Abstract
We reported previously that aluminum (Al) triggers the production of reactive oxygen species at the accumulation site of Al on pea roots. By use of superoxide anion (O2-)-specific indicators, CLA and MCLA, we confirmed that Al induces O2- both inside and outside cells. Next we examined the relationship between O2- production and root elongation inhibition caused by Al, by use of Tiron as a O2--specific scavenger. The chelate effect of Tiron on 10 μM Al was not observed entirely with up to 25 μM Tiron by the PCV method. Tiron (10 μM) inhibited completely the Al-triggered O2- production, root elongation inhibition and callose production during the treatment with various concentrations of Al (0-6 μM). These results suggest that Al induces O2- both extracellularly and intracellularly. Furthermore, it is possible that the Al-triggered O2- production is a cause of root elongation inhibition.
