Datasets for supplementary figures 1-5, Transcriptome assembly and selected sequences for qPCR primer design used in the paper: "The endomicrobiome and weed invasiveness in Mediterranean ecosystems"

Mediterranean ecosystems, one of the most significant global hotspots of biodiversity, are threatened by invasive weeds. Although endomicrobiomes – the vast array of microbes colonising living plant tissues – are known to affect plant fitness, their contribution to weed invasiveness remains virtually unknown. Here we experimentally assessed the role of the endomicrobiome in the microevolution of Taraxacum officinale (common dandelion), a widespread invasive weed in Mediterranean ecosystems worldwide. In a culling experiment across five generations, we compared the microevolutionary rates of T. officinale from Mediterranean ecosystems on five continents grown with intact or reduced native seed-borne endomicrobiomes. Additionally, we conducted a competition experiment with F1 and F5 individuals to assess their impacts on native local Asteraceae species. We found T. officinale individuals growing with their intact endomicrobiomes to exhibit faster and more positive trait evolution than individuals growing with reduced endomicrobiomes. Enhanced competitiveness of endomicrobiome-colonized T. officinale plants with local Asteraceae species was apparently caused by increased synthesis of allelochemicals in shoots and rhizosphere soil, with gene expression analyses also showing the endomicrobiome to affect the expression by T. officinale of stress response and RNA-directed DNA methylation genes. Our findings provide novel insights into the mechanisms underlying weed invasiveness in Mediterranean ecosystems, highlighting the endomicrobiome as a potent driving force in the evolutionary processes associated with plant invasion success.