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Improving Flavour and Quality of Tomatoes by Expression of Synthetic Gene Encoding Sweet Protein Monellin

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Abstract

Monellin a sweet-tasting protein exists naturally as a heterodimer of two non-covalently linked subunits chain A and B, which loses its sweetness on denaturation. In this study, we validated the expression of a synthetic monellin gene encoding a single polypeptide chain covalently linking the two subunits under T7 and fruit-ripening-specific promoters in Escherichia coli and tomato fruits, respectively. Purified recombinant monellin protein retained its sweet flavour at 70 °C and pH 2. We developed 15 transgenic T0 tomato plants overexpressing monellin, which were devoid of any growth penalty or phenotypic abnormalities during greenhouse conditions. T-DNA integration and fruit-specific heterologous expression of monellin had occurred in these transgenic tomato lines. ELISA revealed that expression of monellin was 4.5 % of the total soluble fruit protein. Functional analyses of transgenic tomatoes of T2-5 and T2-14 lines revealed distinctly strong sweetness compared with wild type. Monellin a potential non-carbohydrate sweetener, if expressed in high amounts in fruits and vegetables, would enhance their flavour and quality.

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References

  1. Yarmolinsky, D. A., Zuker, C. S., & Ryba, N. J. (2009). Common sense about taste: From mammals to insects. Cell, 139, 234–244.

    Article  CAS  Google Scholar 

  2. Dansby, R. (1997). Sweet science: overexpression of monellin in yeast. Nature Biotechnology, 15, 419–420.

    Article  CAS  Google Scholar 

  3. Chen, Z., Cai, H., Lu, F., & Du, L. (2005). High-level expression of a synthetic gene encoding a sweet protein, monellin, in Escherichia coli. Biotechnology Letters, 27, 1745–1749.

    Article  CAS  Google Scholar 

  4. Nilesh, A., Jayant, B., & Udgaonkar, (2011). Heterologous expression, purification and characterization of heterodimeric monellin. Protein Expression and Purification, 2, 248–253.

    Google Scholar 

  5. Lee, Seung-Bum, Kim, Yangseon, Lee, Jeonghwa, Kwang-Ji, O. H., Byun, Myoung-Ok, Jeong, Mi-Jeong, & Bae, Shin-Chul. (2012). Stable expression of the sweet protein monellin variant MNEI in tobacco chloroplasts. Plant Biotechnology Reports, 6, 285–295.

    Article  Google Scholar 

  6. Kohmura, Masanori, Nio, Noriki, & Ariyoshi, Yasuo. (1992). Highly probable active site of the sweet protein monellin. Bioscience, Biotechnology, and Biochemistry, 56, 1937–1942.

    Article  CAS  Google Scholar 

  7. Tancredi, T., Iijima, H., Saviano, G., et al. (1992). Structural determination of the active site of a sweet protein. A 1H NMR investigation of pMNEI. FEBS Letters, 310, 27–30.

    Article  CAS  Google Scholar 

  8. Kim, S. H., Kang, C. H., Kim, R., Cho, J. M., Lee, Y. B., & Lee, T. K. (1989). Redesigning a sweet protein: Increased stability and renaturability. Protein Engineering, 2, 571–575.

    Article  CAS  Google Scholar 

  9. Pen˜arrubia, L., Kim, R., Giovannoni, J., Kim, S. H., & Fischer, R. L. (1992). Production of the sweet protein monellin in transgenic plants. Nature Biotechnology, 10, 561–564.

    Article  Google Scholar 

  10. Spadaccini, R., Trabucco, F., Saviano, G., Picone, D., Crescenzi, O., Tancredi, T., & Temussi, P. A. (2003). The mechanism of interaction of sweet proteins with the T1R2–T1R3 receptor: Evidence from the solution structure of G16A-MNEI. Journal of Molecular Biology, 328, 683–692.

    Article  CAS  Google Scholar 

  11. Kaul, Tanushri, Reddy, Palakolanu Sudhakar, Srikrishna Mahanty, V., Reddy, Ramesha A., Bhumesh Kumar, Sopory, Sudhir K., & Reddy, Malireddy K. (2011). Biochemical and molecular characterization of stress-induced β-carbonic anhydrase from a C4 plant Pennisetum glaucum. Journal of Plant Physiology, 6, 601–610.

    Article  Google Scholar 

  12. Krishnan, H. B., & Natarajan, S. S. (2009). A rapid method for depletion of Rubisco from soybean (Glycine max) leaf for proteomic analysis of lower abundance proteins. Phytochemistry, 70, 1958–1964.

    Article  CAS  Google Scholar 

  13. Inglett, G. E., & May, J. F. (1969). Serendipity berries—source of a new intense sweetener. Journal of Food Science, 34, 408–411.

    Article  CAS  Google Scholar 

  14. Morris, J. A., Martenson, R., Deibler, G., & Cagan, R. H. (1973). Characterization of monellin, a protein that tastes sweet. Journal of Biological Chemistry, 248, 534–539.

    CAS  Google Scholar 

  15. Ogata, C., Hatada, M., Tomlinson, G., Shin, W. C., & Kim, S. H. (1987). Crystal structure of the intensely sweet protein monellin. Nature, 328, 739–742.

    Article  CAS  Google Scholar 

  16. Chen, Zhongjun, Cai, Heng, Fuping, Lu, & Lianxiang, Du. (2005). High-level expression of a synthetic gene encoding a sweet protein, monellin, in Escherichia coli. Biotechnology Letters, 27, 1745–1749.

    Article  CAS  Google Scholar 

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Acknowledgments

The authors are grateful to the Rapid Grant for Young Investigator (RGYI) and Biocare Grants from the Department of Biotechnology, Government of India awarded to Dr. Tanushri Kaul for funding the research.

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Authors and Affiliations

  1. Plant Molecular Biology Laboratory, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India

    Chinreddy Subramanyam Reddy, Tanushri Kaul, Tahmina Islam & Malireddy K. Reddy

  2. Department of Botany and Microbiology, Acharya Nagarjuna University, Guntur, 522510, Andhra Pradesh, India

    Chinreddy Subramanyam Reddy & Muvva Vijayalakshmi

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  1. Chinreddy Subramanyam Reddy
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  2. Muvva Vijayalakshmi
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  3. Tanushri Kaul
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  4. Tahmina Islam
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  5. Malireddy K. Reddy
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Corresponding author

Correspondence to Tanushri Kaul.

Electronic supplementary material

Supplementary Fig. 1. Regenerating transgenic tomato lines harbouring monellin gene through agro-mediated plant transformation. Different stages of tomato transformation: Tomato seed germination (A); Pre-cultured and Co-cultivated explants (B), Co-cultivated explants on regeneration medium showing induction of shoots (C-E), Shoots showing elongation (F), Root induction (G), hardening of plants (H) and control and transgenic plants transferred to pots in greenhouse (I).

Supplementary material 1 (TIFF 1055 kb)

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Reddy, C.S., Vijayalakshmi, M., Kaul, T. et al. Improving Flavour and Quality of Tomatoes by Expression of Synthetic Gene Encoding Sweet Protein Monellin. Mol Biotechnol 57, 448–453 (2015). https://doi.org/10.1007/s12033-015-9838-5

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  • DOI: https://doi.org/10.1007/s12033-015-9838-5

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