Shi et al. 2022 — Sulfur regulation of arsenic and cadmium translocation in wheat grain
This paper investigates how sulfur supplementation reduces the translocation of arsenic and cadmium from roots to shoots in wheat by promoting vacuolar sequestration in root cells. The study uses hydroponic wheat seedlings and reports root and shoot As and Cd concentrations under varying sulfur treatments. The paper also cites published field data showing that wheat grain from India, Pakistan, and Argentina has been found to contain inorganic arsenic at concentrations exceeding food safety thresholds, contextualizing the agronomic relevance of the findings.
Key numbers
- Sulfur supplementation reduced As translocation factor (root-to-shoot) by approximately 30–50% in hydroponic experiments (exact values in paper tables).
- Cd translocation similarly reduced by sulfur treatment.
- Citations to published iAs occurrence data in wheat grain: India (>200 µg/kg), Pakistan, Argentina — used as motivation for the study but primary data are from earlier published surveys.
- Analytical method: ICP-MS for As and Cd in plant tissue.
- Total As and iAs both referenced; speciation noted in cited occurrence studies.
Methods (brief)
Hydroponic wheat seedling experiment under controlled greenhouse conditions. Varying sulfur concentrations in nutrient solution. Root and shoot harvested separately and digested for ICP-MS analysis. Vacuolar sequestration assessed by fractionation. Paper is a mechanistic agronomic study, not a food occurrence survey; the wheat grain concentration values cited are from external published sources.
Note: This paper reports both total As and inorganic As (iAs) for the cited occurrence data; the primary experiment measures total As in plant tissue. The iAs and tAs fields are both listed because the paper discusses both, and the two are treated as non-interchangeable throughout the wiki.
Implications
Certification: Agronomic sulfur management is a lever for reducing As and Cd transfer to wheat grain; relevant for ingredient sourcing specifications and supplier agronomic guidance. Courses: Illustrates a soil/nutrient management mitigation strategy for As and Cd in wheat; connects to the vacuolar sequestration mechanism. App: Wheat grain can carry iAs from contaminated paddies; this paper documents the mechanism and references real-world occurrence data from South Asian and South American wheat-growing regions.