Seed Priming with Non-thermal Plasma Modified Plant Reactions to Selenium or Zinc Oxide Nanoparticles: Cold Plasma as a Novel Emerging Tool for Plant Science

This research explored the capability of seed priming with the non-thermal plasma to modify reactions of Melissa officinalis, an important medicinal plant, to zinc oxide (nZnO) or selenium (nSe) nanoparticles. The germinating seeds were primed with the plasma (0.84Wcm(-2) surface power densities) under different durations (0, 50, 90, and 120s); after that the primed seeds were cultured in petri dish containing Hoagland nutrient solution manipulated with various concentrations of nSe (0, 2, 5, 10, and 20 mgl(-1)) or nZnO (0, 50, and 250 mgl(-1)). The plasma treatments not only improved growth-related characteristics (stem length, root length, and leaf wide) and biomass accumulation but also toxicity signs of nSe (5, 10, and 20 mgl(-1)) were partly mitigated by the plasma priming. Interestingly, the plasma treatments induced peroxidase activity about 46%. Similarly, inductions in the activity of phenylalanine ammonia lyase were recorded in the plasma-primed seedlings. The correlations between the evaluated traits were found to be significant. Taken collectively, it could be exploited for delivering a novel tool regarding seed priming, biofortification, and seed/seedling-derived foods.