Why do plants wilt when water is scarce and stand up straight when water is plentiful? Question 6Answer a. When water is plentiful it fills their central vacuole and creates turgor pressure against the rigid cell well. b. When water is plentiful, the volume of the cytoplasm increases causing the plant to stand up straight. c. When water is plentiful, plants are able to perform photosynthesis more easily which causes them to stand up and face an available light source d. When water is scarce cells in a plant are likely to die, causing the plant to wilt. This can be reversed once water is reintroduced.