Turgor Pressure

Definition

Turgor pressure is the pressure exerted by the fluid (usually water) inside the central vacuole of a plant cell against the cell wall. This pressure is crucial for maintaining the structural integrity and rigidity of plant cells, allowing plants to maintain their shape and stand upright. When water enters a plant cell through osmosis, it fills the vacuole, creating turgor pressure that helps support the plant’s tissues and prevents wilting.

5 Must Know Facts For Your Next Test

1. Turgor pressure is essential for plant growth, as it helps elongate cells and supports new tissue development.
2. In conditions where water is scarce, a decrease in turgor pressure can lead to wilting and reduced plant vitality.
3. Turgor pressure can be influenced by the surrounding environment, particularly in relation to soil moisture and salinity levels.
4. Cells maintain turgor pressure by balancing water intake through osmosis with the loss of water through transpiration.
5. Measuring turgor pressure can provide insights into a plant's health and its ability to adapt to environmental stresses.

Review Questions

• How does turgor pressure relate to osmosis in plant cells?
  • Turgor pressure is directly influenced by osmosis, as water moves into plant cells through a selectively permeable membrane from an area of lower solute concentration to higher solute concentration. When water enters the cell, it fills the central vacuole, increasing the internal pressure against the rigid cell wall. This process is essential for maintaining turgor pressure, which provides structural support and prevents wilting in plants.
• Discuss the consequences of decreased turgor pressure on a plant's physiological processes.
  • Decreased turgor pressure can significantly affect a plant’s physiological processes by leading to wilting and reduced growth. When turgor pressure drops, cells become less rigid, making it difficult for plants to maintain their shape and upright position. This can hinder processes such as photosynthesis and nutrient uptake, as wilting may reduce leaf surface area exposed to sunlight and decrease overall metabolic efficiency.
• Evaluate the role of turgor pressure in plant adaptations to varying environmental conditions.
  • Turgor pressure plays a crucial role in how plants adapt to different environmental conditions, such as drought or high salinity. When water is abundant, healthy turgor pressure allows plants to grow tall and robust. However, during water scarcity, plants may respond by closing stomata to conserve moisture, leading to decreased turgor pressure. Understanding these adaptations highlights how plants manage stress and maintain homeostasis in challenging environments.

Related terms

Osmosis: The movement of water molecules across a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration.

Plasmolysis: The process in which cells lose water in a hypertonic solution, causing the cell membrane to pull away from the cell wall and resulting in decreased turgor pressure.

Vacuole: A membrane-bound organelle in plant cells that stores nutrients and waste products, and plays a key role in maintaining turgor pressure.