In this study, we analyzed seed germination, seedling growth, and physiological aspects after treatment
with high voltage nanosecond pulsed plasma and micro DBD plasma in spinach (Spinacia oleracea L.), a
green leafy vegetable known to have low germination rate. Both germination and dry weight of seedlings
increased after high voltage pulse shots were applied to spinach seeds. However seeds treated with many
shots (10 shots) showed a decrease in germination rate and seedling growth. Seeds treated with air DBD
plasma exhibited slightly higher germination and subsequent seedling growth than those treated with
N2 plasma. Seed surface was degenerated after treated with high voltage pulsed plasma and micro DBD
plasma but no significant difference in the degree of degeneration was observed among micro DBD
plasma treatment time. Level of GA3 hormone and mRNA expression of an amylolytic enzyme-related
gene in seeds were elevated 1 day after treatment with high voltage pulsed plasma. The relative
amount of chlorophyll and total polyphenols in spinach seedlings grown from seeds treated with air DBD
plasma was increased in 30 s, 1 min, and 3 min treatments. Taken together, our results suggest a possibility
that plasma can enhance seed germination by triggering biochemical processes in seeds.