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 cell shape and rigidity, enabling plants to stand upright and resist wilting. It also plays a significant role in nutrient transport and overall plant health by influencing growth patterns and cell expansion.

5 Must Know Facts For Your Next Test

1. Turgor pressure is vital for keeping plant cells firm and helps prevent wilting when water is available.
2. When turgor pressure is high, it can support structures like leaves and flowers, making them more effective at photosynthesis.
3. Turgor pressure is influenced by osmosis, where water moves into the vacuole, increasing the internal pressure against the cell wall.
4. Plants adjust turgor pressure to respond to environmental changes, helping them cope with drought or excessive water.
5. Disruption of turgor pressure can lead to problems like cell collapse or compromised plant growth.

Review Questions

• How does turgor pressure contribute to the structural integrity of plant cells?
  • Turgor pressure contributes to the structural integrity of plant cells by exerting pressure from the central vacuole against the cell wall. This pressure keeps the cell firm and maintains its shape, preventing wilting. When a plant has adequate water, high turgor pressure supports upright growth and allows leaves to expand fully, maximizing their surface area for photosynthesis.
• What are the consequences of low turgor pressure on plant health and growth?
  • Low turgor pressure can lead to wilting, loss of cell shape, and reduced overall plant vigor. When turgor pressure drops, cells may experience plasmolysis, where they shrink away from the cell wall. This condition can limit nutrient transport and hinder growth processes, making the plant more susceptible to stressors like drought or disease.
• Evaluate the relationship between turgor pressure and plant adaptation to varying environmental conditions.
  • Turgor pressure plays a crucial role in how plants adapt to varying environmental conditions by regulating their water content and maintaining cellular functions. During droughts, plants may close stomata to reduce water loss, which can lead to decreased turgor pressure. However, some plants have developed mechanisms like deeper roots or thicker cuticles to retain water and sustain turgor pressure even under stress. This adaptability ensures that they can survive fluctuating availability of water while continuing essential physiological processes.

Related terms

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

Cell Wall: The rigid outer layer of plant cells composed mainly of cellulose, which provides structural support and protection while working with turgor pressure to maintain cell shape.

Plasmolysis: The process where plant cells lose water in a hypertonic solution, leading to a decrease in turgor pressure and causing the cell membrane to pull away from the cell wall.