Entering the plasma agriculture field: An attempt to standardize protocols for plasma treatment of seeds

Abstract

Plasma treatments are currently being assessed as a seed processing technology for agricultural purposes. There is sufficient information as a proof-of-concept, but a lack of standardization in the methodology prevents a convincing evaluation of plasma treatment on seeds. It would be helpful to coordinate research efforts to make the entry for newcomers into this interdisciplinary field less overwhelming and to aid in transferring this technology into the industry by establishing a common protocol. This review presents the parameters used in the seed preparation, the plasma treatment of the seed, and the seed posttreatment. This summary of the plasma and biological parameters is intended to raise awareness about questions that need to be addressed to properly record protocol details and reproduce results for the plasma treatment of seeds.

Biochemical and Physiological Plant Processes Affected by Seed Treatment with Non-Thermal Plasma

“…Typical discharges differ in electrode arrangement, power sources, gas pressure, and include glow discharge, plasma jets, low-pressure capacitively coupled plasma (CP) discharge, corona discharge, dielectric barrier discharge (DBD), diffuse coplanar surface barrier discharge (DCSBD), etc. (for details, see reviews [ 19 , 22 , 27 , 28 , 29 , 30 ]). In this review, the common abbreviation NTP is used for plasma generated by all types of devices.…”

“…NTP does not cause thermal damage to heat-sensitive biological systems such as living cells and tissues. Therefore, this technology has many applications in biomedical technologies [ 8 , 9 , 10 , 11 , 12 ], for o has shown potential to improve agronomic seed quality by surface decontamination, germination enhancement, and promotion of plant growth, as discussed in numerous reviews published recently [ 3 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ]. Intensive research is currently being conducted on the application of NTP in agriculture, forestry, and food industries in many parts of the world.…”

RNA Sequencing of Arabidopsis thaliana Seedlings after Non-Thermal Plasma-Seed Treatment Reveals Upregulation in Plant Stress and Defense Pathways

“…Therefore, not only is the substrate different, seedling instead of seed, but the chemistry could also be different. Nevertheless, it is encouraging to see significant overlap between these studies because this promises some robustness in the experimental results, and this might be explained by using the same seed type, similar operating parameters for the plasma-seed treatment, and extraction time point [ 6 ]. The RNA extraction was performed 48 h after plasma treatment on 4-day-old seedlings, so, both studies extracted from 6-day-old seedlings, and the main difference was that plasma treatment was performed on either the seed or seedling.…”

“…It has been shown that seed germination can be accelerated, or the plant properties can be altered where root length, shoot length, harvest mass or stress and disease resistance have increased after plasma treatment [ 4 , 5 ]. Despite the numerous successful results obtained in other studies, it remains elusive which plasma treatment parameters are required to affect plant growth parameters mainly because of the plethora of physical, chemical, and biological variables [ 6 ]. Therefore, the focus has recently shifted toward analyzing the gene transcription in seedlings and plants developing from plasma-treated seeds or even analyzing the methylation on genes or proteins using quantitative PCR (qPCR) or other high throughput methods, respectively [ 7 , 8 , 9 , 10 ].…”

Treatment of Chrysanthemum Synthetic Seeds by Air SDBD Plasma

“…One of the first applications of cold plasmas was the treatments of conventional seeds [ 39 , 40 ]. This includes various applications in seed treatment with several purposes [ 41 , 42 , 43 ]. Many authors have shown that plasma treatments can increase seed germination and speed up the whole process of plantlet development [ 37 , 38 , 39 , 40 ].…”