Protoplasma

, Volume 209, Issue 1, pp 126–131

Dynamic studies of phloem and xylein flow in fully differentiated plants by fast nuclear-magnetic-resonance microimaging

  • M. Rokitta
  • A. D. Peuke
  • U. Zimmermann
  • A. Haase
Rapid Communication

DOI: 10.1007/BF01415708

Cite this article as:
Rokitta, M., Peuke, A.D., Zimmermann, U. et al. Protoplasma (1999) 209: 126. doi:10.1007/BF01415708

Summary

A fast nuclear-magnetic-resonance imaging method was developed in order to measure simultaneously and quantitatively the water flow velocities in the xylem and the phloem of intact and transpiring plants. Due to technical improvements a temporal resolution of 7 min could be reached and flow measurements could be performed over a time course of 12–30 h. The novel method was applied to the hypocotyl of 35– to 40-day-old, leafy plants ofRicinus communis which were subjected to different light-dark regimes. The results showed that the xylem flow velocities and the xylem volume flow responded immediately to light on-off changes. Upon illumination the flow velocity and the volume flow increased as expected in respect to literature. In contrast, the phloem flow velocity did not change in response to the light-dark regimes. Interestingly, though, the volume flow in the phloem increased during darkness. These findings can be explained by assuming that the conducting area of the phloem becomes enlarged during the dark period due to opening of sieve pores.

Keywords

Phloem flowXylem flowWater transportNuclearmagnetic-resonance imagingRicinus communis L

Copyright information

© Springer-Verlag 1999

Authors and Affiliations

  • M. Rokitta
    • 1
  • A. D. Peuke
    • 2
  • U. Zimmermann
    • 3
  • A. Haase
    • 1
  1. 1.Physikalisches Institut, EP 5Universität WürzburgWürzburgFederal Republic of Germany
  2. 2.Julius-von-Sachs-Institut für BiowissenschaftenUniversität WürzburgWürzburg
  3. 3.Lehrstuhl für Biotechnologie, BiozentrumUniversität WürzburgWürzburg