A new study by VIRTIGATION partner Volcani Center, published in the Plant and Soil journal, unveiled new strategies for controlling ToBRFV contamination in soil through disinfection.
Background and aims of the study
Tobamoviruses are highly stable soil-borne pathogens, posing a challenge to a monoculture practice. The VIRTIGATION Volcani Center scientists studied biochemical and physical properties of tobamovirus virions by analyses of tobacco mosaic virus (TMV). Little is known about tomato brown rugose fruit tobamovirus (ToBRFV) regarding longevity in soil and virion stability. They sought to determine ToBRFV longevity in naturally-contaminated soil and study virion stability in a range of acidic and alkaline conditions. The Israeli team did this to promote new strategies for soil remediation.
Methods employed to improve ToBRFV control in soil
The Volcani Center investigators tested ToBRFV longevity in naturally-contaminated soil by collecting an earth pile after a growth-cycle of ToBRFV-infected tomato plants. They sampled the soil at different time points and planted root-truncated tomato seedlings. By testing virus infectivity on Nicotiana glutinosa, they determined virion stability at a range of pH values. The Israeli team also amplified large genome segments by using RT-PCR, and by transmission electron microscopy (TEM) visualization.
Promising results obtained with alkaline soil disinfection
The Volcani Center scientists found that ToBRFV-infectivity in naturally-contaminated soil profoundly reduced by day 184 of pile-age and was abolished between 205 and 385 days of pile-age. The virion stability and genome integrity preserved over the pH range of 2-10. At pH 1, they observed reduction of ToBRFV-infectivity and efficiency of large genome segment amplifications. At pH values above 10, the Israeli team visualized modified particle morphologies by TEM, and reported abolishment of virus infectivity. The Volcani Center VIRTIGATION researchers’ treatment of ToBRFV-contaminated soil with an alkaline chlorinated-trisodium phosphate solution profoundly reduced soil-mediated virus infection of root-truncated tomato seedlings.
Conclusions of the study & future research perspectives
Through their new study, VIRTIGATION Volcani Center scientists have demonstrated that pH values above 10 compromised ToBRFV particle morphology, genome integrity, and virus infectivity. They also showed that an alkaline disinfectant enhanced soil remediation following natural ToBRFV contamination. For future research perspectives, the Israeli team concludes that to prevent soil-mediated ToBRFV infection, enhancement of soil disinfection could be provided by the use of alkaline disinfectant solutions or addition of alkaline solutions to other disinfection strategies such as soil steaming or solarization.
More info about Volcani Center's new ToBRFV study
The full version of Volcani center’s study in the Plant and Soil journal titled “Studying tomato brown rugose fruit virus longevity in soil and virion susceptibility to pH treatments helped improve virus control by soil disinfection” is available online here since 30 April 2024. It has been authored by two of Volcani Center’s principal investigators in VIRTIGATION, Aviv Dombrovsky and Elisheva Smith. The dataset underlying Volcani Center’s peer-reviewed, open access scientific publication is available here. Find out more about VIRTIGATION’s scientific publications on our website here.
