Overexpression of the Maize γ-tocopherol Methyltransferase Gene (ZmTMT) Increases α-tocopherol Content in Transgenic Arabidopsis and Maize Seeds

Overview

Journal Transgenic Res

Specialty Molecular Biology

Date 2019 Nov 2

PMID 31673914

Citations 6

Authors

Lan Zhang

Yanzhong Luo

Bin Liu

Liang Zhang

Wei Zhang

Rumei Chen

Lei Wang

Affiliations

Soon will be listed here.

Abstract

The vitamin E family includes tocopherols and tocotrienols, which are essential lipid-soluble antioxidants necessary for human and livestock health. The seeds of many plant species, including maize, have high gamma (γ)-tocopherol but low alpha (α)-tocopherol contents; however, α-tocopherol is the most effective antioxidant. Therefore, it is necessary to optimize the tocopherol composition in plants. α-Tocopherol is synthesized from γ-tocopherol by γ-tocopherol methyltransferase (γ-TMT, VTE4) in the final step of the tocopherol biosynthetic pathway. In the present study, the full-length coding sequence (CDS) of γ-TMT was isolated from Zea mays, named ZmTMT. The ZmTMT CDS was 1059 bp in size, encoding 352 amino acids. Recombinant ZmTMT was expressed in Escherichia coli and the purified protein effectively converted γ-tocopherol into α-tocopherol in vitro. A comparison of enzyme activities showed that the activity of ZmTMT was higher than that of GmTMT2a (Glycine max) and AtTMT (Arabidopsis thaliana). Overexpression of ZmTMT increased the α-tocopherol content 4-5-fold in transgenic Arabidopsis and around 6.5-fold in transgenic maize kernels, and increased the α-/γ-tocopherol ratio to approximately 15 and 17, respectively. These results show that it is feasible to overexpress ZmTMT to optimize the tocopherol composition in maize; such a corn product might be useful in the feed industry in the near future.

Citing Articles

Calcium and Magnesium Regulation of Kernel Sugar Content in Maize: Role of Endogenous Hormones and Antioxidant Enzymes.

He Z, Shang X, Jin X, Wang X, Xing Y Int J Mol Sci. 2025; 26(1.

PMID: 39796058 PMC: 11719980. DOI: 10.3390/ijms26010200.

Heterologous Expression of Sunflower and Genes Enhances Rice-Grain Vitamin E Content.

Song S, Li H, Lin S, Dong X, Tian R, Wu Z Plants (Basel). 2024; 13(17).

PMID: 39273875 PMC: 11397534. DOI: 10.3390/plants13172392.

A Summary of Two Decades of QTL and Candidate Genes That Control Seed Tocopherol Contents in Maize ( L.).

Kassem M, Knizia D, Meksem K Genes (Basel). 2024; 15(4).

PMID: 38674406 PMC: 11049817. DOI: 10.3390/genes15040472.

ROS scavenging and ion homeostasis is required for the adaptation of halophyte to high salinity.

Li C, Mur L, Wang Q, Hou X, Zhao C, Chen Z Front Plant Sci. 2022; 13:979956.

PMID: 36262663 PMC: 9574326. DOI: 10.3389/fpls.2022.979956.

Assessment of Biofortification Approaches Used to Improve Micronutrient-Dense Plants That Are a Sustainable Solution to Combat Hidden Hunger.

Koc E, Karayigit B J Soil Sci Plant Nutr. 2021; 22(1):475-500.

PMID: 34754134 PMC: 8567986. DOI: 10.1007/s42729-021-00663-1.

References

Cho E, Lee C, Kim Y, Baek S, de Los Reyes B, Yun S . Expression of gamma-tocopherol methyltransferase transgene improves tocopherol composition in lettuce (Latuca sativa L.). Mol Cells. 2005; 19(1):16-22. View

Diepenbrock C, Kandianis C, Lipka A, Magallanes-Lundback M, Vaillancourt B, Gongora-Castillo E . Novel Loci Underlie Natural Variation in Vitamin E Levels in Maize Grain. Plant Cell. 2017; 29(10):2374-2392. PMC: 5774569. DOI: 10.1105/tpc.17.00475. View

Tavva V, Kim Y, Kagan I, Dinkins R, Kim K, Collins G . Increased alpha-tocopherol content in soybean seed overexpressing the Perilla frutescens gamma-tocopherol methyltransferase gene. Plant Cell Rep. 2006; 26(1):61-70. DOI: 10.1007/s00299-006-0218-2. View

Wang H, Xu S, Fan Y, Liu N, Zhan W, Liu H . Beyond pathways: genetic dissection of tocopherol content in maize kernels by combining linkage and association analyses. Plant Biotechnol J. 2018; 16(8):1464-1475. PMC: 6041443. DOI: 10.1111/pbi.12889. View

