Cadmium (Cd) contamination poses a significant threat to agroecosystems and food security by impairing soil health, triggering oxidative stress in plants, and reducing crop productivity. Sustainable approaches combining biocompatible biochar (BC) with nanoparticles (NPs) for Cd immobilization and soil-plant-microbe restoration require further exploration. This study evaluates the effectiveness of BC, nano-silicon (nSi), and nano-iron (nFe) in mitigating Cd toxicity, enhancing soil quality, and regulating maize stress responses in Cd-contaminated soil. The bioavailability of Cd, soil microbial communities, and maize transcriptomic profiles were assessed under different BC-nSi-nFe treatments.

Results: The composite treatment BC + 25% nSi + 75% nFe + Cd (T6) significantly reduced bioavailable Cd by 21%, increased soil pH from 6.21 to 6.98, and boosted soil enzyme activity by 118–139%. Additionally, T6 improved maize biomass by 115–119%, decreased Cd accumulation in shoots by 78%, and lowered oxidative stress markers (67–75% reduction in ROS). Transcriptomic analysis revealed that BC-NPs composites alleviate Cd-induced stress by modulating maize antioxidant defenses and phytohormone signaling pathways, providing novel insights into the molecular basis of enhanced plant resilience. Soil microbial communities shifted toward metal-resistant species, with increased glutathione metabolism and nitrogen fixation.

Muhammad Umair Yasin (Ph.D.) is a Postdoctoral Fellow at Zhejiang University, China, specializing in green engineering of nanoparticles for Nano-biotechnology and phytoremediation. He completed his Ph.D. in Crop Genetics and Breeding at Zhejiang University. His research integrates nanotechnology, soil microbiology, and plant molecular biology to develop sustainable solutions for soil contamination and crop resilience. He has published over 20 articles in high-impact (>100) journals (including Journal of Hazardous Materials, Science of The Total Environment) and secured competitive grants, including the China Postdoctoral Science Foundation. He has vast experience in nano-engineering for improving plant resilience by gene and phytohormone regulation in crops.