Transgenic Research

, 15:615 | Cite as

Generation of Mercury-Hyperaccumulating Plants through Transgenic Expression of the Bacterial Mercury Membrane Transport Protein MerC

  • Yoshito Sasaki
  • Takahiko Hayakawa
  • Chihiro Inoue
  • Atsushi Miyazaki
  • Simon Silver
  • Tomonobu KusanoEmail author
Original Paper


The merC gene from Acidithiobacillus ferrooxidans functions as a mercury uptake pump. MerC protein localizes in the cytoplasmic membrane of plant cells. When Arabidopsis thaliana and tobacco plants were transformed with the merC gene under the control of the Cauliflower mosaic virus 35S promoter, the resulting overexpression of merC rendered the host plants hypersensitive to Hg2+ and they accumulated approximately twice as much Hg2+ ion as the wild type plants. Thus, bacterial mercuric ion transporters such as MerC may be useful molecular tools for producing transgenic plants that hyperaccumulate Hg2+ ion.


Acidithiobacillus ferrooxidans Arabidopsis MerC Mercury transporter Phytoremediation Tobacco 



We thank Dr. J. Hara (Tohoku University) for help with the ICP-MS measurements. We also thank Drs. S. Matsuyama, H. Yamazaki, and K. Ishii (Tohoku University) for guiding the PIXE analysis. We are grateful to Dr. Thomas Berberich (Iwate Biotechnology Research Center) for critically reading our manuscript. This work was supported in part by a Grant-in-aid (Hazardous Chemicals) from the Ministry of Agriculture, Forestry, and Fisheries of Japan (HC-05-11130-1).


