title: Novel cysteine-rich peptides from Digitaria ciliaris and Oryza sativa enhance tolerance to cadmium by limiting its cellular accumulation.
abstract: 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. Five DcCDT1 homologs (here termed OsCDT1-OsCDT5) have been identified in rice, and all of them were up-regulated to varying degrees in the above-ground tissues by CdCl(2) treatment. Localization of green fluorescent protein fusions suggests that DcCDT1 and OsCDT1 are targeted to both cytoplasmic membranes and cell walls of plant cells. Transgenic Arabidopsis thaliana plants overexpressing DcCDT1 or OsCDT1 displayed a Cd-tolerant phenotype and, consistent with our yeast data, accumulated lower amounts of Cd when grown on CdCl(2). Collectively, our data suggest that DcCDT1 and OsCDT1 function to prevent entry of Cd into yeast and plant cells and thereby enhance their Cd tolerance.
authors.affiliation: Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Kuramata
authors.forename: Shuichi
authors.initials: S
authors.lastname: Masuya
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Etsuko
authors.initials: E
authors.lastname: Kitagawa
authors.forename: Chihiro
authors.initials: C
authors.lastname: Inoue
authors.forename: Satoru
authors.initials: S
authors.lastname: Ishikawa
authors.forename: Shohab
authors.initials: S
authors.lastname: Youssefian
authors.forename: Tomonobu
authors.initials: T
authors.lastname: Kusano
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D019256:Cadmium Chloride / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D031746:Digitaria / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D012275:Oryza / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D010940:Plant Proteins; D018749:RNA, Plant; D019256:Cadmium Chloride