Related Experiment Video
Updated: Aug 5, 2026

High Throughput Image-Based Phenotyping for Determining Morphological and Physiological Responses to Single and Combined Stresses in Potato
Published on: June 7, 2024
Drought stress-induced changes in PSII functioning in ecologically contrasting plants: chlorophyll fluorescence study
J Hájek1, A Puhovkin2,3,4,5, J Lang6
1Department of Forest Protection and Wildlife Management, Faculty of Forestry and Wood Technology, Mendel University, Zemědělská 3, 613 00 Brno, Czech Republic.
Abstract:
Dehydration reduces photosynthetic performance in leaves and other photosynthetic organs in response to drought. This decline is linked to changes in chlorophyll fluorescence, which reflects reduced photosystem II activity and increased protective non-photochemical quenching (NPQ). This study examined NPQ dynamics during desiccation across diverse species, including lichens, mosses, conifers, crops, and C3 and C4 plants, using the method of NPQ induction and relaxation curves. Gradual dehydration from a full-hydration state (RWC 100%) to complete dryness (RWC 0%) was applied in order to compare poikilohydric and homoiohydric species. NPQmax (light period), NPQrelax (dark period end), and the initial slopes of NPQ rise (α) and decline (β) were evaluated. Relative electron transport rate curves were also assessed. Results showed the above NPQ parameters are highly sensitive to dehydration, suggesting their usefulness - along with standard maximum (FV/FM) and effective quantum yield (ΦPSII) - as early indicators of drought stress in PSII across plant groups.
Related Concept Videos
Responses to Drought and Flooding
Responses to Salt Stress
Regulation of Transpiration by Stomata
Responses to Heat and Cold Stress
Adaptations that Reduce Water Loss
