Assembly of endophytic communities of Setaria viridis L. plants when grown in different soils and derived from different seeds

The association of the plant microbiota is a successional process that starts with the seed and its intrinsic microbiota. The recently reported relevance of seeds as carriers of microbiota has encouraged investigations of the assembly of these communities in different tissues. Here, we address the contributions of both seed and soil bacterial microbiota in the assembly of communities within endospheres of adult plants by 16S rRNA gene-based Illumina sequencing. Surface-sterilized seeds of the model plant Setaria viridis L. were sown in sterile conditions and seedlings were transferred onto either their native soil or a foreign soil. Soil-derived bacterial colonizers contributed to the highest portion of endophytic microbiota, with varying community composition depending on the cultivation soil. In contrast, the contribution of seed microbiota in those of adult plants was less evident. Moreover, seedlings grown in their native soils resulted in plants with consistent endophytic assemblages, whereas a dramatic increase in variability was observed for rhizosphere and endophytic root communities of plants grown in foreign soils.