Host: The Japanese Society of Plant Physiologists
Pages 0024
Malate excretion is major aluminum (Al) tolerant mechanism in Arabidopsis and which is mainly regulated by AtALMT1 gene expression and AtALMT1 protein activation. Malate release and gene expression are sharply induced by Al within a couple of hours. Once induced gene expression, AtALMT1 protein would be activated by Al. All these responses are nearly specific to Al because other ion treatments (e.g. proton, heavy metals and Al-mimic trivalent cations) do not induce malate release and activate the protein. A set of pharmaceutical characterization indicates that both gene expression and protein activation involve a typical reversible protein phosphorylation. Promoter GUS reporter assay showed that Al inducible gene expression is adapted to protect the root apex. In addition, one natural Al-hyper sensitive accession, Wa-0, involves nonsense mutation in AtALMT1. These results indicate that AtALMT1 system is specialized for Al tolerant mechanism, which is adapted to minimize negative impact, namely carbon loss.
