Impact of radish sprouts seeds coat color on the electron paramagnetic resonance signals after plasma treatment

Recently, cold atmospheric plasma (CAP) treatment on seed germination has emerged as a useful technique to increase agriculture production, although, the mechanism of the cold plasma in seed germination is still under investigation. In this work, we studied the role of pigments in the seed coat of radish sprouts on the electron spin resonance (ESR) signals before and after CAP treatment. Radish sprouts seeds having gray color show enhanced ESR signals after the CAP treatment, whereas, no increased ESR signals were observed for brown color seeds of radish sprouts as compared to their respective control seeds. These results reveal that seeds from the same harvest year having different seed coat colors show different responses to the plasma treatment. Although ESR signal intensity can vary with the harvest year, the change in ESR signal intensity after plasma treatment depends on the seed coat color. Independently on the harvest year (2017 and 2018), CAP increased ESR signals stronger in the grey seeds in comparison to the brown ones. The results indicated that seed coat color may be an important variable for understanding differences in the extent of CAP effects on seeds.