A Chungnam National University research team has developed a technology that more than triples the yield of a key antimalarial compound in sweet wormwood.

The university said Thursday that the team has developed a highly efficient cultivation strategy to enhance the growth of sweet wormwood and increase its yield of artemisinin, a key ingredient in antimalarial drugs.

The team was led by Park Jong-seok, a professor in the Department of Bio-AI Convergence and the Department of Horticulture Science.

The method involves treating sweet wormwood (Artemisia annua) seedlings with ozonated water for just 40 seconds before transplanting.

The findings were published earlier this month in Industrial Crops and Products, an international journal covering research on crops of industrial interest, under the title “Pre-transplant ozonated water soaking boosts growth and artemisinin yield in hydroponic Artemisia annua via hormesis.”

Kim Sun-woo, a doctoral student in the Department of Bio-AI Convergence, was the first author, while Park was the corresponding author.

“We confirmed that a single 40-second treatment with ozonated water before transplanting can dramatically improve the growth of sweet wormwood and increase artemisinin yield,” Park said.

He added, “We expect the technology to be used as a practical means of increasing the productivity of high-value medicinal crops grown in vertical farms and hydroponic systems.”

The university noted that ozonated water is used in agriculture for produce washing, disease control and irrigation-water sanitation, as well as in food processing, water treatment and industrial cleaning.

However, its use to promote plant growth or enhance the production of functional compounds remains largely at the research and demonstration stage.

The research team immersed whole sweet wormwood seedlings in ozonated water at various concentrations for 40 seconds before growing them hydroponically. The team then analyzed plant growth and artemisinin-related metabolites.

The results showed that treatment with ozonated water at 0.5 milligrams per liter increased the artemisinin concentration by 74.1 percent and artemisinin yield per plant by 209.8 percent, with the latter representing an approximately 3.1-fold increase compared with the control group.

The aboveground dry weight also increased by 78.1 percent, indicating that the treatment simultaneously enhanced both plant growth and artemisinin production.

The team suggested that these effects may be associated with a phenomenon known as hormesis, in which mild ozone stress activates plants’ antioxidant defense systems and promotes the production of beneficial metabolites.

Ozone rapidly decomposes after treatment, leaving little residual ozone. As the treatment is required only once before transplanting, the technology is expected to be relatively easy to integrate into hydroponic and vertical farming production processes once treatment conditions are standardized for different crops.

The research team has also conducted studies on a range of crops, including Korean mint, Japanese mustard spinach, red mustard, leaf mustard and kale, using whole-plant immersion in ozonated water or root treatment.

The university said the study demonstrates the potential of ozonated water treatment to enhance both plant growth and the production of valuable compounds in medicinal crops such as sweet wormwood.