  1. Bae W, Mehra RK, Mulchandani A, Chen W (2001) Genetic engineering of Escherichia coli for enhanced uptake and bioaccumulation of mercury. Appl Environ Microbiol 67:5335–5338PubMedCrossRefGoogle Scholar
  2. Barkay T, Miller SM, Summers AO (2003) Bacterial mercury resistance from atoms to ecosystems. FEMS Microbiol Rev 27:355–384PubMedCrossRefGoogle Scholar
  3. Bizily SP, Kim T, Kandasamy MK, Meagher RB (2003) Subcellular targeting of methylmercury lyase enhances its specific activity for organic mercury detoxification in plants. Plant Physiol 131:463–471PubMedCrossRefGoogle Scholar
  4. Bizily SP, Rugh CL, Summers AO, Meagher RB (1999) Phytoremediation of methylmercury pollution: merB expression in Arabidopsis thaliana confers resistance to organomercurials. Proc Natl Acad Sci USA 96:6808–6813PubMedCrossRefGoogle Scholar
  5. Chen S, Wilson DB (1997) Construction and characterization of Escherichia coli genetically engineered for bioremediation of Hg2+-contaminated environments. Appl Environ Microbiol 63:2442–2445PubMedGoogle Scholar
  6. Clemens S (2001) Molecular mechanisms of plant metal tolerance and homeostasis. Planta 212:475–486PubMedCrossRefGoogle Scholar
  7. Clemens S, Palmgren MG, Kramer U (2002) A long way ahead: understanding and engineering plant metal accumulation. Trends Plant Sci 7:309–315PubMedCrossRefGoogle Scholar
  8. Clough SJ, Bent AF (1998) Floral dip: a simplified method for Agrobacterium-mediated transformation of Arabidopsis thaliana. Plant J 16:735–743PubMedCrossRefGoogle Scholar
  9. Cobbett C, Goldsbrough P (2002) Phytochelatins and metallothioneins: roles in heavy metal detoxification and homeostasis. Annu Rev Plant Biol 53:159–182PubMedCrossRefGoogle Scholar
  10. Eapen S, Dȁ9Souza SF (2005) Prospects of genetic engineering of plants for phytoremediation of toxic metals. Biotechnol Adv 23:97–114PubMedCrossRefGoogle Scholar
  11. Glass DJ (2000) Economic potential of phytoremediation. In: Raskin I, Ensley BD (eds) Phytoremediation of toxic metals: Using plants to clean up the environment. John Wiley & Sons, Inc., New York, pp 15–32Google Scholar
  12. Hayakawa T, Zhu Y, Itoh K, Kimura Y, Izawa T, Shimamoto K, Toriyama S (1992) Genetically engineered rice resistant to rice stripe virus, an insect-transmitted virus. Proc Natl Acad Sci USA 89:9865–9869PubMedCrossRefGoogle Scholar
  13. Hood EE, Gelvin SB, Melchers LS, Hoekema A (1993) New Agrobaterium helper plasmids for gene transfer to plants. Transgen Res 2:208–218CrossRefGoogle Scholar
  14. Hoover DM, Lubkowski J (2002) DNAWorks: an automated method for designing oligonucleotides for PCR-based gene synthesis. Nucleic Acids Res 30:e43PubMedCrossRefGoogle Scholar
  15. Horsch REI, Fry JE, Hoffman NL, Eichholtz D, Rogers SG, Fraley RT (1985) A simple and general method for transferring genes into plants. Science 227:1229–1231CrossRefGoogle Scholar
  16. Inoue C, Kusano T, Silver S (1996) Mercuric ion uptake by Escherichia coli cells producing Thiobacillus ferrooxidans MerC. Biosci Biotech Biochem 60:1289–1292CrossRefGoogle Scholar
  17. Järup L (2003) Hazards of heavy metal contamination. Br Med Bull 68:167–182PubMedCrossRefGoogle Scholar
  18. Koike S, Inoue H, Mizuno D, Takahashi M, Nakanishi H, Mori S, Nishizawa NK (2004) OsYSL2 is a rice metal-nicotianamine transporter that is regulated by iron and expressed in the phloem. Plant J 39:415–424PubMedCrossRefGoogle Scholar
  19. Koizuka N, Imai R, Fujimoto H, Hayakawa T, Kimura Y, Kohno-Murase J, Sakai T, Kawasaki S, Imamura J (2003) Genetic characterization of a pentatricopeptide repeat protein gene, orf687, that restores fertility in the cytoplasmic male-sterile Kosena radish. Plant J 34:407–415PubMedCrossRefGoogle Scholar
  20. Kusano T, Ji G, Inoue C, Silver S (1990) Constitutive synthesis of a transport function encoded by the Thiobacillus ferrooxidans merC gene cloned in Escherichia coli. J Bacteriol 172:2688–2692PubMedGoogle Scholar
  21. Lee J, Reeves RD, Brooks RR, Jaffre T (1977) Isolation and identification of a citrate-complex of nickel from nickel-accumulating plants. Phytochem 16:1503–1505CrossRefGoogle Scholar
  22. Liebert CA, Watson AL, Summers AO (2000) The quality of merC, a module of the mer mosaic. J Mol Evol 51:607–622PubMedGoogle Scholar
