Simultaneous expression of Arabidopsis ρ-hydroxyphenylpyruvate dioxygenase and MPBQ methyltransferase in transgenic corn kernels triples the tocopherol content

Departament de Producció Vegetal i Ciència Forestal, Universitat de Lleida, 25198, Lleida, Spain.
Transgenic Research (Impact Factor: 2.32). 02/2011; 20(1):177-81. DOI: 10.1007/s11248-010-9393-6
Source: PubMed


The quantity and composition of tocopherols (compounds with vitamin E activity) vary widely among different plant species reflecting the expression, activity and substrate specificity of enzymes in the corresponding metabolic pathway. Two Arabidopsis cDNA clones corresponding to ρ-hydroxyphenylpyruvate dioxygenase (HPPD) and 2-methyl-6-phytylplastoquinol methyltransferase (MPBQ MT) were constitutively expressed in corn to further characterize the pathway and increase the kernel tocopherol content. Transgenic kernels contained up to 3 times as much γ-tocopherol as their wild type counterparts whereas other tocopherol isomers remained undetectable. Biofortification by metabolic engineering offers a sustainable alternative to vitamin E supplementation for the improvement of human health.

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Available from: Changfu Zhu, Mar 24, 2015
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    • "The combined expression of HPPD and MPBQ-MT resulted in a threefold increase in c-tocopherol levels without changing the total tocopherol content (Naqvi et al., 2011b). These experiments again showed that flux was directed into the a-branch but in this case it was blocked by low c–TMT activity, forcing the accumulation of c–tocopherol (Naqvi et al., 2011b). "
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