Received: 17 March 2017 | Revised: 19 July 2017 | Accepted: 1 August 2017 DOI: 10.1002/ppap.201700059 FULL PAPER Pre-sowing seed treatment with cold plasma and electromagnetic field increases secondary metabolite content in purple coneflower (Echinacea purpurea) leaves Vida Mildaziene 1 | Giedre Pauzaite 1,2 | Zita Naucienė 1 | Asta Malakauskiene 2 | Rasa Zukiene 1 | Irena Januskaitiene 1 | Valdas Jakstas 3 | Liudas Ivanauskas 3 | Irina Filatova 4 | Veronika Lyushkevich 4 1 Faculty of Natural Sciences, Vytautas Magnus University, Vileikos str. 8, Kaunas LT-44404, Lithuania 2 Kaunas Botanical Garden,, Vytautas Magnus University, Z. E. Zilibero str. 6, Kaunas LT-46324, Lithuania 3 Faculty of Pharmacy, Medical Academy, Lithuanian University of Health Sciences, Eivenių 4, Kaunas LT-50161, Lithuania 4 B. I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, 68 Prospekt Nezavisimosti, Minsk BY- 2220072, Belarus Correspondence Vida Mildaziene, Faculty of Natural Sciences, Vytautas Magnus University, Vileikos str. 8, Kaunas LT-44404, Lithuania. Email: vida.mildaziene@vdu.lt The effects of seed treatment with cold plasma (2–7 min), vacuum (7 min), and electromagnetic field (5–15 min) on Echinacea purpurea germination and performance are studied. All treatments induce faster germination but did not change the final germination percentage, except the decrease evoked by vacuum treatment. The plants grown from all groups of treated seeds have larger height, develop more leaves, some treatments increase root weight. The content of vitamin C and phenolic acids in extracts of plant leaves from the treated groups is substantially higher in comparison to the control, so that the amount of cichoric acid per plant increased up to 3.8- fold, and amount of vitamin C per plant – up to 1.9-fold. Seed treatments induce large increase in radical scavenging activity (up to 114%) in leaf extracts. KEYWORDS cold plasma, Echinacea purpurea, electromagnetic field, phenolic acids, radical scavenging 1 | INTRODUCTION Purple coneflower, Echinacea purpurea (L.) Moench, is one of the most widely used medicinal plants and dietary supplements in Europe and North America. [1,2] Numerous attempts have been made to meet the increasing production demands of the commercially important plant biomass and to optimize the composition of pharmaceutical products, including plant breeding and various biotechnological approaches. [3,4] All parts of the plant are suitable for manufacturing of the therapeutic extracts that are mainly applied for the stimulation of the immune system. [5] The Plasma Process Polym. 2017;e1700059. www.plasma-polymers.com © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim | 1 of 11 https://doi.org/10.1002/ppap.201700059