Nucleic Acid-Based Assay for the Diagnosis of Viral Pathogens

Abstract

A knowledge of the genetic structure and evolution of plant virus populations is crucial to predict the
possible emergence of resistance-breaking pathotypes, as recently demonstrated with Tomato spotted wilt virus. The
advent of analytical techniques for the fast identification of changes in nucleotide sequences, and the need to analyze
the benefits and risks of new control strategies, such as those offered by virus-resistant transgenic plants, has led to
an increasing interest in techniques exploiting the fine analysis of the virus genome. The choice of an analytical
technique should depend on the goal of the analysis, as well as on the sensitivity and cost of the technique. Some
techniques provide only qualitative data that can be used to identify variants, whereas others can be used to assess
how different the identified variants are. Such estimates can be given by the amino acid composition of the viral
proteins, or by restriction fragment length polymorphism (RFLP) analysis. DNA microarray technology is another
promising tool which meets both the diagnostic and the detection needs of modern plant virology.