CHAPTER 14: Movement in the Plant

After the virus has entered a plant, expressed its genes, and replicated, it must move to and through the plasmodesmata of the infected cell to adjacent cells, as well as into and back out of the vascular tissue during transportation to distal parts of the plant. Each of these steps requires some function associated with viral-encoded proteins. This chapter reviews what is known about intracellular movement of the cucumber mosaic virus (CMV) RNAs and associated proteins, as well as the intercellular movement through plasmodesmata to adjacent cells and systemic movement into the vascular system of the plant, followed by subsequent cellular movement. In addition, CMV proteins and specific sequences identified as being involved in various aspects of virus movement are described, along with the effects of various natural and human-made mutations on these processes and on the subcellular localization of the CMV 3a movement protein mutants.