Skip Navigation


JXB Advance Access originally published online on July 2, 2004
Journal of Experimental Botany 2004 55(403):1751-1760; doi:10.1093/jxb/erh215
This Article
Right arrow Full Text Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
55/403/1751    most recent
erh215v1
Right arrow E-letters: Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when E-letters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (12)
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Melkonian, J.
Right arrow Articles by Setter, T. L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Melkonian, J.
Right arrow Articles by Setter, T. L.
Agricola
Right arrow Articles by Melkonian, J.
Right arrow Articles by Setter, T. L.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Journal of Experimental Botany, Vol. 55, No. 403, © Society for Experimental Biology 2004; all rights reserved

RESEARCH PAPER

Chilling responses of maize (Zea mays L.) seedlings: root hydraulic conductance, abscisic acid, and stomatal conductance

Jeffrey Melkonian*, Long-Xi Yu and Tim L. Setter

Department of Crop and Soil Sciences, Bradfield Hall, Cornell University, Ithaca, New York 14853-1901, USA

* To whom correspondence should be addressed. Fax: +1 607 255 2106. E-mail: jjm11{at}cornell.edu

Maize seedling water relations and abscisic acid (ABA) levels were measured over 24 h of root chilling (5.5 °C). At 2.5 h into chilling, leaf ABA levels increased by 40x and stomatal conductance (gs) decreased to 20% compared with prechill levels. Despite a rapid gs response to root chilling, leaf water potential ({Psi}L) of chilled seedlings decreased to –2.2 MPa resulting in a complete loss of turgor potential ({psi}p). Ineffective gs control early in chilling resulted from decreased root hydraulic conductance (Lr) due to increased water viscosity and factor(s) intrinsic to the roots. After 24 h chilling, {Psi}L and {psi}p of chilled seedlings recovered to control levels due to stomatal control of transpiration and increased Lr. The impact of the temporal changes in gs and Lr on maize seedling water relations during chilling was analysed using a simple, quantitative hydraulic model. It was determined that gs is critical to stabilizing {Psi}L at non-lethal levels in chilled seedlings at 2.5 h and 24 h chilling. However, there was also a significant contribution due to increased Lr at 24 h chilling so that {psi}p increased to control levels. As a first step in determining the factor(s) responsible for the increase in Lr, cDNA microarrays were used to quantify the transcript levels of eight aquaporins obtained from mature root tissue at 24 h chilling. None of these were significantly up-regulated, suggesting that the increase in Lr was not due to regulation of these aquaporins at the transcriptional level.

Key words: Abscisic acid, aquaporin, leaf turgor potential, leaf water potential, model, recovery, steady-state, stomatal conductance, up-regulation


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.