Drought resistance

Definition

Drought resistance refers to the ability of plants to survive and thrive in conditions with limited water availability. This trait enables them to withstand periods of drought by employing various physiological, structural, and biochemical adaptations. These adaptations are crucial for plant survival in arid environments, influencing their distribution and ecological roles.

5 Must Know Facts For Your Next Test

1. Plants that exhibit drought resistance often have deep root systems that allow them to access moisture from deeper soil layers.
2. Some drought-resistant plants can close their stomata to reduce water loss during dry periods, helping conserve moisture.
3. Certain plants accumulate osmoprotectants like proline and glycine betaine to maintain cell turgor and function under drought conditions.
4. Drought resistance can also involve morphological changes, such as smaller leaves or thicker cuticles, which reduce transpiration.
5. The genetic basis of drought resistance is an area of active research, aiming to identify genes that could be introduced into crops for improved resilience.

Review Questions

• How do physiological adaptations contribute to a plant's drought resistance?
  • Physiological adaptations such as stomatal closure, osmotic adjustment, and increased root depth play critical roles in enabling plants to resist drought conditions. By closing their stomata, plants reduce water loss through transpiration, which is essential during dry periods. Additionally, osmotic adjustment allows cells to maintain turgor pressure even when water availability is low, while deeper roots help access moisture not available to shallow-rooted species.
• Discuss the role of drought resistance in the ecological distribution of gymnosperms.
  • Drought resistance is a key factor in determining where gymnosperms can thrive, particularly in regions characterized by low water availability. Many gymnosperms have evolved features such as needle-like leaves and thick bark, which reduce water loss and protect them from desiccation. As a result, these adaptations allow gymnosperms to occupy habitats that are unsuitable for less drought-resistant plants, contributing to their success in diverse ecosystems.
• Evaluate the significance of drought resistance in agricultural practices and food security.
  • Drought resistance plays a crucial role in agricultural practices as climate change increases the frequency and severity of droughts worldwide. Developing crops that exhibit enhanced drought resistance can lead to more stable yields even under adverse conditions. This advancement is vital for food security, particularly in regions that rely heavily on agriculture for sustenance. By focusing on breeding programs that target drought-resistant traits, we can mitigate the impacts of water scarcity on crop production.

Related terms

Xerophyte: A plant that is adapted to survive in an environment with very little water, often characterized by features such as thick cuticles and deep root systems.

Water Use Efficiency: A measure of how well a plant utilizes water for growth and photosynthesis, often expressed as the amount of biomass produced per unit of water used.

Drought Stress: The physiological condition in which a plant experiences a shortage of water, leading to negative impacts on growth, development, and overall health.