Tomato Brown Rugose Fruit Virus Is Transmissible through a Greenhouse Hydroponic System but May Be Inactivated by Cold Plasma Ozone Treatment

Authors: ZHOU, JING - Orise Fellow; Gilliard, Andrea; Ling, Kai-Shu

Submitted to: Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/21/2024
Publication Date: 4/20/2024
Citation: Zhou, J., Gilliard, A.C., Ling, K. 2024. Tomato Brown Rugose Fruit Virus Is Transmissible through a Greenhouse Hydroponic System but May Be Inactivated by Cold Plasma Ozone Treatment. Horticulturae. 10(4):416. https://doi.org/10.3390/horticulturae10040416.
DOI: https://doi.org/10.3390/horticulturae10040416

Interpretive Summary: Tomato is one of the most important vegetable crops in the U.S. and around the world. In recent years, greenhouse tomato suffered serious disease outbreaks caused by an emerging tobamovirus, tomato brown rugose fruit virus (ToBRFV). With its seed-borne and resistance breaking properties, this highly contagious virus has been reported on tomato and pepper crops in over 40 countries around the world. However, there is still no good understanding on virus epidemiology, specifically on water transmission in a recirculating hydroponic system. In this study, in collaboration with greenhouse growers in the U.S., scientists at the U.S. Vegetable Laboratory determined the infectivity of ToBRFV in water runoff samples collected from two greenhouses experienced ToBRFV infection. Furthermore, they also determined that cold plasma-generated ozone was effective in inactivating the ToBRFV infectivity in water samples spiked with known amount of virus inoculum. These results provided direct evidences to support the water-transmission of ToBRFV and the promising potential in using cold-plasma ozone as a water treatment to manage ToBRFV spreading in a greenhouse.

Technical Abstract: Recent outbreaks of tomato brown rugose fruit virus (ToBRFV) on tomato crops worldwide indicate an escalating global pandemic as the virus continues encroaching upon new territories. Compared with open-field tomato production systems, greenhouse hydroponic farms equipped with a closed-loop fertigation system may be more vulnerable to ToBRFV outbreaks given that virus-contaminated nutrient solution is captured and recirculated back into the hydroponic irrigation system. We evaluated the potential role of recirculating nutrient solution in transmission of ToBRFV. The results showed that virus-contaminated nutrient solutions collected from ToBRFV-infected tomato farms remained infectious for weeks as assessed using bioassay through mechanical inoculation. We then conducted water treatment using cold plasma-generated ozone to assess its ability to deactivate ToBRFV infectivity in water solutions that were spiked with different concentrations of virus inoculum that was prepared using fresh tomato leaf tissue. We found that the effectiveness of a cold plasma-ozone treatment was dependent on ozone concentrations (0.1 mg/L to 1.0 mg/L), periods of exposure (24 min to 72 min) and the virus contaminations (1:100 to 1:10,000) in the water. These results demonstrate that cold-plasma ozone treatment could offer a promising solution to cope with the challenge of ToBRFV transmission through a recirculating hydroponic nutrient system.