A novel plant cysteine-rich peptide family conferring cadmium tolerance to yeast and plants.

We have identified a novel cDNA clone, termed DcCDT1, from Digitaria ciliaris, that confers cadmium (Cd)-tolerance to yeast (Saccharomyces cerevisiae). The gene encodes a predicted peptide of 55 amino acid residues of which 15 (27.3%) are cysteine residues.

Novel cysteine-rich peptides from Digitaria ciliaris and Oryza sativa enhance tolerance to cadmium by limiting its cellular accumulation.

By means of functional screening using the cadmium (Cd)-sensitive ycf1 yeast mutant, we have isolated a novel cDNA clone, DcCDT1, from Digitaria ciliaris growing in a former mining area in northern Japan, and have shown that it confers Cd tolerance to the yeast cells, which accumulated almost 2-fold lower Cd levels than control cells. The 521 bp DcCDT1 cDNA contains an open reading frame of 168 bp and encodes a deduced peptide, DcCDT1, that is 55 amino acid residues in length, of which 15 (27.3%) are cysteine residues.