Skip Navigation


Plant and Cell Physiology Advance Access originally published online on March 27, 2008
Plant and Cell Physiology 2008 49(5):718-729; doi:10.1093/pcp/pcn047
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
49/5/718    most recent
pcn047v1
Right arrow Alert me when this article is cited
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 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 arrowRequest Permissions
Google Scholar
Right arrow Articles by Ohya, T.
Right arrow Articles by Nakanishi, T. M.
PubMed
Right arrow PubMed Citation
Right arrow Articles by Ohya, T.
Right arrow Articles by Nakanishi, T. M.
Agricola
Right arrow Articles by Ohya, T.
Right arrow Articles by Nakanishi, T. M.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2008. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oxfordjournals.org

An Analysis of Long-Distance Water Transport in the Soybean Stem Using H215O

Tomoyuki Ohya1,*, Keitaro Tanoi2, Yousuke Hamada2, Hirotaka Okabe3, Hiroki Rai2, Junko Hojo1, Kazutoshi Suzuki1 and Tomoko M. Nakanishi2

1National Institute of Radiological Sciences, Medical Imaging, 4-9-1, Anagawa Inage-ku, Chibashi, 265-8555, Japan
2Graduate School of Agricultural and Life Sciences, The University of Tokyo, Applied Biological Chemistry, 1-1-1, Yayoi Bunkyo-ku, Tokyo, 113-8657 Japan
3Department of Applied Quantum Physics and Nuclear Engineering, Faculty of Engineering, Kyushu University, 744, Motooka, Fukuoka, 819-0395 Japan

*Corresponding author: E-mail, ohya{at}nirs.go.jp; Fax, +81-43-206-3261.


  Abstract

The lateral water movement in the intact stem of a transpiring soybean plant was analyzed quantitatively by a real-time measurement system utilizing labeled water, H215O and gamma ray detectors. A large volume of water escaping from xylem vessels during its transport was detected. The escape of water was not influenced by evaporation from the stem surface or mass flow in the sieve tubes. It was assumed that the total amount of water transported through xylem vessels was kept almost completely constant along the internode. As a result, most of the escaped water was found to re-enter the xylem vessels, i.e. water exchange occurred. The analysis of radiographs of tritiated water suggested that the self-diffusion effect of water was strong for lateral water movement, although another driving force besides thermal motion was included in the process, and that the process was also affected by the water permeability of the plasma membrane. An analysis based on a mathematical model showed that the net volume of water which escaped from xylem vessels was not dependent on the transpiration rate of the plant.

Keywords: H215O - Internode - Real-time measurement - Soybean - Water exchange - Water relations

Abbreviations: AFS, apparent free space; MRI, magnetic resonance imaging; PETIS, positron-emitting tracer imaging system; RH, relative humidity; THO, tritiated water.

(Received January 28, 2008; Accepted March 18, 2008)
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.