Atmospheric plasma induced ROS accumulation across the treated area in cotyledon. (a) DCFDA fluorescence image of cotyledon treated with plasma for indicated times (s). Representative image were determined from 5 experiments for each conditions. (b) Relative ROS level was measured in direct plasma treated seedlings and indirectly treated samples. To measure ROS level, we used 20 cotyledons treated with indicated conditions and DCFDA signal intensity were measured with same exposure time taken fluorescence image data. Signal was measured for whole cotyledon as mean grey value. Error bar = SD. Student’s t-test were used to indicate significant difference from Mock treatment, * < 0.05, ** < 0.01, *** < 0.001. (c) DCFDA fluorescence image of cotyledon treated with 6 seconds of plasma or not by confocal microscope. Grey signals in epidermis images are propidium iodide fluorescence to visualize cell walls and nucleus, and grey signals in mesophyll images are chlorophyll auto-fluorescence to visualize relative plastid location. Representative image were determined from 5 experiments for each conditions.