If a cell is surrounded by water or a solution more dilute than its contents (i.e. Having lesser concentration of solutes and higher concentration of water), the water tends to move into a cell vacuole by osmosis. As the water enters the vacuole, it increases in size and pushes the cell contents against the wall. The plant cell does not burst as the cell wall is fairly strong and relatively inelastic. However, the cell wall cannot expand beyond a certain limit. The cell wall thus prevents over-expansion of the cell by exerting an inwardly directed or an opposing pressure which prevents the entry of more water into the cell. The cell in this state becomes turgid. The condition thus produced in the cell is called turgor and the internal pressure exerted on the cell wall is called turgor pressure. When all the cells in a leaf and stem are turgid, the plant structures like leaves and young branches will be stiff, firm and upright. If the cells somehow lose water, the cell will lose turgor and will become flaccid (soft). The leaves with flaccid cells become soft and the stem droops. Thus plant cells with reduced turgor due to loss of water is said to be wilting. Turgor plays an important role in maintaining the shape of the soft tissues in plants. The movement of certain plant parts also results from the changes in their turgor.