Abstract
To develop the potential of plant for phytoremediation of methylmercury pollution, a genetically engineered tobacco plant that coexpresses organomercurial lyase (MerB) with the ppk-specified polyphosphate (polyP) and merT-encoding mercury transporter was constructed by integrating a bacterial merB gene into ppk/merT-transgenic tobacco. A large number of independent transgenic tobaccos was obtained, in some of which the merB gene was stably integrated in the plant genome and substantially translated to the expected MerB enzyme in the transgenic tobacco. The ppk/merT/merB-transgenic tobacco callus showed more resistance to methylmercury (CH3Hg+) and accumulated more mercury from CH3Hg+-containing medium than the ppk/merT-transgenic and wild-type progenitors. These results suggest that the MerB enzyme encoded by merB degraded the incorporated CH3Hg+ to Hg2+, which then accumulated as a less toxic Hg-polyP complex in the tobacco cells. Phytoremediation of CH3Hg+ and Hg2+ in the environment with this engineered ppk/merT/merB-transgenic plant, which prevents the release mercury vapor (Hg0) into the atmosphere in addition to generating potentially recyclable mercury-rich plant residues, is believed to be more acceptable to the public than other competing technologies, including phytovolatilization.
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References
Bizily SP, Rugh CL, Meagher RB (2000) Phytodetoxification of hazardous organomercurials by genetically engineered plants. Nat Biotechnol 18:213–217
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 131:463–471
Gatz C, Frohberg C, Wendenburg R (1992) stringent repression and homogenous de-repression by tetracycline of a modified CaMV 35S promoter in intact transgenic tobacco plants. Plant J 40:397–404
Harada M (1995) Minamata disease: methylmercury poisoning in Japan caused by environmental pollution. Crit Rev Toxicol 25:1–24
Kiyono M, Omura T, Fujimori H, Pan-Hou H (1995) Organomercurial resistance determinants in Pseudomonas K-62 are present on two plasmids. Arch Microbiol 163:242–247
Kiyono M, Omura T, Inuzuka M, Fujimori H, Pan-Hou H (1997) Nucleotide sequence and expression of the organomercurial-resistance determinants from a Pseudomonas K-62 plasmid pMR26. Gene 189:151–157
Kramer U (2005) Phytoremediation: novel approaches to clearing up polluted soils. Curr Opin Biotechnol 16:133–141
Lyyra S, Meagher RB, Kim T, Heaton A, Montello P, Balish RS, Merkle SA (2007) Coupling two mercury resistance genes in Easterm cottonwood enhances the processing of organomercury. Plant Biotechnol 5:254–262
Murashige T, Skoog F (1962) A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiol Plant 15:473–449
Nakano T, Murakami S, Shoji T, Yoshida S, Yamada Y, Sato F (1997) A novel protein with DNA binding activity from tobacco chloroplast nucleotide. Plant Cell 27:1673–1682
Nagata T, Kiyono M, Pan-Hou H (2006a) Engineering expression of bacterial polyphosphate kinase in tobacco for mercury remediation. Appl Microbiol Biotechnol 72:777–782
Nagata T, Ishikawa C, Kiyono M, Pan-Hou H (2006b) Accumulation of mercury in transgenic tobacco expressing bacterial polyphosphate. Biol Pharm Bull 29:2350–2353
Nagata T, Nakamura A, Akizawa T, Pan-Hou H (2009) Genetic engineering of transgenic tobacco for enhanced uptake and bioaccumulation of mercury. Biol Pharm Bull 32:1491–1495
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 24:1423–1426
Ruiz ON, Hussein HS, Terry N, Daniell H (2003) Phytoremediation of organomercurial compounds via chloroplast genetic engineering. Plant Physiol 132:1344–1352
Salt DE, Smith RD, Raskin I (1998) Phytoremediation. Annu Rev Plant Physiol Plant Mol Biol 49:643–668
Sambrook J, Fritsch EF, Maniatis T (1989) Molecular cloning: a laboratory manual, 2nd edn. Cold Spring Harbor Laboratory, Cold Spring Harbor
Takeda S, Sato F, Ida K, Yamada Y (1990) Characterization of polypeptides that accumulate in cultured Nicotiana tabacum cells. Plant Cell Physiol 31:215–221
Tsubaki T (1968) Organic mercury poisoning in district along the Agano river. Clin Neurol Tokyo Rinsho Shinkeigaku 8:511–520
Acknowledgments
We are grateful to Dr. M. Kiyono of Kitasato University for her technical assistance in the cloning of pBMK01 and constructive suggestions concerning the manuscript. We also thank A. Kuwahara of this University for her technical assistance. The wild-type tobacco (N. tabacum cv. Samsun NN) was a generous gift from Japan Tobacco Inc. This work was supported in part by a grant-in-aid to H.H. from the Ministry of the Environment, Japan.
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Nagata, T., Morita, H., Akizawa, T. et al. Development of a transgenic tobacco plant for phytoremediation of methylmercury pollution. Appl Microbiol Biotechnol 87, 781–786 (2010). https://doi.org/10.1007/s00253-010-2572-9
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DOI: https://doi.org/10.1007/s00253-010-2572-9