Overexpression of Arabidopsis Homogentisate Phytyltransferase or Tocopherol Cyclase Elevates Vitamin E Content by Increasing γ-tocopherol Level in Lettuce (Lactuca sativa L.)

  • Lee, Koeun ;
  • Lee, Sa Mi ;
  • Park, Sang-Ryoung ;
  • Jung, Jinwook ;
  • Moon, Joon-Kwan ;
  • Cheong, Jong-Joo ;
  • Kim, Minkyun
  • Received : 2007.04.05
  • Accepted : 2007.06.11
  • Published : 2007.10.31


Tocopherols, essential components of the human diet, are synthesized exclusively by photosynthetic organisms. To increase tocopherol content by increasing total flux to the tocopherol biosynthetic pathway, genes encoding Arabidopsis homogentisate phytyltransferase (HPT/V-TE2) and tocopherol cyclase (TC/VTE1) were constitutively overexpressed in lettuce (Lactuca sativa L.). Total tocopherol content of the transgenic plants overexpressing either of the genes was increased by more than 2-fold mainly due to an increase in ${\gamma}$-tocopherol. However, chlorophyll content in the HPT/VTE2 and TC/VTE1 transgenic lines decreased by up to 20% and increased by up to 35%, respectively (P < 0.01). These results demonstrate that manipulation of the tocopherol biosynthetic pathway can increase or decrease chlorophyll content depending on the gene introduced.


Arabidopsis thaliana;Homogentisate Phytyltransferase (HPT/VTE2);Lactuca sativa;Tocopherol;Tocopherol Cyclase (TC/VTE1);Vitamin E


