Aluminium speciation in the presence of wheat root cell walls: a wet chemical study

Hydrolysis of Al 3+ was performed in the presence of isolated root cell walls from a series of wheat cultivars ( Triticum aestivum L.) known to have differential tolerance to Al contamination. Aluminium speciation was dependent on the cell wall concentration. At low cell wall concentrations, significant amounts of the very toxic Al 13 species were formed. At higher cell wall concentrations, formation of the tridecamer was hindered or completely inhibited. The sensitive wheat cultivars displayed a higher affinity for aluminium than the tolerant cultivars. A possible Al tolerance mechanism based on cell wall permeability is discussed.