  23. Morby AP, Hobman JL, Brown NL (1995) The role of cysteine residues in the transport of mercuric ions by the Tn501 MerT and MerP mercury-resistance proteins. Mol Microbiol 17:25–35PubMedCrossRefGoogle Scholar
  24. Nagy F, Kay SA, Chua NH (1988) Analysis of gene expression in transgenic plants. In: Gelvin SB, Schilperoort RA (eds) Plant molecular biology manual. Kluwer Academic Publishers, Dordrecht, B4: 1–29Google Scholar
  25. Pan-Hou H, Kiyono M, Kawase T, Omura T, Endo G (2001) Evaluation of ppk-specified polyphosphate as a mercury remedial tool. Biol Pharm Bull 24:1423–1426PubMedCrossRefGoogle Scholar
  26. Pilon-Smits E (2005) Phytoremediation. Annu Rev Plant Biol 56:15–39PubMedCrossRefGoogle Scholar
  27. Rawlings DE, Kusano T (1994) Molecular genetics of Thiobacillus ferrooxidans. Microbiol Rev 158:39–55Google Scholar
  28. Rugh CL, Bizily SP, Meagher RB (2000) Phytoreduction of environmental mercury pollution. In: Raskin I, Ensley BD (eds) Phytoremediation of toxic metals: Using plants to clean up the environment. John Wiley & Sons, Inc, New York, pp 151–170Google Scholar
  29. Rugh CL, Wilde HD, Stack NM, Thompson DM, Summers AO, Meagher RB (1996) Mercuric ion reduction and resistance in transgenic Arabidopsis thaliana plants expressing a modified bacterial merA gene. Proc Natl Acad Sci USA 93:3182–3187PubMedCrossRefGoogle Scholar
  30. Sahlman L, Hagglof EM, Powlowski J (1999) Roles of the four cysteine residues in the function of the integral inner membrane Hg2+-binding protein, MerC. Biochem Biophys Res Commun 255:307–311PubMedCrossRefGoogle Scholar
  31. Sahlman L, Wong W, Powlowski J (1997) A mercuric ion uptake role for the integral inner membrane protein, MerC, involved in bacterial mercuric ion resistance. J Biol Chem 272:29518–29526PubMedCrossRefGoogle Scholar
  32. Salt DE, Krämer U (2000) Mechanisms of metal hyperaccumulation in plants In: Raskin I, Ensley BD (eds) Phytoremediation of toxic metals: Using plants to clean up the environment. John Wiley & Sons, Inc., New York, pp 231–246Google Scholar
  33. Sambrook J, Russell DW (2001) Molecular cloning: A laboratory manual, 3rd edn. Cold Spring Harbor Laboratory Press, Cold Spring HarborGoogle Scholar
  34. Sasaki Y, Minakawa T, Miyazaki A, Silver S, Kusano T (2005) Functional dissection of a mercuric ion transporter MerC from Acidithiobacillus ferrooxidans. Biosci Biotechnol Biochem 69:1394–1402PubMedCrossRefGoogle Scholar
  35. Shen WJ, Forde BG (1989) Efficient transformation of Agrobacterium spp. by high voltage electroporation. Nucleic Acids Res 17:83–85Google Scholar
  36. Shiratori T, Inoue C, Sugawara K, Kusano T, Kitagawa Y (1989) Cloning and expression of Thiobacillus ferrooxidans mercury ion resistance genes in Escherichia coli. J Bacterial 171:3458–3464Google Scholar
  37. Silver S., Phung LT (1996) Bacterial heavy metal resistance: new surprises. Annu Rev Microbiol 50:753–789PubMedCrossRefGoogle Scholar
  38. Wilson JR, Leang C, Morby AP, Hobman JL., Brown NL (2000) MerF is a mercury transport protein: different structures but a common mechanism for mercuric ion transporters ? FEBS Lett 472:78–82PubMedCrossRefGoogle Scholar
  39. Yang SH, Berberich T, Sano H, Kusano T (2001) Specific association of transcripts of tbzF and tbz17, tobacco genes encoding basic region leucine zipper-type transcriptional activators, with guard cells of senescing leaves and/or flowers. Plant Physiol 127:23–32PubMedCrossRefGoogle Scholar
  40. Yeargan R, Maiti IB, Nielsen MT, Hunt AG, Wagner GJ (1992) Tissue partitioning of cadmium in transgenic tobacco seedlings and field grown plants expressing the mouse metallothionein I gene. Transgenic Res 1:261–267PubMedCrossRefGoogle Scholar
  41. Zenk MH (1996) Heavy metal detoxification in higher plants. Gene 179:21–30PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2006

Authors and Affiliations

  • Yoshito Sasaki
    • 1
  • Takahiko Hayakawa
    • 2
  • Chihiro Inoue
    • 3
  • Atsushi Miyazaki
    • 1
  • Simon Silver
    • 4
  • Tomonobu Kusano
    • 1
    Email author
  1. 1.Graduate School of Life SciencesTohoku UniversitySendaiJapan
  2. 2.Plantech Research InstituteAoba-kuJapan
  3. 3.Graduate School of Environmental StudiesTohoku UniversitySendaiJapan
  4. 4.Department of Microbiology and ImmunologyUniversity of IllinoisChicagoUSA

Personalised recommendations