The effect of water activated by nonthermal air plasma on the growth of farm plants: Case of maize and barley

Abstract

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.

Physiological Responses of Young Pea and Barley Seedlings to Plasma-Activated Water

“…Almost two-fold higher values for TSP in pea (compared to barley) can be linked to different storage substances in grains and seeds of barley and pea, respectively. An increase in TSP in 4-week-old plants irrigated with PAW was documented by our preceding study by Yemeli et al [ 28 ] for the same types of PAW in variants GD2 and N for barley and variants GD1 and GD2 for maize. Kučerová et al [ 26 ] showed no changes in TSP in above-ground parts of wheat plants and only slightly increased concentration in roots after application of PAW generated by transient spark discharge from tap and deionized water.…”

“…The concentrations of NO 3 − for TS, GD1 and GD2 were approximately 2.46 mM, 1.40 mM and 2.34 mM, respectively. Both plasma sources are rich providers of RONS in water, as previously shown [ 28 , 38 , 39 , 41 ]. Thanks to the almost constant pH, these RONS do not decay after plasma treatment over a period of several hours, which facilitates their application on plants.…”

“…The small difference of pH before and after the plasma treatment can be explained by the natural hydrocarbon buffer system, unlike when plasma treating deionized or distilled water where we observed a strong acidification [ 38 , 39 , 40 ]. Our previous articles also reported these slight pH changes using tap water [ 21 , 26 , 28 ]. It turns out that overall pH variations are negligible, making this parameter a non-disruptive factor of the germination process.…”

“…The activity of the antioxidant enzymes, as well as in situ visualisation of oxygen radicals, was a subject of interest also in other studies. In our previous study, we analysed the activity of SOD, G-POX and CAT in 4-week-old barley and maize plants watered with PAW [ 28 ]. The results from the barley’s above-ground parts correlate with our current barley data in the activity of SOD and partially with G-POX and CAT activities.…”

“…This method has been approved in seed sterilization, germination enhancement and plant growth promotion [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ]. Far less studies including this article have been focused on the indirect plasma treatment, where the interaction between plasma and plant material is mediated by plasma-activated water (PAW) [ 24 , 25 , 26 , 27 , 28 ]. The PAW is usually generated by performing the electrical discharges directly in water or on its surface [ 29 , 30 , 31 ].…”