Search

The fungal endophytes associated with medicinal plants have been demonstrated as a reservoir with novel natural products useful in medicine and agriculture. It is desirable to explore the species composition, diversity and tissue specificity of endophytic fungi that inhabit in different tissues of medicinal plants. In this study, a culture-independent survey of fungal diversity in the rhizosphere, leaves, stems and roots of a toxic medicinal plant, Stellera chamaejasme L., was conducted by sequence analysis of clone libraries of the partial internal transcribed spacer region. Altogether, 145 fungal OTUs (operational taxonomic units), represented by 464 sequences, were found in four samples, of these 109 OTUs (75.2 %) belonging to Ascomycota, 20 (13.8 %) to Basidiomycota, 14 (9.7 %) to Zygomycota, 1 (0.7 %) to Chytridiomycota, and 1 (0.7 %) to Glomeromycota. The richness and diversity of fungal communities were strongly influenced by plant tissue environments, and the roots are associated with a surprisingly rich endophyte community. The endophyte assemblages associated with S. chamaejasme were strongly shaped by plant tissue environments, and exhibited a certain degree of tissue specificity. Our results suggested that a wide variety of fungal assemblages inhabit in S. chamaejasme, and plant tissue environments conspicuously influence endophyte community structure.

This study is the first to describe the composition and characteristics of culturable bacterial isolates from the rhizosphere and bulk soil of the medicinal plant Stellera chamaejasme L. at different growth stages. Using a cultivation-dependent approach, a total of 148 isolates showing different phenotypic properties were obtained from the rhizosphere and bulk soil. Firmicutes and Actinobacteria were the major bacterial groups in both the rhizosphere and bulk soil at all 4 growth stages of S. chamaejasme. The diversity of the bacterial community in the rhizosphere was higher than that in bulk soil in flowering and fruiting stages. The abundance of bacterial communities in the rhizosphere changed with the growth stages and had a major shift at the fruiting stage. Dynamic changes of bacterial abundance and many bacterial groups in the rhizosphere were similar to those in bulk soil. Furthermore, most bacterial isolates exhibited single or multiple biochemical activities associated with S. chamaejasme growth, which revealed that bacteria with multiple physiological functions were abundant and widespread in the rhizosphere and bulk soil. These results are essential (i) for understanding the ecological roles of bacteria in the rhizosphere and bulk soil and (ii) as a foundation for further evaluating their efficacy as effective S. chamaejasme growth-promoting rhizobacteria.