Abstract
In this study, the cDNA of homocysteine S-methyltransferase was isolated from Aegilops tauschii Coss., with the gene accordingly designated as AetHMT1. Similar to other methyltransferases, AetHMT1 contains a GGCCR consensus sequence for a possible zinc-binding motif near the C-terminal and a conserved cysteine residue upstream of the zinc-binding motif. Analysis of AetHMT1 uncovered no obvious chloroplast or mitochondrial targeting sequences. We functionally expressed AetHMT1 in Escherichia coli and confirmed its biological activity, as evidenced by a positive HMT enzyme activity of 164.516 ± 17.378 nmol min-1 mg-1 protein when catalyzing the transformation of L-homocysteine. Compared with the bacterium containing the empty vector, E. coli harboring the recombinant AetHMT1 plasmid showed much higher tolerance to selenate and selenite. AetHMT1 transcript amounts in different organs were increased by Na2SeO4 treatment, with roots accumulating higher amounts than stems, old leaves and new leaves. We have therefore successfully isolated HMT1 from Ae. tauschii and characterized the biochemical and physiological functions of the corresponding protein.
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Abbreviations
- HMT:
-
homocysteine S-methyltransferase
- Bp:
-
base pair
- RT-PCR:
-
reverse transcription polymerase chain reaction
- SMT:
-
selenocysteine methyltransferase
References
Ari, Ş., Çakır, Ö., Turgut-Kara, N. 2010. Selenium tolerance in Astragalus chrysochlorus: identification of a cDNA fragment encoding a putative Selenocysteine methyltransferase. Acta Physiol. Plant. 32:1085–1092.
Ausubel, F.M., Glazebrook, J., Greenberg, J., Katagiri, F., Mindrinos, M., Yu, G.L. 1993. Analysis of the Arabidopsis Defense Response to Pseudomonas Pathogens. J. Cell Biol. 14:393–403.
Bourgis, F., Roje. S., Nuccio, M.L., Fisher, D.B., Tarczynski, M.C., Li, C.J., Herschbach, C., Rennenberg, H., Pimenta, M.J., Shen, T.L., Gage, D.A., Hanson, A.D. 1999. S-methylmethionin plays a major role in phloem sulfur transport and is synthesized by a novel type of methyltransferase. Plant Cell 11:1485–1497.
Bradford, M.M. 1976. Rapid and Sensitive Method for Quantitation of Microgram Quantities of Protein Utilizing Principle of Protein-Dye Binding. Anal. Biochem. 72:248–254.
Brown, T. A., Shrift, A. 1982. Selenium: Toxicity and Tolerance in Higher Plants. Biol. Rev. 57:59–84.
Chen, X., Yang, G., Chen, J., Chen, X., Wen, Z., Ge, K. 1980. Studies on the relations of selenium and Keshan disease. Biol. Trace Elem. Res. 2:91–107.
Ebert, R., Jakob, F. 2007. Selenium deficiency as a putative risk factor for osteoporosis. International Congress Series 1297:158–164.
Guo, Z.F., Zhang, Z.B., Xu P., Guo, Y.N. 2013. Analysis of Nutrient Composition of Purple Wheat, Cereal Res. Commun. 41:293–303.
Hartikainen, H. 2005. Biogeochemistry of selenium and its impact on food chain quality and human health. J. Trace Elem. Med. Bio. 18:309–318.
Hu, B. L., Huang, D.R., Xiao Y.Q., Fan Y.Y., Chen D.Z., Zhuang J.Y. 2016. Mapping QTLs for Mineral Element Contents in Brown and Milled Rice Using an Oryza sativa ×O. rufpogon Backcross Inbred Line Population. Cereal Res. Commun. 44:57–68.
Jia, J., Zhao, S., Kong, X., Li, Y., Zhao, G., He, W., Appels, R., Pfeifer, M., Tao, Y., Zhang, X., Jing, R., Zhang, C., Ma, Y., Gao, L., Gao, C., Spannagl, M., Mayer, K.F., Li, D., Pan, S., Zheng, F., Hu, Q., Xia, X., Li, J., Liang, Q., Chen, J., Wicker, T., Gou, C., Kuang, H., He, G., Luo, Y., Keller, B., Xia, Q., Lu, P., Wang, J., Zou, H., Zhang, R., Xu, J., Gao, J., Middleton, C., Quan, Z., Liu, G., Wang, J., Yang, H., Liu, X., He, Z., Mao, L., Wang, J. 2013. Aegilops tauschii draft genome sequence reveals a gene repertoire for wheat adaptation. Nature 496:91–95.
Koutmos, M., Pejchal, R., Bomer, T.M., Matthews, R.G., Smith, J.L., Ludwig, M.L. 2008. Metal active site elasticity linked to activation of homocysteine in methionine synthases. Proc. Natl. Acad. Sci. U.S.A. 105:3286–3291.
Laemmli, U.K. 1970. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature 227:680–685.
Ling, H.Q., Zhao, S., Liu, D., Wang, J., Sun, H., Zhang, C., Fan, H., Li, D., Dong, L., Tao, Y., Gao, C., Wu, H., Li, Y., Cui, Y., Guo, X., Zheng, S., Wang, B., Yu, K., Liang, Q., Yang, W., Lou, X., Chen, J., Feng, M., Jian, J., Zhang, X., Luo, G., Jiang, Y., Liu, J., Wang, Z., Sha, Y., Zhang, B., Wu, H., Tang, D., Shen, Q., Xue, P., Zou, S., Wang, X., Liu, X., Wang, F., Yang, Y., An, X., Dong, Z., Zhang, K., Zhang, X., Luo, M.C., Dvorak, J., Tong, Y., Wang, J., Yang, H., Li, Z., Wang, D., Zhang, A., Wang, J. 2013. Draft genome of the wheat A-genome progenitor Triticum urartu. Nature 496:87–90.
