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Induced production of α-tocotrienol by co-suppression of tocopherol cyclase gene in vegetable crops


Munusamy, Umaiyal and Abdullah, Siti Nor Akmar and Abdul Aziz, Maheran and Khaza'ai, Huzwah and Lai, Mun Seong (2013) Induced production of α-tocotrienol by co-suppression of tocopherol cyclase gene in vegetable crops. American Journal of Biochemistry and Biotechnology, 9 (4). pp. 355-364. ISSN 1553-3468; ESSN: 1558-6332


This study involves the induced production of α-tocotrienol by the co-suppression of tocopherol cyclase gene. The Tocopherol/tocotrienol Cyclase (TC) is a key enzyme involved in the biosynthesis of α-tocotrienol. The partial conserved cDNA of TC gene isolated from the oil palm (Elaeis guineensis) that shared greater than 75% sequence identity with TC sequences from other plant species was used to silence TC gene expression in Amaranthus sp. and Allium porrum leaves by co-suppression strategies. This was carried out using recombinant vector constructs designated as p4a11 and p4c9 containing TC driven by the maize Ubiquitin promoter (Ubi1P) and the oil palm leaf-specific promoter (LHCB), respectively. In the Amaranthus sp. leaves infiltrated with p4a11, the α-tocopherol suppression was 85.0, 71.0 and 74.0% on day three, five and seven, respectively and complete suppression was observed in the leaves infiltrated with p4c9. Whereas, only 11.0, 7.0 and 29.0% suppression was detected in Allium porrum leaves infiltrated with p4a11 and 45.0, 4.0 and 57.0% of suppression was observed in Allium porrum infiltrated with p4c9 on day three, five and seven, respectively. Silencing of TC gene driven by LHCB (p4c9) causes the reduction of α-tocopherol production better than by Ubi1P (p4a11). The results have demonstrated that gene silencing through co-suppression is capable of producing α-tocotrienol. However, there is no correlation between the α-tocotrienol production and the α-tocopherol suppression. It has been suggested that the transgene mediated co-suppression mechanism had triggered the vitamin E biosynthesis metabolic pathway to shift towards producing α-tocotrienol.

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Additional Metadata

Item Type: Article
Divisions: Faculty of Agriculture
Faculty of Medicine and Health Science
Institute of Tropical Agriculture
DOI Number: https://doi.org/10.3844/ajbbsp.2013.355.364
Publisher: Science Publications
Keywords: α-tocopherol; α-tocotrienol; Co-suppression; Tissue-specific promoter; Tocopherol Cyclase; Vitamin E biosynthetic pathway
Depositing User: Raja Norazlinda Raja Azenam
Date Deposited: 27 Dec 2014 13:26
Last Modified: 04 Dec 2017 04:37
Altmetrics: http://www.altmetric.com/details.php?domain=psasir.upm.edu.my&doi=10.3844/ajbbsp.2013.355.364
URI: http://psasir.upm.edu.my/id/eprint/29769
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