Phosphatidylcholine is a major phospholipid which is shown to be involved in stress adaptation. Phosphatidylcholine increased during dehydration in Craterostigma plantagineum, and therefore we characterized CTP:phosphocholine cytidylyltransferase (CpCCT1), a key regulatory enzyme for phosphatidylcholine synthesis in plants. The CpCCT1 gene from the resurrection plant C. plantagineum was cloned and the amino acid sequence was compared with homologs from other species including yeast and rat. CCT proteins have conserved catalytic and membrane-binding domains while the N-terminal and C-terminal domains have diverged. The tissue specific expression analysis indicated that CpCCT1 is expressed in all tested tissues and it is induced by dehydration and in response to 0.5 M NaCl solutions. In plants exposed to low temperature in the dark, the CpCCT1 transcript increased after 4 h at 4 °C. CpCCT1 expression also increased during mannitol and sorbitol treatments in a concentration dependent manner. Phytohormones such as abscisic acid and indole-3-acetic acid also trigged transcript accumulation. Comparisons of transcript and protein accumulations for different treatments (except for dehydration) suggest transcriptional and translational control mechanisms. Analysis of promoter activity and polysome occupancy suggest that CpCCT1 gene expression is mainly under translational regulation during dehydration.

中文翻译：

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CTP:磷酸胆碱胞苷转移酶CpCCT1在车前草复活植物中的鉴定和表征

磷脂酰胆碱是一种主要的磷脂，被证明与压力适应有关。车前草脱水期间磷脂酰胆碱增加，因此我们表征了 CTP：磷酸胆碱胞苷转移酶 (CpCCT1)，这是植物中磷脂酰胆碱合成的关键调节酶。来自复活植物车前草的 CpCCT1 基因被克隆，并将氨基酸序列与其他物种（包括酵母和大鼠）的同源物进行比较。CCT 蛋白具有保守的催化和膜结合结构域，而 N 端和 C 端结构域已经分化。组织特异性表达分析表明，CpCCT1 在所有测试组织中均有表达，并且由脱水和对 0.5 M NaCl 溶液的响应诱导。在黑暗中暴露于低温的植物中，CpCCT1 转录本在 4°C 下 4 小时后增加。CpCCT1 表达也在甘露醇和山梨醇处理期间以浓度依赖性方式增加。脱落酸和吲哚-3-乙酸等植物激素也会触发转录物的积累。不同处理（脱水除外）的转录物和蛋白质积累的比较表明转​​录和翻译控制机制。启动子活性和多核糖体占有率的分析表明，CpCCT1 基因表达主要在脱水过程中受翻译调控。不同处理（脱水除外）的转录物和蛋白质积累的比较表明转​​录和翻译控制机制。启动子活性和多核糖体占有率的分析表明，CpCCT1 基因表达主要在脱水过程中受翻译调控。不同处理（脱水除外）的转录物和蛋白质积累的比较表明转​​录和翻译控制机制。启动子活性和多核糖体占有率的分析表明，CpCCT1 基因表达主要在脱水过程中受翻译调控。