Unusual features of pomoviral RNA movement

Abstract

Potato mop-top pomovirus (PMTV) is one of a few viruses that can move systemically in plants in the absence of the capsid protein (CP). Pomoviruses encode the triple gene block genetic module of movement proteins (TGB 1, 2, and 3) and recent research suggests that PMTV RNA is transported either as ribonucleoprotein (RNP) complexes containingTGB1 or encapsidated in virions containingTGB1. Furthermore, there are different requirements for local or systemic (long-distance) movement. Research suggests that nucleolar passage of TGB1 maybeimportant for the long-distance movementofbothRNP and virions. Moreover, and uniquely, the long-distance movement of the CP-encoding RNA requires expression of both major and minor CP subunits and is inhibited when only the major CP sub unit is expressed.This paper reviews pomovirus research and presents a current model for RNA movement. © 2011 Torrance, Wright , Crutzen, Cowan, Lukhovitskaya, Bragard and Savenkov.