Players at plasmodesmal nano-channels

Plasmodesmata (PD) are the nano-channels connecting the adjacent plant cells. These functional tiny holes in the plant cell wall allow the symplasmic transport of diverse molecules such as RNA, proteins, phytohormones, metabolites and ions between the neighboring plant cells in order to conduct the both short distance and the long distance communications. Such PD-mediated symplasmic transport plays significant role in the various developmental and physiological processes in plants. To get deeper insight into the function and regulation of PD, in this review, we provide an overview on the various PD components at the cellular and the molecular level. The basic structure of PD reveals that these are membrane rich environments comprising plasma membrane (PM)-lined pores that make the continuity between the cell wall and central axial element of appressed endoplasmic reticulum (Desmotubule) in order to provide membrane and symplasmic connection between adjacent cells. Using diverse approaches, up to now more than 30 proteins including several transmembrane proteins and other non-protein components have been found to be PD associated. Next challenge will be to integrate known PD components to build complete structure of these functional nano-channels.