Mechanisms underlying mercury detoxification in soil–plant systems after selenium application: a review

• Published in: Environmental science and pollution research international 2021-09, Vol.28 (34), p.46852-46876
• Main Authors: Tran, Thi Anh Thu, Dinh, Quang Toan, Zhou, Fei, Zhai, Hui, Xue, Mingyue, Du, Zekun, Bañuelos, Gary S, Liang, Dongli
• Format: Article
• Language: English
• Subjects: Accumulation; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Bioavailability; Crops; Detoxification; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental science; Fertilizer application; Food safety; Food security; Health risk assessment; Health risks; Mercury; Mercury (metal); Mercury compounds; Plant growth; Plant production; Plant protection; Plant roots; Public health; Review Article; Reviews; Rhizosphere; Selenides; Selenium; Soil contamination; Soil pollution; Soils; Translocation; Waste Water Technology; Water Management; Water Pollution Control
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-021-15048-1

Feasible countermeasures to mitigate mercury (Hg) accumulation and its deleterious effects on crops are urgently needed worldwide. Selenium (Se) fertilizer application is a cost-effective strategy to reduce Hg concentrations, promote agro-environmental sustainability and food safety, and decrease the public health risk posed by Hg-contaminated soils and its accumulation in food crops. This holistic review focuses on the processes and detoxification mechanisms of Hg in whole soil–plant systems after Se application. The reduction of Hg bioavailability in soil, the formation of inert HgSe or/and HgSe-containing proteinaceous complexes in the rhizosphere and/or roots, and the reduction of plant root uptake and translocation of Hg in plant after Se application are systemically discussed. In addition, the positive responses in plant physiological and biochemical processes to Se application under Hg stress are presented to show the possible mechanisms for protecting the plant. However, application of high levels Se showed synergistic toxic effect with Hg and inhibited plant growth. The effectiveness of Se application methods, rates, and species on Hg detoxification is compared. This review provides a good approach for plant production in Hg-contaminated areas to meet food security demands and reduce the public health risk. Graphical abstract