Elicitation effects of methyl jasmonate on secoiridoid production in shoot culture of centaury (Centaurium erythraea Rafn)

Abstract

Centaurium erythraea (centaury), a plant with a long tradition of medicinal use, contains bioactive secoiridoid glucosides (SGs). The exogenous application of methyl jasmonate (MeJA) may elicit a response similar to stress, and is used in the present study to induce SG accumulation and expression of SGs’ biosynthesis associated genes in centaury’s aerial parts. UHPLC-MS/MS analyses have indicated that the addition of 250 μM MeJA to the medium has caused overproduction of almost all investigated secondary metabolites. The most notable change was detected for swertiamarin production, which was several fold-higher in MeJA-treated plants. For the purpose of determining the key genes of MeJA response, we performed a qPCR analysis of all genes potentially involved in the secoiridoid biosynthetic pathway. After five days of MeJA treatment, an increase of relative gene expression was detected for G8O, 8HGO7, IO, 7DLGT, 7DLH2, SLS and CPR1. On the other hand, in centaury plants subjected to MeJA treatment for ten days, there was no significant increase in gene expression. For GPPS and LAMT, decreased expression levels were detected, when compared to control plants. Patterns of SGs biosynthetic gene expression are highly correlated to SGs’ profiles during MeJA-elicitation treatments, giving clear evidence that the identified genes are a part of SGs’ biosynthetic routes. All the results indicate that MeJA is a suitable elicitor that leads, through gene expression changes, to increased flux through the pathway and production of swertiamarin, sweroside and gentiopicrin, which can be used for future production of secoiridoids with the aid of biotechnological processes.