Abstract
It is well known that aluminum ion in soil inhibits plant root growth, however, the actual mechanisms of Al toxicity have not been solved enough. We selected two plant species, rice (toyohatamochi, sabana6, IR36, and IR72) and wheat (ET8, and ES8) to study mechanisms of Al toxicity. First, inhibition of root elongation caused by Al was measured as an indicator for Al toxicity, in hydroponic condition. Unexpectedly, ET8 showed high Al tolerance equal to that of four cultivars of rice and only ES8 was very sensitive to Al toxicity. Second, callose accumulation in plant roots after Al treatment was measured and observed. It was found that there was a distinct correlation between callose amount in elongating zone and inhibition of the root growth in both plant species. Exudation of organic acids and damage of plasma membrane are now under investigation.