Lozada-Ramirez, J.D., Martinez-Martinez, I., Garcia-Carmona, F., Sanchez-Ferrer, A. 2008. Cloning, overexpression, purification, and characterization of S-adenosylhomocysteine hydrolase from Corynebacterium efficiens YS-314. Biotechnol. Progr. 24:120–127.
Lyi, S.M., Heller, L.I., Rutzke, M., Welch, R.M., Kochian, L.V., Li, L. 2005. Molecular and biochemical characterization of the selenocysteine Se-methyltransferase gene and Se-methylselenocysteine synthesis in broccoli. Plant Physiol. 138:409–420.
Lyi, S.M., Zhou, X., Kochian, L.V., Li, L. 2007. Biochemical and molecular characterization of the homocysteine S-methyltransferase from broccoli (Brassica oleracea var. italica). Phytochem. 68:1112–1119.
Lyons, G.H., Judson, G.J., Ortiz-Monasterio, I., Genc, Y., Stangoulis, J.C., Graham, R.D. 2005. Selenium in Australia: selenium status and biofortification of wheat for better health. J. Trace Elem. Med. Bio. 19:75–82.
Millian, N.S., Garrow, T.A. 1998. Human betaine-homocysteine methyltransferase is a zinc metalloenzyme. Arch. Biochem. Biophys. 356:93–98.
Neuhierl, B., Böck, A. 1996. On the mechanism of selenium tolerance in selenium-accumulating plants. Purification and characterization of a specific selenocysteine methyltransferase from cultured cells of Astragalus bisculatus. Eur. J. Biochem. 239:235–238.
Neuhierl, B., Thanbichler, M., Lottspeich, F., Böck, A. 1999. A family of S-methylmethionine-dependent thiol/ selenol methyltransferases – Role in selenium tolerance and evolutionary relation. J. Biolog. Chem. 274:5407–5414.
Peariso, K., Goulding, C.W., Huang, S., Matthews, R.G., Penner-Hahn, J.E. 1998. Characterization of the zinc binding site in methionine synthase enzymes of Escherichia coli: The role of zinc in the methylation of homocysteine. J. Am. Chem. Soc. 120:8410–8416.
Liu, P., Zhou, J.P., Xu, X.L., Hao, Q.Q., Wen, X.Y., Wang, L.,Tian, Y.P. 2014. Activity assay and preservation of S-homocysteine methyltransferas. International Journal of Laboratory Medicine 35:1526–1528.
Peng, A., and Yang, C.L. 1991. Examination of the roles of selenium in the Kaschin-Beck disease. Biol. Trace Elem. Res. 28:1–9.
Ranocha, P., Bourgis, F., Ziemak, M.J., Rhodes, D., Gage, D.A., Hanson, A.D. 2000. Characterization and functional expression of cDNAs encoding methionine-sensitive and insensitive homocysteine S-methyltransferases from Arabidopsis. J. Biolog. Chem. 275:15962–15968.
Ranocha, P., McNeil, S.D., Ziemak, M.J., Li, C., Tarczynski, M.C., Hanson, A.D. 2001. The S-methylmethionine cycle in angiosperms: ubiquity, antiquity and activity. Plant J. 25:575–584.
Sambrook, J., Fritsch, E.F., Maniatis, T. 1989. Molecular cloning: A laboratory manual: 2nd ed. Immunology 49:895–909.
Schiavon, M., Pilon-Smits, E.A. 2017. Selenium Biofortification and Phytoremediation Phytotechnologies: A Review. J. Environ. Qual. 46:10–19.
Sors, T.G., Ellis, D.R., Salt, D.E. 2005. Selenium uptake, translocation, assimilation and metabolic fate in plants. Photosynth. Res. 86:373–389.
Sors, T.G., Martin, C.P., Salt, D.E. 2009. Characterization of selenocysteine methyltransferases from Astragalus species with contrasting selenium accumulation capacity. Plant J. 59:110–122.
Szira, F., Monostori, I., Galiba,G., Rakszegi, M., Bálint, A.F. 2014. Micronutrient Contents and Nutritional Values of Commercial Wheat Flours and Flours of Field-grown Wheat Varieties – A Survey in Hungary. Cereal Res. Commun. 42:293–302.
Thomson, C.D. 2004. Assessment of requirements for selenium and adequacy of selenium status: a review. Eur. J. Clin. Nutr. 58:391–402.
White, P.J. 2016. Selenium accumulation by plants. Ann. Bot. 117:217–235.
White, P.J., Brown, P.H. 2010. Plant nutrition for sustainable development and global health. Ann. Bot. 105:1073–1080.
Zhao, D.Y., Sun, F.L., Zhang, B., Zhang, Z.Q., Yin, L.Q. 2015. Systematic Comparisons of Orthologous Selenocysteine Methyltransferase and Homocysteine Methyltransferase Genes from Seven Monocots Species. Notulae Scientia Biologicae 7:210–216.
Zhu, L., Jiang, C.J., Deng, W.W., Gao, X., Wang, R.J., Wan, X.C. 2007. Cloning and expression of selenocysteine methyltransferase cDNA from Camellia sinensis. Act. Physiol. Plant. 30:167–174.
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Wu, L.J., Shang, Y., Liu, T. et al. Characterization of a Selenium-resistance-enhancing Homocysteine S-methyltransferase from Aegilops tauschii. CEREAL RESEARCH COMMUNICATIONS 46, 263–274 (2018). https://doi.org/10.1556/0806.46.2018.08
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DOI: https://doi.org/10.1556/0806.46.2018.08