PDF(Pubmed)
Abstract：
Sterols play important structural and regulatory roles in numerous intracellular processes. Unlike animals, plants contain a distinctive and diverse variety of sterols. Recently, information has emerged showing that stigmasterol is a \"stress sterol\". Stigmasterol is synthesized via the mevalonate biosynthesis pathway and has structural similarity to β-sitosterol but differs in the presence of a trans-oriented double bond in the side chain. In plants, the accumulation of stigmasterol has been observed in response to various stresses. However, the precise ways that stigmasterol is involved in the stress responses of plants remain unclear. This comprehensive review provides an update on the biology of stigmasterol, particularly the physicochemical properties of this ethylsterol, its biosynthesis, and its occurrence in higher plants and extremophilic organisms, e.g., mosses and lichens. Special emphasis is given to the evolutionary aspects of stigmasterol biosynthesis, particularly the variations in the gene structure of C22-sterol desaturase, which catalyzes the formation of stigmasterol from β-sitosterol, in a diversity of evolutionarily distant organisms. The roles of stigmasterol in the tolerance of plants to hostile environments and the prospects for its biomedical applications are also discussed. Taken together, the available data suggest that stigmasterol plays important roles in plant metabolism, although in some aspects, it remains an enigmatic compound.
摘要：
甾醇在许多细胞内过程中起着重要的结构和调节作用。与动物不同,植物含有独特多样的甾醇。最近,有信息显示，豆甾醇是一种“应激甾醇”。豆甾醇是通过甲羟戊酸生物合成途径合成的，与β-谷甾醇具有结构相似性，但不同的是在侧链中存在反式取向的双键。在植物中,已观察到豆甾醇在各种胁迫下的积累。然而,豆甾醇参与植物胁迫反应的确切方式仍不清楚。这篇全面的综述提供了对豆甾醇生物学的最新研究，特别是这种乙基甾醇的物理化学性质，它的生物合成，以及它在高等植物和极端生物中的发生，例如，苔藓和地衣。特别强调豆甾醇生物合成的进化方面，特别是C22-甾醇去饱和酶基因结构的变异，催化β-谷甾醇形成豆甾醇，在进化上遥远的生物的多样性中。还讨论了豆甾醇在植物对恶劣环境的耐受性中的作用及其生物医学应用前景。一起来看,现有数据表明，豆甾醇在植物代谢中起着重要作用，虽然在某些方面,它仍然是一个神秘的化合物。
