Soil heavy metal contamination poses a global threat to ecosystem health. Although biochar is a known amendment for immobilising such contaminants, its capacity to proactively enhance the intrinsic resilience of soil fauna remains poorly understood. In this study, ants ( Formica japonica ) were biochar-conditioned with biochar before exposure to heavy metals, and their physiology, heavy metal accumulation, stress and social behaviours, and transcriptomic profiles were examined. Biochar-conditioned ants exhibited improved survival (83.0% vs. 60.3% in non-pre-exposed ants) and significantly lower bioaccumulation of heavy metals, including a 32.8% reduction in Cd and a 32.9% reduction in Pb. Transcriptomic analysis revealed that biochar initiates a priming effect, which is sustained under stress through the co-enrichment of ribosome and proteasome pathways along with oxidative phosphorylation, thereby enhancing ant resilience to heavy metals. This was evidenced by a nearly twofold higher number of upregulated versus downregulated genes (1036 vs. 711) when biochar intervened in the stress response, prioritising protein homeostasis and activating key signalling cascades. Our findings demonstrate that biochar can actively "prime" the intrinsic defence systems of organisms. This study pioneers a biology centred framework for soil remediation, focusing on strengthening the resilience of organisms, which in turn maintains ecological functions and promotes long-term ecosystem stability in contaminated landscapes.
Liu et al. (Thu,) studied this question.