Concentrates on symplasmic transport of small molecules, although the cell-to-cell transport of macromolecules will also be discussed. This book characterize the efficiency of symplasmic transport, mechanisms of molecule passage via plasmodesmata, and the external and internal factors that regulate plasmodesmatal conductivity. In this context, the book focused on the role of symplasmic domains in plant development, as well as the influence of environmental stresses on the plasmodesmata. Besides cell-to-cell symplasmic transport, the significance of long-distance symplasmic transport of solutes in phloem elements is also reviewed. Symplasmic Transport in Vascular Plants presents the mechanism of phloem transport, the processes of symplasmic loading and unloading, as well as the role of pre- and post-phloem transport, with special attention paid to symplasmic transport in wood. Finally, the relevance of the spread of both macromolecules and viruses, via plasmodesmata, is presented.