Trichoderma viride F7 improves peanut performance while remedying cadmium-contaminated soil with microplastics

Microplastics (MPs) and cadmium (Cd) in the soil have serious negative impacts on plant growth. As a bioremediator, Trichoderma viride may modulate the impacts of MPs or/and Cd on plant growth and heavy metal uptake. In this study, T. viride F7 (F7) was used to treat Cd-contaminated soil with or without polylactic acid MPs (PLA-MPs) to investigate its effects on peanut growth, Cd uptake efficiency, and soil properties. The results showed that F7 increased the soil pH, dissolved organic carbon (DOC), cation exchange capacity (CEC), microbial nitrogen (MBN), and microbial carbon (MBC), which resulted in a 2.10–19.83% increase in peanut biomass and mitigated the negative effects of PLA and Cd on peanut growth. F7 reduced the soil effective-state Cd and plant Cd content by 16.68–34.20% and 5.37–25.84%, respectively. Regression path analysis showed that F7 could improve peanut performance by altering soil properties and reducing peanut Cd concentrations in PLA-MP- and Cd-contaminated soils. Soil fungal community analysis indicated that the microbial community was altered via F7 inoculation, which antagonized Fusarium and promoted peanut growth. This study reveals the mechanism of F7 in mitigating Cd contamination in soil in the presence of MPs, which provides new ideas for managing complex contaminated soil with MP–heavy metals and improving soil health.