Department of Metabolic and Structural Biology, CSIR-Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), Lucknow, 226015, India.
School of Interdisciplinary and Applied Sciences, Central University of Haryana, Jant-Pali, Mahendragarh, Haryana, 123031, India.
Planta. 2022 Jun 1;256(1):4. doi: 10.1007/s00425-022-03912-4.
Overexpression of a novel geranylgeranyl pyrophosphate synthase gene (WsGGPPS) in planta resulted in increased levels of gibberellic acid and decrease in withanolide content. Withania somnifera (L.) Dunal, the herb from family Solanaceae is one of the most treasured medicinal plant used in traditional medicinal systems owing to its unique stockpile of pharmaceutically active secondary metabolites. Phytochemical and pharmacological studies in this plant were well established, but the genes affecting the regulation of biosynthesis of major metabolites were not well elucidated. In this study cloning and functional characterization of a key enzyme in terpenoid biosynthetic pathway viz. geranylgeranyl pyrophosphate synthase (EC 2.5.1.29) gene from Withania somnifera was performed. The full length WsGGPPS gene contained 1,104 base pairs that encode a polypeptide of 365 amino acids. The quantitative expression analysis suggested that WsGGPPS transcripts were expressed maximally in flower tissues followed by berry tissues. The expression levels of WsGGPPS were found to be regulated by methyl jasmonate (MeJA) and salicylic acid (SA). Amino acid sequence alignment and phylogenetic studies suggested that WsGGPPS had close similarities with GGPPS of Solanum tuberosum and Solanum pennellii. The structural analysis provided basic information about three dimensional features and physicochemical parameters of WsGGPPS protein. Overexpression of WsGGPPS in planta for its functional characterization suggested that the WsGGPPS was involved in gibberellic acid biosynthesis.
在植物体内过表达一种新型的香叶基香叶基焦磷酸合酶基因（WsGGPPS）导致赤霉素水平升高，而缬草内酯含量降低。茄科植物睡茄（L.）Dunal 是一种最珍贵的药用植物，由于其独特的药用活性次生代谢物库存，在传统医学系统中被广泛使用。该植物的植物化学和药理学研究已经得到很好的建立，但影响主要代谢物生物合成调节的基因尚未得到很好的阐明。在这项研究中，从睡茄中克隆和功能表征了萜类生物合成途径中的一个关键酶，即香叶基香叶基焦磷酸合酶（EC 2.5.1.29）基因。全长 WsGGPPS 基因包含 1104 个碱基对，编码 365 个氨基酸的多肽。定量表达分析表明，WsGGPPS 转录物在花组织中表达最高，其次是浆果组织。发现 WsGGPPS 的表达水平受茉莉酸甲酯（MeJA）和水杨酸（SA）调节。氨基酸序列比对和系统发育研究表明，WsGGPPS 与马铃薯和马铃薯近缘种的 GGPPS 具有密切相似性。结构分析提供了关于 WsGGPPS 蛋白三维特征和物理化学参数的基本信息。为了对 WsGGPPS 进行功能表征，在植物体内过表达 WsGGPPS 表明 WsGGPPS 参与了赤霉素的生物合成。
