Effect of AM Fungi Inoculation on Litter Bacterial Community Characteristics under Heavy Metal Stress

Abstract

Because microorganisms are the primary driving force behind litter decomposition, they play an important role in maintaining ecosystem material and chemical cycling. Arbuscular mycorrhizal (AM) fungi can improve host plant tolerance to various environmental stressors, making their application in mining area remediation important. In this study, litter from the dominant plant species (Imperata cylindrica) in a copper tailings mining area was selected as the experimental material. We conducted a greenhouse-based heavy metal stress experiment to investigate how AM fungi affect litter microbial community characteristics and key ecological factors. Results showed that AM fungi species, heavy metal treatments, and their combined interaction had significant impacts on litter pH. Additionally, enzyme activities in litter were significantly affected by interactions between AM fungi species and heavy metal contaminates. Ralstonia was significantly positively correlated to lead (Pb) content, indicating that Ralstonia had a certain tolerance to Pb pollution. Sucrase and urease activity were increased when plants were inoculated with Rhizophagus irregularis under Pb stress. Furthermore, Microbacterium, Brevundimonas, and Pseudonocardia all may play important roles in litter decomposition, while a certain tolerance was observed in Kushneria and Roseivivax to heavy metal pollution when plants were inoculated with Glomus mosseae. Results showed that AM fungi affected litter bacterial community structure and function by influencing plant litter properties. By exploring interactions between AM fungi and bacterial communities in plant litter under heavy metal stress, we will better understand associative processes that promote the cycling of soil organic matter and nutrients contaminated by non-ferrous metal tailings.

Potential use of indigenous arbuscular mycorrhizal fungi to improve soil productivity in tailing of tin mining: a greenhouse study scale

“…Furthermore, the existence Imperata cylindrica found in some spot area in post-tin mining site may become hostplant for AMF. I. cylindrica is a perennial grass species that is known for its ability to form extensive underground networks of symbiotic AMF [19]. Acaulospora sp.…”

The mechanism of promoting rhizosphere nutrient turnover for arbuscular mycorrhizal fungi attributes to recruited functional bacterial assembly

“…One study has indicated that AM fungi may influence bacterial community assembly processes during litter decomposition (Nuccio et al, 2013). AM fungi affected microbial community characteristics by influencing litter properties and enzyme activities, especially some key microbiomes (Jia et al, 2022). Another study showed that Actinobacteria in the rhizosphere was promoted by AM fungi ( R. intraradices ) and led to the less extractable metal ion in Cd in contaminated soil (Chen, Wu, et al, 2019).…”

“…Several studies have reported that bacterial community interacts with AM fungi in the rhizosphere (Sangwan & Prasanna, 2022). For example, AM fungi attract microorganisms associated with litter decomposition to colonize litter and promote litter decomposition (Jia et al, 2022). Changes in the chemical composition of root exudates from AM-associated plants as well as shifts in nutrient sources for associated bacteria can also affect rhizosphere bacterial communities (Zhang et al, 2022).…”

Rhizosphere Microbial Communities and Geochemical Constraining Mechanism of Antimony Mine Waste-Adapted Plants in Southwestern China

“…As the main decomposer and carbon sequester in soil, fungi can maintain soil fertility and health, and play an important ecological role in the ecosystem [ 27 , 28 , 29 ]. Jia et al [ 30 ] found that arbuscular mycorrhizal fungi changed the oxidation of heavy metals and bacterial community structure in rhizosphere soil, reducing the bioavailability of heavy metals.…”