Lipka A, Gore M, Magallanes-Lundback M, Mesberg A, Lin H, Tiede T . Genome-wide association study and pathway-level analysis of tocochromanol levels in maize grain. G3 (Bethesda). 2013; 3(8):1287-99. PMC: 3737168. DOI: 10.1534/g3.113.006148. View

Collakova E, DellaPenna D . Homogentisate phytyltransferase activity is limiting for tocopherol biosynthesis in Arabidopsis. Plant Physiol. 2003; 131(2):632-42. PMC: 166839. DOI: 10.1104/pp.015222. View

Munne-Bosch S, Falk J . New insights into the function of tocopherols in plants. Planta. 2003; 218(3):323-6. DOI: 10.1007/s00425-003-1126-0. View

DellaPenna D . Progress in the dissection and manipulation of vitamin E synthesis. Trends Plant Sci. 2005; 10(12):574-9. DOI: 10.1016/j.tplants.2005.10.007. View

dHarlingue A, Camara B . Plastid enzymes of terpenoid biosynthesis. Purification and characterization of gamma-tocopherol methyltransferase from Capsicum chromoplasts. J Biol Chem. 1985; 260(28):15200-3. View

10.

Arun M, Subramanyam K, Theboral J, Sivanandhan G, Rajesh M, Dev G . Transfer and targeted overexpression of γ-tocopherol methyltransferase (γ-TMT) gene using seed-specific promoter improves tocopherol composition in Indian soybean cultivars. Appl Biochem Biotechnol. 2013; 172(4):1763-76. DOI: 10.1007/s12010-013-0645-9. View

11.

Soll J, Schultz G . Comparison of geranylgeranyl and phytyl substituted methylquinols in the tocopherol synthesis of spinach chloroplasts. Biochem Biophys Res Commun. 1979; 91(3):715-20. DOI: 10.1016/0006-291x(79)91939-9. View

12.

Shutu X, Dalong Z, Ye C, Yi Z, Shah T, Ali F . Dissecting tocopherols content in maize (Zea mays L.), using two segregating populations and high-density single nucleotide polymorphism markers. BMC Plant Biol. 2012; 12:201. PMC: 3502391. DOI: 10.1186/1471-2229-12-201. View

13.

Li Q, Yang X, Xu S, Cai Y, Zhang D, Han Y . Genome-wide association studies identified three independent polymorphisms associated with α-tocopherol content in maize kernels. PLoS One. 2012; 7(5):e36807. PMC: 3352922. DOI: 10.1371/journal.pone.0036807. View

14.

Arita M, Sato Y, Miyata A, Tanabe T, Takahashi E, KAYDEN H . Human alpha-tocopherol transfer protein: cDNA cloning, expression and chromosomal localization. Biochem J. 1995; 306 ( Pt 2):437-43. PMC: 1136538. DOI: 10.1042/bj3060437. View

15.

Van Eenennaam A, Lincoln K, Durrett T, Valentin H, Shewmaker C, Thorne G . Engineering vitamin E content: from Arabidopsis mutant to soy oil. Plant Cell. 2003; 15(12):3007-19. PMC: 282849. DOI: 10.1105/tpc.015875. View

16.

Chung Y, Mahan D, Lepine A . Efficacy of dietary D-alpha-tocopherol and DL-alpha-tocopheryl acetate for weanling pigs. J Anim Sci. 1992; 70(8):2485-92. DOI: 10.2527/1992.7082485x. View

17.

Karunanandaa B, Qi Q, Hao M, Baszis S, Jensen P, Wong Y . Metabolically engineered oilseed crops with enhanced seed tocopherol. Metab Eng. 2005; 7(5-6):384-400. DOI: 10.1016/j.ymben.2005.05.005. View

18.

Clough S, Bent A . Floral dip: a simplified method for Agrobacterium-mediated transformation of Arabidopsis thaliana. Plant J. 1999; 16(6):735-43. DOI: 10.1046/j.1365-313x.1998.00343.x. View

19.

Seo Y, Kim S, Harn C, Kim W . Ectopic expression of apple fruit homogentisate phytyltransferase gene (MdHPT1) increases tocopherol in transgenic tomato (Solanum lycopersicum cv. Micro-Tom) leaves and fruits. Phytochemistry. 2011; 72(4-5):321-9. DOI: 10.1016/j.phytochem.2010.12.013. View

20.

Zhang L, Luo Y, Zhu Y, Zhang L, Zhang W, Chen R . GmTMT2a from soybean elevates the α-tocopherol content in corn and Arabidopsis. Transgenic Res. 2013; 22(5):1021-8. DOI: 10.1007/s11248-013-9713-8. View