Ammonium-stimulated potassium release from Lemna minor L. grown on a medium containing nitrate as N-source

Beck, Thomas; Feller, Urs (1991). Ammonium-stimulated potassium release from Lemna minor L. grown on a medium containing nitrate as N-source. Aquatic botany, 39(3-4), pp. 255-266. Elsevier 10.1016/0304-3770(91)90003-N

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Net K-efflux from duckweed (Lemna minor L.) was initiated by the addition of NH4Cl to nutrient medium with NO3 as the only nitrogen source. Other NH4-salts (sulfate or nitrate) were also effective, while LiCl, NaCl, RbCl or CsCl caused no major K-release under the same conditions. Sodium, Rb and Cs ions lowered the net K-uptake observed in controls with no effector added, while in presence of Li ions the absorption of K was stimulated. These results provide putative evidence that K-release into the medium is specific for NH4 addition and not a general effect of monovalent cations. The level and the time course for K-efflux depended on the NH4 concentration added (1-30 mM), but the pH in the medium (3.7, 6.8 or 7.9) caused only minor effects. These findings suggest that the K-release was initiated by NH4 ions rather than by NH3 passing through the plasmalemma. Magnesium ions were released in a similar manner after NH4 additions, but only to about 10% of the rate observed for K. No clear NH4-stimulated net efflux was observed for Na and Ca ions. Potassium-release was not detectable after the addition of high NH4 concentrations to duckweed grown on NH4-medium. The release of K was apparently associated with the transition from NO3 to NH4 utilization and might be linked directly or indirectly to the high initial absorption rate for NH4.

Item Type:

Journal Article (Original Article)

Division/Institute:

04 Faculty of Medicine > Medical Education > Institute of General Practice and Primary Care (BIHAM)
08 Faculty of Science > Department of Biology > Institute of Plant Sciences (IPS) > Plant nutrition [discontinued]
08 Faculty of Science > Department of Biology > Institute of Plant Sciences (IPS)

UniBE Contributor:

Feller, Urs

Subjects:

600 Technology > 610 Medicine & health
300 Social sciences, sociology & anthropology > 360 Social problems & social services
500 Science > 580 Plants (Botany)

ISSN:

0304-3770

Publisher:

Elsevier

Language:

English

Submitter:

Peter Alfred von Ballmoos-Haas

Date Deposited:

24 Mar 2017 14:40

Last Modified:

24 Mar 2017 14:40

Publisher DOI:

10.1016/0304-3770(91)90003-N

BORIS DOI:

10.7892/boris.91908

URI:

https://boris.unibe.ch/id/eprint/91908

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