title: ScMT2-1-3, a metallothionein gene of sugarcane, plays an important role in the regulation of heavy metal tolerance/accumulation.
abstract: 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 as ScMT2-1-3 (GenBank Accession number JQ627644), was identified from sugarcane. ScMT2-1-3 was 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 in Escherichia coli system which had increased the host cell's tolerance to Cd(2+), Cu(2+), PEG, and NaCl. The expression of ScMT2-1-3 was upregulated under Cu(2+) stress but downregulated under Cd(2+) stress. Real-time qPCR demonstrated that the expression levels of ScMT2-1-3 in bud and root were over 14 times higher than those in stem and leaf, respectively. Thus, both the E. coli assay and sugarcane plantlets assay suggested that ScMT2-1-3 is 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 host E. coli cell's tolerance to Cd(2+). ScMT2-1-3 constitutes thus a new interesting candidate for elucidating the molecular mechanisms of MTs-implied plant heavy metal tolerance/accumulation and for developing sugarcane phytoremediator varieties.
authors.affiliation: Key Laboratory of Sugarcane Biology and Genetic Breeding, Ministry of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China.
authors.forename: Jinlong
authors.initials: J
authors.lastname: Guo
authors.forename: Liping
authors.initials: L
authors.lastname: Xu
authors.forename: Yachun
authors.initials: Y
authors.lastname: Su
authors.forename: Hengbo
authors.initials: H
authors.lastname: Wang
authors.forename: Shiwu
authors.initials: S
authors.lastname: Gao
authors.forename: Jingsheng
authors.initials: J
authors.lastname: Xu
authors.forename: Youxiong
authors.initials: Y
authors.lastname: Que
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects* / Q000235:genetics; D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000254:growth & development / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant / Q000235:genetics*; D008668:Metallothionein / Q000235:genetics*; D019216:Metals, Heavy / Q000633:toxicity*; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000302:isolation & purification; D031786:Saccharum / Q000187:drug effects / Q000235:genetics* / Q000502:physiology*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics
chemical_list: D019216:Metals, Heavy; D010940:Plant Proteins; D011994:Recombinant Proteins; D008668:Metallothionein