Bacterial Community Structure and FEAST Source Tracking of Endophytes in Vernonia anthelmintica (L.) Willd. from Southern Xinjiang, China

Using 16S rRNA gene amplicon sequencing and FEAST microbial source tracking, this study characterized the bacterial communities in tissues (roots, stems, leaves, seeds) and associated soils (rhizosphere and bulk soil) of <i>Vernonia anthelmintica</i>, an important Uyghur medicinal plant endemic to arid southern Xinjiang. We found significantly higher bacterial diversity in soil than in plant tissues, with <i>Pseudomonadota</i>-dominated plant-associated communities and Actinobacteria co-dominating in soils. Bacterial community structures varied across plant compartments, with soil communities exhibiting greater stability and broader niche breadth. Critically, FEAST source tracking revealed that rhizosphere soil contributed 23.8%, 13.4%, 17.9%, and 10.8% of the bacterial communities in roots, stems, leaves, and seeds, respectively, identifying soil as the primary source of endophytic bacteria. These findings highlight the pivotal role of arid-region soil microbial diversity in shaping the unique endophytic microbiome of V. anthelmintica, providing a scientific basis for conserving soil microbial health to support its standardized cultivation and sustainable utilization in Uyghur medicine.