Wilkinson, Sally (1999) PH as a stress signal. Plant Growth Regulation, 29 (1-2). pp. 89-99. ISSN 0167-6903Full text not available from this repository.
The pH of the xylem sap of plants experiencing a range of environmental conditions can increase by over a whole pH unit. This results in an increased ABA concentration in the apoplast adjacent to the stomatal guard cells in the leaf epidermis, by reducing the ability of the mesophyll and epidermal symplast to sequester ABA away from this compartment. As a result the guard cell ABA receptors become activated and the stomata close, enabling the plant to retain water. Were it not for the low concentration of ABA ubiquitous to all land plants, the increase in the pH of the apoplast adjacent to the guard cell would induce stomatal widening, and cause excessive water loss. Not only does ABA prevent this potentially harmful phenomenon, but it also converts the pH increase to a signal which can bring about plant protection.
|Journal or Publication Title:||Plant Growth Regulation|
|Uncontrolled Keywords:||ABA - apoplast - drought - flacca - flooding - pH - stomatal guard cell - transpiration - xylem sap|
|Subjects:||Q Science > QH Natural history > QH301 Biology|
|Departments:||Faculty of Science and Technology > Lancaster Environment Centre|
|Deposited By:||Mr Richard Ingham|
|Deposited On:||29 Jul 2008 09:21|
|Last Modified:||26 Jul 2012 14:55|
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