[Glu][H2PO4] modulates the absorption and translocation of cadmium and arsenic in rice

Abstract

The remediation of paddy fields contaminated by cadmium (Cd) and arsenic (As) is a global concern. In the present study, the field experiments were conducted to evaluate the effectiveness of foliar-applied [Glu][H₂PO₄] (Glu = glutamate) in reducing Cd and As accumulation in rice grains, while a hydroponic experiment under controlled Cd/As stress was used to examine whether this response was associated with changes in subcellular distribution and selected physiological indicators. Field experiments showed that foliar spraying with 0.2–1.5 mmol/L [Glu][H₂PO₄] reduced Cd accumulation by 6%–27% and 6%–26%, and As accumulation by 8%–24% and 8%–30% in early and late rice, respectively. In the hydroponic experiments, 1.5 mmol/L [Glu][H₂PO₄] was associated with markedly lower Cd and As contents in both roots and shoots. This treatment also coincided with a greater proportion of Cd in the cell-wall fraction, a greater proportion of As in the soluble fraction, and changes in selected chelation-related, antioxidant-related, and transporter-related indicators. Together, these results support the potential of foliar-applied [Glu][H₂PO₄] as a mitigation strategy for Cd/As-contaminated rice production and suggest that altered intracellular partitioning and detoxification-related responses may contribute to the reduced accumulation observed. However, the route-specific mechanism linking foliar application in the field to the responses observed in the seedling assay remains to be further clarified.

Keywords

[Glu][H2PO4] / Cadmium / Arsenic / Absorption / Transport / Chelation

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