Abstract
α-Tocopherol, the most biologically active form of vitamin E, is implicated in decreasing the risk of several types of cancers, coronary heart disease and a number of degenerative human conditions, when taken in excess of the recommended daily allowance. Natural α-tocopherol has twice the bioavailability of the synthetic isomer. This study describes a successful attempt at fortifying human diets with natural α-tocopherol by taking recourse to genetic engineering of an important oilseed crop, Brassica juncea. γ-Tocopherol methyl transferase cDNA from Arabidopsis thaliana, coding for the enzyme catalysing the conversion of the large γ-tocopherol pool to α-tocopherol, was overexpressed in B. juncea plants. The successful integration of the transgene was confirmed by PCR and Southern blot analysis, while the enhanced transcript level was evident in the northern blot analysis. HPLC analysis of the seeds of the T1 transgenic lines showed a shift in tocopherol profile with the highest over-expressors having α-tocopherol levels as high as sixfold over the non-transgenic controls. This study discusses the production of a transgenic oilseed crop with high α-tocopherol levels, which can provide a feasible, innocuous, and inexpensive way of taking the beneficial effects of high α-tocopherol intake to the masses.
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References
Ajjawi I, Shintani D (2004) Engineered plants with elevated vitamin E: a nutraceutical success story. Trends Biotechnol 22:104–107
Bramley PM, Elmadfa I, Kafatos A, Kelly FJ, Manios Y, Roxborough HE, Schuch W, Sheehy PJA, Wagner KH (2000) Vitamin E. J Sci Food Agric 80:913–938
Brigelius-Flohe R, Traber MG (1999) Vitamin E: function and metabolism. FASEB J 13:1145–1155
Cahoon EB, Hall SE, Ripp KG, Ganzke TS, Hitz WD, Coughlan SJ (2003) Metabolic redesign of vitamin E biosynthesis in plants for tocotrienol production and increased antioxidant content. Nat Biotechnol 21(9):1081–1087
Cho EA, Lee CA, Kim YS, Baek SH, de los Reyes BG, Yun SJ (2005) Expression of γ-tocopherol methyl transferase transgene improves tocopherol composition in lettuce (Latuca sativa L.). Mol Cells 19(1):16–22
Collakova E, DellaPenna D (2003) Homogentisate phytyltransferase activity is limiting for tocopherol biosynthesis in Arabidopsis. Plant Physiol 131:632–642
Estevez JM (2001) 1-Deoxy-d-xylulose-5-phosphate synthase, a limiting enzyme for plastidic isoprenoid biosynthesis in plants. J Biol Chem 276:22901–22909
Falk J, Andersen G, Kernebeck B, Krupinska K (2003) Constitutive overexpression of barley 4-hydroxyphenylpyruvate dioxygenase in tobacco results in elevation of vitamin E content in seeds but not in leaves. FEBS Lett 540:35–40
Munné-Bosch S, Alegre L (2002) The functions of tocopherols and tocotrienols in plants. Crit Rev Plant Sci 21:31–57
Pental D, Pradhan AK, Sodhi YS, Mukhopadhayaya A (1993) Variation amongst Brassica juncea cultivars for regeneration from hypocotyl explants and optimization of conditions for Agrobacterium mediated genetic transformation. Plant Cell Rep 12:462–467
Sattler SE, Gilliland LU, Magallanes-Lundback M, Pollard M, DellaPenna D (2004) Vitamin E is essential for seed longevity and for preventing lipid peroxidation during germination. Plant Cell 16:1419–1432
Savidge B, Weiss JD, Wong YHH, Lassner MW, Mitsky TA, Shewmaker CK, Post-Beittenmiller D, Valentin HE (2002) Isolation and characterization of homogentisate phytyl transferase genes from Synechocystis sp. PCC 6803 and Arabidopsis. Plant Physiol 129:321–322
Shintani D, DellaPenna D (1998) Elevating the vitamin E content of plants through metabolic engineering. Science 282:2098–2100
Taylor P, Barnes P (1981) Analysis of vitamin E in edible oils by high performance liquid chromatography. Chem Ind (Oct. 17):722–726
Traber MG, Sies H (1996) Vitamin E in humans: demand and delivery. Annu Rev Nutr 16:321
Tsegaye Y, Shintani DK, DellaPenna D (2002) Overexpression of the enzyme p-hydroxyphenyl pyruvate dioxygenase in Arabidopsis and its relationship to tocopherol biosynthesis. Plant Physiol Biochem 40:913–920
Van-Eenennaam AL, Lincoln K, Durrett TP, Valentin HE, Shewmaker CK, Thorne GM, Jiang J, Baszis SR, Levering CK, Aasen ED, Hao M, Stein JC, Norris SR, Last RL (2003) Engineering vitamin E content: from Arabidopsis mutant to soy oil. Plant Cell 15(12):3007–3019
Acknowledgements
We are thankful to ABRC, Ohio State University, for the γ-TMT cDNA. Prof. Syed. Akhtar Husain, Department of Biosciences, Jamia Millia Islamia, New Delhi, is acknowledged for allowing the use of the HPLC facility. Seeds of B. juncea were a kind gift from Dr Shyam Prakash, I.A.R.I., New Delhi. We are thankful to Profs Nirmala and S.C. Maheshwari and Prof. S.K. Sopory, I.C.G.E.B., New Delhi and Prof. Santosh Misra, University of Victoria, Canada, for their valuable critical comments. M.A.Y. was a recipient of junior and senior research fellowships from U.G.C., India. Funding from C.S.I.R., India (Grant No. 38/1126/EMR-II), is thankfully acknowledged.
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Yusuf, M.A., Sarin, N.B. Antioxidant value addition in human diets: genetic transformation of Brassica juncea with γ-TMT gene for increased α-tocopherol content. Transgenic Res 16, 109–113 (2007). https://doi.org/10.1007/s11248-006-9028-0
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DOI: https://doi.org/10.1007/s11248-006-9028-0