Special Microbial cmmunity sturucture formed by Taraxacum koksaghyz Rodin rhizosphere soil in Extreme Saline and Alkaline Environments

Taraxacum koksaghyz Rodin (TKS), known as Russian dandelion, represents a promising alternative source of natural rubber and demonstrates remarkable tolerance to saline–alkaline stress. However, the mechanisms underlying its adaptation to extreme soil conditions remain largely unexplored. In this study, we investigated the rhizosphere microbial community structure of wild TKS populations inhabiting saline–alkaline soils of tekec and Zhaosu Counties in Xinjiang, China. Soil physicochemical parameters and microbial diversity were characterized using high-throughput sequencing of bacterial 16S rRNA and fungal ITS regions. The results revealed pronounced heterogeneity between the two regions: Zhaosu soils exhibited higher salinity and alkalinity but also greater nutrient availability (OM and TN), while tekec soils were relatively less saline but nutrient-poor. Bacterial communities were dominated by Bacillus, Actinomarinales, and Geminicoccaceae, whereas Mortierella, Fusarium, and Metarhizium prevailed among fungi. Increasing salinity significantly reduced bacterial richness and evenness, yet favored dominance of halotolerant taxa. Redundancy and correlation analyses indicated that Na ⁺ , Cl ⁻ , and SO₄²⁻ were the primary drivers of bacterial community shifts, while fungal assemblages were more strongly influenced by Ca²⁺, Mg²⁺, HCO₃⁻, and organic matter. These findings suggest that microbial adaptation in TKS rhizospheres is shaped by a complex interplay between ion composition and nutrient availability. The co-enrichment of halophilic Bacillus and stress-resistant fungi such as Mortierella likely contributes to TKS’s resilience under salinity stress, providing a potential microbial resource for developing bioinoculants suited to saline–alkaline agriculture.