Newswise — WASHINGTON, D.C., October 21, 2015 -- Food scientists and farmers alike are keenly interested in boosting crop yields and shortening harvest times, without affecting food safety. A team of researchers led by plasma engineer Kazunori Koga, an associate professor at Kyushu University in Japan, has now developed a new technique to safely achieve both goals using a non-thermal plasma -- a type of partially ionized, low-temperature gas currently used in a wide variety of applications including decontaminating ready-to-eat foods and their packaging, sterilizing medical instruments, reducing pollutants in exhaust gas, and even for wound healing and cancer therapy.

Koga will describe the method at the AVS 62nd International Symposium and Exhibition, held Oct. 18-23, in San Jose, Calif.

Along with his graduate students Thapanut Sarinont and Takaaki Amano and other colleagues, Koga used a dielectric barrier discharge (DBD) instrument to irradiate seeds of Arabidopsis thaliana L., a small flowering plant in the mustard family that is commonly used in research laboratories. The DBD device generates a 9.2-kilovolt, 0.2-ampere nonthermal plasma containing reactive oxygen species, reactive nitrogen species, photons, ions, and electrons.

After three minutes of plasma irradiation, the seeds were grown on rockwool until the harvest stage (the time when the first seeds were harvested from the growing plants.) During the experiment the area of two of the primary leaves of each resulting plant was measured, as was the weight of the seeds produced.

Compared to non-irradiated plants, the plasma treatment led to a 7 percent shorter harvest period (reducing it from 71 to 66.5 days, on average), and to a 12 percent increase in seed weight and a 30 percent increase in primary leaf size. The entire genomic sequence of Arabidopsis thaliana L. is known, so the researchers were able to screen seeds for any genetic mutations that might have been induced by the treatment. “So far, we have found no deleterious effect such as genetic mutations from plasma irradiation,” Koga said.Irradiation with the nonthermal plasma leads to the activation, apoptosis (or programmed suicide), and degradation of cells. Essentially, said Koga, the treatment “speeds up the cell cycle so the plant and seeds grow faster overall,” with reactive oxygen species playing a key role in the effects. “Using the genome database, we expect to identify the growth enhancement mechanism in detail.”

“We also clarified that plants from plasma-treated seeds contain more glucose. This may bring about more tasty crops and higher yield of bioethanol,” he added.

The researchers currently are developing a large-scale seed treatment device in collaboration with a Japanese company. “We would like to collaborate not only with Japanese agricultural companies but also with companies worldwide, in order to develop practical applications of our results,” Koga said.


Presentation PS+SE-FrM5, “Improving of Harvest Period and Crop Yield of Arabidopsis thaliana L. using Nonthermal Atmospheric Air Plasma,” is at 9:40 a.m. on Friday, Oct. 23, 2015.


The symposium takes place Oct. 18-23, 2015 at the San Jose Convention Center.


Main symposium website: Program: http://www.avssymposium.orgMedia Center: San Jose Convention Center:


To request free press registration, please contact Jason Socrates Bardi at [email protected] and Della Miller at [email protected].


Founded in 1953, AVS is a not-for-profit professional society that promotes communication between academia, government laboratories, and industry for the purpose of sharing research and development findings over a broad range of technologically relevant topics. Its symposia and journals provide an important forum for the dissemination of information in many areas of science and technology, enabling a critical gateway for the rapid insertion of scientific breakthroughs into manufacturing realities. See:

Meeting Link: AVS 62nd International Symposium & Exhibition