa officinalis L.)

Plant tissue culture is one of the most important techniques for the production of secondary metabolites. Plant cells are an important and appropriate source for the production of various valuable secondary metabolites. Melissa officinalis L. is an important medicinal plant with applications in treatment and alleviation of heart, nervous system, and gastrointestinal diseases, and particularly in memory enhancement and Alzheimer. This study investigated the effect of various concentrations of zinc oxide nanoparticles (0, 50, 100, 150, and 200 mg l-1) on disinfection stages, establishment, and proliferation of the lemon balm. Also, in order to study the effects of zinc oxide nanoparticles on establishment and proliferation of the lemon balm, explants were cultivated in murashige and skoog media containing zinc oxide nanoparticles at four different concentrations (0, 25, 50 and 75 mg L-1). Results showed that application of 200 mg l-1 zinc oxide nanoparticles significantly reduced fungal and bacterial infections and the number of healthy plantlets was more compared to the other treatments. Also, the second experiment showed that with an increase in the concentration of zinc oxide nanoparticles, the growth and proliferation decreased. Among different concentrations of zinc oxide nanoparticles, 25 mg L-1 had the maximum effect with significant increase in chlorophyll content while 25 and 50 mg L-1 zinc oxide nanoparticle concentrations had the maximum effect on increasing carotenoid contents. According to the findings,خطای ترجمه application of zinc oxide nanoparticles at low concentration (25 mg L-1) improved water and mineral uptake and eventually resulted in an improved growth and proliferation of Melissa officinalis L. plants