Plants have cell walls to give them more structural strength. in order to facilitate movement of molecules from one plant cell to another, there are channels called that run through the cell walls

The channels that run through the cell walls are called Plasmodesmata. They are porous channels that allow for water to move in the cell wall. They are needed because the cellulose cell wall is too rigid for water to move through otherwise. The similar type of organelle in animal cells is called gap junctions.