Aluminium Sensitivity and Tolerance in Model and Elite Wheat (Triticum eastivum L) Varieties

Yang Li¹, Guangxiao Yang¹, Liting Luo¹, Tao Ke¹, Jinrui Zhang¹, Kexiu L² and Guangyuan He^1*

Abstract： Three wheat varieties of Atlas66 (Al-tolerant genotype), EM12 (a major elite cultivar in China) and Scout66 (Al-sensitive genotype) were used to investigate their potential mechanisms of Al toxicity. Al concentrations of 50, 75, 100 mmol∙l^-1 were used and the inhibition on root elongation between Scout66 and EM12 is significantly higher than that of Al-tolerant Atlas66, which is negative correlated to the Al absorption in root apices. Organic acids secretion was checked 24 h after Al stress and only malate was detected in Atlas66, but none of the organic acids were detected in the others, suggesting that secretion of malate in root is a major mechanism of Al resistance in Al-tolerant wheat genotype. The root cell ultrastructure showed less damage in Atlas66 than that in Scout66 and EM12 under Al stress by transmission electron microscopy (TEM) technique. Tissue culture was carried out and the callus induction frequencies were all decreased on the media containing Al. The decrease of callus induction frequencies was less in Atlas66 than that in the others. It is concluded that Al damages the cell ultrastructure, resulting in the inhibition of acids secretion and cell division, which implies that the damage of cell ultrastructure is probably the key factor in Al inhibition of root growth.

Keywords: Al-sensitivity and tolerance, cell ultrastructure, malic acid, root apex, wheat

Link: http://akademiai.com/doi/abs/10.1556/CRC.36.2008.2.6

Doi:10.1556/CRC.36.2008.2.6