Rapid low temperature-induced stomatal closure and calcium

Photo credit: Google

Commelina communis

Rapid low temperature-induced stomatal closure occurs in cold-tolerant Commelina communis L. leaves but not in cold-sensitive Nicotiana rustica L. leaves, via a mechanism that involves apoplasic calcium but not abscisic acid.

by Wilkinson S., Clephan A. L., Davies W. J. (2001)

  1. Sally Wilkinson
  2. Alison Lee Clephan
  3. William John Davies
     
     

Biological Sciences Department, Institute of Environmental and Natural Sciences, Lancaster University, Bailrigg, Lancaster LA1 4YQ, United Kingdom

in Plant Physiology 126: 15661578. – doi: http:/​/​dx.​doi.​org/​10.​1104/​pp.​126.​4.​1566 – 

CrossRef |PubMed |CAS |-

http://www.plantphysiol.org/content/126/4/1566

nicotiana-rustica=wild-tobacco
Wild Tobacco – Nicotiana rustica – http://www.naturalmedicinalherbs.net/pictures/wendys/nicotiana-rustica=wild-tobacco.jpg

Abstract

Commelina communis stomata closed within 1 h of transferring intact plants from 27°C to 7°C, whereas tobacco (Nicotiana rustica) stomata did not until the leaves wilted.

Abscisic acid (ABA) did not mediate cold-induced C. communis stomatal closure: At low temperatures, bulk leaf ABA did not increase; ABA did not preferentially accumulate in the epidermis; its flux into detached leaves was lower; its release from isolated epidermis was not greater; and stomata in epidermal strips were less sensitive to exogenous ABA.

Stomata of both species in epidermal strips on large volumes of cold KCl failed to close unless calcium was supplied. Therefore, the following cannot be triggers for cold-induced stomatal closure in C. communis: direct effects of temperature on guard or epidermal cells, long-distance signals, and effects of temperature on photosynthesis. Low temperature increased stomatal sensitivity to external CaCl2 by 50% in C. communis but only by 20% in tobacco. C. communis stomata were 300- to 1,000-fold more sensitive to calcium at low temperature than tobacco stomata, but tobacco epidermis only released 13.6-fold more calcium into bathing solutions than C. communis.

Stomata in C. communis epidermis incubated on ever-decreasing volumes of cold calcium-free KCl closed on the lowest volume (0.2 cm3) because the epidermal apoplast contained enough calcium to mediate closure if this was not over diluted.

We propose that the basis of cold-induced stomatal closure exhibited by intact C. communis leaves is increased apoplastic calcium uptake by guard cells. Such responses do not occur in chill-sensitive tobacco leaves.

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