Comparative analysis of rhizobacterial communities across five medicinal plants in Xinjiang

Five medicinal plants with various therapeutic effects in Xinjiang (Helichrysum thianschanicum Regel, Taraxacum kok-saghyz Rodin, Artemisia rupestris L., Arnebia euchroma Johnst, and Hyssopus officinalis L.) are considered as promising raw materials of pharmaceutical, cosmetic, and fragrance industries. Understanding the characteristics of rhizosphere bacterial communities can be critical in regulating the growth process of these medicinal plants. To clarify the plant-specificity of rhizobacterial assemblages and related driving factors of five medicinal plants, we compared their rhizosphere bacterial communities with those of non-planted soil (CK). Soil physicochemical properties were analyzed, and bacterial communities were characterized using high-throughput sequencing of the 16S rRNA gene V3-V4 region. Results showed that rhizosphere soils of medicinal plants had significantly higher organic matter (OM), total nitrogen (TN), and total phosphorus (TP) than CK, with TP increasing by 2.6-2.9 times. Each medicinal plant rhizosphere harbored a highly specific bacterial community, with unique Amplicon Sequence Variants (ASVs) accounting for 34.04-46.70% of total ASVs, while only 449 core ASVs were shared among all five plants. At the phylum level, Proteobacteria, Bacteroidota, and Acidobacteriota dominated the rhizosphere, in contrast to the dominance of Actinobacteriota in CK. Chitinophagaceae, Sphingomonas, Pseudomonas and RB41 were selectively enriched in different plant rhizospheres. Total potassium (TK), TN, and TP were the key edaphic drivers, with TK negatively correlated with bacterial diversity, and TN/TP regulating the distribution of dominant genera. This study demonstrates high plant-specificity of rhizobacterial communities in Xinjiang medicinal plants and the dominant role of soil TK, TN, and TP, providing a scientific basis for the precise cultivation of medicinal plants and the development of specialized microbial agents.