Agricultural Biotechnology Department, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran.
Agronomy and Plant Breeding Department, Faculty of Agriculture, Shahrood University of Technology, Semnan, Iran.
Phytochem Anal. 2020 Mar;31(2):229-241. doi: 10.1002/pca.2887. Epub 2019 Aug 30.
Throughout history, thousands of medicinal and aromatic plants have been widely utilised by people worldwide. Owing to them possessing of valuable compounds with little side effects in comparison with chemical drugs, herbs have been of interest to humans for a number of purposes. Diosgenin, driven from fenugreek, Trigonella foenum-graecum L., has extensively drawn scientist's attention owing to having curable properties and being a precursor of steroid hormones synthesis. Nonetheless, complete knowledge about the biosynthesis pathway of this metabolite is still elusive.
In the present research, we isolated the full-length CDS of 14 genes involving in diosgenin formation and measured their expression rate in various genotypes, which had illustrated different amount of diosgenin.
The genes were successfully isolated, and functional motifs were also assessed using in silico approaches.
Moreover, combining transcript and metabolite analysis revealed that there are many genes playing the role in diosgenin formation, some of which are highly influential. Among them, ∆ -reductase, which converts cycloartenol to cycloartanol, is the first-committed and rate-limiting enzyme in this pathway. Additionally, no transcripts indicating to the presence or expression of lanosterol synthase were detected, contradicting the previous hypothesis about the biosynthetic pathway of diosgenin in fenugreek.
Considering all these, therefore, we propose the most possible pathway of diosgenin. This knowledge will then pave the way toward cloning the genes as well as engineering the diosgenin biosynthesis pathway.
纵观历史,全世界有数千种药用和芳香植物被广泛应用。由于其所含的化合物具有比化学药物更小的副作用,草药一直是人类关注的焦点,具有多种用途。薯蓣皂素是从胡芦巴中提取的,具有治疗特性,是甾体激素合成的前体,因此,三角叶薯蓣被广泛关注。然而,关于这种代谢物生物合成途径的完整知识仍然难以捉摸。
在本研究中,我们分离了涉及薯蓣皂素形成的全长 CDS,并测量了它们在不同基因型中的表达率,这些基因型表现出不同含量的薯蓣皂素。
成功分离了这些基因,并使用计算机方法评估了它们的功能基序。
此外,结合转录物和代谢物分析表明,有许多基因在薯蓣皂素形成中发挥作用,其中一些基因具有高度影响力。在这些基因中,将环阿屯醇转化为环阿坦醇的 ∆-还原酶是该途径中的第一个关键酶和限速酶。此外,没有检测到表明存在或表达羊毛甾醇合酶的转录本,这与之前关于胡芦巴中薯蓣皂素生物合成途径的假设相矛盾。
因此,考虑到所有这些因素,我们提出了薯蓣皂素最可能的生物合成途径。这一知识将为克隆基因以及工程化薯蓣皂素生物合成途径铺平道路。