pp 1–8 | Cite as

SCARECROW promoter-driven expression of a bacterial mercury transporter MerC in root endodermal cells enhances mercury accumulation in Arabidopsis shoots

  • Shimpei Uraguchi
  • Yuka Sone
  • Aino Yoshikawa
  • Michi Tanabe
  • Haruka Sato
  • Yuto Otsuka
  • Ryosuke Nakamura
  • Yasukazu Takanezawa
  • Masako KiyonoEmail author
Short Communication


Main conclusion

Mercury accumulation in Arabidopsis shoots is accelerated by endodermis specific expression of fusion proteins of a bacterial mercury transporter MerC and a plant SNARE SYP121 under control of SCARECROW promoter.


We previously demonstrated that the CaMV 35S RNA promoter (p35S)-driven ubiquitous expression of a bacterial mercury transporter MerC, fused with SYP121, an Arabidopsis SNARE protein increases mercury accumulation of Arabidopsis. To establish an improved fine-tuned mercury transport system in plants for phytoremediation, the present study generated and characterized transgenic Arabidopsis plants expressing MerC-SYP121 specifically in the root endodermis, which is a crucial cell type for root element uptake. We generated four independent transgenic Arabidopsis lines expressing a transgene encoding mCherry-MerC-SYP121 under the control of the endodermis-specific SCARECROW promoter (hereafter pSCR lines). Quantitative real-time PCR analysis showed that expression levels of the transgene in roots of the pSCR lines were 3–23% of the p35S driven-overexpressing line. Confocal microscopy analysis showed that mCherry-MerC-SYP121 was dominantly expressed in the endodermis of the meristematic zone as well as in the mature zone of the pSCR roots. Mercury accumulation in shoots of the pSCR lines exposed to inorganic mercury was overall higher than the wild-type and comparable to the p35S over-expressing line. These results suggest that endodermis-specific expression of the MerC-SYP121 fusion proteins in plant roots sufficiently enhances mercury uptake and accumulation into shoots, which would be an ideal phenotype for phytoremediation of mercury-contaminated environments.


Bacterial mercury transporter Cell-type specificity Endodermis MerC Phytoremediation SCARECROW 



SCARECROW promoter


Soluble N-ethylmaleimide-sensitive factor protein attachment protein receptor



We thank Prof. Dr. Angelika Mustroph (University of Bayreuth) for providing a plasmid containing the pSCR fragment. This work was partly supported by the Japan Society for the Promotion of Science (Grant nos. 15H02839 and 18H03401 to M.K.).

Supplementary material

425_2019_3186_MOESM1_ESM.pdf (746 kb)
Supplementary material 1 (PDF 746 kb)
425_2019_3186_MOESM2_ESM.xlsx (10 kb)
Supplementary material 2 (XLSX 9 kb)


