文献类型： 外文期刊

作者： Jiang, Jishan ¹ ; Jia, Huili ¹ ; Feng, Guangyan ¹ ; Wang, Zan ¹ ; Li, Jun ¹ ; Gao, Hongwen ¹ ; Wang, Xuemin ¹ ;

作者机构： 1.Chinese Acad Agr Sci, Inst Anim Sci, 2 Yuanmingyuan West Rd, Beijing 100193, Peoples R China

2.Shanxi Acad Agr Sci, Anim Husb & Vet Inst, Taiyuan 030032, Peoples R China

3.Sichuan Agr Univ, Coll Anim Sci & Technol, Dept Grassland Sci, Wenjiang 611130, Peoples R China

4.Chinese Acad Agr Sci, Inst Grassland Res, Hohhot 010020, Peoples R China

关键词： Vitamin E;gamma-tocopherol methyltransferase;transgenic alfalfa;osmotic stress tolerance;alpha-tocopherol;leaf senescence

期刊名称：PLANT SCIENCE （ 影响因子：4.729； 五年影响因子：5.132 ）

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收录情况： SCI

摘要： Alfalfa (Medicago sativa L.) is a major forage legume for livestock and a target for improving their dietary quality. Vitamin E is an essential vitamin that animals must obtain from their diet for proper growth and development. gamma-tocopherol methyltransferase (gamma-TMT), which catalyzes the conversion of delta- and gamma-tocopherols (or tocotrienols) to beta- and alpha-tocopherols (or tocotrienols), respectively, is the final enzyme involved in the vitamin E biosynthetic pathway. The overexpression of M. sativa L.'s gamma-TMT (MsTMT) increased the alpha-tocopherol content 10-15 fold above that of wild type Arabidopsis seeds without altering the total content of vitamin E. Additionally, in response to osmotic stress, the biomass and the expression levels of several osmotic marker genes were significantly higher in the transgenic lines compared with wild type. Overexpression of MsTMT in alfalfa led to a modest, albeit significant, increase in alpha-tocopherol in leaves and was also responsible for a delayed leaf senescence phenotype. Additionally, the crude protein content was increased, while the acid and neutral detergent fiber contents were unchanged in these transgenic lines. Thus, increased alpha-tocopherol content occurred in transgenic alfalfa without compromising the nutritional qualities. The targeted metabolic engineering of vitamin E biosynthesis through MsTMT overexpression provides a promising approach to improve the alpha-tocopherol content of forage crops. (C) 2016 The Authors. Published by Elsevier Ireland Ltd. This is an open access article under the CC BY-NC-ND license.