chapter  21
Virus-Induced RNA Silencing in Plants
WithM. Barciszewska-Pacak, B. Grabowska, J. Wojciechowicz, A. Pacak, M. Figlerowicz
Pages 20

Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340

According to the central dogma of molecular biology, the flow of genetic information proceeds from DNA through RNA to proteins. In the case of viruses, this principle concerns only those whose genome is composed of DNA. In viruses using RNA as the only carrier of genetic information, the above scheme is subjected to a simplification: RNA → proteins. As a result, during the replication of viral genomes, not doublestranded (ds) DNA, but dsRNA, is formed. Recently, it has been postulated that plants took advantage of this unique feature of RNA-based viruses and developed a specific antiviral system exploiting the RNA silencing phenomenon.1-3 It is thought that a plant immune system against viruses is based on the same general mechanism that is involved in other processes of sequence-specific RNA degradation, e.g., posttranscriptional gene silencing (PTGS), and gene cosuppression observed in plants, gene quelling in fungi, or RNA interference (RNAi) in animals.4,5

This chapter provides basic information concerning the mechanism and potential application of virus-induced RNA silencing. It also contains several protocols that we currently use in our laboratory to study this phenomenon.