  1. Cho, E. A., Lee, C. A., Kim, Y. S., Baek, S. H., Reyes, B. G., et al. (2005) Expression of ${\gamma}-tocopherol$ methyltransferase transgene improves tocopherol composition in lettuce (Lactuca sativa L.). Mol. Cells 19, 16−22
  2. Kanwischer, M., Porfirova, S., Bergmuller, E., and Dormann, P. (2005) Alterations in tocopherol cyclase activity in transgenic and mutant plants of Arabidopsis affect tocopherol content, tocopherol composition, and oxidative stress. Plant Physiol. 137, 713−723
  3. Kim, Y. J., Seo, H. Y., Park, T. I., Baek, S. H., Shin, W. C., et al. (2005) Enhanced biosynthesis of ${\alpha}-tocopherol$ in transgenic soybean by introducing ${\gamma}-TMT$ gene. J. Plant Biotechnol. 7, 203−209
  4. Murashige, T. and Skoog, F. (1962) A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiol. Plant 15, 473−497
  5. Savidge, B., Weiss, J. D., Wong, Y. H., Lassner, M. W., Mitsky, T. A., et al. (2002) Isolation and characterization of homogentisate phytyltransferase genes from Synechocystis sp. PCC 6803 and Arabidopsis. Plant Physiol. 129, 321−332
  6. Chun, J. Y., Lee, J. S., Ye, L., Exler, J., and Eitenmiller, R. R. (2006) Tocopherol and tocotrienol contents of raw and processed fruits and vegetables in the United States diet. J. Food Comp. Anal. 19, 196−204
  7. Shintani, D. K. and DellaPenna, D. (1998) Elevating the vitamin E content of plants through metabolic engineering. Science 282, 2098−2100
  8. Traber, M. G. and Sies, H. (1996) Vitamin E in humans: demand and delivery. Annu. Rev. Nutr. 16, 321−347
  9. Collakova, E. and DellaPenna, D. (2001) Isolation and functional analysis of homogentisate phytyltransferase from Synechocystis sp. PCC6803 and Arabidopsis. Plant Physiol. 127, 1113−1124
  10. Kumar, R., Raclaru, M., SchuBeler, T., Gruber, J., Sadre, R., et al. (2005) Characterization of plant tocopherol cyclases and their overexpression in transgenic Brassica napus seeds. FEBS Lett. 579, 1357−1364
  11. Kim, J. H. and Botella, J. R. (2004) Etr 1-1 gene expression alters regeneration patterns in transgenic lettuce stimulating root formation. Plant Cell Tiss. Org. 78, 69−73 https://doi.org/10.1023/B:TICU.0000020430.08558.6e
  12. Kamal-Eldin, A. and Appelqvist, L. A. (1996) The chemistry and antioxidant properties of tocopherols and tocotrienols. Lipids 31, 671−701
  13. Rise, M., Cojocaru, M., Gottlieb, H. E., and Goldschmidt, E. E. (1989) Accumulation of ${\alpha}-tocopherol$ in senescing organs as related to chlorophyll degradation. Plant Physiol. 89, 1028−1030
  14. Collakova, E. and DellaPenna, D. (2003) Homogentisate phytyltransferase activity is limiting for tocopherol biosynthesis in Arabidopsis. Plant Physiol. 131, 632−642
  15. DellaPenna, D. and Pogson, B. J. (2006) Vitamin synthesis in plants: tocopherols and carotenoids. Annu. Rev. Plant Biol. 57, 711−738
  16. Shintani, D. K., Cheng, Z., and DellaPenna, D. (2002) The role of 2-methyl-6-phytylbenzoquinone methyltransferase in determining tocopherol composition in Synechocystis sp. PCC6803. FEBS Lett. 511, 1−5
  17. Hirschberg, J. (1999) Production of high-value compounds: carotenoids and vitamin E. Curr. Opin. Biotech. 10, 186−191
  18. Shintani, D. K. (2006) Engineering plants for increased nutrition and antioxidant content through the manipulation of the vitamin E pathway. Genet. Eng. 27, 231−242
  19. Cheng, Z., Sattler, S., Maeda, H., Sakuragi, Y., Bryant, D. A., et al. (2003) Highly divergent methyltransferases catalyze a conserved reaction in tocopherol and plastoquinone synthesis in Cyanobacteria and photosynthetic eukaryotes. Plant Cell 15, 2343−2356
  20. Kim, B. K., Park, S. Y., Jeon, B. Y., Hwang, D. Y., and Min, B. W. (2004) Metabolic engineering increased vitamin C levels in lettuce by overexpression of a $L-gulono-{\gamma}-lactone$ oxidase. J. Kor. Soc. Hort. Sci. 45, 16−20
  21. DellaPenna, D. (2005) A decade of progress in understanding vitamin E synthesis in plants. J. Plant Physiol. 162, 729−737
  22. Grusak, M. A. (1999) Genomics-assisted plant improvement to benefit human nutrition and health. Trends Plant Sci. 4, 164− 166
  23. DellaPenna, D. and Last, R. L. (2006) Progress in the dissection and manipulation of plant vitamin E biosynthesis. Physiol. Plantarum 126, 356−368
  24. Eenennaam, A. L., Lincholn, K., Durrett, T. P., Valentin, H. E., Shewmaker, C. K., et al. (2003) Engineering vitamin E content: From Arabidopsis mutant to soy oil. Plant Cell 15, 3007−3019
  25. Porfirova, S., Bergmuller, E., Tropf, S., Rainer, L., and Dormann, P. (2002) Isolation of an Arabidopsis mutant lacking vitamin E and identification of a cyclase essential for all tocopherol biosynthesis. Proc. Natl. Acad. Sci. USA 99, 12495−12500
  26. Arnon, D. I. (1949) Copper enzymes in isolated chloroplasts polyphenoloxidase in Beta vulgaris. Plant Physiol. 24, 1−15
  27. Wroblewski, T., Tomczak, A., and Michelmore, R. (2005) Optimization of Agrobacterium-mediated transient assays of gene expression in lettuce, tomato and Arabidopsis. Plant Biotechnol. J. 3, 259−273


Supported by : Korean Ministry of Science and Technology