An analysis of long-distance water transport in the soybean stem using H215O

Tomoyuki Ohya, Keitaro Tanoi, Yousuke Hamada, Hirotaka Okabe, Hiroki Rai, Junko Hojo, Kazutoshi Suzuki, Tomoko M. Nakanishi

Research output: Contribution to journalArticle

14 Citations (Scopus)

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.

Original languageEnglish
Pages (from-to)718-729
Number of pages12
JournalPlant and Cell Physiology
Volume49
Issue number5
DOIs
Publication statusPublished - May 1 2008

All Science Journal Classification (ASJC) codes

  • Physiology
  • Plant Science
  • Cell Biology

Fingerprint Dive into the research topics of 'An analysis of long-distance water transport in the soybean stem using H<sub>2</sub><sup>15</sup>O'. Together they form a unique fingerprint.

  • Cite this

    Ohya, T., Tanoi, K., Hamada, Y., Okabe, H., Rai, H., Hojo, J., Suzuki, K., & Nakanishi, T. M. (2008). An analysis of long-distance water transport in the soybean stem using H215O. Plant and Cell Physiology, 49(5), 718-729. https://doi.org/10.1093/pcp/pcn047