P2

Linking Populus nigra metabotypes to genetic variation and plant-herbivore interactio

Black poplar (Populus nigra) is rich in specialised metabolites, making it a prime candidate for the study of plant-herbivore interactions. During the first funding period, the chemical diversity and phenotypic plasticity of black poplar leaves in response to feeding by Lymantria dispar were investigated, focusing on volatile and non-volatile metabolites and genotype-dependent changes in gene expression in response to feeding. The results so far indicate that terpene emissions and the effects of feeding on metabolic composition vary between genotypes and are influenced by bioclimatic and geographical factors. 

In the second funding period, we will focus on the analysis of chemodiversity in different poplar tissues (leaves of different ages, roots, phloem and xylem) and building a 'metabolic atlas' to map metabolic networks. This approach is in line with previous work on poplar transcriptome networks in the context of heat/drought stress memory. Building on this, we will investigate intraspecific chemodiversity and plasticity in black poplar organs and tissues under different abiotic and biotic conditions, focusing on drought stress and above and below ground herbivory. The project will employ non-target metabolomics to understand the metabolic basis of these responses. It is hypothesised that drought stress alters plant-herbivore dynamics through changes in resource allocation, leading to organ-specific adaptations of metabolomic networks. Joint chemodiversity-plasticity experiments will be conducted with all partners of the RU in the climate chambers of Helmholtz Munich to comparatively analyse metabolic adaptation mechanisms in black poplar, tansy and bittersweet nightshade to understand the overall role of chemodiversity in stress adaptation.