Isolation of multidrug resistance associated protein like gene from lead hyperaccumulator common buckwheat and its lead detoxification ability

A multidrug resistance associated protein homolog gene, named FeABCC1, was isolated from a commercial brand of common buckwheat that has high lead tolerance and accumulation ability. The deduced amino acid sequence of FeABCC1 had 64% identity with AtMRP3 (AtABCC3) of Arabidopsis thaliana, and was predicted as integral membrane protein with 12 transmembrane domains. FeABCC1 expression was induced in the shoot of common buckwheat treated with lead. The yeast transformed with FeABCC1 showed a marked increasing in lead tolerance with the gene expression, and accumulated more lead compared to control. Not similar to AtMRP3, FeABCC1 expression did not effect to cadmium tolerance in yeast, and inhibition of glutathione synthesis by buthionine sulfoximine was not effect lead tolerance. These data suggests that FeABCC1 has some role for lead detoxyfication in common buckwheat independently to glutathione chelating.