Name an organelle which maintains the turgidity and rigidity of mature plant cells.

(N/A) The organelle responsible for maintaining the turgidity and rigidity of mature plant cells is the $Vacuole$. In plant cells, large central vacuoles occupy up to $90\%$ of the cell volume. The cell sap contained within the vacuole exerts pressure against the cell wall, known as turgor pressure, which provides structural support and rigidity to the plant.