Combined effects of Mg and Ca supply on alleviation of Al toxicity in wheat plants

A Bangladeshi wheat (Triticum aestivum) cultivar, Kalyansona, was exposed to 100 J.µ Al with varying concentrations of Ca (250, 500, 2,500 J.µM) and Mg (103, 1,029, 4,115 J.µ) in the nutrient solution for 14 d. Exposure to Al along with low concentrations of both Ca and Mg caused severe damage to the root apex. Under AI-stressed conditions, an increased supply of Mg from 103 to 1,029 J.µ enhanced the root length by 44, 22, and 3% at 250, 500, and 2,500 J.µ Ca, respectively. Root growth at 2,500 J.µ Ca was not affected by additional Mg concentration. Again, an increased supply of Mg from 103 to 4,115 J.µ enhanced the root length by 56% at 500 J.µ Ca. Under the Al-stressed conditions, the increase in the root length was correlated with the decrease in the Al content in roots. Our results suggest that Mg alleviates Al toxicity efficiently in the presence of Ca at a low level in the culture solution by decreasing Al accumulation in roots.