FWF - Asteraceae - Bridging metabolome and microbiome diversification in Asteraceae medicinal plants

The plant microbiome has been extensively studied in recent years, whereby a variety of plant-microbe interactions that are essential for growth and health of the host plant were discovered. However, the majority of these interactions and functions, such as the impact of the microbiome on the metabolome, are poorly understood. Plants use metabolites to shape and direct their associated microbial communities; however, there is some evidence that, vice versa, the plant-associated microorganisms influence the metabolic fingerprint of their host plant, leading to different metabolic phenotypes. The overall objective of the project is to experimentally investigate the possibility to direct the plant’s chemical profile via plant-associated microorganisms. Studies concerning correlations between microbial communities and plant metabolites will be conducted on two Asteraceae medicinal plants, the German chamomile (Matricaria chamomilla L.) and the pot marigold (Calendula officinalis L.). These plant species were selected as suitable model plants for these studies because of their rich secondary metabolism with particularly high levels of flavonoids, sesquiterpenes, and triterpenes, their known diversification in chemical profiles, and their cultivation and medicinal utilization all over the world. An interconnected experimental design enables (i) to analyze the effect of the soil microbiome on the plant metabolome, (ii) the development of a model for predicting metabolite production, (iii) targeted inoculation experiments to verify correlations, and (iv) to elucidate the functional linkage of the rhizosphere microbiome by a metagenomic study. A multi-phasic approach exploiting novel “meta-omics” technologies will be used to deeply analyze plants grown in natural ecosystems as well as in specifically developed in vitro systems. Promising correlations will be evaluated in detail under strictly controlled conditions. We aim to elucidate the linkage of the plant microbiome and metabolome in order to improve the plants’ usability as bioresource for compounds with therapeutic and biotechnological relevancy.