Turgor
/TER-gor/🔬 Anatomy●● Intermediate
Also known as: turgor pressure, turgidity
Turgor pressure is the hydrostatic pressure exerted by the cell's contents (vacuole) against the cell wall. Adequate turgor keeps herbaceous plant tissues firm and upright; loss of turgor (plasmolysis) causes wilting. Turgor pressure also drives cell expansion during growth, powers stomatal opening and closing, and maintains leaf orientation. It is the reason plants revive after watering — cells re-absorb water and regain pressure.
Etymology
From Latin turgor (a swelling), from turgere (to swell)
Example
“The lettuce wilted as turgor pressure dropped in the midday heat, but recovered overnight as cells rehydrated.”