Expression of the bacterial heavy metal transporter MerC fused with a plant SNARE, SYP121, in Arabidopsis thaliana increases cadmium accumulation and tolerance

Planta. 2012 Apr;235(4):841-50. doi: 10.1007/s00425-011-1543-4. Epub 2011 Nov 17.

Abstract

The bacterial merC gene from the Tn21-encoded mer operon is a potential molecular tool for improving the efficiency of metal phytoremediation. Arabidopsis SNARE molecules, including SYP111, SYP121, and AtVAM3 (SYP22), were attached to the C-terminus of MerC to target the protein to various organelles. The subcellular localization of transiently expressed GFP-fused MerC-SYP111, MerC-SYP121, and MerC-AtVAM3 was examined in Arabidopsis suspension-cultured cells. We found that GFP-MerC-SYP111 and GFP-MerC-SYP121 localized to the plasma membrane, whereas GFP-AtVAM3 localized to the vacuolar membranes. These results demonstrate that SYP111/SYP121 and AtVAM3 target foreign molecules to the plasma membrane and vacuolar membrane, respectively. To enhance the efficiency and potential of plants to sequester and accumulate cadmium from contaminated sites, transgenic Arabidopsis plants expressing MerC, MerC-SYP111, MerC-SYP121, or MerC-AtVAM3 were generated. The transgenic plants that expressed MerC, MerC-SYP121, or MerC-AtVAM3 appeared to be normal, whereas the transgenic that expressed MerC-SYP111 exhibited severe growth defects. The transgenic plants expressing merC-SYP121 were more resistant to cadmium than the wild type and accumulated significantly more cadmium. Thus, the expression of MerC-SYP121 in the plant plasma membrane may provide an ecologically compatible approach for the phytoremediation of cadmium pollution.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / genetics
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / biosynthesis*
  • Arabidopsis Proteins / genetics
  • Biodegradation, Environmental
  • Cadmium / metabolism*
  • Cation Transport Proteins / biosynthesis*
  • Cation Transport Proteins / genetics
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Gene Expression Regulation, Plant
  • Genes, Plant
  • Genetic Engineering
  • Genetic Variation
  • Green Fluorescent Proteins / biosynthesis
  • Green Fluorescent Proteins / genetics
  • Plant Roots / metabolism
  • Plants, Genetically Modified
  • Qa-SNARE Proteins / biosynthesis*
  • Qa-SNARE Proteins / genetics
  • Recombinant Fusion Proteins / biosynthesis*
  • Recombinant Fusion Proteins / genetics
  • SNARE Proteins / biosynthesis*
  • SNARE Proteins / genetics
  • Transformation, Genetic

Substances

  • Arabidopsis Proteins
  • Cation Transport Proteins
  • PEN1 protein, Arabidopsis
  • Qa-SNARE Proteins
  • Recombinant Fusion Proteins
  • SNARE Proteins
  • Cadmium
  • Green Fluorescent Proteins