ALUMINUM SPECIATION IN THE PRESENCE OF WHEAT ROOT CELL-WALLS - A WET CHEMICAL STUDY

Hydrolysis of Al3+ was performed in the presence of isolated root cell walls from a series of wheat cultivars (Triticum aestivum L.) known t o have differential tolerance to Al contamination, Aluminium speciatio n was dependent on the cell wall concentration. At low cell wall conce ntrations, significant amounts of the very toxic Al-13 species were fo rmed. At higher cell wall concentrations, formation of the tridecamer was hindered or completely inhibited. The sensitive wheat cultivars di splayed a higher affinity for aluminium than the tolerant cultivars. A possible Al tolerance mechanism based on cell wall permeability is di scussed.