Volatile profile of Echinacea purpurea plants after in vitro endophyte infection.

The differences in volatile profile of Echinacea purpurea plants not-inoculated (EpC) and inoculated with their endophytes from roots (EpR) and stem/leaves (EpS/L) were analysed and compared by GC-FID/GC-MS in an in vitro model. Non-terpenes and sesquiterpene hydrocarbons were the most abundant classes with an opposite behaviour of EpS/L showing a decreased emission of sesquiterpenes and an increase of non-terpene derivatives. The main compounds obtained from EpS/L were (Z)-8-dodecen-1-ol and 1-pentadecene, while germacrene D and ß-caryophyllene were the key compounds in EpC and EpR. For the first time, this work indicates that bacterial endophytes modify the aroma profiles of infected and non-infected in vitro plants of the important medicinal plant E. purpurea. Therefore, our model of infection could permit to select endophytic strains to use as biotechnological tool in the production of medicinal plants enriched in volatile bioactive compounds.