Emerging technologies for in-field plant virus detection: innovations and future directions.

Plant virus infections pose a substantial threat to crop quality and productivity, contributing to considerable economic losses in global agriculture annually. Traditionally, laboratories have widely adopted serological techniques, such as ELISA, and molecular methods, including quantitative PCR, for virus diagnostics. More recently, sophisticated next-generation sequencing approaches have been introduced to improve the efficiency and reliability of virus detection and identification. However, the development of sensitive, rapid and low-cost methods for the on-site detection, quantification and identification of plant viruses remains an ongoing challenge and is still in its early days. Point-of-care technologies have not fully realized their potential in agriculture due to numerous challenges, such as the elevated cost of development, lack of standardized validation and insufficient field testing. Therefore, future success depends on addressing these technical, economic and regulatory hurdles, as well as considering the specific user needs within the agricultural context. In this mini-review, recent advancements in biosensing for on-site plant virus monitoring, involving nanotechnology-based sensors, clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated (Cas) systems, electrochemical and modern field-effect transistor-based sensors offering high sensitivity, speed and portability, are discussed. These technologies, when integrated with smartphone applications and/or machine learning modules, could enable real-time, field-deployable diagnostics for early disease management and sustainable agriculture. The aim is to raise awareness among plant virologists about this panel of emerging diagnostic concepts that could help improve current methods, ultimately facilitating the management of plant viral diseases.