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.