turgere

Turgere is a term derived from Latin, meaning to swell or be turgid. In biological contexts, it specifically refers to the state of being swollen and firm, primarily due to the uptake of water by cells. This turgor pressure is a crucial factor in maintaining the rigidity and structure of plant tissues, a phenomenon known as turgidity.

When plant cells absorb water through osmosis, the vacuole within the cell expands. This expansion pushes the cytoplasm and the cell membrane against the cell wall. The cell wall, being relatively rigid, resists this outward pressure, creating an internal hydrostatic pressure known as turgor pressure. This pressure is what gives plants their upright posture and prevents wilting.

Turgor pressure plays a significant role in various plant processes. For instance, it drives cell expansion, which is essential for growth. It also enables movements in plants, such as the opening and closing of stomata (pores on the leaf surface for gas exchange) and the rapid movements observed in sensitive plants like the Venus flytrap or Mimosa pudica.

Conversely, a lack of sufficient water leads to a decrease in turgor pressure, causing the cells to become flaccid and the plant to wilt. The reversibility of this process, where wilting plants can regain their turgidity upon rehydration, highlights the dynamic nature of turgor pressure in plant physiology. Beyond plants, the concept of turgidity can also be applied to certain protozoa and microorganisms where internal water pressure contributes to their form.