Abstract

Background and aims Ulex europaeus L. (Fabaceae), commonly known as gorse, is an invasive woody shrub that easily grows in several locations across the world. However, little is known about the interactions of this invasive species with soil microorganisms and how these microbes can promote rapid grow-rates at early stages of development. We aim to explore this by characterizing the endophytic fungal and bacterial microbiota associated with roots of juvenile U. europaeus plants colonizing native ecosystems in south-central Chile. Methods Root-associated microorganisms were isolated and identified using standard molecular techniques. Furthermore, plant growth-promoting traits and biocontrol activity of the isolates against phytopathogenic fungi were assessed to characterize the early growth stage root-associated taxa. Results Four endophytic fungi belonging to Sordariomycetes and twelve bacteria assigned to Proteobacteria and Actinobacteria were associated with the early stage of U. europaeus. Plant growth-promoting traits were detected in some isolates such as Fusarium acuminatum and Rhodococcus sp. Additionally, two endophyte isolates Rhodococcus sp. and Purpureocillium lilacinum showed biocontrol potential against phytopathogenic fungi tested in this study. Conclusions Our results demonstrate that U. europaeus plantlets host several endophytes in the roots, some of which showed biocontrol capabilities and plant growth-promoting traits that can contribute with the rapid growth-rates at juvenile stages of the shrub. The interaction with a set of endophytes demonstrating these beneficial traits is an additional mechanism explaining the ability of U. europaeus to colonize various ecosystems.