The stimulatory effect of non-equilibrium (low temperature) air plasma pretreatment on light-induced germination of Paulownia tomentosa seeds

Light-induced germination of Paulownia tomentosa seeds was used as an experimental system to investigate the effect of pretreatments by non-equilibrium (low temperature) air plasma on the germination process. Dry P. tomentosa seeds exposed to the plasma changed their germination characteristics. Non-equilibrium plasma treatments significantly increased the light sensitivity of P. tomentosa seeds. These treatments could not substitute for the light-requirements of the seeds. After a short exposure to plasma (4 to 6 minutes) treated seeds had a germination of 75%, i.e. significantly higher than the 5-30% for seeds which did not undergo pretreatment. The results suggest that the stimulatory effect of the non-equilibrium air plasma pretreatment is not a direct photoreceptor-mediated phenomenon. Possible mechanisms of this effect are discussed.