Exploring plant virus diversity in wastewater and reclaimed water through metagenomic analysis

The use of reclaimed water for agricultural activities is being widely employed to address drought and water scarcity. Nevertheless, the disinfection processes do not consistently facilitate the complete removal of all eukaryotic viruses within these reclaimed waters. Consequently, it may pose a risk not only to humans but also to irrigated plants. We analyzed 48 influent and 48 effluent samples from 4 different wastewater treatment plants (WWTPs) by high-throughput sequencing (HTS) to characterize plant-associated virome over a one-year period. Our results showed high levels of plant viruses in both influent and effluent waters. The predominant family identified was Virgaviridae, recognized for its high environmental persistence. Notably, the identification of Tomato Brown Rugose Fruit virus (ToBRFV), classified as a harmful organism by the European Union and subject to strict containment measures to control its spread, highlights the importance of monitoring reclaimed water to mitigate the spread of such viruses into the environment. These findings underscore the need of analyzing reclaimed water from a One Health perspective, ensuring its safety for humans, animals, plants, and the environment alike.