<P> Aside from storage , the main role of the central vacuole is to maintain turgor pressure against the cell wall . Proteins found in the tonoplast ( aquaporins ) control the flow of water into and out of the vacuole through active transport , pumping potassium ( K ) ions into and out of the vacuolar interior . Due to osmosis , water will diffuse into the vacuole , placing pressure on the cell wall . If water loss leads to a significant decline in turgor pressure , the cell will plasmolyze . Turgor pressure exerted by vacuoles is also required for cellular elongation : as the cell wall is partially degraded by the action of expansins , the less rigid wall is expanded by the pressure coming from within the vacuole . Turgor pressure exerted by the vacuole is also essential in supporting plants in an upright position . Another function of a central vacuole is that it pushes all contents of the cell 's cytoplasm against the cellular membrane , and thus keeps the chloroplasts closer to light . Most plants store chemicals in the vacuole that react with chemicals in the cytosol . If the cell is broken , for example by a herbivore , then the two chemicals can react forming toxic chemicals . In garlic , alliin and the enzyme alliinase are normally separated but form allicin if the vacuole is broken . A similar reaction is responsible for the production of syn - propanethial - S - oxide when onions are cut . </P>
what is the function of the central vacuole in plants
maintain turgor pressure against the cell wall