Skip to Content

Turgor pressure

« Back to Glossary Index

**Fundamentals of Turgor Pressure:**
– Etymology: Originates from Latin turgidus meaning swollen or inflated, first recorded in the 1610s.
– Mechanism: Osmosis facilitates water flow between regions of different solute concentrations, influencing turgidity and cell growth.
– Importance: Maintains cell shape and rigidity, supports plant processes, and aids in nutrient transport.
– Factors Affecting Turgor Pressure: Osmotic pressure, cell wall elasticity, water availability, cell size, and solute concentration.

**Turgor Pressure in Plants:**
– Regulation: Controlled by osmosis within plant cells, facilitating growth and structural changes.
– Dispersal and Transport: Regulates transport proteins, aids in solute pumping, and facilitates nutrient transport.
– Flowering and Reproduction: Influences petal blooming, anther dehiscence, pollen tube growth, and seed dispersal mechanisms.

**Turgor Pressure in Microorganisms:**
– Fungi: Significant for substrate penetration, hyphal growth, and invasive mechanisms.
– Protists: Utilize contractile vacuoles for water regulation in hypotonic solutions, avoiding lysis.
– Diatoms: Control cell expansion and sperm release, with turgor-resistant cell walls.
– Cyanobacteria: Affects gas-vacuole capacity, gas accumulation, and water blooms.

**Measurement and Techniques:**
– Units and Equivalents: Commonly measured in bars, MPa, or newtons per square meter, with 1 bar equivalent to 0.1 MPa.
– Methods: Water potential equations, pressure bomb technique, atomic force microscopy, pressure probes, and micro-manipulation probes for quantifying turgor pressure.

**Theoretical Speculations and Physiological Implications:**
– Negative Turgor Pressure: Speculated in dehydrated cells and debated in xerophytic plants.
– Cellular Processes: Crucial for plant growth, fungal mechanics, cyanobacteria buoyancy, seismonastic reactions, and seed dispersal mechanisms.
– Physiological Implications: Link to water relations, osmotic pressures, silicification in diatoms, gas vesicle collapse in cyanobacteria, and alternative mechanisms in plant tip growth.

Turgor pressure (Wikipedia)

Turgor pressure is the force within the cell that pushes the plasma membrane against the cell wall.

It is also called hydrostatic pressure, and is defined as the pressure in a fluid measured at a certain point within itself when at equilibrium. Generally, turgor pressure is caused by the osmotic flow of water and occurs in plants, fungi, and bacteria. The phenomenon is also observed in protists that have cell walls. This system is not seen in animal cells, as the absence of a cell wall would cause the cell to lyse when under too much pressure. The pressure exerted by the osmotic flow of water is called turgidity. It is caused by the osmotic flow of water through a selectively permeable membrane. Movement of water through a semipermeable membrane from a volume with a low solute concentration to one with a higher solute concentration is called osmotic flow. In plants, this entails the water moving from the low concentration solute outside the cell into the cell's vacuole.[citation needed]

« Back to Glossary Index