Plant metallothioneins (MTs), which are cysteine-rich, low-molecular-weight, and metal-binding proteins, play important roles in detoxification, metal ion homeostasis, and metal transport adjustment. In this study, a novel metallothionein gene, designated asScMT2-1-3(GenBank Accession number JQ627644), was identified from sugarcane.ScMT2-1-3was 700 bp long, including a 240 bp open reading frame (ORF) encoding 79 amino acid residues. A His-tagged ScMT2-1-3 protein was successfully expressed inEscherichia colisystem which had increased the host cell’s tolerance to Cd2+, Cu2+, PEG, and NaCl. The expression ofScMT2-1-3was upregulated under Cu2+stress but downregulated under Cd2+stress. Real-time qPCR demonstrated that the expression levels ofScMT2-1-3in bud and root were over 14 times higher than those in stem and leaf, respectively. Thus, both theE. coliassay and sugarcane plantlets assay suggested thatScMT2-1-3is significantly involved in the copper detoxification and storage in the cell, but its functional mechanism in cadmium detoxification and storage in sugarcane cells needs more testification though its expressed protein could obviously increase the hostE. colicell’s tolerance to Cd2+.ScMT2-1-3constitutes thus a new interesting candidate for elucidating the molecular mechanisms of MTs-implied plant heavy metal tolerance/accumulation and for developing sugarcane phytoremediator varieties.
ScMT2-1-3, a Metallothionein Gene of Sugarcane, Plays an Important Role in the Regulation of Heavy Metal Tolerance/Accumulation
