Whitefly transmission of plant viruses

Whitefly-mediated transmission of circulative plant viruses involves highly specific, coevolved intramolecular interactions between the viral-encoded determinants and the receptor-like molecules of insect origin that interact to confer virus–vector specificity. This chapter describes the current physical, behavioral, cellular, and molecular aspects of whitefly-mediated transmission for the four plant virus genera known to be transmitted by one or more whitefly vector species: Begomoviruses, Carlaviruses, Criniviruses and Potyviruses. However, as very little is known about the cellular or molecular mechanisms of transmission of noncirculative whitefly-transmitted viruses, much of the review in the chapter concerns results of recent studies for begomoviruses and their whitefly vector, B. tabaci, and analogies that may be drawn from knowledge of other wellstudied circulative plant virus groups and their vector relations. Understanding the basis for the behavioural, cellular, and molecular phenomena that underlie whitefly-mediated transmission of plant viruses should provide great opportunities for directing the disruption of specific targets to interfere with the transmission process at critical and vulnerable points in the pathway.