Germination and seedling growth are important for plant production under drought stress conditions. Hence, selecting a priming technique that accelerates germination in challenging environments can aid in the early development and growth of seedlings. Applying cold plasma shows great potential for enhancing seed germination and growth. In this study, two methods of direct treatment [dielectric barrier discharge (DBD)] and indirect treatment [surface dielectric barrier discharge (SDBD)] to stimulate the germination and growth of licorice seeds (Glycyrrhiza) were investigated. To conduct a thorough analysis, various physiological parameters including seed germination, seedling growth, germination rate, germination index, germination energy, vigor index, time reach to 50% germination, seedling length, as well as catalase (CAT) and ascorbate peroxidase (APX) activities were assessed under irrigated and drought stress conditions. The results showed that the seeds treated with SDBD plasma were well able to withstand drought stress. Moreover, seed treatment with SDBD air plasma accelerated the germination speed and efficiency as well as increased the activity of CAT and APX of the treated seeds, compare to argon gas. Thus, SDBD air plasma can be used as an effective method to enhance germination and safeguard licorice seedlings from drought stress-induced damage.

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