The effects of short and long term aluminium treatment on potassium fluxes in roots of an aluminium sensitive cultivar of barley
1991
Nichol, B.E. | Oliveira, L. | Glass, A.D.M. | Siddiqi, M.Y.
The object of this study was to determine the impact of short (10 minutes) and long term (5 day) treatments with aluminium ions on the influx and efflux of K-ions ((86)Rb) in Hordeum vulgare var. Kearney. The speed at which inhibition occurred and the persistence of any inhibition in the absence of aluminium was also investigated. The influx of K-ions ((86)Rb) was inhibited by 41% when treated for 5 days with 5 micromolar Al at pH 4.2. Plants treated with 50 micromolar Al for 30 seconds showed a significant reduction in K-ion influx. The Al-induced inhibition of K-ion influx was found to be reversible since plants treated for 10 minutes with 50 micromolar Al returned to control influx levels when transferred to Al-free medium. The K-ion inhibition from long term (5 days) treatment with 5 micromolar Al was also reversible since K-ion influx returned immediately to control levels when Al was not present. The efflux half times for K-ions from plants treated with 5 micromolar Al for 5 days was found to be similar to controls. When K-ion influx was measured with increasing potassium in solution, it was found that K-ions appear to competitively reduce the impact of Al-ions. These results are discussed in light of the current ideas on how aluminium inhibits ion transport systems.
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