Heavy metal pollution decreases the stability of microbial co-occurrence networks in the rhizosphere of native plants

Abstract

Soil microorganisms play an important role in maintaining soil quality and function, although the response of soil microbial biodiversity to heavy metals has been extensively investigated, the microbe-microbe associations under the influence of both native plant species and extremely high heavy metal contamination are not well documented. We examined the diversity and composition of microbial communities and the physicochemical properties in the rhizosphere of three native plant species, Carex breviculmis, Buddleja davidii, and Artemisia annua growing on and around a Pb-Zn waste heap with a nearly 100-year history of natural recovery. Both plant species and heavy metals influence soil microbial diversity and composition. C. breviculmis and A. annua showed a prominent advantage in increasing rhizosphere microbial diversity and richness as well as network complexity compared with plant Buddleja davidii at severely contaminated soil, which was mainly related to the accumulation of soil nutrients such as soil organic carbon (SOC), total nitrogen ammonium nitrogen and nitrate nitrogen rather than a reduction in heavy metal concentrations. Moreover, the heavy metal concentration and soil nutrient levels significantly affected the microbial groups affiliated with Proteobacteria, Chloroflexi, Ascomycota, and Basidiomycota, in which those affiliated with Chloroflexi and Ascomycota were positively associated with heavy metals. Soil microbial network on the Pb-Zn waste heap exhibited higher average degree and a higher proportion of positive links than those around the waste heap, and thus soil microbial structure became more complexity and unstable with increasing heavy metal pollution.

Regulation of soil nutrient cycling in the root zone of Pyracantha fortuneana: The role of core microbiome induced by plant species

“…The findings indicate that the HB and HY treatments exhibit greater network complexity (more nodes and edges) compared to the other treatments, potentially due to increased resource constraints (reduction of carbon and nutrients), thereby enhancing the network complexity of microorganisms. This aligns with previous studies that found microorganisms strengthen connections among themselves to form more complex networks for improved growth in relatively nutrient‐poor soils (Faust & Raes, 2012; Sun et al., 2022). The number of positive and negative junctions reflects the intensity of potential cooperation and competition among microbial communities, respectively.…”

Unraveling the role of contaminants reshaping the microflora in Zea mays seeds from heavy metal-contaminated and pristine environment

“…This suggests that environmental stressors, such as HM contamination, signi cantly in uence endophytic community dynamics, leading to changes in both diversity and abundance. This nding aligns with the research by Sun, Wu [19], which showed that HM, like copper (Cu), plays a crucial role in shaping fungal diversity in contaminated environments. Our ndings corroborated those of the study of Xie, Fan [20], which demonstrated that HM pollution causes changes in the makeup of microbial communities.…”