Schematic representation of plant plasmodesmata. Plasmodesmata are channels that connect two adjacent plant cells to each other, thus enabling viral infection to spread between cells. Plasmodesmata comprise the plasma membrane extension, cytoplasmic sleeve, and desmotubule that is continuous with the cortical ER networks. Depending on virus species, viral cell-to-cell movement through plasmodesmata can occur in virion or RNP complex forms.