Growth control of Marchantia polymorpha gemmae using nonthermal plasma irradiation

Several studies have documented that treatment by cold atmospheric pressure plasma (CAP) on plants foster seed germination and growth in recent years. However, the molecular processes that underlie the action of CAP on the seeds and plants remain mostly enigmatic. The effects of CAP on seeds could significantly differ depending on their status, thus obstructing detailed molecular analyses. We here introduce gemmae of Marchantia polymorpha, a basal liverwort, as a novel model plant material suitable for CAP research. Treating the gemmae with CAP for a constant time interval at low power resulted in consistent growth enhancement, while growth inhibition at higher power in a dose-dependent manner. These results distinctly demonstrate that CAP irradiation can positively and negatively regulate plant growth depending on the plasma intensity of irradiation, offering a suitable experimental system for understanding the molecular mechanisms underlying the action of CAP in plants.