Next-Generation Molecular Diagnostics for Plant Viruses

Viral disease is a major constraint for the yield loss in many economically important crops and ultimately causes economic losses. Plant viruses are distributed from one infected crop to nearby and distant crops either due to mechanical injuries or by their specific insect vectors. From time to time, new plant viruses such as Papaya ringspot virus, Chili leaf curl virus, Citrus tristeza virus, and Tomato yellow leaf curl virus emerge and re-emerge and become the major reason of outbreak of important viral diseases of crops. Many times, such diseases paralyze the economy of many countries due to severe yield losses. In developing countries like India, the management of such diseases is not practicable; therefore, the only way to eradicate such viruses is early detection and surveillance of the disease. Field-based easy diagnostic methods such as RPA, LAMP, and CRISPR/Cas have drawn the attention of researchers to develop a point-of-care testing system. Especially, clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) is an emerging technology for gene editing and diagnostics development. Several rapid nucleic acid diagnostic kits have been developed and validated using Cas9, Cas12, and Cas13 proteins. This book chapter summarizes the CRISPR/Cas-based next-generation molecular diagnostic techniques and portability of devices for field-based utilization.