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A rate equation model of stomatal responses to vapour pressure deficit and drought

Eamus, Derek and Shanahan, Stephen T. (2002). A rate equation model of stomatal responses to vapour pressure deficit and drought. BMC Ecology,2:8.

Document type: Journal Article
Citation counts: Scopus Citation Count Cited 20 times in Scopus Article | Citations

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Title A rate equation model of stomatal responses to vapour pressure deficit and drought
Author Eamus, Derek
Shanahan, Stephen T.
Journal Name BMC Ecology
Publication Date 2002
Volume Number 2
ISSN 1472-6785   (check CDU catalogue open catalogue search in new window)
Scopus ID 2-s2.0-2942704088
Start Page 8
Total Pages 14
Place of Publication London, United Kingdom
Publisher BioMed Central Ltd
HERDC Category C1 - Journal Article (DEST)
Abstract Background Stomata respond to vapour pressure deficit (D) – when D increases, stomata begin to close. Closure is the result of a decline in guard cell turgor, but the link between D and turgor is poorly understood. We describe a model for stomatal responses to increasing D based upon cellular water relations. The model also incorporates impacts of increasing levels of water stress upon stomatal responses to increasing D. Results The model successfully mimics the three phases of stomatal responses to D and also reproduces the impact of increasing plant water deficit upon stomatal responses to increasing D. As water stress developed, stomata regulated transpiration at ever decreasing values of D. Thus, stomatal sensitivity to D increased with increasing water stress. Predictions from the model concerning the impact of changes in cuticular transpiration upon stomatal responses to increasing D are shown to conform to experimental data. Sensitivity analyses of stomatal responses to various parameters of the model show that leaf thickness, the fraction of leaf volume that is air-space, and the fraction of mesophyll cell wall in contact with air have little impact upon behaviour of the model. In contrast, changes in cuticular conductance and membrane hydraulic conductivity have significant impacts upon model behaviour. Conclusion Cuticular transpiration is an important feature of stomatal responses to D and is the cause of the 3 phase response to D. Feed-forward behaviour of stomata does not explain stomatal responses to D as feedback, involving water loss from guard cells, can explain these responses.
DOI http://dx.doi.org/10.1186/1472-6785-2-8   (check subscription with CDU E-Gateway service for CDU Staff and Students  check subscription with CDU E-Gateway in new window)
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URL http://www.biomedcentral.com/1472-6785
 
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