Metabolomics Analysis Reveals that Ethylene and Methyl Jasmonate Regulate Different Branch Pathways to Promote the Accumulation of Terpenoid Indole Alkaloids in Catharanthus roseus.

Abstract

The medicinal plant Catharanthus roseus accumulates large numbers of terpenoid indole alkaloids (TIAs), including the pharmaceutically important vinblastine, vincristine, ajmalicine, and serpentine. The phytohormone ethylene or methyl jasmonate (MeJA) can markedly enhance alkaloid accumulation. The interaction between ethylene or MeJA in the regulation of TIA biosynthesis in C. roseus is unknown. Here, a metabolomics platform is reported that is based on liquid chromatography (LC) coupled with time-of-flight mass spectrometry to study candidate components for TIA biosynthesis, which is controlled by ethylene or MeJA in C. roseus. Multivariate analysis identified 16 potential metabolites mostly associated with TIA metabolic pathways and seven targeted metabolites, outlining the TIA biosynthesis metabolic networks controlled by ethylene or MeJA. Interestingly, ethylene and MeJA regulate the 2-C-methyl-d-erythritol 4-phosphate (MEP) and acetate-mevalonate (MVA) pathways through AACT and HMGS and through DXS, respectively, to induce TIA biosynthesis in C. roseus. Overall, both nontargeted and targeted metabolomics, as well as transcript analysis, were used to reveal that MeJA and ethylene control different metabolic networks to induce TIA biosynthesis.