  1. Alassimone J, Naseer S, Geldner N (2010) A developmental framework for endodermal differentiation and polarity. Proc Natl Acad Sci USA 107:5214–5219CrossRefGoogle Scholar
  2. Awasthi A, Zeng X, Li J (2016) Environmental pollution of electronic waste recycling in India: a critical review. Environ Pollut 211:259–270CrossRefGoogle Scholar
  3. Barberon M, Geldner N (2014) Radial transport of nutrients: the plant root as a polarized epithelium. Plant Physiol 166:528–537CrossRefGoogle Scholar
  4. Besserer A, Burnotte E, Bienert G, Chevalier AS, Errachid A, Grefen C, Blatt MR, Chaumont F (2012) Selective regulation of maize plasma membrane aquaporin trafficking and activity by the SNARE SYP121. Plant Cell 24:3463–3481CrossRefGoogle Scholar
  5. Bizily S, Rugh C, Summers A, Meagher R (1999) Phytoremediation of methylmercury pollution: merB expression in Arabidopsis thaliana confers resistance to organomercurials. Proc Natl Acad Sci USA 96:6808–6813CrossRefGoogle Scholar
  6. Bizily S, Rugh C, Meagher R (2000) Phytodetoxification of hazardous organomercurials by genetically engineered plants. Nat Biotechnol 18:213–217CrossRefGoogle Scholar
  7. Bizily S, Kim T, Kandasamy MK, Meagher R (2003) Subcellular targeting of methylmercury lyase enhances its specific activity for organic mercury detoxification in plants. Plant Physiol 131:463–471CrossRefGoogle Scholar
  8. Castilhos Z, Rodrigues-Filho S, Cesar R, Rodrigues A, Villas-Bôas R, de Jesus I, Lima M, Faial K, Miranda A, Brabo E, Beinhoff C, Santos E (2015) Human exposure and risk assessment associated with mercury contamination in artisanal gold mining areas in the Brazilian Amazon. Environ Sci Pollut Res 22:11255–11264CrossRefGoogle Scholar
  9. Clough S, Bent A (1998) Floral dip: a simplified method for Agrobacterium-mediated transformation of Arabidopsis thaliana. Plant J 16:735–743CrossRefGoogle Scholar
  10. Geelen D, Leyman B, Batoko H, Di Sansebastiano GPP, Moore I, Blatt MR (2002) The abscisic acid-related SNARE homolog NtSyr1 contributes to secretion and growth: evidence from competition with its cytosolic domain. Plant Cell 14:387–406CrossRefGoogle Scholar
  11. Hachez C, Laloux T, Reinhardt H, Cavez D, Degand H, Grefen C, Rycke R, Inzé D, Blatt MR, Russinova E, Chaumont F (2014) Arabidopsis SNAREs SYP61 and SYP121 coordinate the trafficking of plasma membrane aquaporin PIP2;7 to modulate the cell membrane water permeability. Plant Cell 26:3132–3147CrossRefGoogle Scholar
  12. Jing Y, He Z, Yang X, Sun C (2008) Evaluation of soil tests for plant available mercury in a soil–crop rotation system. Commun Soil Sci Plant Anal 39:3032–3046CrossRefGoogle Scholar
  13. Kasajima I, Ide Y, Ohkama-Ohtsu N, Hayashi H, Yoneyama T, Fujiwara T (2004) A protocol for rapid DNA extraction from Arabidopsis thaliana for PCR analysis. Plant Mol Biol Report 22:49–52CrossRefGoogle Scholar
  14. Kiyono M, Oka Y, Sone Y, Tanaka M, Nakamura R, Sato MH, Pan-Hou H, Sakabe K, Inoue K (2012) Expression of the bacterial heavy metal transporter MerC fused with a plant SNARE, SYP121, in Arabidopsis thaliana increases cadmium accumulation and tolerance. Planta 235:841–850CrossRefGoogle Scholar
  15. Kiyono M, Oka Y, Sone Y, Nakamura R, Sato MH, Sakabe K, Pan-Hou H (2013) Bacterial heavy metal transporter MerC increases mercury accumulation in Arabidopsis thaliana. Biochem Eng J 71:19–24CrossRefGoogle Scholar
  16. Kühnlenz T, Schmidt H, Uraguchi S, Clemens S (2014) Arabidopsis thaliana phytochelatin synthase 2 is constitutively active in vivo and can rescue the growth defect of the PCS1-deficient cad1-3 mutant on Cd-contaminated soil. J Exp Bot 65:4241–4253CrossRefGoogle Scholar
  17. Laurenzio DL, Wysocka-Diller J, Malamy J, Pysh L, Helariutta Y, Freshour G, Hahn M, Feldmann K, Benfey P (1996) The SCARECROW gene regulates an asymmetric cell division that is essential for generating the radial organization of the Arabidopsis root. Cell 86:423–433CrossRefGoogle Scholar
  18. Li W, Tse H (2015) Health risk and significance of mercury in the environment. Environ Sci Pollut Res 22:192–201CrossRefGoogle Scholar
  19. Li B, Kamiya T, Kalmbach L, Yamagami M, Yamaguchi K, Shigenobu S, Sawa S, Danku J, Salt DE, Geldner N, Fujiwara T (2017) Role of LOTR1 in nutrient transport through organization of spatial distribution of root endodermal barriers. Curr Biol 27:758–765CrossRefGoogle Scholar
  20. Liang J, Feng C, Zeng G, Zhong M, Gao X, Xiaodong Li, He X, Xin Li, Fang Y, Mo D (2017) Atmospheric deposition of mercury and cadmium impacts on topsoil in a typical coal mine city, Lianyuan, China. Chemosphere 189:198–205CrossRefGoogle Scholar
  21. Liebert CA, Hall RM, Summers AO (1999) Transposon Tn21, flagship of the floating genome. Microbiol Mol Biol Rev 63:507–522Google Scholar
