Central vacuoles are important organelles in plant cells that store sugar, ions and water for plants, regulate waste and help plants retain their shape. Central vacuoles exist in all plant cells, surrounded by a thin layer of a single membrane. These versatile organelles appear empty and shriveled when viewed under the microscope, but prove quite flexible, expanding more than 95 percent of their smallest size when filling with water.
Central vacuoles serve as primary water storage centers for plants, retaining much of the water plants ingest during the day. They change shape after filling with water, performing dual duties of acting as reservoirs and giving plant structures shape. Upon reaching size capacity, central vacuoles expand outward, putting pressure on the surrounding cytoplasm. This force, called the turgor pressure, makes cells tight and strong. This rigidity gives surrounding plant parts, such as leaves and stems, distinct structures. When central vacuoles lose water, the leaves and stalks shrivel and wilt.
Central vacuoles also help plants process food. Plants produce sugar, which deposits into plant cells, along with ions and nutrients. The central vacuoles also capture and eliminate otherwise toxic substances, keeping plants healthy. Collection of hazardous substances in the reservoirs of central vacuoles makes plants appear unappetizing to potential predators, providing safety for plants.