Arabidopsis seedlings treated with plasma on cotyledon induces cell death. (a) Phenotype of indicated treatment after 3 days incubation in long day condition. Scale bar = 1 mm. (b) Trypan blue staining of cotyledon of indicated treatment. (c) Total chlorophyll level of seedlings from indicated conditions. 1 sec, 3 sec, and 6 sec = plasma treatment for indicated time. Error bar = SD. Student’s t-test were used to indicate significant difference from Mock treatment, * < 0.05, ** < 0.01, *** < 0.001.