Plant Stress and Water Stress

Physiology of Plant Stress and Water Stress Effects

• Stress is defined as an external factor that negatively affects plant survival, crop yield, biomass accumulation, and primary processes related to growth.
• Stress tolerance is the plant's ability to cope with an unfavorable environment, and it varies among plants.
• Acclimation is when the plant's tolerance increases due to prior stress exposure, while adaptation refers to a genetically determined level of resistance.
• Plants are frequently exposed to stress under natural and agricultural conditions, and some environmental factors may take days, weeks, or even months to become stressful.
• Water stress results in stomatal closure, which happens when guard cells directly lose water to the atmosphere or have a lowered solute content.
• Water-stressed plants have smaller leaves due to cell shrinkage, cell wall relaxation, and senescence, which reduces water loss by transpiration.
• Root extension is enhanced in water-stressed plants due to a smaller leaf area, allowing more assimilates to be distributed to the root system, supporting deeper soil penetration.
• Photosynthesis is decreased during water stress due to stomatal closure and desiccation of mesophyll cells, which negatively affects metabolism.
• Transpiration is crucial for cooling leaf surfaces and the atmosphere, and less transpiration during water stress leads to increased leaf temperatures.
• Water uptake and movement are reduced during water stress due to water molecules clinging more tightly to soil particles, root shrinkage, damage to root hairs, and suberin covering mature roots.
• Large xylem vessels cavitate during water stress, but smaller vessels and tracheids can continue water transport.
• Water stress during reproduction is more sensitive, as assimilates are directed to the fruit rather than the roots.

Test your knowledge on the physiology of plant stress and water stress effects with this informative quiz. Explore the various external factors that negatively affect plant survival, and learn about stress tolerance, acclimation, and adaptation in plants. Discover how water stress impacts plant growth, including the closure of stomata, decreased photosynthesis, and reduced water uptake and movement. Explore the effects of stress on reproduction and the importance of transpiration in maintaining leaf temperature. Challenge yourself and expand your understanding of plant stress with this educational