Planta

, Volume 161, Issue 1, pp 27–31

Determination of malate levels during the swelling of vacuoles isolated from guard-cell protoplasts

  • H. Schnabl
  • C. Kottmeier
Article

DOI: 10.1007/BF00951456

Cite this article as:
Schnabl, H. & Kottmeier, C. Planta (1984) 161: 27. doi:10.1007/BF00951456

Abstract

A method for the preparation of vacuoles from guard cells ofVicia faba L. is described. Vacuoles were released from guard-cell protoplasts by osmotic shock and purified on a Ficoll gradient. Contamination of the vacuoles was examined by assaying marker enzymes, such as fumarase, glucose-6-phosphate dehydrogenase, phosphofructokinase, acid phosphatase and mannosidase. Potassium ions in the incubation medium caused increases in the volume of the vacuoles by a factor of about 2.6, while the malate level remained unchanged. In contrast, malate synthesis was stimulated during the swelling phase when complete guard-cell protoplasts were exposed to K+. The possible role of K+ as an efficient osmotic effector is discussed.

Key words

Guard cell vacuolesMalic acidVacuole (swelling process)Vicia (guard cells)

Abbreviations

DEAE

diethylaminoethyl

GCP

guard-cell protoplast(s)

GCV

guard-cell vacuoles(s)

MCP

mesophyll cell protoplast(s)

MCV

mesophyll cell vacuole(s)

Copyright information

© Springer-Verlag 1984

Authors and Affiliations

  • H. Schnabl
    • 1
  • C. Kottmeier
    • 1
  1. 1.Institut für Botanik der Technischen UniversitätMünchen 2Germany