State Key Laboratory of Crop Genetics and Germplasm Enhancement, Ministry of Agriculture and Rural Affairs Key Laboratory of Biology and Germplasm Enhancement of Horticultural Crops in East China, College of Horticulture, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China.
State Key Laboratory of Crop Genetics and Germplasm Enhancement, Ministry of Agriculture and Rural Affairs Key Laboratory of Biology and Germplasm Enhancement of Horticultural Crops in East China, College of Horticulture, Nanjing Agricultural University, 1 Weigang, Nanjing, 210095, China.
Plant Sci. 2021 Nov;312:111043. doi: 10.1016/j.plantsci.2021.111043. Epub 2021 Aug 28.
ζ-Carotene desaturase (ZDS) is one of the key enzymes regulating carotenoids biosynthesis and accumulation. Celery transgenic efficiency is low and it is difficult to obtain transgenic plants. The study on ZDS was limited in celery. Here, the AgZDS gene was cloned from celery and overexpressed in Arabidopsis thaliana and celery to verify its function. The AgZDS has typical characteristic of ZDS protein and is highly conserved in higher plants. Phylogenetic analysis showed that AgZDS has the closest evolutionary relationship with ZDSs from Solanum lycopersicum, Capsicum annuum and Tagetes erecta. Overexpression of AgZDS gene in A. thaliana and celery resulted in increased accumulations of lutein and β-carotene and up-regulated the expression levels of the genes involved in carotenoids biosynthesis. The contents of lutein and β-carotene in two lines, AtL1 and AgL5, were the highest in transgenic A. thaliana and celery, respectively. The relative expression levels of 5 genes (AtPDS, AtZISO, AtZEP, AtNCED3, and AtCCD4) were up-regulated compared to the wild type plants. The relative expression levels of most genes in carotenoids biosynthesis pathway, such as AgPDS, AgCRTISO1, and AgZISO, were up-regulated in transgenic celery plants. The antioxidant capacity of A. thaliana and photosynthetic capacity of celery were also enhanced. This research is the first report on the function of structure gene related to carotenoid biosynthesis in transgenic celery plants. The findings in this study demonstrated the roles of AgZDS in regulating carotenoids metabolism of celery, which laid a potential foundation for quality improvement of celery.
ζ-胡萝卜素去饱和酶（ZDS）是调控类胡萝卜素生物合成和积累的关键酶之一。芹菜的转基因效率低，难以获得转基因植株。因此，关于 ZDS 的研究在芹菜中受到限制。本研究从芹菜中克隆了 AgZDS 基因，并在拟南芥和芹菜中过表达，以验证其功能。AgZDS 具有 ZDS 蛋白的典型特征，在高等植物中高度保守。系统发育分析表明，AgZDS 与番茄、辣椒和万寿菊的 ZDS 进化关系最密切。AgZDS 基因在拟南芥和芹菜中的过表达导致叶黄素和β-胡萝卜素的积累增加，并上调了参与类胡萝卜素生物合成的基因的表达水平。在转基因拟南芥和芹菜中，两个系 AtL1 和 AgL5 的叶黄素和β-胡萝卜素含量最高。与野生型植物相比，5 个基因（AtPDS、AtZISO、AtZEP、AtNCED3 和 AtCCD4）的相对表达水平上调。类胡萝卜素生物合成途径中的大多数基因（如 AgPDS、AgCRTISO1 和 AgZISO）在转基因芹菜植株中的相对表达水平上调。拟南芥的抗氧化能力和芹菜的光合作用能力也得到了增强。本研究首次报道了与类胡萝卜素生物合成相关的结构基因在转基因芹菜植株中的功能。研究结果表明，AgZDS 在调控芹菜类胡萝卜素代谢中起作用，为芹菜品质改良奠定了潜在基础。
