Planta

, Volume 201, Issue 2, pp 195–201

Symplasmic connections between sieve element and companion cell in the stem phloem ofVicia faba L. have a molecular exclusion limit of at least 10 kDa

Authors

    • Transport Physiology Research Group, Department of Plant Ecology and Evolutionary BiologyUtrecht University
  • Aart J. E. van Bel
    • Botanisches Institut 1Justus-Liebig University
Article

DOI: 10.1007/BF01007704

Cite this article as:
Kempers, R. & van Bel, A.J.E. Planta (1997) 201: 195. doi:10.1007/BF01007704

Abstract

High-molecular-weight fluorochromes were intracellularly injected into a sieve element of the fascicular stem phloem ofVicia faba L., using a modified membrane-potential-recording pressure probe. After stabilization of the membrane potential following microelectrode impalement, either LYCH (Lucifer Yellow CH), 4.4-kDa FITC-dextran (fluoresceinisothiocyanate-dextran) conjugate, or 3-kDa, 10-kDa or 40-kDa LYCH-dextran conjugate was microinjected into the sieve element. Longitudinal fluorochrome movement across the sieve plates and lateral displacement to the companion cells was detected with all the probes except the 40-kDa conjugate. This indicates that the molecular exclusion limit of the pore/plasmodesma units between a sieve element and a companion cell in the fascicular stem phloem ofVicia faba lies between 10 kDa and 40 kDa.

Key words

Fluorescent dextranIntracellular microinjectionMolecular exclusion limitPore/plasmodesma unitSieve element/companion cell complexVicia

Abbreviations

FITC

fluoresceinisothiocyanate

LYCH

Lucifer Yellow CH

MEL

molecular exclusion limit

PPU

pore/plasmodesma unit

SE/CC-complex

sieve element/companion cell complex

Copyright information

© Springer-Verlag 1997