Bo Wei ^1,2 Qianqian Xu ^2* Junfei Kong ^1* Xu Su ^3* Kelong Chen ^4* Hengsheng Wang ^5*

• ¹ School of Biology, Food and Environmen, Hefei University, Hefei, China
• ² ational Engineering Laboratory of Crop Stress Resistance Breeding, Anhui Agricultural University, Hefei, China
• ³ National Positioning Observation and Research Station of the Qinghai Lake Wetland Ecosystem in Qinghai Province, Nation al Forestry and Grassland Administration, Haibei Tibetan Autonomous Prefecture, China
• ⁴ Key Laboratory of Biodiversity Formation Mechanism and Comprehensive Utilization of the Qinghai-Tibet Plateau in Qinghai Province, Qinghai Normal University, Xining, China
• ⁵ School of Food and Biological Engineering, Hefei University of Technology, Hefei, Anhui Province, China

Poa alpigena L. is a dominant forage grass widely distributed on the Tibetan Plateau and is often used in livestock production and replanting of degraded grasslands. Studies have shown that rhizospheric microorganisms play an important role in plant growth and reproduction, but there have been few studies on rhizospheric microorganisms of P. alpigena L. We performed metagenomic sequencing of rhizospheric and non-rhizospheric soil microorganisms of Poa alpigena L. from Ganzi River, to establish a soil microbial gene pool of P. alpigena L. in the Qinghai Lake basin. The results showed that the soil microorganisms of P. alpigena L. belonged to 5,681 species in 1,606 genera, 521 families, 61 phyla, and 246 orders. ALPHA diversity analysis showed that the species richness of nonrhizospheric microorganisms of P. alpigena L. was higher than that of rhizospheric microorganisms. The difference in abundance of dominant microorganisms in the two soils was minor, and the phylum Proteobacteria accounted for the largest proportion in both types of soils. Furthermore, Stamp and Lefse analysis revealed that the level of difference between rhizosphere and non-rhizosphere soils exhibited variations from phylum to family. For example, the abundance of Ascomycota, Pseudomonadace, and Burkholderiaceae in the rhizosphere soil (GZG) group was significantly higher than the non-rhizosphere soil (GZC) group, whereas the abundance of Alphaproteobacteria and Caulobacterales was significantly high in the GZC group. The significant enrichment of rhizospheric microorganisms with pathways such as biosynthesis of antibiotics, carbon metabolism and methane metabolism may provide an important approach for mitigating and controlling elevated methane levels and suppressing global warming. In contrast, the pathways involved in non-rhizosphere microorganisms were dominated by quorum sensing, lysosomes, and drug-metabolizing cytochrome P450. Correlation analysis of the abundance of dominant microorganisms in all soil samples revealed a mutual inhibiting or promoting relationship between different species of microorganisms.