Organic acids related to differential aluminium tolerance in wheat (Triticum aestivum) cultivars

Abstract

Five cultivars of wheat (Triticum aestivum L.), which represented a range of tolerance to Al, were grown in nutrient solutions containing 0 or 2 mg Al L −1 at pH 4.5 and analyzed for organic acids by high performance liquid chromatography. Cultivars used were ‘Atlas 66’ and ‘Seneca’ (Al-tolerant), ‘Centurk’ (intermediate) and ‘Redcoat’ and ‘Scout’ (Al-sensitive). Aluminium treatment (averaged over five cultivars) decreased concentrations of c-aconitic acid and increased those of fumaric and malic acids in plant shoots. Cultivar effects (averaged over two Al levels) were significant for c-aconitic, J-aconitic, fumaric, succinic and total organic acids in plant shoots. Only two of the organic acids studied, c-aconitic and fumaric, were significantly affected by Al × cultivar interactions. Aluminium treatment (averaged over five cultivars) increased concentrations of fumaric, malic, succinic and total organic acids and decreased those of c-aconitic acid in plant roots. Cultivars (averaged over two Al treatments) differed significantly in concentrations of fumaric, malic and total organic acids in roots. Concentrations of organic acids in plant roots were not affected by Al × cultivar interactions. Differential Al tolerances among cultivars were not consistently related to differences in concentrations of organic acids in plant shoots or to changes in these concentrations under Al stress.