Figure 1.

Water pathways in plant cells. Light blue arrows schematize the water pathways in isolated (A) and connected cells (B). In isolated cells, water entering the vacuole moves through the cell wall (cw) and the biomembranes, i.e., the plasma membrane (pm) and the tonoplast (tp). In addition to these pathways, in connected cells water can pass from one cell to the adjacent neighbor through simplastic pathway. Here, the impact of the imposed osmotic gradient is likely to be more attenuated. The difference of magnitude between the water potential of the cytoplasm (ψ_C) and the vacuole (ψ_V) mediates turgor maintenance (ψ_C >> ψ_V).