Jasmonate promotes artemisinin biosynthesis by activating the TCP14-ORA complex in Artemisia annua

Sci Adv. 2018 Nov 14;4(11):eaas9357. doi: 10.1126/sciadv.aas9357. eCollection 2018 Nov.

Abstract

Artemisia annua 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 Catharanthus roseus, 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, double bond reductase 2 (DBR2) and aldehyde dehydrogenase 1 (ALDH1), 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 DBR2 promoter. JA treatment induces AaJAZ8 degradation, allowing the AaTCP14-AaORA complex to subsequently activate the expression of DBR2, 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Artemisia annua / drug effects
  • Artemisia annua / growth & development
  • Artemisia annua / metabolism*
  • Artemisinins / metabolism*
  • Biosynthetic Pathways / drug effects*
  • Cyclopentanes / pharmacology*
  • Gene Expression Regulation, Plant / drug effects*
  • Oxylipins / pharmacology*
  • Plant Growth Regulators / pharmacology
  • Plant Proteins / genetics
  • Plant Proteins / metabolism*
  • Protein Interaction Domains and Motifs / drug effects*

Substances

  • Artemisinins
  • Cyclopentanes
  • Oxylipins
  • Plant Growth Regulators
  • Plant Proteins
  • jasmonic acid