ISSN:
1432-2048
Keywords:
Guard cell vacuoles
;
Malic acid
;
Vacuole (swelling process)
;
Vicia (guard cells)
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00951456
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