Turgor pressure

Definition

Turgor pressure is the internal pressure exerted by the fluid (typically water) inside a plant cell against its cell wall, which helps maintain the cell's shape and rigidity. This pressure plays a crucial role in keeping plants upright and is a result of the osmotic movement of water into the cell, causing it to swell. When turgor pressure is adequate, it ensures that the plant remains turgid, supporting various physiological processes.

5 Must Know Facts For Your Next Test

1. Turgor pressure is critical for maintaining plant structure and preventing wilting, as it helps keep cells firm and upright.
2. When turgor pressure decreases due to water loss, plants can become flaccid, leading to wilting and reduced photosynthesis.
3. Turgor pressure is generated when water enters the vacuole of a plant cell through osmosis, pushing against the rigid cell wall.
4. In addition to supporting plant cells, turgor pressure also facilitates the growth of new cells by driving expansion during cell division.
5. Turgor pressure can be affected by environmental factors like soil moisture and temperature, influencing overall plant health and productivity.

Review Questions

• How does turgor pressure affect the overall health and growth of a plant?
  • Turgor pressure is essential for maintaining the structural integrity of plant cells and ensuring that they remain turgid, which supports upright growth. When turgor pressure is sufficient, it enables plants to absorb sunlight effectively for photosynthesis and promotes nutrient transport within the plant. A decrease in turgor pressure can lead to wilting, which negatively impacts a plant's ability to grow and thrive.
• Discuss the relationship between osmosis and turgor pressure in plant cells.
  • Osmosis directly influences turgor pressure as water moves into plant cells through their semipermeable membranes. This influx of water occurs when the surrounding environment has a lower solute concentration than the inside of the cell, creating a hypotonic solution. As water enters, it fills the vacuole and exerts pressure against the cell wall, leading to increased turgor pressure that helps maintain cell shape and rigidity.
• Evaluate how environmental conditions can impact turgor pressure in plants and the implications for their survival.
  • Environmental conditions such as soil moisture levels and temperature fluctuations significantly affect turgor pressure in plants. In dry conditions or drought, limited water availability reduces turgor pressure, leading to wilting and decreased physiological functions like photosynthesis. This stress can hinder plant growth and reproduction, making them more vulnerable to diseases or pests. Conversely, optimal water availability promotes healthy turgor pressure, enhancing overall plant vitality and resilience in varying environmental contexts.

Related terms

Osmosis:

The passive movement of water molecules across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration.

Cell wall: A rigid outer layer that provides structure and protection to plant cells, allowing them to withstand turgor pressure.

Plasmolysis: The process in which a plant cell loses water in a hypertonic solution, causing the cell membrane to pull away from the cell wall due to decreased turgor pressure.