Investigating Useful Microbial Consortia for Degrading Raw andAged MPs

Abstract

Microplastic (MP) contamination in agroecosystems poses a significant threat to soil health, plant growth, and agricultural productivity. The toxicity of MPs increases with aging due to prolonged environmental exposure and surface modifications, leading to greater adverse effects on plant systems. Addressing MP-induced stress is essential for sustainable agriculture and preventing MP entry into the food chain. In this study, we examined the impact of raw and aged MPs on maize (Zea mays) and assessed the efficacy of microbial inoculation using Trichoderma longibrachiatum (TD) and Bacillus subtilis (BS) in mitigating MP-induced stress. Our findings indicate that aged MPs exerted more severe negative effects on plant growth, biomass accumulation, oxidative stress biomarkers, and antioxidant defense mechanisms, including the ascorbate–glutathione (AsA–GSH) cycle and glyoxalase system. However, microbial inoculation significantly improved plant resilience by reducing oxidative stress through enhanced antioxidant enzyme activity, upregulation of stress-responsive genes, and restoration of key defense pathways, ultimately improving plant growth and biomass. Additionally, we investigated how Mitogen-Activated Protein Kinase (MAPK) signaling pathways regulate stress responses by interacting with key molecules and organic acids using an in-silico approach. This aspect provides further insights into the molecular mechanisms underlying plant stress adaptation, which revealed our protein and ligand have strong interaction in MAPK signaling pathways