Related Experiment Video
Updated: Aug 8, 2026
04:32
An Induction System for Clustered Stomata by Sugar Solution Immersion Treatment in Arabidopsis thaliana Seedlings
Published on: February 15, 2019
Stomatal Response to Environment with Sesamum indicum. L
1Department of Plant Science, University of California, Riverside, California 92502.
Plant Physiology
|March 1, 1975
Summary
Increasing humidity gradients raise leaf resistance in sesame plants by reducing stomatal aperture, impacting photosynthesis. This effect is temperature-dependent and influenced by internal carbon dioxide levels.
Area of Science:
- Plant physiology
- Environmental stress responses in plants
- Photosynthesis and respiration in plants
Background:
- Plant leaf resistance is crucial for regulating water loss and carbon dioxide uptake.
- Environmental factors like humidity gradients and temperature significantly influence plant physiological processes.
- Understanding stomatal responses to humidity is key to predicting plant productivity under varying environmental conditions.
Purpose of the Study:
- To investigate the impact of humidity gradients on leaf resistance in Sesamum indicum L.
- To determine the role of stomatal aperture versus mesophyll resistance in response to humidity changes.
- To assess the influence of internal carbon dioxide concentrations and leaf temperature on stomatal behavior.
Main Methods:
- Measurements of leaf resistance in Sesamum indicum L. under controlled temperature and humidity conditions.
- Calculation of internal carbon dioxide concentrations within the leaf.
- Analysis of the relationship between humidity gradients, stomatal aperture, mesophyll resistance, and photosynthetic rates.
Main Results:
- Leaf resistance significantly increased with larger humidity gradients between the leaf and air, particularly at moderate temperatures.
- Mesophyll resistance remained constant, indicating that stomatal aperture was the primary factor affected by humidity gradients.
- Stomatal response to humidity was absent at high leaf temperatures, and low internal carbon dioxide levels partially reduced, but did not eliminate, the humidity gradient's effect on resistance.
Conclusions:
- Increased humidity gradients lead to reduced stomatal aperture and increased leaf resistance, primarily affecting water regulation.
- High leaf temperatures can negate the stomatal response to humidity, while internal carbon dioxide levels modulate this response.
- These findings suggest that significant humidity gradients may contribute to midday stomatal closure and reduced photosynthesis in plants.
More Related Videos
Related Concept Videos
02:02Responses to Salt Stress
Salt stress—which can be triggered by high salt concentrations in a plant’s environment—can significantly affect plant growth and crop production by influencing photosynthesis and the absorption of water and nutrients.
02:45Responses to Heat and Cold Stress
Every organism has an optimum temperature range within which healthy growth and physiological functioning can occur. At the ends of this range, there will be a minimum and maximum temperature that interrupt biological processes.
02:04Regulation of Transpiration by Stomata
During photosynthesis, plants acquire the necessary carbon dioxide and release the produced oxygen back into the atmosphere. Openings in the epidermis of plant leaves is the site of this exchange of gasses. A single opening is called a stoma—derived from the Greek word for “mouth.” Stomata open and close in response to a variety of environmental cues.
02:41Responses to Drought and Flooding
Water plays a significant role in the life cycle of plants. However, insufficient or excess of water can be detrimental and pose a serious threat to plants.
01:57Adaptations that Reduce Water Loss
Though evaporation from plant leaves drives transpiration, it also results in loss of water. Because water is critical for photosynthetic reactions and other cellular processes, evolutionary pressures on plants in different environments have driven the acquisition of adaptations that reduce water loss.
01:25Cell Signaling in Plants
Plant cells communicate to coordinate their cycle of growth, flowering and fruiting, and activities in roots, shoots, and leaves in response to the changing environmental conditions. Plant signaling is distinct from animal signaling. Plants primarily utilize enzyme-linked receptors, whereas the largest class of cell-surface receptors in animals are G-protein coupled receptors (GPCRs). Unlike animals, receptor tyrosine kinases are rare in plants. Instead, plants have a diverse class of...