Effect of Selenium Hyperaccumulation on the Root Endophytic and Rhizosphere Microbiome of Two Astragalus Species

Heavy metal hyperaccumulation is prevalent throughout plant evolution, particularly in the legume family (Fabaceae), and acts as a presumed chemical defense against herbivory. However, heavy metal hyperaccumulation can have non-target impacts on other biological interactors including plant-microbe interactions. This information is important given the interest in utilizing hyperaccumulating plants for phytoremediation of anthropogenically contaminated soils. Here we employ a greenhouse experiment manipulating selenium level along with 16S rRNA gene amplicon sequencing methods to explore the effect of selenium on the prokaryotic microbiome of the selenium hyperaccumulator Astragalus crotalariae and non-accumulator Astragalus lentiginosus var. borreganus. This project highlights the potential significance of ecological partners in heavy metal accumulating plants and the necessity of their consideration when using these plants for phytoremediation.