The uptake and localization of aluminium in root tissues as well as th
e effect of Al-stress on intracellular concentrations of phosphate and
potassium were analysed by X-ray microanalysis (EDXA). Al is predomin
antly localized in the cell walls of peripheral cells, and is only ver
y slowly translocated to more central tissues. The plasma membrane is
a very effective barrier against Al-influx into the cells, so that 24
h after onset of Al-treatment no intracellular detection of Al was pos
sible. Furthermore, during a 10-day period of Al-treatment, Al was not
accumulated in the nuclei of meristematic root tissues. Although in t
he cell wall Al is partially precipitated as aluminium phosphate, this
causes no P-depriviation of root cells. Likewise, the K-uptake and tr
ansport into the stele is not affected by Al-stress.