Joint International Research Laboratory of Metabolic and Developmental Sciences, Key Laboratory of Urban Agriculture (South) Ministry of Agriculture, Plant Biotechnology Research Center, Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.
Sci Adv. 2018 Nov 14;4(11):eaas9357. doi: 10.1126/sciadv.aas9357. eCollection 2018 Nov.
produces the valuable medicinal component, artemisinin, which is a sesquiterpene lactone widely used in malaria treatment. AaORA, a homolog of CrORCA3, which is involved in activating terpenoid indole alkaloid biosynthesis in , is a jasmonate (JA)-responsive and trichome-specific APETALA2/ETHYLENE-RESPONSE FACTOR that plays a pivotal role in artemisinin biosynthesis. However, the JA signaling mechanism underlying AaORA-mediated artemisinin biosynthesis remains enigmatic. Here, we report that AaORA forms a transcriptional activator complex with AaTCP14 (TEOSINTE BRANCHED 1/CYCLOIDEA/PROLIFERATING CELL FACTOR 14), which is also predominantly expressed in trichomes. AaORA and AaTCP14 synergistically bind to and activate the promoters of two genes, () and (), both of which encode enzymes vital for artemisinin biosynthesis. AaJAZ8, a repressor of the JA signaling pathway, interacts with both AaTCP14 and AaORA and represses the ability of the AaTCP14-AaORA complex to activate the promoter. JA treatment induces AaJAZ8 degradation, allowing the AaTCP14-AaORA complex to subsequently activate the expression of , which is essential for artemisinin biosynthesis. These data suggest that JA activation of the AaTCP14-AaORA complex regulates artemisinin biosynthesis. Together, our findings reveal a novel artemisinin biosynthetic pathway regulatory network and provide new insight into how specialized metabolism is modulated by the JA signaling pathway in plants.
产生有价值的药用成分青蒿素,这是一种广泛用于疟疾治疗的倍半萜内酯。AaORA 是参与激活 的萜类吲哚生物碱生物合成的 CrORCA3 的同源物,是茉莉酸(JA)响应和毛状体特异性 APETALA2/ETHYLENE-RESPONSE FACTOR,在青蒿素生物合成中发挥关键作用。然而,AaORA 介导的青蒿素生物合成的 JA 信号机制仍然是个谜。在这里,我们报告说 AaORA 与 AaTCP14(TEOSINTE BRANCHED 1/CYCLOIDEA/PROLIFERATING CELL FACTOR 14)形成转录激活复合物,AaTCP14 也主要在毛状体中表达。AaORA 和 AaTCP14 协同结合并激活两个基因的启动子,()和(),这两个基因都编码青蒿素生物合成中至关重要的酶。AaJAZ8 是 JA 信号通路的抑制剂,与 AaTCP14 和 AaORA 相互作用,并抑制 AaTCP14-AaORA 复合物激活 启动子的能力。JA 处理诱导 AaJAZ8 降解,允许随后激活 表达的 AaTCP14-AaORA 复合物,这对青蒿素生物合成是必不可少的。这些数据表明 JA 激活 AaTCP14-AaORA 复合物调节青蒿素生物合成。总之,我们的发现揭示了一个新的青蒿素生物合成途径调控网络,并提供了关于 JA 信号通路如何在植物中调节特化代谢的新见解。