Aims <p>Mercury (Hg) is a toxic and volatile pollutant that can bioaccumulate and biomagnify within plant-based food webs, thereby posing health risks to humans. However, our ability to mitigate Hg in crops remain limited, due to an insufficient understanding of its biogeochemical cycle within the soil–plant-atmosphere continuum. Consequently, a thorough understanding of how plants assimilate Hg from the environment, along with their associated biogeochemical and molecular responses, is essential for mitigating the associated environmental risks.</p> Methods <p>This study provides a critical review of Hg dynamics in the soil–plant-air system, synthesizing typical research published from 1993 to 2026. It aims to critically analyze and integrate knowledge, identify key research themes and main findings, and highlight emerging frontiers in Hg transport, plant response mechanisms, and mitigation strategies. The relevant data were sourced from the Web of Science Core Collection database and indexed by Scopus.</p> Results <p>This review delves into the intricate mechanisms underpinning Hg-induced toxicology in terrestrial plants, exploring the molecular and genetic networks that govern plant tolerance to Hg. Further, the mechanisms involved in Hg accumulation, compartmentation and detoxification within plants by critically discussing the roles of phytohormones, signal transduction networks, proteomic responses, and expression of genes were explored. Most importantly, we summarize the emerging techniques and propose future perspectives for the safe use of Hg-contaminated farmlands, with the goal of facilitating the mitigation of Hg from the edible tissues of crops.</p> Conclusions <p>Our review is helpful to the ongoing global efforts toward protecting public health by mitigating Hg in plant-based foods.</p> Graphical Abstract <p></p>