All Physics Faculty Publications

Title

Stomatal Responses to Humidity in Isolated Epidermes

Document Type

Article

Journal/Book Title/Conference

Plant, Cell, & Environment

Volume

31

Issue

9

Publication Date

9-2008

First Page

1290

Last Page

1298

DOI

10.1111/j.1365-3040.2008.01844.x

Abstract

The ability of guard cells to hydrate and dehydrate from the surrounding air was investigated using isolated epidermes of Tradescantia pallida and Vicia faba. Stomata were found to respond to the water vapour pressure on the outside and inside of the epidermis, but the response was more sensitive to the inside vapour pressure, and occurred in the presence or absence of living, turgid epidermal cells. Experiments using helium–oxygen air showed that guard cells hydrated and dehydrated entirely from water vapour, suggesting that there was no significant transfer of water from the epidermal tissue to the guard cells. The stomatal aperture achieved at any given vapour pressure was shown to be consistent with water potential equilibrium between the guard cells and the air near the bottom of the stomatal pore, and water vapour exchange through the external cuticle appeared to be unimportant for the responses. Although stomatal responses to humidity in isolated epidermes are the result of water potential equilibrium between the guard cells and the air near the bottom of the stomatal pore, stomatal responses to humidity in leaves are unlikely to be the result of a similar equilibrium.

Comments

Published by Wiley-Blackwell in Plant, Cell, & Environment. Publisher PDF available through link above. Publisher requires a subscription to access article.

http://onlinelibrary.wiley.com/doi/10.1111/j.1365-3040.2008.01844.x/abstract