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The present study aims to define the effects of Cold Atmospheric Pressure Plasma (CAPP) exposure on seed germination of an agriculturally important crop, soybean. Seed treatment with lower doses of CAPP generated in ambient air and oxygen significantly increased the activity of succinate dehydrogenase (Krebs cycle enzyme), proving the switching of the germinating seed metabolism from anoxygenic to oxygenic. In these treatments, a positive effect on seed germination was documented (the percentage of germination increased by almost 20% compared to the untreated control), while the seed and seedling vigour was also positively affected. On the other hand, higher exposure times of CAPP generated in a nitrogen atmosphere significantly inhibited succinate dehydrogenase activity, but stimulated lactate and alcohol dehydrogenase activities, suggesting anoxygenic metabolism. It was also found that plasma exposure caused a slight increment in the level of primary DNA damage in ambient air- and oxygen-CAPP treatments, and more significant DNA damage was found in nitrogen-CAPP treatments. Although a higher level of DNA damage was also detected in the negative control (untreated seeds), this might be associated with the age of seeds followed by their lower germination capacity (with the germination percentage reaching only about 60%).

Zinc (Zn) is an essential microelement involved in various plant physiological processes. However, in excess, Zn becomes toxic and represents serious problem for plants resulting in Zn toxicity symptoms and decreasing biomass production. The effect of high Zn and its combination with silicon (Si) on ionome and expression level of ZmLsi genes was investigated in maize (Zea mays, L; hybrid Novania). Plants were cultivated hydroponically in different treatments: control (C), Zn (800 μM ZnSO4 · 7H2O), Si5 (5 mM of sodium silicate solution), and Si5 + Zn (combination of Zn and Si treatments). Growth of plants cultivated for 10 days was significantly inhibited in the presence of high Zn concentration and also by Zn and Si interaction in plants. Based on principal component analysis (PCA) and mineral element concentration in tissues, root ionome was significantly altered in both Zn and Si5 + Zn treatments in comparison to control. Mineral elements Mn, Fe, Ca, P, Mg, Ni, Co, and K significantly decreased, and Se increased in Zn and Si5 + Zn treatments. Shoot ionome was less affected than root ionome. Concentration of shoot Cu, Mn, and P decreased, and Mo increased in Zn and Si5 + Zn treatments. The PCA also revealed that the responsibility for ionome changes is mainly due to Zn exposure and also, but less, by Si application to Zn stressed plants. Expression level of Lsi1 and Lsi2 genes for the Si influx and efflux transporters was downregulated in roots after Si supply and even more downregulated by Zinc alone and also by Zn and Si interaction. Expression level of shoot Lsi6 gene was differently regulated in the first and second leaf. These results indicate negative effect of high Zn alone and also in interaction with Si on Lsi gene expression level and together with ionomic data, it was shown that homeostatic network of mineral elements was disrupted and caused negative alterations in mineral nutrition of young maize plants.

The effects of plasma‐activated water (PAW) generated by nonthermal air plasmas of transient spark with water electrospray or atmospheric glow discharge were investigated on maize (Zea mays L. var Saccharata) and barley (Hordeum vulgare L.) seedlings. PAW is characterized by measuring concentrations of reactive oxygen and nitrogen species (H2O2, , ). After 4 weeks of plants growth, the effects of PAW are analyzed by measuring plant growth and physiological parameters: plant length and fresh weight, photosynthetic pigments concentration and photosynthesis rate, total soluble proteins, antioxidant enzyme activity, and DNA damage. The results suggest that PAW, depending on chemical composition, has the potential to improve the plant growth and influence the physiological parameters, while causing no harmful DNA damage.