Lycopene ε-cyclases (LCYEs) are key enzymes in carotenoid biosynthesis converting red lycopene to downstream lutein. The flowers of marigold (Tagetes erecta) have been superior sources to supply lutein. However, the transcriptional regulatory mechanisms of LCYe in lutein synthesis are still unclear in marigold. In this work, the expression pattern of the TeLCYe gene in marigold indicated that TeLCYe mainly expressed in floral organs. To gain a better understanding of the expression and regulatory mechanism of TeLCYe gene, the TeLCYe promoter was isolated, sequenced, and analyzed through bioinformatics tools. The results suggested that the sequence of TeLCYe promoter contained various putative cis-acting elements responsive to exogenous and endogenous factors. The full-length TeLCYe promoter and three 5'-deletion fragments were fused to the GUS reporter gene and transferred into tobacco to test the promoter activities. A strong GUS activity was observed in stems of seedlings, leaves of seedlings, middle stems, top leaves, petals, stamens, and stigmas in transgenic tobacco containing full-length TeLCYe promoter LP0-2086. Deletion of - 910 to - 429 bp 5' to ATG significantly increased the GUS activity in chloroplast-rich tissues and floral organs, while deletion occurring from 1170 to 910 bp upstream ATG decreased the TeLCYe promoter strength in stems of seedlings, leaves of seedlings, top leaves and sepals. Functional characterization of the full-length TeLCYe promoter and its' deletion fragments in stable transgenic tobacco indicated that the LP0-2086 contains some specific cis-acting elements, which might result in the high-level expression of in floral organs, and LP2-910 might contain some specific cis-acting elements which improved GUS activities in vegetable tissues.

中文翻译：

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转基因烟草中万寿菊（万寿菊）番茄红素ε-环化酶（TeLCYe）启动子的功能分析。


番茄红素 ε-环化酶 (LCYE) 是将红色番茄红素转化为下游叶黄素的类胡萝卜素生物合成中的关键酶。万寿菊花是提供叶黄素的优质来源。然而，万寿菊中LCYe在叶黄素合成中的转录调控机制仍不清楚。本工作中TeLCYe基因在万寿菊中的表达模式表明TeLCYe主要在花器官中表达。为了更好地了解TeLCYe基因的表达和调控机制，通过生物信息学工具对TeLCYe启动子进行分离、测序和分析。结果表明，TeLCYe 启动子序列包含各种推定的对外源和内源因子敏感的顺式作用元件。将全长TeLCYe启动子和三个5'-缺失片段与GUS报告基因融合并转移到烟草中以测试启动子活性。在含有全长TeLCYe启动子LP0-2086的转基因烟草中，在苗茎、苗叶、中部茎、顶部叶、花瓣、雄蕊和柱头中观察到强烈的GUS活性。 ATG 5'- 910 至 - 429 bp 的缺失显着增加了叶绿体丰富的组织和花器官中的 GUS 活性，而 ATG 上游 1170 至 910 bp 的缺失则降低了幼苗茎、幼苗叶、顶部的叶子和萼片。稳定转基因烟草中全长 TeLCYe 启动子及其缺失片段的功能表征表明，LP0-2086 含有一些特定的顺式作用元件，这可能导致 LP2-910 在花器官中高水平表达。可能含有一些特定的顺式作用元件，可以提高植物组织中的 GUS 活性。