Differences in rhizosphere soil microbial function and community structure in invasive weed Bidens pilosa and native weeds

As an invasive weed, Bidens pilosa seriously threatens native ecosystem functions in beach regions in South China. This study aimed to explore the differences in soil nutrients and microorganisms between the invasive weed B. pilosa and native weeds (Cynodon dactylon, Portulaca oleracea, and Eleusine indica), exploring variations in soil functions after B. pilosa invasion. The results showed that soil nutrients varied by the weed species. The total and unique bacterial and fungal amplicon sequence variant (ASV) numbers in B. pilosa were higher than those in the other three weeds. The bacterial composition related to soil carbon metabolism differed between B. pilosa and the other three native weeds. Analysis of bacterial metabolic pathways showed that their soil carbon metabolism ability was higher than that of the other three native weeds. Some pathogenic fungi and Lophotrichus (dark septate endophytes) are enriched in the rhizosphere of B. pilosa. Increasing the relative abundance of beneficial soil bacteria and decreasing the relative abundance of pathogenic soil fungi may be beneficial for resisting the invasion of B. pilosa. In addition, the soil total phosphorus, available phosphorus, and soil organic matter contents were identified as the most important edaphic factors shaping microbial community structure and function in the context of B. pilosa invasion. This study revealed differences in soil microorganisms between B. pilosa and native weeds, and these differences potentially affected the native ecosystem function.