Non-Thermal Plasma-Activated Water: A Cytogenotoxic Potential on Triticum aestivum

Non-thermal plasma-activated water (PAW) is used in agriculture to decontaminate the seed/grains surface, with possible positive effects on physiological processes. In the present study, PAW was generated in ambient air at atmospheric pressure in eight variants with pH and different doses of reactive species (H2O2, NO3-). We explored the indirect effect of PAW on wheat grains while focusing on genetic material by cytogenetic monitoring. All PAW variants caused clastogenic and aneugenic events of the genetic material, with different intensities, in a dose-dependent manner of reactive species in plasma composition. PAW with the highest doses of H2O2 (13-22 mg/L) and NO3- (49-68 mg/L) at pH 3.8-4.1 decreased the mitotic index the most and induced the most frequent genetic abnormalities, out of which chromosomal bridges and micronuclei were dominant. In correlation with this damage at the nucleus level, the germination rate and root and shoot length of wheat sprouts decreased significantly only in the variants with the highest doses of reactive species. PAW with the lowest doses of H2O2 (1-5 mg/L) and NO3- (8-15 mg/L) at pH 5.5-5.1 induced a much lower cytogenotoxic potential, maintained a germination rate comparable to the control and even significantly stimulated root and shoot length growth. Thus, the effects of PAW depend highly on the dose of reactive species and on pH.