Endophytic bacterial diversity of the medicinal orchid Dendrobium nobile

Abstract

As a valuable medicinal epiphyte of Orchidaceae, Dendrobium nobile is widely utilized in Asian medicine. Despite the importance of Mycorrhizae in the germination of Dendrobium seeds, little is known about its endophytic microbiome. In the present study, 16S rRNA high-throughput sequencing is therefore applied to investigate the endophytic bacterial community structure associated with the different vegetative organs (roots, stems and leaves) of D. nobile. A total of 24 bacterial phyla and 448 genera of endophytes were identified, with Proteobacteria, Actinobacteria, and Acidobacteria being the dominant phyla. The relative abundance and diversity of endophytes in roots are found to be generally higher than those in stems and leaves. Most of the endophytes are predicted to be involved in nutrient metabolism, and some bacterial taxa are found to be involved in the recruitment of genera from the same phylum. Overall, the study provided important insights into the community structure and functional characteristics of endophytes in D. nobile, and lay a theoretical foundation for a better understanding of the interactive dialog between medicinal plants and their endophytes.