玉米β-胡萝卜素羟化酶2基因种子特异性表达的调控机制

项目名称： 玉米β-胡萝卜素羟化酶2基因种子特异性表达的调控机制

项目编号： No.31470394

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 生物科学

项目作者： 朱长甫

作者单位： 长春师范大学

项目金额： 85万元

中文摘要： 类胡萝卜素对人类营养和健康具有重要价值。研究表明玉米种子胚乳类胡萝卜素合成和积累主要是由一些关键类胡萝卜素合成基因（如，玉米八氢番茄红素合酶1和β-胡萝卜素羟化酶2基因）表达调控的。但到目前为止，对玉米种子类胡萝卜素合成基因表达调控机制知之甚少。本项目拟在转基因水稻中对玉米种子特异性表达β-胡萝卜素羟化酶2(BCH2)基因启动子以及与其顺式作用元件特异结合的转录因子进行功能分析和鉴定；在玉米中鉴定超表达或抑制一个或二个转录因子对胚乳等器官内玉米BCH2基因和其它类胡萝卜素合成基因表达以及类胡萝卜素组分和含量的影响；用酵母双杂交、GST Pull-Down和双分子荧光互补技术鉴定克隆的转录因子间的相互作用；揭示克隆和鉴定的转录因子在玉米种子发育过程中对玉米BCH2基因表达和类胡萝卜素组分和含量积累的调控机制，为利用基因工程技术在玉米种子胚乳中生产类胡萝卜素的分子育种提供新的基因源和奠定基础。

中文关键词： 类胡萝卜素；生物合成；转录因子；分子调控；基因克隆

英文摘要： Carotenoids play a critical role in human nutrition and health. It has been demonstrated that carotenoid biosynthesis and accumulation in maize (Zea mays) endosperm are primarily controlled by some key (but not all) carotenogenic gene (e.g. phytoene synthase 1 gene, and non-heme di-iron β-carotene hydroxylase 2 gene) expression. However comparatively little is known about expression regulation of carotenogenic genes which control carotenogenesis in maize endosperm. In this project, the transgenic rice plants will be used to further characterize maize β-carotene hydroxylase 2 (ZmBCH2) gene promoter and transcription factors which specifically recognize and bind to the cis-acting elements of ZmBCH2 gene promoter that controls seed-specific ZmBCH2 gene expression in maize. The overexpression or suppression of one transcription factor gene or two transcription factor genes in transgenic maize plants will be used to analyze simultaneously for endogenous ZmBCH2 gene and other carotenogenic gene expression, as well as carotenoid profiles in different organs and endosperm at different seed developmental stages in order to observe the regulatory mechanisms of ZmBCH2 gene expression controlled by transcription factors. We will carry out Yeast-Two-Hybrid (Y2H) system, GST Pull-Down and Biomolecular Fluorescence Complementation (BiFC) assays to identify the interaction between the isolated transcription factors involved in the regulation of seed-specific gene expression. The anticipated outcomes of proposed project will provide insights into the molecular control mechanisms of ZmBCH2 gene expression and carotenoid accumulation in maize endosperm during seed development. The isolated and characterized seed-specific ZmBCH2 gene promoter and transcription factor genes will be very useful molecular tools for the metabolic engineering of carotenoid accumulation in maize endosperm.

英文关键词： Carotenoids;Biosynthesis;Transcription factor;Molecular regulation;Gene cloning