Strategies for simultaneous detection of multiple plant viruses

Plants are infected by a wide range of viruses. Many cause devastation of plants and crops resulting in significant economic losses and threats to the viability of certain horticultural and agricultural industries. Resources available for routine detection of plant viruses tend to be limited. This means that techniques adopted for routine diagnosis must be of low cost yet sensitive and reliable. Approaches that allow simultaneous detection of multiple plant viruses (multiplexing) reduce the number of tests required, reagent usage, time for analysis, and consequently, the cost. Multiplex polymerase chain reaction (PCR), polyvalent PCR, nonisotopic molecular hybridization techniques, real-time PCR, and array technologies allow simultaneous detection of multiple plant viruses. The increased sensitivity achieved with some techniques, such as real-time PCR, permits the use of simple, low-cost target isolation methods such as direct binding, tissue printing, or immunocapture. These result in reduced overall cost. Multiplexing techniques have the capacity for simultaneous broad-spectrum and specific identification by combining primers and (or) probes that target various taxonomic levels such as family, genus, and species. Polyvalent PCR and broad-spectrum probes have the potential to detect unknown or uncharacterized viruses, improving our ability to monitor and successfully control these pathogens. Techniques such as microarray analysis offer the potential for development of a single biochip that may facilitate detection of all viruses affecting a particular crop (e.g., a cucurbit or potato biochip). This may be expanded in time to the detection of every pathogen, including viruses, affecting a particular plant.