Abstract
H+extrusion and the plasma membrane H+-ATPase activity were analyzed using barley roots exposed to ammonium. H+extrusion from roots was enhanced 4 h after the addition of 5 mol m-3ammonium to the medium. However, the stimulation of the plasma membrane H+-ATPase activity occurred at least 8 h after the addition of ammonium. Furthermore, this stimulation was found to be caused by the increase in the content of H+-ATPase proteins based on the results of immunoassay. These results indicate that H+was actively extruded to the medium through the increase in the amount of plasma membrane H+-ATPase proteins, when barley roots were exposed to ammonium for more than 8 h. Thus, it is assumed that in the long term exposure to ammonium nitrogen, ammonium-induced stimulation of the H+-ATPase activity may be important to maintain intracellular pH in root cells under the acidic conditions associated with the uptake of ammonium.
Original language | English |
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Pages (from-to) | 133-140 |
Number of pages | 8 |
Journal | Soil Science and Plant Nutrition |
Volume | 41 |
Issue number | 1 |
DOIs | |
Publication status | Published - Mar 1995 |
Externally published | Yes |
Keywords
- Ammonium
- Barley roots
- Hextrusion
- Plasma membrane
- Stimulation of H-ATPase
ASJC Scopus subject areas
- Soil Science
- Plant Science