Seed priming and irrigating with plasma-activated water improve the growth and drought resistance in Poa pratensis

Abstract Background Poa pratensis L. is a perennial grass commonly used for ecological restoration due to its rapid growth rate and strong adaptability. It is considered an excellent choice for soccer fields and urban green spaces because of its high wear resistance and durability. this is the first report demonstrating the co-application of seed priming and plasma-activated water irrigation for enhancing drought resistance in P. pratensis. This study aimed to examine the influence of seed priming and irrigation with PAW on the growth of P. pratensis and its ability to endure drought conditions. The experiment was conducted in a greenhouse in 2023, using a completely randomized design. Seeds were primed with either normal water (control group) or PAW and then sown in pots containing standard soil. The experiment included six treatments: three PAW management strategies—watered normally (WW, control group), seeds primed with PAW and irrigated with normal water (PW), and a combination of both methods (PP: primed and irrigated with PAW)—under both drought and non-drought stress conditions. Results The findings indicated that drought stress significantly decreased various growth parameters, including fresh weight (21% reduction), dry weight (27% reduction), chlorophyll levels (12% reduction), and the activities of the enzymes ascorbate peroxidase (APX) and catalase (CAT) (22% and 5% reductions, respectively) in P. pratensis. Conversely, drought stress increased the levels of several compounds: carotenoids (24% increase), malondialdehyde (MDA) (81% increase), proline (80% increase), soluble carbohydrates (15% increase), and the enzyme activity of guaiacol peroxidase (GPX) (36% increase). Under drought conditions, seed priming with PAW led to a decrease in MDA (21%) and an increase in fresh weight (approximately 13%) and dry weight (about 25%). Total chlorophyll increased by around 30%, while proline and soluble sugar content rose by 14% and 50%, respectively. The activities of APX, CAT, and GPX enzymes increased by 18%, 4%, and 11%, respectively. In summary, the combination of seed priming and irrigation with PAW under drought conditions reduced MDA content by 28% and enhanced plant biomass (fresh weight by 13% and dry weight by 21%), photosynthetic pigments (total chlorophyll by 17%), and osmoprotectants (proline by 56% and soluble carbohydrates by 11%). The activities of APX, CAT, and GPX also increased significantly—by 16%, 2%, and 16%, respectively. Conclusions PAW has been shown to improve drought stress in P. pratensis by reducing lipid peroxidation and increasing levels of photosynthetic pigments, osmoprotectants, and antioxidant enzyme activity. The results indicate that the most beneficial outcomes occur when seed priming is combined with PAW irrigation. This technology could serve as a cost-effective and sustainable method for enhancing growth and drought tolerance in plants, including P. pratensis, under water-stressed conditions. Further studies are necessary to explore this effect on additional plants and to better understand its details and possible mechanisms in future research.