Mechanism of Action of Viral Suppressors of RNA Silencing
from: Recent Advances in Plant Virology (Edited by: Carole Caranta, Miguel A. Aranda, Mark Tepfer and J.J. Lopez-Moya). Caister Academic Press, U.K. (2011)
RNA silencing is an evolutionarily conserved sequence-specific gene-inactivation system that also functions as an antiviral mechanism in higher plants and insects. To overcome this defence system, viruses encode suppressors of RNA silencing, which can counteract the host silencing-based antiviral process. In the past, more than 50 individual viral suppressors have been identified from almost all plant virus genera, underlining their crucial role in successful virus infection. Viral suppressors are considered to be of recent evolution, and they are surprisingly diverse within and across kingdoms, exhibiting no obvious sequence similarity. Virus-encoded silencing suppressors can target several key components in the silencing machinery, such as silencing-related RNA structures and essential effector proteins and complexes. This chapter reviews the most recent progress in our understanding of the mechanism and function of viral suppressors of antiviral RNA silencing in plants read more ...