Plasmodesmata as Active Conduits for Virus Cell-to-Cell Movement
Lourdes Fernandez-Calvino, Christine Faulkner and Andy Maule
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)
It has been known for many decades that viruses need to exploit plasmodesmata as channels of cytoplasmic connectivity through plant cell walls. However, we do not yet understand the molecular mechanisms involved in moving a single infectious entity from cell to cell, although it is clear that virus-encoded movement proteins play a central role. Major progress has been made in identifying movement proteins, their associations with subcellular structures/organelles, and their biochemical properties with respect to nucleic acid-binding and physical associations with host and other viral proteins. These studies reveal a specificity in functional evolution where viruses share some similarities in their movement strategies with near and far phylogenetic groups but show few examples of processes that might apply to all or many individual viruses. Plasmodesmata also provide channels for cellular communication essential for plant growth, development and defense. As such, there is increasing attention aimed at resolving their constituent components necessary for structure and function. With the limited success of genetic screens, proteomic analysis of biochemically-enriched plasmodesmal fractions has also been pursued. Through the identification of plasmodesmal proteins we will have the opportunity to understand how movement proteins bring about the massive changes in the physical behaviour of plasmodesmata that result in the translocation of the macromolecular complexes responsible for virus infectivity read more ...