Center of Plasma Nano-Interface Engineering, Kyushu University, Fukuoka, 819-0395, Japan.
Department of Electronics, Kyushu University, Fukuoka, 819-0395, Japan.
Sci Rep. 2021 Jan 28;11(1):2539. doi: 10.1038/s41598-021-81175-x.
The use of low-temperature plasma for the pre-sowing seed treatment is still in the early stage of research; thus, numerous factors affecting germination percentage, seedling growth, and yield remains unknown. This study aimed to estimate how two critical factors, such as harvest year and seed coat color, affect the percentage of germination and seedling growth after plasma treatment. Radish seeds stored for 2 and 1 year after harvesting (harvested in 2017 and 2018) were sorted into two colors (brown and grey) to investigate the plasma effect on harvest year and seed coat color. We analyzed the amounts of seed phytohormones and antioxidant (γ-tocopherol) were analyzed using mass spectrometry, and physical changes were studied using SEM, EDX, and EPR to understand the mechanism of plasma-induced changes in radish seeds. The obtained results revealed that plasma treatment on seeds affects the germination kinetics, and the maximal germination percentage depends on seed color and the time of seed storage after harvest. Through this study, for the first time, we demonstrated that physical and chemical changes in radish seeds after plasma treatment depends upon the seed color and harvest year. Positive effects of plasma treatment on growth are stronger for sprouts from seeds harvested in 2017 than in 2018. The plasma treatment effect on the sprouts germinated from grey seeds effect was stronger than sprouts from brown radish seeds. The amounts of gibberellin A3 and abscisic acid in control seeds strongly depended on the seed color, and plasma induced changes were better in grey seeds harvested in 2017. Therefore, this study reveals that Air scalar-DBD plasma's reactive oxygen and nitrogen species (RONS) can efficiently accelerate germination and growth in older seeds.
低温等离子体在播种前种子处理中的应用仍处于研究的早期阶段；因此，许多影响发芽率、幼苗生长和产量的因素尚不清楚。本研究旨在评估两个关键因素，如收获年份和种皮颜色，如何影响等离子体处理后种子的发芽率和幼苗生长。将收获于 2017 年和 2018 年的萝卜种子分别储存 2 年和 1 年后（收获后），按两种颜色（棕色和灰色）进行分类，以研究等离子体对收获年份和种皮颜色的影响。我们使用质谱法分析种子植物激素和抗氧化剂（γ-生育酚）的含量，使用 SEM、EDX 和 EPR 研究物理变化，以了解等离子体诱导萝卜种子变化的机制。研究结果表明，等离子体处理种子会影响种子的发芽动力学，最大发芽率取决于种子颜色和收获后种子储存时间。通过这项研究，我们首次证明了等离子体处理后萝卜种子的物理和化学变化取决于种子颜色和收获年份。与 2018 年收获的种子相比，等离子体处理对 2017 年收获的种子生长的促进作用更强。等离子体处理对灰色种子萌发的影响大于对棕色萝卜种子萌发的影响。赤霉素 A3 和脱落酸在对照种子中的含量强烈依赖于种子颜色，等离子体诱导的变化在 2017 年收获的灰色种子中更好。因此，本研究表明，Air scalar-DBD 等离子体的活性氧和氮物质（RONS）可以有效地加速较老种子的发芽和生长。