  22. Malamy J, Benfey P (1997) Analysis of SCARECROW expression using a rapid system for assessing transgene expression in Arabidopsis roots. Plant J 12:957–963CrossRefGoogle Scholar
  23. Marquès-Bueno MD, Morao AK, Cayrel A, Platre MP, Barberon M, Caillieux E, Colot V, Jaillais Y, Roudier F, Vert G (2016) A versatile multisite gateway-compatible promoter and transgenic line collection for cell type-specific functional genomics in Arabidopsis. Plant J 85:320–333CrossRefGoogle Scholar
  24. McGrath SP, Zhao FJ (2003) Phytoextraction of metals and metalloids from contaminated soils. Curr Opin Biotechnol 14:277–282CrossRefGoogle Scholar
  25. Mustroph A, Zanetti M, Jang CJ, Holtan HE, Repetti PP, Galbraith DW, Girke T, Bailey-Serres J (2009) Profiling translatomes of discrete cell populations resolves altered cellular priorities during hypoxia in Arabidopsis. Proc Natl Acad Sci USA 106:18843–18848CrossRefGoogle Scholar
  26. Nakagawa R, Yumita Y (1998) Change and behavior of residual mercury in paddy soils and rice of Japan. Chemosphere 37:1483–1487CrossRefGoogle Scholar
  27. Nakagawa T, Suzuki T, Murata S, Nakamura S, Hino T, Maeo K, Tabata R, Kawai T, Tanaka K, Niwa Y, Watanabe Y, Nakamura K, Kimura T, Ishiguro S (2007) Improved gateway binary vectors: high-performance vectors for creation of fusion constructs in transgenic analysis of plants. Biosci Biotechnol Biochem 71:2095–2100CrossRefGoogle Scholar
  28. Nakayama T, Shinohara H, Tanaka M, Baba K, Ogawa-Ohnishi M, Matsubayashi Y, Nakayama T, Shinohara H, Tanaka M, Baba K, Ogawa-Ohnishi M, Matsubayashi Y (2017) A peptide hormone required for Casparian strip diffusion barrier formation in Arabidopsis roots. Science 355:284–286CrossRefGoogle Scholar
  29. Sasaki A, Yamaji N, Yokosho K, Ma JF (2012) Nramp5 is a major transporter responsible for manganese and cadmium uptake in rice. Plant Cell 24:2155–2167CrossRefGoogle Scholar
  30. Sato MH, Nakamura N, Ohsumi Y, Kouchi H, Kondo M, Hara-Nishimura I, Nishimura M, Wada Y (1997) The AtVAM3 encodes a syntaxin-related molecule implicated in the vacuolar assembly in Arabidopsis thaliana. J Biol Chem 272:24530–24535CrossRefGoogle Scholar
  31. Sone Y, Uraguchi S, Takanezawa Y, Nakamura R, Pan-Hou H, Kiyono M (2017) A novel role of MerC in methylmercury transport and phytoremediation of methylmercury contamination. Biol Pharm Bull 40:1125–1128CrossRefGoogle Scholar
  32. Sutter JUU, Campanoni P, Tyrrell M, Blatt MR (2006) Selective mobility and sensitivity to SNAREs is exhibited by the Arabidopsis KAT1K+ channel at the plasma membrane. Plant Cell 18:935–954CrossRefGoogle Scholar
  33. Takano J, Tanaka M, Toyoda A, Miwa K, Kasai K, Fuji K, Onouchi H, Naito S, Fujiwara T (2010) Polar localization and degradation of Arabidopsis boron transporters through distinct trafficking pathways. Proc Natl Acad Sci USA 107:5220–5225CrossRefGoogle Scholar
  34. Tennstedt P, Peisker D, Böttcher C, Trampczynska A, Clemens S (2009) Phytochelatin synthesis is essential for the detoxification of excess zinc and contributes significantly to the accumulation of zinc. Plant Physiol 149:938–948CrossRefGoogle Scholar
  35. Ueno D, Sasaki A, Yamaji N, Miyaji T, Fujii Y, Takemoto Y, Moriyama S, Che J, Moriyama Y, Iwasaki K, Ma JF (2015) A polarly localized transporter for efficient manganese uptake in rice. Nat Plants 1:15170CrossRefGoogle Scholar
  36. Uraguchi S, Tanaka N, Hofmann C, Abiko K, Ohkama-Ohtsu N, Weber M, Kamiya T, Sone Y, Nakamura R, Takanezawa Y, Kiyono M, Fujiwara T, Clemens S (2017) Phytochelatin synthase has contrasting effects on cadmium and arsenic accumulation in rice grains. Plant Cell Physiol 58:1730–1742CrossRefGoogle Scholar
  37. Uraguchi S, Sone Y, Kamezawa M, Tanabe M, Hirakawa M, Nakamura R, Takanezawa Y, Kiyono M (2019) Ectopic expression of a bacterial mercury transporter MerC in root epidermis for efficient mercury accumulation in shoots of Arabidopsis plants. Sci Rep 9:4347CrossRefGoogle Scholar
  38. Wysocka-Diller J, Helariutta Y, Fukaki H, Malamy J, Benfey P (2000) Molecular analysis of SCARECROW function reveals a radial patterning mechanism common to root and shoot. Development 127:595–603Google Scholar
  39. Zeng X, Xu X, Boezen HM, Huo X (2016) Children with health impairments by heavy metals in an e-waste recycling area. Chemosphere 148:408–415CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  • Shimpei Uraguchi
    • 1
  • Yuka Sone
    • 1
  • Aino Yoshikawa
    • 1
  • Michi Tanabe
    • 1
  • Haruka Sato
    • 1
  • Yuto Otsuka
    • 1
  • Ryosuke Nakamura
    • 1
  • Yasukazu Takanezawa
    • 1
  • Masako Kiyono
    • 1
    Email author
  1. 1.Department of Public Health, School of PharmacyKitasato UniversityTokyoJapan

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