Stomatal closure threshold
nounPronunciation: /ˈstəʊmətəl ˈkləʊʒər ˈθreʃˌhoʊld/
The specific water potential value at which plant stomata begin to close in response to drought stress to minimize water loss through transpiration. This threshold varies among species and represents a critical physiological checkpoint for balancing photosynthesis maintenance with water conservation.
Plain English
The water stress level at which plants automatically close pores to prevent water loss.
Etymology & History
Usage
"Crop varieties with lower stomatal closure thresholds maintain photosynthesis longer during mild drought conditions."
Style guide notes: Specify 'stomatal closure threshold' for the precise water potential value; use 'stomatal response' for general response patterns.
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Related Terms
Frequently Asked Questions
How does stomatal closure threshold vary among plant species?
Drought-adapted species typically have lower thresholds, closing stomata earlier to conserve water compared to mesic species.
What is the consequence of delayed stomatal closure?
Prolonged transpiration under drought stress can lead to severe water deficit and potential permanent wilting or death.
Why Test Candidates on This?
Stomatal closure thresholds are frequently assessed in plant physiology and crop stress management curricula.
Required skill level: Mid