拟南芥2-甲基-6-叶绿基-1,4-苯醌甲基转移酶启动子的分离及表达特性分析

Isolation and Characterization of 2-methyl-6-phytyl-1, 4-benzoquinol Methyltransferase Gene Promoter from Arabidopsis thaliana

摘要:

维生素E是一类人体必需的脂溶性抗氧化剂, 具有重要的生理功能。2-甲基-6-叶绿基-1,4-苯醌甲基转移酶(MPBQ MT)是天然维生素E合成途径中的关键酶之一, 催化MPBQ甲基化, 生成DMPBQ。从拟南芥分离了MPBQ MT基因1018bp的启动子序列, 构建了含该启动子和GUS报告基因的植物表达载体, 通过农杆菌介导转化拟南芥, 获得了转基因植株。GUS组织化学染色结果表明, 在MPBQ MT启动子驱动下, 报告基因GUS在拟南芥的茎、叶、花萼、雄蕊、种荚均有表达, 且在茎、叶、种荚中表达量较高, 而在根、花瓣和种子中则没有观察到GUS基因的表达, 表明MPBQ MT基因可能仅在拟南芥幼嫩茎、叶、种荚等绿色组织中特异性高表达。

Abstract:

Vitamin E, or tocopherol, is a lipid-soluble antioxidant and essential for human health. 2-methyl-6-phytyl-1, 4-benzo- quinol methyltransferase (MPBQ MT), one of the key enzymes in vitamin biosynthetic pathway in plants, converts 2-methyl- 6-phytyl-1,4-benzoquinol(MPBQ) to 2,3-dimethyl-6-phytyl-1,4-benzoquinol (DMPBQ).In this study, we isolated the 1018bp promoter of Arabidopsis MPBQ MT gene. The promoter was fused with GUS reporter gene and this expression cassette was introduced into wild Arabidopsis by Agrobacterium-mediated transformation. GUS staining shows that GUS gene was expressed in stems, leaves, calyxes, stamens and siliques in transgenic Arabidopsis plants, with higher expression in green tissue such as stems, leaves, siliques, while invisible in roots, petals, and seeds. The data indicate that MPBQ MT gene promoter was likely to be expressed preferentially in green tissues such as stems, leaves, and young siliques.