Heat stress in plants

Heat stress in plants occurs when air temperatures rise beyond the plant’s optimal range for an extended period, disrupting vital physiological and biochemical processes. High temperatures can interfere with photosynthesis, respiration, and water uptake, leading to reduced growth, lower yields, and potential damage or death.

• Photosynthesis inhibition: Excessive heat can reduce chlorophyll function, limiting the plant’s ability to convert sunlight into energy. This weakens the plant and slows its development.
• Increased water loss: High temperatures accelerate transpiration, causing plants to lose water rapidly. If water loss exceeds the plant’s ability to absorb moisture from the soil, it may wilt or suffer dehydration.
• Cellular damage: Extreme heat can cause proteins and enzymes within plant cells to denature, leading to tissue damage and impaired metabolic functions.
• Delayed or failed reproduction: Heat stress can interfere with flower and seed development, reducing pollination success and leading to lower crop yields.
• Increased vulnerability to pests and diseases: Stressed plants often have weaker defenses, making them more susceptible to pests, fungal infections, and other diseases.
  

Plants respond to heat stress by closing their stomata to reduce water loss, producing heat-shock proteins to protect cellular structures, and sometimes altering their growth patterns. However, prolonged exposure can overwhelm these defenses, leading to irreversible damage.

To mitigate heat stress, farmers and gardeners can use strategies such as shading, mulching, proper irrigation, and selecting heat-tolerant plant varieties.