PDF(Pubmed)
Abstract：
As one of the largest and most diverse classes of specialized metabolites in plants, terpenoids (oprenoid compounds, a type of bio-based material) are widely used in the fields of medicine and light chemical products. They are the most important secondary metabolites in coniferous species and play an important role in the defense system of conifers. Terpene synthesis can be promoted by regulating the expressions of terpene synthase genes, and the terpene biosynthesis pathway has basically been clarified in Pinus massoniana, in which there are multiple rate-limiting enzymes and the rate-limiting steps are difficult to determine, so the terpene synthase gene regulation mechanism has become a hot spot in research. Herein, we amplified a PmDXR gene (GenBank accession no. MK969119.1) of the MEP pathway (methyl-erythritol 4-phosphate) from Pinus massoniana. The DXR enzyme activity and chlorophyll a, chlorophyll b and carotenoid contents of overexpressed Arabidopsis showed positive regulation. The PmDXR gene promoter was a tissue-specific promoter and can respond to ABA, MeJA and GA stresses to drive the expression of the GUS reporter gene in N. benthamiana. The DXR enzyme was identified as a key rate-limiting enzyme in the MEP pathway and an effective target for terpene synthesis regulation in coniferous species, which can further lay the theoretical foundation for the molecularly assisted selection of high-yielding lipid germplasm of P. massoniana, as well as provide help in the pathogenesis of pine wood nematode disease.
摘要：
作为植物中最大和最多样化的特殊代谢物之一，萜类化合物(类阿片化合物，一种生物基材料）广泛用于医药和轻化产品领域。它们是针叶树种最重要的次生代谢产物，在针叶树的防御系统中起着重要作用。通过调节萜类合成酶基因的表达可以促进萜类合成,马尾松萜烯生物合成途径已基本阐明,其中有多种限速酶，限速步骤难以确定，因此萜类合成酶基因调控机制成为研究热点。在这里，我们扩增了一个PmDXR基因(GenBank登录号。MK969119.1）来自马尾松的MEP途径（甲基赤藓糖醇4-磷酸）。DXR酶活性与叶绿素a,过表达拟南芥的叶绿素b和类胡萝卜素含量呈正调控。PmDXR基因启动子是一个组织特异性启动子，可以响应ABA，MeJA和GA胁迫驱动GUS报告基因在N.benthamiana中的表达。DXR酶被确定为MEP途径中的关键限速酶，是针叶树种萜烯合成调控的有效靶标，为分子辅助筛选马尾松高产脂质种质奠定了理论基础,以及为松材线虫病的发病提供帮助。
