Stomatal behavior and high relative air humidity.

 

Photo credit: Google

Tradescantia virginiana

Stomatal response characteristics of Tradescantia virginiana grown at high relative air humidity.

by Rezaei Nejad A., Van Meeteren U. (2005)

Abdolhossein Rezaei Nejad, Uulke Van Meeteren

Wageningen University, Marijkeweg 22, 6709 PG, Wageningen, the Netherlands

in Physiol. Plant. 125(3): 324-332 –DOI: 10.1111/j.1399-3054.2005.00567.x –

(CrossRef) –

http://onlinelibrary.wiley.com/doi/10.1111/j.1399-3054.2005.00567.x/abstract

Abstract

Plants produced at high relative air humidity (RH) show poor control of water loss after transferring to low RH, a phenomenon which is thought to be due to their stomatal behaviour.

The stomatal anatomy and responses of moderate (55%) and high (90%) RH grown Tradescantia virginiana plants to treatments that normally induce stomatal closure, i.e. desiccation, abscisic acid (ABA) application and exposure to darkness were studied using attached or detached young, fully expanded leaves.

Compared with plants grown at moderate RH the transpiration rate, stomatal conductance and aperture of high RH grown plants measured at the same condition (40% RH) were, respectively, 112, 139 and 132% in light and 141, 188 and 370% in darkness.

Besides the differences in stomatal size (guard cell length was 56.7 and 73.3 µm for moderate and high RH grown plants, respectively), there was a clear difference in stomatal behaviour.

The stomata responded to desiccation, ABA and darkness in both moderate and high RH grown plants, but the high variability of stomatal closure in high RH grown plants was striking. Some stomata developed at high RH closed in response to darkness or to a decrease in relative water content to the same extent as did stomata from moderate RH grown plants, whereas others closed only partly or did not close at all.

Evidently, some as yet unidentified physiological or anatomical changes during development disrupt the normal functioning of some stomata in leaves grown at high RH. The failure of some stomata to close fully in response to ABA suggests that ABA deficiency was not responsible for the lack of stomatal closure in response to desiccation.

Advertisements

Published by

Willem Van Cotthem

Honorary Professor of Botany, University of Ghent (Belgium). Scientific Consultant for Desertification and Sustainable Development.

Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s