CLONING AND EXPRESSION OF CAROTENOID BIOSYNTHETIC GENES

转座子标记是一种非常有效的分离方法， 编码未知产物的基因座 将使用这种方法 分离出玉米和番茄的类胡萝卜素基因， 生物合成途径 类胡萝卜素是色素， 在植物光保护中的重要作用。 类胡萝卜素也是 作为维生素A的前体在人类和动物中是必需的， 防止光敏反应的保护剂。 类胡 生物合成是相当好地理解从生物化学 许多类胡萝卜素突变体的分析。 玉米中的类胡萝卜素突变体， vp-5和番茄中的一种类胡萝卜素突变体ghost积累了相同的量 类胡萝卜素前体，八氢番茄红素。 为了启动对 基因调控和表达，将克隆玉米vp-5基因座 通过转座子标记。 虽然转座因子没有 在番茄中被发现，我们将尝试引入克隆 玉米转座因子在T-DNA载体上导入番茄 通过感染农杆菌传播。 换位 将被选择并用于克隆 的基因。

Transposon tagging is a very powerful approach for isolating genetic loci encoding unknown products. This approach will be used to isolate maize and tomato genes involved in the carotenoid biosynthetic pathway. Carotenoids are pigments which play an important role in photoprotection in plants. Carotenoids are also essential in humans and animals as precursors of vitamin A and protective agents against photosensitive reactions. Carotenoid biosynthesis is fairly well understood from the biochemical analysis of many carotenoid mutants. A carotenoid mutant in maize, vp-5, and a carotenoid mutant in tomato, ghost, accumulate the same carotenoid precursor, phytoene. In order to initiate studies of gene regulation and expression, the maize vp-5 locus will be cloned by transposon tagging. Although transposable elements have not been discovered in tomato, we will attempt to introduce the cloned maize transposable element into tomato on engineered T-DNA vectors to be transmitted by infection with Agrobacterium. Transpositions into the tomato ghost locus will be selected and used for cloning of the gene.