Abstract
Proton is a potential rhizotoxic factors in acid soils, but its toxic mechanism remains unclear. In the present study, we evaluated Al and proton toxicities in both solution and soil culture conditions using proton hypersensitive mutant, namely STOP1. Short-term proton rhizotoxicity, which can be judged by viability of the root apex can be alleviated by exogenous Ca in both wildtype and hypersensitive mutants in similar pattern. In addition, when short-term damage was judged by re-growth test, no difference was observed between wild type and the mutant. These results indicate that hyper-sensitivity of proton of the mutant may be caused by long-term effect of protons. In Al containing acid soil, growth of Al sensitive mutant (AtALMT1-KO) was recovered when the soil was neutralized by calcium carbonate. However, the proton sensitive mutants showed poor recovery. These results suggest that proton toxicity is involved in acid soil.
